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Xu J, Hu H, Sun Y, Zhao Z, Zhang D, Yang L, Lu Q. The fate of immune complexes in membranous nephropathy. Front Immunol 2024; 15:1441017. [PMID: 39185424 PMCID: PMC11342396 DOI: 10.3389/fimmu.2024.1441017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2024] [Accepted: 07/24/2024] [Indexed: 08/27/2024] Open
Abstract
The most characteristic feature of membranous nephropathy (MN) is the presence of subepithelial electron dense deposits and the consequential thickening of the glomerular basement membrane. There have been great advances in the understanding of the destiny of immune complexes in MN by the benefit of experimental models represented by Heymann nephritis. Subepithelial immune complexes are formed in situ by autoantibodies targeting native autoantigens or exogenous planted antigens such as the phospholipase A2 receptor (PLA2R) and cationic BSA respectively. The nascent immune complexes would not be pathogenic until they develop into immune deposits. Podocytes are the major source of autoantigens in idiopathic membranous nephropathy. They also participate in the modulation and removal of the immune complexes to a large extent. The balance between deposition and clearance is regulated by a wide range of factors such as the composition and physicochemical properties of the immune complexes and the complement system. Complement components such as C3 and C1q have been reported to be precipitated with the deposits whereas a complement regulatory protein CR1 expressed by podocytes is involved in the phagocytosis of immune complexes by podocytes. Podocytes regulate the dynamic change of immune complexes which is disturbed in membranous nephropathy. To elucidate the precise fate of the immune complexes is essential for developing more rational and novel therapies for membranous nephropathy.
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Affiliation(s)
- Jie Xu
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Haikun Hu
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Yuhe Sun
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Zihan Zhao
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Danyuan Zhang
- Qi Huang of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Lei Yang
- Department of Nephropathy, The Third Affiliated Hospital of Beijing University of Chinese Medicine, Beijing, China
| | - Qingyi Lu
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China
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Liu J, Malhotra D, Ge Y, Gunning W, Dworkin L, Gong R. THSD7A-associated membranous nephropathy involves both complement-mediated and autonomous podocyte injury. Front Pharmacol 2024; 15:1430451. [PMID: 39086386 PMCID: PMC11288966 DOI: 10.3389/fphar.2024.1430451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2024] [Accepted: 06/24/2024] [Indexed: 08/02/2024] Open
Abstract
Membranous nephropathy (MN) continues to be a leading cause of nephrotic syndrome in non-diabetic adults. As a unique subtype in the serology-based classification of MN, thrombospondin type 1 domain containing 7A (THSD7A)-associated MN has attracted increasing interest, because, unlike other autoantigens, THSD7A is also expressed in preclinical species, facilitating the study of its role in MN. A heterologous mouse model of THSD7A-associated MN was previously established using a proprietary in-house antibody that was unfortunately not available to the research community. Here, we developed a mouse model of THSD7A-associated MN by administering a commercially available antibody targeting the most N-terminal part of THSD7A. Our model was characterized by heavy proteinuria and pathological features of human MN without sex differences. Complement depletion with cobra venom factor only partially attenuated proteinuria and glomerular injury in this model, entailing that complement-independent pathomechanisms also contribute. Consistently, in vitro in primary podocytes, exposure to the anti-THSD7A antibody caused evident podocytopathic changes, including disruption of actin cytoskeleton integrity, podocyte hypermobility, oxidative stress, and apoptotic cell death. These signs of podocytopathy were preserved, albeit to a lesser extent, after complement inactivation, indicating autonomous podocyte injury. Furthermore, as the first FDA-approved treatment for primary MN, adrenocorticotropic hormone therapy with repository corticotropin injection (Purified Cortrophin Gel®) appeared to be beneficial and significantly attenuated proteinuria and glomerular injury, suggesting that this model may be useful for developing novel treatments or understanding the pathogenesis of MN. Collectively, our model, based on the use of a commercially available anti-THSD7A antibody, will be an important tool for MN research.
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Affiliation(s)
- Jing Liu
- Division of Nephrology, Department of Medicine, Toledo, OH, United States
| | - Deepak Malhotra
- Division of Nephrology, Department of Medicine, Toledo, OH, United States
| | - Yan Ge
- Division of Nephrology, Department of Medicine, Toledo, OH, United States
| | - William Gunning
- Department of Pathology, The University of Toledo College of Medicine, Toledo, OH, United States
| | - Lance Dworkin
- Division of Nephrology, Department of Medicine, Toledo, OH, United States
| | - Rujun Gong
- Division of Nephrology, Department of Medicine, Toledo, OH, United States
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Tanaka K, Hayasaka H, Matsusaka T. Dach1 is essential for maintaining normal mature podocytes. PLoS One 2024; 19:e0303910. [PMID: 38805434 PMCID: PMC11132487 DOI: 10.1371/journal.pone.0303910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 05/03/2024] [Indexed: 05/30/2024] Open
Abstract
Dach1 is highly expressed in normal podocytes, but this expression rapidly disappears after podocyte injury. To investigate the role of Dach1 in podocytes in vivo, we analyzed global, podocyte-specific, and inducible Dach1 knockout mice. Global Dach1 knockout (Dach1-/-) mice were assessed immediately after birth because they die within a day. The kidneys of Dach1-/- mice were slightly smaller than those of control mice but maintained a normal structure and normal podocyte phenotypes, including ultrastructure. To study the role of Dach1 in mature podocytes, we generated Dach1 knockout mice by mating Dach1fl/fl mice with Nphs1-Cre or ROSA-CreERT2 mice. Due to inefficient Cre recombination, only a small number of podocytes lacked Dach1 staining in these mice. However, all eleven Nphs1-Cre/Dach1fl/fl mice displayed abnormal albuminuria, and seven (63%) of them developed focal segmental glomerulosclerosis. Among 13 ROSA-CreERT2/Dach1fl/fl mice, eight (61%) exhibited abnormal albuminuria after treatment with tamoxifen, and five (38%) developed early sclerotic lesions. These results indicate that while Dach1 does not determine the fate of differentiation into podocytes, it is indispensable for maintaining the normal integrity of mature podocytes.
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Affiliation(s)
- Keiko Tanaka
- Departments of Physiology, Tokai University School of Medicine, Kanagawa, Japan
- Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Haruko Hayasaka
- Department of Science, Faculty of Science & Engineering, Graduate School of Science and Engineering, Kindai University, Osaka, Japan
| | - Taiji Matsusaka
- Departments of Physiology, Tokai University School of Medicine, Kanagawa, Japan
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Bărar AA, Pralea IE, Maslyennikov Y, Munteanu R, Berindan-Neagoe I, Pîrlog R, Rusu I, Nuțu A, Rusu CC, Moldovan DT, Potra AR, Tirinescu D, Ticala M, Elec FI, Iuga CA, Kacso IM. Minimal Change Disease: Pathogenetic Insights from Glomerular Proteomics. Int J Mol Sci 2024; 25:5613. [PMID: 38891801 PMCID: PMC11171934 DOI: 10.3390/ijms25115613] [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: 03/15/2024] [Revised: 05/13/2024] [Accepted: 05/15/2024] [Indexed: 06/21/2024] Open
Abstract
The mechanism underlying podocyte dysfunction in minimal change disease (MCD) remains unknown. This study aimed to shed light on the potential pathophysiology of MCD using glomerular proteomic analysis. Shotgun proteomics using label-free quantitative mass spectrometry was performed on formalin-fixed, paraffin-embedded (FFPE) renal biopsies from two groups of samples: control (CTR) and MCD. Glomeruli were excised from FFPE renal biopsies using laser capture microdissection (LCM), and a single-pot solid-phase-enhanced sample preparation (SP3) digestion method was used to improve yield and protein identifications. Principal component analysis (PCA) revealed a distinct separation between the CTR and MCD groups. Forty-eight proteins with different abundance between the two groups (p-value ≤ 0.05 and |FC| ≥ 1.5) were identified. These may represent differences in podocyte structure, as well as changes in endothelial or mesangial cells and extracellular matrix, and some were indeed found in several of these structures. However, most differentially expressed proteins were linked to the podocyte cytoskeleton and its dynamics. Some of these proteins are known to be involved in focal adhesion (NID1 and ITGA3) or slit diaphragm signaling (ANXA2, TJP1 and MYO1C), while others are structural components of the actin and microtubule cytoskeleton of podocytes (ACTR3 and NES). This study suggests the potential of mass spectrometry-based shotgun proteomic analysis with LCM glomeruli to yield valuable insights into the pathogenesis of podocytopathies like MCD. The most significantly dysregulated proteins in MCD could be attributable to cytoskeleton dysfunction or may be a compensatory response to cytoskeleton malfunction caused by various triggers.
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Affiliation(s)
- Andrada Alina Bărar
- Department of Nephrology, Faculty of Medicine, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania; (A.A.B.); (Y.M.); (C.C.R.); (D.T.M.); (A.R.P.); (D.T.); (M.T.); (I.M.K.)
| | - Ioana-Ecaterina Pralea
- Department of Proteomics and Metabolomics, Research Center for Advanced Medicine–MedFuture, “Iuliu Hațieganu” University of Medicine and Pharmacy Cluj-Napoca, Louis Pasteur Street 4-6, 400349 Cluj-Napoca, Romania;
| | - Yuriy Maslyennikov
- Department of Nephrology, Faculty of Medicine, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania; (A.A.B.); (Y.M.); (C.C.R.); (D.T.M.); (A.R.P.); (D.T.); (M.T.); (I.M.K.)
| | - Raluca Munteanu
- Department of In Vivo Studies, Research Center for Advanced Medicine–MedFuture, “Iuliu Hațieganu” University of Medicine and Pharmacy Cluj-Napoca, Louis Pasteur Street 6, 400349 Cluj-Napoca, Romania;
| | - Ioana Berindan-Neagoe
- Research Center for Functional Genomics, Biomedicine and Translational Medicine, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400337 Cluj-Napoca, Romania; (I.B.-N.); (R.P.); (A.N.)
| | - Radu Pîrlog
- Research Center for Functional Genomics, Biomedicine and Translational Medicine, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400337 Cluj-Napoca, Romania; (I.B.-N.); (R.P.); (A.N.)
| | - Ioana Rusu
- Department of Pathology, Regional Institute of Gastroenterology and Hepatology, 400394 Cluj-Napoca, Romania;
| | - Andreea Nuțu
- Research Center for Functional Genomics, Biomedicine and Translational Medicine, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400337 Cluj-Napoca, Romania; (I.B.-N.); (R.P.); (A.N.)
| | - Crina Claudia Rusu
- Department of Nephrology, Faculty of Medicine, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania; (A.A.B.); (Y.M.); (C.C.R.); (D.T.M.); (A.R.P.); (D.T.); (M.T.); (I.M.K.)
| | - Diana Tania Moldovan
- Department of Nephrology, Faculty of Medicine, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania; (A.A.B.); (Y.M.); (C.C.R.); (D.T.M.); (A.R.P.); (D.T.); (M.T.); (I.M.K.)
| | - Alina Ramona Potra
- Department of Nephrology, Faculty of Medicine, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania; (A.A.B.); (Y.M.); (C.C.R.); (D.T.M.); (A.R.P.); (D.T.); (M.T.); (I.M.K.)
| | - Dacian Tirinescu
- Department of Nephrology, Faculty of Medicine, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania; (A.A.B.); (Y.M.); (C.C.R.); (D.T.M.); (A.R.P.); (D.T.); (M.T.); (I.M.K.)
| | - Maria Ticala
- Department of Nephrology, Faculty of Medicine, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania; (A.A.B.); (Y.M.); (C.C.R.); (D.T.M.); (A.R.P.); (D.T.); (M.T.); (I.M.K.)
| | - Florin Ioan Elec
- Department of Urology, Faculty of Medicine, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania;
| | - Cristina Adela Iuga
- Department of Proteomics and Metabolomics, Research Center for Advanced Medicine–MedFuture, “Iuliu Hațieganu” University of Medicine and Pharmacy Cluj-Napoca, Louis Pasteur Street 4-6, 400349 Cluj-Napoca, Romania;
- Department of Pharmaceutical Analysis, Faculty of Pharmacy, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400349 Cluj-Napoca, Romania
| | - Ina Maria Kacso
- Department of Nephrology, Faculty of Medicine, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania; (A.A.B.); (Y.M.); (C.C.R.); (D.T.M.); (A.R.P.); (D.T.); (M.T.); (I.M.K.)
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Buerger F, Salmanullah D, Liang L, Gauntner V, Krueger K, Qi M, Sharma V, Rubin A, Ball D, Lemberg K, Saida K, Merz LM, Sever S, Issac B, Sun L, Guerrero-Castillo S, Gomez AC, McNulty MT, Sampson MG, Al-Hamed MH, Saleh MM, Shalaby M, Kari J, Fawcett JP, Hildebrandt F, Majmundar AJ. Recessive variants in the intergenic NOS1AP-C1orf226 locus cause monogenic kidney disease responsive to anti-proteinuric treatment. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.03.17.24303374. [PMID: 38562757 PMCID: PMC10984069 DOI: 10.1101/2024.03.17.24303374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
In genetic disease, an accurate expression landscape of disease genes and faithful animal models will enable precise genetic diagnoses and therapeutic discoveries, respectively. We previously discovered that variants in NOS1AP , encoding nitric oxide synthase 1 (NOS1) adaptor protein, cause monogenic nephrotic syndrome (NS). Here, we determined that an intergenic splice product of N OS1AP / Nos1ap and neighboring C1orf226/Gm7694 , which precludes NOS1 binding, is the predominant isoform in mammalian kidney transcriptional and proteomic data. Gm7694 -/- mice, whose allele exclusively disrupts the intergenic product, developed NS phenotypes. In two human NS subjects, we identified causative NOS1AP splice variants, including one predicted to abrogate intergenic splicing but initially misclassified as benign based on the canonical transcript. Finally, by modifying genetic background, we generated a faithful mouse model of NOS1AP -associated NS, which responded to anti-proteinuric treatment. This study highlights the importance of intergenic splicing and a potential treatment avenue in a mendelian disorder.
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Waller AP, Wolfgang KJ, Pruner I, Stevenson ZS, Abdelghani E, Muralidharan K, Wilkie TK, Blissett AR, Calomeni EP, Vetter TA, Brodsky SV, Smoyer WE, Nieman MT, Kerlin BA. Prothrombin Knockdown Protects Podocytes and Reduces Proteinuria in Glomerular Disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.06.20.544360. [PMID: 38464017 PMCID: PMC10925217 DOI: 10.1101/2023.06.20.544360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Chronic kidney disease (CKD) is a leading cause of death, and its progression is driven by glomerular podocyte injury and loss, manifesting as proteinuria. Proteinuria includes urinary loss of coagulation zymogens, cofactors, and inhibitors. Importantly, both CKD and proteinuria significantly increase the risk of thromboembolic disease. Prior studies demonstrated that anticoagulants reduced proteinuria in rats and that thrombin injured cultured podocytes. Herein we aimed to directly determine the influence of circulating prothrombin on glomerular pathobiology. We hypothesized that (pro)thrombin drives podocytopathy, podocytopenia, and proteinuria. Glomerular proteinuria was induced with puromycin aminonucleoside (PAN) in Wistar rats. Circulating prothrombin was either knocked down using a rat-specific antisense oligonucleotide or elevated by serial intravenous infusions of prothrombin protein, which are previously established methods to model hypo- (LoPT) and hyper-prothrombinemia (HiPT), respectively. After 10 days (peak proteinuria in this model) plasma prothrombin levels were determined, kidneys were examined for (pro)thrombin co-localization to podocytes, histology, and electron microscopy. Podocytopathy and podocytopenia were determined and proteinuria, and plasma albumin were measured. LoPT significantly reduced prothrombin colocalization to podocytes, podocytopathy, and proteinuria with improved plasma albumin. In contrast, HiPT significantly increased podocytopathy and proteinuria. Podocytopenia was significantly reduced in LoPT vs. HiPT rats. In summary, prothrombin knockdown ameliorated PAN-induced glomerular disease whereas hyper-prothrombinemia exacerbated disease. Thus, (pro)thrombin antagonism may be a viable strategy to simultaneously provide thromboprophylaxis and prevent podocytopathy-mediated CKD progression.
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Dourado MN, Pierry PM, Feitosa-Junior OR, Uceda-Campos G, Barbosa D, Zaini PA, Dandekar AM, da Silva AM, Araújo WL. Transcriptome and Secretome Analyses of Endophyte Methylobacterium mesophilicum and Pathogen Xylella fastidiosa Interacting Show Nutrient Competition. Microorganisms 2023; 11:2755. [PMID: 38004766 PMCID: PMC10673610 DOI: 10.3390/microorganisms11112755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 10/25/2023] [Accepted: 11/08/2023] [Indexed: 11/26/2023] Open
Abstract
Xylella fastidiosa is the causal agent of several plant diseases affecting fruit and nut crops. Methylobacterium mesophilicum strain SR1.6/6 was isolated from Citrus sinensis and shown to promote plant growth by producing phytohormones, providing nutrients, inhibiting X. fastidiosa, and preventing Citrus Variegated Chlorosis. However, the molecular mechanisms involved in the interaction among these microbes are still unclear. The present work aimed to analyze physiological and molecular aspects of M. mesophilicum SR1.6/6 and X. fastidiosa 9a5c in co-culture. The transcriptome and secretome analyses indicated that X. fastidiosa down-regulates cell division and transport genes and up-regulates stress via induction of chaperones and pathogenicity-related genes including, the lipase-esterase LesA, a protease, as well as an oligopeptidase in response to M. mesophilicum competition. On the other hand, M. mesophilicum also down-regulated transport genes, except for iron uptake, which was up-regulated. Secretome analysis identified four proteins in M. mesophilicum exclusively produced in co-culture with X. fastidiosa, among these, three are related to phosphorous uptake. These results suggest that M. mesophilicum inhibits X. fastidiosa growth mainly due to nutrient competition for iron and phosphorous, thus promoting X. fastidiosa starvation, besides producing enzymes that degrade X. fastidiosa cell wall, mainly hydrolases. The understanding of these interactions provides a direction for control and management of the phytopathogen X. fastidiosa, and consequently, helps to improve citrus growth and productivity.
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Affiliation(s)
- Manuella Nobrega Dourado
- Microbiology Department, Biomedical Sciences Institute, University of Sao Paulo, Sao Paulo 05508-000, Brazil
- Agronomic Engineering College, University of Sorocaba, Sorocaba, Sao Paulo 18023-000, Brazil
| | - Paulo Marques Pierry
- Biochemistry Department, Chemistry Institute, University of Sao Paulo, Sao Paulo 05508-000, Brazil; (P.M.P.); (O.R.F.-J.)
| | | | - Guillermo Uceda-Campos
- Biochemistry Department, Chemistry Institute, University of Sao Paulo, Sao Paulo 05508-000, Brazil; (P.M.P.); (O.R.F.-J.)
| | - Deibs Barbosa
- Biochemistry Department, Chemistry Institute, University of Sao Paulo, Sao Paulo 05508-000, Brazil; (P.M.P.); (O.R.F.-J.)
| | - Paulo A. Zaini
- Department of Plant Sciences, College of Agricultural and Environmental Sciences, University of California, Davis, CA 95616, USA; (P.A.Z.)
| | - Abhaya M. Dandekar
- Department of Plant Sciences, College of Agricultural and Environmental Sciences, University of California, Davis, CA 95616, USA; (P.A.Z.)
| | - Aline Maria da Silva
- Biochemistry Department, Chemistry Institute, University of Sao Paulo, Sao Paulo 05508-000, Brazil; (P.M.P.); (O.R.F.-J.)
| | - Welington Luiz Araújo
- Microbiology Department, Biomedical Sciences Institute, University of Sao Paulo, Sao Paulo 05508-000, Brazil
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Riedmann H, Kayser S, Helmstädter M, Epting D, Bergmann C. Kif21a deficiency leads to impaired glomerular filtration barrier function. Sci Rep 2023; 13:19161. [PMID: 37932480 PMCID: PMC10628293 DOI: 10.1038/s41598-023-46270-1] [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: 07/26/2023] [Accepted: 10/30/2023] [Indexed: 11/08/2023] Open
Abstract
The renal glomerulus represents the major filtration body of the vertebrate nephron and is responsible for urine production and a number of other functions such as metabolic waste elimination and the regulation of water, electrolyte and acid-base balance. Podocytes are highly specialized epithelial cells that form a crucial part of the glomerular filtration barrier (GFB) by establishing a slit diaphragm for semipermeable plasma ultrafiltration. Defects of the GFB lead to proteinuria and impaired kidney function often resulting in end-stage renal failure. Although significant knowledge has been acquired in recent years, many aspects in podocyte biology are still incompletely understood. By using zebrafish as a vertebrate in vivo model, we report a novel role of the Kinesin-like motor protein Kif21a in glomerular filtration. Our studies demonstrate specific Kif21a localization to the podocytes. Its deficiency resulted in altered podocyte morphology leading to podocyte foot process effacement and altered slit diaphragm formation. Finally, we proved considerable functional consequences of Kif21a deficiency by demonstrating a leaky GFB resulting in severe proteinuria. Conclusively, our data identified a novel role of Kif21a for proper GFB function and adds another piece to the understanding of podocyte architecture and regulation.
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Affiliation(s)
- Hanna Riedmann
- Department of Medicine IV, Faculty of Medicine, Medical Center-University of Freiburg, Breisacher Str.113, 79106, Freiburg, Germany
| | - Séverine Kayser
- Department of Medicine IV, Faculty of Medicine, Medical Center-University of Freiburg, Breisacher Str.113, 79106, Freiburg, Germany
| | - Martin Helmstädter
- Department of Medicine IV, Faculty of Medicine, Medical Center-University of Freiburg, Breisacher Str.113, 79106, Freiburg, Germany
| | - Daniel Epting
- Department of Medicine IV, Faculty of Medicine, Medical Center-University of Freiburg, Breisacher Str.113, 79106, Freiburg, Germany.
| | - Carsten Bergmann
- Department of Medicine IV, Faculty of Medicine, Medical Center-University of Freiburg, Breisacher Str.113, 79106, Freiburg, Germany.
- Limbach Genetics, Medizinische Genetik Mainz, Haifa-Allee 38, 55128, Mainz, Germany.
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Ester L, Cabrita I, Ventzke M, Kieckhöfer E, Christodoulou M, Mandel AM, Diefenhardt P, Fabretti F, Benzing T, Habbig S, Schermer B. The role of the FSGS disease gene product and nuclear pore protein NUP205 in regulating nuclear localization and activity of transcriptional regulators YAP and TAZ. Hum Mol Genet 2023; 32:3153-3165. [PMID: 37565816 PMCID: PMC10630254 DOI: 10.1093/hmg/ddad135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 07/31/2023] [Accepted: 08/10/2023] [Indexed: 08/12/2023] Open
Abstract
Mutations in genes encoding nuclear pore proteins (NUPs) lead to the development of steroid-resistant nephrotic syndrome and focal segmental glomerulosclerosis (FSGS). However, the precise molecular mechanisms by which NUP dysfunction contributes to podocyte injury preceding FSGS remain unclear. The tightly regulated activity of Yes-associated protein (YAP) and WW-domain-containing transcription regulator 1 (TAZ), the transcriptional effectors of the Hippo pathway, is crucial for podocytes and the maintenance of the glomerular filter. In this study, we investigate the impact of NUPs on the regulation of YAP/TAZ nuclear import and activity in podocytes. In unbiased interactome studies using quantitative label-free mass spectrometry, we identify the FSGS disease gene products NUP107, NUP133, NUP205, and Exportin-5 (XPO5) as components of YAP and TAZ protein complexes in podocytes. Moreover, we demonstrate that NUP205 is essential for YAP/TAZ nuclear import. Consistently, both the nuclear interaction of YAP/TAZ with TEA domain transcription factor 1 and their transcriptional activity were dependent on NUP205 expression. Additionally, we elucidate a regulatory feedback mechanism whereby YAP activity is modulated in response to TAZ-mediated NUP205 expression. In conclusion, this study establishes a connection between the FSGS disease protein NUP205 and the activity of the transcriptional regulators and Hippo effectors YAP and TAZ and it proposes a potential pathological role of YAP/TAZ dysregulation in podocytes of patients with pathogenic NUP205 variants.
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Affiliation(s)
- Lioba Ester
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Faculty of Medicine and University Hospital Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany
| | - Inês Cabrita
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Faculty of Medicine and University Hospital Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany
| | - Michel Ventzke
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Faculty of Medicine and University Hospital Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany
| | - Emilia Kieckhöfer
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Faculty of Medicine and University Hospital Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany
| | - Marita Christodoulou
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Faculty of Medicine and University Hospital Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany
| | - Amrei M Mandel
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Faculty of Medicine and University Hospital Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany
| | - Paul Diefenhardt
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Faculty of Medicine and University Hospital Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany
| | - Francesca Fabretti
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Faculty of Medicine and University Hospital Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany
| | - Thomas Benzing
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Faculty of Medicine and University Hospital Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany
| | - Sandra Habbig
- Department of Pediatrics, University of Cologne, Faculty of Medicine and University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany
| | - Bernhard Schermer
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Faculty of Medicine and University Hospital Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany
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10
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Hackl A, Nüsken E, Voggel J, Abo Zed SED, Binz-Lotter J, Unnersjö-Jess D, Müller C, Fink G, Bohl K, Wiesner E, Diefenhardt P, Dafinger C, Chen H, Wohlfarth M, Müller RU, Hackl MJ, Schermer B, Nüsken KD, Weber LT. The effect of mycophenolate mofetil on podocytes in nephrotoxic serum nephritis. Sci Rep 2023; 13:14167. [PMID: 37644089 PMCID: PMC10465485 DOI: 10.1038/s41598-023-41222-1] [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: 04/28/2023] [Accepted: 08/23/2023] [Indexed: 08/31/2023] Open
Abstract
Mycophenolate mofetil (MMF) is applied in proteinuric kidney diseases, but the exact mechanism of its effect on podocytes is still unknown. Our previous in vitro experiments suggested that MMF can ameliorate podocyte damage via restoration of the Ca2+-actin cytoskeleton axis. The goal of this study was to characterize podocyte biology during MMF treatment in nephrotoxic serum (NTS) nephritis (NTN). NTN was induced in three-week old wild-type mice. On day 3, half of the mice were treated with MMF (100 mg/kgBW/d p.o.) for one week. On day 10, we performed proteomic analysis of glomeruli as well as super-resolution imaging of the slit diaphragm. For multiphoton imaging of Ca2+ concentration ([Ca2+]i), the experimental design was repeated in mice expressing podocyte-specific Ca2+ sensor. MMF ameliorated the proteinuria and crescent formation induced by NTS. We identified significant changes in the abundance of proteins involved in Ca2+ signaling and actin cytoskeleton regulation, which was further confirmed by direct [Ca2+]i imaging in podocytes showing decreased Ca2+ levels after MMF treatment. This was associated with a tendency to restoration of podocyte foot process structure. Here, we provide evidence that MPA has a substantial direct effect on podocytes. MMF contributes to improvement of [Ca2+]i and amelioration of the disorganized actin cytoskeleton in podocytes. These data extend the knowledge of direct effects of immunosuppressants on podocytes that may contribute to a more effective treatment of proteinuric glomerulopathies with the least possible side effects.
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Affiliation(s)
- A Hackl
- Department of Pediatrics, Faculty of Medicine, University Hospital Cologne, University of Cologne, Kerpener Street 62, 50937, Cologne, Germany.
- CECAD, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany.
| | - E Nüsken
- Department of Pediatrics, Faculty of Medicine, University Hospital Cologne, University of Cologne, Kerpener Street 62, 50937, Cologne, Germany
| | - J Voggel
- Department of Pediatrics, Faculty of Medicine, University Hospital Cologne, University of Cologne, Kerpener Street 62, 50937, Cologne, Germany
| | - S E D Abo Zed
- Department of Pediatrics, Faculty of Medicine, University Hospital Cologne, University of Cologne, Kerpener Street 62, 50937, Cologne, Germany
- CECAD, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
| | - J Binz-Lotter
- CECAD, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
- Department 2 of Internal Medicine, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
| | - D Unnersjö-Jess
- CECAD, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
- Department 2 of Internal Medicine, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
| | - C Müller
- Department of Therapeutic Drug Monitoring, Pharmacology at the Laboratory Centre, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
| | - G Fink
- Department of Pediatrics, Faculty of Medicine, University Hospital Cologne, University of Cologne, Kerpener Street 62, 50937, Cologne, Germany
| | - K Bohl
- CECAD, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
- Department 2 of Internal Medicine, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
| | - E Wiesner
- CECAD, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
- Department 2 of Internal Medicine, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
| | - P Diefenhardt
- CECAD, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
- Department 2 of Internal Medicine, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
| | - C Dafinger
- Department of Pediatrics, Faculty of Medicine, University Hospital Cologne, University of Cologne, Kerpener Street 62, 50937, Cologne, Germany
- CECAD, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
| | - H Chen
- CECAD, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
- Department 2 of Internal Medicine, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
| | - M Wohlfarth
- Department of Pediatrics, Faculty of Medicine, University Hospital Cologne, University of Cologne, Kerpener Street 62, 50937, Cologne, Germany
| | - R-U Müller
- CECAD, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
- Department 2 of Internal Medicine, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
- Center for Rare Kidney Diseases Cologne, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
| | - M J Hackl
- CECAD, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
- Department 2 of Internal Medicine, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
| | - B Schermer
- CECAD, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
- Department 2 of Internal Medicine, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
| | - K-D Nüsken
- Department of Pediatrics, Faculty of Medicine, University Hospital Cologne, University of Cologne, Kerpener Street 62, 50937, Cologne, Germany
| | - L T Weber
- Department of Pediatrics, Faculty of Medicine, University Hospital Cologne, University of Cologne, Kerpener Street 62, 50937, Cologne, Germany
- Center for Rare Kidney Diseases Cologne, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
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11
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Rogg M, Maier JI, Helmstädter M, Sammarco A, Kliewe F, Kretz O, Weißer L, Van Wymersch C, Findeisen K, Koessinger AL, Tsoy O, Baumbach J, Grabbert M, Werner M, Huber TB, Endlich N, Schilling O, Schell C. A YAP/TAZ-ARHGAP29-RhoA Signaling Axis Regulates Podocyte Protrusions and Integrin Adhesions. Cells 2023; 12:1795. [PMID: 37443829 PMCID: PMC10340513 DOI: 10.3390/cells12131795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 06/28/2023] [Accepted: 07/01/2023] [Indexed: 07/15/2023] Open
Abstract
Glomerular disease due to podocyte malfunction is a major factor in the pathogenesis of chronic kidney disease. Identification of podocyte-specific signaling pathways is therefore a prerequisite to characterizing relevant disease pathways and developing novel treatment approaches. Here, we employed loss of function studies for EPB41L5 (Yurt) as a central podocyte gene to generate a cell type-specific disease model. Loss of Yurt in fly nephrocytes caused protein uptake and slit diaphragm defects. Transcriptomic and proteomic analysis of human EPB41L5 knockout podocytes demonstrated impaired mechanotransduction via the YAP/TAZ signaling pathway. Further analysis of specific inhibition of the YAP/TAZ-TEAD transcription factor complex by TEADi led to the identification of ARGHAP29 as an EPB41L5 and YAP/TAZ-dependently expressed podocyte RhoGAP. Knockdown of ARHGAP29 caused increased RhoA activation, defective lamellipodia formation, and increased maturation of integrin adhesion complexes, explaining similar phenotypes caused by loss of EPB41L5 and TEADi expression in podocytes. Detection of increased levels of ARHGAP29 in early disease stages of human glomerular disease implies a novel negative feedback loop for mechanotransductive RhoA-YAP/TAZ signaling in podocyte physiology and disease.
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Affiliation(s)
- Manuel Rogg
- Institute of Surgical Pathology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Jasmin I. Maier
- Institute of Surgical Pathology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Martin Helmstädter
- Department of Medicine IV, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Alena Sammarco
- Institute of Surgical Pathology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Felix Kliewe
- Department of Anatomy and Cell Biology, University Medicine Greifswald, 17489 Greifswald, Germany (N.E.)
| | - Oliver Kretz
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Lisa Weißer
- Institute of Surgical Pathology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Clara Van Wymersch
- Institute of Surgical Pathology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Karla Findeisen
- Institute of Surgical Pathology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Anna L. Koessinger
- Institute of Surgical Pathology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Olga Tsoy
- Institute for Computational Systems Biology, University of Hamburg, 22607 Hamburg, Germany; (O.T.)
| | - Jan Baumbach
- Institute for Computational Systems Biology, University of Hamburg, 22607 Hamburg, Germany; (O.T.)
- Department of Mathematics and Computer Science, University of Southern Denmark, 5230 Odense, Denmark
| | - Markus Grabbert
- Department of Urology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Martin Werner
- Institute of Surgical Pathology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Tobias B. Huber
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Nicole Endlich
- Department of Anatomy and Cell Biology, University Medicine Greifswald, 17489 Greifswald, Germany (N.E.)
| | - Oliver Schilling
- Institute of Surgical Pathology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
- Freiburg Institute for Advanced Studies (FRIAS), University of Freiburg, 79106 Freiburg, Germany
| | - Christoph Schell
- Institute of Surgical Pathology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
- Freiburg Institute for Advanced Studies (FRIAS), University of Freiburg, 79106 Freiburg, Germany
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12
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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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13
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Späth MR, Hoyer-Allo KJR, Seufert L, Höhne M, Lucas C, Bock T, Isermann L, Brodesser S, Lackmann JW, Kiefer K, Koehler FC, Bohl K, Ignarski M, Schiller P, Johnsen M, Kubacki T, Grundmann F, Benzing T, Trifunovic A, Krüger M, Schermer B, Burst V, Müller RU. Organ Protection by Caloric Restriction Depends on Activation of the De Novo NAD+ Synthesis Pathway. J Am Soc Nephrol 2023; 34:772-792. [PMID: 36758124 PMCID: PMC10125653 DOI: 10.1681/asn.0000000000000087] [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: 03/20/2022] [Accepted: 01/10/2023] [Indexed: 02/11/2023] Open
Abstract
SIGNIFICANCE STATEMENT AKI is a major clinical complication leading to high mortality, but intensive research over the past decades has not led to targeted preventive or therapeutic measures. In rodent models, caloric restriction (CR) and transient hypoxia significantly prevent AKI and a recent comparative transcriptome analysis of murine kidneys identified kynureninase (KYNU) as a shared downstream target. The present work shows that KYNU strongly contributes to CR-mediated protection as a key player in the de novo nicotinamide adenine dinucleotide biosynthesis pathway. Importantly, the link between CR and NAD+ biosynthesis could be recapitulated in a human cohort. BACKGROUND Clinical practice lacks strategies to treat AKI. Interestingly, preconditioning by hypoxia and caloric restriction (CR) is highly protective in rodent AKI models. However, the underlying molecular mechanisms of this process are unknown. METHODS Kynureninase (KYNU) knockout mice were generated by Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and comparative transcriptome, proteome and metabolite analyses of murine kidneys pre- and post-ischemia-reperfusion injury in the context of CR or ad libitum diet were performed. In addition, acetyl-lysin enrichment and mass spectrometry were used to assess protein acetylation. RESULTS We identified KYNU as a downstream target of CR and show that KYNU strongly contributes to the protective effect of CR. The KYNU-dependent de novo nicotinamide adenine dinucleotide (NAD+) biosynthesis pathway is necessary for CR-associated maintenance of NAD+ levels. This finding is associated with reduced protein acetylation in CR-treated animals, specifically affecting enzymes in energy metabolism. Importantly, the effect of CR on de novo NAD+ biosynthesis pathway metabolites can be recapitulated in humans. CONCLUSIONS CR induces the de novo NAD+ synthesis pathway in the context of IRI and is essential for its full nephroprotective potential. Differential protein acetylation may be the molecular mechanism underlying the relationship of NAD+, CR, and nephroprotection.
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Affiliation(s)
- Martin R. Späth
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- CECAD, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - K. Johanna R. Hoyer-Allo
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- CECAD, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Lisa Seufert
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- CECAD, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Martin Höhne
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Christina Lucas
- CECAD, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Theresa Bock
- CECAD, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- Institute of Genetics, University of Cologne, Cologne, Germany
| | - Lea Isermann
- CECAD, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- Medical Faculty, Institute for Mitochondrial Diseases and Aging, University of Cologne, Cologne, Germany
- Center for Molecular Medicine (CMMC), University of Cologne, Cologne, Germany
| | - Susanne Brodesser
- CECAD, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Jan-Wilm Lackmann
- CECAD, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Katharina Kiefer
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- CECAD, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Felix C. Koehler
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- CECAD, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Katrin Bohl
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- CECAD, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Michael Ignarski
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- CECAD, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Petra Schiller
- Institute of Medical Statistics and Computational Biology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Marc Johnsen
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- CECAD, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Torsten Kubacki
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- CECAD, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Franziska Grundmann
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Thomas Benzing
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- CECAD, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Aleksandra Trifunovic
- CECAD, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- Medical Faculty, Institute for Mitochondrial Diseases and Aging, University of Cologne, Cologne, Germany
- Center for Molecular Medicine (CMMC), University of Cologne, Cologne, Germany
| | - Marcus Krüger
- CECAD, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- Institute of Genetics, University of Cologne, Cologne, Germany
- Center for Molecular Medicine (CMMC), University of Cologne, Cologne, Germany
| | - Bernhard Schermer
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- CECAD, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Volker Burst
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- Emergency Department, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Roman-Ulrich Müller
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- CECAD, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
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14
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Kylies D, Zimmermann M, Haas F, Schwerk M, Kuehl M, Brehler M, Czogalla J, Hernandez LC, Konczalla L, Okabayashi Y, Menzel J, Edenhofer I, Mezher S, Aypek H, Dumoulin B, Wu H, Hofmann S, Kretz O, Wanner N, Tomas NM, Krasemann S, Glatzel M, Kuppe C, Kramann R, Banjanin B, Schneider RK, Urbschat C, Arck P, Gagliani N, van Zandvoort M, Wiech T, Grahammer F, Sáez PJ, Wong MN, Bonn S, Huber TB, Puelles VG. Expansion-enhanced super-resolution radial fluctuations enable nanoscale molecular profiling of pathology specimens. NATURE NANOTECHNOLOGY 2023; 18:336-342. [PMID: 37037895 PMCID: PMC10115634 DOI: 10.1038/s41565-023-01328-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 01/13/2023] [Indexed: 06/19/2023]
Abstract
Expansion microscopy physically enlarges biological specimens to achieve nanoscale resolution using diffraction-limited microscopy systems1. However, optimal performance is usually reached using laser-based systems (for example, confocal microscopy), restricting its broad applicability in clinical pathology, as most centres have access only to light-emitting diode (LED)-based widefield systems. As a possible alternative, a computational method for image resolution enhancement, namely, super-resolution radial fluctuations (SRRF)2,3, has recently been developed. However, this method has not been explored in pathology specimens to date, because on its own, it does not achieve sufficient resolution for routine clinical use. Here, we report expansion-enhanced super-resolution radial fluctuations (ExSRRF), a simple, robust, scalable and accessible workflow that provides a resolution of up to 25 nm using LED-based widefield microscopy. ExSRRF enables molecular profiling of subcellular structures from archival formalin-fixed paraffin-embedded tissues in complex clinical and experimental specimens, including ischaemic, degenerative, neoplastic, genetic and immune-mediated disorders. Furthermore, as examples of its potential application to experimental and clinical pathology, we show that ExSRRF can be used to identify and quantify classical features of endoplasmic reticulum stress in the murine ischaemic kidney and diagnostic ultrastructural features in human kidney biopsies.
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Affiliation(s)
- Dominik Kylies
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Research Center On Rare Kidney Diseases (RECORD), University Hospital Erlangen, Erlangen, Germany
| | - Marina Zimmermann
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Institute of Medical Systems Biology, Center for Biomedical AI (bAIome), Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Fabian Haas
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Maria Schwerk
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Malte Kuehl
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Institute of Medical Systems Biology, Center for Biomedical AI (bAIome), Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Michael Brehler
- Institute of Medical Systems Biology, Center for Biomedical AI (bAIome), Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jan Czogalla
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Lola C Hernandez
- Cell Communication and Migration Laboratory, Department of Biochemistry and Molecular Cell Biology (IBMZ), Center for Experimental Medicine, Hamburg, Germany
| | - Leonie Konczalla
- Department of General, Visceral and Thoracic Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Mildred Scheel Cancer Career Center HaTriCS4, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Yusuke Okabayashi
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | | | - Ilka Edenhofer
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Sam Mezher
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Hande Aypek
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Bernhard Dumoulin
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Hui Wu
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Smilla Hofmann
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Oliver Kretz
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Nicola Wanner
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Nicola M Tomas
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Susanne Krasemann
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Markus Glatzel
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christoph Kuppe
- Institute of Experimental Medicine and Systems Biology and Division of Nephrology and Clinical Immunology, RWTH Aachen University Medical Faculty, Aachen, Germany
| | - Rafael Kramann
- Institute of Experimental Medicine and Systems Biology and Division of Nephrology and Clinical Immunology, RWTH Aachen University Medical Faculty, Aachen, Germany
| | - Bella Banjanin
- Department of Developmental Biology, Erasmus Medical Center, Rotterdam, The Netherlands
- Oncode Institute, Erasmus Medical Center Cancer Institute, Rotterdam, The Netherlands
| | - Rebekka K Schneider
- Department of Developmental Biology, Erasmus Medical Center, Rotterdam, The Netherlands
- Oncode Institute, Erasmus Medical Center Cancer Institute, Rotterdam, The Netherlands
- Institute for Cell and Tumor Biology, RWTH Aachen University, Aachen, Germany
| | - Christopher Urbschat
- Department of Obstetrics and Fetal Medicine, Division of Experimental Feto-Maternal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Petra Arck
- Department of Obstetrics and Fetal Medicine, Division of Experimental Feto-Maternal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Nicola Gagliani
- Department of General, Visceral and Thoracic Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Marc van Zandvoort
- Department of Genetics and Cell Biology, Maastricht University, School for Oncology and Reproduction GROW, School for Mental Health and Neuroscience MHeNS, and School for Cardiovascular Diseases CARIM, Maastricht University, Maastricht, The Netherlands
- Institute for Molecular Cardiovascular Research (IMCAR), RWTH Aachen University, Aachen, Germany
| | - Thorsten Wiech
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - 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
| | - Pablo J Sáez
- Cell Communication and Migration Laboratory, Department of Biochemistry and Molecular Cell Biology (IBMZ), Center for Experimental Medicine, Hamburg, Germany
| | - Milagros N Wong
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Pathology, Aarhus University Hospital, Aarhus, Denmark
| | - Stefan Bonn
- Institute of Medical Systems Biology, Center for Biomedical AI (bAIome), Center for Molecular Neurobiology Hamburg (ZMNH), 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
| | - Victor G Puelles
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
- Department of Pathology, Aarhus University Hospital, Aarhus, Denmark.
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15
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Caza TN, Storey AJ, Hassen SI, Herzog C, Edmondson RD, Arthur JM, Kenan DJ, Larsen CP. Discovery of seven novel putative antigens in membranous nephropathy and membranous lupus nephritis identified by mass spectrometry. Kidney Int 2023; 103:593-606. [PMID: 36638888 PMCID: PMC9974866 DOI: 10.1016/j.kint.2023.01.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Revised: 12/28/2022] [Accepted: 01/04/2023] [Indexed: 01/12/2023]
Abstract
Multiple autoantigens have been identified in membranous nephropathy (MN) by tissue-based proteomics. However, antigenic targets of disease are unknown for over 10% of patients with MN and over half of those with membranous lupus nephritis (MLN). Here, we identified multiple new targets in PLA2R-/THSD7A-/EXT-/NELL1-quadruple negative MN biopsies through mass spectrometry of immune complexes recovered from biopsy tissue of patients with MN. Patients with MN negative for these four antigens were identified from Arkana Laboratories case archives. Protein G immunoprecipitation recovered immune complexes from frozen biopsy tissue from 142 quadruple-negative cases and 278 cases of known antigen type, followed by interrogation by mass spectrometry. Potential putative antigens were confirmed through paraffin immunofluorescence and co-localization with IgG within immune deposits. Consecutive series of 165 cases of PLA2R-negative MN and 142 MLN biopsies were screened to determine the frequency for each potential antigen. Seven putative antigens were discovered within immune complexes from biopsies of patients with MN including FCN3, CD206, EEA1, SEZ6L2, NPR3, MST1, and VASN. Peptides from these proteins were not enriched in the 278 cases of known antigen type. Between three to 30 unique peptides were detected for each new target. Frequencies of each biomarker, determined by staining consecutive case series, ranged from under 1 to 4.9%. NPR3 and CD206 were only positive in index cases. All cases showed co-localization of IgG within the immune deposits. Thus, seven putative antigens were newly identified in MN and MLN. Due to the number of antigens identified, it is becoming impractical to type PLA2R-negative MN or MLN cases through immunostaining alone. A multiplex approach is needed for subtyping of these diseases.
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Affiliation(s)
| | - Aaron J Storey
- Division of Nephrology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | | | - Christian Herzog
- Division of Nephrology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Rick D Edmondson
- Division of Nephrology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - John M Arthur
- Division of Nephrology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
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16
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Tomas NM, Dehde S, Meyer-Schwesinger C, Huang M, Hermans-Borgmeyer I, Maybaum J, Lucas R, von der Heide JL, Kretz O, Köllner SMS, Seifert L, Huber TB, Zahner G. Podocyte expression of human phospholipase A2 receptor 1 causes immune-mediated membranous nephropathy in mice. Kidney Int 2023; 103:297-303. [PMID: 36191868 DOI: 10.1016/j.kint.2022.09.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 09/12/2022] [Accepted: 09/22/2022] [Indexed: 01/27/2023]
Abstract
Antibody-mediated autoimmune pathologies like membranous nephropathy are difficult to model, particularly in the absence of local target antigen expression in model organisms such as mice and rats; as is the case for phospholipase A2 receptor 1 (PLA2R1), the major autoantigen in membranous nephropathy. Here, we generated a transgenic mouse line expressing the full-length human PLA2R1 in podocytes, which has no kidney impairment after birth. Beginning from the age of three weeks, these mice spontaneously developed anti-human PLA2R1 antibodies, a nephrotic syndrome with progressive albuminuria and hyperlipidemia, and the typical morphological signs of membranous nephropathy with granular glomerular deposition of murine IgG in immunofluorescence and subepithelial electron-dense deposits by electron microscopy. Importantly, human PLA2R1-expressing Rag2-/- mice, which lack mature and functioning B and T lymphocytes, developed neither anti-PLA2R1 antibodies nor proteinuria. Thus, our work demonstrates that podocyte expression of human PLA2R1 can induce membranous nephropathy with an underlying antibody-mediated pathogenesis in mice. Importantly, this antibody-mediated model enables proof-of-concept evaluations of antigen-specific treatment strategies, e.g., targeting autoantibodies or autoantibody-producing cells, and may further help understand the autoimmune pathogenesis of membranous nephropathy.
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Affiliation(s)
- Nicola M Tomas
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
| | - Silke Dehde
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Catherine Meyer-Schwesinger
- Institute of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ming Huang
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Irm Hermans-Borgmeyer
- Center of Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Johanna Maybaum
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Renke Lucas
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jennie L von der Heide
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Oliver Kretz
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Sarah M S Köllner
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Larissa Seifert
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Tobias B Huber
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Gunther Zahner
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
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17
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Network-Based Assessment of Minimal Change Disease Identifies Glomerular Response to IL-7 and IL-12 Pathways Activation as Innovative Treatment Target. Biomedicines 2023; 11:biomedicines11010226. [PMID: 36672735 PMCID: PMC9856051 DOI: 10.3390/biomedicines11010226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 12/20/2022] [Accepted: 01/07/2023] [Indexed: 01/18/2023] Open
Abstract
Background: Minimal change disease (MCD), a major cause of nephrotic syndrome, is usually treated by corticosteroid administration. MCD unresponsiveness to therapy and recurrences are nonetheless frequently observed, particularly in adults. To explore MCD-related pathogenetic mechanisms and to identify novel drug targets ultimately contributing to novel therapeutic avenues with a certain specificity for MCD, we compared glomerular transcriptomes from MCD with membranous nephropathy (MN) patients and healthy controls. Methods: Renal biopsies from adult patients with MCD (n = 14) or MN (n = 12), and non-diseased controls (n = 8) were selected from the Norwegian Kidney Biopsy Registry. RNA for 75 base-pair paired-end RNASeq were obtained from laser capture micro-dissected (LCM) glomeruli from FFPE sections. Transcriptional landscapes were computed by combining pathway-centered analyses and network science methodologies that integrate multiple bioinformatics resources. Results: Compared to normal glomeruli, cells from MCD displayed an inflammatory signature apparently governed by the IL1 and IL7 systems. While enrichment of IL1 production and secretion was a shared feature of MCD and MN compared to normal tissue, responses involving IL7 pathway activation were unique to MCD. Indeed, IL7R expressed by glomeruli was the most upregulated gene of the interleukin family in MCD versus normal controls. IL7 pathway activation was paralleled by significant enrichment in adaptive immune system processes and transcriptional regulation and depletion in pathways related to energy metabolism and transcription. Downregulation of these organ function-related themes again occurred predominately in MCD and was significantly less pronounced in MN. Immunofluorescence and immunohistochemistry, respectively, confirmed the expression of phosphorylated IL-7 receptor alpha (IL7RA, CD127) and IL12 receptor beta 1 (IL12RB1) proteins. Conclusions: Gene expression profiling of archival FFPE-biopsies identifies MCD-specific signatures with IL7RA and IL12RB1 as novel targets for MCD treatment.
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18
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Chung EYM, Wang YM, Keung K, Hu M, McCarthy H, Wong G, Kairaitis L, Bose B, Harris DCH, Alexander SI. Membranous nephropathy: Clearer pathology and mechanisms identify potential strategies for treatment. Front Immunol 2022; 13:1036249. [PMID: 36405681 PMCID: PMC9667740 DOI: 10.3389/fimmu.2022.1036249] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Accepted: 10/19/2022] [Indexed: 11/07/2022] Open
Abstract
Primary membranous nephropathy (PMN) is one of the common causes of adult-onset nephrotic syndrome and is characterized by autoantibodies against podocyte antigens causing in situ immune complex deposition. Much of our understanding of the disease mechanisms underpinning this kidney-limited autoimmune disease originally came from studies of Heymann nephritis, a rat model of PMN, where autoantibodies against megalin produced a similar disease phenotype though megalin is not implicated in human disease. In PMN, the major target antigen was identified to be M-type phospholipase A2 receptor 1 (PLA2R) in 2009. Further utilization of mass spectrometry on immunoprecipitated glomerular extracts and laser micro dissected glomeruli has allowed the rapid discovery of other antigens (thrombospondin type-1 domain-containing protein 7A, neural epidermal growth factor-like 1 protein, semaphorin 3B, protocadherin 7, high temperature requirement A serine peptidase 1, netrin G1) targeted by autoantibodies in PMN. Despite these major advances in our understanding of the pathophysiology of PMN, treatments remain non-specific, often ineffective, or toxic. In this review, we summarize our current understanding of the immune mechanisms driving PMN from animal models and clinical studies, and the implications on the development of future targeted therapeutic strategies.
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Affiliation(s)
- Edmund Y. M. Chung
- Centre for Kidney Research, The Children’s Hospital at Westmead, Westmead, NSW, Australia
| | - Yuan M. Wang
- Centre for Kidney Research, The Children’s Hospital at Westmead, Westmead, NSW, Australia
| | - Karen Keung
- Department of Nephrology, Prince of Wales Hospital, Randwick, NSW, Australia
| | - Min Hu
- The Centre for Transplant and Renal Research, Westmead Institute of Medical Research, Westmead, NSW, Australia
| | - Hugh McCarthy
- Centre for Kidney Research, The Children’s Hospital at Westmead, Westmead, NSW, Australia
- Department of Nephrology, The Children’s Hospital at Westmead, Westmead, NSW, Australia
- Department of Nephrology, Sydney Children’s Hospital, Randwick, NSW, Australia
| | - Germaine Wong
- Centre for Kidney Research, The Children’s Hospital at Westmead, Westmead, NSW, Australia
- Department of Nephrology, Westmead Hospital, Westmead, NSW, Australia
| | - Lukas Kairaitis
- Department of Nephrology, Blacktown Hospital, Blacktown, NSW, Australia
| | - Bhadran Bose
- Department of Nephrology, Nepean Hospital, Kingswood, NSW, Australia
| | - David C. H. Harris
- The Centre for Transplant and Renal Research, Westmead Institute of Medical Research, Westmead, NSW, Australia
- Department of Nephrology, Westmead Hospital, Westmead, NSW, Australia
| | - Stephen I. Alexander
- Centre for Kidney Research, The Children’s Hospital at Westmead, Westmead, NSW, Australia
- Department of Nephrology, The Children’s Hospital at Westmead, Westmead, NSW, Australia
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19
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A slit-diaphragm-associated protein network for dynamic control of renal filtration. Nat Commun 2022; 13:6446. [PMID: 36307401 PMCID: PMC9616960 DOI: 10.1038/s41467-022-33748-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 09/29/2022] [Indexed: 12/25/2022] Open
Abstract
The filtration of blood in the kidney which is crucial for mammalian life is determined by the slit-diaphragm, a cell-cell junction between the foot processes of renal podocytes. The slit-diaphragm is thought to operate as final barrier or as molecular sensor of renal filtration. Using high-resolution proteomic analysis of slit-diaphragms affinity-isolated from rodent kidney, we show that the native slit-diaphragm is built from the junction-forming components Nephrin, Neph1 and Podocin and a co-assembled high-molecular weight network of proteins. The network constituents cover distinct classes of proteins including signaling-receptors, kinases/phosphatases, transporters and scaffolds. Knockout or knock-down of either the core components or the selected network constituents tyrosine kinase MER (MERTK), atrial natriuretic peptide-receptor C (ANPRC), integral membrane protein 2B (ITM2B), membrane-associated guanylate-kinase, WW and PDZ-domain-containing protein1 (MAGI1) and amyloid protein A4 resulted in target-specific impairment or disruption of the filtration process. Our results identify the slit-diaphragm as a multi-component system that is endowed with context-dependent dynamics via a co-assembled protein network.
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20
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Lausecker F, Koehler S, Fresquet M, Naylor RW, Tian P, Wanner N, Braun F, Butt L, Huber TB, Lennon R. Integrating basic science with translational research: the 13th International Podocyte Conference 2021. Kidney Int 2022; 102:708-719. [PMID: 35964799 PMCID: PMC9386279 DOI: 10.1016/j.kint.2022.07.021] [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: 05/12/2022] [Revised: 07/20/2022] [Accepted: 07/26/2022] [Indexed: 11/30/2022]
Abstract
The 13th International Podocyte Conference was held in Manchester, UK, and online from July 28 to 30, 2021. Originally planned for 2020, this biannual meeting was postponed by a year because of the coronavirus disease 2019 (COVID-19) pandemic and proceeded as an innovative hybrid meeting. In addition to in-person attendance, online registration was offered, and this attracted 490 conference registrations in total. As a Podocyte Conference first, a day for early-career researchers was introduced. This premeeting included talks from graduate students and postdoctoral researchers. It gave early career researchers the opportunity to ask a panel, comprising academic leaders and journal editors, about career pathways and the future for podocyte research. The main meeting over 3 days included a keynote talk and 4 focused sessions each day incorporating invited talks, followed by selected abstract presentations, and an open panel discussion. The conference concluded with a Patient Day, which brought together patients, clinicians, researchers, and industry representatives. The Patient Day was an interactive and diverse day. As well as updates on improving diagnosis and potential new therapies, the Patient Day included a PodoArt competition, exercise and cooking classes with practical nutrition advice, and inspirational stories from patients and family members. This review summarizes the exciting science presented during the 13th International Podocyte Conference and demonstrates the resilience of researchers during a global pandemic.
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Affiliation(s)
- Franziska Lausecker
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Sybille Koehler
- Biomedical Sciences, University of Edinburgh, Edinburgh, UK; III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Maryline Fresquet
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Richard W Naylor
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Pinyuan Tian
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Nicola Wanner
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Fabian Braun
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Linus Butt
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Tobias B Huber
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
| | - Rachel Lennon
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK; Department of Paediatric Nephrology, Royal Manchester Children's Hospital, Manchester University Hospitals National Health Service (NHS) Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK.
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21
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Martin CE, Phippen NJ, Keyvani Chahi A, Tilak M, Banerjee SL, Lu P, New LA, Williamson CR, Platt MJ, Simpson JA, Krendel M, Bisson N, Gingras AC, Jones N. Complementary Nck1/2 Signaling in Podocytes Controls α Actinin-4-Mediated Actin Organization, Adhesion, and Basement Membrane Composition. J Am Soc Nephrol 2022; 33:1546-1567. [PMID: 35906089 PMCID: PMC9342632 DOI: 10.1681/asn.2021101343] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 04/26/2022] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Maintenance of the kidney filtration barrier requires coordinated interactions between podocytes and the underlying glomerular basement membrane (GBM). GBM ligands bind podocyte integrins, which triggers actin-based signaling events critical for adhesion. Nck1/2 adaptors have emerged as essential regulators of podocyte cytoskeletal dynamics. However, the precise signaling mechanisms mediated by Nck1/2 adaptors in podocytes remain to be fully elucidated. METHODS We generated podocytes deficient in Nck1 and Nck2 and used transcriptomic approaches to profile expression differences. Proteomic techniques identified specific binding partners for Nck1 and Nck2 in podocytes. We used cultured podocytes and mice deficient in Nck1 and/or Nck2, along with podocyte injury models, to comprehensively verify our findings. RESULTS Compound loss of Nck1/2 altered expression of genes involved in actin binding, cell adhesion, and extracellular matrix composition. Accordingly, Nck1/2-deficient podocytes showed defects in actin organization and cell adhesion in vitro, with podocyte detachment and altered GBM morphology present in vivo. We identified distinct interactomes for Nck1 and Nck2 and uncovered a mechanism by which Nck1 and Nck2 cooperate to regulate actin bundling at focal adhesions via α actinin-4. Furthermore, loss of Nck1 or Nck2 resulted in increased matrix deposition in vivo, with more prominent defects in Nck2-deficient mice, consistent with enhanced susceptibility to podocyte injury. CONCLUSION These findings reveal distinct, yet complementary, roles for Nck proteins in regulating podocyte adhesion, controlling GBM composition, and sustaining filtration barrier integrity.
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Affiliation(s)
- Claire E Martin
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada.,Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario, Canada
| | - Noah J Phippen
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Ava Keyvani Chahi
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada.,Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Manali Tilak
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Sara L Banerjee
- Division of Oncology, Centre de Recherche du Centre Hospitalier Universitaire de Quebec-Laval University, Quebec City, Quebec, Canada.,Centre de Recherche sur le Cancer de l'Université Laval, Quebec City, Quebec, Canada
| | - Peihua Lu
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Laura A New
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Casey R Williamson
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Mathew J Platt
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, Ontario, Canada
| | - Jeremy A Simpson
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, Ontario, Canada
| | - Mira Krendel
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, New York
| | - Nicolas Bisson
- Division of Oncology, Centre de Recherche du Centre Hospitalier Universitaire de Quebec-Laval University, Quebec City, Quebec, Canada.,Centre de Recherche sur le Cancer de l'Université Laval, Quebec City, Quebec, Canada.,PROTEO-Quebec Network for Research on Protein Function, Engineering, and Applications Department of Molecular Biology, Medical Biochemistry and Pathology, Laval University, Quebec City, Quebec, Canada
| | - Anne-Claude Gingras
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Nina Jones
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
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22
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Rinschen MM, Palygin O, El-Meanawy A, Domingo-Almenara X, Palermo A, Dissanayake LV, Golosova D, Schafroth MA, Guijas C, Demir F, Jaegers J, Gliozzi ML, Xue J, Hoehne M, Benzing T, Kok BP, Saez E, Bleich M, Himmerkus N, Weisz OA, Cravatt BF, Krüger M, Benton HP, Siuzdak G, Staruschenko A. Accelerated lysine metabolism conveys kidney protection in salt-sensitive hypertension. Nat Commun 2022; 13:4099. [PMID: 35835746 PMCID: PMC9283537 DOI: 10.1038/s41467-022-31670-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 06/27/2022] [Indexed: 01/07/2023] Open
Abstract
Hypertension and kidney disease have been repeatedly associated with genomic variants and alterations of lysine metabolism. Here, we combined stable isotope labeling with untargeted metabolomics to investigate lysine's metabolic fate in vivo. Dietary 13C6 labeled lysine was tracked to lysine metabolites across various organs. Globally, lysine reacts rapidly with molecules of the central carbon metabolism, but incorporates slowly into proteins and acylcarnitines. Lysine metabolism is accelerated in a rat model of hypertension and kidney damage, chiefly through N-alpha-mediated degradation. Lysine administration diminished development of hypertension and kidney injury. Protective mechanisms include diuresis, further acceleration of lysine conjugate formation, and inhibition of tubular albumin uptake. Lysine also conjugates with malonyl-CoA to form a novel metabolite Nε-malonyl-lysine to deplete malonyl-CoA from fatty acid synthesis. Through conjugate formation and excretion as fructoselysine, saccharopine, and Nε-acetyllysine, lysine lead to depletion of central carbon metabolites from the organism and kidney. Consistently, lysine administration to patients at risk for hypertension and kidney disease inhibited tubular albumin uptake, increased lysine conjugate formation, and reduced tricarboxylic acid (TCA) cycle metabolites, compared to kidney-healthy volunteers. In conclusion, lysine isotope tracing mapped an accelerated metabolism in hypertension, and lysine administration could protect kidneys in hypertensive kidney disease.
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Affiliation(s)
- Markus M Rinschen
- Scripps Center for Metabolomics, Scripps Research, La Jolla, CA, 92037, USA.
- Department of Biomedicine, Aarhus University, Aarhus, Denmark.
- III. Medical Clinic, University Hospital Hamburg Eppendorf, Hamburg, Germany.
- AIAS, Aarhus Institute of Advanced Studies (AIAS), Aarhus University, Aarhus, Denmark.
| | - Oleg Palygin
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Ashraf El-Meanawy
- Division of Nephrology, Department of Medicine, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Xavier Domingo-Almenara
- Scripps Center for Metabolomics, Scripps Research, La Jolla, CA, 92037, USA
- Omics Sciences Unit, EURECAT, Technology Centre of Catalonia, Reus, Catalonia, Spain
| | - Amelia Palermo
- Scripps Center for Metabolomics, Scripps Research, La Jolla, CA, 92037, USA
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, USA
| | - Lashodya V Dissanayake
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL, 33602, USA
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Daria Golosova
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | | | - Carlos Guijas
- Scripps Center for Metabolomics, Scripps Research, La Jolla, CA, 92037, USA
| | - Fatih Demir
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | | | - Megan L Gliozzi
- Renal Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15261, USA
| | - Jingchuan Xue
- Scripps Center for Metabolomics, Scripps Research, La Jolla, CA, 92037, USA
| | - Martin Hoehne
- Center for Molecular Medicine Cologne, Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, Cologne, Germany
- Department II of Internal Medicine, University Hospital of Cologne, Cologne, Germany
| | - Thomas Benzing
- Center for Molecular Medicine Cologne, Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, Cologne, Germany
- Department II of Internal Medicine, University Hospital of Cologne, Cologne, Germany
| | - Bernard P Kok
- Department of Molecular Medicine, Scripps Research, La Jolla, CA, 92037, USA
| | - Enrique Saez
- Department of Molecular Medicine, Scripps Research, La Jolla, CA, 92037, USA
| | - Markus Bleich
- Institute of Physiology, University Kiel, Kiel, Germany
| | | | - Ora A Weisz
- Renal Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15261, USA
| | | | - Marcus Krüger
- Center for Molecular Medicine Cologne, Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, Cologne, Germany
| | - H Paul Benton
- Scripps Center for Metabolomics, Scripps Research, La Jolla, CA, 92037, USA
| | - Gary Siuzdak
- Scripps Center for Metabolomics, Scripps Research, La Jolla, CA, 92037, USA.
| | - Alexander Staruschenko
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL, 33602, USA.
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA.
- James A. Haley Veterans' Hospital, Tampa, FL, 33612, USA.
- Hypertension and Kidney Research Center, University of South Florida, Tampa, FL, 33602, USA.
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23
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Hutzfeldt AD, Tan Y, Bonin LL, Beck BB, Baumbach J, Lassé M, Demir F, Rinschen MM. Consensus draft of the native mouse podocyte-ome. Am J Physiol Renal Physiol 2022; 323:F182-F197. [PMID: 35796460 DOI: 10.1152/ajprenal.00058.2022] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The podocyte is a key cell in maintaining renal filtration barrier integrity. Several recent studies have analyzed the entity of genome-coded molecules in the podocyte at deep resolution. This avenue of "podocyte-ome" research was enabled by a variety of techniques, including single-cell transcriptomics, FACS-sorting with and without genetically encoded markers, and deep acquisition of proteomics. However, data across various omics studies are not well-integrated with each other. Here, we aim to establish a common, simplified knowledgebase for the mouse "podocyte-ome" by integrating bulk RNA sequencing and bulk proteomics of sorted podocytes and single cell transcriptomics. Three datasets of each omics type from different laboratories, respectively, were integrated, visualized and bioinformatically analyzed. The procedure sheds light on conserved processes of podocytes, but also on limitations and specific features of the used technologies. High expression of glycan GPI anchor synthesis and turnover, and retinol metabolism was identified as a relatively understudied feature of podocytes, while there are both podocyte-enriched and podocyte-depleted actin binding molecules. We compiled aggregated data in an application that illustrates the features of the dataset and allows for exploratory analyses through individual gene query of podocyte identity in absolute and relative quantification towards other glomerular cell types, keywords, GO-terms and gene set enrichments. This consensus draft is a first step towards common molecular omics knowledge of kidney cells.
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Affiliation(s)
- Arvid D Hutzfeldt
- III Department of Medicine, grid.13648.38University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Yifan Tan
- Department of Biomedicine, grid.7048.bAarhus University, Aarhus, Denmark
| | - Léna Lydie Bonin
- Department of Biomedicine, grid.7048.bAarhus University, Aarhus, Denmark
| | - Bodo B Beck
- Institute of Human Genetics, Faculty of Medicine and University Hospital Cologne, grid.6190.eUniversity of Cologne, Cologne, Germany
| | - Jan Baumbach
- Institute for Computational Systems Biology, grid.9026.dUniversität Hamburg, Hamburg, Germany
| | - Moritz Lassé
- III Department of Medicine, grid.13648.38University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Fatih Demir
- Department of Biomedicine, grid.7048.bAarhus University, Aarhus, Denmark
| | - Markus M Rinschen
- Department of Biomedicine, grid.7048.bAarhus University, Aarhus, Denmark
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24
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Aypek H, Krisp C, Lu S, Liu S, Kylies D, Kretz O, Wu G, Moritz M, Amann K, Benz K, Tong P, Hu ZM, Alsulaiman SM, Khan AO, Grohmann M, Wagner T, Müller-Deile J, Schlüter H, Puelles VG, Bergmann C, Huber TB, Grahammer F. Loss of the collagen IV modifier prolyl 3-hydroxylase 2 causes thin basement membrane nephropathy. J Clin Invest 2022; 132:147253. [PMID: 35499085 PMCID: PMC9057608 DOI: 10.1172/jci147253] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 03/16/2022] [Indexed: 01/12/2023] Open
Abstract
The glomerular filtration barrier (GFB) produces primary urine and is composed of a fenestrated endothelium, a glomerular basement membrane (GBM), podocytes, and a slit diaphragm. Impairment of the GFB leads to albuminuria and microhematuria. The GBM is generated via secreted proteins from both endothelial cells and podocytes and is supposed to majorly contribute to filtration selectivity. While genetic mutations or variations of GBM components have been recently proposed to be a common cause of glomerular diseases, pathways modifying and stabilizing the GBM remain incompletely understood. Here, we identified prolyl 3-hydroxylase 2 (P3H2) as a regulator of the GBM in an a cohort of patients with albuminuria. P3H2 hydroxylates the 3' of prolines in collagen IV subchains in the endoplasmic reticulum. Characterization of a P3h2ΔPod mouse line revealed that the absence of P3H2 protein in podocytes induced a thin basement membrane nephropathy (TBMN) phenotype with a thinner GBM than that in WT mice and the development of microhematuria and microalbuminuria over time. Mechanistically, differential quantitative proteomics of the GBM identified a significant decrease in the abundance of collagen IV subchains and their interaction partners in P3h2ΔPod mice. To our knowledge, P3H2 protein is the first identified GBM modifier, and loss or mutation of P3H2 causes TBMN and focal segmental glomerulosclerosis in mice and humans.
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Affiliation(s)
| | - Christoph Krisp
- Institute of Clinical Chemistry and Laboratory Medicine, Mass Spectrometric Proteomics Group, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Shun Lu
- III. Department of Medicine and
| | | | | | | | | | - Manuela Moritz
- Institute of Clinical Chemistry and Laboratory Medicine, Mass Spectrometric Proteomics Group, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Kerstin Amann
- Department of Nephropathology, Institute of Pathology and
| | - Kerstin Benz
- Department of Pediatrics, University of Erlangen, Erlangen, Germany
| | - Ping Tong
- Department of Ophthalmology, The Second Xiangya Hospital and
| | - Zheng-mao Hu
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | | | - Arif O. Khan
- Eye Institute, Cleveland Clinic Abu Dhabi, Abu Dhabi, United Arab Emirates.,Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western University, Cleveland, Ohio, USA
| | - Maik Grohmann
- Medizinische Genetik Mainz, Limbach Genetics, Mainz, Germany
| | - Timo Wagner
- Medizinische Genetik Mainz, Limbach Genetics, Mainz, Germany
| | - Janina Müller-Deile
- Department of Nephrology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Hartmut Schlüter
- Institute of Clinical Chemistry and Laboratory Medicine, Mass Spectrometric Proteomics Group, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - Carsten Bergmann
- Medizinische Genetik Mainz, Limbach Genetics, Mainz, Germany.,Department of Medicine IV, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany
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25
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Jansen J, van den Berge BT, van den Broek M, Maas RJ, Daviran D, Willemsen B, Roverts R, van der Kruit M, Kuppe C, Reimer KC, Di Giovanni G, Mooren F, Nlandu Q, Mudde H, Wetzels R, den Braanker D, Parr N, Nagai JS, Drenic V, Costa IG, Steenbergen E, Nijenhuis T, Dijkman H, Endlich N, van de Kar NCAJ, Schneider RK, Wetzels JFM, Akiva A, van der Vlag J, Kramann R, Schreuder MF, Smeets B. Human pluripotent stem cell-derived kidney organoids for personalized congenital and idiopathic nephrotic syndrome modeling. Development 2022; 149:275031. [PMID: 35417019 PMCID: PMC9148570 DOI: 10.1242/dev.200198] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 03/28/2022] [Indexed: 12/21/2022]
Abstract
Nephrotic syndrome (NS) is characterized by severe proteinuria as a consequence of kidney glomerular injury due to podocyte damage. In vitro models mimicking in vivo podocyte characteristics are a prerequisite to resolve NS pathogenesis. The detailed characterization of organoid podocytes resulting from a hybrid culture protocol showed a podocyte population that resembles adult podocytes and was superior compared with 2D counterparts, based on single-cell RNA sequencing, super-resolution imaging and electron microscopy. In this study, these next-generation podocytes in kidney organoids enabled personalized idiopathic nephrotic syndrome modeling, as shown by activated slit diaphragm signaling and podocyte injury following protamine sulfate, puromycin aminonucleoside treatment and exposure to NS plasma containing pathogenic permeability factors. Organoids cultured from cells of a patient with heterozygous NPHS2 mutations showed poor NPHS2 expression and aberrant NPHS1 localization, which was reversible after genetic correction. Repaired organoids displayed increased VEGFA pathway activity and transcription factor activity known to be essential for podocyte physiology, as shown by RNA sequencing. This study shows that organoids are the preferred model of choice to study idiopathic and congenital podocytopathies. Summary: Kidney organoid podocytes generated from human pluripotent stem cells using a hybrid differentiation protocol allow podocyte pathophysiology modeling that leads to congenital as well as idiopathic nephrotic syndrome in patients.
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Affiliation(s)
- Jitske Jansen
- Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, The Netherlands.,Department of Pediatric Nephrology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Amalia Children's Hospital, PO Box 9101, 6500 HB Nijmegen, The Netherlands.,Division of Nephrology and Clinical Immunology, Institute of Experimental Medicine and Systems Biology, Medical Faculty RWTH Aachen University, Pauwelsstrasse 30, 52074 Aachen, Germany
| | - Bartholomeus T van den Berge
- Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, The Netherlands.,Department of Nephrology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Martijn van den Broek
- Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, The Netherlands.,Department of Pediatric Nephrology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Amalia Children's Hospital, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Rutger J Maas
- Department of Nephrology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Deniz Daviran
- Department of Biochemistry, Electron Microscopy Center, Radboudumc Technology Center Microscopy, Radboud Institute of Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein 29, 6525 GA Nijmegen, The Netherlands
| | - Brigith Willemsen
- Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Rona Roverts
- Department of Biochemistry, Electron Microscopy Center, Radboudumc Technology Center Microscopy, Radboud Institute of Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein 29, 6525 GA Nijmegen, The Netherlands
| | - Marit van der Kruit
- Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Christoph Kuppe
- Division of Nephrology and Clinical Immunology, Institute of Experimental Medicine and Systems Biology, Medical Faculty RWTH Aachen University, Pauwelsstrasse 30, 52074 Aachen, Germany.,Division of Nephrology and Clinical Immunology, RWTH Aachen University, Aachen 52062, Germany
| | - Katharina C Reimer
- Division of Nephrology and Clinical Immunology, Institute of Experimental Medicine and Systems Biology, Medical Faculty RWTH Aachen University, Pauwelsstrasse 30, 52074 Aachen, Germany.,Division of Nephrology and Clinical Immunology, RWTH Aachen University, Aachen 52062, Germany.,Institute for Biomedical Technologies, Department of Cell Biology, RWTH Aachen University, Aachen 52062, Germany
| | - Gianluca Di Giovanni
- Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, The Netherlands.,Department of Pediatric Nephrology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Amalia Children's Hospital, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Fieke Mooren
- Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Quincy Nlandu
- Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Helmer Mudde
- Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Roy Wetzels
- Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Dirk den Braanker
- Department of Nephrology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Naomi Parr
- Department of Nephrology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - James S Nagai
- Institute for Computational Genomics, University Hospital RWTH Aachen, Achen 52062, Germany.,Joint Research Center for Computational Biomedicine, RWTH Aachen University Hospital, Aachen 52062, Germany
| | | | - Ivan G Costa
- Institute for Computational Genomics, University Hospital RWTH Aachen, Achen 52062, Germany.,Joint Research Center for Computational Biomedicine, RWTH Aachen University Hospital, Aachen 52062, Germany
| | - Eric Steenbergen
- Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Tom Nijenhuis
- Department of Nephrology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Henry Dijkman
- Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Nicole Endlich
- NIPOKA, 17489 Greifswald, Germany.,Department of Anatomy and Cell Biology, University Medicine Greifswald, 17489 Greifswald, Germany
| | - Nicole C A J van de Kar
- Department of Pediatric Nephrology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Amalia Children's Hospital, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Rebekka K Schneider
- Institute for Biomedical Technologies, Department of Cell Biology, RWTH Aachen University, Aachen 52062, Germany.,Department of Developmental Biology, Erasmus Medical Center, Rotterdam 3015 GD, The Netherlands.,Oncode Institute, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Jack F M Wetzels
- Department of Nephrology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Anat Akiva
- Department of Biochemistry, Electron Microscopy Center, Radboudumc Technology Center Microscopy, Radboud Institute of Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein 29, 6525 GA Nijmegen, The Netherlands
| | - Johan van der Vlag
- Department of Nephrology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Rafael Kramann
- Division of Nephrology and Clinical Immunology, Institute of Experimental Medicine and Systems Biology, Medical Faculty RWTH Aachen University, Pauwelsstrasse 30, 52074 Aachen, Germany.,Division of Nephrology and Clinical Immunology, RWTH Aachen University, Aachen 52062, Germany.,Department of Internal Medicine, Nephrology and Transplantation, Erasmus Medical Center, Rotterdam 3015 GD, The Netherlands
| | - Michiel F Schreuder
- Department of Pediatric Nephrology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Amalia Children's Hospital, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Bart Smeets
- Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, The Netherlands
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26
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NUP133 Controls Nuclear Pore Assembly, Transcriptome Composition, and Cytoskeleton Regulation in Podocytes. Cells 2022; 11:cells11081259. [PMID: 35455939 PMCID: PMC9025798 DOI: 10.3390/cells11081259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 04/04/2022] [Accepted: 04/05/2022] [Indexed: 02/04/2023] Open
Abstract
Steroid-resistant nephrotic syndrome (SRNS) frequently leads to end-stage renal disease, ultimately requiring kidney replacement therapies. SRNS is often caused by hereditary monogenic mutations, specifically affecting specialized epithelial cells (podocytes) of the glomerular filtration barrier. Mutations in several components of the nuclear pore complex, including NUP133 and NUP107, have been recently identified to cause hereditary SRNS. However, underlying pathomechanisms, eliciting podocyte-specific manifestations of these nucleoporopathies, remained largely elusive. Here, we generated an in vitro model of NUP133-linked nucleoporopathies using CRISPR/Cas9-mediated genome editing in human podocytes. Transcriptome, nuclear pore assembly, and cytoskeleton regulation of NUP133 loss-of-function, mutant, and wild-type podocytes were analyzed. Loss of NUP133 translated into a disruption of the nuclear pore, alterations of the podocyte-specific transcriptome, and impaired cellular protrusion generation. Surprisingly, comparative analysis of the described SRNS-related NUP133 mutations revealed only mild defects. Am impaired protein interaction in the Y-complex and decrease of NUP133 protein levels might be the primary and unifying consequence of mutant variants, leading to a partial loss-of-function phenotype and disease manifestation in susceptible cell types, such as podocytes.
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27
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Rogg M, Maier JI, Van Wymersch C, Helmstädter M, Sammarco A, Lindenmeyer M, Zareba P, Montanez E, Walz G, Werner M, Endlich N, Benzing T, Huber TB, Schell C. α-Parvin Defines a Specific Integrin Adhesome to Maintain the Glomerular Filtration Barrier. J Am Soc Nephrol 2022; 33:786-808. [PMID: 35260418 PMCID: PMC8970443 DOI: 10.1681/asn.2021101319] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 01/17/2022] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND The cell-matrix adhesion between podocytes and the glomerular basement membrane is essential for the integrity of the kidney's filtration barrier. Despite increasing knowledge about the complexity of integrin adhesion complexes, an understanding of the regulation of these protein complexes in glomerular disease remains elusive. METHODS We mapped the in vivo composition of the podocyte integrin adhesome. In addition, we analyzed conditional knockout mice targeting a gene (Parva) that encodes an actin-binding protein (α-parvin), and murine disease models. To evaluate podocytes in vivo, we used super-resolution microscopy, electron microscopy, multiplex immunofluorescence microscopy, and RNA sequencing. We performed functional analysis of CRISPR/Cas9-generated PARVA single knockout podocytes and PARVA and PARVB double knockout podocytes in three- and two-dimensional cultures using specific extracellular matrix ligands and micropatterns. RESULTS We found that PARVA is essential to prevent podocyte foot process effacement, detachment from the glomerular basement membrane, and the development of FSGS. Through the use of in vitro and in vivo models, we identified an inherent PARVB-dependent compensatory module at podocyte integrin adhesion complexes, sustaining efficient mechanical linkage at the filtration barrier. Sequential genetic deletion of PARVA and PARVB induces a switch in structure and composition of integrin adhesion complexes. This redistribution of these complexes translates into a loss of the ventral actin cytoskeleton, decreased adhesion capacity, impaired mechanical resistance, and dysfunctional extracellular matrix assembly. CONCLUSIONS The findings reveal adaptive mechanisms of podocyte integrin adhesion complexes, providing a conceptual framework for therapeutic strategies to prevent podocyte detachment in glomerular disease.
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Affiliation(s)
- Manuel Rogg
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany
| | - Jasmin I Maier
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany
| | - Clara Van Wymersch
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany
| | - Martin Helmstädter
- Department of Medicine IV, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany
| | - Alena Sammarco
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany
| | - Maja Lindenmeyer
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Paulina Zareba
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany
| | - Eloi Montanez
- Department of Physiological Sciences, Faculty of Medicine, University of Barcelona and Health Sciences and Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain
| | - Gerd Walz
- Department of Medicine IV, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany
| | - Martin Werner
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany
| | - Nicole Endlich
- Department of Anatomy and Cell Biology, University Medicine Greifswald, Greifswald, Germany
| | - Thomas Benzing
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Tobias B Huber
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christoph Schell
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany .,Freiburg Institute for Advanced Studies (FRIAS), University of Freiburg, Freiburg, Germany
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28
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Tuffin J, Chesor M, Kuzmuk V, Johnson T, Satchell SC, Welsh GI, Saleem MA. GlomSpheres as a 3D co-culture spheroid model of the kidney glomerulus for rapid drug-screening. Commun Biol 2021; 4:1351. [PMID: 34857869 PMCID: PMC8640035 DOI: 10.1038/s42003-021-02868-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 10/28/2021] [Indexed: 01/28/2023] Open
Abstract
The glomerulus is the filtration unit of the kidney. Injury to any component of this specialised structure leads to impaired filtration and eventually fibrosis and chronic kidney disease. Current two and three dimensional (2D and 3D) models that attempt to recreate structure and interplay between glomerular cells are imperfect. Most 2D models are simplistic and unrepresentative, and 3D organoid approaches are currently difficult to reproduce at scale and do not fit well with current industrial drug-screening approaches. Here we report a rapidly generated and highly reproducible 3D co-culture spheroid model (GlomSpheres), better demonstrating the specialised physical and molecular structure of a glomerulus. Co-cultured using a magnetic spheroid formation approach, conditionally immortalised (CI) human podocytes and glomerular endothelial cells (GEnCs) deposited mature, organized isoforms of collagen IV and Laminin. We demonstrate a dramatic upregulation of key podocyte (podocin, nephrin and podocalyxin) and GEnC (pecam-1) markers. Electron microscopy revealed podocyte foot process interdigitation and endothelial vessel formation. Incubation with pro-fibrotic agents (TGF-β1, Adriamycin) induced extracellular matrix (ECM) dysregulation and podocyte loss, which were attenuated by the anti-fibrotic agent Nintedanib. Incubation with plasma from patients with kidney disease induced acute podocyte loss and ECM dysregulation relative to patient matched remission plasma, and Nintedanib reduced podocyte loss. Finally, we developed a rapid imaging approach to demonstrate the model's usefulness in higher throughput pharmaceutical screening. GlomSpheres therefore represent a robust, scalable, replacement for 2D in vitro glomerular disease models.
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Affiliation(s)
- Jack Tuffin
- Bristol Renal, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, BS1 3NY, UK.
| | - Musleeha Chesor
- Bristol Renal, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, BS1 3NY, UK.,Faculty of Medicine, Princess of Naradhiwas University, Narathiwat, Thailand
| | - Valeryia Kuzmuk
- Bristol Renal, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, BS1 3NY, UK
| | | | - Simon C Satchell
- Bristol Renal, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, BS1 3NY, UK
| | - Gavin I Welsh
- Bristol Renal, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, BS1 3NY, UK
| | - Moin A Saleem
- Bristol Renal, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, BS1 3NY, UK
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29
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Caza TN, Al-Rabadi LF, Beck LH. How Times Have Changed! A Cornucopia of Antigens for Membranous Nephropathy. Front Immunol 2021; 12:800242. [PMID: 34899763 PMCID: PMC8662735 DOI: 10.3389/fimmu.2021.800242] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 11/09/2021] [Indexed: 11/13/2022] Open
Abstract
The identification of the major target antigen phospholipase A2 receptor (PLA2R) in the majority of primary (idiopathic) cases of membranous nephropathy (MN) has been followed by the rapid identification of numerous minor antigens that appear to define phenotypically distinct forms of disease. This article serves to review all the known antigens that have been shown to localize to subepithelial deposits in MN, as well as the distinctive characteristics associated with each subtype of MN. We will also shed light on the novel proteomic approaches that have allowed identification of the most recent antigens. The paradigm of an antigen normally expressed on the podocyte cell surface leading to in-situ immune complex formation, complement activation, and subsequent podocyte injury will be discussed and challenged in light of the current repertoire of multiple MN antigens. Since disease phenotypes associated with each individual target antigens can often blur the distinction between primary and secondary disease, we encourage the use of antigen-based classification of membranous nephropathy.
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Affiliation(s)
| | - Laith F. Al-Rabadi
- Department of Internal Medicine (Nephrology & Hypertension), University of Utah, Salt Lake City, UT, United States
| | - Laurence H. Beck
- Department of Medicine (Nephrology), Boston University School of Medicine and Boston Medical Center, Boston, MA, United States
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Liu W, Huang G, Rui H, Geng J, Hu H, Huang Y, Huo G, Liu B, Xu A. Course monitoring of membranous nephropathy: Both autoantibodies and podocytes require multidimensional attention. Autoimmun Rev 2021; 21:102976. [PMID: 34757091 DOI: 10.1016/j.autrev.2021.102976] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 10/18/2021] [Accepted: 10/24/2021] [Indexed: 01/15/2023]
Abstract
A variety of podocyte antigens have been identified in human membranous nephropathy (MN), which is divided into various antigen-dominated subtypes, confirming the concept that MN is the common pattern of glomerular injury in multiple autoimmune responses. The detection of autoantibodies has been widely used, which promoted the clinical practice of MN toward personalized precision medicine. However, given the potential risks of immunosuppressive therapy, more autoantibodies and biomarkers need to be identified to predict the prognosis and therapeutic response of MN more accurately. In this review, we attempted to summarize the autoantigens/autoantibodies and autoimmune mechanisms that can predict disease states based on the current understanding of MN pathogenesis, especially the podocyte injury manifestations. In conclusion, both the autoimmune response and podocyte injury require multidimensional attention in the disease course of MN.
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Affiliation(s)
- Wenbin Liu
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Guangrui Huang
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Hongliang Rui
- Beijing Hospital of Traditional Chinese Medicine, Capital Medical University, Beijing, China
| | - Jie Geng
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Haikun Hu
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Yujiao Huang
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Guiyang Huo
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Baoli Liu
- Beijing Hospital of Traditional Chinese Medicine, Capital Medical University, Beijing, China.
| | - Anlong Xu
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China.
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Hatje FA, Wedekind U, Sachs W, Loreth D, Reichelt J, Demir F, Kosub C, Heintz L, Tomas NM, Huber TB, Skuza S, Sachs M, Zielinski S, Rinschen MM, Meyer-Schwesinger C. Tripartite Separation of Glomerular Cell Types and Proteomes from Reporter-Free Mice. J Am Soc Nephrol 2021; 32:2175-2193. [PMID: 34074698 PMCID: PMC8729851 DOI: 10.1681/asn.2020091346] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Accepted: 04/09/2021] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND The glomerulus comprises podocytes, mesangial cells, and endothelial cells, which jointly determine glomerular filtration. Understanding this intricate functional unit beyond the transcriptome requires bulk isolation of these cell types for biochemical investigations. We developed a globally applicable tripartite isolation method for murine mesangial and endothelial cells and podocytes (timMEP). METHODS We separated glomerular cell types from wild-type or mT/mG mice via a novel FACS approach, and validated their purity. Cell type proteomes were compared between strains, ages, and sex. We applied timMEP to the podocyte-targeting, immunologic, THSD7A-associated, model of membranous nephropathy. RESULTS timMEP enabled protein-biochemical analyses of podocytes, mesangial cells, and endothelial cells derived from reporter-free mice, and allowed for the characterization of podocyte, endothelial, and mesangial proteomes of individual mice. We identified marker proteins for mesangial and endothelial proteins, and outlined protein-based, potential communication networks and phosphorylation patterns. The analysis detected cell type-specific proteome differences between mouse strains and alterations depending on sex, age, and transgene. After exposure to anti-THSD7A antibodies, timMEP resolved a fine-tuned initial stress response, chiefly in podocytes, that could not be detected by bulk glomerular analyses. The combination of proteomics with super-resolution imaging revealed a specific loss of slit diaphragm, but not of other foot process proteins, unraveling a protein-based mechanism of podocyte injury in this animal model. CONCLUSION timMEP enables glomerular cell type-resolved investigations at the transcriptional and protein-biochemical level in health and disease, while avoiding reporter-based artifacts, paving the way toward the comprehensive and systematic characterization of glomerular cell biology.
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Affiliation(s)
- Favian A. Hatje
- Institute of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Uta Wedekind
- Institute of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Wiebke Sachs
- Institute of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Desiree Loreth
- Institute of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Julia Reichelt
- Institute of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Fatih Demir
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Christopher Kosub
- Institute of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Lukas Heintz
- Institute of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Nicola M. Tomas
- III Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Tobias B. Huber
- III Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Sinah Skuza
- Institute of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Marlies Sachs
- Institute of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Stephanie Zielinski
- Institute of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Markus M. Rinschen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
- III Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Department II of Internal Medicine, Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Catherine Meyer-Schwesinger
- Institute of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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32
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Höhfeld J, Benzing T, Bloch W, Fürst DO, Gehlert S, Hesse M, Hoffmann B, Hoppe T, Huesgen PF, Köhn M, Kolanus W, Merkel R, Niessen CM, Pokrzywa W, Rinschen MM, Wachten D, Warscheid B. Maintaining proteostasis under mechanical stress. EMBO Rep 2021; 22:e52507. [PMID: 34309183 PMCID: PMC8339670 DOI: 10.15252/embr.202152507] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 06/28/2021] [Accepted: 07/01/2021] [Indexed: 12/11/2022] Open
Abstract
Cell survival, tissue integrity and organismal health depend on the ability to maintain functional protein networks even under conditions that threaten protein integrity. Protection against such stress conditions involves the adaptation of folding and degradation machineries, which help to preserve the protein network by facilitating the refolding or disposal of damaged proteins. In multicellular organisms, cells are permanently exposed to stress resulting from mechanical forces. Yet, for long time mechanical stress was not recognized as a primary stressor that perturbs protein structure and threatens proteome integrity. The identification and characterization of protein folding and degradation systems, which handle force-unfolded proteins, marks a turning point in this regard. It has become apparent that mechanical stress protection operates during cell differentiation, adhesion and migration and is essential for maintaining tissues such as skeletal muscle, heart and kidney as well as the immune system. Here, we provide an overview of recent advances in our understanding of mechanical stress protection.
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Affiliation(s)
- Jörg Höhfeld
- Institute for Cell BiologyRheinische Friedrich‐Wilhelms University BonnBonnGermany
| | - Thomas Benzing
- Department II of Internal Medicine and Center for Molecular Medicine Cologne (CMMC)University of CologneCologneGermany
| | - Wilhelm Bloch
- Institute of Cardiovascular Research and Sports MedicineGerman Sport UniversityCologneGermany
| | - Dieter O Fürst
- Institute for Cell BiologyRheinische Friedrich‐Wilhelms University BonnBonnGermany
| | - Sebastian Gehlert
- Institute of Cardiovascular Research and Sports MedicineGerman Sport UniversityCologneGermany
- Department for the Biosciences of SportsInstitute of Sports ScienceUniversity of HildesheimHildesheimGermany
| | - Michael Hesse
- Institute of Physiology I, Life & Brain CenterMedical FacultyRheinische Friedrich‐Wilhelms UniversityBonnGermany
| | - Bernd Hoffmann
- Institute of Biological Information Processing, IBI‐2: MechanobiologyForschungszentrum JülichJülichGermany
| | - Thorsten Hoppe
- Institute for GeneticsCologne Excellence Cluster on Cellular Stress Responses in Aging‐Associated Diseases (CECAD) and CMMCUniversity of CologneCologneGermany
| | - Pitter F Huesgen
- Central Institute for Engineering, Electronics and Analytics, ZEA3Forschungszentrum JülichJülichGermany
- CECADUniversity of CologneCologneGermany
| | - Maja Köhn
- Institute of Biology IIIFaculty of Biology, and Signalling Research Centres BIOSS and CIBSSAlbert‐Ludwigs‐University FreiburgFreiburgGermany
| | - Waldemar Kolanus
- LIMES‐InstituteRheinische Friedrich‐Wilhelms University BonnBonnGermany
| | - Rudolf Merkel
- Institute of Biological Information Processing, IBI‐2: MechanobiologyForschungszentrum JülichJülichGermany
| | - Carien M Niessen
- Department of Dermatology and CECADUniversity of CologneCologneGermany
| | | | - Markus M Rinschen
- Department of Biomedicine and Aarhus Institute of Advanced StudiesAarhus UniversityAarhusDenmark
- Department of MedicineUniversity Medical Center Hamburg‐EppendorfHamburgGermany
| | - Dagmar Wachten
- Institute of Innate ImmunityUniversity Hospital BonnBonnGermany
| | - Bettina Warscheid
- Institute of Biology IIFaculty of Biology, and Signalling Research Centres BIOSS and CIBSSAlbert‐Ludwigs‐University FreiburgFreiburgGermany
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Xu Y, Guo C, Pan W, Zhao C, Ding Y, Xie X, Wei Z, Sun Y, Yu C. Nephrotic-syndrome-associated mutation of KANK2 induces pathologic binding competition with physiological interactor KIF21A. J Biol Chem 2021; 297:100958. [PMID: 34274317 PMCID: PMC8368038 DOI: 10.1016/j.jbc.2021.100958] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 05/17/2021] [Accepted: 07/09/2021] [Indexed: 10/25/2022] Open
Abstract
Nephrotic syndrome (NS) is a common kidney disorder caused by dysfunction of the glomerular filtration barrier. Some genetic mutations identified in NS patients cause amino acid substitutions of kidney ankyrin repeat-containing (KANK) proteins, which are scaffold proteins that regulate actin polymerization, microtubule targeting, and cell adhesion via binding to various molecules, including the kinesin motor protein KIF21A. However, the mechanisms by which these mutations lead to NS are unclear. Here, we unexpectedly found that the eukaryotic translation initiation factor 4A1 (eIF4A1) interacts with an NS-associated KANK2 mutant (S684F) but not the wild-type protein. Biochemical and structural analyses revealed that the pathological mutation induces abnormal binding of eIF4A1 to KANK2 at the physiological KIF21A-binding site. Competitive binding assays further indicated that eIF4A1 can compete with KIF21A to interact with the S684F mutant of KANK2. In cultured mouse podocytes, this S684F mutant interfered with the KANK2/KIF21A interaction by binding to eIF4A1, and failed to rescue the focal adhesion or cell adhesion that had been reduced or morphologically changed by KANK2 knockout. These structural, biochemical, and cellular results not only provide mechanistic explanations for the podocyte defects caused by the S684F mutation, but also show how a gain-of-binding mutation can lead to a loss-of-function effect.
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Affiliation(s)
- Yuqun Xu
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Chen Guo
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Wenfei Pan
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Chan Zhao
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Yanyan Ding
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Xingqiao Xie
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China; Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Zhiyi Wei
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China; Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, Guangdong, China; Brain Research Center, Southern University of Science and Technology, Shenzhen, Guangdong, China.
| | - Ying Sun
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China; Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, and Shenzhen Key Laboratory of Cell Microenvironment, Department of Biology, Southern Univeristy of Science and Technology, Shenzhen, Guangdong, China.
| | - Cong Yu
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China; Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, Guangdong, China; Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, and Shenzhen Key Laboratory of Cell Microenvironment, Department of Biology, Southern Univeristy of Science and Technology, Shenzhen, Guangdong, China.
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Caza TN, Hassen SI, Kuperman M, Sharma SG, Dvanajscak Z, Arthur J, Edmondson R, Storey A, Herzog C, Kenan DJ, Larsen CP. Neural cell adhesion molecule 1 is a novel autoantigen in membranous lupus nephritis. Kidney Int 2021; 100:171-181. [PMID: 33045259 PMCID: PMC8032825 DOI: 10.1016/j.kint.2020.09.016] [Citation(s) in RCA: 79] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 08/28/2020] [Accepted: 09/03/2020] [Indexed: 12/15/2022]
Abstract
Membranous lupus nephritis is a frequent cause of nephrotic syndrome in patients with systemic lupus erythematosus. It has been shown in phospholipase A2 receptor positive membranous nephropathy that known antibodies can be detected within sera, determination of the target autoantigen can have diagnostic significance, inform prognosis, and enable non-invasive monitoring of disease activity. Here we utilized mass spectrometry for antigen discovery in laser captured microdissected glomeruli from formalin-fixed paraffin embedded tissue and tissue protein G immunoprecipitation studies to interrogate immune complexes from frozen kidney biopsy tissue. We identified neural cell adhesion molecule 1 (NCAM1) to be a target antigen in some cases of membranous lupus nephritis and within rare cases of primary membranous nephropathy. The prevalence of NCAM1 association was 6.6% of cases of membranous lupus nephritis and in 2.0% of primary membranous nephropathy cases. NCAM1 was found to colocalize with IgG within glomerular immune deposits by confocal microscopy. Additionally, serum from patients with NCAM1-associated membranous nephropathy showed reactivity to NCAM1 recombinant protein on Western blotting and by indirect immunofluorescence assay, demonstrating the presence of circulating antibodies. Thus, we propose that NCAM1 is a target autoantigen in a subset of patients with membranous lupus nephritis. Future studies are needed to determine whether anti-NCAM1 antibody levels correlate with disease activity or response to therapy.
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Affiliation(s)
| | | | | | | | | | - John Arthur
- University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Rick Edmondson
- University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Aaron Storey
- University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Christian Herzog
- University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
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35
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Al-Rabadi LF, Caza T, Trivin-Avillach C, Rodan AR, Andeen N, Hayashi N, Williams B, Revelo MP, Clayton F, Abraham J, Lin E, Liou W, Zou CJ, Ramkumar N, Cummins T, Wilkey DW, Kawalit I, Herzog C, Storey A, Edmondson R, Sjoberg R, Yang T, Chien J, Merchant M, Arthur J, Klein J, Larsen C, Beck LH. Serine Protease HTRA1 as a Novel Target Antigen in Primary Membranous Nephropathy. J Am Soc Nephrol 2021; 32:1666-1681. [PMID: 33952630 PMCID: PMC8425645 DOI: 10.1681/asn.2020101395] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 02/21/2021] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Identification of target antigens PLA2R, THSD7A, NELL1, or Semaphorin-3B can explain the majority of cases of primary membranous nephropathy (MN). However, target antigens remain unidentified in 15%-20% of patients. METHODS A multipronged approach, using traditional and modern technologies, converged on a novel target antigen, and capitalized on the temporal variation in autoantibody titer for biomarker discovery. Immunoblotting of human glomerular proteins followed by differential immunoprecipitation and mass spectrometric analysis was complemented by laser-capture microdissection followed by mass spectrometry, elution of immune complexes from renal biopsy specimen tissue, and autoimmune profiling on a protein fragment microarray. RESULTS These approaches identified serine protease HTRA1 as a novel podocyte antigen in a subset of patients with primary MN. Sera from two patients reacted by immunoblotting with a 51-kD protein within glomerular extract and with recombinant human HTRA1, under reducing and nonreducing conditions. Longitudinal serum samples from these patients seemed to correlate with clinical disease activity. As in PLA2R- and THSD7A- associated MN, anti-HTRA1 antibodies were predominantly IgG4, suggesting a primary etiology. Analysis of sera collected during active disease versus remission on protein fragment microarrays detected significantly higher titers of anti-HTRA1 antibody in active disease. HTRA1 was specifically detected within immune deposits of HTRA1-associated MN in 14 patients identified among three cohorts. Screening of 118 "quadruple-negative" (PLA2R-, THSD7A-, NELL1-, EXT2-negative) patients in a large repository of MN biopsy specimens revealed a prevalence of 4.2%. CONCLUSIONS Conventional and more modern techniques converged to identify serine protease HTRA1 as a target antigen in MN.
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Affiliation(s)
- Laith Farah Al-Rabadi
- Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah Health, Salt Lake City, Utah
| | | | - Claire Trivin-Avillach
- Section of Nephrology, Department of Medicine, Boston Medical Center and Boston University School of Medicine, Boston, Massachusetts
| | - Aylin R. Rodan
- Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah Health, Salt Lake City, Utah,Molecular Medicine Program, University of Utah Health, Salt Lake City, Utah,Department of Human Genetics, University of Utah Health, Salt Lake City, Utah,Medical Service, Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah
| | - Nicole Andeen
- Department of Pathology, Oregon Health and Science University, Portland, Oregon
| | - Norifumi Hayashi
- Section of Nephrology, Department of Medicine, Boston Medical Center and Boston University School of Medicine, Boston, Massachusetts,Kanazawa Medical University, Ishikawa, Japan
| | - Brandi Williams
- Moran Eye Center, University of Utah Health, Salt Lake City, Utah
| | - Monica P. Revelo
- Department of Pathology, University of Utah Health, Salt Lake City, Utah
| | - Fred Clayton
- Department of Pathology, University of Utah Health, Salt Lake City, Utah
| | - Jo Abraham
- Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah Health, Salt Lake City, Utah
| | - Edwin Lin
- Department of Human Genetics, University of Utah Health, Salt Lake City, Utah
| | - Willisa Liou
- Department of Pathology, University of Utah Health, Salt Lake City, Utah
| | - Chang-Jiang Zou
- Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah Health, Salt Lake City, Utah
| | - Nirupama Ramkumar
- Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah Health, Salt Lake City, Utah
| | - Tim Cummins
- Clinical Proteomics Laboratory, Division of Nephrology and Hypertension, Department of Medicine, University of Louisville School of Medicine, Louisville, Kentucky
| | - Daniel W. Wilkey
- Clinical Proteomics Laboratory, Division of Nephrology and Hypertension, Department of Medicine, University of Louisville School of Medicine, Louisville, Kentucky
| | - Issa Kawalit
- International Renal Care Association, Amman, Jordan
| | - Christian Herzog
- Nephrology Division, Internal Medicine Department, University of Arkansas for Medical Science, Little Rock, Arkansas
| | - Aaron Storey
- Nephrology Division, Internal Medicine Department, University of Arkansas for Medical Science, Little Rock, Arkansas
| | - Rick Edmondson
- Nephrology Division, Internal Medicine Department, University of Arkansas for Medical Science, Little Rock, Arkansas
| | - Ronald Sjoberg
- Division of Affinity Proteomics, Department of Protein Science, KTH Royal Institute of Technology, SciLifeLab, Stockholm, Sweden
| | - Tianxin Yang
- Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah Health, Salt Lake City, Utah,Medical Service, Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah
| | - Jeremy Chien
- Department of Biochemistry and Molecular Medicine, University of California Davis Health, Davis, California
| | - Michael Merchant
- Clinical Proteomics Laboratory, Division of Nephrology and Hypertension, Department of Medicine, University of Louisville School of Medicine, Louisville, Kentucky
| | - John Arthur
- Nephrology Division, Internal Medicine Department, University of Arkansas for Medical Science, Little Rock, Arkansas
| | - Jon Klein
- Clinical Proteomics Laboratory, Division of Nephrology and Hypertension, Department of Medicine, University of Louisville School of Medicine, Louisville, Kentucky,Robley Rex Veterans Administration Medical Center, Louisville, Kentucky
| | | | - Laurence H. Beck
- Section of Nephrology, Department of Medicine, Boston Medical Center and Boston University School of Medicine, Boston, Massachusetts
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Mysh M, Poulton JS. The Basolateral Polarity Module Promotes Slit Diaphragm Formation in Drosophila Nephrocytes, a Model of Vertebrate Podocytes. J Am Soc Nephrol 2021; 32:1409-1424. [PMID: 33795424 PMCID: PMC8259641 DOI: 10.1681/asn.2020071050] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 02/12/2021] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Podocyte slit diaphragms (SDs) are intercellular junctions that function as size-selective filters, excluding most proteins from urine. Abnormalities in SDs cause proteinuria and nephrotic syndrome. Podocytes exhibit apicobasal polarity, which can affect fundamental aspects of cell biology, including morphology, intercellular junction formation, and asymmetric protein distribution along the plasma membrane. Apical polarity protein mutations cause nephrotic syndrome, and data suggest apical polarity proteins regulate SD formation. However, there is no evidence that basolateral polarity proteins regulate SDs. Thus, the role of apicobasal polarity in podocytes remains unclear. METHODS Genetic manipulations and transgenic reporters determined the effects of disrupting apicobasal polarity proteins in Drosophila nephrocytes, which have SDs similar to those of mammalian podocytes. Confocal and electron microscopy were used to characterize SD integrity after loss of basolateral polarity proteins, and genetic-interaction studies illuminated relationships among apicobasal polarity proteins. RESULTS The study identified four novel regulators of nephrocyte SDs: Dlg, Lgl, Scrib, and Par-1. These proteins comprise the basolateral polarity module and its effector kinase. The data suggest these proteins work together, with apical polarity proteins, to regulate SDs by promoting normal endocytosis and trafficking of SD proteins. CONCLUSIONS Given the recognized importance of apical polarity proteins and SD protein trafficking in podocytopathies, the findings connecting basolateral polarity proteins to these processes significantly advance our understanding of SD regulation.
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Affiliation(s)
- Michael Mysh
- Department of Biology, UNC Kidney Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - John S. Poulton
- Division of Nephrology and Hypertension, Department of Medicine, UNC Kidney Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
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Lindenmeyer MT, Alakwaa F, Rose M, Kretzler M. Perspectives in systems nephrology. Cell Tissue Res 2021; 385:475-488. [PMID: 34027630 PMCID: PMC8523456 DOI: 10.1007/s00441-021-03470-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 04/28/2021] [Indexed: 12/19/2022]
Abstract
Chronic kidney diseases (CKD) are a major health problem affecting approximately 10% of the world’s population and posing increasing challenges to the healthcare system. While CKD encompasses a broad spectrum of pathological processes and diverse etiologies, the classification of kidney disease is currently based on clinical findings or histopathological categorizations. This descriptive classification is agnostic towards the underlying disease mechanisms and has limited progress towards the ability to predict disease prognosis and treatment responses. To gain better insight into the complex and heterogeneous disease pathophysiology of CKD, a systems biology approach can be transformative. Rather than examining one factor or pathway at a time, as in the reductionist approach, with this strategy a broad spectrum of information is integrated, including comprehensive multi-omics data, clinical phenotypic information, and clinicopathological parameters. In recent years, rapid advances in mathematical, statistical, computational, and artificial intelligence methods enable the mapping of diverse big data sets. This holistic approach aims to identify the molecular basis of CKD subtypes as well as individual determinants of disease manifestation in a given patient. The emerging mechanism-based patient stratification and disease classification will lead to improved prognostic and predictive diagnostics and the discovery of novel molecular disease-specific therapies.
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Affiliation(s)
- Maja T Lindenmeyer
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
| | - Fadhl Alakwaa
- Department of Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Michael Rose
- Department of Medicine, University of Michigan, Ann Arbor, MI, USA
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38
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Merscher S, Faul C. DACH1 as a multifaceted and potentially druggable susceptibility factor for kidney disease. J Clin Invest 2021; 131:149043. [PMID: 33998596 PMCID: PMC8121511 DOI: 10.1172/jci149043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Kidney diseases affect more than 15% of adults in the US, yet drug development in the kidney field, when compared with that for other common diseases, has been lagging behind. Modifiers that increase the susceptibility to injury and contribute to the pathogenesis and progression of kidney disease include genetic and environmental factors and epigenetic mechanisms. In this issue of the JCI, Cao et al. and Doke et al. independently report the identification of a susceptibility factor called Dachshund homolog 1 (DACH1). Both groups identify an association of reduced DACH1 expression with kidney disease, using different screening approaches, studying different types of human kidney diseases, and using different experimental models, making the fact that both stumbled over the same protein very compelling. Combined, these studies highlight DACH1 as a key safeguard in the kidney, granting various cell types proper function by modulating several molecular pathways.
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Affiliation(s)
- Sandra Merscher
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami Miller School of Medicine, Miami, Florida, USA
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Christian Faul
- Division of Nephrology, Department of Medicine, The University of Alabama at Birmingham (UAB), Birmingham, Alabama, USA
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Cao A, Li J, Asadi M, Basgen JM, Zhu B, Yi Z, Jiang S, Doke T, El Shamy O, Patel N, Cravedi P, Azeloglu EU, Campbell KN, Menon M, Coca S, Zhang W, Wang H, Zen K, Liu Z, Murphy B, He JC, D’Agati VD, Susztak K, Kaufman L. DACH1 protects podocytes from experimental diabetic injury and modulates PTIP-H3K4Me3 activity. J Clin Invest 2021; 131:141279. [PMID: 33998601 PMCID: PMC8121508 DOI: 10.1172/jci141279] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 03/23/2021] [Indexed: 01/15/2023] Open
Abstract
Dachshund homolog 1 (DACH1), a key cell-fate determinant, regulates transcription by DNA sequence-specific binding. We identified diminished Dach1 expression in a large-scale screen for mutations that convert injury-resistant podocytes into injury-susceptible podocytes. In diabetic kidney disease (DKD) patients, podocyte DACH1 expression levels are diminished, a condition that strongly correlates with poor clinical outcomes. Global Dach1 KO mice manifest renal hypoplasia and die perinatally. Podocyte-specific Dach1 KO mice, however, maintain normal glomerular architecture at baseline, but rapidly exhibit podocyte injury after diabetes onset. Furthermore, podocyte-specific augmentation of DACH1 expression in mice protects from DKD. Combined RNA sequencing and in silico promoter analysis reveal conversely overlapping glomerular transcriptomic signatures between podocyte-specific Dach1 and Pax transactivation-domain interacting protein (Ptip) KO mice, with upregulated genes possessing higher-than-expected numbers of promoter Dach1-binding sites. PTIP, an essential component of the activating histone H3 lysine 4 trimethylation (H3K4Me3) complex, interacts with DACH1 and is recruited by DACH1 to its promoter-binding sites. DACH1-PTIP recruitment represses transcription and reduces promoter H3K4Me3 levels. DACH1 knockdown in podocytes combined with hyperglycemia triggers target gene upregulation and increases promoter H3K4Me3. These findings reveal that in DKD, diminished DACH1 expression enhances podocyte injury vulnerability via epigenetic derepression of its target genes.
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Affiliation(s)
- Aili Cao
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Department of Nephrology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Jianhua Li
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Morad Asadi
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - John M. Basgen
- Life Science Institute, Charles R. Drew University of Medicine and Science, Los Angeles, California, USA
| | - Bingbing Zhu
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Department of Nephrology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Zhengzi Yi
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Song Jiang
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, Jiangsu, China
| | - Tomohito Doke
- Renal Electrolyte and Hypertension Division, Perelman School of Medicine at University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Osama El Shamy
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Niralee Patel
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Paolo Cravedi
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Evren U. Azeloglu
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Kirk N. Campbell
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Madhav Menon
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Steve Coca
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Weijia Zhang
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Hao Wang
- Department of Nephrology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Ke Zen
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, Jiangsu, China
| | - Zhihong Liu
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, Jiangsu, China
| | - Barbara Murphy
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - John C. He
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Vivette D. D’Agati
- Department of Pathology, Columbia University Medical Center, New York, New York, USA
| | - Katalin Susztak
- Renal Electrolyte and Hypertension Division, Perelman School of Medicine at University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Lewis Kaufman
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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40
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Immune-mediated entities of (primary) focal segmental glomerulosclerosis. Cell Tissue Res 2021; 385:423-434. [PMID: 33907872 PMCID: PMC8523460 DOI: 10.1007/s00441-021-03454-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 03/19/2021] [Indexed: 12/21/2022]
Abstract
Focal segmental glomerulosclerosis (FSGS) represents a glomerular scar formation downstream of various different mechanisms leading to podocytopathy and podocyte loss. Recently, significant advances were made in understanding genetic factors, podocyte intrinsic mechanisms, and adaptive mechanisms causing FSGS. However, while most cases of nephrotic FSGS are being treated with immunosuppressants, the underlying immune dysregulation, involved immune cells, and soluble factors are only incompletely understood. Thus, we here summarize the current knowledge of proposed immune effector cells, secreted soluble factors, and podocyte response in immune-mediated (primary) FSGS.
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Abstract
Proteases play a central role in regulating renal pathophysiology and are increasingly evaluated as actionable drug targets. Here, we review the role of proteolytic systems in inflammatory kidney disease. Inflammatory kidney diseases are associated with broad dysregulations of extracellular and intracellular proteolysis. As an example of a proteolytic system, the complement system plays a significant role in glomerular inflammatory kidney disease and is currently under clinical investigation. Based on two glomerular kidney diseases, lupus nephritis, and membranous nephropathy, we portrait two proteolytic pathomechanisms and the role of the complement system. We discuss how profiling proteolytic activity in patient samples could be used to stratify patients for more targeted interventions in inflammatory kidney diseases. We also describe novel comprehensive, quantitative tools to investigate the entirety of proteolytic processes in a tissue sample. Emphasis is placed on mass spectrometric approaches that enable the comprehensive analysis of the complement system, as well as protease activities and regulation in general.
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Okabe M, Yamamoto K, Miyazaki Y, Motojima M, Ohtsuka M, Pastan I, Yokoo T, Matsusaka T. Indirect podocyte injury manifested in a partial podocytectomy mouse model. Am J Physiol Renal Physiol 2021; 320:F922-F933. [PMID: 33719575 DOI: 10.1152/ajprenal.00602.2020] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In progressive glomerular diseases, segmental podocyte injury often expands, leading to global glomerulosclerosis by unclear mechanisms. To study the expansion of podocyte injury, we established a new mosaic mouse model in which a fraction of podocytes express human (h)CD25 and can be injured by the immunotoxin LMB2. hCD25+ and hCD25- podocytes were designed to express tdTomato and enhanced green fluorescent protein (EGFP), respectively, which enabled cell sorting analysis of podocytes. After the injection of LMB2, mosaic mice developed proteinuria and glomerulosclerosis. Not only tdTomato+ podocytes but also EGFP+ podocytes were decreased in number and showed damage, as evidenced by a decrease in nephrin and an increase in desmin at both protein and RNA levels. Transcriptomics analysis found a decrease in the glucocorticoid-induced transcript 1 gene and an increase in the thrombospondin 4, heparin-binding EGF-like growth factor, and transforming growth factor-β genes in EGFP+ podocytes; these genes may be candidate mediators of secondary podocyte damage. Pathway analysis suggested that focal adhesion, integrin-mediated cell adhesion, and focal adhesion-phosphatidylinositol 3-kinase-Akt-mammalian target of rapamycin signaling are involved in secondary podocyte injury. Finally, treatment of mosaic mice with angiotensin II receptor blocker markedly ameliorated secondary podocyte injury. This mosaic podocyte injury model has distinctly demonstrated that damaged podocytes cause secondary podocyte damage, which may be a promising therapeutic target in progressive kidney diseases.NEW & NOTEWORTHY This novel mosaic model has demonstrated that when a fraction of podocytes is injured, other podocytes are subjected to secondary injury. This spreading of injury may occur ubiquitously irrespective of the primary cause of podocyte injury, leading to end-stage renal failure. Understanding the molecular mechanism of secondary podocyte injury and its prevention is important for the treatment of progressive kidney diseases. This model will be a powerful tool for studying the indirect podocyte injury.
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Affiliation(s)
- Masahiro Okabe
- Division of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan.,Department of Basic Medicine, Tokai University School of Medicine, Isehara, Japan
| | - Kazuyoshi Yamamoto
- Division of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan.,Department of Basic Medicine, Tokai University School of Medicine, Isehara, Japan
| | - Yoichi Miyazaki
- Division of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan
| | - Masaru Motojima
- Department of Clinical Pharmacology, Tokai University School of Medicine, Isehara, Japan
| | - Masato Ohtsuka
- Department of Basic Medicine, Tokai University School of Medicine, Isehara, Japan.,Institute of Medical Science, Tokai University School of Medicine, Isehara, Japan
| | - Ira Pastan
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
| | - Takashi Yokoo
- Division of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan
| | - Taiji Matsusaka
- Department of Basic Medicine, Tokai University School of Medicine, Isehara, Japan.,Institute of Medical Science, Tokai University School of Medicine, Isehara, Japan
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Rogg M, Maier JI, Dotzauer R, Artelt N, Kretz O, Helmstädter M, Abed A, Sammarco A, Sigle A, Sellung D, Dinse P, Reiche K, Yasuda-Yamahara M, Biniossek ML, Walz G, Werner M, Endlich N, Schilling O, Huber TB, Schell C. SRGAP1 Controls Small Rho GTPases To Regulate Podocyte Foot Process Maintenance. J Am Soc Nephrol 2021; 32:563-579. [PMID: 33514561 PMCID: PMC7920176 DOI: 10.1681/asn.2020081126] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 11/15/2020] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Previous research demonstrated that small Rho GTPases, modulators of the actin cytoskeleton, are drivers of podocyte foot-process effacement in glomerular diseases, such as FSGS. However, a comprehensive understanding of the regulatory networks of small Rho GTPases in podocytes is lacking. METHODS We conducted an analysis of podocyte transcriptome and proteome datasets for Rho GTPases; mapped in vivo, podocyte-specific Rho GTPase affinity networks; and examined conditional knockout mice and murine disease models targeting Srgap1. To evaluate podocyte foot-process morphology, we used super-resolution microscopy and electron microscopy; in situ proximity ligation assays were used to determine the subcellular localization of the small GTPase-activating protein SRGAP1. We performed functional analysis of CRISPR/Cas9-generated SRGAP1 knockout podocytes in two-dimensional and three-dimensional cultures and quantitative interaction proteomics. RESULTS We demonstrated SRGAP1 localization to podocyte foot processes in vivo and to cellular protrusions in vitro. Srgap1fl/fl*Six2Cre but not Srgap1fl/fl*hNPHS2Cre knockout mice developed an FSGS-like phenotype at adulthood. Podocyte-specific deletion of Srgap1 by hNPHS2Cre resulted in increased susceptibility to doxorubicin-induced nephropathy. Detailed analysis demonstrated significant effacement of podocyte foot processes. Furthermore, SRGAP1-knockout podocytes showed excessive protrusion formation and disinhibition of the small Rho GTPase machinery in vitro. Evaluation of a SRGAP1-dependent interactome revealed the involvement of SRGAP1 with protrusive and contractile actin networks. Analysis of glomerular biopsy specimens translated these findings toward human disease by displaying a pronounced redistribution of SRGAP1 in FSGS. CONCLUSIONS SRGAP1, a podocyte-specific RhoGAP, controls podocyte foot-process architecture by limiting the activity of protrusive, branched actin networks. Therefore, elucidating the complex regulatory small Rho GTPase affinity network points to novel targets for potentially precise intervention in glomerular diseases.
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Affiliation(s)
- Manuel Rogg
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany,Department of Medicine IV, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany
| | - Jasmin I. Maier
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany
| | - Robert Dotzauer
- Department of Medicine IV, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany
| | - Nadine Artelt
- Department of Anatomy and Cell Biology, University Medicine Greifswald, Greifswald, Germany
| | - Oliver Kretz
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Martin Helmstädter
- Department of Medicine IV, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany
| | - Ahmed Abed
- Department of Medicine IV, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany
| | - Alena Sammarco
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany
| | - August Sigle
- Department of Medicine IV, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany,Department of Urology, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany
| | - Dominik Sellung
- Department of Medicine IV, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany,Department of Neurology, Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany
| | - Patrick Dinse
- Department of Medicine IV, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany
| | - Karoline Reiche
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany
| | - Mako Yasuda-Yamahara
- Department of Medicine IV, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany,Department of Medicine, Shiga University of Medical Science, Otsu, Japan
| | - Martin L. Biniossek
- Institute of Molecular Medicine and Cell Research, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany
| | - Gerd Walz
- Department of Medicine IV, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany
| | - Martin Werner
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany
| | - Nicole Endlich
- Department of Anatomy and Cell Biology, University Medicine Greifswald, Greifswald, Germany
| | - Oliver Schilling
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany
| | - Tobias B. Huber
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christoph Schell
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany,Berta-Ottenstein Program, Medical Faculty, Medical Center – University of Freiburg, Freiburg, Germany
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44
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EPB41L5 controls podocyte extracellular matrix assembly by adhesome-dependent force transmission. Cell Rep 2021; 34:108883. [PMID: 33761352 DOI: 10.1016/j.celrep.2021.108883] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 12/21/2020] [Accepted: 02/25/2021] [Indexed: 12/14/2022] Open
Abstract
The integrity of the kidney filtration barrier essentially relies on the balanced interplay of podocytes and the glomerular basement membrane (GBM). Here, we show by analysis of in vitro and in vivo models that a loss of the podocyte-specific FERM-domain protein EPB41L5 results in impaired extracellular matrix (ECM) assembly. By using quantitative proteomics analysis of the secretome and matrisome, we demonstrate a shift in ECM composition characterized by diminished deposition of core GBM components, such as LAMA5. Integrin adhesome proteomics reveals that EPB41L5 recruits PDLIM5 and ACTN4 to integrin adhesion complexes (IACs). Consecutively, EPB41L5 knockout podocytes show insufficient maturation of integrin adhesion sites, which translates into impaired force transmission and ECM assembly. These observations build the framework for a model in which EPB41L5 functions as a cell-type-specific regulator of the podocyte adhesome and controls a localized adaptive module in order to prevent podocyte detachment and thereby ensures GBM integrity.
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45
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McWilliam SJ, Wright RD, Welsh GI, Tuffin J, Budge KL, Swan L, Wilm T, Martinas IR, Littlewood J, Oni L. The complex interplay between kidney injury and inflammation. Clin Kidney J 2021; 14:780-788. [PMID: 33777361 PMCID: PMC7986351 DOI: 10.1093/ckj/sfaa164] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 06/10/2020] [Indexed: 12/11/2022] Open
Abstract
Acute kidney injury (AKI) has gained significant attention following patient safety alerts about the increased risk of harm to patients, including increased mortality and hospitalization. Common causes of AKI include hypovolaemia, nephrotoxic medications, ischaemia and acute glomerulonephritis, although in reality it may be undetermined or multifactorial. A period of inflammation either as a contributor to the kidney injury or resulting from the injury is almost universally seen. This article was compiled following a workshop exploring the interplay between injury and inflammation. AKI is characterized by some degree of renal cell death through either apoptosis or necrosis, together with a strong inflammatory response. Studies interrogating the resolution of renal inflammation identify a whole range of molecules that are upregulated and confirm that the kidneys are able to intrinsically regenerate after an episode of AKI, provided the threshold of damage is not too high. Kidneys are unable to generate new nephrons, and dysfunctional or repeated episodes will lead to further nephron loss that is ultimately associated with the development of renal fibrosis and chronic kidney disease (CKD). The AKI to CKD transition is a complex process mainly facilitated by maladaptive repair mechanisms. Early biomarkers mapping out this process would allow a personalized approach to identifying patients with AKI who are at high risk of developing fibrosis and subsequent CKD. This review article highlights this process and explains how laboratory models of renal inflammation and injury assist with understanding the underlying disease process and allow interrogation of medications aimed at targeting the mechanistic interplay.
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Affiliation(s)
- Stephen J McWilliam
- Department of Paediatric Pharmacology, Alder Hey Children’s Hospital, Liverpool, UK
- Department of Women and Children’s Health, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Rachael D Wright
- Department of Women and Children’s Health, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Gavin I Welsh
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, UK
| | - Jack Tuffin
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, UK
| | - Kelly L Budge
- Department of Women and Children’s Health, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Laura Swan
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Thomas Wilm
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Ioana-Roxana Martinas
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - James Littlewood
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
- Department of Nephrology, Royal Liverpool University Hospital, Liverpool, UK
| | - Louise Oni
- Department of Women and Children’s Health, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
- Department of Paediatric Nephrology, Alder Hey Children’s NHS Foundation Trust Hospital, Liverpool, UK
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46
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van den Broek M, Smeets B, Schreuder MF, Jansen J. The podocyte as a direct target of glucocorticoids in nephrotic syndrome. Nephrol Dial Transplant 2021; 37:1808-1815. [PMID: 33515261 DOI: 10.1093/ndt/gfab016] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Indexed: 12/14/2022] Open
Abstract
Nephrotic syndrome (NS) is characterized by massive proteinuria; podocyte loss or altered function is a central event in its pathophysiology. Treatment with glucocorticoids is the mainstay of therapy. However, many patients experience one or multiple relapses and prolonged use may be associated with severe adverse effects. Recently, the beneficial effects of glucocorticoids have been attributed to a direct effect on podocytes in addition to the well-known immunosuppressive effects. The molecular effects of glucocorticoid action have been studied using animal and cell models of NS. This review provides a comprehensive overview of different molecular mediators regulated by glucocorticoids including an overview of the model systems that were used to study them. Glucocorticoids are described to stimulate podocyte recovery by restoring pro-survival signaling of slit diaphragm related proteins and limiting inflammatory responses. Of special interest is the effect of glucocorticoids on stabilizing the cytoskeleton of podocytes, since these effects are also described for other therapeutic agents used in NS, such as cyclosporin. Current models provide much insight, but do not fully recapitulate the human condition since the pathophysiology underlying NS is poorly understood. New and promising models include the glomerulus-on-a-chip and kidney organoids, which have the potential to be further developed into functional NS models in the future.
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Affiliation(s)
- Martijn van den Broek
- Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands.,Department of Pediatric Nephrology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Amalia Children's Hospital, Nijmegen, The Netherlands
| | - Bart Smeets
- Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands
| | - Michiel F Schreuder
- Department of Pediatric Nephrology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Amalia Children's Hospital, Nijmegen, The Netherlands
| | - Jitske Jansen
- Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands.,Department of Pediatric Nephrology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Amalia Children's Hospital, Nijmegen, The Netherlands
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47
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Gujarati NA, Vasquez JM, Bogenhagen DF, Mallipattu SK. The complicated role of mitochondria in the podocyte. Am J Physiol Renal Physiol 2020; 319:F955-F965. [PMID: 33073585 PMCID: PMC7792691 DOI: 10.1152/ajprenal.00393.2020] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 10/13/2020] [Accepted: 10/13/2020] [Indexed: 02/06/2023] Open
Abstract
Mitochondria play a complex role in maintaining cellular function including ATP generation, generation of biosynthetic precursors for macromolecules, maintenance of redox homeostasis, and metabolic waste management. Although the contribution of mitochondrial function in various kidney diseases has been studied, there are still avenues that need to be explored under healthy and diseased conditions. Mitochondrial damage and dysfunction have been implicated in experimental models of podocytopathy as well as in humans with glomerular diseases resulting from podocyte dysfunction. Specifically, in the podocyte, metabolism is largely driven by oxidative phosphorylation or glycolysis depending on the metabolic needs. These metabolic needs may change drastically in the presence of podocyte injury in glomerular diseases such as diabetic kidney disease or focal segmental glomerulosclerosis. Here, we review the role of mitochondria in the podocyte and the factors regulating its function at baseline and in a variety of podocytopathies to identify potential targets for therapy.
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Affiliation(s)
- Nehaben A Gujarati
- Division of Nephrology, Department of Medicine, Renaissance School of Medicine at Stony Brook University, Stony Brook, New York
| | - Jessica M Vasquez
- Division of Nephrology, Department of Medicine, Renaissance School of Medicine at Stony Brook University, Stony Brook, New York
| | - Daniel F Bogenhagen
- Department of Pharmacological Sciences, Renaissance School of Medicine at Stony Brook University, Stony Brook, New York
| | - Sandeep K Mallipattu
- Division of Nephrology, Department of Medicine, Renaissance School of Medicine at Stony Brook University, Stony Brook, New York
- Renal Section, Northport Department of Veterans Affairs Medical Center, Northport, New York
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48
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Matsuda J, Asano-Matsuda K, Kitzler TM, Takano T. Rho GTPase regulatory proteins in podocytes. Kidney Int 2020; 99:336-345. [PMID: 33122025 DOI: 10.1016/j.kint.2020.08.035] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 08/21/2020] [Accepted: 08/25/2020] [Indexed: 12/14/2022]
Abstract
The Rho family of small GTPases (Rho GTPases) are the master regulators of the actin cytoskeleton and consist of 22 members. Previous studies implicated dysregulation of Rho GTPases in podocytes in the pathogenesis of proteinuric glomerular diseases. Rho GTPases are primarily regulated by the three families of proteins; guanine nucleotide exchange factors (GEFs; 82 members), GTPase-activating proteins (GAPs; 69 members), and GDP dissociation inhibitors (GDIs; 3 members). Since the regulatory proteins far outnumber their substrate Rho GTPases and act in concert in a cell/context-dependent manner, the upstream regulatory mechanism directing Rho GTPases in podocytes is largely unknown. In this review, we summarize recent advances in the understanding of the role of Rho GTPase regulatory proteins in podocytes, including the known mutations of these proteins that cause proteinuria in humans. We also provide critical appraisal of the in vivo and in vitro studies and identify the knowledge gap in the field that will require further studies.
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Affiliation(s)
- Jun Matsuda
- Division of Nephrology, McGill University Health Centre, Montreal, Quebec, Canada; Research Institute, McGill University Health Centre, Montreal, Quebec, Canada
| | - Kana Asano-Matsuda
- Division of Nephrology, McGill University Health Centre, Montreal, Quebec, Canada; Research Institute, McGill University Health Centre, Montreal, Quebec, Canada
| | - Thomas M Kitzler
- Research Institute, McGill University Health Centre, Montreal, Quebec, Canada; Division of Medical Genetics, Department of Medicine, McGill University Health Centre, Montreal, Quebec, Canada; Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Tomoko Takano
- Division of Nephrology, McGill University Health Centre, Montreal, Quebec, Canada; Research Institute, McGill University Health Centre, Montreal, Quebec, Canada.
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Rinschen MM, Saez-Rodriguez J. The tissue proteome in the multi-omic landscape of kidney disease. Nat Rev Nephrol 2020; 17:205-219. [PMID: 33028957 DOI: 10.1038/s41581-020-00348-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/14/2020] [Indexed: 02/07/2023]
Abstract
Kidney research is entering an era of 'big data' and molecular omics data can provide comprehensive insights into the molecular footprints of cells. In contrast to transcriptomics, proteomics and metabolomics generate data that relate more directly to the pathological symptoms and clinical parameters observed in patients. Owing to its complexity, the proteome still holds many secrets, but has great potential for the identification of drug targets. Proteomics can provide information about protein synthesis, modification and degradation, as well as insight into the physical interactions between proteins, and between proteins and other biomolecules. Thus far, proteomics in nephrology has largely focused on the discovery and validation of biomarkers, but the systematic analysis of the nephroproteome can offer substantial additional insights, including the discovery of mechanisms that trigger and propagate kidney disease. Moreover, proteome acquisition might provide a diagnostic tool that complements the assessment of a kidney biopsy sample by a pathologist. Such applications are becoming increasingly feasible with the development of high-throughput and high-coverage technologies, such as versatile mass spectrometry-based techniques and protein arrays, and encourage further proteomics research in nephrology.
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Affiliation(s)
- Markus M Rinschen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark. .,III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany. .,Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany. .,Department of Chemistry, Scripps Center for Metabolomics and Mass Spectrometry, Scripps Research, La Jolla, CA, USA.
| | - Julio Saez-Rodriguez
- Institute for Computational Biomedicine, Faculty of Medicine, Heidelberg University, and Heidelberg University Hospital, Bioquant, Heidelberg, Germany.,Joint Research Center for Computational Biomedicine, RWTH Aachen University Hospital, Aachen, Germany.,Molecular Medicine Partnership Unit, European Molecular Biology Laboratory and Heidelberg University, Heidelberg, Germany
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Struk T, Nair V, Eichinger F, Kretzler M, Wedlich-Söldner R, Bayraktar S, Pavenstädt H. Transcriptome analysis of primary podocytes reveals novel calcium regulated regulatory networks. FASEB J 2020; 34:14490-14506. [PMID: 32931033 DOI: 10.1096/fj.201902493rr] [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: 10/05/2019] [Revised: 08/11/2020] [Accepted: 08/14/2020] [Indexed: 11/11/2022]
Abstract
Podocytes are pivotal in establishing the selective permeability of the glomerular filtration barrier. Recently, we showed that an increase of the intracellular calcium ion concentration [Ca2+ ] causes a rapid and transient actin reset (CaAR) measurable through live imaging microscopy using lifeact-mCherry as an actin dye in different cell types including the podocyte. This and other studies show the critical role [Ca2+ ] and the actin cytoskeleton play in podocyte homeostasis. To further investigate the role of [Ca2+ ] and the actin cytoskeleton in podocytes, we used a double fluorescent reporter mouse model to establish a primary podocyte culture system. We treated these podocytes temporarily with a Calcium Ionophore and facultatively with Latrunculin A, an inhibitor of actin polymerization. Unbiased genome wide transcriptional analysis identified a transcriptional response in podocytes to elevated [Ca2+ ] levels, affecting mRNA levels of PDGF-BB, RICTOR, and MIR17HG as mediators of Ca2+ -signaling. Comparison of the ex vivo transcriptional response from the primary podocyte culture with glomerular transcripts across a wide spectrum of CKD disease confirmed co-regulation of transcript sets, establishing the disease relevance of the model system. Our findings demonstrate novel [Ca2+ ] regulated gene networks in podocytes deepening our understanding of podocyte biology and disease.
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Affiliation(s)
- Thaddäus Struk
- Department of Medicine, University of Münster, Münster, Germany
| | - Viji Nair
- Michigan Kidney Translational Medical Core, University of Michigan, Ann Arbor, MI, USA
| | - Felix Eichinger
- Michigan Kidney Translational Medical Core, University of Michigan, Ann Arbor, MI, USA
| | - Matthias Kretzler
- Michigan Kidney Translational Medical Core, University of Michigan, Ann Arbor, MI, USA.,Internal Medicine, Department of Nephrology, University of Michigan, Ann Arbor, MI, USA
| | | | - Samet Bayraktar
- Department of Medicine, University of Münster, Münster, Germany
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