1
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Watanabe M, Ishii Y, Hashimoto K, Takimoto HR, Sasaki N. Development and Characterization of a Novel FVB- PrkdcR2140C Mouse Model for Adriamycin-Induced Nephropathy. Genes (Basel) 2024; 15:456. [PMID: 38674390 PMCID: PMC11049318 DOI: 10.3390/genes15040456] [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: 02/27/2024] [Revised: 03/29/2024] [Accepted: 04/02/2024] [Indexed: 04/28/2024] Open
Abstract
The Adriamycin (ADR) nephropathy model, which induces podocyte injury, is limited to certain mouse strains due to genetic susceptibilities, such as the PrkdcR2140C polymorphism. The FVB/N strain without the R2140C mutation resists ADR nephropathy. Meanwhile, a detailed analysis of the progression of ADR nephropathy in the FVB/N strain has yet to be conducted. Our research aimed to create a novel mouse model, the FVB-PrkdcR2140C, by introducing PrkdcR2140C into the FVB/NJcl (FVB) strain. Our study showed that FVB-PrkdcR2140C mice developed severe renal damage when exposed to ADR, as evidenced by significant albuminuria and tubular injury, exceeding the levels observed in C57BL/6J (B6)-PrkdcR2140C. This indicates that the FVB/N genetic background, in combination with the R2140C mutation, strongly predisposes mice to ADR nephropathy, highlighting the influence of genetic background on disease susceptibility. Using RNA sequencing and subsequent analysis, we identified several genes whose expression is altered in response to ADR nephropathy. In particular, Mmp7, Mmp10, and Mmp12 were highlighted for their differential expression between strains and their potential role in influencing the severity of kidney damage. Further genetic analysis should lead to identifying ADR nephropathy modifier gene(s), aiding in early diagnosis and providing novel approaches to kidney disease treatment and prevention.
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Affiliation(s)
| | | | | | | | - Nobuya Sasaki
- Laboratory of Laboratory Animal Science and Medicine, School of Veterinary Medicine, Kitasato University, Towada 034-8628, Japan
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2
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Empitu MA, Kikyo M, Shirata N, Yamada H, Makino SI, Kadariswantiningsih IN, Aizawa M, Patrakka J, Nishimori K, Asanuma K. Inhibition of Importin- α -Mediated Nuclear Localization of Dendrin Attenuates Podocyte Loss and Glomerulosclerosis. J Am Soc Nephrol 2023; 34:1222-1239. [PMID: 37134307 PMCID: PMC10356163 DOI: 10.1681/asn.0000000000000150] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 03/27/2023] [Indexed: 05/05/2023] Open
Abstract
SIGNIFICANCE STATEMENT Nuclear translocation of dendrin is observed in injured podocytes, but the mechanism and its consequence are unknown. In nephropathy mouse models, dendrin ablation attenuates proteinuria, podocyte loss, and glomerulosclerosis. The nuclear translocation of dendrin promotes c-Jun N -terminal kinase phosphorylation in podocytes, altering focal adhesion and enhancing cell detachment-induced apoptosis. We identified mediation of dendrin nuclear translocation by nuclear localization signal 1 (NLS1) sequence and adaptor protein importin- α . Inhibition of importin- α prevents nuclear translocation of dendrin, decreases podocyte loss, and attenuates glomerulosclerosis in nephropathy models. Thus, inhibiting importin- α -mediated nuclear translocation of dendrin is a potential strategy to halt podocyte loss and glomerulosclerosis. BACKGROUND Nuclear translocation of dendrin is observed in the glomeruli in numerous human renal diseases, but the mechanism remains unknown. This study investigated that mechanism and its consequence in podocytes. METHODS The effect of dendrin deficiency was studied in adriamycin (ADR) nephropathy model and membrane-associated guanylate kinase inverted 2 ( MAGI2 ) podocyte-specific knockout ( MAGI2 podKO) mice. The mechanism and the effect of nuclear translocation of dendrin were studied in podocytes overexpressing full-length dendrin and nuclear localization signal 1-deleted dendrin. Ivermectin was used to inhibit importin- α . RESULTS Dendrin ablation reduced albuminuria, podocyte loss, and glomerulosclerosis in ADR-induced nephropathy and MAGI2 podKO mice. Dendrin deficiency also prolonged the lifespan of MAGI2 podKO mice. Nuclear dendrin promoted c-Jun N -terminal kinase phosphorylation that subsequently altered focal adhesion, reducing cell attachment and enhancing apoptosis in cultured podocytes. Classical bipartite nuclear localization signal sequence and importin- α mediate nuclear translocation of dendrin. The inhibition of importin- α / β reduced dendrin nuclear translocation and apoptosis in vitro as well as albuminuria, podocyte loss, and glomerulosclerosis in ADR-induced nephropathy and MAGI2 podKO mice. Importin- α 3 colocalized with nuclear dendrin in the glomeruli of FSGS and IgA nephropathy patients. CONCLUSIONS Nuclear translocation of dendrin promotes cell detachment-induced apoptosis in podocytes. Therefore, inhibiting importin- α -mediated dendrin nuclear translocation is a potential strategy to prevent podocyte loss and glomerulosclerosis.
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Affiliation(s)
- Maulana A. Empitu
- Department of Nephrology, Graduate School of Medicine, Chiba University, Chiba, Japan
- Faculty of Medicine, Airlangga University, Surabaya, Indonesia
| | - Mitsuhiro Kikyo
- Sohyaku, Innovative Research Division, Mitsubishi Tanabe Pharmaceutical Corporation, Kanagawa, Japan
- Medical Innovation Center, TMK Project, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Naritoshi Shirata
- Sohyaku, Innovative Research Division, Mitsubishi Tanabe Pharmaceutical Corporation, Kanagawa, Japan
- Medical Innovation Center, TMK Project, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Hiroyuki Yamada
- Department of Nephrology, Graduate School of Medicine, Chiba University, Chiba, Japan
- Medical Innovation Center, TMK Project, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Department of Nephrology, Kyoto University Hospital, Kyoto, Japan
| | - Shin-ichi Makino
- Department of Nephrology, Graduate School of Medicine, Chiba University, Chiba, Japan
- Medical Innovation Center, TMK Project, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Department of Nephrology, Kyoto University Hospital, Kyoto, Japan
| | - Ika N. Kadariswantiningsih
- Department of Nephrology, Graduate School of Medicine, Chiba University, Chiba, Japan
- Faculty of Medicine, Airlangga University, Surabaya, Indonesia
| | - Masashi Aizawa
- Department of Nephrology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Jaakko Patrakka
- Karolinska Institute/AstraZeneca Integrated Cardio Metabolic Center (ICMC), Huddinge, Sweden
- Division of Pathology, Department of Laboratory Medicine, Karolinska University Hospital Huddinge, Huddinge, Sweden
| | - Katsuhiko Nishimori
- Department of Bioregulation and Pharmacological Medicine and Department of Obesity and Internal Inflammation, Fukushima Medical University, Fukushima, Japan
| | - Katsuhiko Asanuma
- Department of Nephrology, Graduate School of Medicine, Chiba University, Chiba, Japan
- Medical Innovation Center, TMK Project, Graduate School of Medicine, Kyoto University, Kyoto, Japan
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3
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Levin A, Schwarz A, Hulkko J, He L, Sun Y, Barany P, Bruchfeld A, Herthelius M, Wennberg L, Ebefors K, Patrakka J, Betsholtz C, Nyström J, Mölne J, Hultenby K, Witasp A, Wernerson A. The role of dendrin in IgA nephropathy. Nephrol Dial Transplant 2022; 38:311-321. [PMID: 35767852 PMCID: PMC9923709 DOI: 10.1093/ndt/gfac208] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Immunoglobulin A nephropathy (IgAN) and its systemic variant IgA vasculitis (IgAV) damage the glomeruli, resulting in proteinuria, hematuria and kidney impairment. Dendrin is a podocyte-specific protein suggested to be involved in the pathogenesis of IgAN. Upon cell injury, dendrin translocates from the slit diaphragm to the nucleus, where it is suggested to induce apoptosis and cytoskeletal changes, resulting in proteinuria and accelerated disease progression in mice. Here we investigated gene and protein expression of dendrin in relation to clinical and histopathological findings to further elucidate its role in IgAN/IgAV. METHODS Glomerular gene expression was measured using microarray on 30 IgAN/IgAV patients, 5 patients with membranous nephropathy (MN) and 20 deceased kidney donors. Dendrin was spatially evaluated on kidney tissue sections by immunofluorescence (IF) staining (IgAN patients, n = 4; nephrectomized kidneys, n = 3) and semi-quantified by immunogold electron microscopy (IgAN/IgAV patients, n = 21; MN, n = 5; living kidney donors, n = 6). Histopathological grading was performed according to the Oxford and Banff classifications. Clinical data were collected at the time of biopsy and follow-up. RESULTS Dendrin mRNA levels were higher (P = .01) in IgAN patients compared with MN patients and controls and most prominently in patients with preserved kidney function and fewer chronic histopathological changes. Whereas IF staining did not differ between groups, immunoelectron microscopy revealed that a higher relative nuclear dendrin concentration in IgAN patients was associated with a slower annual progression rate and milder histopathological changes. CONCLUSION Dendrin messenger RNA levels and relative nuclear protein concentrations are increased and associated with a more benign phenotype and progression in IgAN/IgAV patients.
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Affiliation(s)
| | - Angelina Schwarz
- Department of Clinical Science, Intervention and Technology, Divison of Renal Medicine, Karolinska Institutet, Stockholm, Sweden
| | | | - Liqun He
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Ying Sun
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Peter Barany
- Department of Clinical Science, Intervention and Technology, Divison of Renal Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Annette Bruchfeld
- Department of Clinical Science, Intervention and Technology, Divison of Renal Medicine, Karolinska Institutet, Stockholm, Sweden,Department of Health, Medicine and Caring Sciences, Linköpings Universitet Hälsouniversitetet, Linkoping, Sweden
| | - Maria Herthelius
- Department of Clinical Science, Intervention, and Technology, Division of Pediatrics, Karolinska Institutet, Stockholm, Sweden
| | - Lars Wennberg
- Department of Clinical Science, Intervention and Technology, Division of Transplantation Surgery, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Kerstin Ebefors
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Jaakko Patrakka
- Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Christer Betsholtz
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Jenny Nyström
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Johan Mölne
- Department of Laboratory Medicine, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Kjell Hultenby
- Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
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4
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Mizdrak M, Kumrić M, Kurir TT, Božić J. Emerging Biomarkers for Early Detection of Chronic Kidney Disease. J Pers Med 2022; 12:jpm12040548. [PMID: 35455664 PMCID: PMC9025702 DOI: 10.3390/jpm12040548] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 03/22/2022] [Accepted: 03/28/2022] [Indexed: 12/14/2022] Open
Abstract
Chronic kidney disease (CKD) is a major and serious global health problem that leads to kidney damage as well as multiple systemic diseases. Early diagnosis and treatment are two major measures to prevent further deterioration of kidney function and to delay adverse outcomes. However, the paucity of early, predictive and noninvasive biomarkers has undermined our ability to promptly detect and treat this common clinical condition which affects more than 10% of the population worldwide. Despite all limitations, kidney function is still measured by serum creatinine, cystatin C, and albuminuria, as well as estimating glomerular filtration rate using different equations. This review aims to provide comprehensive insight into diagnostic methods available for early detection of CKD. In the review, we discuss the following topics: (i) markers of glomerular injury; (ii) markers of tubulointerstitial injury; (iii) the role of omics; (iv) the role of microbiota; (v) and finally, the role of microRNA in the early detection of CKD. Despite all novel findings, none of these biomarkers have met the criteria of an ideal early marker. Since the central role in CKD progression is the proximal tubule (PT), most data from the literature have analyzed biomarkers of PT injury, such as KIM-1 (kidney injury molecule-1), NGAL (neutrophil gelatinase-associated lipocalin), and L-FABP (liver fatty acid-binding protein).
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Affiliation(s)
- Maja Mizdrak
- Department of Nephrology and Hemodialysis, University Hospital of Split, 21000 Split, Croatia;
- Department of Pathophysiology, University of Split School of Medicine, 21000 Split, Croatia; (M.K.); (T.T.K.)
| | - Marko Kumrić
- Department of Pathophysiology, University of Split School of Medicine, 21000 Split, Croatia; (M.K.); (T.T.K.)
| | - Tina Tičinović Kurir
- Department of Pathophysiology, University of Split School of Medicine, 21000 Split, Croatia; (M.K.); (T.T.K.)
- Department of Endocrinology, Diabetes and Metabolic Disorders, University Hospital of Split, 21000 Split, Croatia
| | - Joško Božić
- Department of Pathophysiology, University of Split School of Medicine, 21000 Split, Croatia; (M.K.); (T.T.K.)
- Correspondence:
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5
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Agarwal S, Sudhini YR, Polat OK, Reiser J, Altintas MM. Renal cell markers: lighthouses for managing renal diseases. Am J Physiol Renal Physiol 2021; 321:F715-F739. [PMID: 34632812 DOI: 10.1152/ajprenal.00182.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Kidneys, one of the vital organs in our body, are responsible for maintaining whole body homeostasis. The complexity of renal function (e.g., filtration, reabsorption, fluid and electrolyte regulation, and urine production) demands diversity not only at the level of cell types but also in their overall distribution and structural framework within the kidney. To gain an in depth molecular-level understanding of the renal system, it is imperative to discern the components of kidney and the types of cells residing in each of the subregions. Recent developments in labeling, tracing, and imaging techniques have enabled us to mark, monitor, and identify these cells in vivo with high efficiency in a minimally invasive manner. In this review, we summarize different cell types, specific markers that are uniquely associated with those cell types, and their distribution in the kidney, which altogether make kidneys so special and different. Cellular sorting based on the presence of certain proteins on the cell surface allowed for the assignment of multiple markers for each cell type. However, different studies using different techniques have found contradictions in cell type-specific markers. Thus, the term "cell marker" might be imprecise and suboptimal, leading to uncertainty when interpreting the data. Therefore, we strongly believe that there is an unmet need to define the best cell markers for a cell type. Although the compendium of renal-selective marker proteins presented in this review is a resource that may be useful to researchers, we acknowledge that the list may not be necessarily exhaustive.
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Affiliation(s)
- Shivangi Agarwal
- Department of Internal Medicine, Rush University, Chicago, Illinois
| | | | - Onur K Polat
- Department of Internal Medicine, Rush University, Chicago, Illinois
| | - Jochen Reiser
- Department of Internal Medicine, Rush University, Chicago, Illinois
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6
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Haley KE, Elshani M, Um IH, Bell C, Caie PD, Harrison DJ, Reynolds PA. YAP Translocation Precedes Cytoskeletal Rearrangement in Podocyte Stress Response: A Podometric Investigation of Diabetic Nephropathy. Front Physiol 2021; 12:625762. [PMID: 34335284 PMCID: PMC8320019 DOI: 10.3389/fphys.2021.625762] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 05/21/2021] [Indexed: 11/13/2022] Open
Abstract
Podocyte loss plays a pivotal role in the pathogenesis of glomerular disease. However, the mechanisms underlying podocyte damage and loss remain poorly understood. Although detachment of viable cells has been documented in experimental Diabetic Nephropathy, correlations between reduced podocyte density and disease severity have not yet been established. YAP, a mechanosensing protein, has recently been shown to correlate with glomerular disease progression, however, the underlying mechanism has yet to be fully elucidated. In this study, we sought to document podocyte density in Diabetic Nephropathy using an amended podometric methodology, and to investigate the interplay between YAP and cytoskeletal integrity during podocyte injury. Podocyte density was quantified using TLE4 and GLEPP1 multiplexed immunofluorescence. Fourteen Diabetic Nephropathy cases were analyzed for both podocyte density and cytoplasmic translocation of YAP via automated image analysis. We demonstrate a significant decrease in podocyte density in Grade III/IV cases (124.5 per 106 μm3) relative to Grade I/II cases (226 per 106 μm3) (Student's t-test, p < 0.001), and further show that YAP translocation precedes cytoskeletal rearrangement following injury. Based on these findings we hypothesize that a significant decrease in podocyte density in late grade Diabetic Nephropathy may be explained by early cytoplasmic translocation of YAP.
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Affiliation(s)
- Kathryn E Haley
- School of Medicine, University of St Andrews, St Andrews, United Kingdom.,Biomedical Sciences Research Complex (BSRC), University of St Andrews, St Andrews, United Kingdom
| | - Mustafa Elshani
- School of Medicine, University of St Andrews, St Andrews, United Kingdom.,Directorate of Laboratory Medicine, Lothian University Hospitals Trust, Royal Infirmary, Edinburgh, United Kingdom
| | - In Hwa Um
- School of Medicine, University of St Andrews, St Andrews, United Kingdom
| | - Cameron Bell
- School of Medicine, University of St Andrews, St Andrews, United Kingdom.,Acute Internal Medicine, Queen Elizabeth University Hospital, Glasgow, United Kingdom
| | - Peter D Caie
- School of Medicine, University of St Andrews, St Andrews, United Kingdom
| | - David J Harrison
- School of Medicine, University of St Andrews, St Andrews, United Kingdom.,Directorate of Laboratory Medicine, Lothian University Hospitals Trust, Royal Infirmary, Edinburgh, United Kingdom
| | - Paul A Reynolds
- School of Medicine, University of St Andrews, St Andrews, United Kingdom.,Biomedical Sciences Research Complex (BSRC), University of St Andrews, St Andrews, United Kingdom
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7
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Ning L, Suleiman HY, Miner JH. Synaptopodin deficiency exacerbates kidney disease in a mouse model of Alport syndrome. Am J Physiol Renal Physiol 2021; 321:F12-F25. [PMID: 34029143 DOI: 10.1152/ajprenal.00035.2021] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Synaptopodin (Synpo) is an actin-associated protein in podocyte foot processes. By generating mice that completely lack Synpo, we previously showed that Synpo is dispensable for normal kidney function. However, lack of Synpo worsened adriamycin-induced nephropathy, indicating a protective role for Synpo in injured podocytes. Here, we investigated whether lack of Synpo directly impacts a genetic disease, Alport syndrome (AS), because Synpo is reduced in podocytes of affected humans and mice; whether this is merely an association or pathogenic is unknown. We used collagen type IV-α5 (Col4a5) mutant mice, which model X-linked AS, showing glomerular basement membrane (GBM) abnormalities, eventual foot process effacement, and progression to end-stage kidney disease. We intercrossed mice carrying mutations in Synpo and Col4a5 to produce double-mutant mice. Urine and tissue were taken at select time points to evaluate albuminuria, histopathology, and glomerular capillary wall composition and ultrastructure. Lack of Synpo in Col4a5-/Y, Col4a5-/-, or Col4a5+/- Alport mice led to the acceleration of disease progression, including more severe proteinuria and glomerulosclerosis. Absence of Synpo attenuated the shift of myosin IIA from the podocyte cell body and major processes to actin cables near the GBM in the areas of effacement. We speculate that this is mechanistically associated with enhanced loss of podocytes due to easier detachment from the GBM. We conclude that Synpo deletion exacerbates the disease phenotype in Alport mice, revealing the podocyte actin cytoskeleton as a target for therapy in patients with AS.NEW & NOTEWORTHY Alport syndrome (AS) is a hereditary disease of the glomerular basement with hematuria and proteinuria. Podocytes eventually exhibit foot process effacement, indicating actin cytoskeletal changes. To investigate how cytoskeletal changes impact podocytes, we generated Alport mice lacking synaptopodin, an actin-binding protein in foot processes. Analysis showed a more rapid disease progression, demonstrating that synaptopodin is protective. This suggests that the actin cytoskeleton is a target for therapy in AS and perhaps other glomerular diseases.
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Affiliation(s)
- Liang Ning
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Hani Y Suleiman
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Jeffrey H Miner
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
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8
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Racetin A, Filipović N, Lozić M, Ogata M, Gudelj Ensor L, Kelam N, Kovačević P, Watanabe K, Katsuyama Y, Saraga-Babić M, Glavina Durdov M, Vukojević K. A Homozygous Dab1 -/- Is a Potential Novel Cause of Autosomal Recessive Congenital Anomalies of the Mice Kidney and Urinary Tract. Biomolecules 2021; 11:biom11040609. [PMID: 33924028 PMCID: PMC8073787 DOI: 10.3390/biom11040609] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 04/14/2021] [Accepted: 04/19/2021] [Indexed: 01/09/2023] Open
Abstract
This study aimed to explore morphology changes in the kidneys of Dab1−/− (yotari) mice, as well as expression patterns of reelin, NOTCH2, LC3B, and cleaved caspase3 (CASP3) proteins, as potential determinants of normal kidney formation and function. We assumed that Dab1 functional inactivation may cause disorder in a wide spectrum of congenital anomalies of the kidney and urinary tract (CAKUT). Animals were sacrificed at postnatal days P4, P11, and P14. Paraffin-embedded kidney tissues were sectioned and analyzed by immunohistochemistry using specific antibodies. Kidney specimens were examined by bright-field, fluorescence, and electron microscopy. Data were analyzed by two-way ANOVA and t-tests. We noticed that yotari kidneys were smaller in size with a reduced diameter of nephron segments and thinner cortex. TEM microphotographs revealed foot process effacement in the glomeruli (G) of yotari mice, whereas aberrations in the structure of proximal convoluted tubules (PCT) and distal convoluted tubules (DCT) were not observed. A significant increase in reelin expression, NOTCH2, LC3B and cleaved CASP3 proteins was observed in the glomeruli of yotari mice. Renal hypoplasia in conjunction with foot process effacement and elevation in the expression of examined proteins in the glomeruli revealed CAKUT phenotype and loss of functional kidney tissue of yotari.
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Affiliation(s)
- Anita Racetin
- Department of Anatomy, Histology and Embryology, University of Split School of Medicine, 21000 Split, Croatia; (A.R.); (N.F.); (M.L.); (L.G.E.); (N.K.); (M.S.-B.)
- Department of Medical Genetics, School of Medicine, University of Mostar, 88000 Mostar, Bosnia and Herzegovina;
| | - Natalija Filipović
- Department of Anatomy, Histology and Embryology, University of Split School of Medicine, 21000 Split, Croatia; (A.R.); (N.F.); (M.L.); (L.G.E.); (N.K.); (M.S.-B.)
| | - Mirela Lozić
- Department of Anatomy, Histology and Embryology, University of Split School of Medicine, 21000 Split, Croatia; (A.R.); (N.F.); (M.L.); (L.G.E.); (N.K.); (M.S.-B.)
| | - Masaki Ogata
- Division of Anatomy, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, Sendai, Miyagi 981-8558, Japan;
| | - Larissa Gudelj Ensor
- Department of Anatomy, Histology and Embryology, University of Split School of Medicine, 21000 Split, Croatia; (A.R.); (N.F.); (M.L.); (L.G.E.); (N.K.); (M.S.-B.)
| | - Nela Kelam
- Department of Anatomy, Histology and Embryology, University of Split School of Medicine, 21000 Split, Croatia; (A.R.); (N.F.); (M.L.); (L.G.E.); (N.K.); (M.S.-B.)
| | - Petra Kovačević
- Department of Medical Genetics, School of Medicine, University of Mostar, 88000 Mostar, Bosnia and Herzegovina;
| | - Koichiro Watanabe
- Department of Anatomy, Shiga University of Medical Science, Ötsu 520-2192, Japan; (K.W.); (Y.K.)
| | - Yu Katsuyama
- Department of Anatomy, Shiga University of Medical Science, Ötsu 520-2192, Japan; (K.W.); (Y.K.)
| | - Mirna Saraga-Babić
- Department of Anatomy, Histology and Embryology, University of Split School of Medicine, 21000 Split, Croatia; (A.R.); (N.F.); (M.L.); (L.G.E.); (N.K.); (M.S.-B.)
| | | | - Katarina Vukojević
- Department of Anatomy, Histology and Embryology, University of Split School of Medicine, 21000 Split, Croatia; (A.R.); (N.F.); (M.L.); (L.G.E.); (N.K.); (M.S.-B.)
- Department of Medical Genetics, School of Medicine, University of Mostar, 88000 Mostar, Bosnia and Herzegovina;
- Correspondence: ; Tel.: +385-21-557-807; Fax: +385-1-557-811
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9
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Makino SI, Shirata N, Oliva Trejo JA, Yamamoto-Nonaka K, Yamada H, Miyake T, Mori K, Nakagawa T, Tashiro Y, Yamashita H, Yanagita M, Takahashi R, Asanuma K. Impairment of Proteasome Function in Podocytes Leads to CKD. J Am Soc Nephrol 2021; 32:597-613. [PMID: 33510039 PMCID: PMC7920174 DOI: 10.1681/asn.2019101025] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 11/20/2020] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND The ubiquitin-proteasome system (UPS) and the autophagy-lysosomal system (APLS) are major intracellular degradation procedures. The importance of the APLS in podocytes is established, but the role of the UPS is not well understood. METHODS To investigate the role of the UPS in podocytes, mice were generated that had deletion of Rpt3 (Rpt3pdKO), which encodes an essential regulatory subunit required for construction of the 26S proteasome and its deubiquitinating function. RESULTS Rpt3pdKO mice showed albuminuria and glomerulosclerosis, leading to CKD. Impairment of proteasome function caused accumulation of ubiquitinated proteins and of oxidative modified proteins, and it induced podocyte apoptosis. Although impairment of proteasome function normally induces autophagic activity, the number of autophagosomes was lower in podocytes of Rpt3pdKO mice than in control mice, suggesting the autophagic activity was suppressed in podocytes with impairment of proteasome function. In an in vitro study, antioxidant apocynin and autophagy activator rapamycin suppressed podocyte apoptosis induced by proteasome inhibition. Moreover, rapamycin ameliorated the glomerular injury in the Rpt3pdKO mice. The accumulation of ubiquitinated proteins and of oxidative modified proteins, which were detected in the podocytes of Rpt3pdKO mice, is a characteristic feature of aging. An aging marker was increased in the podocytes of Rpt3pdKO mice, suggesting that impairment of proteasome function promoted signs of aging in podocytes. CONCLUSIONS Impairment of proteasome function in podocytes led to CKD, and antioxidants and autophagy activators can be therapeutic agents for age-dependent CKD.
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Affiliation(s)
- Shin-ichi Makino
- Department of Nephrology, Graduate School of Medicine, Chiba University, Chiba, Japan,The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan,Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Naritoshi Shirata
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan,Sohyaku, Innovative Research Division, Mitsubishi Tanabe Pharmaceutical Corporation, Saitama, Japan
| | - Juan Alejandro Oliva Trejo
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan,Department of Cellular and Molecular Neuropathology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Kanae Yamamoto-Nonaka
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan,Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Hiroyuki Yamada
- Department of Nephrology, Graduate School of Medicine, Chiba University, Chiba, Japan,The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan,Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Takafumi Miyake
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan,Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Kiyoshi Mori
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan,Department of Molecular and Clinical Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan,Department of Nephrology, Shizuoka General Hospital, Shizuoka, Japan
| | - Takahiko Nakagawa
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan,Department of Nephrology, Rakuwakai Otowa Hospital, Kyoto, Japan
| | - Yoshitaka Tashiro
- Department of Neurology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Hirofumi Yamashita
- Department of Neurology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Motoko Yanagita
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan,Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan,Institute for the Advanced Study of Human Biology, Kyoto University, Kyoto, Japan
| | - Ryosuke Takahashi
- Department of Neurology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Katsuhiko Asanuma
- Department of Nephrology, Graduate School of Medicine, Chiba University, Chiba, Japan,The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan
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10
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Wei H, Wang J, Liang Z. STAT1-p53-p21axis-dependent stress-induced progression of chronic nephrosis in adriamycin-induced mouse model. ANNALS OF TRANSLATIONAL MEDICINE 2020; 8:1002. [PMID: 32953802 PMCID: PMC7475511 DOI: 10.21037/atm-20-5167] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Background Chronic nephrosis (CN) is an aging-related disease with high mortality. Signal transduction and transcriptional activator 1 (STAT1) protein promotes senescence in human glomerular mesangial cells (HMCs), but whether it affects the progression of adriamycin (ADR)-induced CN in vivo remains unclear. Methods We established an ADR-induced CN mouse model that was completed in wild-type (wt) mice by a single intravenous injection of 10 mg/kg ADR for 2 or 4 weeks. Clinical indexes in each group were determined. Hematoxylin and eosin staining (H&E) was employed to determine renal histopathological damage, SA-β-gal staining was used to evaluate cell senescence phenotype. TUNEL and immunohistochemistry (IHC) staining were used to detect renal apoptosis. Protein levels of Bcl-2, Bax, STAT1, p53 and p21 were measured by Western Blot. Results STAT1 intervention ameliorated renal function. H&E staining indicated that STAT1-deficient (stat1−/−) improved the renal tubular injury, and stat1−/− obviously inhibited the apoptosis and Caspase-3+ number in kidney tissues. Besides, stat1−/− decreased proteinuria, and the levels of urea nitrogen and creatinine as well as that of reactive oxygen species induced by ADR. Also, stat1−/− resulted in the reduced expression of p53 and p21. Conclusions Our current study strongly demonstrated the involvement of the STAT1-p53-p21 axis in the regulation of CN and is a potential target for the nephrosis treatment.
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Affiliation(s)
- Hua Wei
- Nephrology Department, Xinxiang Central Hospital, Xinxiang, China
| | - Jiali Wang
- Nephrology Department, Xinxiang Central Hospital, Xinxiang, China
| | - Zhaozhi Liang
- Nephrology Department, Xinxiang Central Hospital, Xinxiang, China
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11
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Ning L, Suleiman HY, Miner JH. Synaptopodin Is Dispensable for Normal Podocyte Homeostasis but Is Protective in the Context of Acute Podocyte Injury. J Am Soc Nephrol 2020; 31:2815-2832. [PMID: 32938649 DOI: 10.1681/asn.2020050572] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 07/27/2020] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Synaptopodin (Synpo) is an actin-associated protein in podocytes and dendritic spines. Many functions in regulating the actin cytoskeleton via RhoA and other pathways have been ascribed to Synpo, yet no pathogenic mutations in the SYNPO gene have been discovered in patients. Naturally occurring Synpo isoforms are known (Synpo-short and -long), and a novel truncated version (Synpo-T) is upregulated in podocytes from Synpo mutant mice. Synpo-T maintains some Synpo functions, which may prevent a podocyte phenotype from emerging in unchallenged mutant mice. METHODS Novel mouse models were generated to further investigate the functions of Synpo. In one, CRISPR/Cas9 deleted most of the Synpo gene, preventing production of any detectable Synpo protein. Two other mutant strains made truncated versions of the protein. Adriamycin injections were used to challenge the mice, and Synpo functions were investigated in primary cultured podocytes. RESULTS Mice that could not make detectable Synpo (Synpo -/- ) did not develop any kidney abnormalities up to 12 months of age. However, Synpo -/- mice were more susceptible to Adriamycin nephropathy. In cultured primary podocytes from mutant mice, the absence of Synpo caused loss of stress fibers, increased the number and size of focal adhesions, and impaired cell migration. Furthermore, loss of Synpo led to decreased RhoA activity and increased Rac1 activation. CONCLUSIONS In contrast to previous findings, podocytes can function normally in vivo in the absence of any Synpo isoform. Synpo plays a protective role in the context of podocyte injury through its involvement in actin reorganization and focal adhesion dynamics.
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Affiliation(s)
- Liang Ning
- Division of Nephrology, Washington University School of Medicine, St. Louis, Missouri
| | - Hani Y Suleiman
- Division of Nephrology, Washington University School of Medicine, St. Louis, Missouri
| | - Jeffrey H Miner
- Division of Nephrology, Washington University School of Medicine, St. Louis, Missouri
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12
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Usui T, Morito N, Shawki HH, Sato Y, Tsukaguchi H, Hamada M, Jeon H, Yadav MK, Kuno A, Tsunakawa Y, Okada R, Ojima T, Kanai M, Asano K, Imamura Y, Koshida R, Yoh K, Usui J, Yokoi H, Kasahara M, Yoshimura A, Muratani M, Kudo T, Oishi H, Yamagata K, Takahashi S. Transcription factor MafB in podocytes protects against the development of focal segmental glomerulosclerosis. Kidney Int 2020; 98:391-403. [DOI: 10.1016/j.kint.2020.02.038] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 02/21/2020] [Accepted: 02/28/2020] [Indexed: 12/31/2022]
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13
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Ji Z, Li H, Yang Z, Huang X, Ke X, Ma S, Lin Z, Lu Y, Zhang M. Kibra Modulates Learning and Memory via Binding to Dendrin. Cell Rep 2020; 26:2064-2077.e7. [PMID: 30784589 DOI: 10.1016/j.celrep.2019.01.097] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 01/08/2019] [Accepted: 01/25/2019] [Indexed: 10/27/2022] Open
Abstract
Kibra is a synaptic scaffold protein regulating learning and memory. Alterations of Kibra-encoding gene WWC1 cause various neuronal disorders, including Alzheimer's disease and Tourette syndrome. However, the molecular mechanism underlying Kibra's function in neurons is poorly understood. Here we discover that Kibra, via its N-terminal WW12 tandem domains, binds to a postsynaptic density enriched protein, Dendrin, with a nanomolar dissociation constant. On the basis of the structure of Kibra WW12 in complex with Dendrin PY motifs, we developed a potent peptide inhibitor capable of specifically blocking the binding between Kibra and Dendrin in neurons. Systematic administration of the inhibitory peptide attenuated excitatory synaptic transmission, completely blocked long-term potentiation induction, and impaired spatial learning and memory. A Kibra mutation found in Tourette syndrome patients causes defects in binding to Dendrin. Thus, Kibra can modulate spatial learning and memory via binding to Dendrin.
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Affiliation(s)
- Zeyang Ji
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Hao Li
- Department of Physiology, School of Basic Medicine and Tongji Medical College, Huazhong University of Science and Technology, Wuhan 4030030, China; The Institute for Brain Research, Collaborative Innovation Center for Brain Science, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Zhou Yang
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Xian Huang
- Department of Physiology, School of Basic Medicine and Tongji Medical College, Huazhong University of Science and Technology, Wuhan 4030030, China; The Institute for Brain Research, Collaborative Innovation Center for Brain Science, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Xiao Ke
- Department of Physiology, School of Basic Medicine and Tongji Medical College, Huazhong University of Science and Technology, Wuhan 4030030, China; The Institute for Brain Research, Collaborative Innovation Center for Brain Science, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Sehui Ma
- Department of Physiology, School of Basic Medicine and Tongji Medical College, Huazhong University of Science and Technology, Wuhan 4030030, China; The Institute for Brain Research, Collaborative Innovation Center for Brain Science, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Zhijie Lin
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
| | - Youming Lu
- Department of Physiology, School of Basic Medicine and Tongji Medical College, Huazhong University of Science and Technology, Wuhan 4030030, China; The Institute for Brain Research, Collaborative Innovation Center for Brain Science, Huazhong University of Science and Technology, Wuhan 430030, China.
| | - Mingjie Zhang
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China; Center of Systems Biology and Human Health, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
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14
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Kwok E, Rodriguez DJ, Kremerskothen J, Nyarko A. Intrinsic disorder and amino acid specificity modulate binding of the WW2 domain in kidney and brain protein (KIBRA) to synaptopodin. J Biol Chem 2019; 294:17383-17394. [PMID: 31597702 DOI: 10.1074/jbc.ra119.009589] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 10/07/2019] [Indexed: 01/19/2023] Open
Abstract
The second WW domain (WW2) of the kidney and brain scaffolding protein, KIBRA, has an isoleucine (Ile-81) rather than a second conserved tryptophan and is primarily unstructured. However, it adopts the canonical triple-stranded antiparallel β-sheet structure of WW domains when bound to a two-PPXY motif peptide of the synaptic protein Dendrin. Here, using a series of biophysical experiments, we demonstrate that the WW2 domain remains largely disordered when bound to a 69-residue two-PPXY motif polypeptide of the synaptic and podocyte protein synaptopodin (SYNPO). Isothermal titration calorimetry and CD experiments revealed that the interactions of the disordered WW2 domain with SYNPO are significantly weaker than SYNPO's interactions with the well-folded WW1 domain and that an I81W substitution in the WW2 domain neither enhances binding affinity nor induces substantial WW2 domain folding. In the tandem polypeptide, the two WW domains synergized, enhancing the overall binding affinity with the I81W variant tandem polypeptide 2-fold compared with the WT polypeptide. Solution NMR results showed that SYNPO binding induces small but definite chemical shift perturbations in the WW2 domain, confirming the disordered state of the WW2 domain in this complex. These analyses also disclosed that SYNPO binds the tandem WW domain polypeptide in an antiparallel manner, that is, the WW1 domain binds the second PPXY motif of SYNPO. We propose a binding model consisting of a bipartite interaction mode in which the largely disordered WW2 forms a "fuzzy" complex with SYNPO. This binding mode may be important for specific cellular functions.
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Affiliation(s)
- Ethiene Kwok
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331
| | - Diego J Rodriguez
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331
| | | | - Afua Nyarko
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331
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15
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Wang J, Hidaka T, Sasaki Y, Tanaka E, Takagi M, Shibata T, Kubo A, Trejo JAO, Wang L, Asanuma K, Tomino Y. Neurofilament heavy polypeptide protects against reduction in synaptopodin expression and prevents podocyte detachment. Sci Rep 2018; 8:17157. [PMID: 30464326 PMCID: PMC6249220 DOI: 10.1038/s41598-018-35465-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 10/31/2018] [Indexed: 11/17/2022] Open
Abstract
Podocytes are highly specialized cells that line the glomerulus of the kidney and play a role in filtration. Podocyte injury plays a critical role in the development of many kidney diseases, but the underlying mechanisms remain unclear. In this study, we identified that neurofilament heavy polypeptide (NEFH), an intermediate filament component, protects podocyte from injury. We observed that NEFH was upregulated after ADRIAMYCIN(ADR)-induced podocyte injury in both mice and cultured murine podocytes. Immunofluorescence and co-immunoprecipitation analyses revealed that NEFH was colocalized with synaptopodin, a podocyte-specific marker. High NEFH expression in podocytes prevented the Adriamycin-induced reduction in synaptopodin expression. The siRNA-mediated knockdown of NEFH in podocytes reduced the number of vinculin-containing focal contacts, thereby reducing adhesion to the extracellular matrix and increasing podocyte detachment. In addition, NEFH expression was significantly increased in renal biopsy specimens from patients with focal segmental glomerulosclerosis and membranous nephropathy, but in those with minimal change disease. These findings indicate that NEFH is expressed in podocytes during the disease course and that it prevents the reduction in synaptopodin expression and detachment of podocytes.
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Affiliation(s)
- Juan Wang
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo, 113-8421, Japan.,Department of Nephrology, the First Hospital of China Medical University, No.155 NanjingBei Street, Shenyang, Liaoning, 110001, China
| | - Teruo Hidaka
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Yu Sasaki
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Eriko Tanaka
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo, 113-8421, Japan.,Department of Pediatrics and Developmental Biology, Graduate School of Medicine, Tokyo Medical and Dental University, Yushima 1-5-45, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Miyuki Takagi
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Terumi Shibata
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Ayano Kubo
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Juan Alejandro Oliva Trejo
- Department of Cellular and Molecular Neuropathology, Juntendo University Graduate School of Medicine, Hongo 2-1-1, Bunkyo-Ku, Tokyo, 113-8421, Japan
| | - Lining Wang
- Department of Nephrology, the First Hospital of China Medical University, No.155 NanjingBei Street, Shenyang, Liaoning, 110001, China
| | - Katsuhiko Asanuma
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo, 113-8421, Japan. .,Department of Nephrology, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan.
| | - Yasuhiko Tomino
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo, 113-8421, Japan.,Asian Pacific Renal Research Promotion Office, Medical Cooporation SHOWAKAI, Tokyo, Japan
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16
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Mizdrak M, Vukojević K, Filipović N, Čapkun V, Benzon B, Durdov MG. Expression of DENDRIN in several glomerular diseases and correlation to pathological parameters and renal failure - preliminary study. Diagn Pathol 2018; 13:90. [PMID: 30458823 PMCID: PMC6247684 DOI: 10.1186/s13000-018-0767-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 11/07/2018] [Indexed: 01/19/2023] Open
Abstract
Background In glomerular injury dendrin translocates from the slit diaphragm to the podocyte nucleus, inducing apoptosis. We analyzed dendrin expression in IgA glomerulonephritis and Henoch Schönlein purpura (IgAN/HSP) versus in podocytopathies minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS), and compared it to pathohistological findings and renal function at the time of biopsy and the last follow-up. Methods Twenty males and 13 females with median of age 35 years (min-max: 3–76) who underwent percutaneous renal biopsy and had diagnosis of glomerular disease (GD) were included in this retrospective study. Fifteen patients had IgAN/HSP and eighteen podocytopathy. Control group consisted of ten patients who underwent nephrectomy due to renal cancer. Dendrin expression pattern (membranous, dual, nuclear or negative), number of dendrin positive nuclei and proportion of dendrin negative glomeruli were analyzed. Results In GD and the control group significant differences in number of dendrin positive nuclei and proportion of dendrin negative glomeruli were found (P = 0.004 and P = 0.003, respectively). Number of dendrin positive nuclei was higher in podocytopathies than in IgAN/HSP, 3.90 versus 1.67 (P = 0.028). Proportion of dendrin negative glomeruli correlated to higher rates of interstitial fibrosis (P = 0.038), tubular atrophy (P = 0.011) and globally sclerotic glomeruli (P = 0.008). Dual and nuclear dendrin expression pattern were connected with lower rate of interstitial fibrosis and tubular atrophy than negative dendrin expression pattern (P = 0.024 and P = 0.017, respectively). Proportion of dendrin negative glomeruli correlated with lower creatinine clearance (CC) at the time of biopsy and the last follow-up (P = 0.010 and P < 0.001, respectively). Dendrin expression pattern correlated to CC at the last follow-up (P = 0.009), being lower in patients with negative than nuclear or dual dendrin expression (P = 0.034 and P = 0.004, respectively). Conclusion In this pilot study the number of dendrin positive nuclei was higher in podocytopathies than in inflammatory GD. Negative dendrin expression pattern correlated to chronic tubulointerstitial changes and lower CC, which needs to be confirmed in a larger series.
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Affiliation(s)
- Maja Mizdrak
- Department of Nephrology and Hemodialysis, University Hospital Centre Split, Šoltanska 1, 21000, Split, Croatia.
| | - Katarina Vukojević
- Department of Anatomy, Histology and Embryology, University of Split School of Medicine, Split, Croatia
| | - Natalija Filipović
- Department of Anatomy, Histology and Embryology, University of Split School of Medicine, Split, Croatia
| | - Vesna Čapkun
- Department of Nuclear Medicine, University Hospital Centre Split, Split, Croatia
| | - Benjamin Benzon
- Department of Pathology, Forensic medicine and Cytology, University Hospital Centre Split, Split, Croatia.,University of Split School of Medicine, Split, Croatia
| | - Merica Glavina Durdov
- Department of Pathology, Forensic medicine and Cytology, University Hospital Centre Split, Split, Croatia.,University of Split School of Medicine, Split, Croatia
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17
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Empitu MA, Kadariswantiningsih IN, Aizawa M, Asanuma K. MAGI-2 and scaffold proteins in glomerulopathy. Am J Physiol Renal Physiol 2018; 315:F1336-F1344. [PMID: 30110567 DOI: 10.1152/ajprenal.00292.2018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
In many cells and tissues, including the glomerular filtration barrier, scaffold proteins are critical in optimizing signal transduction by enhancing structural stability and functionality of their ligands. Recently, mutations in scaffold protein membrane-associated guanylate kinase inverted 2 (MAGI-2) encoding gene were identified among the etiology of steroid-resistant nephrotic syndrome. MAGI-2 interacts with core proteins of multiple pathways, such as transforming growth factor-β signaling, planar cell polarity pathway, and Wnt/β-catenin signaling in podocyte and slit diaphragm. Through the interaction with its ligand, MAGI-2 modulates the regulation of apoptosis, cytoskeletal reorganization, and glomerular development. This review aims to summarize recent findings on the role of MAGI-2 and some other scaffold proteins, such as nephrin and synaptopodin, in the underlying mechanisms of glomerulopathy.
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Affiliation(s)
- Maulana A Empitu
- Department of Nephrology, Graduate School of Medicine, Chiba University , Chiba , Japan.,Department of Pharmacology and Therapeutics, Faculty of Medicine, Universitas Airlangga , Surabaya , Indonesia
| | - Ika N Kadariswantiningsih
- Department of Nephrology, Graduate School of Medicine, Chiba University , Chiba , Japan.,Department of Medical Microbiology, Faculty of Medicine, Universitas Airlangga , Surabaya , Indonesia
| | - Masashi Aizawa
- Department of Nephrology, Graduate School of Medicine, Chiba University , Chiba , Japan
| | - Katsuhiko Asanuma
- Department of Nephrology, Graduate School of Medicine, Chiba University , Chiba , Japan
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18
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Rac1 in podocytes promotes glomerular repair and limits the formation of sclerosis. Sci Rep 2018; 8:5061. [PMID: 29567961 PMCID: PMC5864960 DOI: 10.1038/s41598-018-23278-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 03/06/2018] [Indexed: 02/06/2023] Open
Abstract
Rac1, a Rho family member, is ubiquitously expressed and participates in various biological processes. Rac1 expression is induced early in podocyte injury, but its role in repair is unclear. To investigate the role of Rac1 expression in podocytes under pathological conditions, we used podocyte-specific Rac1 conditional knock-out (cKO) mice administered adriamycin (ADR), which causes nephrosis and glomerulosclerosis. Larger areas of detached podocytes, more adhesion of the GBM to Bowman’s capsule, and a higher ratio of sclerotic glomeruli were observed in Rac1 cKO mice than in control mice, whereas no differences were observed in glomerular podocyte numbers in both groups after ADR treatment. The mammalian target of rapamycin (mTOR) pathway, which regulates the cell size, was more strongly suppressed in the podocytes of Rac1 cKO mice than in those of control mice under pathological conditions. In accordance with this result, the volumes of podocytes in Rac1 cKO mice were significantly reduced compared with those of control mice. Experiments using in vitro ADR-administered Rac1 knockdown podocytes also supported that a reduction in Rac1 suppressed mTOR activity in injured podocytes. Taken together, these data indicate that Rac1-associated mTOR activation in podocytes plays an important role in preventing the kidneys from developing glomerulosclerosis.
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19
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Hosoe-Nagai Y, Hidaka T, Sonoda A, Sasaki Y, Yamamoto-Nonaka K, Seki T, Asao R, Tanaka E, Trejo JAO, Kodama F, Takagi M, Tada N, Ueno T, Nishinakamura R, Tomino Y, Asanuma K. Re-expression of Sall1 in podocytes protects against adriamycin-induced nephrosis. J Transl Med 2017; 97:1306-1320. [PMID: 28759006 DOI: 10.1038/labinvest.2017.69] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 04/26/2017] [Accepted: 05/01/2017] [Indexed: 12/12/2022] Open
Abstract
The highly conserved spalt (sal) gene family members encode proteins characterized by multiple double zinc finger motifs of the C2H2 type. Humans and mice each have four known Sal-like genes (SALL1-4 in humans and Sall1-4 in mice). Sall1 is known to have a crucial role in kidney development. To explore the significance of Sall1 in differentiated podocytes, we investigated podocyte-specific Sall1-deficient mice (Sall1 KOp°d°/p°d°) using a podocin-Cre/loxP system and siRNA Sall1 knockdown (Sall1 KD) podocytes. Under physiological conditions, Sall1 KOp°d°/p°d° mice exhibited no proteinuria during their lifetime, but foot-process effacement was detected in some of the podocytes. To elucidate the role of Sall1 in injured podocytes, we used an adriamycin (ADR)-induced model of nephrosis and glomerulosclerosis. Surprisingly, the expression of Sall1 was elevated in control mice on day 14 after ADR injection. On day 28 after ADR injection, Sall1 KOp°d°/p°d° mice exhibited significantly higher levels of proteinuria and higher numbers of sclerotic glomeruli. Differentiated Sall1 KD podocytes showed a loss of synaptopodin, suppressed stress fiber formation, and, ultimately, impaired directed cell migration. In addition, the loss of Sall1 increased the number of apoptotic podocytes following ADR treatment. These results indicated that Sall1 has a protective role in podocytes; thus, we investigated the endoplasmic reticulum stress marker GRP78. GRP78 expression was higher in ADR-treated Sall1 KOp°d°/p°d° mice than in control mice. Sall1 appeared to influence the expression of GRP78 in injured podocytes. These results suggest that Sall1 is associated with actin reorganization, endoplasmic reticulum stress, and apoptosis in injured podocytes. These protective aspects of Sall1 re-expression in injured podocytes may have the potential to reduce apoptosis and possibly glomerulosclerosis.
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Affiliation(s)
- Yoshiko Hosoe-Nagai
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Teruo Hidaka
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Ayano Sonoda
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Yu Sasaki
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Kanae Yamamoto-Nonaka
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan.,Laboratory for Kidney Research (TMK project), Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Takuto Seki
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan.,Laboratory for Kidney Research (TMK project), Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Rin Asao
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan.,Laboratory for Kidney Research (TMK project), Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Eriko Tanaka
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan.,Department of Pediatrics, Tokyo Medical and Dental University, Tokyo, Japan
| | - Juan Alejandro Oliva Trejo
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan.,Laboratory for Kidney Research (TMK project), Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan.,Department of Cellular and Molecular Neuropathology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Fumiko Kodama
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Miyuki Takagi
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Nobuhiro Tada
- Atopy Research Center, Juntendo University School of Medicine, Tokyo, Japan
| | - Takashi Ueno
- Laboratory of Proteomics and Medical Science, Research Support Center, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Ryuichi Nishinakamura
- Department of Kidney Development, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
| | - Yasuhiko Tomino
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Katsuhiko Asanuma
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan.,Laboratory for Kidney Research (TMK project), Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
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20
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Lin T, Zhang L, Liu S, Chen Y, Zhang H, Zhao X, Li R, Zhang Q, Liao R, Huang Z, Zhang B, Wang W, Liang X, Shi W. WWC1 promotes podocyte survival via stabilizing slit diaphragm protein dendrin. Mol Med Rep 2017; 16:8685-8690. [PMID: 28990091 PMCID: PMC5779946 DOI: 10.3892/mmr.2017.7708] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 08/07/2017] [Indexed: 02/06/2023] Open
Abstract
Previous studies have indicated that glomerular podocyte injury serves a crucial role in proteinuria during the process of chronic kidney disease. The slit diaphragm of podocytes forms the final barrier to proteinuria. Dendrin, a constituent of the slit diaphragm protein complex, has been observed to relocate from the slit diaphragm to the nuclei in injured podocytes and promote podocyte apoptosis. However, the exact mechanism for nuclear relocation of dendrin remains unclear. The expression of WWC1 in podocyte injury induced by lipopolysaccharides (LPS) or adriamycin (ADR) was detected by reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR), western blotting and the immunofluorescence assay. The role of WWC1 in podocyte apoptosis was detected by knockdown of WWC1 and flow cytometry. The mRNA and protein expression levels of apoptosis‑associated genes Bcl‑2‑associated X (Bax) and Bcl‑2 were measured by RT‑qPCR and western blotting. The impact of WWC1 on dendrin nucleus relocation in vitro in podocytes was further evaluated by knockdown of WWC1. Expression of WWC1 significantly decreased in injured podocytes in vitro. The loss‑of‑function assay indicated that knockdown of WWC1 gene in vitro promoted podocyte apoptosis, accompanied with increased levels of the pro‑apoptotic protein Bax and decreased levels of the anti‑apoptotic protein Bcl‑2. Furthermore, the relocation of dendrin protein was significantly promoted by knockdown of the WWC1 gene. In conclusion, the study indicated that loss of WWC1 may contribute to podocyte apoptosis by inducing nuclear relocation of dendrin protein, which provided novel insight into the molecular events in podocyte apoptosis.
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Affiliation(s)
- Ting Lin
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
| | - Li Zhang
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
| | - Shuangxin Liu
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
| | - Yuanhan Chen
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
| | - Hong Zhang
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
| | - Xingchen Zhao
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
| | - Ruizhao Li
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
| | - Qianmei Zhang
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
| | - Ruyi Liao
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
| | - Zongshun Huang
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
| | - Bin Zhang
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
| | - Wenjian Wang
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
| | - Xinling Liang
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
| | - Wei Shi
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
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21
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Shirata N, Ihara KI, Yamamoto-Nonaka K, Seki T, Makino SI, Oliva Trejo JA, Miyake T, Yamada H, Campbell KN, Nakagawa T, Mori K, Yanagita M, Mundel P, Nishimori K, Asanuma K. Glomerulosclerosis Induced by Deficiency of Membrane-Associated Guanylate Kinase Inverted 2 in Kidney Podocytes. J Am Soc Nephrol 2017; 28:2654-2669. [PMID: 28539383 DOI: 10.1681/asn.2016121356] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 04/03/2017] [Indexed: 11/03/2022] Open
Abstract
Membrane-associated guanylate kinase inverted 2 (MAGI-2) is a component of the slit diaphragm (SD) of glomerular podocytes. Here, we investigated the podocyte-specific function of MAGI-2 using newly generated podocyte-specific MAGI-2-knockout (MAGI-2-KO) mice. Compared with podocytes from wild-type mice, podocytes from MAGI-2-KO mice exhibited SD disruption, morphologic abnormalities of foot processes, and podocyte apoptosis leading to podocyte loss. These pathologic changes manifested as massive albuminuria by 8 weeks of age and glomerulosclerosis and significantly higher plasma creatinine levels at 12 weeks of age; all MAGI-2-KO mice died by 20 weeks of age. Loss of MAGI-2 in podocytes associated with decreased expression and nuclear translocation of dendrin, which is also a component of the SD complex. Dendrin translocates from the SD to the nucleus of injured podocytes, promoting apoptosis. Our coimmunoprecipitation and in vitro reconstitution studies showed that dendrin is phosphorylated by Fyn and dephosphorylated by PTP1B, and that Fyn-induced phosphorylation prevents Nedd4-2-mediated ubiquitination of dendrin. Under physiologic conditions in vivo, phosphorylated dendrin localized at the SDs; in the absence of MAGI-2, dephosphorylated dendrin accumulated in the nucleus. Furthermore, induction of experimental GN in rats led to the downregulation of MAGI-2 expression and the nuclear accumulation of dendrin in podocytes. In summary, MAGI-2 and Fyn protect dendrin from Nedd4-2-mediated ubiquitination and from nuclear translocation, thereby maintaining the physiologic homeostasis of podocytes, and the lack of MAGI-2 in podocytes results in FSGS.
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Affiliation(s)
- Naritoshi Shirata
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan.,Sohyaku, Innovative Research Division, Mitsubishi Tanabe Pharmaceutical Corporation, Toda, Japan
| | - Kan-Ichiro Ihara
- The Laboratory of Molecular Biology, Department of Molecular and Cell Biology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Kanae Yamamoto-Nonaka
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan.,Division of Nephrology, Department of Internal Medicine, Faculty of Medicine, Juntendo University, Tokyo, Japan
| | - Takuto Seki
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan.,Division of Nephrology, Department of Internal Medicine, Faculty of Medicine, Juntendo University, Tokyo, Japan
| | - Shin-Ichi Makino
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan.,Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Juan Alejandro Oliva Trejo
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Takafumi Miyake
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan.,Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Hiroyuki Yamada
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan.,Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Kirk Nicholas Campbell
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York; and
| | - Takahiko Nakagawa
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Kiyoshi Mori
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Motoko Yanagita
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan.,Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Peter Mundel
- Department of Medicine, Harvard Medical School, Massachusetts General Hospital, Boston, Massachusetts
| | - Katsuhiko Nishimori
- The Laboratory of Molecular Biology, Department of Molecular and Cell Biology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Katsuhiko Asanuma
- The Laboratory for Kidney Research (TMK project), Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan; .,Division of Nephrology, Department of Internal Medicine, Faculty of Medicine, Juntendo University, Tokyo, Japan.,Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
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22
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Sorting Nexin 9 facilitates podocin endocytosis in the injured podocyte. Sci Rep 2017; 7:43921. [PMID: 28266622 PMCID: PMC5339724 DOI: 10.1038/srep43921] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 02/01/2017] [Indexed: 12/18/2022] Open
Abstract
The irreversibility of glomerulosclerotic changes depends on the degree of podocyte injury. We have previously demonstrated the endocytic translocation of podocin to the subcellular area in severely injured podocytes and found that this process is the primary disease trigger. Here we identified the protein sorting nexin 9 (SNX9) as a novel facilitator of podocin endocytosis in a yeast two-hybrid analysis. SNX9 is involved in clathrin-mediated endocytosis, actin rearrangement and vesicle transport regulation. Our results revealed and confirmed that SNX9 interacts with podocin exclusively through the Bin–Amphiphysin–Rvs (BAR) domain of SNX9. Immunofluorescence staining revealed the expression of SNX9 in response to podocyte adriamycin-induced injury both in vitro and in vivo. Finally, an analysis of human glomerular disease biopsy samples demonstrated strong SNX9 expression and co-localization with podocin in samples representative of severe podocyte injury, such as IgA nephropathy with poor prognosis, membranous nephropathy and focal segmental glomerulosclerosis. In conclusion, we identified SNX9 as a facilitator of podocin endocytosis in severe podocyte injury and demonstrated the expression of SNX9 in the podocytes of both nephropathy model mice and human patients with irreversible glomerular disease.
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23
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Yamamoto-Nonaka K, Koike M, Asanuma K, Takagi M, Oliva Trejo JA, Seki T, Hidaka T, Ichimura K, Sakai T, Tada N, Ueno T, Uchiyama Y, Tomino Y. Cathepsin D in Podocytes Is Important in the Pathogenesis of Proteinuria and CKD. J Am Soc Nephrol 2016; 27:2685-700. [PMID: 26823550 DOI: 10.1681/asn.2015040366] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 11/30/2015] [Indexed: 12/24/2022] Open
Abstract
Studies have revealed many analogies between podocytes and neurons, and these analogies may be key to elucidating the pathogenesis of podocyte injury. Cathepsin D (CD) is a representative aspartic proteinase in lysosomes. Central nervous system neurons in CD-deficient mice exhibit a form of lysosomal storage disease with a phenotype resembling neuronal ceroid lipofuscinoses. In the kidney, the role of CD in podocytes has not been fully explored. Herein, we generated podocyte-specific CD-knockout mice that developed proteinuria at 5 months of age and ESRD by 20-22 months of age. Immunohistochemical analysis of these mice showed apoptotic podocyte death followed by proteinuria and glomerulosclerosis with aging. Using electron microscopy, we identified, in podocytes, granular osmiophilic deposits (GRODs), autophagosome/autolysosome-like bodies, and fingerprint profiles, typical hallmarks of CD-deficient neurons. CD deficiency in podocytes also led to the cessation of autolysosomal degradation and accumulation of proteins indicative of autophagy impairment and the mitochondrial ATP synthase subunit c accumulation in the GRODs, again similar to changes reported in CD-deficient neurons. Furthermore, both podocin and nephrin, two essential components of the slit diaphragm, translocated to Rab7- and lysosome-associated membrane glycoprotein 1-positive amphisomes/autolysosomes that accumulated in podocyte cell bodies in podocyte-specific CD-knockout mice. We hypothesize that defective lysosomal activity resulting in foot process effacement caused this accumulation of podocin and nephrin. Overall, our results suggest that loss of CD in podocytes causes autophagy impairment, triggering the accumulation of toxic subunit c-positive lipofuscins as well as slit diaphragm proteins followed by apoptotic cell death.
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Affiliation(s)
- Kanae Yamamoto-Nonaka
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan
| | | | - Katsuhiko Asanuma
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan; TMK Project, Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Miyuki Takagi
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan
| | | | - Takuto Seki
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Teruo Hidaka
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan
| | | | | | - Norihiro Tada
- Division of Genome Research, Research Institute for Diseases of Old Ages
| | - Takashi Ueno
- Laboratory of Proteomics and Biomolecular Science, Research Support Center
| | - Yasuo Uchiyama
- Department of Cellular and Molecular Neuropathology, Juntendo University Graduate School of Medicine, Tokyo, Japan; and
| | - Yasuhiko Tomino
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan;
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24
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Taneda S, Honda K, Ohno M, Uchida K, Nitta K, Oda H. Podocyte and endothelial injury in focal segmental glomerulosclerosis: an ultrastructural analysis. Virchows Arch 2015; 467:449-58. [PMID: 26266776 PMCID: PMC4609310 DOI: 10.1007/s00428-015-1821-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 07/06/2015] [Accepted: 08/04/2015] [Indexed: 11/15/2022]
Abstract
Podocyte injury contributes to the development of focal segmental glomerulosclerosis (FSGS). Endocapillary hypercellularity, which is one of the pathological characteristics of FSGS, suggests that glomerular endothelial injury may also be involved in the pathogenesis of FSGS. In electron micrographs of patients with FSGS (n = 43), we conducted morphometric measurements of foot process width (FPW) and podocyte detachment (PD) as markers of podocyte injury and subendothelial widening (SW) of the glomerular basement membrane as a marker of endothelial injury and compared them to those in patients with minimal change nephrotic syndrome (MCNS; n = 11) and control kidney donors (n = 5). Associations between ultrastructural and clinical parameters were analyzed according to the FSGS variants defined by the Columbia classification. FPW was significantly higher in the FSGS group than that in the MCNS and control groups, particularly in the collapsing, tip, and cellular variants of FSGS. Percentage of glomerular basement membrane (GBM) length showing PD and SW was significantly increased in the FSGS group, especially in the collapsing, cellular, and not otherwise specified variants. In FSGS, FPW was inversely correlated with disease duration, but not with proteinuria. Finally, the percentage of GBM length with SW significantly correlated with clinical parameters indicative of poor prognosis, such as lower remission rate and lower estimated glomerular filtration rate at the final observation. Quantitative measurement of podocyte and endothelial injury by electron microscopy might be useful for evaluating histological activity and predicting prognosis in FSGS.
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Affiliation(s)
- Sekiko Taneda
- Department of Pathology, Tokyo Women's Medical University, Tokyo, Japan.
| | - Kazuho Honda
- Department of Pathology, Tokyo Women's Medical University, Tokyo, Japan.,Department of Anatomy, School of Medicine, Showa University, Tokyo, Japan
| | - Mayuko Ohno
- Department of Pathology, Tokyo Women's Medical University, Tokyo, Japan
| | - Keiko Uchida
- Department of Internal Medicine, Kidney Center, Tokyo Women's Medical University, Tokyo, Japan
| | - Kosaku Nitta
- Department of Internal Medicine, Kidney Center, Tokyo Women's Medical University, Tokyo, Japan
| | - Hideaki Oda
- Department of Pathology, Tokyo Women's Medical University, Tokyo, Japan
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25
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Weins A, Wong JS, Basgen JM, Gupta R, Daehn I, Casagrande L, Lessman D, Schwartzman M, Meliambro K, Patrakka J, Shaw A, Tryggvason K, He JC, Nicholas SB, Mundel P, Campbell KN. Dendrin ablation prolongs life span by delaying kidney failure. THE AMERICAN JOURNAL OF PATHOLOGY 2015; 185:2143-57. [PMID: 26073036 DOI: 10.1016/j.ajpath.2015.04.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2014] [Revised: 04/01/2015] [Accepted: 04/21/2015] [Indexed: 12/16/2022]
Abstract
Podocyte loss is central to the progression of proteinuric kidney diseases leading to end-stage kidney disease (ESKD), requiring renal replacement therapy, such as dialysis. Despite modern tools and techniques, the 5-year mortality of some patients requiring dialysis remains at about 70% to 80%. Thus, there is a great unmet need for podocyte-specific treatments aimed at preventing podocyte loss and the ensuing development of ESKD. Here, we show that ablation of the podocyte death-promoting protein dendrin delays the onset of ESKD, thereby expanding the life span of mice lacking the adapter protein CD2AP. Ablation of dendrin delays onset and severity of proteinuria and podocyte loss. In addition, dendrin ablation ameliorates mesangial volume expansion and up-regulation of mesangial fibronectin expression, which is mediated by a podocyte-secreted factor. In conclusion, onset of ESKD and death can be markedly delayed by blocking the function of dendrin.
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Affiliation(s)
- Astrid Weins
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts; Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Jenny S Wong
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - John M Basgen
- Department of Research, Morphometry and Stereology Laboratory, Charles R. Drew University of Medicine and Science, Los Angeles, California
| | - Ritu Gupta
- Department of Pathology, Albert Einstein College of Medicine, Medicine, Bronx, New York
| | - Ilse Daehn
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Lisette Casagrande
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - David Lessman
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Monica Schwartzman
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Kristin Meliambro
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Jaakko Patrakka
- KI/AZ Integrated CardioMetabolic Center (ICMC), Department of Medicine, Karolinska Institute at Karolinska University Hospital Huddinge, Stockholm, Sweden
| | - Andrey Shaw
- Division of Immunobiology, Washington University School of Medicine, St. Louis, Missouri
| | - Karl Tryggvason
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
| | - John Cijiang He
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Susanne B Nicholas
- Division of Nephrology, University of California Los Angeles, Los Angeles, California
| | - Peter Mundel
- Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Kirk N Campbell
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York.
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26
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Schwartzman M, Reginensi A, Wong JS, Basgen JM, Meliambro K, Nicholas SB, D'Agati V, McNeill H, Campbell KN. Podocyte-Specific Deletion of Yes-Associated Protein Causes FSGS and Progressive Renal Failure. J Am Soc Nephrol 2015; 27:216-26. [PMID: 26015453 DOI: 10.1681/asn.2014090916] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 04/02/2015] [Indexed: 11/03/2022] Open
Abstract
FSGS is the most common primary glomerular disease underlying ESRD in the United States and is increasing in incidence globally. FSGS results from podocyte injury, yet the mechanistic details of disease pathogenesis remain unclear. This has resulted in an unmet clinical need for cell-specific therapy in the treatment of FSGS and other proteinuric kidney diseases. We previously identified Yes-associated protein (YAP) as a prosurvival signaling molecule, the in vitro silencing of which increases podocyte susceptibility to apoptotic stimulus. YAP is a potent oncogene that is a prominent target for chemotherapeutic drug development. In this study, we tested the hypothesis that podocyte-specific deletion of Yap leads to proteinuric kidney disease through increased podocyte apoptosis. Yap was selectively silenced in podocytes using Cre-mediated recombination controlled by the podocin promoter. Yap silencing in podocytes resulted in podocyte apoptosis, podocyte depletion, proteinuria, and an increase in serum creatinine. Histologically, features characteristic of FSGS, including mesangial sclerosis, podocyte foot process effacement, tubular atrophy, interstitial fibrosis, and casts, were observed. In human primary FSGS, we noted reduced glomerular expression of YAP. Taken together, these results suggest a role for YAP as a physiologic antagonist of podocyte apoptosis, the signaling of which is essential for maintaining the integrity of the glomerular filtration barrier. These data suggest potential nephrotoxicity with strategies directed toward inhibition of YAP function. Further studies should evaluate the role of YAP in proteinuric glomerular disease pathogenesis and its potential utility as a therapeutic target.
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Affiliation(s)
- Monica Schwartzman
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Antoine Reginensi
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Jenny S Wong
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - John M Basgen
- Department of Research, Morphometry and Stereology Laboratory, Charles R. Drew University of Medicine and Science, Los Angeles, California
| | - Kristin Meliambro
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Susanne B Nicholas
- Department of Research, Morphometry and Stereology Laboratory, Charles R. Drew University of Medicine and Science, Los Angeles, California; Department of Medicine, Division of Nephrology, University of California Los Angeles, Los Angeles, California; and
| | - Vivette D'Agati
- Department of Pathology, Columbia University College of Physicians and Surgeons, New York, New York
| | - Helen McNeill
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Kirk N Campbell
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York;
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27
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Jeong KH, Asanuma K, Lydia A, Takagi M, Asao R, Kodama F, Asanuma E, Tomino Y. Combination therapy with telmisartan and oxacalcitriol suppresses the progression of murine adriamycin nephropathy. Nephron Clin Pract 2015; 129:143-54. [PMID: 25661164 DOI: 10.1159/000369346] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Accepted: 10/27/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Blockade of the renin-angiotensin system plays a key role in suppressing the progression of renal diseases. It has not been well established whether this therapy provides additional effects when combined with vitamin D or its analog in a model of adriamycin (ADR)-induced nephropathy. METHODS We evaluated the effect of an angiotensin II subtype 1 receptor blocker (telmisartan) combined with a vitamin D analog (oxacalcitriol) on mice ADR-induced nephropathy (9.5 mg/kg single intravenous injection). We also tested immortalized murine podocytes to examine the effects on podocyte apoptosis. RESULTS Mice with ADR-induced nephropathy developed progressive albuminuria and glomerulosclerosis within 30 days accompanied by decreased expression of slit diaphragm (SD)-associated proteins (nephrin and podocin), reduced numbers of podocytes, and increased systolic blood pressure. Treatment with telmisartan or oxacalcitriol alone moderately ameliorated kidney injury. The combined treatment most effectively reduced the albuminuria and glomerulosclerosis. These effects were accompanied by the restoration of SD-associated proteins, reduction of podocyte apoptosis, and prevention of podocyte depletion in the glomeruli. Treatment with telmisartan, oxacalcitriol, and the combination therapy resulted in similar reductions in systolic blood pressure. In cultured murine podocytes, ADR stimulated the expression of Bax/Bcl-2 and apoptosis as determined by Hoechst 33342 staining. These changes were effectively inhibited by telmisartan or oxacalcitriol, but the combination treatment most effectively reduced these effects. CONCLUSIONS These data demonstrated that application of a renin-angiotensin system blocker plus a vitamin D analog effectively prevented renal injury in ADR-induced nephropathy. The observed amelioration of renal injury may be partly attributable to antiapoptotic effects in podocytes.
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Affiliation(s)
- Kyung Hwan Jeong
- Division of Nephrology, Department of Internal Medicine, Faculty of Medicine, Juntendo University, Tokyo, Japan
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28
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Ihara KI, Asanuma K, Fukuda T, Ohwada S, Yoshida M, Nishimori K. MAGI-2 is critical for the formation and maintenance of the glomerular filtration barrier in mouse kidney. THE AMERICAN JOURNAL OF PATHOLOGY 2014; 184:2699-708. [PMID: 25108225 DOI: 10.1016/j.ajpath.2014.06.019] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Revised: 05/29/2014] [Accepted: 06/26/2014] [Indexed: 11/20/2022]
Abstract
Membrane-associated guanylate kinase inverted 2 (MAGI-2) is a tight junction protein in epithelial tissues. We previously reported the detailed expression patterns of MAGI-2 in mouse tissues, including kidney podocytes, based on results obtained from Venus knock-in mice for Magi2 locus. In the present study, homozygous deletion of the Magi2 gene in mice caused neonatal lethality, which was explained by podocyte morphological abnormalities and anuria. Immunohistological analysis showed that loss of MAGI-2 function induced a significant decrease in nephrin and dendrin at the slit diaphragm of the kidney, although other components of the slit diaphragm were unchanged. Furthermore, nuclear translocation of dendrin was observed in the podocytes of the MAGI-2-null mutants, along with enhanced expression of cathepsin L, which is reported to be critical for rearrangement of the actin cytoskeleton in podocytes. Expression analysis of the null mutants showed that loss of MAGI-2 function induces abnormal expression of various types of adhesion-related molecules. The present study is the first to demonstrate that MAGI-2 has a critical role in maintaining the functional structure of the slit diaphragm and that this molecule has an essential role in the functioning of the kidney filtration barrier.
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Affiliation(s)
- Kan-Ichiro Ihara
- Laboratory of Molecular Biology, Department of Molecular and Cell Biology, Graduate School of Agricultural Science, Tohoku University, Sendai
| | - Katsuhiko Asanuma
- Division of Nephrology, Department of Internal Medicine, Juntendo University School of Medicine, Tokyo; Laboratory for Kidney Research, Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto
| | - Tomokazu Fukuda
- Laboratory of Animal Breeding and Genetics, Department of Animal Biology, Graduate School of Agricultural Science, Tohoku University, Sendai
| | - Shyuichi Ohwada
- Laboratory of Functional Morphology, Department of Animal Biology, Graduate School of Agricultural Science, Tohoku University, Sendai
| | - Midori Yoshida
- Division of Pathology, National Institute of Health Sciences, Tokyo, Japan
| | - Katsuhiko Nishimori
- Laboratory of Molecular Biology, Department of Molecular and Cell Biology, Graduate School of Agricultural Science, Tohoku University, Sendai.
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29
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Notch2 activation ameliorates nephrosis. Nat Commun 2014; 5:3296. [DOI: 10.1038/ncomms4296] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 01/22/2014] [Indexed: 12/16/2022] Open
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Okamoto T, Sasaki S, Yamazaki T, Sato Y, Ito H, Ariga T. Prevalence of CD44-Positive Glomerular Parietal Epithelial Cells Reflects Podocyte Injury in Adriamycin Nephropathy. ACTA ACUST UNITED AC 2014; 124:11-8. [DOI: 10.1159/000357356] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Accepted: 11/15/2013] [Indexed: 11/19/2022]
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Campbell KN, Wong JS, Gupta R, Asanuma K, Sudol M, He JC, Mundel P. Yes-associated protein (YAP) promotes cell survival by inhibiting proapoptotic dendrin signaling. J Biol Chem 2013; 288:17057-62. [PMID: 23667252 DOI: 10.1074/jbc.c113.457390] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Kidney podocytes are highly specialized terminally differentiated cells that form the final barrier to urinary protein loss. Podocytes are a target for injury by metabolic, autoimmune, hereditary, inflammatory, and other stressors. Persistence of podocyte injury leads to podocyte death and loss, which results in progressive kidney damage and ultimately kidney failure. Dendrin is a dual compartment protein with proapoptotic signaling properties. Nuclear relocation of dendrin in response to glomerular injury promotes podocyte apoptosis. Here we show that Yes-associated protein (YAP), a downstream target of Hippo kinases and an inhibitor of apoptosis, is expressed in the nucleus of podocytes. The WW domains of YAP mediate the interaction with the PPXY motifs of dendrin. This interaction is functionally relevant because YAP binding to dendrin reduces dendrin-dependent, staurosporine-induced apoptosis in co-transfected HEK293 cells. Moreover gene silencing of YAP in podocytes increases adriamycin-induced podocyte apoptosis. It also increases staurosporine-induced caspase-3/7 activity, which is rescued by dendrin depletion in YAP knockdown cells. Our findings elucidate YAP binding to dendrin as a prosurvival mechanism. The antiapoptotic signaling properties of YAP in podocytes could hold significance in the quest for targeted therapeutics aimed at preventing podocyte loss.
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Affiliation(s)
- Kirk N Campbell
- Division of Nephrology, Mount Sinai School of Medicine, New York, New York 10029, USA.
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Kodama F, Asanuma K, Takagi M, Hidaka T, Asanuma E, Fukuda H, Seki T, Takeda Y, Hosoe-Nagai Y, Asao R, Horikoshi S, Tomino Y. Translocation of dendrin to the podocyte nucleus in acute glomerular injury in patients with IgA nephropathy. Nephrol Dial Transplant 2012; 28:1762-72. [PMID: 23143340 DOI: 10.1093/ndt/gfs500] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND It has been reported that podocytopenia has been occurring with increasing disease severity in patients with IgA nephropathy (IgAN). Dendrin is localized at the slit diaphragm (SD) in podocytes. We showed that dendrin translocates to the nucleus of injured podocytes in experimental nephritis and the nuclear dendrin promotes podocyte apoptosis. It is still unknown whether dendrin translocates from the SD to podocyte nucleus in IgAN. We investigated the presence of nuclear dendrin in patients with IgAN and the association between the translocated dendrin to the podocyte nucleus and disease activity. METHODS Fourteen adult patients with IgAN were enrolled. The pathological parameters were analyzed. Immunostaining of renal biopsy specimens and urinary sediments from IgAN or minimal change nephrotic syndrome (MCNS) as the control was performed. RESULTS A positive correlation was observed between an acute extracapillary change and the number of dendrin-positive nuclei. The location of dendrin in the nuclei was found in urinary podocytes of IgAN. The number of dendrin-positive nuclei in urinary podocytes of IgAN was significantly higher than that of MCNS. Urinary podocytes, which expressed the apoptosis marker annexin V, were also detected in IgAN. The translocation of dendrin to the podocyte nucleus as well as strong cathepsin L staining were detected in the glomeruli of IgAN. CONCLUSION An increasing number of dendrin-positive nuclei in the glomeruli suggest acute glomerular injury in IgAN. Apoptotic podocytes were detectable in the urine of IgAN. It appears that the translocation of dendrin to the podocyte nuclei enhances podocyte apoptosis in acute glomerular injury and leads to podocytopenia in patients with IgAN.
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Affiliation(s)
- Fumiko Kodama
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan
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Asao R, Asanuma K, Kodama F, Akiba-Takagi M, Nagai-Hosoe Y, Seki T, Takeda Y, Ohsawa I, Mano S, Matsuoka K, Kurosawa H, Ogasawara S, Hirayama Y, Sekine S, Horikoshi S, Hara M, Tomino Y. Relationships between levels of urinary podocalyxin, number of urinary podocytes, and histologic injury in adult patients with IgA nephropathy. Clin J Am Soc Nephrol 2012; 7:1385-93. [PMID: 22700887 DOI: 10.2215/cjn.08110811] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES Podocalyxin (PCX) is present on the apical cell membrane of podocytes and is shed in urine from injured podocytes. Urinary podocalyxin (u-PCX) is associated with severity of active glomerular injury in patients with glomerular diseases. This study examined the relationship between number of urinary podocytes, levels of u-PCX, and glomerular injury in adults with IgA nephropathy (IgAN). DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Urine samples voided in the morning on the day of biopsy were obtained from 51 patients with IgAN (18 men and 33 women; mean age, 31 years). All renal biopsy specimens were analyzed histologically. Pathologic variables of IgAN were analyzed per Shigematsu classification, the Oxford classification of IgAN, and the Clinical Guidelines of IgAN in Japan. Levels of u-PCX were measured by sandwich ELISA. RESULTS Histologic analysis based on Shigematsu classification revealed a significant correlation between levels of u-PCX and severity of acute extracapillary abnormalities (r=0.72; P<0.001), but levels of urinary protein excretion did not correlate with acute glomerular abnormalities. Levels of urinary protein excretion in patients with segmental sclerosis (n=19) were higher than in patients without (n=22) (0.49 [interquartile range (IQR), 0.20-0.88] g/g creatinine versus 0.20 [IQR, 0.10-0.33] g/g creatinine; P<0.01). The number of urinary podocytes in patients with segmental sclerosis was higher than in patients without (1.05 [IQR, 0.41-1.67] per mg creatinine versus 0.28 [IQR, 0.10-0.66] per mg creatinine; P<0.01). CONCLUSIONS Levels of u-PCX and the number of urinary podocytes are associated with histologic abnormalities in adults with IgAN.
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Affiliation(s)
- Rin Asao
- Division of Nephrology, Juntendo University Faculty of Medicine, Tokyo, Japan
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Asanuma K, Hidaka T, Tomino Y. [The cutting-edge of medicine; the role of podocytes in renal diseases]. NIHON NAIKA GAKKAI ZASSHI. THE JOURNAL OF THE JAPANESE SOCIETY OF INTERNAL MEDICINE 2012; 101:1092-101. [PMID: 22730741 DOI: 10.2169/naika.101.1092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Katsuhiko Asanuma
- Division of Nephrology, Juntendo University Graduate School of Medicine, Japan
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Lydia A, Asanuma K, Nonaka K, Takagi M, Jeong KH, Kodama F, Asao R, Asanuma E, Prodjosudjadi W, Tomino Y. Effects of 22-oxa-calcitriol on podocyte injury in adriamycin-induced nephrosis. Am J Nephrol 2011; 35:58-68. [PMID: 22189044 DOI: 10.1159/000334626] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Accepted: 10/24/2011] [Indexed: 12/11/2022]
Abstract
BACKGROUND In various animal studies, vitamin D has been shown to have a significant effect on reduction of proteinuria and the progression of kidney disease. However, little is known on its renoprotective effect in adriamycin (ADR)-induced nephrosis mice. The present study was intended to determine the therapeutic benefit of 22-oxa-calcitriol (OCT), a vitamin D analog, in reducing proteinuria and its renoprotective effect, i.e. preventing podocyte injury on ADR-induced nephrosis mice. METHODS Three experimental groups were used as follows: (1) nephrosis mice, established by a single intravenous injection of ADR; (2) ADR+OCT mice, nephrosis mice treated with OCT, and (3) mice treated only with OCT as the control group. Podocyte injury was assessed by podocyte apoptosis using the TUNEL assay, podocyte counting, podocyte-specific expressed protein by immunofluorescence and Western blot analysis, and foot process effacement using electron microscopy. RESULTS Lower proteinuria was observed in ADR+OCT mice. Improvement in glomerulosclerosis and interstitial fibrosis, and prevention of glomerular hyperfiltration were observed in ADR+OCT mice. Immunofluorescence and Western blot analyses showed restoration of downregulated expression of nephrin, CD2AP and podocin. Nevertheless, dendrin expression was not restored. An insignificant reduction in podocyte numbers was found in ADR+OCT mice. Complete foot process effacement was partially prevented in ADR+OCT mice. CONCLUSIONS The results indicate that OCT reduces podocyte injury and has renoprotective effects in ADR nephrosis mice.
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Affiliation(s)
- Aida Lydia
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan
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Yaddanapudi S, Altintas MM, Kistler AD, Fernandez I, Möller CC, Wei C, Peev V, Flesche JB, Forst AL, Li J, Patrakka J, Xiao Z, Grahammer F, Schiffer M, Lohmüller T, Reinheckel T, Gu C, Huber TB, Ju W, Bitzer M, Rastaldi MP, Ruiz P, Tryggvason K, Shaw AS, Faul C, Sever S, Reiser J. CD2AP in mouse and human podocytes controls a proteolytic program that regulates cytoskeletal structure and cellular survival. J Clin Invest 2011; 121:3965-80. [PMID: 21911934 DOI: 10.1172/jci58552] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2011] [Accepted: 07/20/2011] [Indexed: 12/11/2022] Open
Abstract
Kidney podocytes are highly differentiated epithelial cells that form interdigitating foot processes with bridging slit diaphragms (SDs) that regulate renal ultrafiltration. Podocyte injury results in proteinuric kidney disease, and genetic deletion of SD-associated CD2-associated protein (CD2AP) leads to progressive renal failure in mice and humans. Here, we have shown that CD2AP regulates the TGF-β1-dependent translocation of dendrin from the SD to the nucleus. Nuclear dendrin acted as a transcription factor to promote expression of cytosolic cathepsin L (CatL). CatL proteolyzed the regulatory GTPase dynamin and the actin-associated adapter synaptopodin, leading to a reorganization of the podocyte microfilament system and consequent proteinuria. CD2AP itself was proteolyzed by CatL, promoting sustained expression of the protease during podocyte injury, and in turn increasing the apoptotic susceptibility of podocytes to TGF-β1. Our study identifies CD2AP as the gatekeeper of the podocyte TGF-β response through its regulation of CatL expression and defines a molecular mechanism underlying proteinuric kidney disease.
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Affiliation(s)
- Suma Yaddanapudi
- Nephrology Division, Department of Medicine, Harvard Medical School and Massachusetts General Hospital, Charlestown, Massachusetts, USA
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