1
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Königshausen E, Zierhut UM, Ruetze M, Rump LC, Sellin L. A molecular mechanism for angiotensin II receptor blocker-mediated slit membrane protection: Angiotensin II increases nephrin endocytosis via AT1-receptor-dependent ERK 1/2 activation. FASEB J 2024; 38:e70018. [PMID: 39212304 DOI: 10.1096/fj.202400369r] [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: 02/17/2024] [Revised: 07/31/2024] [Accepted: 08/19/2024] [Indexed: 09/04/2024]
Abstract
Albuminuria is characterized by a disruption of the glomerular filtration barrier, which is composed of the fenestrated endothelium, the glomerular basement membrane, and the slit diaphragm. Nephrin is a major component of the slit diaphragm. Apart from hemodynamic effects, Ang II enhances albuminuria by β-Arrestin2-mediated nephrin endocytosis. Blocking the AT1 receptor with candesartan and irbesartan reduces the Ang II-mediated nephrin-β-Arrestin2 interaction. The inhibition of MAPK ERK 1/2 blocks Ang II-enhanced nephrin-β-Arrestin2 binding. ERK 1/2 signaling, which follows AT1 receptor activation, is mediated by G-protein signaling, EGFR transactivation, and β-Arrestin2 recruitment. A mutant AT1 receptor defective in EGFR transactivation and β-Arrestin2 recruitment reduces the Ang II-mediated increase in nephrin β-Arrestin2 binding. The mutation of β-Arrestin2K11,K12, critical for AT1 receptor binding, completely abrogates the interaction with nephrin, independent of Ang II stimulation. β-Arrestin2K11R,K12R does not influence nephrin cell surface expression. The data presented here deepen our molecular understanding of a blood-pressure-independent molecular mechanism of AT-1 receptor blockers (ARBs) in reducing albuminuria.
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Affiliation(s)
- Eva Königshausen
- Department of Nephrology, Medical School Duesseldorf, Heinrich Heine University, Duesseldorf, Germany
| | - Ulf M Zierhut
- Department of Nephrology, Medical School Duesseldorf, Heinrich Heine University, Duesseldorf, Germany
| | - Martin Ruetze
- Department of Nephrology, Medical School Duesseldorf, Heinrich Heine University, Duesseldorf, Germany
| | - Lars C Rump
- Department of Nephrology, Medical School Duesseldorf, Heinrich Heine University, Duesseldorf, Germany
| | - Lorenz Sellin
- Department of Nephrology, Medical School Duesseldorf, Heinrich Heine University, Duesseldorf, Germany
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2
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Abhinay A, Agarwal A, Singh A, Kumar N. Novel Variations in KIRREL1 Gene and Infantile Onset Nephrotic Syndrome. Indian J Nephrol 2024; 34:547-548. [PMID: 39372610 PMCID: PMC11450837 DOI: 10.25259/ijn_55_2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2024] [Accepted: 02/04/2024] [Indexed: 10/08/2024] Open
Affiliation(s)
- Abhishek Abhinay
- Division of Pediatric Nephrology, Department of Pediatrics, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| | - Aditi Agarwal
- Division of Pediatric Nephrology, Department of Pediatrics, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| | - Ankur Singh
- Division of Pediatric Nephrology, Department of Pediatrics, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| | - Nitish Kumar
- Division of Pediatric Nephrology, Department of Pediatrics, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
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3
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Le Berre L, Tilly G, Pilet P, Brouard S, Dantal J. The Immunosuppressive Drug LF15-0195 Acts Also on Glomerular Lesions, by a Change in Cytoskeleton Distribution in Podocyte. Am J Nephrol 2024; 55:583-596. [PMID: 39074452 DOI: 10.1159/000539965] [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: 03/08/2024] [Accepted: 06/18/2024] [Indexed: 07/31/2024]
Abstract
INTRODUCTION Buffalo/Mna rats spontaneously develop nephrotic syndrome (NS) which recurs after renal transplantation. The immunosuppressive drug LF15-0195 can promote regression of the initial and post-transplantation nephropathy via induction of regulatory T cells. We investigate if this drug has an additional effect on the expression and localization of podocyte specific proteins. METHODS Buffalo/Mna kidney samples were collected before and after the occurrence of proteinuria, and after the remission of proteinuria induced by LF15-0195 treatment and compared by quantitative RT-PCR, Western blot, electron, and confocal microscopy to kidney samples of age-matched healthy rats. Cytoskeleton changes were assessed in culture by stress fibers induction by TNFα. RESULTS We observed, by electron microscopy, a restoration of foot process architecture in the LF15-0195-treated Buff/Mna kidneys, consistent with proteinuria remission. Nephrin, podocin, CD2AP, and α-actinin-4 mRNA levels remained low during the active disease in the Buff/Mna, in comparison with healthy rats which increase, while podocalyxin and synaptopodin transcripts were elevated before the occurrence of the disease but did not differ from healthy animals after. No difference in the mRNA and protein expression between the untreated and the LF15-0195-treated proteinuric Buff/Mna were seen for these 6 proteins. No changes were observed by confocal microscopy in the protein distribution at a cellular level, but a more homogenous distribution similar to healthy rats, was observed within the glomeruli of LF15-0195-treated rats. In addition, LF15-0195 could partially restore actin cytoskeleton of endothelial cells in TNFα-induced-cell stress experiment. CONCLUSION The effect of LF15-0195 treatment appears to be mediated by 2 mechanisms: an immunomodulatory effect via regulatory T cells induction, described in our previous work and which can act on immune cell involved in the disease pathogenesis, and an effect on the restoration of podocyte cytoskeleton, independent of expression levels of the proteins involved in the slit diaphragm and podocyte function, showed in this article.
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Affiliation(s)
- Ludmilla Le Berre
- Center for Research in Transplantation and Translational Immunology, UMR 1064, ITUN, CHU Nantes, Nantes Université, INSERM, Nantes, France
| | - Gaëlle Tilly
- Center for Research in Transplantation and Translational Immunology, UMR 1064, ITUN, CHU Nantes, Nantes Université, INSERM, Nantes, France
| | - Paul Pilet
- Regenerative Medicine and Skeleton, RMeS, UMR 1229, Oniris, Nantes Université, INSERM, Nantes, France
| | - Sophie Brouard
- Center for Research in Transplantation and Translational Immunology, UMR 1064, ITUN, CHU Nantes, Nantes Université, INSERM, Nantes, France
| | - Jacques Dantal
- Center for Research in Transplantation and Translational Immunology, UMR 1064, ITUN, CHU Nantes, Nantes Université, INSERM, Nantes, France
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4
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Baltar J, Miranda RM, Cabral M, Rebelo S, Grahammer F, Huber TB, Reguenga C, Monteiro FA. Neph1 is required for neurite branching and is negatively regulated by the PRRXL1 homeodomain factor in the developing spinal cord dorsal horn. Neural Dev 2024; 19:13. [PMID: 39049046 PMCID: PMC11271021 DOI: 10.1186/s13064-024-00190-6] [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: 05/16/2024] [Accepted: 07/05/2024] [Indexed: 07/27/2024] Open
Abstract
The cell-adhesion molecule NEPH1 is required for maintaining the structural integrity and function of the glomerulus in the kidneys. In the nervous system of Drosophila and C. elegans, it is involved in synaptogenesis and axon branching, which are essential for establishing functional circuits. In the mammalian nervous system, the expression regulation and function of Neph1 has barely been explored. In this study, we provide a spatiotemporal characterization of Neph1 expression in mouse dorsal root ganglia (DRGs) and spinal cord. After the neurogenic phase, Neph1 is broadly expressed in the DRGs and in their putative targets at the dorsal horn of the spinal cord, comprising both GABAergic and glutamatergic neurons. Interestingly, we found that PRRXL1, a homeodomain transcription factor that is required for proper establishment of the DRG-spinal cord circuit, prevents a premature expression of Neph1 in the superficial laminae of the dorsal spinal cord at E14.5, but has no regulatory effect on the DRGs or on either structure at E16.5. By chromatin immunoprecipitation analysis of the dorsal spinal cord, we identified four PRRXL1-bound regions within the Neph1 introns, suggesting that PRRXL1 directly regulates Neph1 transcription. We also showed that Neph1 is required for branching, especially at distal neurites. Together, our work showed that Prrxl1 prevents the early expression of Neph1 in the superficial dorsal horn, suggesting that Neph1 might function as a downstream effector gene for proper assembly of the DRG-spinal nociceptive circuit.
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Affiliation(s)
- João Baltar
- Unidade de Biologia Experimental, Departamento de Biomedicina, FMUP - Faculdade de Medicina da Universidade do Porto, Porto, Portugal
- Pain Neurobiology, IBMC - Instituto de Biologia Celular e Molecular, Porto, Portugal
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Rafael Mendes Miranda
- Unidade de Biologia Experimental, Departamento de Biomedicina, FMUP - Faculdade de Medicina da Universidade do Porto, Porto, Portugal
- Pain Neurobiology, IBMC - Instituto de Biologia Celular e Molecular, Porto, Portugal
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Maria Cabral
- Unidade de Biologia Experimental, Departamento de Biomedicina, FMUP - Faculdade de Medicina da Universidade do Porto, Porto, Portugal
- Pain Neurobiology, IBMC - Instituto de Biologia Celular e Molecular, Porto, Portugal
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Sandra Rebelo
- Unidade de Biologia Experimental, Departamento de Biomedicina, FMUP - Faculdade de Medicina da Universidade do Porto, Porto, Portugal
- Pain Neurobiology, IBMC - Instituto de Biologia Celular e Molecular, Porto, Portugal
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- Departamento de Patologia Clínica, Centro Hospitalar Universitário São João, Porto, Portugal
| | - Florian Grahammer
- 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
| | - Carlos Reguenga
- Unidade de Biologia Experimental, Departamento de Biomedicina, FMUP - Faculdade de Medicina da Universidade do Porto, Porto, Portugal
- Pain Neurobiology, IBMC - Instituto de Biologia Celular e Molecular, Porto, Portugal
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Filipe Almeida Monteiro
- Unidade de Biologia Experimental, Departamento de Biomedicina, FMUP - Faculdade de Medicina da Universidade do Porto, Porto, Portugal.
- Pain Neurobiology, IBMC - Instituto de Biologia Celular e Molecular, Porto, Portugal.
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.
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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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Togashi H, Davis SR, Sato M. From soap bubbles to multicellular organisms: Unraveling the role of cell adhesion and physical constraints in tile pattern formation and tissue morphogenesis. Dev Biol 2024; 506:1-6. [PMID: 37995916 DOI: 10.1016/j.ydbio.2023.11.007] [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: 05/22/2023] [Revised: 11/13/2023] [Accepted: 11/17/2023] [Indexed: 11/25/2023]
Abstract
Tile patterns, in which numerous cells are arranged in a regular pattern, are found in a variety of multicellular organisms and play important functional roles. Such regular arrangements of cells are regulated by various cell adhesion molecules. On the other hand, cell shape is also known to be regulated by physical constraints similar to those of soap bubbles. In particular, circumference minimization plays an important role, and cell adhesion negatively affects this process, thereby regulating tissue morphogenesis based on physical properties. Here, we focus on the Drosophila compound eye and the mouse auditory epithelium, and summarize the mechanisms of tile pattern formation by cell adhesion molecules such as cadherins, Irre Cell Recognition Modules (IRMs), and nectins. Phenomena that cannot be explained by physical stability based on cortical tension alone have been reported in the tile pattern formation in the compound eye, suggesting that previously unexplored forces such as cellular concentric expansion force may play an important role. We would like to summarize perspectives for future research on the mechanisms of tissue morphogenesis.
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Affiliation(s)
- Hideru Togashi
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe 657-8501, Japan
| | - Steven Ray Davis
- Mathematical Neuroscience Unit, Institute for Frontier Science Initiative, Graduate School of Medical Sciences, Kanazawa University, 13-1 Takaramachi, Kanazawa, Ishikawa, 920-8640, Japan
| | - Makoto Sato
- Mathematical Neuroscience Unit, Institute for Frontier Science Initiative, Graduate School of Medical Sciences, Kanazawa University, 13-1 Takaramachi, Kanazawa, Ishikawa, 920-8640, Japan.
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7
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Wang T, Chen S, Wang Z, Li S, Fei X, Wang T, Zhang M. KIRREL promotes the proliferation of gastric cancer cells and angiogenesis through the PI3K/AKT/mTOR pathway. J Cell Mol Med 2024; 28:e18020. [PMID: 37909722 PMCID: PMC10805501 DOI: 10.1111/jcmm.18020] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 10/14/2023] [Accepted: 10/19/2023] [Indexed: 11/03/2023] Open
Abstract
Anti-angiogenesis is a promising therapeutic strategy for delaying tumour progression that offers, new hope for gastric cancer targeted therapy. The purpose of this study was to investigate the precise mechanism by which Kin of IRRE-like protein 1 (KIRREL) contributes to the development of gastric cancer, particularly in terms of tumour angiogenesis. Differential expression of KIRREL in tissues and cells was detected using quantitative real-time polymerase chain reaction, western blotting and immunohistochemistry. A bioinformatics analysis was conducted to screen for the function and pathway enrichment of KIRREL in gastric cancer. Lentivirus-induced KIRREL silencing in SNU-5 cells and lentivirus-induced KIRREL overexpression in AGS cells were used to study the effect of KIRREL on the proliferation, cell cycle and angiogenesis of gastric cancer cells. Moreover, the expressions of PI3K, P-PI3K, AKT, P-AKT, mTOR, P-mTOR, HIF-1α and VEGF were also detected. Gastric cancer tissues and cells had high levels of KIRREL expression, which is associated with the proliferation, cell cycle and angiogenesis of gastric cancer cells. After silencing and overexpressing KIRREL in SNU-5 and AGS cells, respectively, the proliferation and angiogenesis of SNU-5 cells were inhibited, while the proliferation and angiogenesis of AGS cells were promoted. According to a bioinformatics analysis of the KIRREL gene, angiogenesis regulation and the PI3K/AKT pathway were highly connected. The PI3K/AKT/mTOR pathway was repressed and stimulated by KIRREL silencing and overexpression, respectively. IGF-1, an AKT agonist, and LY294002, an inhibitor, reversed the effects of KIRREL silencing and overexpression on the PI3K/AKT/mTOR pathway and on gastric cancer cell proliferation and angiogenesis. KIRREL may mediate the proliferation and angiogenesis of gastric cancer cells through the PI3K/AKT/mTOR signalling pathway. These findings could help in the further development of potential anti-angiogenesis targets.
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Affiliation(s)
- Tao Wang
- Department of OncologyThe Second Affiliated Hospital of Anhui Medical UniversityHefeiAnhuiChina
| | - Shuo Chen
- Department of OncologyThe Second Affiliated Hospital of Anhui Medical UniversityHefeiAnhuiChina
| | - Ziliang Wang
- Department of OncologyThe Second Affiliated Hospital of Anhui Medical UniversityHefeiAnhuiChina
| | - Siyu Li
- Department of OncologyThe Second Affiliated Hospital of Anhui Medical UniversityHefeiAnhuiChina
| | - Xichang Fei
- Department of OncologyThe Second Affiliated Hospital of Anhui Medical UniversityHefeiAnhuiChina
| | - Tong Wang
- Department of General PracticeThe Second Affiliated Hospital of Anhui Medical UniversityHefeiAnhuiChina
| | - Mingjun Zhang
- Department of OncologyThe Second Affiliated Hospital of Anhui Medical UniversityHefeiAnhuiChina
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8
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Kameyama T, Miyata M, Shiotani H, Adachi J, Kakuta S, Uchiyama Y, Mizutani K, Takai Y. Heterogeneity of perivascular astrocyte endfeet depending on vascular regions in the mouse brain. iScience 2023; 26:108010. [PMID: 37829206 PMCID: PMC10565786 DOI: 10.1016/j.isci.2023.108010] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 07/14/2023] [Accepted: 09/18/2023] [Indexed: 10/14/2023] Open
Abstract
Astrocytes interact with not only synapses but also brain blood vessels through perivascular astrocyte endfeet (PV-AEF) to form the neurovascular unit (NVU). However, PV-AEF components have not been fully identified. Here, we biochemically isolated blood vessels from mouse brain homogenates and purified PV-AEF. The purified PV-AEF were observed in different sizes, similar to PV-AEF on brain blood vessels. Mass spectrometry analysis identified 9,762 proteins in the purified PV-AEF, including cell adhesion molecules, nectin-2δ, Kirrel2, and podoplanin. Immunofluorescence microscopic analysis revealed that nectin-2δ and podoplanin were concentrated mainly in arteries/arterioles and veins/venules of the mouse brain, whereas Kirrel2 was mainly in arteries/arterioles. Nectin-2α/δ, Kirrel2, and podoplanin were preferentially observed in large sizes of the purified PV-AEF. Furthermore, Kirrel2 potentially has cell adhesion activity of cultured astrocytes. Collectively, these results indicate that PV-AEF have heterogeneity in sizes and molecular components, implying different roles of PV-AEF in NVU function depending on vascular regions.
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Affiliation(s)
- Takeshi Kameyama
- Division of Pathogenetic Signaling, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe 650-0047, Japan
- Department of Immunology and Parasitology, Graduate School of Medicine, Tokushima University, Tokushima 770-8503, Japan
| | - Muneaki Miyata
- Division of Pathogenetic Signaling, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe 650-0047, Japan
- Division of Pathogenetic Signaling, Institute of Advanced Medical Sciences, Tokushima University, Tokushima 770-8503, Japan
| | - Hajime Shiotani
- Division of Pathogenetic Signaling, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe 650-0047, Japan
- Division of Pathogenetic Signaling, Institute of Advanced Medical Sciences, Tokushima University, Tokushima 770-8503, Japan
| | - Jun Adachi
- Laboratory of Proteomics for Drug Discovery, Center for Drug Design Research, National Institute of Biomedical Innovation, Health and Nutrition, Osaka 567-0085, Japan
- Laboratory of Clinical and Analytical Chemistry, Center for Drug Design Research, National Institute of Biomedical Innovation, Health and Nutrition, Osaka 567-0085, Japan
| | - Soichiro Kakuta
- Laboratory of Morphology and Image Analysis, Biomedical Research Core Facilities, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
- Department of Cellular Molecular Neuropathology, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
| | - Yasuo Uchiyama
- Department of Cellular Molecular Neuropathology, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
| | - Kiyohito Mizutani
- Division of Pathogenetic Signaling, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe 650-0047, Japan
- Division of Pathogenetic Signaling, Institute of Advanced Medical Sciences, Tokushima University, Tokushima 770-8503, Japan
| | - Yoshimi Takai
- Division of Pathogenetic Signaling, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe 650-0047, Japan
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9
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Gerlach GF, Imseis ZH, Cooper SL, Santos AN, O’Brien LL. Mapping of the podocin proximity-dependent proteome reveals novel components of the kidney podocyte foot process. Front Cell Dev Biol 2023; 11:1195037. [PMID: 37325559 PMCID: PMC10262054 DOI: 10.3389/fcell.2023.1195037] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 05/03/2023] [Indexed: 06/17/2023] Open
Abstract
Introduction: The unique architecture of glomerular podocytes is integral to kidney filtration. Interdigitating foot processes extend from the podocyte cell body, wrap around fenestrated capillaries, and form specialized junctional complexes termed slit diaphragms to create a molecular sieve. However, the full complement of proteins which maintain foot process integrity, and how this localized proteome changes with disease, remain to be elucidated. Methods: Proximity-dependent biotin identification (BioID) enables the identification of spatially localized proteomes. To this end, we developed a novel in vivo BioID knock-in mouse model. We utilized the slit diaphragm protein podocin (Nphs2) to create a podocin-BioID fusion. Podocin-BioID localizes to the slit diaphragm, and biotin injection leads to podocyte-specific protein biotinylation. We isolated the biotinylated proteins and performed mass spectrometry to identify proximal interactors. Results and Discussion: Gene ontology analysis of 54 proteins specifically enriched in our podocin-BioID sample revealed 'cell junctions,' 'actin binding,' and 'cytoskeleton organization' as top terms. Known foot process components were identified, and we further uncovered two novel proteins: the tricellular junctional protein Ildr2 and the CDC42 and N-WASP interactor Fnbp1l. We confirmed that Ildr2 and Fnbp1l are expressed by podocytes and partially colocalize with podocin. Finally, we investigated how this proteome changes with age and uncovered a significant increase in Ildr2. This was confirmed by immunofluorescence on human kidney samples and suggests altered junctional composition may preserve podocyte integrity. Together, these assays have led to new insights into podocyte biology and support the efficacy of utilizing BioID in vivo to interrogate spatially localized proteomes in health, aging, and disease.
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Affiliation(s)
| | | | | | | | - Lori L. O’Brien
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
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10
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Ho SWT, Sheng T, Xing M, Ooi WF, Xu C, Sundar R, Huang KK, Li Z, Kumar V, Ramnarayanan K, Zhu F, Srivastava S, Isa ZFBA, Anene-Nzelu CG, Razavi-Mohseni M, Shigaki D, Ma H, Tan ALK, Ong X, Lee MH, Tay ST, Guo YA, Huang W, Li S, Beer MA, Foo RSY, Teh M, Skanderup AJ, Teh BT, Tan P. Regulatory enhancer profiling of mesenchymal-type gastric cancer reveals subtype-specific epigenomic landscapes and targetable vulnerabilities. Gut 2023; 72:226-241. [PMID: 35817555 DOI: 10.1136/gutjnl-2021-326483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 06/03/2022] [Indexed: 01/28/2023]
Abstract
OBJECTIVE Gastric cancer (GC) comprises multiple molecular subtypes. Recent studies have highlighted mesenchymal-subtype GC (Mes-GC) as a clinically aggressive subtype with few treatment options. Combining multiple studies, we derived and applied a consensus Mes-GC classifier to define the Mes-GC enhancer landscape revealing disease vulnerabilities. DESIGN Transcriptomic profiles of ~1000 primary GCs and cell lines were analysed to derive a consensus Mes-GC classifier. Clinical and genomic associations were performed across >1200 patients with GC. Genome-wide epigenomic profiles (H3K27ac, H3K4me1 and assay for transposase-accessible chromatin with sequencing (ATAC-seq)) of 49 primary GCs and GC cell lines were generated to identify Mes-GC-specific enhancer landscapes. Upstream regulators and downstream targets of Mes-GC enhancers were interrogated using chromatin immunoprecipitation followed by sequencing (ChIP-seq), RNA sequencing, CRISPR/Cas9 editing, functional assays and pharmacological inhibition. RESULTS We identified and validated a 993-gene cancer-cell intrinsic Mes-GC classifier applicable to retrospective cohorts or prospective single samples. Multicohort analysis of Mes-GCs confirmed associations with poor patient survival, therapy resistance and few targetable genomic alterations. Analysis of enhancer profiles revealed a distinctive Mes-GC epigenomic landscape, with TEAD1 as a master regulator of Mes-GC enhancers and Mes-GCs exhibiting preferential sensitivity to TEAD1 pharmacological inhibition. Analysis of Mes-GC super-enhancers also highlighted NUAK1 kinase as a downstream target, with synergistic effects observed between NUAK1 inhibition and cisplatin treatment. CONCLUSION Our results establish a consensus Mes-GC classifier applicable to multiple transcriptomic scenarios. Mes-GCs exhibit a distinct epigenomic landscape, and TEAD1 inhibition and combinatorial NUAK1 inhibition/cisplatin may represent potential targetable options.
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Affiliation(s)
- Shamaine Wei Ting Ho
- Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore.,Cancer Science Institute of Singapore, National University of Singapore, Singapore.,Cancer and Stem Cell Biology Program, Duke-NUS Medical School, Singapore
| | - Taotao Sheng
- Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore.,Cancer and Stem Cell Biology Program, Duke-NUS Medical School, Singapore.,Department of Biochemistry, National University of Singapore, Singapore
| | - Manjie Xing
- Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore.,Cancer and Stem Cell Biology Program, Duke-NUS Medical School, Singapore
| | - Wen Fong Ooi
- Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore
| | - Chang Xu
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School, Singapore
| | - Raghav Sundar
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School, Singapore.,Department of Haematology-Oncology, National University Cancer Institute, National University Hospital, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,The N.1 Institute for Health, National University of Singapore, Singapore.,Singapore Gastric Cancer Consortium, Singapore
| | - Kie Kyon Huang
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School, Singapore
| | - Zhimei Li
- Laboratory of Cancer Epigenome, Division of Medical Sciences, National Cancer Centre Singapore, Singapore
| | - Vikrant Kumar
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School, Singapore
| | | | - Feng Zhu
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Supriya Srivastava
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | | | - Chukwuemeka George Anene-Nzelu
- Cardiovascular Research Institute, National University Health System, Singapore.,Human Genetics, Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore.,Montreal Heart Institute, Quebec, Quebec, Canada.,Department of Medicine, University of Montreal, Quebec, Quebec, Canada
| | - Milad Razavi-Mohseni
- Department of Biomedical Engineering and McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Dustin Shigaki
- Department of Biomedical Engineering and McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Haoran Ma
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School, Singapore
| | - Angie Lay Keng Tan
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School, Singapore
| | - Xuewen Ong
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School, Singapore
| | - Ming Hui Lee
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School, Singapore
| | - Su Ting Tay
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School, Singapore
| | - Yu Amanda Guo
- Computational and Systems Biology, Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore
| | - Weitai Huang
- Computational and Systems Biology, Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore
| | - Shang Li
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School, Singapore.,Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Michael A Beer
- Department of Biomedical Engineering and McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Roger Sik Yin Foo
- Cardiovascular Research Institute, National University Health System, Singapore.,Human Genetics, Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore
| | - Ming Teh
- Department of Pathology, National University of Singapore, Singapore
| | - Anders Jacobsen Skanderup
- Computational and Systems Biology, Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore
| | - Bin Tean Teh
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School, Singapore.,Laboratory of Cancer Epigenome, Division of Medical Sciences, National Cancer Centre Singapore, Singapore.,Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore
| | - Patrick Tan
- Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore .,Cancer Science Institute of Singapore, National University of Singapore, Singapore.,Cancer and Stem Cell Biology Program, Duke-NUS Medical School, Singapore.,Singapore Gastric Cancer Consortium, Singapore.,Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Cellular and Molecular Research, National Cancer Centre, Singapore.,SingHealth/Duke-NUS Institute of Precision Medicine, National Heart Centre Singapore, Singapore
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11
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Dorison A, Ghobrial I, Graham A, Peiris T, Forbes TA, See M, Das M, Saleem MA, Quinlan C, Lawlor KT, Ramialison M, Howden SE, Little MH. Kidney Organoids Generated Using an Allelic Series of NPHS2 Point Variants Reveal Distinct Intracellular Podocin Mistrafficking. J Am Soc Nephrol 2023; 34:88-109. [PMID: 36167728 PMCID: PMC10101587 DOI: 10.1681/asn.2022060707] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 08/31/2022] [Accepted: 09/06/2022] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND NPHS2 variants are the most common cause of steroid-resistant nephrotic syndrome in children >1 month old. Missense NPHS2 variants were reported to cause mistrafficking of the encoded protein, PODOCIN, but this conclusion was on the basis of overexpression in some nonpodocyte cell lines. METHODS We generated a series of human induced pluripotent stem cell (iPSC) lines bearing pathogenic missense variants of NPHS2 , encoding the protein changes p.G92C, p.P118L, p.R138Q, p.R168H, and p.R291W, and control lines. iPSC lines were also generated from a patient with steroid-resistant nephrotic syndrome (p.R168H homozygote) and a healthy heterozygous parent. All lines were differentiated into kidney organoids. Immunofluorescence assessed PODOCIN expression and subcellular localization. Podocytes were transcriptionally profiled and PODOCIN-NEPHRIN interaction interrogated. RESULTS All variant lines revealed reduced levels of PODOCIN protein in the absence of reduced transcription. Although wild-type PODOCIN localized to the membrane, distinct variant proteins displayed unique patterns of subcellular protein trafficking, some unreported. P118L and R138Q were preferentially retained in the endoplasmic reticulum (ER); R168H and R291W accumulated in the Golgi. Podocyte profiling demonstrated minimal disease-associated transcriptional change. All variants displayed podocyte-specific apoptosis, which was not linked to ER stress. NEPHRIN-PODOCIN colocalization elucidated the variant-specific effect on NEPHRIN association and hence NEPHRIN trafficking. CONCLUSIONS Specific variants of endogenous NPHS2 result in distinct subcellular PODOCIN localization within organoid podocytes. Understanding the effect of each variant on protein levels and localization and the effect on NEPHRIN provides additional insight into the pathobiology of NPHS2 variants. PODCAST This article contains a podcast at https://dts.podtrac.com/redirect.mp3/www.asn-online.org/media/podcast/JASN/2023_01_05_JASN2022060707.mp3.
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Affiliation(s)
- Aude Dorison
- Murdoch Children’s Research Institute, Melbourne, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Australia
- Novo Nordisk Foundation Centre for Stem Cell Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Irene Ghobrial
- Murdoch Children’s Research Institute, Melbourne, Australia
| | - Alison Graham
- Murdoch Children’s Research Institute, Melbourne, Australia
| | | | - Thomas A. Forbes
- Murdoch Children’s Research Institute, Melbourne, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Australia
- Royal Children’s Hospital, Melbourne, Australia
| | - Michael See
- Murdoch Children’s Research Institute, Melbourne, Australia
- Monash Bioinformatics Platform, Monash University, Clayton, Australia
| | - Mithun Das
- Murdoch Children’s Research Institute, Melbourne, Australia
| | - Moin A. Saleem
- Department of Paediatric Nephrology, Bristol Royal Hospital for Children, Bristol, United Kingdom
| | - Catherine Quinlan
- Murdoch Children’s Research Institute, Melbourne, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Australia
- Royal Children’s Hospital, Melbourne, Australia
| | - Kynan T. Lawlor
- Murdoch Children’s Research Institute, Melbourne, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Australia
- Novo Nordisk Foundation Centre for Stem Cell Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Mirana Ramialison
- Murdoch Children’s Research Institute, Melbourne, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Australia
- Novo Nordisk Foundation Centre for Stem Cell Medicine, University of Copenhagen, Copenhagen, Denmark
- Australian Regenerative Medicine Institute, Clayton, Australia
| | - Sara E. Howden
- Murdoch Children’s Research Institute, Melbourne, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Australia
- Novo Nordisk Foundation Centre for Stem Cell Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Melissa H. Little
- Murdoch Children’s Research Institute, Melbourne, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Australia
- Novo Nordisk Foundation Centre for Stem Cell Medicine, University of Copenhagen, Copenhagen, Denmark
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12
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Lee Y, Wang M, Imamura K, Sato M. Quantitative analysis of the roles of IRM cell adhesion molecules in column formation in the fly brain. Dev Growth Differ 2023; 65:37-47. [PMID: 36534021 DOI: 10.1111/dgd.12834] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 11/20/2022] [Accepted: 11/25/2022] [Indexed: 12/23/2022]
Abstract
The Drosophila visual center shows columnar structures, basic structural and functional units of the brain, that are shared with the mammalian cerebral cortex. Visual information received in the ommatidia in the compound eye is transmitted to the columns in the brain. However, the developmental mechanisms of column formation are largely unknown. The Irre Cell Recognition Module (IRM) proteins are a family of immunoglobulin cell adhesion molecules. The four Drosophila IRM proteins are localized to the developing columns, the structure of which is affected in IRM mutants, suggesting that IRM proteins are essential for column formation. Since IRM proteins are cell adhesion molecules, they may regulate cell adhesion between columnar neurons. To test this possibility, we specifically knocked down IRM genes in columnar neurons and examined the defects in column formation. We developed a system that automatically extracts the individual column images and quantifies the column shape. Using this system, we demonstrated that IRM genes play critical roles in regulating column shape in a core columnar neuron, Mi1. We also show that their expression in the other columnar neurons, Mi4 and T4/5, is essential, suggesting that the interactions between IRM proteins and multiple neurons shape the columns in the fly brain.
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Affiliation(s)
- Yunfei Lee
- Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Miaoxing Wang
- Mathematical Neuroscience Unit, Institute for Frontier Science Initiative, Kanazawa, Japan
| | - Kousuke Imamura
- Faculty of Electrical, Information and Communication Engineering, Institute of Science and Engineering, Kanazawa University, Kanazawa, Japan
| | - Makoto Sato
- Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan.,Mathematical Neuroscience Unit, Institute for Frontier Science Initiative, Kanazawa, Japan
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13
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Wang C, Feng X, Su D, Chen Z, Wang S, Tang M, Huang M, Nie L, Zhang H, Li S, Yin L, Johnson RL, Hart T, Chen J. Integrated screens uncover a cell surface tumor suppressor gene KIRREL involved in Hippo pathway. Proc Natl Acad Sci U S A 2022; 119:e2121779119. [PMID: 35704761 PMCID: PMC9231494 DOI: 10.1073/pnas.2121779119] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 05/12/2022] [Indexed: 01/07/2023] Open
Abstract
Cell surface proteins play essential roles in various biological processes and are highly related to cancer development. They also serve as important markers for cell identity and targets for pharmacological intervention. Despite their great potentials in biomedical research, comprehensive functional analysis of cell surface proteins remains scarce. Here, with a de novo designed library targeting cell surface proteins, we performed in vivo CRISPR screens to evaluate the effects of cell surface proteins on tumor survival and proliferation. We found that Kirrel1 loss markedly promoted tumor growth in vivo. Moreover, KIRREL was significantly enriched in a separate CRISPR screen based on a specific Hippo pathway reporter. Further studies revealed that KIRREL binds directly to SAV1 to activate the Hippo tumor suppressor pathway. Together, our integrated screens reveal a cell surface tumor suppressor involved in the Hippo pathway and highlight the potential of these approaches in biomedical research.
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Affiliation(s)
- Chao Wang
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX
| | - Xu Feng
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX
| | - Dan Su
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX
| | - Zhen Chen
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX
| | - Shimin Wang
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX
| | - Mengfan Tang
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX
| | - Min Huang
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX
| | - Litong Nie
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX
| | - Huimin Zhang
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX
| | - Siting Li
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX
| | - Ling Yin
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX
| | - Randy L. Johnson
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, TX
| | - Traver Hart
- Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, TX
| | - Junjie Chen
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX
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14
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Kostovska I, Trajkovska KT, Topuzovska S, Cekovska S, Labudovic D, Kostovski O, Spasovski G. Nephrinuria and podocytopathies. Adv Clin Chem 2022; 108:1-36. [PMID: 35659057 DOI: 10.1016/bs.acc.2021.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The discovery of nephrin in 1998 has launched a new era in glomerular diseases research, emphasizing its crucial role in the structure and function of the glomerular filtration barrier. In the past 20 years, substantial advances have been made in understanding podocyte structure and function as well as the discovery of several podocyte-related proteins including nephrin. The glomerular filtration barrier is comprised of podocytes, the glomerular basement membrane and endothelial cells. Podocytes, with their specialized slit diaphragm, form the essential backbone of the glomerular filtration barrier. Nephrin is a crucial structural and functional feature of the slit diaphragm that prevents plasma protein, blood cell and macromolecule leakage into the urine. Podocyte damage results in nephrin release. Podocytopathies are kidney diseases in which podocyte damage drives proteinuria, i.e., nephrotic syndrome. Many kidney diseases involve podocytopathy including congenital nephrotic syndrome of Finnish type, diffuse mesangial sclerosis, minimal change disease, focal segmental glomerulosclerosis, collapsing glomerulonephropathy, diabetic nephropathy, lupus nephropathy, hypertensive nephropathy and preeclampsia. Recently, urinary nephrin measurement has become important in the early detection of podocytopathies. In this chapter, we elaborate the main structural and functional features of nephrin as a podocyte-specific protein, pathomechanisms of podocytopathies which result in nephrinuria, highlight the most commonly used methods for detecting urinary nephrin and investigate the diagnostic, prognostic and potential therapeutic relevance of urinary nephrin in primary and secondary proteinuric kidney diseases.
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Affiliation(s)
- Irena Kostovska
- Department of Medical and Experimental Biochemistry, Faculty of Medicine, Ss. Cyril and Methodius University, Skopje, North Macedonia.
| | - Katerina Tosheska Trajkovska
- Department of Medical and Experimental Biochemistry, Faculty of Medicine, Ss. Cyril and Methodius University, Skopje, North Macedonia
| | - Sonja Topuzovska
- Department of Medical and Experimental Biochemistry, Faculty of Medicine, Ss. Cyril and Methodius University, Skopje, North Macedonia
| | - Svetlana Cekovska
- Department of Medical and Experimental Biochemistry, Faculty of Medicine, Ss. Cyril and Methodius University, Skopje, North Macedonia
| | - Danica Labudovic
- Department of Medical and Experimental Biochemistry, Faculty of Medicine, Ss. Cyril and Methodius University, Skopje, North Macedonia
| | - Ognen Kostovski
- University Clinic of Abdominal Surgery, Faculty of Medicine, Ss. Cyril and Methodius University, Skopje, North Macedonia
| | - Goce Spasovski
- University Clinic of Nephrology, Faculty of Medicine, Ss. Cyril and Methodius University, Skopje, North Macedonia
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15
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Dandapani MC, Venkatesan V, Charmine P, Geminiganesan S, Ekambaram S. Differential urinary microRNA expression analysis of miR-1, miR-215, miR-335, let-7a in childhood nephrotic syndrome. Mol Biol Rep 2022; 49:6591-6600. [PMID: 35553329 DOI: 10.1007/s11033-022-07500-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Accepted: 04/21/2022] [Indexed: 10/18/2022]
Abstract
BACKGROUND Recently, urinary exosomal miRNAs are gaining increasing attention as their expression profiles are often associated with specific diseases and they exhibit great potential as noninvasive biomarkers for the diagnosis of various diseases. The present study was aimed to evaluate the expression status of selected miRNAs (miR-1, miR-215-5p, miR-335-5p and let-7a-5p) in urine samples from children with NS [steroid sensitive (SSNS)] and [steroid resistant (SRNS)] along with healthy control group. METHODS MicroRNA isolation was carried out in urine samples collected from SSNS (100 nos), SRNS (100 nos), and healthy controls (50 nos) using MiRNeasy Mini Kit, followed by cDNA conversion for all the four selected miRNAs using Taqman advanced miRNA cDNA synthesis kit and their expression was quantified by Taqman Advanced miRNA assay kits using Real Time PCR Machine and Rotogen-Q in SSNS and SRNS patients and healthy control subjects. RESULTS Quantification of all the four miRNAs (miR-1, mir-215, miR-335, let-7a) were found to be upregulated in both SSNS and SRNS as compared to control group. Further, the comparison of microRNAs within the case groups revealed significant downregulation of three microRNAs-miR-1, miR-215, miR- 335 and upregulation of let-7a in SRNS group as compared to SSNS. The t-test performed for all the four miRNAs was found to be statistically significant. CONCLUSIONS The aberrant expression of all the four microRNAs in both SSNS and SRNS as compared to healthy subjects may serve as novel biomarkers to distinguish between NS and healthy controls. The differential expression of microRNA let-7a is useful to discriminate SSNS and SRNS.
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Affiliation(s)
- Mohanapriya Chinambedu Dandapani
- Central Research Facility, Faculty of Clinical Research, Sri Ramachandra Institute of Higher Education and Research, No.1 Ramachandra Nagar, Porur, Chennai, Tamil Nadu, 600 116, India.
| | - Vettriselvi Venkatesan
- Department of Human Genetics, Sri Ramachandra Institute of Higher Education and Research, Porur, Chennai, 600 116, India
| | - Pricilla Charmine
- Central Research Facility, Faculty of Clinical Research, Sri Ramachandra Institute of Higher Education and Research, No.1 Ramachandra Nagar, Porur, Chennai, Tamil Nadu, 600 116, India
| | - Sangeetha Geminiganesan
- Department of Pediatric Medicine, Sri Ramachandra Institute of Higher Education and Research, Porur, Chennai, 600 116, India
| | - Sudha Ekambaram
- Department of Pediatric Nephrology, Dr. Mehta's Hospital, Chetpet, Chennai, 600031, India
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16
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Woznowski MP, Potthoff SA, Königshausen E, Haase R, Hoch H, Meyer-Schwesinger C, Wiech T, Stegbauer J, Rump LC, Sellin L, Quack I. Inhibition of p38 MAPK decreases hyperglycemia-induced nephrin endocytosis and attenuates albuminuria. J Mol Med (Berl) 2022; 100:781-795. [PMID: 35451598 PMCID: PMC9110524 DOI: 10.1007/s00109-022-02184-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 01/20/2022] [Accepted: 02/22/2022] [Indexed: 11/26/2022]
Abstract
Abstract Chronic hyperglycemia, as in diabetes mellitus, may cause glomerular damage with microalbuminuria as an early sign. Noteworthy, even acute hyperglycemia can increase glomerular permeability before structural damage of the glomerular filter can be detected. Despite intensive research, specific antiproteinuric therapy is not available so far. Thus, a deeper understanding of the molecular mechanisms of albuminuria is desirable. P38 MAPK signaling is involved in the development of hyperglycemia-induced albuminuria. However, the mechanism of increased p38 MAPK activity leading to increased permeability and albuminuria remained unclear. Recently, we demonstrated that acute hyperglycemia triggers endocytosis of nephrin, the key molecule of the slit diaphragm, and induces albuminuria. Here, we identify p38 MAPK as a pivotal regulator of hyperglycemia-induced nephrin endocytosis. Activated p38 MAPK phosphorylates the nephrin c-terminus at serine 1146, facilitating the interaction of PKCα with nephrin. PKCα phosphorylates nephrin at threonine residues 1120 and 1125, mediating the binding of β-arrestin2 to nephrin. β-arrestin2 triggers endocytosis of nephrin by coupling it to the endocytic machinery, leading to increased glomerular permeability. Pharmacological inhibition of p38 MAPK preserves nephrin surface expression and significantly attenuates albuminuria. Key messages Acute hyperglycemia triggers endocytosis of nephrin. Activated p38 MAPK phosphorylates the nephrin c-terminus at serine 1146, facilitating the interaction of PKCα with nephrin. PKCα phosphorylates nephrin at threonine residues 1120 and 1125, mediating the binding of β-arrestin2 to nephrin. β-arrestin2 triggers endocytosis of nephrin by coupling it to the endocytic machinery, leading to a leaky glomerular filter. Pharmacological inhibition of p38 MAPK preserves nephrin surface expression and significantly attenuates albuminuria under hyperglycemic conditions.
Supplementary Information The online version contains supplementary material available at 10.1007/s00109-022-02184-5.
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Affiliation(s)
| | | | - Eva Königshausen
- Department of Nephrology, Medical Faculty, Heinrich-Heine University, 40225, Düsseldorf, Germany
| | - Raphael Haase
- Department of Nephrology, Medical Faculty, Heinrich-Heine University, 40225, Düsseldorf, Germany
| | - Henning Hoch
- Department of Nephrology, Medical Faculty, Heinrich-Heine University, 40225, Düsseldorf, Germany
| | - Catherine Meyer-Schwesinger
- Institute of Cellular and Integrative Physiology, University Clinic Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Thorsten Wiech
- Institute of Pathology, Nephropathology Section, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Johannes Stegbauer
- Department of Nephrology, Medical Faculty, Heinrich-Heine University, 40225, Düsseldorf, Germany
| | - Lars Christian Rump
- Department of Nephrology, Medical Faculty, Heinrich-Heine University, 40225, Düsseldorf, Germany
| | - Lorenz Sellin
- Department of Nephrology, Medical Faculty, Heinrich-Heine University, 40225, Düsseldorf, Germany
| | - Ivo Quack
- Emergency Department, Klinikum Konstanz, 78464, Konstanz, Germany
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17
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Paul A, Annunziato S, Lu B, Sun T, Evrova O, Planas-Paz L, Orsini V, Terracciano LM, Charlat O, Loureiro ZY, Ji L, Zamponi R, Sigoillot F, Lei H, Lindeman A, Russ C, Reece-Hoyes JS, Nicholson TB, Tchorz JS, Cong F. Cell adhesion molecule KIRREL1 is a feedback regulator of Hippo signaling recruiting SAV1 to cell-cell contact sites. Nat Commun 2022; 13:930. [PMID: 35177623 PMCID: PMC8854406 DOI: 10.1038/s41467-022-28567-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 01/31/2022] [Indexed: 12/11/2022] Open
Abstract
The Hippo/YAP pathway controls cell proliferation through sensing physical and spatial organization of cells. How cell-cell contact is sensed by Hippo signaling is poorly understood. Here, we identified the cell adhesion molecule KIRREL1 as an upstream positive regulator of the mammalian Hippo pathway. KIRREL1 physically interacts with SAV1 and recruits SAV1 to cell-cell contact sites. Consistent with the hypothesis that KIRREL1-mediated cell adhesion suppresses YAP activity, knockout of KIRREL1 increases YAP activity in neighboring cells. Analyzing pan-cancer CRISPR proliferation screen data reveals KIRREL1 as the top plasma membrane protein showing strong correlation with known Hippo regulators, highlighting a critical role of KIRREL1 in regulating Hippo signaling and cell proliferation. During liver regeneration in mice, KIRREL1 is upregulated, and its genetic ablation enhances hepatic YAP activity, hepatocyte reprogramming and biliary epithelial cell proliferation. Our data suggest that KIRREL1 functions as a feedback regulator of the mammalian Hippo pathway through sensing cell-cell interaction and recruiting SAV1 to cell-cell contact sites.
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Affiliation(s)
- Atanu Paul
- Novartis Institutes for BioMedical Research, Novartis Pharma AG, Cambridge, MA, USA
| | - Stefano Annunziato
- Novartis Institutes for BioMedical Research, Novartis Pharma AG, Basel, Switzerland
| | - Bo Lu
- Novartis Institutes for BioMedical Research, Novartis Pharma AG, Cambridge, MA, USA
| | - Tianliang Sun
- Novartis Institutes for BioMedical Research, Novartis Pharma AG, Basel, Switzerland
| | - Olivera Evrova
- Novartis Institutes for BioMedical Research, Novartis Pharma AG, Basel, Switzerland
| | - Lara Planas-Paz
- Novartis Institutes for BioMedical Research, Novartis Pharma AG, Basel, Switzerland
| | - Vanessa Orsini
- Novartis Institutes for BioMedical Research, Novartis Pharma AG, Basel, Switzerland
| | - Luigi M Terracciano
- Department of Biomedical Sciences, Humanitas University, Pieve Emanuele (Milan), Italy.,IRCCS Humanitas Research Hospital, Rozzano (Milan), Italy
| | - Olga Charlat
- Novartis Institutes for BioMedical Research, Novartis Pharma AG, Cambridge, MA, USA
| | - Zinger Yang Loureiro
- Novartis Institutes for BioMedical Research, Novartis Pharma AG, Cambridge, MA, USA
| | - Lei Ji
- Novartis Institutes for BioMedical Research, Novartis Pharma AG, Cambridge, MA, USA
| | - Raffaella Zamponi
- Novartis Institutes for BioMedical Research, Novartis Pharma AG, Cambridge, MA, USA
| | - Frederic Sigoillot
- Novartis Institutes for BioMedical Research, Novartis Pharma AG, Cambridge, MA, USA
| | - Hong Lei
- Novartis Institutes for BioMedical Research, Novartis Pharma AG, Cambridge, MA, USA
| | - Alicia Lindeman
- Novartis Institutes for BioMedical Research, Novartis Pharma AG, Cambridge, MA, USA
| | - Carsten Russ
- Novartis Institutes for BioMedical Research, Novartis Pharma AG, Cambridge, MA, USA
| | - John S Reece-Hoyes
- Novartis Institutes for BioMedical Research, Novartis Pharma AG, Cambridge, MA, USA
| | - Thomas B Nicholson
- Novartis Institutes for BioMedical Research, Novartis Pharma AG, Cambridge, MA, USA
| | - Jan S Tchorz
- Novartis Institutes for BioMedical Research, Novartis Pharma AG, Basel, Switzerland
| | - Feng Cong
- Novartis Institutes for BioMedical Research, Novartis Pharma AG, Cambridge, MA, USA.
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18
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Zhang F, Liu J, Yu J, Sun W, Wang Y, Fan T, Sun Y, Han X. Effect of Nephropathy Prescription I on the Expression of Angptl3 and Podocyte-Associated Protein in Mice with Adriamycin-Induced Nephropathy. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE : ECAM 2022; 2022:9921679. [PMID: 38149181 PMCID: PMC10751164 DOI: 10.1155/2022/9921679] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 12/12/2021] [Accepted: 12/23/2021] [Indexed: 12/28/2023]
Abstract
Objective This study aimed to investigate the effects of Nephropathy Prescription I on the expression of angptl3, nephrin, and podocin, in addition to its protective effects on podocytes in mice with adriamycin-induced nephropathy. Methods BALB/c mice were randomly divided into the control (C), adriamycin (Model or M), adriamycin + Nephropathy Prescription I (M + Z), adriamycin + prednisone acetate (M + S), and adriamycin + Nephropathy Prescription I + prednisone acetate groups (M + Z + S). All mice except those in the C group in the experimental groups were treated with a single tail vein injection of adriamycin. The urine albumin-creatinine ratio was measured before model establishment and on the 7th day, 14th day, 21st day, and 28th day of doxorubicin injection. All the mice were sacrificed on the 29th day. Blood samples were collected to observe biochemical indicators in the serum. The morphological structure and podocyte ultrastructure in the kidney were observed using light and electron microscopy, respectively. The expression of angptl3, nephrin, and podocin at the mRNA and protein levels was detected by real-time PCR and western blotting, respectively. Results Following modeling with adriamycin, albuminuria was observed in urine samples in the first week, and the urinary protein/creatinine ratio increased maximally in the fourth week in the M group (P < 0.05). In contrast, the urinary protein/creatinine ratio significantly decreased (P < 0.05) in the third week in the (M + Z) group compared to that in the M group. Similarly, this ratio decreased in the (M + S) and (M + Z + S) groups compared to that in the M group throughout the experiment. Compared with the C group, serum albumin content and the expression of nephrin and podocin decreased (P < 0.05), whereas blood lipid level and the expression of angptl3 increased (P < 0.05) in the M group. Glomerular foot process fusion was observed in this group using electron microscopy. In all the intervention groups, serum albumin content and the expression of nephrin and podocin increased (P < 0.05), whereas blood lipid level and the expression of angptl3 decreased (P < 0.05), with alleviated glomerular foot process injury observed particularly in the (M + Z + S) group. Conclusion The Nephropathy Prescription I can alleviate albuminuria, increase serum albumin levels, lower blood lipid levels, and reduce the fusion of foot processes of podocytes in mice with adriamycin-induced nephropathy. The protective effects of the Nephropathy Prescription I may function by reducing Angptl3 expression and increasing nephrin and podocin expression.
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Affiliation(s)
- Feifei Zhang
- Children's Hosptial of Fudan University Department of Traditional Chinese Medicine, Shanghai 201102, China
| | - Junchao Liu
- Children's Hosptial of Fudan University Department of Traditional Chinese Medicine, Shanghai 201102, China
| | - Jian Yu
- Children's Hosptial of Fudan University Department of Traditional Chinese Medicine, Shanghai 201102, China
| | - Wen Sun
- Children's Hosptial of Fudan University Department of Traditional Chinese Medicine, Shanghai 201102, China
| | - Yonghong Wang
- Children's Hosptial of Fudan University Department of Traditional Chinese Medicine, Shanghai 201102, China
| | - Teng Fan
- Children's Hosptial of Fudan University Department of Traditional Chinese Medicine, Shanghai 201102, China
| | - Yanyan Sun
- Children's Hosptial of Fudan University Department of Traditional Chinese Medicine, Shanghai 201102, China
| | - Xinghui Han
- Children's Hosptial of Fudan University Department of Traditional Chinese Medicine, Shanghai 201102, China
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Agarwal S, Sudhini YR, Polat OK, Reiser J, Altintas MM. Renal cell markers: lighthouses for managing renal diseases. Am J Physiol Renal Physiol 2021; 321:F715-F739. [PMID: 34632812 DOI: 10.1152/ajprenal.00182.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Kidneys, one of the vital organs in our body, are responsible for maintaining whole body homeostasis. The complexity of renal function (e.g., filtration, reabsorption, fluid and electrolyte regulation, and urine production) demands diversity not only at the level of cell types but also in their overall distribution and structural framework within the kidney. To gain an in depth molecular-level understanding of the renal system, it is imperative to discern the components of kidney and the types of cells residing in each of the subregions. Recent developments in labeling, tracing, and imaging techniques have enabled us to mark, monitor, and identify these cells in vivo with high efficiency in a minimally invasive manner. In this review, we summarize different cell types, specific markers that are uniquely associated with those cell types, and their distribution in the kidney, which altogether make kidneys so special and different. Cellular sorting based on the presence of certain proteins on the cell surface allowed for the assignment of multiple markers for each cell type. However, different studies using different techniques have found contradictions in cell type-specific markers. Thus, the term "cell marker" might be imprecise and suboptimal, leading to uncertainty when interpreting the data. Therefore, we strongly believe that there is an unmet need to define the best cell markers for a cell type. Although the compendium of renal-selective marker proteins presented in this review is a resource that may be useful to researchers, we acknowledge that the list may not be necessarily exhaustive.
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Affiliation(s)
- Shivangi Agarwal
- Department of Internal Medicine, Rush University, Chicago, Illinois
| | | | - Onur K Polat
- Department of Internal Medicine, Rush University, Chicago, Illinois
| | - Jochen Reiser
- Department of Internal Medicine, Rush University, Chicago, Illinois
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20
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Wang J, Vaddadi N, Pak JS, Park Y, Quilez S, Roman CA, Dumontier E, Thornton JW, Cloutier JF, Özkan E. Molecular and structural basis of olfactory sensory neuron axon coalescence by Kirrel receptors. Cell Rep 2021; 37:109940. [PMID: 34731636 PMCID: PMC8628261 DOI: 10.1016/j.celrep.2021.109940] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 07/30/2021] [Accepted: 10/13/2021] [Indexed: 01/21/2023] Open
Abstract
Projections from sensory neurons of olfactory systems coalesce into glomeruli in the brain. The Kirrel receptors are believed to homodimerize via their ectodomains and help separate sensory neuron axons into Kirrel2- or Kirrel3-expressing glomeruli. Here, we present the crystal structures of homodimeric Kirrel receptors and show that the closely related Kirrel2 and Kirrel3 have evolved specific sets of polar and hydrophobic interactions, respectively, disallowing heterodimerization while preserving homodimerization, likely resulting in proper segregation and coalescence of Kirrel-expressing axons into glomeruli. We show that the dimerization interface at the N-terminal immunoglobulin (IG) domains is necessary and sufficient to create homodimers and fail to find evidence for a secondary interaction site in Kirrel ectodomains. Furthermore, we show that abolishing dimerization of Kirrel3 in vivo leads to improper formation of glomeruli in the mouse accessory olfactory bulb as observed in Kirrel3-/- animals. Our results provide evidence for Kirrel3 homodimerization controlling axonal coalescence.
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Affiliation(s)
- Jing Wang
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA; Grossman Institute for Neuroscience, Quantitative Biology and Human Behavior, The University of Chicago, Chicago, IL 60637, USA
| | - Neelima Vaddadi
- The Neuro-Montreal Neurological Institute and Hospital, McGill University, Montréal, QC H3A 2B4, Canada; Department of Neurology and Neurosurgery, McGill University, Montréal, QC H3A 2B4, Canada
| | - Joseph S Pak
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA; Grossman Institute for Neuroscience, Quantitative Biology and Human Behavior, The University of Chicago, Chicago, IL 60637, USA
| | - Yeonwoo Park
- Committee on Genetics, Genomics and Systems Biology, The University of Chicago, Chicago, IL 60637, USA
| | - Sabrina Quilez
- The Neuro-Montreal Neurological Institute and Hospital, McGill University, Montréal, QC H3A 2B4, Canada; Department of Neurology and Neurosurgery, McGill University, Montréal, QC H3A 2B4, Canada
| | - Christina A Roman
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA
| | - Emilie Dumontier
- The Neuro-Montreal Neurological Institute and Hospital, McGill University, Montréal, QC H3A 2B4, Canada
| | - Joseph W Thornton
- Committee on Genetics, Genomics and Systems Biology, The University of Chicago, Chicago, IL 60637, USA; Department of Human Genetics, The University of Chicago, Chicago, IL 60637, USA; Department of Ecology and Evolution, The University of Chicago, Chicago, IL 60637, USA
| | - Jean-François Cloutier
- The Neuro-Montreal Neurological Institute and Hospital, McGill University, Montréal, QC H3A 2B4, Canada; Department of Neurology and Neurosurgery, McGill University, Montréal, QC H3A 2B4, Canada; Department of Anatomy and Cell Biology, McGill University, Montréal, QC H3A 0C7, Canada.
| | - Engin Özkan
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA; Grossman Institute for Neuroscience, Quantitative Biology and Human Behavior, The University of Chicago, Chicago, IL 60637, USA.
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21
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Afsar B, Afsar RE, Demiray A, Covic A, Kanbay M. Deciphering nutritional interventions for podocyte structure and function. Pharmacol Res 2021; 172:105852. [PMID: 34450318 DOI: 10.1016/j.phrs.2021.105852] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 08/22/2021] [Accepted: 08/22/2021] [Indexed: 12/11/2022]
Abstract
Despite increasing awareness and therapeutic options chronic kidney disease (CKD) is still and important health problem and glomerular diseases constitute and important percentage of CKD. Proteinuria/albuminuria is not just a marker; but it also plays a direct pathogenic role in renal disease progression of CKD. Glomerular filtration barrier (GFB) which consists of fenestrated endothelial cells, fused basal membrane and interdigitating podocyte foot process and filtration slits between foot process is the major barrier for proteinuria/albuminuria. Many glomerular diseases are characterized by disruption of GFB podocytes, foot process and slit diaphragm. Many proteinuric diseases are non-specifically targeted by therapeutic agents such as steroids and calcineurin inhibitors with systemic side effects. Thus, there is unmet need for more efficient and less toxic therapeutic options to treat glomerular diseases. In recent years, modification of dietary intake, has been gained to treat pathologic processes introducing the concept of 'food as a medicine'. The effect of various nutritional products on podocyte function and structure is also trending, especially in recent years. In the current review, we summarized the effect of nutritional interventions on podocyte function and structure.
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Affiliation(s)
- Baris Afsar
- Division of Nephrology, Department of Nephrology, Suleyman Demirel University School of Medicine, Isparta, Turkey.
| | - Rengin Elsurer Afsar
- Division of Nephrology, Department of Nephrology, Suleyman Demirel University School of Medicine, Isparta, Turkey
| | - Atalay Demiray
- Department of Medicine, Koc University School of Medicine, Istanbul, Turkey
| | - Adrian Covic
- Department of Nephrology, Grigore T. Popa' University of Medicine, Iasi, Romania
| | - Mehmet Kanbay
- Division of Nephrology, Department of Medicine, Koc University School of Medicine, Istanbul, Turkey
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22
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Interplay between extracellular matrix components and cellular and molecular mechanisms in kidney fibrosis. Clin Sci (Lond) 2021; 135:1999-2029. [PMID: 34427291 DOI: 10.1042/cs20201016] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 07/30/2021] [Accepted: 08/02/2021] [Indexed: 12/13/2022]
Abstract
Chronic kidney disease (CKD) is characterized by pathological accumulation of extracellular matrix (ECM) proteins in renal structures. Tubulointerstitial fibrosis is observed in glomerular diseases as well as in the regeneration failure of acute kidney injury (AKI). Therefore, finding antifibrotic therapies comprises an intensive research field in Nephrology. Nowadays, ECM is not only considered as a cellular scaffold, but also exerts important cellular functions. In this review, we describe the cellular and molecular mechanisms involved in kidney fibrosis, paying particular attention to ECM components, profibrotic factors and cell-matrix interactions. In response to kidney damage, activation of glomerular and/or tubular cells may induce aberrant phenotypes characterized by overproduction of proinflammatory and profibrotic factors, and thus contribute to CKD progression. Among ECM components, matricellular proteins can regulate cell-ECM interactions, as well as cellular phenotype changes. Regarding kidney fibrosis, one of the most studied matricellular proteins is cellular communication network-2 (CCN2), also called connective tissue growth factor (CTGF), currently considered as a fibrotic marker and a potential therapeutic target. Integrins connect the ECM proteins to the actin cytoskeleton and several downstream signaling pathways that enable cells to respond to external stimuli in a coordinated manner and maintain optimal tissue stiffness. In kidney fibrosis, there is an increase in ECM deposition, lower ECM degradation and ECM proteins cross-linking, leading to an alteration in the tissue mechanical properties and their responses to injurious stimuli. A better understanding of these complex cellular and molecular events could help us to improve the antifibrotic therapies for CKD.
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23
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Hisaoka T, Komori T, Fujimoto K, Kitamura T, Morikawa Y. Comprehensive expression pattern of kin of irregular chiasm-like 3 in the adult mouse brain. Biochem Biophys Res Commun 2021; 563:66-72. [PMID: 34062388 DOI: 10.1016/j.bbrc.2021.05.063] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 05/18/2021] [Indexed: 11/16/2022]
Abstract
Kin of irregular chiasm-like 3 (Kirrel3), a member of the immunoglobulin superfamily, is expressed in the central nervous system during development and in adulthood. It has been reported that Kirrel3 is involved in the axonal fasciculation in the olfactory bulb, the neuronal migration in the pontine nucleus, and the synapse formation in the hippocampal neurons in mice. Although KIRREL3 mutations have been implicated in autism spectrum disorder and intellectual disability in humans, the comprehensive expression pattern of Kirrel3 in the adult brain is not fully understood. To better visualize Kirrel3 expression pattern and to gain insight into the role of Kirrel3 in the brain, we investigated the expression of Kirrel3 in the adult brain of Kirrel3-heterozygous (Kirrel3+/-) mice, in which Kirrel3-expressing cells could be identified by the expression of β-galactosidase (β-gal) in the nucleus of cells. The strong expression of β-gal was observed in the hippocampus, cerebral cortex, olfactory bulb, amygdala, thalamus, and cerebellum. In the hippocampus, β-gal was detected in the dentate gyrus and in the ventral parts of CA1 and CA3, which are known to be involved in the social recognition memory. Within the cerebral cortex, many cells with β-gal expression were observed in the olfactory area and auditory area. In the striatum, neurons with β-gal expression were mainly observed in the ventral striatum. Expression of β-gal was observed in all layers in the cerebellum and olfactory bulb, except for the olfactory nerve layer. Double-immunofluorescence staining of β-galactosidase with neuronal markers revealed that β-gal expression was exclusively detected in neurons. These results suggest that Kirrel3 may be involved in the maintenance of neuronal networks, such as the maintenance of synaptic connectivity and plasticity in the motor, sensory, and cognitive circuits of adult brain.
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Affiliation(s)
- Tomoko Hisaoka
- Department of Anatomy and Neurobiology, Wakayama Medical University, 811-1 Kimiidera, Wakayama, 641-8509, Japan
| | - Tadasuke Komori
- Department of Anatomy and Neurobiology, Wakayama Medical University, 811-1 Kimiidera, Wakayama, 641-8509, Japan
| | - Kohta Fujimoto
- Department of Developmental Genetics, Institute of Advanced Medicine, Wakayama Medical University, 811-1 Kimiidera, Wakayama, 641-8509, Japan
| | - Toshio Kitamura
- Division of Cellular Therapy, Advanced Clinical Research Center, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo, 108-8639, Japan
| | - Yoshihiro Morikawa
- Department of Anatomy and Neurobiology, Wakayama Medical University, 811-1 Kimiidera, Wakayama, 641-8509, Japan.
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24
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Hildebrand JD, Leventry AD, Aideyman OP, Majewski JC, Haddad JA, Bisi DC, Kaufmann N. A modifier screen identifies regulators of cytoskeletal architecture as mediators of Shroom-dependent changes in tissue morphology. Biol Open 2021; 10:bio.055640. [PMID: 33504488 PMCID: PMC7875558 DOI: 10.1242/bio.055640] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Regulation of cell architecture is critical in the formation of tissues during animal development. The mechanisms that control cell shape must be both dynamic and stable in order to establish and maintain the correct cellular organization. Previous work has identified Shroom family proteins as essential regulators of cell morphology during vertebrate development. Shroom proteins regulate cell architecture by directing the subcellular distribution and activation of Rho-kinase, which results in the localized activation of non-muscle myosin II. Because the Shroom-Rock-myosin II module is conserved in most animal model systems, we have utilized Drosophila melanogaster to further investigate the pathways and components that are required for Shroom to define cell shape and tissue architecture. Using a phenotype-based heterozygous F1 genetic screen for modifiers of Shroom activity, we identified several cytoskeletal and signaling protein that may cooperate with Shroom. We show that two of these proteins, Enabled and Short stop, are required for ShroomA-induced changes in tissue morphology and are apically enriched in response to Shroom expression. While the recruitment of Ena is necessary, it is not sufficient to redefine cell morphology. Additionally, this requirement for Ena appears to be context dependent, as a variant of Shroom that is apically localized, binds to Rock, but lacks the Ena binding site, is still capable of inducing changes in tissue architecture. These data point to important cellular pathways that may regulate contractility or facilitate Shroom-mediated changes in cell and tissue morphology. Summary: Using Drosophila as a model system, we identify F-actin and microtubules as important determinants of how cells and tissues respond to Shroom induced contractility.
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Affiliation(s)
- Jeffrey D Hildebrand
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Adam D Leventry
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Omoregie P Aideyman
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - John C Majewski
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - James A Haddad
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Dawn C Bisi
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Nancy Kaufmann
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
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25
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Gandhi T, Lee CC. Neural Mechanisms Underlying Repetitive Behaviors in Rodent Models of Autism Spectrum Disorders. Front Cell Neurosci 2021; 14:592710. [PMID: 33519379 PMCID: PMC7840495 DOI: 10.3389/fncel.2020.592710] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 12/09/2020] [Indexed: 12/15/2022] Open
Abstract
Autism spectrum disorder (ASD) is comprised of several conditions characterized by alterations in social interaction, communication, and repetitive behaviors. Genetic and environmental factors contribute to the heterogeneous development of ASD behaviors. Several rodent models display ASD-like phenotypes, including repetitive behaviors. In this review article, we discuss the potential neural mechanisms involved in repetitive behaviors in rodent models of ASD and related neuropsychiatric disorders. We review signaling pathways, neural circuits, and anatomical alterations in rodent models that display robust stereotypic behaviors. Understanding the mechanisms and circuit alterations underlying repetitive behaviors in rodent models of ASD will inform translational research and provide useful insight into therapeutic strategies for the treatment of repetitive behaviors in ASD and other neuropsychiatric disorders.
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Affiliation(s)
- Tanya Gandhi
- Department of Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, LA, United States
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26
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Kirrel3-Mediated Synapse Formation Is Attenuated by Disease-Associated Missense Variants. J Neurosci 2020; 40:5376-5388. [PMID: 32503885 DOI: 10.1523/jneurosci.3058-19.2020] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 05/24/2020] [Accepted: 05/26/2020] [Indexed: 12/12/2022] Open
Abstract
Missense variants in Kirrel3 are repeatedly identified as risk factors for autism spectrum disorder and intellectual disability, but it has not been reported if or how these variants disrupt Kirrel3 function. Previously, we studied Kirrel3 loss of function using KO mice and showed that Kirrel3 is a synaptic adhesion molecule necessary to form one specific type of hippocampal synapse in vivo Here, we developed an in vitro, gain-of-function assay for Kirrel3 using neuron cultures prepared from male and female mice and rats. We find that WT Kirrel3 induces synapse formation selectively between Kirrel3-expressing neurons via homophilic, transcellular binding. We tested six disease-associated Kirrel3 missense variants and found that five attenuate this synaptogenic function. All variants tested traffic to the cell surface and localize to synapses similar to WT Kirrel3. Two tested variants lack homophilic transcellular binding, which likely accounts for their reduced synaptogenic function. Interestingly, we also identified variants that bind in trans but cannot induce synapses, indicating that Kirrel3 transcellular binding is necessary but not sufficient for its synaptogenic function. Collectively, these results suggest Kirrel3 functions as a synaptogenic, cell-recognition molecule, and this function is attenuated by missense variants associated with autism spectrum disorder and intellectual disability. Thus, we provide critical insight to the mechanism of Kirrel3 function and the consequences of missense variants associated with autism and intellectual disability.SIGNIFICANCE STATEMENT Here, we advance our understanding of mechanisms mediating target-specific synapse formation by providing evidence that Kirrel3 transcellular interactions mediate target recognition and signaling to promote synapse development. Moreover, this study tests the effects of disease-associated Kirrel3 missense variants on synapse formation, and thereby, increases understanding of the complex etiology of neurodevelopmental disorders arising from rare missense variants in synaptic genes.
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27
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Chen K, Zhao R, Yao G, Liu Z, Shi R, Geng J. Overexpression of kin of IRRE-Like protein 1 (KIRREL) as a prognostic biomarker for breast cancer. Pathol Res Pract 2020; 216:153000. [PMID: 32534710 DOI: 10.1016/j.prp.2020.153000] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 04/08/2020] [Accepted: 05/07/2020] [Indexed: 12/01/2022]
Abstract
OBJECTIVES The purpose of this study was to investigate the expression of Kin of IRRE-Like Protein 1 (KIRREL) and its clinicopathologic significance in breast cancer. MATERIALS AND METHODS The mRNA and protein expressions of KIRREL in fresh breast cancer tissue specimens and the corresponding noncancerous tissue specimens were examined by western blot analysis (n = 24) and RT-qPCR (n = 48). KIRREL was detected by immunohistochemistry (IHC) using breast cancer tissue microarrays (TMAs) in 302 patients. The prognostic roles and clinicopathologic significances in breast cancer were statistically analyzed. RESULTS Compared with para-carcinoma tissues, KIRREL mRNA and protein were overexpressed in breast cancer tissues. Immunohistochemical results showed that the high expression rate of KIRREL staining in breast cancer was 43.7% (132/302). Moreover, Expression of KIRREL was significantly correlated with Her2 status and survival outcomes of patients. Patients with both positive expression of KIRREL showed shorter overall survival (OS) and progression free survival (PFS). Additionally, Cox multivariate survival analysis revealed that KIRREL level, age, primary tumor size, tumor stage and distant metastasis were the independent parameter predicting the prognosis of breast cancer patients. CONCLUSIONS KIRREL was overexpressed in breast cancer and the overexpression of KIRREL could serve as an independent predictor of poor prognosis in breast cancer patients.
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Affiliation(s)
- Kexin Chen
- Department of Pathology, Harbin Medical University Cancer Hospital, No.150, Haping Road, Nangang District, Harbin, Heilongjiang, China
| | - Rui Zhao
- Department of Otolaryngology-Head and Neck Surgery, The Second Affiliated Hospital of Harbin Medical University, No.246, Xuefu Road, Nangang District, Harbin, Heilongjiang, China
| | - Guodong Yao
- Department of Pathology, Harbin Medical University Cancer Hospital, No.150, Haping Road, Nangang District, Harbin, Heilongjiang, China
| | - Zhao Liu
- Department of Ultrasound, Harbin Medical University Cancer Hospital, No.150, Haping Road, Nangang District, Harbin, Heilongjiang, China
| | - Runze Shi
- Department of Breast Surgery, Harbin Medical University Cancer Hospital, No.150, Haping Road, Nangang District, Harbin, Heilongjiang, China
| | - Jingshu Geng
- Department of Pathology, Harbin Medical University Cancer Hospital, No.150, Haping Road, Nangang District, Harbin, Heilongjiang, China.
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Kawachi H, Fukusumi Y. New insight into podocyte slit diaphragm, a therapeutic target of proteinuria. Clin Exp Nephrol 2020; 24:193-204. [PMID: 32020343 PMCID: PMC7040068 DOI: 10.1007/s10157-020-01854-3] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 01/15/2020] [Indexed: 12/26/2022]
Abstract
Dysfunction of slit diaphragm, a cell–cell junction of glomerular podocytes, is involved in the development of proteinuria in several glomerular diseases. Slit diaphragm should be a target of a novel therapy for proteinuria. Nephrin, NEPH1, P-cadherin, FAT, and ephrin-B1 were reported to be extracellular components forming a molecular sieve of the slit diaphragm. Several cytoplasmic proteins such as ZO-1, podocin, CD2AP, MAGI proteins and Par-complex molecules were identified as scaffold proteins linking the slit diaphragm to the cytoskeleton. In this article, new insights into these molecules and the pathogenic roles of the dysfunction of these molecules were introduced. The slit diaphragm functions not only as a barrier but also as a signaling platform transfer the signal to the inside of the cell. For maintaining the slit diaphragm function properly, the phosphorylation level of nephrin is strictly regulated. The recent studies on the signaling pathway from nephrin, NEPH1, and ephrin-B1 were reviewed. Although the mechanism regulating the function of the slit diaphragm had remained unclear, recent studies revealed TRPC6 and angiotensin II-regulating mechanisms play a critical role in regulating the barrier function of the slit diaphragm. In this review, recent investigations on the regulation of the slit diaphragm function were reviewed, and a strategy for the establishment of a novel therapy for proteinuria was proposed.
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Affiliation(s)
- Hiroshi Kawachi
- Department of Cell Biology, Kidney Research Center, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan.
| | - Yoshiyasu Fukusumi
- Department of Cell Biology, Kidney Research Center, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan
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29
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Solanki AK, Widmeier E, Arif E, Sharma S, Daga A, Srivastava P, Kwon SH, Hugo H, Nakayama M, Mann N, Majmundar AJ, Tan W, Gee HY, Sadowski CE, Rinat C, Becker-Cohen R, Bergmann C, Rosen S, Somers M, Shril S, Huber TB, Mane S, Hildebrandt F, Nihalani D. Mutations in KIRREL1, a slit diaphragm component, cause steroid-resistant nephrotic syndrome. Kidney Int 2019; 96:883-889. [PMID: 31472902 PMCID: PMC6756928 DOI: 10.1016/j.kint.2019.06.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 06/11/2019] [Accepted: 06/14/2019] [Indexed: 12/22/2022]
Abstract
Steroid-resistant nephrotic syndrome is a frequent cause of chronic kidney disease almost inevitably progressing to end-stage renal disease. More than 58 monogenic causes of SRNS have been discovered and majority of known steroid-resistant nephrotic syndrome causing genes are predominantly expressed in glomerular podocytes, placing them at the center of disease pathogenesis. Herein, we describe two unrelated families with steroid-resistant nephrotic syndrome with homozygous mutations in the KIRREL1 gene. One mutation showed high frequency in the European population (minor allele frequency 0.0011) and this patient achieved complete remission following treatment, but later progressed to chronic kidney disease. We found that mutant KIRREL1 proteins failed to localize to the podocyte cell membrane, indicating defective trafficking and impaired podocytes function. Thus, the KIRREL1 gene product has an important role in modulating the integrity of the slit diaphragm and maintaining glomerular filtration function.
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Affiliation(s)
- Ashish K Solanki
- Department of Medicine, Nephrology Division, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Eugen Widmeier
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA; Department of Medicine IV, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Ehtesham Arif
- Department of Medicine, Nephrology Division, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Shailza Sharma
- Department of Medicine, Nephrology Division, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Ankana Daga
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Pankaj Srivastava
- Department of Medicine, Nephrology Division, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Sang-Ho Kwon
- Department of Cellular Biology and Anatomy, Augusta University, Augusta, Georgia, USA
| | - Hannah Hugo
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Makiko Nakayama
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Nina Mann
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Amar J Majmundar
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Wei Tan
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Heon Yung Gee
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA; Department of Pharmacology, Brain Korea 21 Program for Leading Universities & Students (PLUS) Project for Medical Sciences, Yonsei University College of Medicine, Seoul, Korea
| | - Caroline E Sadowski
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Choni Rinat
- Division of Pediatric Nephrology, Shaare Zedek Medical Center, The Hadassah-Hebrew University School of Medicine, Jerusalem, Israel
| | - Rachel Becker-Cohen
- Division of Pediatric Nephrology, Shaare Zedek Medical Center, The Hadassah-Hebrew University School of Medicine, Jerusalem, Israel
| | - Carsten Bergmann
- Department of Medicine IV, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Seymour Rosen
- Department of Pathology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Michael Somers
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Shirlee Shril
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Tobias B Huber
- Department of Medicine IV, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany; III Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Biological Signalling Studies (BIOSS) Center for Biological Signaling Studies, Albert-Ludwigs-University, Freiburg, Germany
| | - Shrikant Mane
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Friedhelm Hildebrandt
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
| | - Deepak Nihalani
- Department of Medicine, Nephrology Division, Medical University of South Carolina, Charleston, South Carolina, USA.
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Li J, Wang L, Wan L, Lin T, Zhao W, Cui H, Li H, Cao L, Wu J, Zhang T. Mutational spectrum and novel candidate genes in Chinese children with sporadic steroid-resistant nephrotic syndrome. Pediatr Res 2019; 85:816-821. [PMID: 30712057 DOI: 10.1038/s41390-019-0321-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 10/30/2018] [Accepted: 12/21/2018] [Indexed: 02/04/2023]
Abstract
BACKGROUND Approximately 10-20% of children with idiopathic nephrotic syndrome (NS) fail to respond to steroid therapy. NS is divided into steroid-sensitive NS (SSNS) and steroid-resistant NS (SRNS). Over 45 recessive and dominant genes have been found to be associated with SRNS and/or focal segmental glomerulosclerosis (FSGS). METHODS Targeted sequencing of 339 candidate genes, expressed in glomerular filtration barrier or located in the signaling pathway of podocyte function, were sequenced by NGS in a cohort of total 89 Chinese Han children (29 sporadic SRNS, 33 sporadic SSNS, and 27 healthy). RESULTS Two variants (WT1 p.R441X and NPHS2 p.G149V) were screened out as pathogenic mutations and 14 variants were likely pathogenic. Mutations of KIRREL2 (SRNS vs SSNS: 24.1% vs 3.0%, adjusted OR = 10.11, 95% CI: 1.56-198.66, P = 0.039) were significantly associated with the risk of pediatric sporadic SRNS. Besides, three pathogenic or likely pathogenic variants were identified in HP gene. CONCLUSION Two pathogenic mutations and 14 likely pathogenic mutations were discovered through targeted sequencing of 339 candidate genes. Two genes, HP and KIRREL2, as candidate genes, were first proposed to be associated with the risk of pediatric sporadic SRNS.
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Affiliation(s)
- Jianguo Li
- Department of Rheumatology and Immunology, Children's Hospital Affiliated to Capital Institute of Pediatrics, YaBao Road 2, 100020, Beijing, China.
| | - Lijun Wang
- The Intensive Care Unit 2, Children's Hospital of Hebei Province, 050031, Shijiazhuang, Hebei Province, China
| | - Ling Wan
- Department of Nephrology, Children's Hospital Affiliated to Capital Institute of Pediatrics, YaBao Road 2, 100020, Beijing, China
| | - Tiantian Lin
- Department of Nephrology, Children's Hospital Affiliated to Capital Institute of Pediatrics, YaBao Road 2, 100020, Beijing, China
| | | | - Hang Cui
- Vishuo MedTech Ltd, 100070, Beijing, China
| | - Huarong Li
- Department of Nephrology, Children's Hospital Affiliated to Capital Institute of Pediatrics, YaBao Road 2, 100020, Beijing, China
| | - Li Cao
- Department of Nephrology, Children's Hospital Affiliated to Capital Institute of Pediatrics, YaBao Road 2, 100020, Beijing, China
| | - Jianxin Wu
- Department of Biochemistry, Capital Institute of Pediatrics, YaBao Road 2, 100020, Beijing, China
| | - Ting Zhang
- Molecular Immunology Laboratory, Capital Institute of Pediatrics, YaBao Road 2, 100020, Beijing, China
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Lundgren S, Fagerström-Vahman H, Zhang C, Ben-Dror L, Mardinoglu A, Uhlen M, Nodin B, Jirström K. Discovery of KIRREL as a biomarker for prognostic stratification of patients with thin melanoma. Biomark Res 2019; 7:1. [PMID: 30675360 PMCID: PMC6332842 DOI: 10.1186/s40364-018-0153-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 12/28/2018] [Indexed: 12/20/2022] Open
Abstract
There is a great unmet clinical need to identify patients with thin primary cutaneous melanomas (T1, Breslow thickness ≤ 1 mm) who have a high risk for tumour recurrence and death from melanoma. Kin of IRRE-like protein 1 (KIRREL/NEPH1) is expressed in podocytes and involved in glomerular filtration. Screening in the Human Protein Atlas portal revealed a particularly high expression of KIRREL in melanoma, both at the mRNA and protein levels. In this study, we followed up on these findings and examined the prognostic value of KIRREL in a population-based cohort. Immunohistochemical expression of KIRREL was examined in tissue microarrays with a subset of primary tumours and paired lymph node metastases from an original cohort of 268 incident cases of melanoma in the Malmö Diet and Cancer study. KIRREL mRNA expression was examined in 103 melanoma cases in The Cancer Genome Atlas (TCGA). Membranous/cytoplasmic expression of KIRREL was detected in 158/185 (85.4%) primary tumours and 18/19 (94.7%) metastases. High expression of KIRREL was significantly associated with several unfavourable clinicopathological factors. High KIRREL protein expression was an independent factor of reduced recurrence free and melanoma specific survival, particularly in thin melanomas, even outperforming absolute thickness and ulceration (HR = 30.85; 95% CI 1.54-616.36 and HR = 6.32 95% CI 1.19-33.65). High mRNA levels of KIRREL were not significantly associated with survival in TCGA. In conclusion, KIRREL is not only a novel potential diagnostic marker for melanoma, but may also be a useful prognostic biomarker for improved stratification of patients with thin melanoma. These findings may be of high clinical relevance and therefore merit further validation.
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Affiliation(s)
- Sebastian Lundgren
- 1Department of Clinical Sciences Lund, Oncology and Pathology, Lund University, Lund, Sweden
| | | | - Cheng Zhang
- 2Science for Life Laboratory, Department of Proteomics, School of Biotechnology, Royal Institute of Technology, Stockholm, Sweden
| | - Liv Ben-Dror
- 1Department of Clinical Sciences Lund, Oncology and Pathology, Lund University, Lund, Sweden
| | - Adil Mardinoglu
- 2Science for Life Laboratory, Department of Proteomics, School of Biotechnology, Royal Institute of Technology, Stockholm, Sweden
| | - Mathias Uhlen
- 2Science for Life Laboratory, Department of Proteomics, School of Biotechnology, Royal Institute of Technology, Stockholm, Sweden
| | - Björn Nodin
- 1Department of Clinical Sciences Lund, Oncology and Pathology, Lund University, Lund, Sweden
| | - Karin Jirström
- 1Department of Clinical Sciences Lund, Oncology and Pathology, Lund University, Lund, Sweden
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Zhang MJ, Hong YY, Li N. Overexpression of Kin of IRRE-Like Protein 1 (KIRREL) in Gastric Cancer and Its Clinical Prognostic Significance. Med Sci Monit 2018; 24:2711-2719. [PMID: 29717104 PMCID: PMC5952805 DOI: 10.12659/msm.910386] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Background The aim of this study was to examine the expression level of IRRE-like protein 1 (KIRREL) in gastric cancer (GC) and to explore its prognostic significance. Material/Methods Bioinformatics methods were used to predict the differential expression levels of KIRREL mRNA in GC and normal gastric tissues by mining cancer-related databases (TCGA and Oncomine). Immunohistochemistry was done to verify the KIRREL protein expression levels in 71 cases of GC tissues combined with matched normal tissues. The relationship between clinicopathologic parameters and KIRREL differential expression levels in GC was investigated by the chi-square test. Kaplan-Meier univariate and Cox multivariate survival analyses were performed to explore the prognostic significance of KIRREL expression in GC patients. Results TCGA and GEO data analyses showed that KIRREL mRNA expression level was remarkably higher in GC than that in normal gastric tissues (both P<0.05). KIRREL mRNA levels were dramatically increased from stage I to stage IV (P=0.037). Immunohistochemical results showed that the high positive rate of KIRREL staining in GC was 61.97% (44/71). Moreover, GC patients with KIRREL mRNA or protein high levels had significantly shorter overall survival times than those with KIRREL mRNA or low protein levels (All P<0.05). Additionally, Cox multivariate survival analysis revealed that KIRREL differential expression levels (low vs. high) were the only independent parameter predicting the prognosis of GC patients (P=0.000). Conclusions KIRREL was overexpressed in GC and the overexpression of KIRREL could serve as an independent predictor of poor prognosis in GC patients.
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Affiliation(s)
- Ming-Jun Zhang
- Department of Oncology, The Second Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China (mainland)
| | - Yan-Yan Hong
- Department of Oncology, The Second Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China (mainland)
| | - Na Li
- Department of Oncology, The Second Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China (mainland)
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Muraleedharan S, Sam A, Skaer H, Inamdar MS. Networks that link cytoskeletal regulators and diaphragm proteins underpin filtration function in Drosophila nephrocytes. Exp Cell Res 2018; 364:234-242. [PMID: 29458174 PMCID: PMC5883325 DOI: 10.1016/j.yexcr.2018.02.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 02/06/2018] [Accepted: 02/15/2018] [Indexed: 11/25/2022]
Abstract
Insect nephrocytes provide a valuable model for kidney disease, as they are structurally and functionally homologous to mammalian kidney podocytes. They possess an exceptional macromolecular assembly, the nephrocyte diaphragm (ND), which serves as a filtration barrier and helps maintain tissue homeostasis by filtering out wastes and toxic products. However, the elements that maintain nephrocyte architecture and the ND are not understood. We show that Drosophila nephrocytes have a unique cytoplasmic cluster of F-actin, which is maintained by the microtubule cytoskeleton and Rho-GTPases. A balance of Rac1 and Cdc42 activity as well as proper microtubule organization and endoplasmic reticulum structure, are required to position the actin cluster. Further, ND proteins Sns and Duf also localize to this cluster and regulate organization of the actin and microtubule cytoskeleton. Perturbation of any of these inter-dependent components impairs nephrocyte ultrafiltration. Thus cytoskeletal components, Rho-GTPases and ND proteins work in concert to maintain the specialized nephrocyte architecture and function. Drosophila nephrocytes have a unique cytoplasmic cluster of F-actin. Microtubules, Rho-GTPases and endoplasmic reticulum position the actin cluster. Nephrocyte diaphragm proteins localize to and regulate actin cluster organization. Perturbation of any of these inter-dependent components impairs ultrafiltration.
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Affiliation(s)
- Simi Muraleedharan
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India
| | - Aksah Sam
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India
| | - Helen Skaer
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
| | - Maneesha S Inamdar
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India; Institute for Stem Cell Biology and Regenerative Medicine, GKVK, Bellary Road, Bangalore 560065, India.
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Abstract
Ultimately, the common final pathway of any glomerular disease is podocyte effacement, podocyte loss, and, eventually, glomerular scarring. There has been a long-standing debate on the underlying mechanisms for podocyte depletion, ranging from necrosis and apoptosis to detachment of viable cells from the glomerular basement membrane. However, this debate still continues because additional pathways of programmed cell death have been reported in recent years. Interestingly, viable podocytes can be isolated out of the urine of proteinuric patients easily, emphasizing the importance of podocyte detachment in glomerular diseases. In contrast, detection of apoptosis and other pathways of programmed cell death in podocytes is technically challenging. In fact, we still are lacking direct evidence showing, for example, the presence of apoptotic bodies in podocytes, leaving the question unanswered as to whether podocytes undergo mechanisms of programmed cell death. However, understanding the mechanisms leading to podocyte depletion is of particular interest because future therapeutic strategies might interfere with these to prevent glomerular scarring. In this review, we summarize our current knowledge on podocyte cell death, the different molecular pathways and experimental approaches to study these, and, finally, focus on the mechanisms that prevent the onset of programmed cell death.
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Affiliation(s)
- Fabian Braun
- Department II of Internal Medicine, Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Ageing-Associated Diseases, University of Cologne, Cologne, Germany
| | - Jan U Becker
- Institute of Pathology, University Hospital of Cologne, Cologne, Germany
| | - Paul T Brinkkoetter
- Department II of Internal Medicine, Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Ageing-Associated Diseases, University of Cologne, Cologne, Germany.
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Martin CE, Jones N. Nephrin Signaling in the Podocyte: An Updated View of Signal Regulation at the Slit Diaphragm and Beyond. Front Endocrinol (Lausanne) 2018; 9:302. [PMID: 29922234 PMCID: PMC5996060 DOI: 10.3389/fendo.2018.00302] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 05/22/2018] [Indexed: 12/11/2022] Open
Abstract
Podocytes are a major component of the glomerular blood filtration barrier, and alterations to the morphology of their unique actin-based foot processes (FP) are a common feature of kidney disease. Adjacent FP are connected by a specialized intercellular junction known as the slit diaphragm (SD), which serves as the ultimate barrier to regulate passage of macromolecules from the blood. While the link between SD dysfunction and reduced filtration selectivity has been recognized for nearly 50 years, our understanding of the underlying molecular circuitry began only 20 years ago, sparked by the identification of NPHS1, encoding the transmembrane protein nephrin. Nephrin not only functions as the core component of the extracellular SD filtration network but also as a signaling scaffold via interactions at its short intracellular region. Phospho-regulation of several conserved tyrosine residues in this region influences signal transduction pathways which control podocyte cell adhesion, shape, and survival, and emerging studies highlight roles for nephrin phospho-dynamics in mechanotransduction and endocytosis. The following review aims to summarize the last 5 years of advancement in our knowledge of how signaling centered at nephrin directs SD barrier formation and function. We further provide insight on promising frontiers in podocyte biology, which have implications for SD signaling in the healthy and diseased kidney.
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Wang Q. CpG methylation patterns are associated with gene expression variation in osteosarcoma. Mol Med Rep 2017; 16:901-907. [DOI: 10.3892/mmr.2017.6635] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Accepted: 01/27/2017] [Indexed: 11/05/2022] Open
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A functional variant in NEPH3 gene confers high risk of renal failure in primary hematuric glomerulopathies. Evidence for predisposition to microalbuminuria in the general population. PLoS One 2017; 12:e0174274. [PMID: 28334007 PMCID: PMC5363870 DOI: 10.1371/journal.pone.0174274] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Accepted: 03/06/2017] [Indexed: 01/06/2023] Open
Abstract
Background Recent data emphasize that thin basement membrane nephropathy (TBMN) should not be viewed as a form of benign familial hematuria since chronic renal failure (CRF) and even end-stage renal disease (ESRD), is a possible development for a subset of patients on long-term follow-up, through the onset of focal and segmental glomerulosclerosis (FSGS). We hypothesize that genetic modifiers may explain this variability of symptoms. Methods We looked in silico for potentially deleterious functional SNPs, using very strict criteria, in all the genes significantly expressed in the slit diaphragm (SD). Two variants were genotyped in a cohort of well-studied adult TBMN patients from 19 Greek-Cypriot families, with a homogeneous genetic background. Patients were categorized as “Severe” or “Mild”, based on the presence or not of proteinuria, CRF and ESRD. A larger pooled cohort (HEMATURIA) of 524 patients, including IgA nephropathy patients, was used for verification. Additionally, three large general population cohorts [Framingham Heart Study (FHS), KORAF4 and SAPHIR] were used to investigate if the NEPH3-V353M variant has any renal effect in the general population. Results and conclusions Genotyping for two high-scored variants in 103 TBMN adult patients with founder mutations who were classified as mildly or severely affected, pointed to an association with variant NEPH3-V353M (filtrin). This promising result prompted testing in the larger pooled cohort (HEMATURIA), indicating an association of the 353M variant with disease severity under the dominant model (p = 3.0x10-3, OR = 6.64 adjusting for gender/age; allelic association: p = 4.2x10-3 adjusting for patients’ kinships). Subsequently, genotyping 6,531 subjects of the Framingham Heart Study (FHS) revealed an association of the homozygous 353M/M genotype with microalbuminuria (p = 1.0x10-3). Two further general population cohorts, KORAF4 and SAPHIR confirmed the association, and a meta-analysis of all three cohorts (11,258 individuals) was highly significant (p = 1.3x10-5, OR = 7.46). Functional studies showed that Neph3 homodimerization and Neph3-Nephrin heterodimerization are disturbed by variant 353M. Additionally, 353M was associated with differential activation of the unfolded protein response pathway, when overexpressed in stressed cultured undifferentiated podocyte cells, thus attesting to its functional significance. Genetics and functional studies support a “rare variant-strong effect” role for NEPH3-V353M, by exerting a negative modifier effect on primary glomerular hematuria. Additionally, genetics studies provide evidence for a role in predisposing homozygous subjects of the general population to micro-albuminuria.
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Roh JD, Choi SY, Cho YS, Choi TY, Park JS, Cutforth T, Chung W, Park H, Lee D, Kim MH, Lee Y, Mo S, Rhee JS, Kim H, Ko J, Choi SY, Bae YC, Shen K, Kim E, Han K. Increased Excitatory Synaptic Transmission of Dentate Granule Neurons in Mice Lacking PSD-95-Interacting Adhesion Molecule Neph2/Kirrel3 during the Early Postnatal Period. Front Mol Neurosci 2017; 10:81. [PMID: 28381988 PMCID: PMC5360738 DOI: 10.3389/fnmol.2017.00081] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Accepted: 03/08/2017] [Indexed: 11/13/2022] Open
Abstract
Copy number variants and point mutations of NEPH2 (also called KIRREL3) gene encoding an immunoglobulin (Ig) superfamily adhesion molecule have been linked to autism spectrum disorders, intellectual disability and neurocognitive delay associated with Jacobsen syndrome, but the physiological roles of Neph2 in the mammalian brain remain largely unknown. Neph2 is highly expressed in the dentate granule (DG) neurons of the hippocampus and is localized in both dendrites and axons. It was recently shown that Neph2 is required for the formation of mossy fiber filopodia, the axon terminal structure of DG neurons forming synapses with GABAergic neurons of CA3. In contrast, however, it is unknown whether Neph2 also has any roles in the postsynaptic compartments of DG neurons. We here report that, through its C-terminal PDZ domain-binding motif, Neph2 directly interacts with postsynaptic density (PSD)-95, an abundant excitatory postsynaptic scaffolding protein. Moreover, Neph2 protein is detected in the brain PSD fraction and interacts with PSD-95 in synaptosomal lysates. Functionally, loss of Neph2 in mice leads to age-specific defects in the synaptic connectivity of DG neurons. Specifically, Neph2-/- mice show significantly increased spontaneous excitatory synaptic events in DG neurons at postnatal week 2 when the endogenous Neph2 protein expression peaks, but show normal excitatory synaptic transmission at postnatal week 3. The evoked excitatory synaptic transmission and synaptic plasticity of medial perforant pathway (MPP)-DG synapses are also normal in Neph2-/- mice at postnatal week 3, further confirming the age-specific synaptic defects. Together, our results provide some evidence for the postsynaptic function of Neph2 in DG neurons during the early postnatal period, which might be implicated in neurodevelopmental and cognitive disorders caused by NEPH2 mutations.
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Affiliation(s)
- Junyeop D Roh
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST) Daejeon, South Korea
| | - Su-Yeon Choi
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS) Daejeon, South Korea
| | - Yi Sul Cho
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University Daegu, South Korea
| | - Tae-Yong Choi
- Department of Physiology, Dental Research Institute, Seoul National University School of Dentistry Seoul, South Korea
| | - Jong-Sil Park
- Department of Physiology, Dental Research Institute, Seoul National University School of Dentistry Seoul, South Korea
| | - Tyler Cutforth
- Department of Neurology, Columbia University Medical Center New York, NY, USA
| | - Woosuk Chung
- Department of Anesthesiology and Pain Medicine, College of Medicine, Chungnam National University Daejeon, South Korea
| | - Hanwool Park
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS) Daejeon, South Korea
| | - Dongsoo Lee
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS) Daejeon, South Korea
| | - Myeong-Heui Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST) Daejeon, South Korea
| | - Yeunkum Lee
- Department of Neuroscience, College of Medicine, Korea University Seoul, South Korea
| | - Seojung Mo
- Department of Anatomy, College of Medicine, Korea University Seoul, South Korea
| | - Jeong-Seop Rhee
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine Göttingen, Germany
| | - Hyun Kim
- Department of Anatomy, College of Medicine, Korea University Seoul, South Korea
| | - Jaewon Ko
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST) Daegu, South Korea
| | - Se-Young Choi
- Department of Physiology, Dental Research Institute, Seoul National University School of Dentistry Seoul, South Korea
| | - Yong Chul Bae
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University Daegu, South Korea
| | - Kang Shen
- Department of Biology, Howard Hughes Medical Institute, Stanford University Stanford, CA, USA
| | - Eunjoon Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST)Daejeon, South Korea; Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS)Daejeon, South Korea
| | - Kihoon Han
- Department of Neuroscience, College of Medicine, Korea University Seoul, South Korea
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Swiatecka-Urban A. Endocytic Trafficking at the Mature Podocyte Slit Diaphragm. Front Pediatr 2017; 5:32. [PMID: 28286744 PMCID: PMC5324021 DOI: 10.3389/fped.2017.00032] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 02/03/2017] [Indexed: 12/16/2022] Open
Abstract
Endocytic trafficking couples cell signaling with the cytoskeletal dynamics by organizing a crosstalk between protein networks in different subcellular compartments. Proteins residing in the plasma membrane are internalized and transported as cargo in endocytic vesicles (i.e., endocytosis). Subsequently, cargo proteins can be delivered to lysosomes for degradation or recycled back to the plasma membrane. The slit diaphragm is a modified tight junction connecting foot processes of the glomerular epithelial cells, podocytes. Signaling at the slit diaphragm plays a critical role in the kidney while its dysfunction leads to glomerular protein loss (proteinuria), manifesting as nephrotic syndrome, a rare condition with an estimated incidence of 2-4 new cases per 100,000 each year. Relatively little is known about the role of endocytic trafficking in podocyte signaling and maintenance of the slit diaphragm integrity. This review will focus on the role of endocytic trafficking at the mature podocyte slit diaphragm.
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Affiliation(s)
- Agnieszka Swiatecka-Urban
- Department of Nephrology, Children's Hospital of Pittsburgh, Pittsburgh, PA, USA; Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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Angiotensin II increases glomerular permeability by β-arrestin mediated nephrin endocytosis. Sci Rep 2016; 6:39513. [PMID: 28004760 PMCID: PMC5177899 DOI: 10.1038/srep39513] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 11/21/2016] [Indexed: 01/13/2023] Open
Abstract
Glomerular permeability and subsequent albuminuria are early clinical markers for glomerular injury in hypertensive nephropathy. Albuminuria predicts mortality and cardiovascular morbidity. AT1 receptor blockers protect from albuminuria, cardiovascular morbidity and mortality. A blood pressure independent, molecular mechanism for angiotensin II (Ang II) dependent albuminuria has long been postulated. Albuminuria results from a defective glomerular filter. Nephrin is a major structural component of the glomerular slit diaphragm and its endocytosis is mediated by β-arrestin2. Ang II stimulation increases nephrin-β-arrestin2 binding, nephrin endocytosis and glomerular permeability in mice. This Ang II effect is mediated by AT1-receptors. AT1-receptor mutants identified G-protein signaling to be essential for this Ang II effect. Gαq knockdown and phospholipase C inhibition block Ang II mediated enhanced nephrin endocytosis. Nephrin Y1217 is the critical residue controlling nephrin binding to β-arrestin under Ang II stimulation. Nephrin Y1217 also mediates cytoskeletal anchoring to actin via nck2. Ang II stimulation decreases nephrin nck2 binding. We conclude that Ang II weakens the structural integrity of the slit diaphragm by increased nephrin endocytosis and decreased nephrin binding to nck2, which leads to increased glomerular permeability. This novel molecular mechanism of Ang II supports the use of AT1-receptor blockers to prevent albuminuria even in normotensives.
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Abstract
Genetic studies of hereditary forms of nephrotic syndrome have identified several proteins that are involved in regulating the permselective properties of the glomerular filtration system. Further extensive research has elucidated the complex molecular basis of the glomerular filtration barrier and clearly established the pivotal role of podocytes in the pathophysiology of glomerular diseases. Podocyte architecture is centred on focal adhesions and slit diaphragms - multiprotein signalling hubs that regulate cell morphology and function. A highly interconnected actin cytoskeleton enables podocytes to adapt in order to accommodate environmental changes and maintain an intact glomerular filtration barrier. Actin-based endocytosis has now emerged as a regulator of podocyte integrity, providing an impetus for understanding the precise mechanisms that underlie the steady-state control of focal adhesion and slit diaphragm components. This Review outlines the role of actin dynamics and endocytosis in podocyte biology, and discusses how molecular heterogeneity in glomerular disorders could be exploited to deliver more rational therapeutic interventions, paving the way for targeted medicine in nephrology.
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42
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Grahammer F, Wigge C, Schell C, Kretz O, Patrakka J, Schneider S, Klose M, Kind J, Arnold SJ, Habermann A, Bräuniger R, Rinschen MM, Völker L, Bregenzer A, Rubbenstroth D, Boerries M, Kerjaschki D, Miner JH, Walz G, Benzing T, Fornoni A, Frangakis AS, Huber TB. A flexible, multilayered protein scaffold maintains the slit in between glomerular podocytes. JCI Insight 2016; 1:86177. [PMID: 27430022 DOI: 10.1172/jci.insight.86177] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Vertebrate life critically depends on renal filtration and excretion of low molecular weight waste products. This process is controlled by a specialized cell-cell contact between podocyte foot processes: the slit diaphragm (SD). Using a comprehensive set of targeted KO mice of key SD molecules, we provided genetic, functional, and high-resolution ultrastructural data highlighting a concept of a flexible, dynamic, and multilayered architecture of the SD. Our data indicate that the mammalian SD is composed of NEPHRIN and NEPH1 molecules, while NEPH2 and NEPH3 do not participate in podocyte intercellular junction formation. Unexpectedly, homo- and heteromeric NEPHRIN/NEPH1 complexes are rarely observed. Instead, single NEPH1 molecules appear to form the lower part of the junction close to the glomerular basement membrane with a width of 23 nm, while single NEPHRIN molecules form an adjacent junction more apically with a width of 45 nm. In both cases, the molecules are quasiperiodically spaced 7 nm apart. These structural findings, in combination with the flexibility inherent to the repetitive Ig folds of NEPHRIN and NEPH1, indicate that the SD likely represents a highly dynamic cell-cell contact that forms an adjustable, nonclogging barrier within the renal filtration apparatus.
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Affiliation(s)
- Florian Grahammer
- Department of Medicine, Division of Nephrology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Christoph Wigge
- Buchmann Institute for Molecular Life Sciences and Institute for Biophysics, Goethe University Frankfurt, Frankfurt, Germany
| | - Christoph Schell
- Department of Medicine, Division of Nephrology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Spemann Graduate School of Biology and Medicine.,Faculty of Biology, and
| | - Oliver Kretz
- Department of Medicine, Division of Nephrology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,BIOSS Center for Biological Signalling Studies, Albert-Ludwigs University of Freiburg, Freiburg, Germany.,Institute of Anatomy, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Jaakko Patrakka
- KI/AZ Integrated Cardio-Metabolic Center (ICMC), Department of Laboratory Medicine, Karolinska Institutet at Karolinska University Hospital Huddinge, Stockholm, Sweden
| | - Simon Schneider
- Department of Medicine, Division of Nephrology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Martin Klose
- Institute of Molecular Medicine and Cell Research, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,German Cancer Consortium and.,German Cancer Research Center, Heidelberg, Germany
| | - Julia Kind
- Department of Medicine, Division of Nephrology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Sebastian J Arnold
- Department of Medicine, Division of Nephrology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,BIOSS Center for Biological Signalling Studies, Albert-Ludwigs University of Freiburg, Freiburg, Germany.,Institute of Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Anja Habermann
- Buchmann Institute for Molecular Life Sciences and Institute for Biophysics, Goethe University Frankfurt, Frankfurt, Germany
| | - Ricarda Bräuniger
- Buchmann Institute for Molecular Life Sciences and Institute for Biophysics, Goethe University Frankfurt, Frankfurt, Germany
| | - Markus M Rinschen
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Linus Völker
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Andreas Bregenzer
- Department of Medicine, Division of Nephrology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Dennis Rubbenstroth
- Institute of Virology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Germany
| | - Melanie Boerries
- Institute of Molecular Medicine and Cell Research, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,German Cancer Consortium and.,German Cancer Research Center, Heidelberg, Germany
| | | | - Jeffrey H Miner
- Renal Division, Washington University, St. Louis, Missouri, USA
| | - Gerd Walz
- Department of Medicine, Division of Nephrology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Thomas Benzing
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Alessia Fornoni
- Division of Nephrology and Katz Family Drug Discovery Center, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Achilleas S Frangakis
- Buchmann Institute for Molecular Life Sciences and Institute for Biophysics, Goethe University Frankfurt, Frankfurt, Germany
| | - Tobias B Huber
- Department of Medicine, Division of Nephrology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Spemann Graduate School of Biology and Medicine.,BIOSS Center for Biological Signalling Studies, Albert-Ludwigs University of Freiburg, Freiburg, Germany.,FRIAS, Freiburg Institute for Advanced Studies and ZBSA, Center for Biological System Analysis, Albert-Ludwigs-University of Freiburg, Germany
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43
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Ren Q, You Yu S. CD2-associated protein participates in podocyte apoptosis via PI3K/Akt signaling pathway. J Recept Signal Transduct Res 2015; 36:288-91. [PMID: 26584949 DOI: 10.3109/10799893.2015.1101137] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
CD2-associated protein is one of the most important slit diaphragm proteins in maintaining podocyte integrity and reducing proteinuria. In the last 15 years, progressive researches have shown that CD2AP serves as an adaptor protein, plays essential roles in the podocyte cytoskeletal structure and signaling from the extracellular SD to the intracellular dynamic actin cytoskeleton. CD2AP deficient or transcript abnormality would lead to podocyte failure and proteinuric glomerular diseases. In this study, we demonstrate that CD2AP and p85 regulatory subunit of phosphoinositide 3-OH kinase (PI3K), recruit PI3K to the plasma membrane, and stimulate PI3K-dependent AKT signaling in podocytes the CD2AP-mediated AKT activity can regulate complex biological programs. PAN reduces Akt phosphorylation levels of GSK3β, LY294002 can promote podocyte apoptosis induced by PAN. Our findings suggest that the activation of PI3K/AKT signaling represents an essential component to maintain the functional integrity of podocytes. And PI3K/Akt signaling pathway play an important role in podocyte apoptosis.
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Affiliation(s)
- Qi Ren
- a Department of Pediatrics , Allergy, Immunology and Rheumatology, Guangzhou Medical University , Guangdong , China and
| | - Sheng You Yu
- b Guangzhou Medical University, Guangzhou People's Hospital , Guangdong , China
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44
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Villarreal R, Mitrofanova A, Maiguel D, Morales X, Jeon J, Grahammer F, Leibiger IB, Guzman J, Fachado A, Yoo TH, Busher Katin A, Gellermann J, Merscher S, Burke GW, Berggren PO, Oh J, Huber TB, Fornoni A. Nephrin Contributes to Insulin Secretion and Affects Mammalian Target of Rapamycin Signaling Independently of Insulin Receptor. J Am Soc Nephrol 2015; 27:1029-41. [PMID: 26400569 DOI: 10.1681/asn.2015020210] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 06/19/2015] [Indexed: 12/31/2022] Open
Abstract
Nephrin belongs to a family of highly conserved proteins with a well characterized function as modulators of cell adhesion and guidance, and nephrin may have a role in metabolic pathways linked to podocyte and pancreatic β-cell survival. However, this role is incompletely characterized. In this study, we developed floxed nephrin mice for pancreatic β-cell-specific deletion of nephrin, which had no effect on islet size and glycemia. Nephrin deficiency, however, resulted in glucose intolerance in vivo and impaired glucose-stimulated insulin release ex vivo Glucose intolerance was also observed in eight patients with nephrin mutations compared with three patients with other genetic forms of nephrotic syndrome or nine healthy controls.In vitro experiments were conducted to investigate if nephrin affects autocrine signaling through insulin receptor A (IRA) and B (IRB), which are both expressed in human podocytes and pancreatic islets. Coimmunoprecipitation of nephrin and IRB but not IRA was observed and required IR phosphorylation. Nephrin per se was sufficient to induce phosphorylation of p70S6K in an phosphatidylinositol 3-kinase-dependent but IR/Src-independent manner, which was not augmented by exogenous insulin. These results suggest a role for nephrin as an independent modulator of podocyte and pancreatic β-cell nutrient sensing in the fasting state and the potential of nephrin as a drug target in diabetes.
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Affiliation(s)
- Rodrigo Villarreal
- Katz Family Drug Discovery Center, Division of Nephrology and Hypertension and Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, Florida
| | - Alla Mitrofanova
- Katz Family Drug Discovery Center, Division of Nephrology and Hypertension and
| | - Dony Maiguel
- Katz Family Drug Discovery Center, Division of Nephrology and Hypertension and Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, Florida
| | - Ximena Morales
- Katz Family Drug Discovery Center, Division of Nephrology and Hypertension and
| | - Jongmin Jeon
- Katz Family Drug Discovery Center, Division of Nephrology and Hypertension and Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, Florida
| | | | - Ingo B Leibiger
- Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden
| | - Johanna Guzman
- Katz Family Drug Discovery Center, Division of Nephrology and Hypertension and Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, Florida
| | - Alberto Fachado
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, Florida
| | - Tae H Yoo
- Katz Family Drug Discovery Center, Division of Nephrology and Hypertension and Department of Internal Medicine, Division of Nephrology, Yonsei University College of Medicine, Seoul, Korea
| | - Anja Busher Katin
- Pediatric Nephrology, Pediatrics II, University Children's Hospital Essen, Essen, Germany
| | - Jutta Gellermann
- Department of Pediatric Nephrology, Charité Children's Hospital, Berlin, Germany
| | - Sandra Merscher
- Katz Family Drug Discovery Center, Division of Nephrology and Hypertension and Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, Florida
| | - George W Burke
- Department of Surgery, University of Miami, Miami, Florida; and
| | - Per-Olof Berggren
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, Florida; Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden
| | - Jun Oh
- Pediatric Nephrology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Tobias B Huber
- Renal Division, University Hospital Freiburg, Freiburg, Germany
| | - Alessia Fornoni
- Katz Family Drug Discovery Center, Division of Nephrology and Hypertension and Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, Florida;
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45
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Yesildag B, Bock T, Herrmanns K, Wollscheid B, Stoffel M. Kin of IRRE-like Protein 2 Is a Phosphorylated Glycoprotein That Regulates Basal Insulin Secretion. J Biol Chem 2015; 290:25891-906. [PMID: 26324709 DOI: 10.1074/jbc.m115.684704] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Indexed: 12/17/2022] Open
Abstract
Direct interactions among pancreatic β-cells via cell surface proteins inhibit basal and enhance stimulated insulin secretion. Here, we functionally and biochemically characterized Kirrel2, an immunoglobulin superfamily protein with β-cell-specific expression in the pancreas. Our results show that Kirrel2 is a phosphorylated glycoprotein that co-localizes and interacts with the adherens junction proteins E-cadherin and β-catenin in MIN6 cells. We further demonstrate that the phosphosites Tyr(595-596) are functionally relevant for the regulation of Kirrel2 stability and localization. Analysis of the extracellular and intracellular domains of Kirrel2 revealed that it is cleaved and shed from MIN6 cells and that the remaining membrane spanning cytoplasmic domain is processed by γ-secretase complex. Kirrel2 knockdown with RNA interference in MIN6 cells and ablation of Kirrel2 from mice with genetic deletion resulted in increased basal insulin secretion from β-cells, with no immediate influence on stimulated insulin secretion, total insulin content, or whole body glucose metabolism. Our results show that in pancreatic β-cells Kirrel2 localizes to adherens junctions, is regulated by multiple post-translational events, including glycosylation, extracellular cleavage, and phosphorylation, and engages in the regulation of basal insulin secretion.
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Affiliation(s)
- Burcak Yesildag
- From the Department of Biology, Institute of Molecular Health Sciences, Swiss Federal Institute of Technology (ETH) Zurich, Otto-Stern-Weg 7, 8093 Zurich
| | - Thomas Bock
- the Department of Health Sciences and Technology, Institute of Molecular Systems Biology, Swiss Federal Institute of Technology Zurich, Auguste-Piccard-Hof 1, 8093 Zurich, and
| | - Karolin Herrmanns
- From the Department of Biology, Institute of Molecular Health Sciences, Swiss Federal Institute of Technology (ETH) Zurich, Otto-Stern-Weg 7, 8093 Zurich
| | - Bernd Wollscheid
- the Department of Health Sciences and Technology, Institute of Molecular Systems Biology, Swiss Federal Institute of Technology Zurich, Auguste-Piccard-Hof 1, 8093 Zurich, and
| | - Markus Stoffel
- From the Department of Biology, Institute of Molecular Health Sciences, Swiss Federal Institute of Technology (ETH) Zurich, Otto-Stern-Weg 7, 8093 Zurich, the Department of Health Sciences and Technology, Institute of Molecular Systems Biology, Swiss Federal Institute of Technology Zurich, Auguste-Piccard-Hof 1, 8093 Zurich, and the Faculty of Medicine, University of Zurich, 8091 Zurich, Switzerland
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46
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Choi SY, Han K, Cutforth T, Chung W, Park H, Lee D, Kim R, Kim MH, Choi Y, Shen K, Kim E. Mice lacking the synaptic adhesion molecule Neph2/Kirrel3 display moderate hyperactivity and defective novel object preference. Front Cell Neurosci 2015; 9:283. [PMID: 26283919 PMCID: PMC4517382 DOI: 10.3389/fncel.2015.00283] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 07/10/2015] [Indexed: 11/13/2022] Open
Abstract
Synaptic adhesion molecules regulate diverse aspects of neuronal synapse development, including synapse specificity, formation, and maturation. Neph2, also known as Kirrel3, is an immunoglobulin superfamily adhesion molecule implicated in intellectual disability, neurocognitive delay associated with Jacobsen syndrome, and autism spectrum disorders. We here report mice lacking Neph2 (Neph2(-/-) mice) display moderate hyperactivity in a familiar, but not novel, environment and defective novel object recognition with normal performances in Morris water maze spatial learning and memory, contextual fear conditioning and extinction, and pattern separation tests. These mice also show normal levels of anxiety-like behaviors, social interaction, and repetitive behaviors. At the synapse level, Neph2(-/-) dentate gyrus granule cells exhibit unaltered dendritic spine density and spontaneous excitatory synaptic transmission. These results suggest that Neph2 is important for normal locomotor activity and object recognition memory.
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Affiliation(s)
- Su-Yeon Choi
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology Daejeon, South Korea
| | - Kihoon Han
- Department of Neuroscience and Division of Brain Korea 21, Biomedical Science, College of Medicine, Korea University Seoul, South Korea
| | - Tyler Cutforth
- Department of Neurology, Columbia University Medical Center New York, NY, USA
| | - Woosuk Chung
- Department of Biomedical Sciences, Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology Daejeon, South Korea
| | - Haram Park
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology Daejeon, South Korea
| | - Dongsoo Lee
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science Daejeon, South Korea
| | - Ryunhee Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology Daejeon, South Korea
| | - Myeong-Heui Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology Daejeon, South Korea
| | - Yeeun Choi
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology Daejeon, South Korea
| | - Kang Shen
- Department of Biology, Stanford University Stanford, CA, USA ; Howard Hughes Medical Institute Chevy Chase, MD, USA
| | - Eunjoon Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology Daejeon, South Korea ; Center for Synaptic Brain Dysfunctions, Institute for Basic Science Daejeon, South Korea
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47
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Schell C, Kretz O, Bregenzer A, Rogg M, Helmstädter M, Lisewski U, Gotthardt M, Tharaux PL, Huber TB, Grahammer F. Podocyte-Specific Deletion of Murine CXADR Does Not Impair Podocyte Development, Function or Stress Response. PLoS One 2015; 10:e0129424. [PMID: 26076477 PMCID: PMC4468136 DOI: 10.1371/journal.pone.0129424] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 05/10/2015] [Indexed: 12/27/2022] Open
Abstract
The coxsackie- and adenovirus receptor (CXADR) is a member of the immunoglobulin protein superfamily, present in various epithelial cells including glomerular epithelial cells. Beside its known function as a virus receptor, it also constitutes an integral part of cell-junctions. Previous studies in the zebrafish pronephros postulated a potential role of CXADR for the terminal differentiation of glomerular podocytes and correct patterning of the elaborated foot process architecture. However, due to early embryonic lethality of constitutive Cxadr knockout mice, mammalian data on kidney epithelial cells have been lacking. Interestingly, Cxadr is robustly expressed during podocyte development and in adulthood in response to glomerular injury. We therefore used a conditional transgenic approach to elucidate the function of Cxadr for podocyte development and stress response. Surprisingly, we could not discern a developmental phenotype in podocyte specific Cxadr knock-out mice. In addition, despite a significant up regulation of CXADR during toxic, genetic and immunologic podocyte injury, we could not detect any impact of Cxadr on these injury models. Thus these data indicate that in contrast to lower vertebrate models, mammalian podocytes have acquired molecular programs to compensate for the loss of Cxadr.
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Affiliation(s)
- Christoph Schell
- Renal Division, University Medical Center Freiburg, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine (SGBM), Albert-Ludwigs University Freiburg, Freiburg, Germany
- Faculty of Biology, Albert-Ludwigs University Freiburg, Freiburg, Germany
| | - Oliver Kretz
- Renal Division, University Medical Center Freiburg, Freiburg, Germany
- Department of Neuroanatomy, Albert-Ludwigs University Freiburg, Freiburg, Germany
| | - Andreas Bregenzer
- Renal Division, University Medical Center Freiburg, Freiburg, Germany
| | - Manuel Rogg
- Renal Division, University Medical Center Freiburg, Freiburg, Germany
| | | | - Ulrike Lisewski
- Max-Delbrueck Center for Molecular Medicine, Berlin, Germany
| | | | | | - Tobias B. Huber
- Renal Division, University Medical Center Freiburg, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine (SGBM), Albert-Ludwigs University Freiburg, Freiburg, Germany
- BIOSS Center for Biological Signaling Studies, Albert-Ludwigs-University Freiburg, Freiburg, Germany
- * E-mail:
| | - Florian Grahammer
- Renal Division, University Medical Center Freiburg, Freiburg, Germany
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48
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Linneweber GA, Winking M, Fischbach KF. The Cell Adhesion Molecules Roughest, Hibris, Kin of Irre and Sticks and Stones Are Required for Long Range Spacing of the Drosophila Wing Disc Sensory Sensilla. PLoS One 2015; 10:e0128490. [PMID: 26053791 PMCID: PMC4459997 DOI: 10.1371/journal.pone.0128490] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 04/27/2015] [Indexed: 12/18/2022] Open
Abstract
Most animal tissues and organ systems are comprised of highly ordered arrays of varying cell types. The development of external sensory organs requires complex cell-cell communication in order to give each cell a specific identity and to ensure a regular distributed pattern of the sensory bristles. This involves both long and short range signaling mediated by either diffusible or cell anchored factors. In a variety of processes the heterophilic Irre Cell Recognition Module, consisting of the Neph-like proteins: Roughest, Kin of irre and of the Nephrin-like proteins: Sticks and Stones, Hibris, plays key roles in the recognition events of different cell types throughout development. In the present study these proteins are apically expressed in the adhesive belt of epithelial cells participating in sense organ development in a partially exclusive and asymmetric manner. Using mutant analysis the GAL4/UAS system, RNAi and gain of function we found an involvement of all four Irre Cell Recognition Module-proteins in the development of a highly structured array of sensory organs in the wing disc. The proteins secure the regular spacing of sensory organs showing partial redundancy and may function in early lateral inhibition events as well as in cell sorting processes. Comparisons with other systems suggest that the Irre Cell Recognition module is a key organizer of highly repetitive structures.
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Affiliation(s)
- Gerit Arne Linneweber
- Department of Neurobiology, Albert-Ludwigs-University Freiburg, Schänzlestr. 1, D-79104, Freiburg, Germany
| | - Mathis Winking
- Department of Neurobiology, Albert-Ludwigs-University Freiburg, Schänzlestr. 1, D-79104, Freiburg, Germany
| | - Karl-Friedrich Fischbach
- Department of Neurobiology, Albert-Ludwigs-University Freiburg, Schänzlestr. 1, D-79104, Freiburg, Germany
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49
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An update: the role of Nephrin inside and outside the kidney. SCIENCE CHINA-LIFE SCIENCES 2015; 58:649-57. [PMID: 25921941 DOI: 10.1007/s11427-015-4844-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 02/27/2015] [Indexed: 12/18/2022]
Abstract
Nephrin is a key molecule in podocytes to maintain normal slit diaphragm structure. Nephin interacts with many other podocyte and slit diaphragm protein and also mediates important cell signaling pathways in podocytes. Loss of nephrin during the development leads to the congenital nephrotic syndrome in children. Reduction of nephrin expression is often observed in adult kidney diseases including diabetic nephropathy and HIV-associated nephropathy. The critical role of nephrin has been confirmed by different animal models with nephrin knockout and knockdown. Recent studies demonstrate that knockdown of nephrin expression in adult mice aggravates the progression of unilateral nephrectomy and Adriamycin-induced kidney disease. In addition to its critical role in maintaining normal glomerular filtration unit in the kidney, nephrin is also expressed in other organs. However, the exact role of nephrin in kidney and extra-renal organs has not been well characterized. Future studies are required to determine whether nephrin could be developed as a drug target to treat patients with kidney disease.
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50
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Dong L, Pietsch S, Tan Z, Perner B, Sierig R, Kruspe D, Groth M, Witzgall R, Gröne HJ, Platzer M, Englert C. Integration of Cistromic and Transcriptomic Analyses Identifies Nphs2, Mafb, and Magi2 as Wilms' Tumor 1 Target Genes in Podocyte Differentiation and Maintenance. J Am Soc Nephrol 2015; 26:2118-28. [PMID: 25556170 DOI: 10.1681/asn.2014080819] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Accepted: 10/10/2014] [Indexed: 11/03/2022] Open
Abstract
The Wilms' tumor suppressor gene 1 (WT1) encodes a zinc finger transcription factor. Mutation of WT1 in humans leads to Wilms' tumor, a pediatric kidney tumor, or other kidney diseases, such as Denys-Drash and Frasier syndromes. We showed previously that inactivation of WT1 in podocytes of adult mice results in proteinuria, foot process effacement, and glomerulosclerosis. However, the WT1-dependent transcriptional network regulating podocyte development and maintenance in vivo remains unknown. Here, we performed chromatin immunoprecipitation followed by high-throughput sequencing with glomeruli from wild-type mice. Additionally, we performed a cDNA microarray screen on an inducible podocyte-specific WT1 knockout mouse model. By integration of cistromic and transcriptomic analyses, we identified the WT1 targetome in mature podocytes. To further analyze the function and targets of WT1 in podocyte maturation, we used an Nphs2-Cre model, in which WT1 is deleted during podocyte differentiation. These mice display anuria and kidney hemorrhage and die within 24 hours after birth. To address the evolutionary conservation of WT1 targets, we performed functional assays using zebrafish as a model and identified Nphs2, Mafb, and Magi2 as novel WT1 target genes required for podocyte development. Our data also show that both Mafb and Magi2 are required for normal development of the embryonic zebrafish kidney. Collectively, our work provides insights into the transcriptional networks controlled by WT1 and identifies novel WT1 target genes that mediate the function of WT1 in podocyte differentiation and maintenance.
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Affiliation(s)
| | | | | | | | | | | | - Marco Groth
- Genome Analysis, Leibniz Institute for Age Research, Fritz Lipmann Institute, Jena, Germany
| | - Ralph Witzgall
- Institute for Molecular and Cellular Anatomy, University of Regensburg, Regensburg, Germany
| | - Hermann-Josef Gröne
- Department of Cellular and Molecular Pathology, German Cancer Research Center, Heidelberg, Germany; and
| | - Matthias Platzer
- Genome Analysis, Leibniz Institute for Age Research, Fritz Lipmann Institute, Jena, Germany
| | - Christoph Englert
- Departments of Molecular Genetics and Faculty of Biology and Pharmacy, Friedrich Schiller University of Jena, Jena, Germany
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