1
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Zhu H, Yang Y, Duan Y, Zheng X, Lin Z, Zhou J. Nrf2/FSP1/CoQ10 axis-mediated ferroptosis is involved in sodium aescinate-induced nephrotoxicity. Arch Biochem Biophys 2024; 759:110100. [PMID: 39033970 DOI: 10.1016/j.abb.2024.110100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2024] [Revised: 07/15/2024] [Accepted: 07/16/2024] [Indexed: 07/23/2024]
Abstract
Sodium aescinate (SA), an active compound found in horse chestnut seeds, is widely used in clinical practice. Recently, the incidence of SA-induced adverse events, particularly renal impairment, has increased. Our previous work demonstrated that SA causes severe nephrotoxicity via nephrocyte ferroptosis; however, the underlying mechanism remains to be fully elucidated. In the current study, we investigated additional molecular pathways involved in SA-induced nephrotoxicity. Our results showed that SA inhibited cell viability, disrupted cellular membrane integrity, and enhanced reactive oxygen species (ROS), ferrous iron (Fe2+), and malondialdehyde (MDA) levels, as well as lipid peroxidation in rat proximal renal tubular epithelial cell line (NRK-52E) cells. SA also depleted coenzyme Q10 (CoQ10, ubiquinone) and nicotinamide adenine dinucleotide (NADH) and reduced ferroptosis suppressor protein 1 (FSP1) and polyprenyltransferase (coenzyme Q2, COQ2) activity, triggering lipid peroxidation and ROS accumulation in mouse kidneys and NRK-52E cells. The overexpression of COQ2, FSP1, or CoQ10 (ubiquinone) supplementation effectively attenuated SA-induced ferroptosis, whereas iFSP1 or 4-formylbenzoic acid (4-CBA) pretreatment exacerbated SA-induced nephrotoxicity. Additionally, SA decreased nuclear factor-erythroid-2-related factor 2 (Nrf2) levels and inhibited Nrf2 binding to the -1170/-1180 bp ARE site in FSP1 promoter, resulting in FSP1 suppression. Overexpression of Nrf2 or its agonist dimethyl fumarate (DMF) promoted FSP1 expression, thereby improving cellular antioxidant capacity and alleviating SA-induced ferroptosis. These results suggest that SA-triggers renal injury through oxidative stress and ferroptosis, driven by the suppression of the Nrf2/FSP1/CoQ10 axis.
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Affiliation(s)
- Haiyan Zhu
- School of Medicine, Yichun University, 576 XueFu Road, Yuanzhou District, Yichun, 336000, PR China
| | - Yijing Yang
- School of Medicine, Yichun University, 576 XueFu Road, Yuanzhou District, Yichun, 336000, PR China
| | - Yenan Duan
- School of Medicine, Yichun University, 576 XueFu Road, Yuanzhou District, Yichun, 336000, PR China
| | - Xin Zheng
- School of Medicine, Yichun University, 576 XueFu Road, Yuanzhou District, Yichun, 336000, PR China
| | - Zixiong Lin
- School of Medicine, Yichun University, 576 XueFu Road, Yuanzhou District, Yichun, 336000, PR China
| | - Jie Zhou
- School of Medicine, Yichun University, 576 XueFu Road, Yuanzhou District, Yichun, 336000, PR China.
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2
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Delaney M, Zhao Y, van de Leemput J, Lee H, Han Z. Actin Cytoskeleton and Integrin Components Are Interdependent for Slit Diaphragm Maintenance in Drosophila Nephrocytes. Cells 2024; 13:1350. [PMID: 39195240 DOI: 10.3390/cells13161350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2024] [Revised: 08/08/2024] [Accepted: 08/11/2024] [Indexed: 08/29/2024] Open
Abstract
In nephrotic syndrome, the podocyte filtration structures are damaged in a process called foot process effacement. This is mediated by the actin cytoskeleton; however, which actins are involved and how they interact with other filtration components, like the basement membrane, remains poorly understood. Here, we used the well-established Drosophila pericardial nephrocyte-the equivalent of podocytes in flies-knockdown models (RNAi) to study the interplay of the actin cytoskeleton (Act5C, Act57B, Act42A, and Act87E), alpha- and beta-integrin (basement membrane), and the slit diaphragm (Sns and Pyd). Knockdown of an actin gene led to variations of formation of actin stress fibers, the internalization of Sns, and a disrupted slit diaphragm cortical pattern. Notably, deficiency of Act5C, which resulted in complete absence of nephrocytes, could be partially mitigated by overexpressing Act42A or Act87E, suggesting at least partial functional redundancy. Integrin localized near the actin cytoskeleton as well as slit diaphragm components, but when the nephrocyte cytoskeleton or slit diaphragm was disrupted, this switched to colocalization, both at the surface and internalized in aggregates. Altogether, the data show that the interdependence of the slit diaphragm, actin cytoskeleton, and integrins is key to the structure and function of the Drosophila nephrocyte.
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Affiliation(s)
- Megan Delaney
- Center for Precision Disease Modeling, Department of Medicine, University of Maryland School of Medicine, 670 West Baltimore Street, Baltimore, MD 21201, USA
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, 670 West Baltimore Street, Baltimore, MD 21201, USA
| | - Yunpo Zhao
- Center for Precision Disease Modeling, Department of Medicine, University of Maryland School of Medicine, 670 West Baltimore Street, Baltimore, MD 21201, USA
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, 670 West Baltimore Street, Baltimore, MD 21201, USA
| | - Joyce van de Leemput
- Center for Precision Disease Modeling, Department of Medicine, University of Maryland School of Medicine, 670 West Baltimore Street, Baltimore, MD 21201, USA
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, 670 West Baltimore Street, Baltimore, MD 21201, USA
| | - Hangnoh Lee
- Center for Precision Disease Modeling, Department of Medicine, University of Maryland School of Medicine, 670 West Baltimore Street, Baltimore, MD 21201, USA
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, 670 West Baltimore Street, Baltimore, MD 21201, USA
| | - Zhe Han
- Center for Precision Disease Modeling, Department of Medicine, University of Maryland School of Medicine, 670 West Baltimore Street, Baltimore, MD 21201, USA
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, 670 West Baltimore Street, Baltimore, MD 21201, USA
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3
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van de Leemput J, Han Z. Drosophila Nephrocyte as a Model for Studying Glomerular Basement Membrane Physiology. J Am Soc Nephrol 2024; 35:00001751-990000000-00386. [PMID: 39115859 PMCID: PMC11387028 DOI: 10.1681/asn.0000000000000461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/13/2024] Open
Affiliation(s)
- Joyce van de Leemput
- Center for Precision Disease Modeling, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, and Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland
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4
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Zhu JY, Duan J, van de Leemput J, Han Z. Dysfunction of Mitochondrial Dynamics Induces Endocytosis Defect and Cell Damage in Drosophila Nephrocytes. Cells 2024; 13:1253. [PMID: 39120284 PMCID: PMC11312102 DOI: 10.3390/cells13151253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2024] [Revised: 07/16/2024] [Accepted: 07/24/2024] [Indexed: 08/10/2024] Open
Abstract
Mitochondria are crucial for cellular ATP production. They are highly dynamic organelles, whose morphology and function are controlled through mitochondrial fusion and fission. The specific roles of mitochondria in podocytes, the highly specialized cells of the kidney glomerulus, remain less understood. Given the significant structural, functional, and molecular similarities between mammalian podocytes and Drosophila nephrocytes, we employed fly nephrocytes to explore the roles of mitochondria in cellular function. Our study revealed that alterations in the Pink1-Park (mammalian PINK1-PRKN) pathway can disrupt mitochondrial dynamics in Drosophila nephrocytes. This disruption led to either fragmented or enlarged mitochondria, both of which impaired mitochondrial function. The mitochondrial dysfunction subsequently triggered defective intracellular endocytosis, protein aggregation, and cellular damage. These findings underscore the critical roles of mitochondria in nephrocyte functionality.
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Affiliation(s)
- Jun-yi Zhu
- Center for Precision Disease Modeling, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Division of Endocrinology, Diabetes, and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Jianli Duan
- Center for Precision Disease Modeling, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Division of Endocrinology, Diabetes, and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Joyce van de Leemput
- Center for Precision Disease Modeling, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Division of Endocrinology, Diabetes, and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Zhe Han
- Center for Precision Disease Modeling, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Division of Endocrinology, Diabetes, and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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5
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Castillo-Mancho V, Atienza-Manuel A, Sarmiento-Jiménez J, Ruiz-Gómez M, Culi J. Phospholipid scramblase 1: an essential component of the nephrocyte slit diaphragm. Cell Mol Life Sci 2024; 81:261. [PMID: 38878170 PMCID: PMC11335299 DOI: 10.1007/s00018-024-05287-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 05/03/2024] [Accepted: 05/20/2024] [Indexed: 06/29/2024]
Abstract
Blood ultrafiltration in nephrons critically depends on specialized intercellular junctions between podocytes, named slit diaphragms (SDs). Here, by studying a homologous structure found in Drosophila nephrocytes, we identify the phospholipid scramblase Scramb1 as an essential component of the SD, uncovering a novel link between membrane dynamics and SD formation. In scramb1 mutants, SDs fail to form. Instead, the SD components Sticks and stones/nephrin, Polychaetoid/ZO-1, and the Src-kinase Src64B/Fyn associate in cortical foci lacking the key SD protein Dumbfounded/NEPH1. Scramb1 interaction with Polychaetoid/ZO-1 and Flotillin2, the presence of essential putative palmitoylation sites and its capacity to oligomerize, suggest a function in promoting SD assembly within lipid raft microdomains. Furthermore, Scramb1 interactors as well as its functional sensitivity to temperature, suggest an active involvement in membrane remodeling processes during SD assembly. Remarkably, putative Ca2+-binding sites in Scramb1 are essential for its activity raising the possibility that Ca2+ signaling may control the assembly of SDs by impacting on Scramb1 activity.
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Affiliation(s)
- Vicente Castillo-Mancho
- Centro de Biología Molecular Severo Ochoa, CSIC and UAM, Nicolás Cabrera 1, Cantoblanco, Madrid, 28049, Spain
| | - Alexandra Atienza-Manuel
- Centro de Biología Molecular Severo Ochoa, CSIC and UAM, Nicolás Cabrera 1, Cantoblanco, Madrid, 28049, Spain
| | - Jorge Sarmiento-Jiménez
- Centro de Biología Molecular Severo Ochoa, CSIC and UAM, Nicolás Cabrera 1, Cantoblanco, Madrid, 28049, Spain
| | - Mar Ruiz-Gómez
- Centro de Biología Molecular Severo Ochoa, CSIC and UAM, Nicolás Cabrera 1, Cantoblanco, Madrid, 28049, Spain.
| | - Joaquim Culi
- Centro de Biología Molecular Severo Ochoa, CSIC and UAM, Nicolás Cabrera 1, Cantoblanco, Madrid, 28049, Spain.
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6
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Leroy C, Lang K, Spitz D, Milosavljevic J, Heinkele H, Kayser S, Helmstädter M, Walz G, Ulbrich MH, Hermle T. Linking Basement Membrane and Slit Diaphragm in Drosophila Nephrocytes. J Am Soc Nephrol 2024; 35:00001751-990000000-00329. [PMID: 38776165 PMCID: PMC11387032 DOI: 10.1681/asn.0000000000000400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 05/17/2024] [Indexed: 05/24/2024] Open
Abstract
Key Points
Drosophila nephrocytes feature a special basement membrane that may serve to model joint function of the glomerular filtration barrier.Silencing of Drosophila laminin and collagen IV genes reduced the density of slit diaphragms in nephrocytes, showing a direct effect of the matrix.Matrix receptor silencing phenocopied basement membrane disruption, indicating that the matrix guides slit diaphragm position through matrix receptors.
Background
The glomerular basement membrane and the slit diaphragm are essential parts of the filtration barrier. How these layers collaborate remains unclear. The podocyte-like nephrocytes in Drosophila harbor both a slit diaphragm and a basement membrane, serving as a model to address this critical question.
Methods
Basement membrane components and matrix receptors were silenced using RNA interference in nephrocytes. Slit diaphragms were analyzed using immunofluorescence, followed by automated quantification. Tracer endocytosis was applied for functional readouts.
Results
Immunofluorescence indicated a significant reduction in slit diaphragm density upon loss of laminin and collagen IV components. This was accompanied by reduced expression of fly nephrin and shallower membrane invaginations. Tracer studies revealed that the basement membrane defines properties of the nephrocyte filtration barrier. Acute enzymatic disruption of the basement membrane via collagenase rapidly caused slit diaphragm mislocalization and disintegration, which was independent of cell death. Loss of matrix-interacting receptors, particularly integrins mys and mew, phenocopied basement membrane disruption. Integrins and nephrin colocalized at the slit diaphragm in nephrocytes in a mutually dependent manner, interacting genetically. Human integrin α3 interacted physically with nephrin.
Conclusions
The glomerular basement membrane model in Drosophila nephrocytes reveals that matrix receptor–mediated cues ensure correct positioning of the slit diaphragm and the overall filtration barrier architecture.
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Grants
- HE 7456/4-1, HE 7456/7-1, and project-ID 431984000 â€" SFB 1453 Deutsche Forschungsgemeinschaft
- HE 7456/6-1 Deutsche Forschungsgemeinschaft
- HE 7456/4-1, HE 7456/7-1, and project-ID 431984000 - SFB 1453 Deutsche Forschungsgemeinschaft
- HE 7456/4-1, HE 7456/7-1, and project-ID 431984000 - SFB 1453 Deutsche Forschungsgemeinschaft
- HE 7456/4-1, HE 7456/7-1, and project-ID 431984000 - SFB 1453 Deutsche Forschungsgemeinschaft
- HE 7456/4-1, HE 7456/7-1, and project-ID 431984000 - SFB 1453 Deutsche Forschungsgemeinschaft
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Affiliation(s)
- Claire Leroy
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center - University of Freiburg, Freiburg, Germany
| | - Konrad Lang
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center - University of Freiburg, Freiburg, Germany
| | - Dominik Spitz
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center - University of Freiburg, Freiburg, Germany
| | - Julian Milosavljevic
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center - University of Freiburg, Freiburg, Germany
| | - Helena Heinkele
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center - University of Freiburg, Freiburg, Germany
| | - Séverine Kayser
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center - University of Freiburg, Freiburg, Germany
- EMcore, Renal Division, Department of Medicine, University Hospital Freiburg, University Faculty of Medicine, Freiburg, Germany
| | - Martin Helmstädter
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center - University of Freiburg, Freiburg, Germany
- EMcore, Renal Division, Department of Medicine, University Hospital Freiburg, University Faculty of Medicine, Freiburg, Germany
| | - Gerd Walz
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center - University of Freiburg, Freiburg, Germany
- CIBSS - Centre for Integrative Biological Signalling Studies, Freiburg, Germany
| | - Maximilian H Ulbrich
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Tobias Hermle
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center - University of Freiburg, Freiburg, Germany
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7
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Zhu JY, Fu Y, van de Leemput J, Yu Y, Li J, Ray PE, Han Z. HIV-1 Nef acts in synergy with APOL1-G1 to induce nephrocyte cell death in a new Drosophila model of HIV-related kidney diseases. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.08.584069. [PMID: 38496548 PMCID: PMC10942446 DOI: 10.1101/2024.03.08.584069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Background: People carrying two APOL1 risk alleles (RA) G1 or G2 are at greater risk of developing HIV-associated nephropathy (HIVAN). Studies in transgenic mice showed that the expression of HIV-1 genes in podocytes, and nef in particular, led to HIVAN. However, it remains unclear whether APOL1-RA and HIV-1 Nef interact to induce podocyte cell death. Method: We generated transgenic (Tg) flies that express APOL1-G1 (derived from a child with HIVAN) and HIV-1 nef specifically in the nephrocytes, the fly equivalent of mammalian podocytes, and assessed their individual and combined effects on the nephrocyte filtration structure and function. Results: We found that HIV-1 Nef acts in synergy with APOL1-G1 resulting in nephrocyte structural and functional defects. Specifically, HIV-1 Nef itself can induce endoplasmic reticulum (ER) stress without affecting autophagy. Furthermore, Nef exacerbates the organelle acidification defects and autophagy reduction induced by APOL1-G1. The synergy between HIV-1 Nef and APOL1-G1 is built on their joint effects on elevating ER stress, triggering nephrocyte dysfunction and ultimately cell death. Conclusions: Using a new Drosophila model of HIV-1-related kidney diseases, we identified ER stress as the converging point for the synergy between HIV-1 Nef and APOL1-G1 in inducing nephrocyte cell death. Given the high relevance between Drosophila nephrocytes and human podocytes, this finding suggests ER stress as a new therapeutic target for HIV-1 and APOL1-associated nephropathies.
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Duan J, Wen P, Zhao Y, van de Leemput J, Lai Yee J, Fermin D, Warady BA, Furth SL, Ng DK, Sampson MG, Han Z. A Drosophila model to screen Alport syndrome COL4A5 variants for their functional pathogenicity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.06.583697. [PMID: 38559272 PMCID: PMC10979928 DOI: 10.1101/2024.03.06.583697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Alport syndrome is a hereditary chronic kidney disease, attributed to rare pathogenic variants in either of three collagen genes (COL4A3/4/5) with most localized in COL4A5. Trimeric type IV Collagen α3α4α5 is essential for the glomerular basement membrane that forms the kidney filtration barrier. A means to functionally assess the many candidate variants and determine pathogenicity is urgently needed. We used Drosophila, an established model for kidney disease, and identify Col4a1 as the functional homolog of human COL4A5 in the fly nephrocyte (equivalent of human podocyte). Fly nephrocytes deficient for Col4a1 showed an irregular and thickened basement membrane and significantly reduced nephrocyte filtration function. This phenotype was restored by expressing human reference (wildtype) COL4A5, but not by COL4A5 carrying any of three established pathogenic patient-derived variants. We then screened seven additional patient COL4A5 variants; their ClinVar classification was either likely pathogenic or of uncertain significance. The findings support pathogenicity for four of these variants; the three others were found benign. Thus, demonstrating the effectiveness of this Drosophila in vivo kidney platform in providing the urgently needed variant-level functional validation.
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Affiliation(s)
- Jianli Duan
- Center for Precision Disease Modeling, Department of Medicine, University of Maryland School of Medicine, MD 21201, USA
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, MD 21201, USA
| | - Pei Wen
- Center for Precision Disease Modeling, Department of Medicine, University of Maryland School of Medicine, MD 21201, USA
| | - Yunpo Zhao
- Center for Precision Disease Modeling, Department of Medicine, University of Maryland School of Medicine, MD 21201, USA
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, MD 21201, USA
| | - Joyce van de Leemput
- Center for Precision Disease Modeling, Department of Medicine, University of Maryland School of Medicine, MD 21201, USA
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, MD 21201, USA
| | - Jennifer Lai Yee
- Division of Nephrology, Department of Pediatric, University of Michigan School of Medicine, Ann Arbor, MI 48105, USA
| | - Damian Fermin
- Division of Nephrology, Department of Internal Medicine, University of Michigan School of Medicine, Ann Arbor, MI 48105, USA
| | - Bradley A Warady
- Division of Pediatric Nephrology, Children’s Mercy Kansas City, Kansas City, MO 64108, USA
| | - Susan L Furth
- Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Division of Nephrology, Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Derek K Ng
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, MD 21205, USA
| | - Matthew G Sampson
- Division of Nephrology, Department of Pediatrics, Boston Children’s Hospital, Boston, MA 02115, USA
- Harvard Medical School Boston, MA 02115, USA
- Kidney Disease Initiative, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Zhe Han
- Center for Precision Disease Modeling, Department of Medicine, University of Maryland School of Medicine, MD 21201, USA
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, MD 21201, USA
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9
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Sachs W, Blume L, Loreth D, Schebsdat L, Hatje F, Koehler S, Wedekind U, Sachs M, Zieliniski S, Brand J, Conze C, Florea BI, Heppner F, Krüger E, Rinschen MM, Kretz O, Thünauer R, Meyer-Schwesinger C. The proteasome modulates endocytosis specifically in glomerular cells to promote kidney filtration. Nat Commun 2024; 15:1897. [PMID: 38429282 PMCID: PMC10907641 DOI: 10.1038/s41467-024-46273-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 02/16/2024] [Indexed: 03/03/2024] Open
Abstract
Kidney filtration is ensured by the interaction of podocytes, endothelial and mesangial cells. Immunoglobulin accumulation at the filtration barrier is pathognomonic for glomerular injury. The mechanisms that regulate filter permeability are unknown. Here, we identify a pivotal role for the proteasome in a specific cell type. Combining genetic and inhibitor-based human, pig, mouse, and Drosophila models we demonstrate that the proteasome maintains filtration barrier integrity, with podocytes requiring the constitutive and glomerular endothelial cells the immunoproteasomal activity. Endothelial immunoproteasome deficiency as well as proteasome inhibition disrupt the filtration barrier in mice, resulting in pathologic immunoglobulin deposition. Mechanistically, we observe reduced endocytic activity, which leads to altered membrane recycling and endocytic receptor turnover. This work expands the concept of the (immuno)proteasome as a control protease orchestrating protein degradation and antigen presentation and endocytosis, providing new therapeutic targets to treat disease-associated glomerular protein accumulations.
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Affiliation(s)
- Wiebke Sachs
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center of Kidney Health, Hamburg, Germany
| | - Lukas Blume
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center of Kidney Health, Hamburg, Germany
| | - Desiree Loreth
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center of Kidney Health, Hamburg, Germany
| | - Lisa Schebsdat
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center of Kidney Health, Hamburg, Germany
| | - Favian Hatje
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center of Kidney Health, Hamburg, Germany
| | - Sybille Koehler
- Hamburg Center of Kidney Health, Hamburg, Germany
- Nephrology, III Medical Clinic, Department of Internal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Uta Wedekind
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center of Kidney Health, Hamburg, Germany
| | - Marlies Sachs
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center of Kidney Health, Hamburg, Germany
| | - Stephanie Zieliniski
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center of Kidney Health, Hamburg, Germany
| | - Johannes Brand
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center of Kidney Health, Hamburg, Germany
| | | | - Bogdan I Florea
- Bio-Organic Synthesis Group, Leiden University, Leiden, The Netherlands
| | - Frank Heppner
- Institute of Neuropathology, Charité, Berlin, Germany
| | - Elke Krüger
- Institute of Medical Biochemistry and Molecular Biology, University Medicine Greifswald, Greifswald, Germany
| | - Markus M Rinschen
- Hamburg Center of Kidney Health, Hamburg, Germany
- Nephrology, III Medical Clinic, Department of Internal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Oliver Kretz
- Hamburg Center of Kidney Health, Hamburg, Germany
- Nephrology, III Medical Clinic, Department of Internal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Roland Thünauer
- Leibniz Institute of Virology, Hamburg, Germany
- Technology Platform Light Microscopy (TPLM), University Hamburg, Hamburg, Germany
- Advanced Light and Fluorescence Microscopy (ALFM) Facility at the Centre for Structural Systems Biology (CSSB), Hamburg, Germany
| | - Catherine Meyer-Schwesinger
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
- Hamburg Center of Kidney Health, Hamburg, Germany.
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10
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Xi G, Lamba SA, Mysh M, Poulton JS. Oxidative Stress Contributes to Slit Diaphragm Defects Caused by Disruption of Endocytosis. Kidney Int Rep 2024; 9:451-463. [PMID: 38344712 PMCID: PMC10851022 DOI: 10.1016/j.ekir.2023.11.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 10/27/2023] [Accepted: 11/20/2023] [Indexed: 03/04/2024] Open
Abstract
Introduction Podocyte slit diaphragms are an important component of the glomerular filtration barrier. Podocyte injury frequently includes defects in slit diaphragms, and various mechanisms for these defects have been described, including altered endocytic trafficking of slit diaphragm proteins or oxidative stress. However, the potential relationship between endocytosis and oxidative stress in the context of slit diaphragm integrity has not been extensively considered. Methods To examine the potential relationships between endocytosis, oxidative stress, and slit diaphragm integrity, we induced genetic or pharmacological disruption of endocytosis in Drosophila nephrocytes (the insect orthologue of podocytes) and cultured human podocytes. We then employed immunofluorescence microscopy to analyze protein localization and levels, and to quantify signal from reactive oxygen species (ROS) dyes. Immunoprecipitation from podocyte cell lysates was used to examine effects on slit diaphragm protein complex formation (i.e., nephrin/podocin and nephrin/ZO-1). Results Disruption of endocytosis in nephrocytes and podocytes led to slit diaphragm defects, elevated levels of ROS (oxidative stress), and activation of the nuclear factor erythroid 2-related factor 2 (Nrf2) antioxidant pathway. In nephrocytes with defective endocytosis, perturbation of Nrf2 signaling exacerbated slit diaphragm defects. Conversely, overexpression of Nrf2 target genes catalase or glucose-6-phosphate dehydrogenase (G6PD) significantly ameliorated slit diaphragm defects caused by disruption of endocytosis. Conclusion Oxidative stress is an important consequence of defective endocytosis and contributes to the defects in slit diaphragm integrity associated with disruption of endocytic trafficking.
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Affiliation(s)
- Gang Xi
- UNC Kidney Center, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Sajan A. Lamba
- UNC Kidney Center, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Michael Mysh
- UNC Kidney Center, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - John S. Poulton
- UNC Kidney Center, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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11
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Koehler S, Huber TB. Insights into human kidney function from the study of Drosophila. Pediatr Nephrol 2023; 38:3875-3887. [PMID: 37171583 PMCID: PMC10584755 DOI: 10.1007/s00467-023-05996-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 04/13/2023] [Accepted: 04/18/2023] [Indexed: 05/13/2023]
Abstract
Biological and biomedical research using Drosophila melanogaster as a model organism has gained recognition through several Nobel prizes within the last 100 years. Drosophila exhibits several advantages when compared to other in vivo models such as mice and rats, as its life cycle is very short, animal maintenance is easy and inexpensive and a huge variety of transgenic strains and tools are publicly available. Moreover, more than 70% of human disease-causing genes are highly conserved in the fruit fly. Here, we explain the use of Drosophila in nephrology research and describe two kidney tissues, Malpighian tubules and the nephrocytes. The latter are the homologous cells to mammalian glomerular podocytes and helped to provide insights into a variety of signaling pathways due to the high morphological similarities and the conserved molecular make-up between nephrocytes and podocytes. In recent years, nephrocytes have also been used to study inter-organ communication as links between nephrocytes and the heart, the immune system and the muscles have been described. In addition, other tissues such as the eye and the reproductive system can be used to study the functional role of proteins being part of the kidney filtration barrier.
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Affiliation(s)
- Sybille Koehler
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
| | - Tobias B Huber
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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12
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Rogg M, Maier JI, Helmstädter M, Sammarco A, Kliewe F, Kretz O, Weißer L, Van Wymersch C, Findeisen K, Koessinger AL, Tsoy O, Baumbach J, Grabbert M, Werner M, Huber TB, Endlich N, Schilling O, Schell C. A YAP/TAZ-ARHGAP29-RhoA Signaling Axis Regulates Podocyte Protrusions and Integrin Adhesions. Cells 2023; 12:1795. [PMID: 37443829 PMCID: PMC10340513 DOI: 10.3390/cells12131795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 06/28/2023] [Accepted: 07/01/2023] [Indexed: 07/15/2023] Open
Abstract
Glomerular disease due to podocyte malfunction is a major factor in the pathogenesis of chronic kidney disease. Identification of podocyte-specific signaling pathways is therefore a prerequisite to characterizing relevant disease pathways and developing novel treatment approaches. Here, we employed loss of function studies for EPB41L5 (Yurt) as a central podocyte gene to generate a cell type-specific disease model. Loss of Yurt in fly nephrocytes caused protein uptake and slit diaphragm defects. Transcriptomic and proteomic analysis of human EPB41L5 knockout podocytes demonstrated impaired mechanotransduction via the YAP/TAZ signaling pathway. Further analysis of specific inhibition of the YAP/TAZ-TEAD transcription factor complex by TEADi led to the identification of ARGHAP29 as an EPB41L5 and YAP/TAZ-dependently expressed podocyte RhoGAP. Knockdown of ARHGAP29 caused increased RhoA activation, defective lamellipodia formation, and increased maturation of integrin adhesion complexes, explaining similar phenotypes caused by loss of EPB41L5 and TEADi expression in podocytes. Detection of increased levels of ARHGAP29 in early disease stages of human glomerular disease implies a novel negative feedback loop for mechanotransductive RhoA-YAP/TAZ signaling in podocyte physiology and disease.
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Affiliation(s)
- Manuel Rogg
- Institute of Surgical Pathology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Jasmin I. Maier
- Institute of Surgical Pathology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Martin Helmstädter
- Department of Medicine IV, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Alena Sammarco
- Institute of Surgical Pathology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Felix Kliewe
- Department of Anatomy and Cell Biology, University Medicine Greifswald, 17489 Greifswald, Germany (N.E.)
| | - Oliver Kretz
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Lisa Weißer
- Institute of Surgical Pathology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Clara Van Wymersch
- Institute of Surgical Pathology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Karla Findeisen
- Institute of Surgical Pathology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Anna L. Koessinger
- Institute of Surgical Pathology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Olga Tsoy
- Institute for Computational Systems Biology, University of Hamburg, 22607 Hamburg, Germany; (O.T.)
| | - Jan Baumbach
- Institute for Computational Systems Biology, University of Hamburg, 22607 Hamburg, Germany; (O.T.)
- Department of Mathematics and Computer Science, University of Southern Denmark, 5230 Odense, Denmark
| | - Markus Grabbert
- Department of Urology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Martin Werner
- Institute of Surgical Pathology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Tobias B. Huber
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Nicole Endlich
- Department of Anatomy and Cell Biology, University Medicine Greifswald, 17489 Greifswald, Germany (N.E.)
| | - Oliver Schilling
- Institute of Surgical Pathology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
- Freiburg Institute for Advanced Studies (FRIAS), University of Freiburg, 79106 Freiburg, Germany
| | - Christoph Schell
- Institute of Surgical Pathology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
- Freiburg Institute for Advanced Studies (FRIAS), University of Freiburg, 79106 Freiburg, Germany
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13
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Gilhaus K, Cepok C, Kamm D, Surmann B, Nedvetsky PI, Emich J, Sundukova A, Saatkamp K, Nüsse H, Klingauf J, Wennmann DO, George B, Krahn MP, Pavenstädt HJ, Vollenbröker BA. Activation of Hippo Pathway Damages Slit Diaphragm by Deprivation of Ajuba Proteins. J Am Soc Nephrol 2023; 34:1039-1055. [PMID: 36930055 PMCID: PMC10278832 DOI: 10.1681/asn.0000000000000107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 02/06/2023] [Indexed: 03/18/2023] Open
Abstract
SIGNIFICANCE STATEMENT Nuclear exclusion of the cotranscription factor YAP, which is a consequence of activation of the Hippo signaling pathway, leads to FSGS and podocyte apoptosis. Ajuba proteins play an important role in the glomerular filtration barrier by keeping the Hippo pathway inactive. In nephrocytes from Drosophila melanogaster , a well-established model system for podocyte research, Ajuba proteins ensure slit diaphragm (SD) formation and function. Hippo pathway activation leads to mislocalization of Ajuba proteins, decreased SD formation, rearrangement of the actin cytoskeleton, and increased SD permeability. Targeting the kinases of the Hippo pathway with specific inhibitors in the glomerulus could, therefore, be a promising strategy for therapy of FSGS. BACKGROUND The highly conserved Hippo pathway, which regulates organ growth and cell proliferation by inhibiting transcriptional cofactors YAP/TAZ, plays a special role in podocytes, where activation of the pathway leads to apoptosis. The Ajuba family proteins (Ajuba, LIM domain-containing protein 1 (LIMD1) and Wilms tumor protein 1-interacting protein [WTIP]) can bind and inactivate large tumor suppressor kinases 1 and 2, (LATS1/2) two of the Hippo pathway key kinases. WTIP, furthermore, connects the slit diaphragm (SD), the specialized cell-cell junction between podocytes, with the actin cytoskeleton. METHODS We used garland cell nephrocytes of Drosophila melanogaster to monitor the role of Ajuba proteins in Hippo pathway regulation and structural integrity of the SD. Microscopy and functional assays analyzed the interplay between Ajuba proteins and LATS2 regarding expression, localization, interaction, and effects on the functionality of the SD. RESULTS In nephrocytes, the Ajuba homolog Djub recruited Warts (LATS2 homolog) to the SD. Knockdown of Djub activated the Hippo pathway. Reciprocally, Hippo activation reduced the Djub level. Both Djub knockdown and Hippo activation led to morphological changes in the SD, rearrangement of the cortical actin cytoskeleton, and increased SD permeability. Knockdown of Warts or overexpression of constitutively active Yki prevented these effects. In podocytes, Hippo pathway activation or knockdown of YAP also decreased the level of Ajuba proteins. CONCLUSIONS Ajuba proteins regulate the structure and function of the SD in nephrocytes, connecting the SD protein complex to the actin cytoskeleton and maintaining the Hippo pathway in an inactive state. Hippo pathway activation directly influencing Djub expression suggests a self-amplifying feedback mechanism.
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Affiliation(s)
- Kevin Gilhaus
- Molecular Nephrology, Medical Clinic D, University Hospital of Münster, Münster, Germany
| | - Claudia Cepok
- Molecular Nephrology, Medical Clinic D, University Hospital of Münster, Münster, Germany
| | - David Kamm
- Molecular Nephrology, Medical Clinic D, University Hospital of Münster, Münster, Germany
| | - Beate Surmann
- Molecular Nephrology, Medical Clinic D, University Hospital of Münster, Münster, Germany
| | - Pavel I. Nedvetsky
- Medical Cell Biology, Medical Clinic D, University Hospital of Münster, Münster, Germany
| | - Jana Emich
- Institute of Reproductive Genetics, University Hospital of Münster, Münster, Germany
| | - Alina Sundukova
- Molecular Nephrology, Medical Clinic D, University Hospital of Münster, Münster, Germany
| | - Katharina Saatkamp
- Molecular Nephrology, Medical Clinic D, University Hospital of Münster, Münster, Germany
| | - Harald Nüsse
- Institute of Medical Physics and Biophysics, Westfälische-Wilhelms University Münster, Münster, Germany
| | - Jürgen Klingauf
- Institute of Medical Physics and Biophysics, Westfälische-Wilhelms University Münster, Münster, Germany
| | - Dirk O. Wennmann
- Molecular Nephrology, Medical Clinic D, University Hospital of Münster, Münster, Germany
| | - Britta George
- Molecular Nephrology, Medical Clinic D, University Hospital of Münster, Münster, Germany
| | - Michael P. Krahn
- Medical Cell Biology, Medical Clinic D, University Hospital of Münster, Münster, Germany
| | | | - Beate A. Vollenbröker
- Molecular Nephrology, Medical Clinic D, University Hospital of Münster, Münster, Germany
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14
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Boettcher S, Simons M. Model organisms for functional validation in genetic renal disease. MED GENET-BERLIN 2022; 34:287-296. [PMID: 38836086 PMCID: PMC11006349 DOI: 10.1515/medgen-2022-2162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2024]
Abstract
Functional validation is key for establishing new disease genes in human genetics. Over the years, model organisms have been utilized in a very effective manner to prove causality of genes or genetic variants for a wide variety of diseases. Also in hereditary renal disease, model organisms are very helpful for functional validation of candidate genes and variants identified by next-generation sequencing strategies and for obtaining insights into the pathophysiology. Due to high genetic conservation as well as high anatomical and physiological similarities with the human kidney, almost all genetic kidney diseases can be studied in the mouse. However, mouse work is time consuming and expensive, so there is a need for alternative models. In this review, we will provide an overview of model organisms used in renal research, focusing on mouse, zebrafish, frog, and fruit flies.
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Affiliation(s)
- Susanne Boettcher
- Sektion Nephrogenetik, Institute of Human Genetics, University Hospital Heidelberg, 69120 Heidelberg, Germany
| | - Matias Simons
- Sektion Nephrogenetik, Institute of Human Genetics, University Hospital Heidelberg, 69120 Heidelberg, Germany
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15
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Milosavljevic J, Lempicki C, Lang K, Heinkele H, Kampf LL, Leroy C, Chen M, Gerstner L, Spitz D, Wang M, Knob AU, Kayser S, Helmstädter M, Walz G, Pollak MR, Hermle T. Nephrotic Syndrome Gene TBC1D8B Is Required for Endosomal Maturation and Nephrin Endocytosis in Drosophila. J Am Soc Nephrol 2022; 33:2174-2193. [PMID: 36137753 PMCID: PMC9731638 DOI: 10.1681/asn.2022030275] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 09/01/2022] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Variants in TBC1D8B cause nephrotic syndrome. TBC1D8B is a GTPase-activating protein for Rab11 (RAB11-GAP) that interacts with nephrin, but how it controls nephrin trafficking or other podocyte functions remains unclear. METHODS We generated a stable deletion in Tbc1d8b and used microhomology-mediated end-joining for genome editing. Ex vivo functional assays utilized slit diaphragms in podocyte-like Drosophila nephrocytes. Manipulation of endocytic regulators and transgenesis of murine Tbc1d8b provided a comprehensive functional analysis of Tbc1d8b. RESULTS A null allele of Drosophila TBC1D8B exhibited a nephrocyte-restricted phenotype of nephrin mislocalization, similar to patients with isolated nephrotic syndrome who have variants in the gene. The protein was required for rapid nephrin turnover in nephrocytes and for endocytosis of nephrin induced by excessive Rab5 activity. The protein expressed from the Tbc1d8b locus bearing the edited tag predominantly localized to mature early and late endosomes. Tbc1d8b was required for endocytic cargo processing and degradation. Silencing Hrs, a regulator of endosomal maturation, phenocopied loss of Tbc1d8b. Low-level expression of murine TBC1D8B rescued loss of the Drosophila gene, indicating evolutionary conservation. Excessive murine TBC1D8B selectively disturbed nephrin dynamics. Finally, we discovered four novel TBC1D8B variants within a cohort of 363 patients with FSGS and validated a functional effect of two variants in Drosophila, suggesting a personalized platform for TBC1D8B-associated FSGS. CONCLUSIONS Variants in TBC1D8B are not infrequent among patients with FSGS. TBC1D8B, functioning in endosomal maturation and degradation, is essential for nephrin trafficking.
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Affiliation(s)
- Julian Milosavljevic
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Camille Lempicki
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Konrad Lang
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Helena Heinkele
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Lina L. Kampf
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Claire Leroy
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Mengmeng Chen
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Lea Gerstner
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Dominik Spitz
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Minxian Wang
- Division of Nephrology, Beth Israel Deaconess Medical Center, Boston, Massachusetts
- Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | - Andrea U. Knob
- Division of Nephrology, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Séverine Kayser
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Martin Helmstädter
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Gerd Walz
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
- CIBSS–Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Martin R. Pollak
- Division of Nephrology, Beth Israel Deaconess Medical Center, Boston, Massachusetts
- Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | - Tobias Hermle
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
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16
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Odenthal J, Dittrich S, Ludwig V, Merz T, Reitmeier K, Reusch B, Höhne M, Cosgun ZC, Hohenadel M, Putnik J, Göbel H, Rinschen MM, Altmüller J, Koehler S, Schermer B, Benzing T, Beck BB, Brinkkötter PT, Habbig S, Bartram MP. Modeling of ACTN4-Based Podocytopathy Using Drosophila Nephrocytes. Kidney Int Rep 2022; 8:317-329. [PMID: 36815115 PMCID: PMC9939316 DOI: 10.1016/j.ekir.2022.10.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 10/17/2022] [Accepted: 10/24/2022] [Indexed: 11/06/2022] Open
Abstract
Introduction Genetic disorders are among the most prevalent causes leading to progressive glomerular disease and, ultimately, end-stage renal disease (ESRD) in children and adolescents. Identification of underlying genetic causes is indispensable for targeted treatment strategies and counseling of affected patients and their families. Methods Here, we report on a boy who presented at 4 years of age with proteinuria and biopsy-proven focal segmental glomerulosclerosis (FSGS) that was temporarily responsive to treatment with ciclosporin A. Molecular genetic testing identified a novel mutation in alpha-actinin-4 (p.M240T). We describe a feasible and efficient experimental approach to test its pathogenicity by combining in silico, in vitro, and in vivo analyses. Results The de novo p.M240T mutation led to decreased alpha-actinin-4 stability as well as protein mislocalization and actin cytoskeleton rearrangements. Transgenic expression of wild-type human alpha-actinin-4 in Drosophila melanogaster nephrocytes was able to ameliorate phenotypes associated with the knockdown of endogenous actinin. In contrast, p.M240T, as well as other established disease variants p.W59R and p.K255E, failed to rescue these phenotypes, underlining the pathogenicity of the novel alpha-actinin-4 variant. Conclusion Our data highlight that the newly identified alpha-actinin-4 mutation indeed encodes for a disease-causing variant of the protein and promote the Drosophila model as a simple and convenient tool to study monogenic kidney disease in vivo.
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Affiliation(s)
- Johanna Odenthal
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Sebastian Dittrich
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Vivian Ludwig
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Tim Merz
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Katrin Reitmeier
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Björn Reusch
- Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany,Institute of Human Genetics, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Martin Höhne
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Zülfü C. Cosgun
- Department of Pediatrics, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Maximilian Hohenadel
- Department of Pediatrics, Division of Pediatric Nephrology, University of Bonn, Bonn, Germany
| | - Jovana Putnik
- Mother and Child Health Care Institute of Serbia “Dr Vukan Čupić,” Department of Nephrology, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Heike Göbel
- Institute of Pathology, University Hospital of Cologne, Cologne, Germany
| | - Markus M. Rinschen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark,Aarhus Institute of Advanced Studies, Aarhus University, Aarhus, Denmark,III Medical Clinic, University Hospital Hamburg Eppendorf, Hamburg, Germany
| | - Janine Altmüller
- Berlin Institute of Health at Charité-Universitätsmedizin Berlin, Max Delbrück Center for Molecular Medicine, Berlin, Germany,Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Sybille Koehler
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Bernhard Schermer
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Thomas Benzing
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Bodo B. Beck
- Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany,Institute of Human Genetics, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Paul T. Brinkkötter
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany,Correspondence: Paul T. Brinkkoetter, Department II of Internal Medicine, Faculty of Medicine, University of Cologne, University Hospital Cologne, Kerpener Street 62, Cologne 50935, Germany.
| | - Sandra Habbig
- Department of Pediatrics, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Malte P. Bartram
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
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A slit-diaphragm-associated protein network for dynamic control of renal filtration. Nat Commun 2022; 13:6446. [PMID: 36307401 PMCID: PMC9616960 DOI: 10.1038/s41467-022-33748-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 09/29/2022] [Indexed: 12/25/2022] Open
Abstract
The filtration of blood in the kidney which is crucial for mammalian life is determined by the slit-diaphragm, a cell-cell junction between the foot processes of renal podocytes. The slit-diaphragm is thought to operate as final barrier or as molecular sensor of renal filtration. Using high-resolution proteomic analysis of slit-diaphragms affinity-isolated from rodent kidney, we show that the native slit-diaphragm is built from the junction-forming components Nephrin, Neph1 and Podocin and a co-assembled high-molecular weight network of proteins. The network constituents cover distinct classes of proteins including signaling-receptors, kinases/phosphatases, transporters and scaffolds. Knockout or knock-down of either the core components or the selected network constituents tyrosine kinase MER (MERTK), atrial natriuretic peptide-receptor C (ANPRC), integral membrane protein 2B (ITM2B), membrane-associated guanylate-kinase, WW and PDZ-domain-containing protein1 (MAGI1) and amyloid protein A4 resulted in target-specific impairment or disruption of the filtration process. Our results identify the slit-diaphragm as a multi-component system that is endowed with context-dependent dynamics via a co-assembled protein network.
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18
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Koehler S, Huber TB, Denholm B. A protective role for <i>Drosophila</i> Filamin in nephrocytes via Yorkie mediated hypertrophy. Life Sci Alliance 2022; 5:e202101281. [PMID: 35922155 PMCID: PMC9351128 DOI: 10.26508/lsa.202101281] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 07/15/2022] [Accepted: 07/18/2022] [Indexed: 11/24/2022] Open
Abstract
Podocytes are specialized epithelial cells of the kidney glomerulus and are an essential part of the filtration barrier. Because of their position, they are exposed to constant biomechanical forces such as shear stress and hydrostatic pressure. These forces increase during disease, resulting in podocyte injury. It is likely podocytes have adaptative responses to help buffer against deleterious mechanical force and thus reduce injury. However, these responses remain largely unknown. Here, using the <i>Drosophila</i> model, we show the mechanosensor Cheerio (dFilamin) provides a key protective role in nephrocytes. We found expression of an activated mechanosensitive variant of Cheerio rescued filtration function and induced compensatory and hypertrophic growth in nephrocytes depleted of the nephrocyte diaphragm proteins Sns or Duf. Delineating the protective pathway downstream of Cheerio we found repression of the Hippo pathway induces nephrocyte hypertrophy, whereas Hippo activation reversed the Cheerio-mediated hypertrophy. Furthermore, we find Yorkie was activated upon expression of active Cheerio. Taken together, our data suggest that Cheerio acts via the Hippo pathway to induce hypertrophic growth, as a protective response in abnormal nephrocytes.
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Affiliation(s)
- Sybille Koehler
- Biomedical Sciences, University of Edinburgh, Edinburgh, UK
- III Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Tobias B Huber
- III Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Barry Denholm
- Biomedical Sciences, University of Edinburgh, Edinburgh, UK
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19
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Lang K, Milosavljevic J, Heinkele H, Chen M, Gerstner L, Spitz D, Kayser S, Helmstädter M, Walz G, Köttgen M, Spracklen A, Poulton J, Hermle T. Selective endocytosis controls slit diaphragm maintenance and dynamics in Drosophila nephrocytes. eLife 2022; 11:79037. [PMID: 35876643 PMCID: PMC9355562 DOI: 10.7554/elife.79037] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 07/24/2022] [Indexed: 11/28/2022] Open
Abstract
The kidneys generate about 180 l of primary urine per day by filtration of plasma. An essential part of the filtration barrier is the slit diaphragm, a multiprotein complex containing nephrin as major component. Filter dysfunction typically manifests with proteinuria and mutations in endocytosis regulating genes were discovered as causes of proteinuria. However, it is unclear how endocytosis regulates the slit diaphragm and how the filtration barrier is maintained without either protein leakage or filter clogging. Here, we study nephrin dynamics in podocyte-like nephrocytes of Drosophila and show that selective endocytosis either by dynamin- or flotillin-mediated pathways regulates a stable yet highly dynamic architecture. Short-term manipulation of endocytic functions indicates that dynamin-mediated endocytosis of ectopic nephrin restricts slit diaphragm formation spatially while flotillin-mediated turnover of nephrin within the slit diaphragm is needed to maintain filter permeability by shedding of molecules bound to nephrin in endosomes. Since slit diaphragms cannot be studied in vitro and are poorly accessible in mouse models, this is the first analysis of their dynamics within the slit diaphragm multiprotein complex. Identification of the mechanisms of slit diaphragm maintenance will help to develop novel therapies for proteinuric renal diseases that are frequently limited to symptomatic treatment.
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Affiliation(s)
- Konrad Lang
- Department of Medicine, University of Freiburg, Freiburg, Germany
| | | | - Helena Heinkele
- Department of Medicine, University of Freiburg, Freiburg, Germany
| | - Mengmeng Chen
- Department of Medicine, University of Freiburg, Freiburg, Germany
| | - Lea Gerstner
- Department of Medicine, University of Freiburg, Freiburg, Germany
| | - Dominik Spitz
- Department of Medicine, University of Freiburg, Freiburg, Germany
| | - Severine Kayser
- Department of Medicine, University of Freiburg, Freiburg, Germany
| | | | - Gerd Walz
- Department of Medicine, University of Freiburg, Freiburg, Germany
| | - Michael Köttgen
- Department of Medicine, University of Freiburg, Freiburg, Germany
| | - Andrew Spracklen
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - John Poulton
- Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - Tobias Hermle
- Department of Medicine, University of Freiburg, Freiburg, Germany
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20
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Spitz D, Comas M, Gerstner L, Kayser S, Helmstädter M, Walz G, Hermle T. mTOR-Dependent Autophagy Regulates Slit Diaphragm Density in Podocyte-like Drosophila Nephrocytes. Cells 2022; 11:2103. [PMID: 35805186 PMCID: PMC9265458 DOI: 10.3390/cells11132103] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 06/24/2022] [Accepted: 06/28/2022] [Indexed: 02/04/2023] Open
Abstract
Both mTOR signaling and autophagy are important modulators of podocyte homeostasis, regeneration, and aging and have been implicated in glomerular diseases. However, the mechanistic role of these pathways for the glomerular filtration barrier remains poorly understood. We used Drosophila nephrocytes as an established podocyte model and found that inhibition of mTOR signaling resulted in increased spacing between slit diaphragms. Gain-of-function of mTOR signaling did not affect spacing, suggesting that additional cues limit the maximal slit diaphragm density. Interestingly, both activation and inhibition of mTOR signaling led to decreased nephrocyte function, indicating that a fine balance of signaling activity is needed for proper function. Furthermore, mTOR positively controlled cell size, survival, and the extent of the subcortical actin network. We also showed that basal autophagy in nephrocytes is required for survival and limits the expression of the sns (nephrin) but does not directly affect slit diaphragm formation or endocytic activity. However, using a genetic rescue approach, we demonstrated that excessive, mTOR-dependent autophagy is primarily responsible for slit diaphragm misspacing. In conclusion, we established this invertebrate podocyte model for mechanistic studies on the role of mTOR signaling and autophagy, and we discovered a direct mTOR/autophagy-dependent regulation of the slit diaphragm architecture.
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Affiliation(s)
- Dominik Spitz
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, 79106 Freiburg, Germany; (D.S.); (L.G.); (S.K.); (M.H.); (G.W.)
| | - Maria Comas
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, 79106 Freiburg, Germany; (D.S.); (L.G.); (S.K.); (M.H.); (G.W.)
| | - Lea Gerstner
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, 79106 Freiburg, Germany; (D.S.); (L.G.); (S.K.); (M.H.); (G.W.)
| | - Séverine Kayser
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, 79106 Freiburg, Germany; (D.S.); (L.G.); (S.K.); (M.H.); (G.W.)
| | - Martin Helmstädter
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, 79106 Freiburg, Germany; (D.S.); (L.G.); (S.K.); (M.H.); (G.W.)
| | - Gerd Walz
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, 79106 Freiburg, Germany; (D.S.); (L.G.); (S.K.); (M.H.); (G.W.)
- CIBSS—Centre for Integrative Biological Signalling Studies, 79106 Freiburg, Germany
| | - Tobias Hermle
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, 79106 Freiburg, Germany; (D.S.); (L.G.); (S.K.); (M.H.); (G.W.)
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21
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Dow JAT, Simons M, Romero MF. Drosophila melanogaster: a simple genetic model of kidney structure, function and disease. Nat Rev Nephrol 2022; 18:417-434. [PMID: 35411063 DOI: 10.1038/s41581-022-00561-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/07/2022] [Indexed: 12/27/2022]
Abstract
Although the genetic basis of many kidney diseases is being rapidly elucidated, their experimental study remains problematic owing to the lack of suitable models. The fruitfly Drosophila melanogaster provides a rapid, ethical and cost-effective model system of the kidney. The unique advantages of D. melanogaster include ease and low cost of maintenance, comprehensive availability of genetic mutants and powerful transgenic technologies, and less onerous regulation, as compared with mammalian systems. Renal and excretory functions in D. melanogaster reside in three main tissues - the transporting renal (Malpighian) tubules, the reabsorptive hindgut and the endocytic nephrocytes. Tubules contain multiple cell types and regions and generate a primary urine by transcellular transport rather than filtration, which is then subjected to selective reabsorption in the hindgut. By contrast, the nephrocytes are specialized for uptake of macromolecules and equipped with a filtering slit diaphragm resembling that of podocytes. Many genes with key roles in the human kidney have D. melanogaster orthologues that are enriched and functionally relevant in fly renal tissues. This similarity has allowed investigations of epithelial transport, kidney stone formation and podocyte and proximal tubule function. Furthermore, a range of unique quantitative phenotypes are available to measure function in both wild type and disease-modelling flies.
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Affiliation(s)
- Julian A T Dow
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
| | - Matias Simons
- INSERM UMR1163, Laboratory of Epithelial Biology and Disease, Imagine Institute, Université de Paris, Hôpital Necker-Enfants Malades, Paris, France
- Institute of Human Genetics, University Hospital Heidelberg, Heidelberg, Germany
| | - Michael F Romero
- Department of Physiology and Biomedical Engineering, Division of Nephrology and Hypertension, Mayo Clinic College of Medicine and Science, Rochester, MN, USA
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22
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Xu J, Liu Y, Li H, Tarashansky AJ, Kalicki CH, Hung RJ, Hu Y, Comjean A, Kolluru SS, Wang B, Quake SR, Luo L, McMahon AP, Dow JAT, Perrimon N. Transcriptional and functional motifs defining renal function revealed by single-nucleus RNA sequencing. Proc Natl Acad Sci U S A 2022; 119:e2203179119. [PMID: 35696569 PMCID: PMC9231607 DOI: 10.1073/pnas.2203179119] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 05/11/2022] [Indexed: 01/09/2023] Open
Abstract
Recent advances in single-cell sequencing provide a unique opportunity to gain novel insights into the diversity, lineage, and functions of cell types constituting a tissue/organ. Here, we performed a single-nucleus study of the adult Drosophila renal system, consisting of Malpighian tubules and nephrocytes, which shares similarities with the mammalian kidney. We identified 11 distinct clusters representing renal stem cells, stellate cells, regionally specific principal cells, garland nephrocyte cells, and pericardial nephrocytes. Characterization of the transcription factors specific to each cluster identified fruitless (fru) as playing a role in stem cell regeneration and Hepatocyte nuclear factor 4 (Hnf4) in regulating glycogen and triglyceride metabolism. In addition, we identified a number of genes, including Rho guanine nucleotide exchange factor at 64C (RhoGEF64c), Frequenin 2 (Frq2), Prip, and CG1093 that are involved in regulating the unusual star shape of stellate cells. Importantly, the single-nucleus dataset allows visualization of the expression at the organ level of genes involved in ion transport and junctional permeability, providing a systems-level view of the organization and physiological roles of the tubules. Finally, a cross-species analysis allowed us to match the fly kidney cell types to mouse kidney cell types and planarian protonephridia, knowledge that will help the generation of kidney disease models. Altogether, our study provides a comprehensive resource for studying the fly kidney.
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Affiliation(s)
- Jun Xu
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Harvard University, Boston, MA 02115
| | - Yifang Liu
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Harvard University, Boston, MA 02115
| | - Hongjie Li
- Department of Biology, Stanford University, Stanford, CA 94305
- HHMI, Stanford University, Stanford, CA 94305
| | - Alexander J. Tarashansky
- Department of Bioengineering, Stanford University, Stanford, CA 94305
- Chan Zuckerberg Biohub, San Francisco, CA 94158
| | - Colin H. Kalicki
- Department of Bioengineering, Stanford University, Stanford, CA 94305
| | - Ruei-Jiun Hung
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Harvard University, Boston, MA 02115
| | - Yanhui Hu
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Harvard University, Boston, MA 02115
| | - Aram Comjean
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Harvard University, Boston, MA 02115
| | - Sai Saroja Kolluru
- Department of Bioengineering, Stanford University, Stanford, CA 94305
- Chan Zuckerberg Biohub, San Francisco, CA 94158
| | - Bo Wang
- Department of Bioengineering, Stanford University, Stanford, CA 94305
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305
| | - Stephen R. Quake
- Department of Bioengineering, Stanford University, Stanford, CA 94305
- Chan Zuckerberg Biohub, San Francisco, CA 94158
| | - Liqun Luo
- Department of Biology, Stanford University, Stanford, CA 94305
- HHMI, Stanford University, Stanford, CA 94305
| | - Andrew P. McMahon
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089
| | - Julian A. T. Dow
- Institute of Molecular, Cell & Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Norbert Perrimon
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Harvard University, Boston, MA 02115
- HHMI, Harvard University, Boston, MA 02115
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23
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Gerstner L, Chen M, Kampf LL, Milosavljevic J, Lang K, Schneider R, Hildebrandt F, Helmstädter M, Walz G, Hermle T. Inhibition of endoplasmic reticulum stress signaling rescues cytotoxicity of human apolipoprotein-L1 risk variants in Drosophila. Kidney Int 2022; 101:1216-1231. [PMID: 35120995 PMCID: PMC10061223 DOI: 10.1016/j.kint.2021.12.031] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Revised: 12/10/2021] [Accepted: 12/23/2021] [Indexed: 01/01/2023]
Abstract
Risk variants of the apolipoprotein-L1 (APOL1) gene are associated with severe kidney disease, putting homozygous carriers at risk. Since APOL1 lacks orthologs in all major model organisms, a wide range of mechanisms frequently in conflict have been described for APOL1-associated nephropathies. The genetic toolkit in Drosophila allows unique in vivo insights into disrupted cellular homeostasis. To perform a mechanistic analysis, we expressed human APOL1 control and gain-of-function kidney risk variants in the podocyte-like garland cells of Drosophila nephrocytes and a wing precursor tissue. Expression of APOL1 risk variants was found to elevate endocytic function of garland cell nephrocytes that simultaneously showed early signs of cell death. Wild-type APOL1 had a significantly milder effect, while a control transgene with deletion of the short BH3 domain showed no overt phenotype. Nephrocyte endo-lysosomal function and slit diaphragm architecture remained unaffected by APOL1 risk variants, but endoplasmic reticulum (ER) swelling, chaperone induction, and expression of the reporter Xbp1-EGFP suggested an ER stress response. Pharmacological inhibition of ER stress diminished APOL1-mediated cell death and direct ER stress induction enhanced nephrocyte endocytic function similar to expression of APOL1 risk variants. We confirmed APOL1-dependent ER stress in the Drosophila wing precursor where silencing the IRE1-dependent branch of ER stress signaling by inhibition with Xbp1-RNAi abrogated cell death, representing the first rescue of APOL1-associated cytotoxicity in vivo. Thus, we uncovered ER stress as an essential consequence of APOL1 risk variant expression in vivo in Drosophila, suggesting a central role of this pathway in the pathogenesis of APOL1-associated nephropathies.
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Affiliation(s)
- Lea Gerstner
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center-University of Freiburg, Freiburg, Germany
| | - Mengmeng Chen
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center-University of Freiburg, Freiburg, Germany
| | - Lina L Kampf
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center-University of Freiburg, Freiburg, Germany
| | - Julian Milosavljevic
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center-University of Freiburg, Freiburg, Germany
| | - Konrad Lang
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center-University of Freiburg, Freiburg, Germany
| | - Ronen Schneider
- Renal Division, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Friedhelm Hildebrandt
- Renal Division, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Martin Helmstädter
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center-University of Freiburg, Freiburg, Germany
| | - Gerd Walz
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center-University of Freiburg, Freiburg, Germany; Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
| | - Tobias Hermle
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center-University of Freiburg, Freiburg, Germany.
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24
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Mechanisms and Therapeutic Effects of Benzoquinone Ring Analogs in Primary CoQ Deficiencies. Antioxidants (Basel) 2022; 11:antiox11040665. [PMID: 35453349 PMCID: PMC9029335 DOI: 10.3390/antiox11040665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 03/26/2022] [Accepted: 03/28/2022] [Indexed: 11/16/2022] Open
Abstract
Coenzyme Q (CoQ) is a conserved polyprenylated lipid composed of a redox-active benzoquinone ring and a long polyisoprenyl tail that serves as a membrane anchor. CoQ biosynthesis involves multiple steps, including multiple modifications of the precursor ring 4-hydroxybenzoic acid. Mutations in the enzymes involved in CoQ biosynthesis pathway result in primary coenzyme Q deficiencies, mitochondrial disorders whose clinical heterogenicity reflects the multiple biological function of CoQ. Patients with these disorders do not always respond to CoQ supplementation, and CoQ analogs have not been successful as alternative approaches. Progress made in understanding the CoQ biosynthesis pathway and studies of supplementation with 4-hydroxybenzoic acid ring analogs have opened a new area in the field of primary CoQ deficiencies treatment. Here, we will review these studies, focusing on efficacy of the different 4-hydroxybenzoic acid ring analogs, models in which they have been tested, and their mechanisms of action. Understanding how these compounds ameliorate biochemical, molecular, and/or clinical phenotypes of CoQ deficiencies is important to develop the most rational treatment for CoQ deficient patients, depending on their molecular defects.
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25
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Maywald ML, Picciotto C, Lepa C, Bertgen L, Yousaf FS, Ricker A, Klingauf J, Krahn MP, Pavenstädt H, George B. Rap1 Activity Is Essential for Focal Adhesion and Slit Diaphragm Integrity. Front Cell Dev Biol 2022; 10:790365. [PMID: 35372328 PMCID: PMC8972170 DOI: 10.3389/fcell.2022.790365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 02/24/2022] [Indexed: 11/24/2022] Open
Abstract
Glomerular podocytes build, with their intercellular junctions, part of the kidney filter. The podocyte cell adhesion protein, nephrin, is essential for developing and maintaining slit diaphragms as functional loss in humans results in heavy proteinuria. Nephrin expression and function are also altered in many adult-onset glomerulopathies. Nephrin signals from the slit diaphragm to the actin cytoskeleton and integrin β1 at focal adhesions by recruiting Crk family proteins, which can interact with the Rap guanine nucleotide exchange factor 1 C3G. As Rap1 activity affects focal adhesion formation, we hypothesize that nephrin signals via Rap1 to integrin β. To address this issue, we combined Drosophila in vivo and mammalian cell culture experiments. We find that Rap1 is necessary for correct targeting of integrin β to focal adhesions in Drosophila nephrocytes, which also form slit diaphragm-like structures. In the fly, the Rap1 activity is important for signaling of the nephrin ortholog to integrin β, as well as for nephrin-dependent slit diaphragm integrity. We show by genetic interaction experiments that Rap1 functions downstream of nephrin signaling to integrin β and downstream of nephrin signaling necessary for slit diaphragm integrity. Similarly, in human podocyte culture, nephrin activation results in increased activation of Rap1. Thus, Rap1 is necessary for downstream signal transduction of nephrin to integrin β.
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Affiliation(s)
- Mee-Ling Maywald
- Medizinische Klinik D, University Hospital Münster, Münster, Germany
| | - Cara Picciotto
- Medizinische Klinik D, University Hospital Münster, Münster, Germany
| | - Carolin Lepa
- Medizinische Klinik D, University Hospital Münster, Münster, Germany
| | - Luisa Bertgen
- Medizinische Klinik D, University Hospital Münster, Münster, Germany
| | | | - Andrea Ricker
- Institute of Medical Physics and Biophysics, Westfälische Wilhelms-University Münster, Münster, Germany
| | - Jürgen Klingauf
- Institute of Medical Physics and Biophysics, Westfälische Wilhelms-University Münster, Münster, Germany
| | - Michael P. Krahn
- Medizinische Klinik D, Medical Cell Biology, University Hospital Münster, Münster, Germany
| | | | - Britta George
- Medizinische Klinik D, University Hospital Münster, Münster, Germany
- *Correspondence: Britta George,
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26
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Kozyraki R, Verroust P, Cases O. Cubilin, the intrinsic factor-vitamin B12 receptor. VITAMINS AND HORMONES 2022; 119:65-119. [PMID: 35337634 DOI: 10.1016/bs.vh.2022.01.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Cubilin (CUBN), the intrinsic factor-vitamin B12 receptor is a large endocytic protein involved in various physiological functions: vitamin B12 uptake in the gut; reabsorption of albumin and maturation of vitamin D in the kidney; nutrient delivery during embryonic development. Cubilin is an atypical receptor, peripherally associated to the plasma membrane. The transmembrane proteins amnionless (AMN) and Lrp2/Megalin are the currently known molecular partners contributing to plasma membrane transport and internalization of Cubilin. The role of Cubilin/Amn complex in the handling of vitamin B12 in health and disease has extensively been studied and so is the role of the Cubilin-Lrp2 tandem in renal pathophysiology. Accumulating evidence strongly supports a role of Cubilin in some developmental defects including impaired closure of the neural tube. Are these defects primarily caused by the dysfunction of a specific Cubilin ligand or are they secondary to impaired vitamin B12 or protein uptake? We will present the established Cubilin functions, discuss the developmental data and provide an overview of the emerging implications of Cubilin in the field of cardiovascular disease and cancer pathogenesis.
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Affiliation(s)
- Renata Kozyraki
- Centre de Recherche des Cordeliers, Sorbonne Université, INSERM, Université de Paris, Paris, France.
| | - Pierre Verroust
- Centre de Recherche des Cordeliers, Sorbonne Université, INSERM, Université de Paris, Paris, France
| | - Olivier Cases
- Centre de Recherche des Cordeliers, Sorbonne Université, INSERM, Université de Paris, Paris, France
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27
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van de Leemput J, Wen P, Han Z. Using Drosophila Nephrocytes to Understand the Formation and Maintenance of the Podocyte Slit Diaphragm. Front Cell Dev Biol 2022; 10:837828. [PMID: 35265622 PMCID: PMC8898902 DOI: 10.3389/fcell.2022.837828] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 02/01/2022] [Indexed: 12/12/2022] Open
Abstract
The podocyte slit diaphragm (SD) is an essential component of the glomerular filtration barrier and its disruption is a common cause of proteinuria and many types of kidney disease. Therefore, better understanding of the pathways and proteins that play key roles in SD formation and maintenance has been of great interest. Podocyte and SD biology have been mainly studied using mouse and other vertebrate models. However, vertebrates are limited by inherent properties and technically challenging in vivo access to the podocytes. Drosophila is a relatively new alternative model system but it has already made great strides. Past the initial obvious differences, mammalian podocytes and fly nephrocytes are remarkably similar at the genetic, molecular and functional levels. This review discusses SD formation and maintenance, and their dependence on cell polarity, the cytoskeleton, and endo- and exocytosis, as learned from studies in fly nephrocytes and mammalian podocytes. In addition, it reflects on the remaining gaps in our knowledge, the physiological implications for glomerular diseases and how we can leverage the advantages Drosophila has to offer to further our understanding.
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Affiliation(s)
- Joyce van de Leemput
- Center for Precision Disease Modeling, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Pei Wen
- Center for Precision Disease Modeling, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Zhe Han
- Center for Precision Disease Modeling, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
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28
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Krause SA, Overend G, Dow JAT, Leader DP. FlyAtlas 2 in 2022: enhancements to the Drosophila melanogaster expression atlas. Nucleic Acids Res 2022; 50:D1010-D1015. [PMID: 34718735 PMCID: PMC8728208 DOI: 10.1093/nar/gkab971] [Citation(s) in RCA: 41] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 10/03/2021] [Accepted: 10/07/2021] [Indexed: 01/12/2023] Open
Abstract
FlyAtlas 2 (flyatlas2.org) is a database and web application for studying the expression of the genes of Drosophila melanogaster in different tissues of adults and larvae. It is based on RNA-Seq data, and incorporates both genes encoding proteins and microRNAs. We have now completed the population of the database with 13 tissues from both male and female adults, five sex-specific tissues, and eight larval tissues. Larval garland cell nephrocytes have also been included. Major enhancements have been made to the application. First, a facility has been added for a 'Profile' search for genes with a similar pattern of tissue expression as a query gene. This may help establish the function of genes for which this is currently unknown. Second, a facility has been added dedicated to the larval midgut, where the difference in gene expression in the five regions of different pH can be explored. A variety of further improvements to the interface are described.
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Affiliation(s)
- Sue A Krause
- Institute of Molecular, Cell & Systems Biology, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Gayle Overend
- Institute of Molecular, Cell & Systems Biology, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Julian A T Dow
- Institute of Molecular, Cell & Systems Biology, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - David P Leader
- Institute of Molecular, Cell & Systems Biology, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
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29
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Koehler S, Odenthal J, Ludwig V, Jess DU, Höhne M, Jüngst C, Grawe F, Helmstädter M, Janku JL, Bergmann C, Hoyer PF, Hagmann HHH, Walz G, Bloch W, Niessen C, Schermer B, Wodarz A, Denholm B, Benzing T, Iden S, Brinkkoetter PT. Scaffold polarity proteins Par3A and Par3B share redundant functions while Par3B acts independent of atypical protein kinase C/Par6 in podocytes to maintain the kidney filtration barrier. Kidney Int 2021; 101:733-751. [PMID: 34929254 DOI: 10.1016/j.kint.2021.11.030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 11/08/2021] [Accepted: 11/22/2021] [Indexed: 10/19/2022]
Abstract
Glomerular diseases are a major cause for chronic kidney disorders. In most cases podocyte injury is causative for disease development. Cytoskeletal rearrangements and morphological changes are hallmark features of podocyte injury and result in dedifferentiation and loss of podocytes. Here, we establish a link between the Par3 polarity complex and actin regulators necessary to establish and maintain podocyte architecture by utilizing mouse and Drosophila models to characterize the functional role of Par3A and Par3B and its fly homologue Bazooka in vivo. Only simultaneous inactivation of both Par3 proteins caused a severe disease phenotype. Rescue experiments in Drosophila nephrocytes revealed atypical protein kinase C (aPKC)-Par6 dependent and independent effects. While Par3A primarily acts via aPKC-Par6, Par3B function was independent of Par6. Actin-associated synaptopodin protein levels were found to be significantly upregulated upon loss of Par3A/B in mouse podocytes. Tropomyosin2, which shares functional similarities with synaptopodin, was also elevated in Bazooka depleted nephrocytes. The simultaneous depletion of Bazooka and Tropomyosin2 resulted in a partial rescue of the Bazooka knockdown phenotype and prevented increased Rho1, a member of a GTPase protein family regulating the cytoskeleton. The latter contribute to the nephrocyte phenotype observed upon loss of Bazooka. Thus, we demonstrate that Par3 proteins share a high functional redundancy but also have specific functions. Par3A acts in an aPKC-Par6 dependent way and regulates RhoA-GTP levels, while Par3B exploits Par6 independent functions influencing synaptopodin localization. Hence, Par3A and Par3B link elements of polarity signaling and actin regulators to maintain podocyte architecture.
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Affiliation(s)
- Sybille Koehler
- Department II of Internal Medicine; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Biomedical Sciences, University of Edinburgh, Edinburgh, Scotland, UK.
| | - Johanna Odenthal
- Department II of Internal Medicine; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Vivian Ludwig
- Department II of Internal Medicine; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - David Unnersjö Jess
- Department II of Internal Medicine; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Martin Höhne
- Department II of Internal Medicine; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Christian Jüngst
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Ferdi Grawe
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany; Molecular Cell Biology, Institute I for Anatomy, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Martin Helmstädter
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Johanna L Janku
- Department II of Internal Medicine; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Carsten Bergmann
- Medizinische Genetik Mainz, Limbach Genetics, Mainz, Germany; Department of Medicine, Nephrology, University Hospital Freiburg, Germany
| | - Peter F Hoyer
- Klinik für Kinderheilkunde 2, Zentrum für Kinder- und Jugendmedizin, Universitätsklinikum Essen, Essen, Germany
| | - H H Henning Hagmann
- Department II of Internal Medicine; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Gerd Walz
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Wilhelm Bloch
- Department of Molecular and Cellular Sport Medicine, Institute of Cardiovascular Research and Sport Medicine, German Sport University Cologne, Cologne, Germany
| | - Carien Niessen
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany; Department of Dermatology, University Hospital of Cologne, Cologne, Germany
| | - Bernhard Schermer
- Department II of Internal Medicine; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Andreas Wodarz
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany; Molecular Cell Biology, Institute I for Anatomy, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Barry Denholm
- Biomedical Sciences, University of Edinburgh, Edinburgh, Scotland, UK
| | - Thomas Benzing
- Department II of Internal Medicine; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Sandra Iden
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany; Institute for Cell and Developmental Biology, Saarland University, Homburg/Saar, Germany
| | - Paul T Brinkkoetter
- Department II of Internal Medicine; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany.
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Atienza-Manuel A, Castillo-Mancho V, De Renzis S, Culi J, Ruiz-Gómez M. Endocytosis mediated by an atypical CUBAM complex modulates slit diaphragm dynamics in nephrocytes. Development 2021; 148:272711. [PMID: 34738617 PMCID: PMC8710305 DOI: 10.1242/dev.199894] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 10/22/2021] [Indexed: 01/14/2023]
Abstract
The vertebrate endocytic receptor CUBAM, consisting of three cubilin monomers complexed with a single amnionless molecule, plays a major role in protein reabsorption in the renal proximal tubule. Here, we show that Drosophila CUBAM is a tripartite complex composed of Amnionless and two cubilin paralogues, Cubilin and Cubilin2, and that it is required for nephrocyte slit diaphragm (SD) dynamics. Loss of CUBAM-mediated endocytosis induces dramatic morphological changes in nephrocytes and promotes enlarged ingressions of the external membrane and SD mislocalisation. These phenotypes result in part from an imbalance between endocytosis, which is strongly impaired in CUBAM mutants, and exocytosis in these highly active cells. Of note, rescuing receptor-mediated endocytosis by Megalin/LRP2 or Rab5 expression only partially restores SD positioning in CUBAM mutants, suggesting a specific requirement of CUBAM in SD degradation and/or recycling. This finding and the reported expression of CUBAM in podocytes suggest a possible unexpected conserved role for this endocytic receptor in vertebrate SD remodelling. Summary: A genetic study revealing that endocytosis mediated by an atypical CUBAM endocytic receptor, composed of Amnionless and two Cubilin paralogues, regulates slit diaphragm remodelling in Drosophila nephrocytes.
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Affiliation(s)
- Alexandra Atienza-Manuel
- Centro de Biología Molecular Severo Ochoa, CSIC and UAM, Nicolás Cabrera 1, Cantoblanco 28049, Madrid, Spain
| | - Vicente Castillo-Mancho
- Centro de Biología Molecular Severo Ochoa, CSIC and UAM, Nicolás Cabrera 1, Cantoblanco 28049, Madrid, Spain
| | - Stefano De Renzis
- European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Joaquim Culi
- Centro de Biología Molecular Severo Ochoa, CSIC and UAM, Nicolás Cabrera 1, Cantoblanco 28049, Madrid, Spain
| | - Mar Ruiz-Gómez
- Centro de Biología Molecular Severo Ochoa, CSIC and UAM, Nicolás Cabrera 1, Cantoblanco 28049, Madrid, Spain
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Primary coenzyme Q10 nephropathy, a potentially treatable form of steroid-resistant nephrotic syndrome. Pediatr Nephrol 2021; 36:3515-3527. [PMID: 33479824 PMCID: PMC8295399 DOI: 10.1007/s00467-020-04914-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 11/28/2020] [Accepted: 12/31/2020] [Indexed: 12/18/2022]
Abstract
Steroid-resistant nephrotic syndrome (SRNS) is a genetically heterogeneous kidney disease that is the second most frequent cause of kidney failure in the first 2 decades of life. Despite the identification of mutations in more than 39 genes as causing SRNS, and the localization of its pathogenesis to glomerular podocytes, the disease mechanisms of SRNS remain poorly understood and no universally safe and effective therapy exists to treat patients with this condition. Recently, genetic research has identified a subgroup of SRNS patients whose kidney pathology is caused by primary coenzyme Q10 (CoQ10) deficiency due to recessive mutations in genes that encode proteins in the CoQ10 biosynthesis pathway. Clinical and preclinical studies show that primary CoQ10 deficiency may be responsive to treatment with CoQ10 supplements bypassing the biosynthesis defects. Coenzyme Q10 is an essential component of the mitochondrial respiratory chain, where it transports electrons from complexes I and II to complex III. Studies in yeast and mammalian model systems have recently identified the molecular functions of the individual CoQ10 biosynthesis complex proteins, validated these findings, and provided an impetus for developing therapeutic compounds to replenish CoQ10 levels in the tissues/organs and thus prevent the destruction of tissues due to mitochondrial OXPHOS deficiencies. In this review, we will summarize the clinical findings of the kidney pathophysiology of primary CoQ10 deficiencies and discuss recent advances in the development of therapies to counter CoQ10 deficiency in tissues.
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González-García P, Barriocanal-Casado E, Díaz-Casado ME, López-Herrador S, Hidalgo-Gutiérrez A, López LC. Animal Models of Coenzyme Q Deficiency: Mechanistic and Translational Learnings. Antioxidants (Basel) 2021; 10:antiox10111687. [PMID: 34829558 PMCID: PMC8614664 DOI: 10.3390/antiox10111687] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 10/21/2021] [Accepted: 10/23/2021] [Indexed: 12/16/2022] Open
Abstract
Coenzyme Q (CoQ) is a vital lipophilic molecule that is endogenously synthesized in the mitochondria of each cell. The CoQ biosynthetic pathway is complex and not completely characterized, and it involves at least thirteen catalytic and regulatory proteins. Once it is synthesized, CoQ exerts a wide variety of mitochondrial and extramitochondrial functions thank to its redox capacity and its lipophilicity. Thus, low levels of CoQ cause diseases with heterogeneous clinical symptoms, which are not always understood. The decreased levels of CoQ may be primary caused by defects in the CoQ biosynthetic pathway or secondarily associated with other diseases. In both cases, the pathomechanisms are related to the CoQ functions, although further experimental evidence is required to establish this association. The conventional treatment for CoQ deficiencies is the high doses of oral CoQ10 supplementation, but this therapy is not effective for some specific clinical presentations, especially in those involving the nervous system. To better understand the CoQ biosynthetic pathway, the biological functions linked to CoQ and the pathomechanisms of CoQ deficiencies, and to improve the therapeutic outcomes of this syndrome, a variety of animal models have been generated and characterized in the last decade. In this review, we show all the animal models available, remarking on the most important outcomes that each model has provided. Finally, we also comment some gaps and future research directions related to CoQ metabolism and how the current and novel animal models may help in the development of future research studies.
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Affiliation(s)
- Pilar González-García
- Departamento de Fisiología, Facultad de Medicina, Universidad de Granada, 18016 Granada, Spain; (E.B.-C.); (M.E.D.-C.); (S.L.-H.); (A.H.-G.)
- Centro de Investigación Biomédica, Instituto de Biotecnología, Universidad de Granada, 18016 Granada, Spain
- Correspondence: (P.G.-G.); (L.C.L.)
| | - Eliana Barriocanal-Casado
- Departamento de Fisiología, Facultad de Medicina, Universidad de Granada, 18016 Granada, Spain; (E.B.-C.); (M.E.D.-C.); (S.L.-H.); (A.H.-G.)
- Centro de Investigación Biomédica, Instituto de Biotecnología, Universidad de Granada, 18016 Granada, Spain
| | - María Elena Díaz-Casado
- Departamento de Fisiología, Facultad de Medicina, Universidad de Granada, 18016 Granada, Spain; (E.B.-C.); (M.E.D.-C.); (S.L.-H.); (A.H.-G.)
- Centro de Investigación Biomédica, Instituto de Biotecnología, Universidad de Granada, 18016 Granada, Spain
| | - Sergio López-Herrador
- Departamento de Fisiología, Facultad de Medicina, Universidad de Granada, 18016 Granada, Spain; (E.B.-C.); (M.E.D.-C.); (S.L.-H.); (A.H.-G.)
- Centro de Investigación Biomédica, Instituto de Biotecnología, Universidad de Granada, 18016 Granada, Spain
| | - Agustín Hidalgo-Gutiérrez
- Departamento de Fisiología, Facultad de Medicina, Universidad de Granada, 18016 Granada, Spain; (E.B.-C.); (M.E.D.-C.); (S.L.-H.); (A.H.-G.)
- Centro de Investigación Biomédica, Instituto de Biotecnología, Universidad de Granada, 18016 Granada, Spain
| | - Luis C. López
- Departamento de Fisiología, Facultad de Medicina, Universidad de Granada, 18016 Granada, Spain; (E.B.-C.); (M.E.D.-C.); (S.L.-H.); (A.H.-G.)
- Centro de Investigación Biomédica, Instituto de Biotecnología, Universidad de Granada, 18016 Granada, Spain
- Correspondence: (P.G.-G.); (L.C.L.)
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33
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Cellular Models for Primary CoQ Deficiency Pathogenesis Study. Int J Mol Sci 2021; 22:ijms221910211. [PMID: 34638552 PMCID: PMC8508219 DOI: 10.3390/ijms221910211] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 09/17/2021] [Accepted: 09/18/2021] [Indexed: 02/07/2023] Open
Abstract
Primary coenzyme Q10 (CoQ) deficiency includes a heterogeneous group of mitochondrial diseases characterized by low mitochondrial levels of CoQ due to decreased endogenous biosynthesis rate. These diseases respond to CoQ treatment mainly at the early stages of the disease. The advances in the next generation sequencing (NGS) as whole-exome sequencing (WES) and whole-genome sequencing (WGS) have increased the discoveries of mutations in either gene already described to participate in CoQ biosynthesis or new genes also involved in this pathway. However, these technologies usually provide many mutations in genes whose pathogenic effect must be validated. To functionally validate the impact of gene variations in the disease’s onset and progression, different cell models are commonly used. We review here the use of yeast strains for functional complementation of human genes, dermal skin fibroblasts from patients as an excellent tool to demonstrate the biochemical and genetic mechanisms of these diseases and the development of human-induced pluripotent stem cells (hiPSCs) and iPSC-derived organoids for the study of the pathogenesis and treatment approaches.
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34
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Solanki AK, Arif E, Srivastava P, Furcht CM, Rahman B, Wen P, Singh A, Holzman LB, Fitzgibbon WR, Budisavljevic MN, Lobo GP, Kwon SH, Han Z, Lazzara MJ, Lipschutz JH, Nihalani D. Phosphorylation of slit diaphragm proteins NEPHRIN and NEPH1 upon binding of HGF promotes podocyte repair. J Biol Chem 2021; 297:101079. [PMID: 34391780 PMCID: PMC8429977 DOI: 10.1016/j.jbc.2021.101079] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 08/02/2021] [Accepted: 08/11/2021] [Indexed: 12/22/2022] Open
Abstract
Phosphorylation (activation) and dephosphorylation (deactivation) of the slit diaphragm proteins NEPHRIN and NEPH1 are critical for maintaining the kidney epithelial podocyte actin cytoskeleton and, therefore, proper glomerular filtration. However, the mechanisms underlying these events remain largely unknown. Here we show that NEPHRIN and NEPH1 are novel receptor proteins for hepatocyte growth factor (HGF) and can be phosphorylated independently of the mesenchymal epithelial transition receptor in a ligand-dependent fashion through engagement of their extracellular domains by HGF. Furthermore, we demonstrate SH2 domain–containing protein tyrosine phosphatase-2–dependent dephosphorylation of these proteins. To establish HGF as a ligand, purified baculovirus-expressed NEPHRIN and NEPH1 recombinant proteins were used in surface plasma resonance binding experiments. We report high-affinity interactions of NEPHRIN and NEPH1 with HGF, although NEPHRIN binding was 20-fold higher than that of NEPH1. In addition, using molecular modeling we constructed peptides that were used to map specific HGF-binding regions in the extracellular domains of NEPHRIN and NEPH1. Finally, using an in vitro model of cultured podocytes and an ex vivo model of Drosophila nephrocytes, as well as chemically induced injury models, we demonstrated that HGF-induced phosphorylation of NEPHRIN and NEPH1 is centrally involved in podocyte repair. Taken together, this is the first study demonstrating a receptor-based function for NEPHRIN and NEPH1. This has important biological and clinical implications for the repair of injured podocytes and the maintenance of podocyte integrity.
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Affiliation(s)
- Ashish K Solanki
- Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Ehtesham Arif
- Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Pankaj Srivastava
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Christopher M Furcht
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Bushra Rahman
- Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Pei Wen
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Avinash Singh
- Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Lawrence B Holzman
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Wayne R Fitzgibbon
- Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Milos N Budisavljevic
- Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Glenn P Lobo
- Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Sang-Ho Kwon
- Department of Cellular Biology and Anatomy, Augusta University, Augusta, Georgia, USA
| | - Zhe Han
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Matthew J Lazzara
- Department of Chemical Engineering, University of Virginia, Charlottesville, Virginia, USA
| | - Joshua H Lipschutz
- Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, USA; Department of Medicine, Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina, USA.
| | - Deepak Nihalani
- Division of Kidney, Urologic and Hematologic Diseases, National Institutes of Health, Bethesda, Maryland, USA
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Martinez-Arroyo O, Selma-Soriano E, Ortega A, Cortes R, Redon J. Small Rab GTPases in Intracellular Vesicle Trafficking: The Case of Rab3A/Raphillin-3A Complex in the Kidney. Int J Mol Sci 2021; 22:7679. [PMID: 34299299 PMCID: PMC8303874 DOI: 10.3390/ijms22147679] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 07/09/2021] [Accepted: 07/12/2021] [Indexed: 12/12/2022] Open
Abstract
Small Rab GTPases, the largest group of small monomeric GTPases, regulate vesicle trafficking in cells, which are integral to many cellular processes. Their role in neurological diseases, such as cancer and inflammation have been extensively studied, but their implication in kidney disease has not been researched in depth. Rab3a and its effector Rabphillin-3A (Rph3A) expression have been demonstrated to be present in the podocytes of normal kidneys of mice rats and humans, around vesicles contained in the foot processes, and they are overexpressed in diseases with proteinuria. In addition, the Rab3A knockout mice model induced profound cytoskeletal changes in podocytes of high glucose fed animals. Likewise, RphA interference in the Drosophila model produced structural and functional damage in nephrocytes with reduction in filtration capacities and nephrocyte number. Changes in the structure of cardiac fiber in the same RphA-interference model, open the question if Rab3A dysfunction would produce simultaneous damage in the heart and kidney cells, an attractive field that will require attention in the future.
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Affiliation(s)
- Olga Martinez-Arroyo
- Cardiometabolic and Renal Risk Research Group, INCLIVA Biomedical Research Institute, 46010 Valencia, Spain; (O.M.-A.); (R.C.)
| | - Estela Selma-Soriano
- Physiopathology of Cellular and Organic Oxidative Stress Group, University of Valencia, 46100 Valencia, Spain;
| | - Ana Ortega
- Cardiometabolic and Renal Risk Research Group, INCLIVA Biomedical Research Institute, 46010 Valencia, Spain; (O.M.-A.); (R.C.)
| | - Raquel Cortes
- Cardiometabolic and Renal Risk Research Group, INCLIVA Biomedical Research Institute, 46010 Valencia, Spain; (O.M.-A.); (R.C.)
| | - Josep Redon
- Cardiometabolic and Renal Risk Research Group, INCLIVA Biomedical Research Institute, 46010 Valencia, Spain; (O.M.-A.); (R.C.)
- CIBERObn, Carlos III Institute, 28029 Madrid, Spain
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Mysh M, Poulton JS. The Basolateral Polarity Module Promotes Slit Diaphragm Formation in Drosophila Nephrocytes, a Model of Vertebrate Podocytes. J Am Soc Nephrol 2021; 32:1409-1424. [PMID: 33795424 PMCID: PMC8259641 DOI: 10.1681/asn.2020071050] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 02/12/2021] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Podocyte slit diaphragms (SDs) are intercellular junctions that function as size-selective filters, excluding most proteins from urine. Abnormalities in SDs cause proteinuria and nephrotic syndrome. Podocytes exhibit apicobasal polarity, which can affect fundamental aspects of cell biology, including morphology, intercellular junction formation, and asymmetric protein distribution along the plasma membrane. Apical polarity protein mutations cause nephrotic syndrome, and data suggest apical polarity proteins regulate SD formation. However, there is no evidence that basolateral polarity proteins regulate SDs. Thus, the role of apicobasal polarity in podocytes remains unclear. METHODS Genetic manipulations and transgenic reporters determined the effects of disrupting apicobasal polarity proteins in Drosophila nephrocytes, which have SDs similar to those of mammalian podocytes. Confocal and electron microscopy were used to characterize SD integrity after loss of basolateral polarity proteins, and genetic-interaction studies illuminated relationships among apicobasal polarity proteins. RESULTS The study identified four novel regulators of nephrocyte SDs: Dlg, Lgl, Scrib, and Par-1. These proteins comprise the basolateral polarity module and its effector kinase. The data suggest these proteins work together, with apical polarity proteins, to regulate SDs by promoting normal endocytosis and trafficking of SD proteins. CONCLUSIONS Given the recognized importance of apical polarity proteins and SD protein trafficking in podocytopathies, the findings connecting basolateral polarity proteins to these processes significantly advance our understanding of SD regulation.
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Affiliation(s)
- Michael Mysh
- Department of Biology, UNC Kidney Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - John S. Poulton
- Division of Nephrology and Hypertension, Department of Medicine, UNC Kidney Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
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37
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Wang L, Wen P, van de Leemput J, Zhao Z, Han Z. Slit diaphragm maintenance requires dynamic clathrin-mediated endocytosis facilitated by AP-2, Lap, Aux and Hsc70-4 in nephrocytes. Cell Biosci 2021; 11:83. [PMID: 33975644 PMCID: PMC8111712 DOI: 10.1186/s13578-021-00595-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 04/29/2021] [Indexed: 11/10/2022] Open
Abstract
Background The Slit diaphragm (SD) is the key filtration structure in human glomerular kidney that is affected in many types of renal diseases. SD proteins are known to undergo endocytosis and recycling to maintain the integrity of the filtration structure. However, the key components of this pathway remain unclear. Methods Using the Drosophila nephrocyte as a genetic screen platform, we screened most genes involved in endocytosis and cell trafficking, and identified the key components of the cell trafficking pathway required for SD protein endocytosis and recycling. Results We discovered that the SD protein endocytosis and recycling pathway contains clathrin, dynamin, AP-2 complex, like-AP180 (Lap), auxilin and Hsc70-4 (the endocytosis part) followed by Rab11 and the exocyst complex (the recycling part). Disrupting any component in this pathway led to disrupted SD on the cell surface and intracellular accumulation of mislocalized SD proteins. We also showed the first in vivo evidence of trapped SD proteins in clathrin-coated pits at the plasma membrane when this pathway is disrupted. Conclusions All genes in this SD protein endocytosis and recycling pathway, as well as SD proteins themselves, are highly conserved from flies to humans. Thus, our results suggest that the SD proteins in human kidney undergo the same endocytosis and recycling pathway to maintain the filtration structure, and mutations in any genes in this pathway could lead to abnormal SD and renal diseases. Supplementary Information The online version contains supplementary material available at 10.1186/s13578-021-00595-4.
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Affiliation(s)
- Luyao Wang
- Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe Eastern Road, Zhengzhou, 450052, Henan, China.,Center for Precision Disease Modeling, Department of Medicine, University of Maryland School of Medicine, 670 West Baltimore Street, Baltimore, MD, 21201, USA.,Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Pei Wen
- Center for Precision Disease Modeling, Department of Medicine, University of Maryland School of Medicine, 670 West Baltimore Street, Baltimore, MD, 21201, USA.,Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Joyce van de Leemput
- Center for Precision Disease Modeling, Department of Medicine, University of Maryland School of Medicine, 670 West Baltimore Street, Baltimore, MD, 21201, USA.,Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Zhanzheng Zhao
- Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe Eastern Road, Zhengzhou, 450052, Henan, China.
| | - Zhe Han
- Center for Precision Disease Modeling, Department of Medicine, University of Maryland School of Medicine, 670 West Baltimore Street, Baltimore, MD, 21201, USA. .,Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.
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38
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Lubojemska A, Stefana MI, Sorge S, Bailey AP, Lampe L, Yoshimura A, Burrell A, Collinson L, Gould AP. Adipose triglyceride lipase protects renal cell endocytosis in a Drosophila dietary model of chronic kidney disease. PLoS Biol 2021; 19:e3001230. [PMID: 33945525 PMCID: PMC8121332 DOI: 10.1371/journal.pbio.3001230] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 05/14/2021] [Accepted: 04/13/2021] [Indexed: 12/13/2022] Open
Abstract
Obesity-related renal lipotoxicity and chronic kidney disease (CKD) are prevalent pathologies with complex aetiologies. One hallmark of renal lipotoxicity is the ectopic accumulation of lipid droplets in kidney podocytes and in proximal tubule cells. Renal lipid droplets are observed in human CKD patients and in high-fat diet (HFD) rodent models, but their precise role remains unclear. Here, we establish a HFD model in Drosophila that recapitulates renal lipid droplets and several other aspects of mammalian CKD. Cell type-specific genetic manipulations show that lipid can overflow from adipose tissue and is taken up by renal cells called nephrocytes. A HFD drives nephrocyte lipid uptake via the multiligand receptor Cubilin (Cubn), leading to the ectopic accumulation of lipid droplets. These nephrocyte lipid droplets correlate with endoplasmic reticulum (ER) and mitochondrial deficits, as well as with impaired macromolecular endocytosis, a key conserved function of renal cells. Nephrocyte knockdown of diglyceride acyltransferase 1 (DGAT1), overexpression of adipose triglyceride lipase (ATGL), and epistasis tests together reveal that fatty acid flux through the lipid droplet triglyceride compartment protects the ER, mitochondria, and endocytosis of renal cells. Strikingly, boosting nephrocyte expression of the lipid droplet resident enzyme ATGL is sufficient to rescue HFD-induced defects in renal endocytosis. Moreover, endocytic rescue requires a conserved mitochondrial regulator, peroxisome proliferator-activated receptor-gamma coactivator 1α (PGC1α). This study demonstrates that lipid droplet lipolysis counteracts the harmful effects of a HFD via a mitochondrial pathway that protects renal endocytosis. It also provides a genetic strategy for determining whether lipid droplets in different biological contexts function primarily to release beneficial or to sequester toxic lipids.
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Affiliation(s)
- Aleksandra Lubojemska
- Physiology and Metabolism Laboratory, The Francis Crick Institute, London, United Kingdom
| | - M. Irina Stefana
- Physiology and Metabolism Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Sebastian Sorge
- Physiology and Metabolism Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Andrew P. Bailey
- Physiology and Metabolism Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Lena Lampe
- Physiology and Metabolism Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Azumi Yoshimura
- Electron Microscopy Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Alana Burrell
- Electron Microscopy Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Lucy Collinson
- Electron Microscopy Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Alex P. Gould
- Physiology and Metabolism Laboratory, The Francis Crick Institute, London, United Kingdom
- * E-mail:
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39
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Heiden S, Siwek R, Lotz ML, Borkowsky S, Schröter R, Nedvetsky P, Rohlmann A, Missler M, Krahn MP. Apical-basal polarity regulators are essential for slit diaphragm assembly and endocytosis in Drosophila nephrocytes. Cell Mol Life Sci 2021; 78:3657-3672. [PMID: 33651172 PMCID: PMC8038974 DOI: 10.1007/s00018-021-03769-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 01/11/2021] [Accepted: 01/16/2021] [Indexed: 12/02/2022]
Abstract
Apical-basal polarity is a key feature of most epithelial cells and it is regulated by highly conserved protein complexes. In mammalian podocytes, which emerge from columnar epithelial cells, this polarity is preserved and the tight junctions are converted to the slit diaphragms, establishing the filtration barrier. In Drosophila, nephrocytes show several structural and functional similarities with mammalian podocytes and proximal tubular cells. However, in contrast to podocytes, little is known about the role of apical-basal polarity regulators in these cells. In this study, we used expansion microscopy and found the apical polarity determinants of the PAR/aPKC and Crb-complexes to be predominantly targeted to the cell cortex in proximity to the nephrocyte diaphragm, whereas basolateral regulators also accumulate intracellularly. Knockdown of PAR-complex proteins results in severe endocytosis and nephrocyte diaphragm defects, which is due to impaired aPKC recruitment to the plasma membrane. Similar, downregulation of most basolateral polarity regulators disrupts Nephrin localization but had surprisingly divergent effects on endocytosis. Our findings suggest that morphology and slit diaphragm assembly/maintenance of nephrocytes is regulated by classical apical-basal polarity regulators, which have distinct functions in endocytosis.
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Affiliation(s)
- Stefanie Heiden
- Medical Cell Biology, Medical Clinic D, University Hospital of Münster, Albert-Schweitzer Campus 1-A14, 48149, Münster, Germany
| | - Rebecca Siwek
- Medical Cell Biology, Medical Clinic D, University Hospital of Münster, Albert-Schweitzer Campus 1-A14, 48149, Münster, Germany
| | - Marie-Luise Lotz
- Medical Cell Biology, Medical Clinic D, University Hospital of Münster, Albert-Schweitzer Campus 1-A14, 48149, Münster, Germany
| | - Sarah Borkowsky
- Medical Cell Biology, Medical Clinic D, University Hospital of Münster, Albert-Schweitzer Campus 1-A14, 48149, Münster, Germany
| | - Rita Schröter
- Medical Cell Biology, Medical Clinic D, University Hospital of Münster, Albert-Schweitzer Campus 1-A14, 48149, Münster, Germany
| | - Pavel Nedvetsky
- Medical Cell Biology, Medical Clinic D, University Hospital of Münster, Albert-Schweitzer Campus 1-A14, 48149, Münster, Germany
| | - Astrid Rohlmann
- Institute of Anatomy and Molecular Neurobiology, University of Münster, Vesaliusweg 2-4, 48149, Münster, Germany
| | - Markus Missler
- Institute of Anatomy and Molecular Neurobiology, University of Münster, Vesaliusweg 2-4, 48149, Münster, Germany
| | - Michael P Krahn
- Medical Cell Biology, Medical Clinic D, University Hospital of Münster, Albert-Schweitzer Campus 1-A14, 48149, Münster, Germany.
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40
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Bayraktar S, Nehrig J, Menis E, Karli K, Janning A, Struk T, Halbritter J, Michgehl U, Krahn MP, Schuberth CE, Pavenstädt H, Wedlich-Söldner R. A Deregulated Stress Response Underlies Distinct INF2-Associated Disease Profiles. J Am Soc Nephrol 2021; 31:1296-1313. [PMID: 32444357 DOI: 10.1681/asn.2019111174] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 03/20/2020] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Monogenic diseases provide favorable opportunities to elucidate the molecular mechanisms of disease progression and improve medical diagnostics. However, the complex interplay between genetic and environmental factors in disease etiologies makes it difficult to discern the mechanistic links between different alleles of a single locus and their associated pathophysiologies. Inverted formin 2 (INF2), an actin regulator, mediates a stress response-calcium mediated actin reset, or CaAR-that reorganizes the actin cytoskeleton of mammalian cells in response to calcium influx. It has been linked to the podocytic kidney disease focal segemental glomerulosclerosis (FSGS), as well as to cases of the neurologic disorder Charcot-Marie-Tooth disease that are accompanied by nephropathy, mostly FSGS. METHODS We used a combination of quantitative live cell imaging and validation in primary patient cells and Drosophila nephrocytes to systematically characterize a large panel of >50 autosomal dominant INF2 mutants that have been reported to cause either FSGS alone or with Charcot-Marie-Tooth disease. RESULTS We found that INF2 mutations lead to deregulated activation of formin and a constitutive stress response in cultured cells, primary patient cells, and Drosophila nephrocytes. We were able to clearly distinguish between INF2 mutations that were linked exclusively to FSGS from those that caused a combination of FSGS and Charcot-Marie-Tooth disease. Furthermore, we were able to identify distinct subsets of INF2 variants that exhibit varying degrees of activation. CONCLUSIONS Our results suggest that CaAR can be used as a sensitive assay for INF2 function and for robust evaluation of diseased-linked variants of formin. More broadly, these findings indicate that cellular profiling of disease-associated mutations has potential to contribute substantially to sequence-based phenotype predictions.
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Affiliation(s)
- Samet Bayraktar
- Institute of Cell Dynamics and Imaging and Cells in Motion Interfaculty Centre, University of Münster, Münster, Germany.,Internal Medicine D, University Hospital Münster, Münster, Germany
| | - Julian Nehrig
- Institute of Cell Dynamics and Imaging and Cells in Motion Interfaculty Centre, University of Münster, Münster, Germany
| | - Ekaterina Menis
- Institute of Cell Dynamics and Imaging and Cells in Motion Interfaculty Centre, University of Münster, Münster, Germany
| | - Kevser Karli
- Medical Cell Biology, Internal Medicine D, University Hospital Münster, Münster, Germany
| | - Annette Janning
- Institute of Cell Dynamics and Imaging and Cells in Motion Interfaculty Centre, University of Münster, Münster, Germany
| | - Thaddäus Struk
- Internal Medicine D, University Hospital Münster, Münster, Germany
| | - Jan Halbritter
- Division of Nephrology, University of Leipzig, Leipzig, Germany
| | - Ulf Michgehl
- Internal Medicine D, University Hospital Münster, Münster, Germany
| | - Michael P Krahn
- Medical Cell Biology, Internal Medicine D, University Hospital Münster, Münster, Germany
| | - Christian E Schuberth
- Institute of Cell Dynamics and Imaging and Cells in Motion Interfaculty Centre, University of Münster, Münster, Germany
| | | | - Roland Wedlich-Söldner
- Institute of Cell Dynamics and Imaging and Cells in Motion Interfaculty Centre, University of Münster, Münster, Germany
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41
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Selma-Soriano E, Llamusi B, Fernández-Costa JM, Ozimski LL, Artero R, Redón J. Rabphilin involvement in filtration and molecular uptake in Drosophila nephrocytes suggests a similar role in human podocytes. Dis Model Mech 2020; 13:dmm041509. [PMID: 32680845 PMCID: PMC7522021 DOI: 10.1242/dmm.041509] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 07/07/2020] [Indexed: 02/04/2023] Open
Abstract
Drosophila nephrocytes share functional, structural and molecular similarities with human podocytes. It is known that podocytes express the rabphilin 3A (RPH3A)-RAB3A complex, and its expression is altered in mouse and human proteinuric disease. Furthermore, we previously identified a polymorphism that suggested a role for RPH3A protein in the development of urinary albumin excretion. As endocytosis and vesicle trafficking are fundamental pathways for nephrocytes, the objective of this study was to assess the role of the RPH3A orthologue in Drosophila, Rabphilin (Rph), in the structure and function of nephrocytes. We confirmed that Rph is required for the correct function of the endocytic pathway in pericardial Drosophila nephrocytes. Knockdown of Rph reduced the expression of the cubilin and stick and stones genes, which encode proteins that are involved in protein uptake and filtration. We also found that reduced Rph expression resulted in a disappearance of the labyrinthine channel structure and a reduction in the number of endosomes, which ultimately leads to changes in the number and volume of nephrocytes. Finally, we demonstrated that the administration of retinoic acid to IR-Rph nephrocytes rescued some altered aspects, such as filtration and molecular uptake, as well as the maintenance of cell fate. According to our data, Rph is crucial for nephrocyte filtration and reabsorption, and it is required for the maintenance of the ultrastructure, integrity and differentiation of the nephrocyte.
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Affiliation(s)
- Estela Selma-Soriano
- Translational Genomics Group, Incliva Health Research Institute, 46010 Valencia, Spain
- Interdisciplinary Research Structure for Biotechnology and Biomedicine (ERI BIOTECMED), University of Valencia, 46100 Valencia, Spain
- CIPF-INCLIVA Joint Unit, 46010 Valencia, Spain
| | - Beatriz Llamusi
- Translational Genomics Group, Incliva Health Research Institute, 46010 Valencia, Spain
- Interdisciplinary Research Structure for Biotechnology and Biomedicine (ERI BIOTECMED), University of Valencia, 46100 Valencia, Spain
- CIPF-INCLIVA Joint Unit, 46010 Valencia, Spain
| | - Juan Manuel Fernández-Costa
- Translational Genomics Group, Incliva Health Research Institute, 46010 Valencia, Spain
- Interdisciplinary Research Structure for Biotechnology and Biomedicine (ERI BIOTECMED), University of Valencia, 46100 Valencia, Spain
- CIPF-INCLIVA Joint Unit, 46010 Valencia, Spain
| | - Lauren Louise Ozimski
- Translational Genomics Group, Incliva Health Research Institute, 46010 Valencia, Spain
- Interdisciplinary Research Structure for Biotechnology and Biomedicine (ERI BIOTECMED), University of Valencia, 46100 Valencia, Spain
- CIPF-INCLIVA Joint Unit, 46010 Valencia, Spain
| | - Rubén Artero
- Translational Genomics Group, Incliva Health Research Institute, 46010 Valencia, Spain
- Interdisciplinary Research Structure for Biotechnology and Biomedicine (ERI BIOTECMED), University of Valencia, 46100 Valencia, Spain
- CIPF-INCLIVA Joint Unit, 46010 Valencia, Spain
| | - Josep Redón
- Hypertension Unit, Hospital Clínico Universitario, 46010 Valencia, Spain
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42
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Dehnen L, Janz M, Verma JK, Psathaki OE, Langemeyer L, Fröhlich F, Heinisch JJ, Meyer H, Ungermann C, Paululat A. A trimeric metazoan Rab7 GEF complex is crucial for endocytosis and scavenger function. J Cell Sci 2020; 133:jcs247080. [PMID: 32499409 DOI: 10.1242/jcs.247080] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 05/20/2020] [Indexed: 12/12/2022] Open
Abstract
Endosome biogenesis in eukaryotic cells is critical for nutrient uptake and plasma membrane integrity. Early endosomes initially contain Rab5, which is replaced by Rab7 on late endosomes prior to their fusion with lysosomes. Recruitment of Rab7 to endosomes requires the Mon1-Ccz1 guanine-nucleotide-exchange factor (GEF). Here, we show that full function of the Drosophila Mon1-Ccz1 complex requires a third stoichiometric subunit, termed Bulli (encoded by CG8270). Bulli localises to Rab7-positive endosomes, in agreement with its function in the GEF complex. Using Drosophila nephrocytes as a model system, we observe that absence of Bulli results in (i) reduced endocytosis, (ii) Rab5 accumulation within non-acidified enlarged endosomes, (iii) defective Rab7 localisation and (iv) impaired endosomal maturation. Moreover, longevity of animals lacking bulli is affected. Both the Mon1-Ccz1 dimer and a Bulli-containing trimer display Rab7 GEF activity. In summary, this suggests a key role for Bulli in the Rab5 to Rab7 transition during endosomal maturation rather than a direct influence on the GEF activity of Mon1-Ccz1.
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Affiliation(s)
- Lena Dehnen
- Department of Biology and Chemistry, Zoology and Developmental Biology, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany
| | - Maren Janz
- Department of Biology and Chemistry, Zoology and Developmental Biology, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany
| | - Jitender Kumar Verma
- Department of Biology and Chemistry, Biochemistry, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany
| | - Olympia Ekaterini Psathaki
- Center of Cellular Nanoanalytics, Integrated Bioimaging Facility Osnabrück (iBiOs), University of Osnabrück, 49076 Osnabrück, Germany
| | - Lars Langemeyer
- Department of Biology and Chemistry, Biochemistry, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany
| | - Florian Fröhlich
- Department of Biology and Chemistry, Molecular Membrane Biology, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany
| | - Jürgen J Heinisch
- Department of Biology and Chemistry, Genetics, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany
- Center of Cellular Nanoanalytics, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany
| | - Heiko Meyer
- Department of Biology and Chemistry, Zoology and Developmental Biology, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany
- Center of Cellular Nanoanalytics, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany
| | - Christian Ungermann
- Department of Biology and Chemistry, Biochemistry, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany
- Center of Cellular Nanoanalytics, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany
| | - Achim Paululat
- Department of Biology and Chemistry, Zoology and Developmental Biology, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany
- Center of Cellular Nanoanalytics, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany
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43
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Molinari E, Sayer JA. Disease Modeling To Understand the Pathomechanisms of Human Genetic Kidney Disorders. Clin J Am Soc Nephrol 2020; 15:855-872. [PMID: 32139361 PMCID: PMC7274277 DOI: 10.2215/cjn.08890719] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The class of human genetic kidney diseases is extremely broad and heterogeneous. Accordingly, the range of associated disease phenotypes is highly variable. Many children and adults affected by inherited kidney disease will progress to ESKD at some point in life. Extensive research has been performed on various different disease models to investigate the underlying causes of genetic kidney disease and to identify disease mechanisms that are amenable to therapy. We review some of the research highlights that, by modeling inherited kidney disease, contributed to a better understanding of the underlying pathomechanisms, leading to the identification of novel genetic causes, new therapeutic targets, and to the development of new treatments. We also discuss how the implementation of more efficient genome-editing techniques and tissue-culture methods for kidney research is providing us with personalized models for a precision-medicine approach that takes into account the specificities of the patient and the underlying disease. We focus on the most common model systems used in kidney research and discuss how, according to their specific features, they can differentially contribute to biomedical research. Unfortunately, no definitive treatment exists for most inherited kidney disorders, warranting further exploitation of the existing disease models, as well as the implementation of novel, complex, human patient-specific models to deliver research breakthroughs.
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Affiliation(s)
- Elisa Molinari
- Faculty of Medical Sciences, Translational and Clinical Research Institute, International Centre for Life, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - John A. Sayer
- Faculty of Medical Sciences, Translational and Clinical Research Institute, International Centre for Life, Newcastle University, Newcastle upon Tyne, United Kingdom
- Renal Services, Newcastle Upon Tyne Hospitals National Health Service Trust, Newcastle upon Tyne, United Kingdom
- National Institute for Health Research Newcastle Biomedical Research Centre, Newcastle upon Tyne, United Kingdom
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44
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Butt L, Unnersjö-Jess D, Höhne M, Edwards A, Binz-Lotter J, Reilly D, Hahnfeldt R, Ziegler V, Fremter K, Rinschen MM, Helmstädter M, Ebert LK, Castrop H, Hackl MJ, Walz G, Brinkkoetter PT, Liebau MC, Tory K, Hoyer PF, Beck BB, Brismar H, Blom H, Schermer B, Benzing T. A molecular mechanism explaining albuminuria in kidney disease. Nat Metab 2020; 2:461-474. [PMID: 32694662 DOI: 10.1038/s42255-020-0204-y] [Citation(s) in RCA: 90] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Accepted: 04/07/2020] [Indexed: 01/18/2023]
Abstract
Mammalian kidneys constantly filter large amounts of liquid, with almost complete retention of albumin and other macromolecules in the plasma. Breakdown of the three-layered renal filtration barrier results in loss of albumin into urine (albuminuria) across the wall of small renal capillaries, and is a leading cause of chronic kidney disease. However, exactly how the renal filter works and why its permeability is altered in kidney diseases is poorly understood. Here we show that the permeability of the renal filter is modulated through compression of the capillary wall. We collect morphometric data prior to and after onset of albuminuria in a mouse model equivalent to a human genetic disease affecting the renal filtration barrier. Combining quantitative analyses with mathematical modelling, we demonstrate that morphological alterations of the glomerular filtration barrier lead to reduced compressive forces that counteract filtration pressure, thereby resulting in capillary dilatation, and ultimately albuminuria. Our results reveal distinct functions of the different layers of the filtration barrier and expand the molecular understanding of defective renal filtration in chronic kidney disease.
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Affiliation(s)
- Linus Butt
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - David Unnersjö-Jess
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
- Royal Institute of Technology, Stockholm, Sweden
| | - Martin Höhne
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Aurelie Edwards
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Julia Binz-Lotter
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Dervla Reilly
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Robert Hahnfeldt
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Vera Ziegler
- Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Katharina Fremter
- Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Markus M Rinschen
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
- Center for Mass Spectrometry and Metabolomics, The Scripps Research Institute, La Jolla, CA, USA
| | - Martin Helmstädter
- Department of Medicine IV, Medical Center - University of Freiburg, Faculty of Medicine, and Signalling Research Centres BIOSS and CIBSS, University of Freiburg,, Freiburg, Germany
| | - Lena K Ebert
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Hayo Castrop
- Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Matthias J Hackl
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Gerd Walz
- Department of Medicine IV, Medical Center - University of Freiburg, Faculty of Medicine, and Signalling Research Centres BIOSS and CIBSS, University of Freiburg,, Freiburg, Germany
| | - Paul T Brinkkoetter
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Max C Liebau
- Department of Pediatrics and Center for Molecular Medicine, University of Cologne, Faculty of Medicine and University Hospital of Cologne, Cologne, Germany
| | - Kálmán Tory
- MTA-SE Lendület Nephrogenetic Laboratory, 1st Department of Pediatrics, Semmelweis University, Budapest, Hungary
| | - Peter F Hoyer
- University Children's Hospital, Clinic for Pediatrics II, University of Duisburg-Essen, Essen, Germany
| | - Bodo B Beck
- Institute of Human Genetics and Center for Molecular Medicine, University of Cologne, Faculty of Medicine and University Hospital of Cologne, Cologne, Germany
| | | | - Hans Blom
- Royal Institute of Technology, Stockholm, Sweden
| | - Bernhard Schermer
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
- CECAD, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Thomas Benzing
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany.
- CECAD, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany.
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45
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Koehler S, Kuczkowski A, Kuehne L, Jüngst C, Hoehne M, Grahammer F, Eddy S, Kretzler M, Beck BB, Höhfeld J, Schermer B, Benzing T, Brinkkoetter PT, Rinschen MM. Proteome Analysis of Isolated Podocytes Reveals Stress Responses in Glomerular Sclerosis. J Am Soc Nephrol 2020; 31:544-559. [PMID: 32047005 DOI: 10.1681/asn.2019030312] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 12/04/2019] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Understanding podocyte-specific responses to injury at a systems level is difficult because injury leads to podocyte loss or an increase of extracellular matrix, altering glomerular cellular composition. Finding a window into early podocyte injury might help identify molecular pathways involved in the podocyte stress response. METHODS We developed an approach to apply proteome analysis to very small samples of purified podocyte fractions. To examine podocytes in early disease states in FSGS mouse models, we used podocyte fractions isolated from individual mice after chemical induction of glomerular disease (with Doxorubicin or LPS). We also applied single-glomerular proteome analysis to tissue from patients with FSGS. RESULTS Transcriptome and proteome analysis of glomeruli from patients with FSGS revealed an underrepresentation of podocyte-specific genes and proteins in late-stage disease. Proteome analysis of purified podocyte fractions from FSGS mouse models showed an early stress response that includes perturbations of metabolic, mechanical, and proteostasis proteins. Additional analysis revealed a high correlation between the amount of proteinuria and expression levels of the mechanosensor protein Filamin-B. Increased expression of Filamin-B in podocytes in biopsy samples from patients with FSGS, in single glomeruli from proteinuric rats, and in podocytes undergoing mechanical stress suggests that this protein has a role in detrimental stress responses. In Drosophila, nephrocytes with reduced filamin homolog Cher displayed altered filtration capacity, but exhibited no change in slit diaphragm structure. CONCLUSIONS We identified conserved mechanisms of the podocyte stress response through ultrasensitive proteome analysis of human glomerular FSGS tissue and purified native mouse podocytes during early disease stages. This approach enables systematic comparisons of large-scale proteomics data and phenotype-to-protein correlation.
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Affiliation(s)
- Sybille Koehler
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany.,Biomedical Sciences, University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | - Alexander Kuczkowski
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Lucas Kuehne
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Christian Jüngst
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany
| | - Martin Hoehne
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany
| | - Florian Grahammer
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Eppendorf, Hamburg, Germany
| | - Sean Eddy
- Division of Nephrology, Department of Internal Medicine, and
| | - Matthias Kretzler
- Division of Nephrology, Department of Internal Medicine, and.,Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan
| | - Bodo B Beck
- Department of Human Genetics, University Hospital Cologne, Cologne, Germany
| | - Jörg Höhfeld
- Cell Biology, University of Bonn, Bonn, Germany; and
| | - Bernhard Schermer
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany
| | - Thomas Benzing
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany
| | - Paul T Brinkkoetter
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany;
| | - Markus M Rinschen
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; .,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany.,Center for Metabolomics and Mass Spectrometry, The Scripps Research Institute, La Jolla, California
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46
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Endoplasmic reticulum stress and proteasome pathway involvement in human podocyte injury with a truncated COL4A3 mutation. Chin Med J (Engl) 2020; 132:1823-1832. [PMID: 31306228 PMCID: PMC6759124 DOI: 10.1097/cm9.0000000000000294] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Background: Collagen type IV (COL4)-related nephropathy includes a variety of kidney diseases that occur with or without extra-renal manifestations caused by COL4A3-5 mutations. Previous studies revealed several novel mutations, including three COL4A3 missense mutations (G619R, G801R, and C1616Y) and the COL4A3 chr:228172489delA c.4317delA p.Thr1440ProfsX87 frameshift mutation that resulted in a truncated NC1 domain (hereafter named COL4A3 c.4317delA); however, the mutation mechanisms that lead to podocyte injury remain unclear. This study aimed to further explore the mutation mechanisms that lead to podocyte injury. Methods: Wild-type (WT) and four mutant COL4A3 segments were constructed into a lentiviral plasmid, then stably transfected into human podocytes. Real-time polymerase chain reaction and Western blotting were applied to detect endoplasmic reticulum stress (ERS)- and apoptosis-related mRNA and protein levels. Then, human podocytes were treated with MG132 (a proteasome inhibitor) and brefeldin A (a transport protein inhibitor). The human podocyte findings were verified by the establishment of a mus-Col4a3 knockout mouse monoclonal podocyte using clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) technology. Results: Our data showed that COL4A3 mRNA was significantly overexpressed in the lentivirus stably transfected podocytes. Moreover, the COL4A3 protein level was significantly increased in all groups except the COL4A3 c.4317delA group. Compared to the other test groups, the COL4A3 c.4317delA group showed excessive ERS and apoptosis. Podocytes treated with MG132 showed remarkably increased intra-cellular expression of the COL4A3 c.4317delA mutation. MG132 intervention improved higher ERS and apoptosis levels in the COL4A3 c.4317delA group. Mouse monoclonal podocytes with COL4A3 chr:82717932insA c.4852insA p.Arg1618ThrfsX4 were successfully acquired; this NC1-truncated mutation suggested a higher level of ERS and relatively remarkable level of apoptosis compared to that of the WT group. Conclusions: We demonstrated that excessive ERS and ERS-induced apoptosis were involved in the podocyte injury caused by the NC1-truncated COL4A3 mutation. Furthermore, proteasome pathway intervention might become a potential treatment for collagen type IV-related nephropathy caused by a severely truncated COL4A3 mutation.
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47
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Kampf LL, Schneider R, Gerstner L, Thünauer R, Chen M, Helmstädter M, Amar A, Onuchic-Whitford AC, Loza Munarriz R, Berdeli A, Müller D, Schrezenmeier E, Budde K, Mane S, Laricchia KM, Rehm HL, MacArthur DG, Lifton RP, Walz G, Römer W, Bergmann C, Hildebrandt F, Hermle T. TBC1D8B Mutations Implicate RAB11-Dependent Vesicular Trafficking in the Pathogenesis of Nephrotic Syndrome. J Am Soc Nephrol 2019; 30:2338-2353. [PMID: 31732614 DOI: 10.1681/asn.2019040414] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 08/07/2019] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Mutations in about 50 genes have been identified as monogenic causes of nephrotic syndrome, a frequent cause of CKD. These genes delineated the pathogenetic pathways and rendered significant insight into podocyte biology. METHODS We used whole-exome sequencing to identify novel monogenic causes of steroid-resistant nephrotic syndrome (SRNS). We analyzed the functional significance of an SRNS-associated gene in vitro and in podocyte-like Drosophila nephrocytes. RESULTS We identified hemizygous missense mutations in the gene TBC1D8B in five families with nephrotic syndrome. Coimmunoprecipitation assays indicated interactions between TBC1D8B and active forms of RAB11. Silencing TBC1D8B in HEK293T cells increased basal autophagy and exocytosis, two cellular functions that are independently regulated by RAB11. This suggests that TBC1D8B plays a regulatory role by inhibiting endogenous RAB11. Coimmunoprecipitation assays showed TBC1D8B also interacts with the slit diaphragm protein nephrin, and colocalizes with it in immortalized cell lines. Overexpressed murine Tbc1d8b with patient-derived mutations had lower affinity for endogenous RAB11 and nephrin compared with wild-type Tbc1d8b protein. Knockdown of Tbc1d8b in Drosophila impaired function of the podocyte-like nephrocytes, and caused mistrafficking of Sns, the Drosophila ortholog of nephrin. Expression of Rab11 RNAi in nephrocytes entailed defective delivery of slit diaphragm protein to the membrane, whereas RAB11 overexpression revealed a partial phenotypic overlap to Tbc1d8b loss of function. CONCLUSIONS Novel mutations in TBC1D8B are monogenic causes of SRNS. This gene inhibits RAB11. Our findings suggest that RAB11-dependent vesicular nephrin trafficking plays a role in the pathogenesis of nephrotic syndrome.
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Affiliation(s)
- Lina L Kampf
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Ronen Schneider
- Division of Nephrology, Department of Pediatrics, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Lea Gerstner
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Roland Thünauer
- Signalling Research Centres BIOSS and CIBSS and Faculty of Biology, University of Freiburg, Freiburg, Germany.,Advanced Light and Fluorescence Microscopy Facility, Centre for Structural Systems Biology (CSSB) and University of Hamburg, Hamburg, Germany
| | - Mengmeng Chen
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Martin Helmstädter
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Ali Amar
- Division of Nephrology, Department of Pediatrics, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Ana C Onuchic-Whitford
- Division of Nephrology, Department of Pediatrics, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.,Renal Division, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | | | - Afig Berdeli
- Department of Pediatrics, Molecular Medicine Laboratory, Ege University, Izmir, Turkey
| | - Dominik Müller
- Department of Pediatric Nephrology, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Eva Schrezenmeier
- Department of Nephrology and Medical Intensive Care, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Klemens Budde
- Department of Nephrology and Medical Intensive Care, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Shrikant Mane
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut
| | - Kristen M Laricchia
- Broad Center for Mendelian Genomics, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge
| | - Heidi L Rehm
- Broad Center for Mendelian Genomics, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge
| | - Daniel G MacArthur
- Broad Center for Mendelian Genomics, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge
| | - Richard P Lifton
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut.,Laboratory of Human Genetics and Genomics, The Rockefeller University, New York, New York
| | - Gerd Walz
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Winfried Römer
- Signalling Research Centres BIOSS and CIBSS and Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Carsten Bergmann
- Center for Human Genetics, Mainz, Germany.,Center for Human Genetics, Bioscientia, Ingelheim, Germany; and.,Department of Medicine, University Hospital Freiburg, Freiburg, Germany
| | - Friedhelm Hildebrandt
- Division of Nephrology, Department of Pediatrics, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts;
| | - Tobias Hermle
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany;
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48
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Modeling Podocyte Biology Using Drosophila Nephrocytes. Methods Mol Biol 2019. [PMID: 31701442 DOI: 10.1007/978-1-4939-9841-8_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Vertebrate podocytes are kidney glomerular cells critically required for normal renal filtration. To fulfill their role, podocytes form molecular sieves known as slit diaphragms that contribute to the glomerular filtration barrier. The disruption of podocyte biology or slit diaphragm formation in humans is a precursor to albuminuria, renal failure, and cardiovascular morbidity. Due to genetic and functional similarities, the nephrocytes of Drosophila are increasingly used to model the genetic and metabolic basis of human podocyte biology. They have the advantage that they are a much quicker system to study compared to other murine transgenic models. In this chapter we present methods to modulate and study Drosophila nephrocyte function and diaphragm formation.
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49
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van den Ameele J, Brand AH. Neural stem cell temporal patterning and brain tumour growth rely on oxidative phosphorylation. eLife 2019; 8:47887. [PMID: 31513013 PMCID: PMC6763261 DOI: 10.7554/elife.47887] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 09/11/2019] [Indexed: 02/07/2023] Open
Abstract
Translating advances in cancer research to clinical applications requires better insight into the metabolism of normal cells and tumour cells in vivo. Much effort has focused on understanding how glycolysis and oxidative phosphorylation (OxPhos) support proliferation, while their impact on other aspects of development and tumourigenesis remain largely unexplored. We found that inhibition of OxPhos in neural stem cells (NSCs) or tumours in the Drosophila brain not only decreases proliferation, but also affects many different aspects of stem cell behaviour. In NSCs, OxPhos dysfunction leads to a protracted G1/S-phase and results in delayed temporal patterning and reduced neuronal diversity. As a consequence, NSCs fail to undergo terminal differentiation, leading to prolonged neurogenesis into adulthood. Similarly, in brain tumours inhibition of OxPhos slows proliferation and prevents differentiation, resulting in reduced tumour heterogeneity. Thus, in vivo, highly proliferative stem cells and tumour cells require OxPhos for efficient growth and generation of diversity.
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Affiliation(s)
- Jelle van den Ameele
- The Gurdon Institute, Cambridge, United Kingdom.,Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Andrea H Brand
- The Gurdon Institute, Cambridge, United Kingdom.,Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
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50
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Teumer A, Li Y, Ghasemi S, Prins BP, Wuttke M, Hermle T, Giri A, Sieber KB, Qiu C, Kirsten H, Tin A, Chu AY, Bansal N, Feitosa MF, Wang L, Chai JF, Cocca M, Fuchsberger C, Gorski M, Hoppmann A, Horn K, Li M, Marten J, Noce D, Nutile T, Sedaghat S, Sveinbjornsson G, Tayo BO, van der Most PJ, Xu Y, Yu Z, Gerstner L, Ärnlöv J, Bakker SJL, Baptista D, Biggs ML, Boerwinkle E, Brenner H, Burkhardt R, Carroll RJ, Chee ML, Chee ML, Chen M, Cheng CY, Cook JP, Coresh J, Corre T, Danesh J, de Borst MH, De Grandi A, de Mutsert R, de Vries APJ, Degenhardt F, Dittrich K, Divers J, Eckardt KU, Ehret G, Endlich K, Felix JF, Franco OH, Franke A, Freedman BI, Freitag-Wolf S, Gansevoort RT, Giedraitis V, Gögele M, Grundner-Culemann F, Gudbjartsson DF, Gudnason V, Hamet P, Harris TB, Hicks AA, Holm H, Foo VHX, Hwang SJ, Ikram MA, Ingelsson E, Jaddoe VWV, Jakobsdottir J, Josyula NS, Jung B, Kähönen M, Khor CC, Kiess W, Koenig W, Körner A, Kovacs P, Kramer H, Krämer BK, Kronenberg F, Lange LA, Langefeld CD, Lee JJM, Lehtimäki T, Lieb W, Lim SC, Lind L, Lindgren CM, Liu J, Loeffler M, Lyytikäinen LP, Mahajan A, Maranville JC, Mascalzoni D, McMullen B, Meisinger C, Meitinger T, Miliku K, Mook-Kanamori DO, Müller-Nurasyid M, Mychaleckyj JC, Nauck M, Nikus K, Ning B, Noordam R, Connell JO, Olafsson I, Palmer ND, Peters A, Podgornaia AI, Ponte B, Poulain T, Pramstaller PP, Rabelink TJ, Raffield LM, Reilly DF, Rettig R, Rheinberger M, Rice KM, Rivadeneira F, Runz H, Ryan KA, Sabanayagam C, Saum KU, Schöttker B, Shaffer CM, Shi Y, Smith AV, Strauch K, Stumvoll M, Sun BB, Szymczak S, Tai ES, Tan NYQ, Taylor KD, Teren A, Tham YC, Thiery J, Thio CHL, Thomsen H, Thorsteinsdottir U, Tönjes A, Tremblay J, Uitterlinden AG, van der Harst P, Verweij N, Vogelezang S, Völker U, Waldenberger M, Wang C, Wilson OD, Wong C, Wong TY, Yang Q, Yasuda M, Akilesh S, Bochud M, Böger CA, Devuyst O, Edwards TL, Ho K, Morris AP, Parsa A, Pendergrass SA, Psaty BM, Rotter JI, Stefansson K, Wilson JG, Susztak K, Snieder H, Heid IM, Scholz M, Butterworth AS, Hung AM, Pattaro C, Köttgen A. Genome-wide association meta-analyses and fine-mapping elucidate pathways influencing albuminuria. Nat Commun 2019; 10:4130. [PMID: 31511532 PMCID: PMC6739370 DOI: 10.1038/s41467-019-11576-0] [Citation(s) in RCA: 125] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 07/23/2019] [Indexed: 02/08/2023] Open
Abstract
Increased levels of the urinary albumin-to-creatinine ratio (UACR) are associated with higher risk of kidney disease progression and cardiovascular events, but underlying mechanisms are incompletely understood. Here, we conduct trans-ethnic (n = 564,257) and European-ancestry specific meta-analyses of genome-wide association studies of UACR, including ancestry- and diabetes-specific analyses, and identify 68 UACR-associated loci. Genetic correlation analyses and risk score associations in an independent electronic medical records database (n = 192,868) reveal connections with proteinuria, hyperlipidemia, gout, and hypertension. Fine-mapping and trans-Omics analyses with gene expression in 47 tissues and plasma protein levels implicate genes potentially operating through differential expression in kidney (including TGFB1, MUC1, PRKCI, and OAF), and allow coupling of UACR associations to altered plasma OAF concentrations. Knockdown of OAF and PRKCI orthologs in Drosophila nephrocytes reduces albumin endocytosis. Silencing fly PRKCI further impairs slit diaphragm formation. These results generate a priority list of genes and pathways for translational research to reduce albuminuria.
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Affiliation(s)
- Alexander Teumer
- Institute for Community Medicine, University Medicine Greifswald, Greifswald, Germany.
- DZHK (German Center for Cardiovascular Research), Partner Site Greifswald, Greifswald, Germany.
| | - Yong Li
- Institute of Genetic Epidemiology, Department of Biometry, Epidemiology and Medical Bioinformatics, Faculty of Medicine and Medical Center - University of Freiburg, Freiburg, Germany
| | - Sahar Ghasemi
- Institute for Community Medicine, University Medicine Greifswald, Greifswald, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Greifswald, Greifswald, Germany
| | - Bram P Prins
- MRC/BHF Cardiovascular Epidemiology Unit, Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK
| | - Matthias Wuttke
- Institute of Genetic Epidemiology, Department of Biometry, Epidemiology and Medical Bioinformatics, Faculty of Medicine and Medical Center - University of Freiburg, Freiburg, Germany
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center - University of Freiburg, Freiburg, Germany
| | - Tobias Hermle
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center - University of Freiburg, Freiburg, Germany
| | - Ayush Giri
- Division of Quantitative Sciences, Department of Obstetrics & Gynecology, Vanderbilt Genetics Institute, Vanderbilt Epidemiology Center, Institute for Medicine and Public Health, Vanderbilt University Medical Center, Nashville, TN, USA
- Biomedical Laboratory Research and Development, Tennessee Valley Healthcare System (626)/Vanderbilt University, Nashville, TN, USA
| | - Karsten B Sieber
- Target Sciences - Genetics, GlaxoSmithKline, Collegeville, PA, USA
| | - Chengxiang Qiu
- Renal Electrolyte and Hypertension Division, Department of Medicine, Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Pennsylvania, PA, USA
| | - Holger Kirsten
- Institute for Medical Informatics, Statistics and Epidemiology, University of Leipzig, Leipzig, Germany
- LIFE Research Centre for Civilization Diseases, University of Leipzig, Leipzig, Germany
| | - Adrienne Tin
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
- Epidemiology and Clinical Research, Welch Centre for Prevention, Baltimore, MD, USA
| | - Audrey Y Chu
- Genetics, Merck & Co., Inc., Kenilworth, NJ, USA
| | - Nisha Bansal
- Division of Nephrology, University of Washington, Seattle, WA, USA
- Kidney Research Institute, University of Washington, Seattle, WA, USA
| | - Mary F Feitosa
- Division of Statistical Genomics, Department of Genetics, Washington University School of Medicine, St. Louis, MO, USA
| | - Lihua Wang
- Division of Statistical Genomics, Department of Genetics, Washington University School of Medicine, St. Louis, MO, USA
| | - Jin-Fang Chai
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore, Singapore
| | - Massimiliano Cocca
- Institute for Maternal and Child Health - IRCCS "Burlo Garofolo", Trieste, Italy
| | - Christian Fuchsberger
- Eurac Research, Institute for Biomedicine (affiliated to the University of Lübeck), Bolzano, Italy
| | - Mathias Gorski
- Department of Nephrology, University Hospital Regensburg, Regensburg, Germany
- Department of Genetic Epidemiology, University of Regensburg, Regensburg, Germany
| | - Anselm Hoppmann
- Institute of Genetic Epidemiology, Department of Biometry, Epidemiology and Medical Bioinformatics, Faculty of Medicine and Medical Center - University of Freiburg, Freiburg, Germany
| | - Katrin Horn
- Institute for Medical Informatics, Statistics and Epidemiology, University of Leipzig, Leipzig, Germany
- LIFE Research Centre for Civilization Diseases, University of Leipzig, Leipzig, Germany
| | - Man Li
- Department of Medicine, Division of Nephrology and Hypertension, University of Utah, Salt Lake City, UT, USA
| | - Jonathan Marten
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Damia Noce
- Eurac Research, Institute for Biomedicine (affiliated to the University of Lübeck), Bolzano, Italy
| | - Teresa Nutile
- Institute of Genetics and Biophysics "Adriano Buzzati-Traverso" - CNR, Naples, Italy
| | - Sanaz Sedaghat
- Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | | | - Bamidele O Tayo
- Department of Public Health Sciences, Loyola University Chicago, Maywood, IL, USA
| | - Peter J van der Most
- Department of Epidemiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Yizhe Xu
- Department of Medicine, Division of Nephrology and Hypertension, University of Utah, Salt Lake City, UT, USA
| | - Zhi Yu
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Lea Gerstner
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center - University of Freiburg, Freiburg, Germany
| | - Johan Ärnlöv
- Department of Neurobiology, Care Sciences and Society, Division of Family Medicine and Primary Care, Karolinska Institutet, Stockholm, Sweden
- School of Health and Social Studies, Dalarna University, Falun, Sweden
| | - Stephan J L Bakker
- Department of Internal Medicine, Division of Nephrology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | | | - Mary L Biggs
- Cardiovascular Health Research Unit, Department of Medicine, University of Washington, Seattle, WA, USA
- Department of Biostatistics, University of Washington, Seattle, WA, USA
| | - Eric Boerwinkle
- Human Genetics Centre, University of Texas Health Science Centre, Houston, TX, USA
| | - Hermann Brenner
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Centre (DKFZ), Heidelberg, Germany
- Network Aging Research, University of Heidelberg, Heidelberg, Germany
| | - Ralph Burkhardt
- LIFE Research Centre for Civilization Diseases, University of Leipzig, Leipzig, Germany
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University of Leipzig, Leipzig, Germany
- Institute of Clinical Chemistry and Laboratory Medicine, University Hospital Regensburg, Regensburg, Germany
| | - Robert J Carroll
- Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Miao-Li Chee
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Miao-Ling Chee
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Mengmeng Chen
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center - University of Freiburg, Freiburg, Germany
| | - Ching-Yu Cheng
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- Ophthalmology & Visual Sciences Academic Clinical Program (Eye ACP), Duke-NUS Medical School, Singapore, Singapore
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore, Singapore
| | - James P Cook
- Department of Biostatistics, University of Liverpool, Liverpool, UK
| | - Josef Coresh
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Tanguy Corre
- Center for Primary Care and Public Health (Unisanté), University of Lausanne, Lausanne, Switzerland
- Department of Computational Biology, University of Lausanne, Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - John Danesh
- Department of Public Health and Primary Care, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Martin H de Borst
- Department of Internal Medicine, Division of Nephrology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Alessandro De Grandi
- Eurac Research, Institute for Biomedicine (affiliated to the University of Lübeck), Bolzano, Italy
| | - Renée de Mutsert
- Department of Clinical Epidemiology, Leiden University Medical Centre, Leiden, The Netherlands
| | - Aiko P J de Vries
- Section of Nephrology, Department of Internal Medicine, Leiden University Medical Centre, Leiden, The Netherlands
| | - Frauke Degenhardt
- Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Katalin Dittrich
- Department of Women and Child Health, Hospital for Children and Adolescents, University of Leipzig, Leipzig, Germany
- Centre for Pediatric Research, University of Leipzig, Leipzig, Germany
| | - Jasmin Divers
- Department of Biostatistics and Data Science, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Kai-Uwe Eckardt
- Intensive Care Medicine, Charité, Berlin, Germany
- Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Georg Ehret
- Cardiology, Geneva University Hospitals, Geneva, Switzerland
| | - Karlhans Endlich
- DZHK (German Center for Cardiovascular Research), Partner Site Greifswald, Greifswald, Germany
- Department of Anatomy and Cell Biology, University Medicine Greifswald, Greifswald, Germany
| | - Janine F Felix
- Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
- The Generation R Study Group, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
- Department of Pediatrics, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Oscar H Franco
- Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
- Institute of Social and Preventive Medicine (ISPM), University of Bern, Bern, Switzerland
| | - Andre Franke
- Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Barry I Freedman
- Internal Medicine - Section on Nephrology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Sandra Freitag-Wolf
- Institute of Medical Informatics and Statistics, Kiel University, University Hospital Schleswig-Holstein, Kiel, USA
| | - Ron T Gansevoort
- Department of Internal Medicine, Division of Nephrology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Vilmantas Giedraitis
- Department of Public Health and Caring Sciences, Molecular Geriatrics, Uppsala University, Uppsala, Sweden
| | - Martin Gögele
- Eurac Research, Institute for Biomedicine (affiliated to the University of Lübeck), Bolzano, Italy
| | - Franziska Grundner-Culemann
- Institute of Genetic Epidemiology, Department of Biometry, Epidemiology and Medical Bioinformatics, Faculty of Medicine and Medical Center - University of Freiburg, Freiburg, Germany
| | | | - Vilmundur Gudnason
- Icelandic Heart Association, Kopavogur, Iceland
- Faculty of Medicine, School of Health Sciences, University of Iceland, Reykjavik, Iceland
| | - Pavel Hamet
- Montreal University Hospital Research Centre, CHUM, Montreal, QC, Canada
- Medpharmgene, Montreal, QC, Canada
| | - Tamara B Harris
- Laboratory of Epidemiology and Population Sciences, National Institute on Aging, Intramural Research Program, National Institutes of Health, Bethesda, MD, USA
| | - Andrew A Hicks
- Eurac Research, Institute for Biomedicine (affiliated to the University of Lübeck), Bolzano, Italy
| | - Hilma Holm
- deCODE Genetics, Amgen Inc., Reykjavik, Iceland
| | - Valencia Hui Xian Foo
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Shih-Jen Hwang
- NHLBI's Framingham Heart Study, Framingham, MA, USA
- The Centre for Population Studies, NHLBI, Framingham, MA, USA
| | - M Arfan Ikram
- Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Erik Ingelsson
- Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA, USA
- Stanford Cardiovascular Institute, Stanford University, Stanford, CA, USA
- Molecular Epidemiology and Science for Life Laboratory, Department of Medical Sciences, Uppsala University, Uppsala, Sweden
- Stanford Diabetes Research Center, Stanford University, Stanford, CA, USA
| | - Vincent W V Jaddoe
- Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
- The Generation R Study Group, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
- Department of Pediatrics, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Johanna Jakobsdottir
- Icelandic Heart Association, Holtasmari 1, Kopavogur, IS-201, Iceland
- The Centre of Public Health Sciences, University of Iceland, Sturlugata 8, Reykjavík, IS-101, Iceland
| | - Navya Shilpa Josyula
- Geisinger Research, Biomedical and Translational Informatics Institute, Rockville, MD, USA
| | - Bettina Jung
- Department of Nephrology, University Hospital Regensburg, Regensburg, Germany
| | - Mika Kähönen
- Department of Clinical Physiology, Tampere University Hospital, Tampere, Finland
- Department of Clinical Physiology, Finnish Cardiovascular Research Center - Tampere, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Chiea-Chuen Khor
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- Genome Institute of Singapore, Agency for Science Technology and Research, Singapore, Singapore
| | - Wieland Kiess
- LIFE Research Centre for Civilization Diseases, University of Leipzig, Leipzig, Germany
- Department of Women and Child Health, Hospital for Children and Adolescents, University of Leipzig, Leipzig, Germany
- Centre for Pediatric Research, University of Leipzig, Leipzig, Germany
| | - Wolfgang Koenig
- Deutsches Herzzentrum München, Technische Universität München, Munich, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich, Germany
- Institute of Epidemiology and Biostatistics, University of Ulm, Ulm, Germany
| | - Antje Körner
- LIFE Research Centre for Civilization Diseases, University of Leipzig, Leipzig, Germany
- Department of Women and Child Health, Hospital for Children and Adolescents, University of Leipzig, Leipzig, Germany
- Centre for Pediatric Research, University of Leipzig, Leipzig, Germany
| | - Peter Kovacs
- Integrated Research and Treatment Centre Adiposity Diseases, University of Leipzig, Leipzig, Germany
| | - Holly Kramer
- Department of Public Health Sciences, Loyola University Chicago, Maywood, IL, USA
- Division of Nephrology and Hypertension, Loyola University Chicago, Chicago, IL, USA
| | - Bernhard K Krämer
- 5th Department of Medicine (Nephrology, Hypertensiology, Rheumatology, Endocrinology, Diabetology), Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Florian Kronenberg
- Division of Genetic Epidemiology, Department of Medical Genetics, Molecular and Clinical Pharmacology, Medical University of Innsbruck, Innsbruck, Austria
| | - Leslie A Lange
- Division of Biomedical Informatics and Personalized Medicine, School of Medicine, University of Colorado Denver - Anschutz Medical Campus, Aurora, CO, USA
| | - Carl D Langefeld
- Department of Biostatistics and Data Science, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Jeannette Jen-Mai Lee
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore, Singapore
| | - Terho Lehtimäki
- Department of Clinical Chemistry, Fimlab Laboratories, Tampere, Finland
- Department of Clinical Chemistry, Finnish Cardiovascular Research Center - Tampere, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Wolfgang Lieb
- Institute of Epidemiology and Biobank Popgen, Kiel University, Kiel, Germany
| | - Su-Chi Lim
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore, Singapore
- Diabetes Centre, Khoo Teck Puat Hospital, Singapore, Singapore
| | - Lars Lind
- Cardiovascular Epidemiology, Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Cecilia M Lindgren
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
| | - Jianjun Liu
- Genome Institute of Singapore, Agency for Science Technology and Research, Singapore, Singapore
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore, Singapore
| | - Markus Loeffler
- Institute for Medical Informatics, Statistics and Epidemiology, University of Leipzig, Leipzig, Germany
- LIFE Research Centre for Civilization Diseases, University of Leipzig, Leipzig, Germany
| | - Leo-Pekka Lyytikäinen
- Department of Clinical Chemistry, Fimlab Laboratories, Tampere, Finland
- Department of Clinical Chemistry, Finnish Cardiovascular Research Center - Tampere, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Anubha Mahajan
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford, UK
| | | | - Deborah Mascalzoni
- Eurac Research, Institute for Biomedicine (affiliated to the University of Lübeck), Bolzano, Italy
| | | | - Christa Meisinger
- Independent Research Group Clinical Epidemiology, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany
- Chair of Epidemiology Ludwig- Maximilians-Universität München at UNIKA-T Augsburg, Augsburg, Germany
| | - Thomas Meitinger
- DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich, Germany
- Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany
- Institute of Human Genetics, Technische Universität München, Munich, Germany
| | - Kozeta Miliku
- Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
- The Generation R Study Group, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
- Department of Pediatrics, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Dennis O Mook-Kanamori
- Department of Clinical Epidemiology, Leiden University Medical Centre, Leiden, The Netherlands
- Department of Public Health and Primary Care, Leiden University Medical Centre, Leiden, The Netherlands
| | - Martina Müller-Nurasyid
- Institute of Genetic Epidemiology, Helmholtz Zentrum München - German Research Centre for Environmental Health, Neuherberg, Germany
- Chair of Genetic Epidemiology, IBE, Faculty of Medicine, LMU, Munich, Germany
- Department of Internal Medicine I (Cardiology), Hospital of the Ludwig-Maximilians-University (LMU) Munich, Munich, Germany
| | - Josyf C Mychaleckyj
- Centre for Public Health Genomics, University of Virginia, Charlottesville, VA, USA
| | - Matthias Nauck
- DZHK (German Center for Cardiovascular Research), Partner Site Greifswald, Greifswald, Germany
- Institute of Clinical Chemistry and Laboratory Medicine, University Medicine Greifswald, Greifswald, Germany
| | - Kjell Nikus
- Department of Cardiology, Heart Center, Tampere University Hospital, Tampere, Finland
- Department of Cardiology, Finnish Cardiovascular Research Center - Tampere, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Boting Ning
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - Raymond Noordam
- Section of Gerontology and Geriatrics, Department of Internal Medicine, Leiden University Medical Centre, Leiden, The Netherlands
| | | | - Isleifur Olafsson
- Department of Clinical Biochemistry, Landspitali University Hospital, Reykjavik, Iceland
| | | | - Annette Peters
- DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich, Germany
- Institute of Epidemiology, Helmholtz Zentrum München - German Research Centre for Environmental Health, Neuherberg, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | | | - Belen Ponte
- Service de Néphrologie, Geneva University Hospitals, Geneva, Switzerland
| | - Tanja Poulain
- LIFE Research Centre for Civilization Diseases, University of Leipzig, Leipzig, Germany
| | - Peter P Pramstaller
- Eurac Research, Institute for Biomedicine (affiliated to the University of Lübeck), Bolzano, Italy
| | - Ton J Rabelink
- Section of Nephrology, Department of Internal Medicine, Leiden University Medical Centre, Leiden, The Netherlands
- Einthoven Laboratory of Experimental Vascular Research, Leiden University Medical Centre, Leiden, The Netherlands
| | - Laura M Raffield
- Department of Genetics, University of North Carolina, Chapel Hill, NC, USA
| | | | - Rainer Rettig
- Institute of Physiology, University Medicine Greifswald, Karlsburg, Germany
| | - Myriam Rheinberger
- Department of Nephrology, University Hospital Regensburg, Regensburg, Germany
| | - Kenneth M Rice
- Department of Biostatistics, University of Washington, Seattle, WA, USA
| | - Fernando Rivadeneira
- Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
- Department of Internal Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Heiko Runz
- MRL, Merck & Co., Inc., Kenilworth, NJ, USA
- Biogen Inc., Cambridge, MA, USA
| | - Kathleen A Ryan
- Division of Endocrinology, Diabetes and Nutrition, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Charumathi Sabanayagam
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- Ophthalmology & Visual Sciences Academic Clinical Program (Eye ACP), Duke-NUS Medical School, Singapore, Singapore
| | - Kai-Uwe Saum
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Centre (DKFZ), Heidelberg, Germany
| | - Ben Schöttker
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Centre (DKFZ), Heidelberg, Germany
- Network Aging Research, University of Heidelberg, Heidelberg, Germany
| | - Christian M Shaffer
- Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Yuan Shi
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- Ophthalmology & Visual Sciences Academic Clinical Program (Eye ACP), Duke-NUS Medical School, Singapore, Singapore
| | - Albert V Smith
- Faculty of Medicine, School of Health Sciences, University of Iceland, Reykjavik, Iceland
| | - Konstantin Strauch
- Institute of Genetic Epidemiology, Helmholtz Zentrum München - German Research Centre for Environmental Health, Neuherberg, Germany
- Chair of Genetic Epidemiology, IBE, Faculty of Medicine, LMU, Munich, Germany
| | - Michael Stumvoll
- Department of Endocrinology and Nephrology, University of Leipzig, Leipzig, Germany
| | - Benjamin B Sun
- MRC/BHF Cardiovascular Epidemiology Unit, Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK
| | - Silke Szymczak
- Institute of Medical Informatics and Statistics, Kiel University, University Hospital Schleswig-Holstein, Kiel, USA
| | - E-Shyong Tai
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore, Singapore
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore, Singapore
- Duke-NUS Medical School, Singapore, Singapore
| | - Nicholas Y Q Tan
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Kent D Taylor
- The Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - Andrej Teren
- LIFE Research Centre for Civilization Diseases, University of Leipzig, Leipzig, Germany
- Heart Centre Leipzig, Leipzig, Germany
| | - Yih-Chung Tham
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Joachim Thiery
- LIFE Research Centre for Civilization Diseases, University of Leipzig, Leipzig, Germany
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University of Leipzig, Leipzig, Germany
| | - Chris H L Thio
- Department of Epidemiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Hauke Thomsen
- Division of Molecular Genetic Epidemiology, German Cancer Research Centre (DKFZ), Heidelberg, Germany
| | | | - Anke Tönjes
- Department of Endocrinology and Nephrology, University of Leipzig, Leipzig, Germany
| | - Johanne Tremblay
- Montreal University Hospital Research Centre, CHUM, Montreal, QC, Canada
- CRCHUM, Montreal, QC, Canada
| | - André G Uitterlinden
- Department of Internal Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Pim van der Harst
- Department of Cardiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- Department of Genetics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- Durrer Centre for Cardiovascular Research, The Netherlands Heart Institute, Utrecht, The Netherlands
| | - Niek Verweij
- Department of Cardiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Suzanne Vogelezang
- Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
- The Generation R Study Group, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
- Department of Pediatrics, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Uwe Völker
- DZHK (German Center for Cardiovascular Research), Partner Site Greifswald, Greifswald, Germany
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Melanie Waldenberger
- DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich, Germany
- Institute of Epidemiology, Helmholtz Zentrum München - German Research Centre for Environmental Health, Neuherberg, Germany
- Research Unit of Molecular Epidemiology, Helmholtz Zentrum München - German Research Centre for Environmental Health, Neuherberg, Germany
| | - Chaolong Wang
- Genome Institute of Singapore, Agency for Science Technology and Research, Singapore, Singapore
- School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Otis D Wilson
- Vanderbilt University Medical Centre, Division of Nephrology & Hypertension, Nashville, TN, USA
| | - Charlene Wong
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore, Singapore
| | - Tien-Yin Wong
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- Ophthalmology & Visual Sciences Academic Clinical Program (Eye ACP), Duke-NUS Medical School, Singapore, Singapore
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore, Singapore
| | - Qiong Yang
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - Masayuki Yasuda
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Shreeram Akilesh
- Kidney Research Institute, University of Washington, Seattle, WA, USA
- Anatomic Pathology, University of Washington Medical Center, Seattle, WA, USA
| | - Murielle Bochud
- Center for Primary Care and Public Health (Unisanté), University of Lausanne, Lausanne, Switzerland
| | - Carsten A Böger
- Department of Nephrology, University Hospital Regensburg, Regensburg, Germany
- Department of Nephrology, Diabetology and Rheumatology, Kliniken Südostbayern, Traunstein, Germany
| | - Olivier Devuyst
- Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Todd L Edwards
- Division of Epidemiology, Department of Medicine, Vanderbilt Genetics Institute, Vanderbilt University Medical Centre, Nashville, TN, USA
- Department of Veteran's Affairs, Tennessee Valley Healthcare System (626)/Vanderbilt University, Nashville, TN, USA
| | - Kevin Ho
- Kidney Health Research Institute (KHRI), Geisinger, Danville, PA, USA
- Department of Nephrology, Geisinger, Danville, PA, USA
| | - Andrew P Morris
- Department of Biostatistics, University of Liverpool, Liverpool, UK
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Afshin Parsa
- Division of Kidney, Urologic and Hematologic Diseases, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
- Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Sarah A Pendergrass
- Geisinger Research, Biomedical and Translational Informatics Institute, Danville, PA, USA
| | - Bruce M Psaty
- Cardiovascular Health Research Unit, Department of Medicine, Department of Epidemiology, Department of Health Service, University of Washington, Seattle, WA, USA
- Kaiser Permanente Washington Health Research Institute, Seattle, WA, USA
| | - Jerome I Rotter
- The Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA
- Department of Pediatrics, Harbor-UCLA Medical Centre, Torrance, CA, USA
- Department of Medicine, Harbor-UCLA Medical Centre, Torrance, CA, USA
| | | | - James G Wilson
- Department of Physiology and Biophysics, University of Mississippi Medical Centre, Jackson, MS, USA
| | - Katalin Susztak
- Renal Electrolyte and Hypertension Division, Department of Medicine, Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Pennsylvania, PA, USA
| | - Harold Snieder
- Department of Epidemiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Iris M Heid
- Department of Genetic Epidemiology, University of Regensburg, Regensburg, Germany
| | - Markus Scholz
- Institute for Medical Informatics, Statistics and Epidemiology, University of Leipzig, Leipzig, Germany
- LIFE Research Centre for Civilization Diseases, University of Leipzig, Leipzig, Germany
| | - Adam S Butterworth
- MRC/BHF Cardiovascular Epidemiology Unit, Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK
- National Institute for Health Research Blood and Transplant Research Unit in Donor Health and Genomics, University of Cambridge, Cambridge, UK
| | - Adriana M Hung
- Vanderbilt University Medical Centre, Division of Nephrology & Hypertension, Nashville, TN, USA
- Department of Veteran's Affairs, Tennessee Valley Healthcare System (626)/Vanderbilt University, Nashville, TN, USA
| | - Cristian Pattaro
- Eurac Research, Institute for Biomedicine (affiliated to the University of Lübeck), Bolzano, Italy.
| | - Anna Köttgen
- Institute of Genetic Epidemiology, Department of Biometry, Epidemiology and Medical Bioinformatics, Faculty of Medicine and Medical Center - University of Freiburg, Freiburg, Germany.
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
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