1
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Batool L, Hariharan K, Xu Y, Kaßmann M, Tsvetkov D, Gohlke BO, Kaden S, Gossen M, Nürnberg B, Kurtz A, Gollasch M. An inactivating human TRPC6 channel mutation without focal segmental glomerulosclerosis. Cell Mol Life Sci 2023; 80:265. [PMID: 37615749 PMCID: PMC10449997 DOI: 10.1007/s00018-023-04901-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 07/27/2023] [Accepted: 07/28/2023] [Indexed: 08/25/2023]
Abstract
Transient receptor potential cation channel-6 (TRPC6) gene mutations cause familial focal segmental glomerulosclerosis (FSGS), which is inherited as an autosomal dominant disease. In patients with TRPC6-related FSGS, all mutations map to the N- or C-terminal TRPC6 protein domains. Thus far, the majority of TRPC6 mutations are missense resulting in increased or decreased calcium influx; however, the fundamental molecular mechanisms causing cell injury and kidney pathology are unclear. We report a novel heterozygous TRPC6 mutation (V691Kfs*) in a large kindred with no signs of FSGS despite a largely truncated TRPC6 protein. We studied the molecular effects of V691Kfs* TRPC6 mutant using the tridimensional cryo-EM structure of the tetrameric TRPC6 protein. The results indicated that V691 is localized at the pore-forming transmembrane region affecting the ion conduction pathway, and predicted that V691Kfs* causes closure of the ion-conducting pathway leading to channel inactivation. We assessed the impact of V691Kfs* and two previously reported TRPC6 disease mutants (P112Q and G757D) on calcium influx in cells. Our data show that the V691Kfs* fully inactivated the TRCP6 channel-specific calcium influx consistent with a complete loss-of-function phenotype. Furthermore, the V691Kfs* truncation exerted a dominant negative effect on the full-length TRPC6 proteins. In conclusion, the V691Kfs* non-functional truncated TRPC6 is not sufficient to cause FSGS. Our data corroborate recently characterized TRPC6 loss-of-function and gain-of-function mutants suggesting that one defective TRPC6 gene copy is not sufficient to cause FSGS. We underscore the importance of increased rather than reduced calcium influx through TRPC6 for podocyte cell death.
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Affiliation(s)
- Lilas Batool
- BIH Center for Regenerative Therapies (BCRT), Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
| | - Krithika Hariharan
- BIH Center for Regenerative Therapies (BCRT), Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
- Fraunhofer-Institute for Biomedical Engineering (IBMT), Fraunhofer Project Center for Stem Cell Process Engineering, Würzburg, Germany
| | - Yao Xu
- Klinik und Poliklinik für Innere Medizin D-Geriatrie, Universitätsmedizin Greifswald, Ferdinand-Sauerbruch-Straße, Greifswald, Germany
| | - Mario Kaßmann
- Klinik und Poliklinik für Innere Medizin D-Geriatrie, Universitätsmedizin Greifswald, Ferdinand-Sauerbruch-Straße, Greifswald, Germany
| | - Dmitry Tsvetkov
- Klinik und Poliklinik für Innere Medizin D-Geriatrie, Universitätsmedizin Greifswald, Ferdinand-Sauerbruch-Straße, Greifswald, Germany
| | - Björn-Oliver Gohlke
- Department of Information Technology, Science-IT, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Sylvia Kaden
- Electron Microscopy Core Facility, German Cancer Research Center, Heidelberg, Germany
| | - Manfred Gossen
- BIH Center for Regenerative Therapies (BCRT), Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
- Institut für Aktive Polymere, Hereon TeltowAbteilung Stammzellmodifikation und Biomaterialien, Teltow, Germany
| | - Bernd Nürnberg
- Department of Pharmacology, Experimental Therapy and Toxicology, Institute of Experimental and Clinical Pharmacology and Pharmacogenomics, University of Tübingen, Tübingen, Germany
| | - Andreas Kurtz
- BIH Center for Regenerative Therapies (BCRT), Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany.
- Biomedical Data and Bioethics, Fraunhofer-Institute for Biomedical Engineering (IBMT), Berlin, Germany.
| | - Maik Gollasch
- Klinik und Poliklinik für Innere Medizin D-Geriatrie, Universitätsmedizin Greifswald, Ferdinand-Sauerbruch-Straße, Greifswald, Germany.
- Klinik für Nephrologie und Internistische Intensivmedizin, Charité-Universitätsmedizin Berlin, Berlin, Germany.
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2
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Ding Y, Tang X, Wang Y, Yu D, Zhu C, Yu J. Tetrandrine alleviates podocyte injury via calcium-dependent calpain-1 signaling blockade. BMC Complement Med Ther 2021; 21:296. [PMID: 34906112 PMCID: PMC8670271 DOI: 10.1186/s12906-021-03469-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 11/26/2021] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Podocytes have become a crucial target for interventions in proteinuric kidney diseases. Many studies have reported that overexpression of transient receptor potential cation channel protein 6 (TRPC6) in podocyte injury upregulates intracellular Ca2+ influx and stimulates Ca2+-dependent protease calpain-1 signaling. The traditional Chinese drug, tetrandrine, a nonselective Ca2+ channel blocker, has long been used to treat chronic kidney disease. This research aimed to explore the possible mechanisms underlying the anti-proteinuric properties of tetrandrine. METHODS We investigated the involvement of tetrandrine in Ca2+ dependent calpain-1 signaling in mouse podocytes and adriamycin-induced nephropathy rats. Cyclosporine A (CsA) and U73122 were used as positive controls. Cell viability, cytotoxicity, Ca2+ concentration, calpain activity, and mRNA and protein expression levels of calpain-1 signaling pathways were examined. The clinical and pathological changes were measured. RESULTS Tetrandrine decreased intracellular Ca2+ influx in cultured TRPC6-overexpressing podocytes. In both in vitro and in vivo studies, the administration of tetrandrine downregulated calpain activity and the expression of calpain-1 and restored the expression of downstream Talin-1 and nephrin. Compared to CsA, tetrandrine treatment exhibited superior inhibitory effects on calpain activity and calpain-1 expression. CONCLUSIONS Tetrandrine has therapeutic potential in podocyte damage by blocking Ca2+-dependent activation of the calpain-1 signaling pathway. Tetrandrine reduced proteinuria, improved renal function, and alleviate renal pathological damage.
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Affiliation(s)
- Yin Ding
- Department of Nephrology (Key laboratory of Management of Kidney Disease in Zhejiang Province), Hangzhou TCM Hospital Affiliated to Zhejiang Chinese Medical University, Tiyuchang Road 453, Hangzhou, 310007, People's Republic of China
| | - Xuanli Tang
- Department of Nephrology (Key laboratory of Management of Kidney Disease in Zhejiang Province), Hangzhou TCM Hospital Affiliated to Zhejiang Chinese Medical University, Tiyuchang Road 453, Hangzhou, 310007, People's Republic of China
| | - Yuhui Wang
- Department of Nephrology (Key laboratory of Management of Kidney Disease in Zhejiang Province), Hangzhou TCM Hospital Affiliated to Zhejiang Chinese Medical University, Tiyuchang Road 453, Hangzhou, 310007, People's Republic of China
| | - Dongrong Yu
- Department of Nephrology (Key laboratory of Management of Kidney Disease in Zhejiang Province), Hangzhou TCM Hospital Affiliated to Zhejiang Chinese Medical University, Tiyuchang Road 453, Hangzhou, 310007, People's Republic of China
| | - Caifeng Zhu
- Department of Nephrology (Key laboratory of Management of Kidney Disease in Zhejiang Province), Hangzhou TCM Hospital Affiliated to Zhejiang Chinese Medical University, Tiyuchang Road 453, Hangzhou, 310007, People's Republic of China
| | - Jin Yu
- Department of Nephrology (Key laboratory of Management of Kidney Disease in Zhejiang Province), Hangzhou TCM Hospital Affiliated to Zhejiang Chinese Medical University, Tiyuchang Road 453, Hangzhou, 310007, People's Republic of China.
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3
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Orrego PR, Serrano-Rodríguez M, Cortez M, Araya JE. In Silico Characterization of Calcineurin from Pathogenic Obligate Intracellular Trypanosomatids: Potential New Biological Roles. Biomolecules 2021; 11:biom11091322. [PMID: 34572535 PMCID: PMC8470620 DOI: 10.3390/biom11091322] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 07/16/2021] [Accepted: 08/09/2021] [Indexed: 12/28/2022] Open
Abstract
Calcineurin (CaN) is present in all eukaryotic cells, including intracellular trypanosomatid parasites such as Trypanosoma cruzi (Tc) and Leishmania spp. (Lspp). In this study, we performed an in silico analysis of the CaN subunits, comparing them with the human (Hs) and looking their structure, post-translational mechanisms, subcellular distribution, interactors, and secretion potential. The differences in the structure of the domains suggest the existence of regulatory mechanisms and differential activity between these protozoa. Regulatory subunits are partially conserved, showing differences in their Ca2+-binding domains and myristoylation potential compared with human CaN. The subcellular distribution reveals that the catalytic subunits TcCaNA1, TcCaNA2, LsppCaNA1, LsppCaNA1_var, and LsppCaNA2 associate preferentially with the plasma membrane compared with the cytoplasmic location of HsCaNAα. For regulatory subunits, HsCaNB-1 and LsppCaNB associate preferentially with the nucleus and cytoplasm, and TcCaNB with chloroplast and cytoplasm. Calpain cleavage sites on CaNA suggest differential processing. CaNA and CaNB of these trypanosomatids have the potential to be secreted and could play a role in remote communication. Therefore, this background can be used to develop new drugs for protozoan pathogens that cause neglected disease.
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Affiliation(s)
- Patricio R. Orrego
- Departamento Biomédico, Facultad de Ciencias de la Salud, Universidad de Antofagasta, Antofagasta 1270300, Chile
- Correspondence: (P.R.O.); (J.E.A.); Tel.: +56-55-2637664 (J.E.A.)
| | - Mayela Serrano-Rodríguez
- Departamento de Tecnología Médica, Facultad de Ciencias de la Salud, Universidad de Antofagasta, Antofagasta 1270300, Chile;
| | - Mauro Cortez
- Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo 05508-000, Brazil;
| | - Jorge E. Araya
- Departamento de Tecnología Médica, Facultad de Ciencias de la Salud, Universidad de Antofagasta, Antofagasta 1270300, Chile;
- Center for Biotechnology and Bioengineering, CeBIB, Universidad de Antofagasta, Antofagasta 1270300, Chile
- Correspondence: (P.R.O.); (J.E.A.); Tel.: +56-55-2637664 (J.E.A.)
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Iranzad R, Motavalli R, Ghassabi A, Pourakbari R, Etemadi J, Yousefi M. Roles of microRNAs in renal disorders related to primary podocyte dysfunction. Life Sci 2021; 277:119463. [PMID: 33862110 DOI: 10.1016/j.lfs.2021.119463] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 03/19/2021] [Accepted: 03/27/2021] [Indexed: 12/20/2022]
Abstract
Through the regulation of gene expression, microRNAs (miRNAs) are capable of modulating vital biological processes, such as proliferation, differentiation, and apoptosis. Several mechanisms control the function of miRNAs, including translational inhibition and targeted miRNA degradation. Through utilizing high-throughput screening methods, such as small RNA sequencing and microarray, alterations in miRNA expression of kidneys have recently been observed both in rodent models and humans throughout the development of chronic kidney disease (CKD) and acute kidney injury (AKI). The levels of miRNAs in urine supernatant, sediment, and exosomal fraction could predict novel biomarker candidates in different diseases of kidneys, including IgA nephropathy, lupus nephritis, and diabetic nephropathy. The therapeutic potential of administrating anti-miRNAs and miRNAs has also been reported recently. The present study is aimed at reviewing the state-of-the-art research with regards to miRNAs involved in renal disorders related to primary podocyte dysfunction by laying particular emphasis on Focal Segmental Glomerulosclerosis (FSGS), Minimal Change Disease (MCD) and Membranous Nephropathy (MN).
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Affiliation(s)
- Rahim Iranzad
- Tabriz University of Medical Sciences, Tabriz, Iran; Stem Cell Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Roza Motavalli
- Stem Cell Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Kidney Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Ali Ghassabi
- Stem Cell Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Ramin Pourakbari
- Tabriz University of Medical Sciences, Tabriz, Iran; Stem Cell Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Jalal Etemadi
- Stem Cell Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Kidney Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mehdi Yousefi
- Stem Cell Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
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5
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Huang LM, Mao JH. Glomerular podocyte dysfunction in inherited renal tubular disease. World J Pediatr 2021; 17:227-233. [PMID: 33625696 PMCID: PMC8253710 DOI: 10.1007/s12519-021-00417-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 01/20/2021] [Indexed: 11/26/2022]
Abstract
BACKGROUND Hereditary renal tubular disease can cause hypercalciuria, acid-base imbalance, hypokalemia, hypomagnesemia, rickets, kidney stones, etc. If these diseases are not diagnosed or treated in time, they can cause kidney damage and electrolyte disturbances, which can be detrimental to the maturation and development of the child. Glomerular involvement in renal tubular disease patients has only been considered recently. METHODS We screened 71 papers (including experimental research, clinical research, etc.) about Dent's disease, Gitelman syndrome, and cystinosis from PubMed, and made reference. RESULTS Glomerular disease was initially underestimated among the clinical signs of renal tubular disease or was treated merely as a consequence of the tubular damage. Renal tubular diseases affect glomerular podocytes through certain mechanisms resulting in functional damage, morphological changes, and glomerular lesions. CONCLUSIONS This article focuses on the progress of changes in glomerular podocyte function in Dent disease, Gitelman syndrome, and cystinosis for the purposes of facilitating clinically accurate diagnosis and scientific treatment and improving prognosis.
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Affiliation(s)
- Li-Min Huang
- Department of Nephrology, National Clinical Research Center for Child Health, The Children's Hospital, Zhejiang University School of Medicine, #57 Zhugan Lane, Hangzhou 310006, China
| | - Jian-Hua Mao
- Department of Nephrology, National Clinical Research Center for Child Health, The Children's Hospital, Zhejiang University School of Medicine, #57 Zhugan Lane, Hangzhou 310006, China.
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6
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Fujitaka K, Murakami T, Takeuchi M, Kakimoto T, Mochida H, Arakawa K. mRNAs in urinary nano-extracellular vesicles as potential biomarkers for non-invasive kidney biopsy. Biomed Rep 2020; 14:11. [PMID: 33235726 PMCID: PMC7678616 DOI: 10.3892/br.2020.1387] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 10/16/2020] [Indexed: 12/17/2022] Open
Abstract
Urinary nano-extracellular vesicles (NVs), including exosomes and microvesicles, are considered potential biomarkers for kidney diseases using liquid biopsies. However, clinical application of urinary NVs has not yet been validated. In the present study, the levels of mRNAs in urinary NVs in animal models of kidney disease were assessed. Urine samples were collected from the animal models and urinary NVs were isolated by ultracentrifugation. Gene expression levels of kidney injury markers in urinary NVs and renal tissue were quantified by reverse transcription-quantitative PCR. The mRNA levels of desmin, a podocyte injury marker, in urinary NVs was markedly increased in the puromycin aminonucleoside (PAN) nephritis model, in parallel with enhanced desmin expression in kidney tissues. The expression of regulator of calcineurin 1 and the podocin to nephrin ratio (PNR) were also increased in the PAN nephritis model. Treatment with prednisolone mitigated these changes in gene expression as well as proteinuria. PNR, which is considered a predictive marker of glomerular dysfunction, in urinary NVs was highly correlated with urinary protein excretion (P<0.01). Furthermore, PNR in urinary NVs of Zucker diabetic fatty rats, a diabetic kidney disease model, was correlated with urinary albumin excretion (P<0.01). These results suggest that changes in mRNA levels of urinary NVs reflect the disease status of kidney tissues and their functional alterations. Collectively, mRNA analysis of urinary NVs may be used as a liquid biopsy tool for improved classification and performance of risk prediction to determine the severity of kidney diseases.
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Affiliation(s)
- Keisuke Fujitaka
- Research Unit/Frontier, Sohyaku Innovative Research Division, Mitsubishi Tanabe Pharma Corporation, Fujisawa-shi, Kanagawa 251-8555, Japan.,Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-0005, Japan
| | - Taku Murakami
- Hitachi Chemical Co. America, Ltd., R&D Center, Irvine, CA 92617, USA
| | - Masato Takeuchi
- Medical Affairs Department, Ikuyaku Integrated Value Development Division, Mitsubishi Tanabe Pharma Corporation, Osaka 541-8505, Japan
| | - Tetsuhiro Kakimoto
- Research Unit/Frontier, Sohyaku Innovative Research Division, Mitsubishi Tanabe Pharma Corporation, Fujisawa-shi, Kanagawa 251-8555, Japan
| | - Hideki Mochida
- Research Unit/Frontier, Sohyaku Innovative Research Division, Mitsubishi Tanabe Pharma Corporation, Fujisawa-shi, Kanagawa 251-8555, Japan
| | - Kenji Arakawa
- Medical Intelligence Department, Ikuyaku Integrated Value Development Division, Mitsubishi Tanabe Pharma Corporation, Tokyo 103-8405, Japan
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Farmer LK, Rollason R, Whitcomb DJ, Ni L, Goodliff A, Lay AC, Birnbaumer L, Heesom KJ, Xu SZ, Saleem MA, Welsh GI. TRPC6 Binds to and Activates Calpain, Independent of Its Channel Activity, and Regulates Podocyte Cytoskeleton, Cell Adhesion, and Motility. J Am Soc Nephrol 2019; 30:1910-1924. [PMID: 31416818 DOI: 10.1681/asn.2018070729] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 06/17/2019] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND Mutations in the transient receptor potential channel 6 (TRPC6) gene are associated with an inherited form of FSGS. Despite widespread expression, patients with TRPC6 mutations do not present with any other pathologic phenotype, suggesting that this protein has a unique yet unidentified role within the target cell for FSGS, the kidney podocyte. METHODS We generated a stable TRPC6 knockout podocyte cell line from TRPC6 knockout mice. These cells were engineered to express wild-type TRPC6, a dominant negative TRPC6 mutation, or either of two disease-causing mutations of TRPC6, G109S or K874*. We extensively characterized these cells using motility, detachment, and calpain activity assays; immunofluorescence; confocal or total internal reflection fluorescence microscopy; and western blotting. RESULTS Compared with wild-type cells, TRPC6-/- podocytes are less motile and more adhesive, with an altered actin cytoskeleton. We found that TRPC6 binds to ERK1/2 and the actin regulatory proteins, caldesmon (a calmodulin- and actin-binding protein) and calpain 1 and 2 (calcium-dependent cysteine proteases that control the podocyte cytoskeleton, cell adhesion, and motility via cleavage of paxillin, focal adhesion kinase, and talin). Knockdown or expression of the truncated K874* mutation (but not expression of the gain-of-function G019S mutation or dominant negative mutant of TRPC6) results in the mislocalization of calpain 1 and 2 and significant downregulation of calpain activity; this leads to altered podocyte cytoskeleton, motility, and adhesion-characteristics of TRPC6 -/- podocytes. CONCLUSIONS Our data demonstrate that independent of TRPC6 channel activity, the physical interaction between TRPC6 and calpain in the podocyte is important for cell motility and detachment and demonstrates a scaffolding role of the TRPC6 protein in disease.
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Affiliation(s)
| | | | - Daniel J Whitcomb
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, Bristol Medical School, and
| | - Lan Ni
- Bristol Renal, Bristol Medical School
| | | | | | - Lutz Birnbaumer
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina.,Faculty of Medical Sciences, Institute of Biomedical Research, Catholic University of Argentina, Buenos Aires, Argentina; and
| | - Kate J Heesom
- Proteomics Facility, University of Bristol, Bristol, United Kingdom
| | - Shang-Zhong Xu
- Centre for Cardiovascular and Metabolic Research, Hull York Medical School, University of Hull, Hull, United Kingdom
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Vo TM, Jain S, Burchett R, Monckton EA, Godbout R. A positive feedback loop involving nuclear factor IB and calpain 1 suppresses glioblastoma cell migration. J Biol Chem 2019; 294:12638-12654. [PMID: 31262726 DOI: 10.1074/jbc.ra119.008291] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 06/27/2019] [Indexed: 12/15/2022] Open
Abstract
Glioblastoma (GBM) is a brain tumor that remains largely incurable because of its highly-infiltrative properties. Nuclear factor I (NFI)-type transcription factors regulate genes associated with GBM cell migration and infiltration. We have previously shown that NFI activity depends on the NFI phosphorylation state and that calcineurin phosphatase dephosphorylates and activates NFI. Calcineurin is cleaved and activated by calpain proteases whose activity is, in turn, regulated by an endogenous inhibitor, calpastatin (CAST). The CAST gene is a target of NFI in GBM cells, with differentially phosphorylated NFIs regulating the levels of CAST transcript variants. Here, we uncovered an NFIB-calpain 1-positive feedback loop mediated through CAST and calcineurin. In NFI-hyperphosphorylated GBM cells, NFIB expression decreased the CAST-to-calpain 1 ratio in the cytoplasm. This reduced ratio increased autolysis and activity of cytoplasmic calpain 1. Conversely, in NFI-hypophosphorylated cells, NFIB expression induced differential subcellular compartmentalization of CAST and calpain 1, with CAST localizing primarily to the cytoplasm and calpain 1 to the nucleus. Overall, this altered compartmentalization increased nuclear calpain 1 activity. We also show that nuclear calpain 1, by cleaving and activating calcineurin, induces NFIB dephosphorylation. Of note, knockdown of calpain 1, NFIB, or both increased GBM cell migration and up-regulated the pro-migratory factors fatty acid-binding protein 7 (FABP7) and Ras homolog family member A (RHOA). In summary, our findings reveal bidirectional cross-talk between NFIB and calpain 1 in GBM cells. A physiological consequence of this positive feedback loop appears to be decreased GBM cell migration.
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Affiliation(s)
- The Minh Vo
- Cross Cancer Institute, Department of Oncology, University of Alberta, Edmonton, Alberta T6G 1Z2, Canada
| | - Saket Jain
- Cross Cancer Institute, Department of Oncology, University of Alberta, Edmonton, Alberta T6G 1Z2, Canada
| | - Rebecca Burchett
- Cross Cancer Institute, Department of Oncology, University of Alberta, Edmonton, Alberta T6G 1Z2, Canada
| | - Elizabeth A Monckton
- Cross Cancer Institute, Department of Oncology, University of Alberta, Edmonton, Alberta T6G 1Z2, Canada
| | - Roseline Godbout
- Cross Cancer Institute, Department of Oncology, University of Alberta, Edmonton, Alberta T6G 1Z2, Canada
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9
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Vo TM, Burchett R, Brun M, Monckton EA, Poon HY, Godbout R. Effects of nuclear factor I phosphorylation on calpastatin ( CAST) gene variant expression and subcellular distribution in malignant glioma cells. J Biol Chem 2019; 294:1173-1188. [PMID: 30504225 DOI: 10.1074/jbc.ra118.004787] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2018] [Revised: 11/29/2018] [Indexed: 12/20/2022] Open
Abstract
Malignant glioma (MG) is the most lethal primary brain tumor. In addition to having inherent resistance to radiation treatment and chemotherapy, MG cells are highly infiltrative, rendering focal therapies ineffective. Genes involved in MG cell migration and glial cell differentiation are up-regulated by hypophosphorylated nuclear factor I (NFI), which is dephosphorylated by the phosphatase calcineurin in MG cells. Calcineurin is cleaved and thereby activated by calpain proteases, which are, in turn, inhibited by calpastatin (CAST). Here, we show that the CAST gene is a target of NFI and has NFI-binding sites in its intron 3 region. We also found that NFI-mediated regulation of CAST depends on NFI's phosphorylation state. We noted that occupation of CAST intron 3 by hypophosphorylated NFI results in increased activation of an alternative promoter. This activation resulted in higher levels of CAST transcript variants, leading to increased levels of CAST protein that lacks the N-terminal XL domain. CAST was primarily present in the cytoplasm of NFI-hypophosphorylated MG cells, with a predominantly perinuclear immunostaining pattern. NFI knockdown in NFI-hypophosphorylated MG cells increased CAST levels at the plasma membrane. These results suggest that NFI plays an integral role in the regulation of CAST variants and CAST subcellular distribution. Along with the previous findings indicating that NFI activity is regulated by calcineurin, these results provide a foundation for further investigations into the possibility of regulatory cross-talk between NFI and the CAST/calpain/calcineurin signaling pathway in MG cells.
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Affiliation(s)
- The Minh Vo
- Department of Oncology, University of Alberta, Cross Cancer Institute, Edmonton, Alberta T6G 1Z2, Canada
| | - Rebecca Burchett
- Department of Oncology, University of Alberta, Cross Cancer Institute, Edmonton, Alberta T6G 1Z2, Canada
| | - Miranda Brun
- Department of Oncology, University of Alberta, Cross Cancer Institute, Edmonton, Alberta T6G 1Z2, Canada
| | - Elizabeth A Monckton
- Department of Oncology, University of Alberta, Cross Cancer Institute, Edmonton, Alberta T6G 1Z2, Canada
| | - Ho-Yin Poon
- Department of Oncology, University of Alberta, Cross Cancer Institute, Edmonton, Alberta T6G 1Z2, Canada
| | - Roseline Godbout
- Department of Oncology, University of Alberta, Cross Cancer Institute, Edmonton, Alberta T6G 1Z2, Canada.
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10
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Rinschen MM, Huesgen PF, Koch RE. The podocyte protease web: uncovering the gatekeepers of glomerular disease. Am J Physiol Renal Physiol 2018; 315:F1812-F1816. [PMID: 30230368 DOI: 10.1152/ajprenal.00380.2018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Proteases regulate glomerular physiology. The last decade has revealed a multitude of podocyte proteases that govern the glomerular response to numerous chemical, mechanical, and metabolic cues. These proteases form a protein signaling web that integrates stress stimuli and serves as a key controller of the glomerular microenvironment. Both the extracellular and intracellular proteolytic networks are perturbed in focal segmental glomerulosclerosis, as well as hypertensive and diabetic nephropathy. Accordingly, the highly intertwined podocyte protease web is an integrative part of the podocyte's damage response. Novel mass spectrometry-based technologies will help to untangle this proteolytic network: functional readouts acquired from deep podocyte proteomics, single glomerular proteomics, and degradomics have exposed unanticipated protease activity in podocytes. Future efforts should characterize the interdependency and upstream regulation of key proteases, along with their role in promoting tissue heterogeneity in glomerular diseases. These efforts will not only illuminate the machinery of podocyte proteostasis but also reveal avenues for therapeutic intervention in the podocyte protease web.
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Affiliation(s)
- Markus M Rinschen
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne , Cologne , Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne , Cologne , Germany.,Center for Mass Spectrometry and Metabolomics, The Scripps Research Institute , La Jolla, California
| | - Pitter F Huesgen
- Central Institute for Engineering, Electronics and Analytics ZEA-3, Forschungszentrum Jülich, Jülich , Germany
| | - Rachelle E Koch
- Division of Graduate Medical Sciences, Boston University School of Medicine , Boston, Massachusetts
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Verheijden KAT, Sonneveld R, Bakker-van Bebber M, Wetzels JFM, van der Vlag J, Nijenhuis T. The Calcium-Dependent Protease Calpain-1 Links TRPC6 Activity to Podocyte Injury. J Am Soc Nephrol 2018; 29:2099-2109. [PMID: 29954830 DOI: 10.1681/asn.2016111248] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Accepted: 06/08/2018] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND The hallmark of podocytopathies, such as FSGS, is podocyte injury resulting in proteinuria. Transient receptor potential channel C6 (TRPC6) is a calcium-conducting ion channel expressed at the slit diaphragm. TRPC6 gain-of-function mutations and glomerular TRPC6 overexpression are associated with proteinuria. However, the pathways linking TRPC6 to podocyte injury, which is characterized by loss of the slit diaphragm protein nephrin, activation of several intracellular pathways (including calcineurin-NFAT signaling), and cytoskeletal rearrangement, remain elusive. METHODS We tested whether the calcium-dependent protease calpain-1 mediates TRPC6-dependent podocyte injury in human and experimental FSGS and cultured podocytes. RESULTS Compared with kidneys of healthy controls, kidneys of patients with FSGS had increased TRPC6 expression, increased calpain and calcineurin activity, and reduced expression of the calpain target Talin-1, which links the actin cytoskeleton to integrins and is critical for podocyte cytoskeletal stability. In a rat model of human FSGS, increased glomerular and urinary calpain activity associated with reduced Talin-1 abundance, enhanced calcineurin activity, and increased proteinuria. Treatment with the calpain inhibitor calpeptin prevented these effects. In cultured podocytes, pharmacologic stimulation of TRPC6-dependent calcium influx increased calpain-1 and calcineurin activity and reduced Talin-1 expression, and knockdown of TRPC6 or calpain-1 prevented these effects. CONCLUSIONS We elucidated a novel mechanism that links TRPC6 activity to calpain-1 activation and through Talin-1 loss and possibly, calcineurin activation, the podocyte injury characterizing FSGS. Therefore, calpain-1 and/or TRPC6 inhibition could be future therapeutic options to treat patients with FSGS or other podocytopathies.
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Affiliation(s)
- Kim A T Verheijden
- Department of Nephrology, Radboud Institute of Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ramon Sonneveld
- Department of Nephrology, Radboud Institute of Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Marinka Bakker-van Bebber
- Department of Nephrology, Radboud Institute of Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jack F M Wetzels
- Department of Nephrology, Radboud Institute of Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Johan van der Vlag
- Department of Nephrology, Radboud Institute of Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Tom Nijenhuis
- Department of Nephrology, Radboud Institute of Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
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Solanki AK, Arif E, Morinelli T, Wilson RC, Hardiman G, Deng P, Arthur JM, Velez JC, Nihalani D, Janech MG, Budisavljevic MN. A Novel CLCN5 Mutation Associated With Focal Segmental Glomerulosclerosis and Podocyte Injury. Kidney Int Rep 2018; 3:1443-1453. [PMID: 30426109 PMCID: PMC6224352 DOI: 10.1016/j.ekir.2018.06.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 06/05/2018] [Accepted: 06/09/2018] [Indexed: 12/17/2022] Open
Abstract
Introduction Tubular dysfunction is characteristic of Dent’s disease; however, focal segmental glomerulosclerosis (FSGS) can also be present. Glomerulosclerosis could be secondary to tubular injury, but it remains uncertain whether the CLCN5 gene, which encodes an endosomal chloride and/or hydrogen exchanger, plays a role in podocyte biology. Here, we implicate a role for CLCN5 in podocyte function and pathophysiology. Methods Whole exome capture and sequencing of the proband and 5 maternally-related family members was conducted to identify X-linked mutations associated with biopsy-proven FSGS. Human podocyte cultures were used to characterize the mutant phenotype on podocyte function. Results We identified a novel mutation (L521F) in CLCN5 in 2 members of a Hispanic family who presented with a histologic diagnosis of FSGS and low-molecular-weight proteinuria without hypercalciuria. Presence of CLCN5 was confirmed in cultured human podocytes. Podocytes transfected with the wild-type or the mutant (L521F) CLCN5 constructs showed differential localization. CLCN5 knockdown in podocytes resulted in defective transferrin endocytosis and was associated with decreased cell proliferation and increased cell migration, which are hallmarks of podocyte injury. Conclusions The CLCN5 mutation, which causes Dent’s disease, may be associated with FSGS without hyercalcuria and nepthrolithiasis. The present findings supported the hypothesis that CLCN5 participates in protein trafficking in podocytes and plays a critical role in organizing the components of the podocyte slit diaphragm to help maintain normal cell physiology and a functional filtration barrier. In addition to tubular dysfunction, mutations in CLCN5 may also lead to podocyte dysfunction, which results in a histologic picture of FSGS that may be a primary event and not a consequence of tubular damage.
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Affiliation(s)
- Ashish K Solanki
- Department of Medicine, Nephrology Division, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Ehtesham Arif
- Department of Medicine, Nephrology Division, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Thomas Morinelli
- Division of Transplant Surgery, Department of Surgery, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Robert C Wilson
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Gary Hardiman
- Department of Medicine, Nephrology Division, Medical University of South Carolina, Charleston, South Carolina, USA.,MUSC Bioinformatics, Center for Genomics Medicine, Medical University of South Carolina, Charleston, South Carolina, USA.,Department of Public Health Sciences, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Peifeng Deng
- Department of Medicine, Nephrology Division, Medical University of South Carolina, Charleston, South Carolina, USA
| | - John M Arthur
- Division of Nephrology, Department of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Juan Cq Velez
- Department of Nephrology, Ochsner Clinic Foundation, New Orleans, Louisiana, USA
| | - Deepak Nihalani
- Department of Medicine, Nephrology Division, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Michael G Janech
- Department of Medicine, Nephrology Division, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Milos N Budisavljevic
- Department of Medicine, Nephrology Division, Medical University of South Carolina, Charleston, South Carolina, USA.,Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina, USA
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Taurine Supplementation Alleviates Puromycin Aminonucleoside Damage by Modulating Endoplasmic Reticulum Stress and Mitochondrial-Related Apoptosis in Rat Kidney. Nutrients 2018; 10:nu10060689. [PMID: 29843457 PMCID: PMC6024760 DOI: 10.3390/nu10060689] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 05/24/2018] [Accepted: 05/25/2018] [Indexed: 12/27/2022] Open
Abstract
Taurine (TAU) is a sulfur-containing beta amino acid that is not involved in protein composition and anabolism, conditionally essential in mammals provided through diet. Growing evidence supports a protective role of TAU supply in osmoregulation, calcium flux, and reduction of inflammation and oxidant damage in renal diseases like diabetes. Endoplasmic reticulum (ER) stress, due to abnormal proteostasis, is a contributor to nephrotic syndrome and related renal damage. Here, we investigated the effect of dietary TAU (1.5% in drinking water for 15 days) in an established rat model that mimics human minimal change nephrosis, consisting of a single puromycin aminonucleoside (PAN) injection (intraperitoneally 15 mg/100 g body weight), with sacrifice after eight days. TAU limited proteinuria and podocytes foot processes effacement, and balanced slit diaphragm nephrin and glomerular claudin 1 expressions. In cortical proximal tubules, TAU improved lysosomal density, ER perimeter, restored proper ER-mitochondria tethering and mitochondrial cristae, and decreased inflammation. Remarkably, TAU downregulated glomerular ER stress markers (GRP78, GRP94), pro-apoptotic C/EBP homologous protein, activated caspase 3, tubular caspase1, and mitochondrial chaperone GRP75, but maintained anti-apoptotic HSP25. In conclusion, TAU, by targeting upstream ER stress separate from mitochondria dysfunctions at crucial renal sites, might be a promising dietary supplement in the treatment of the drug-resistant nephrotic syndrome.
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Zhang K, Sun W, Zhang L, Xu X, Wang J, Hong Y. miR-499 Ameliorates Podocyte Injury by Targeting Calcineurin in Minimal Change Disease. Am J Nephrol 2018; 47:94-102. [PMID: 29448244 DOI: 10.1159/000486967] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 01/13/2018] [Indexed: 12/11/2022]
Abstract
BACKGROUND Podocyte injury is a hallmark of minimal change disease (MCD). Calcineurin inhibitors have been widely used in the current treatment of MCD, and miR-499 may target calcineurin. We aimed to study the function of miR-499 in MCD and test whether miR-499 delivery can improve MCD. METHODS An MCD mouse model was generated using puromycin aminonucleoside (PAN). MiR-499 was delivered using lentiviruses. Biochemical indicators including serum albumin, triglyceride, cholesterol, and 24-h urine protein were determined. Targets of miR-499 were confirmed using reporter gene activity assays. The ultrastructure of podocytes was analyzed using transmission electron microscopy. RESULTS MiR-499 significantly improved MCD-related symptoms and signs. Foot-process effacement was caused by PAN and partially reversed by miR-499. We identified that both CnAα and CnAβ were targets of miR-499, and were overexpressed in the presence of PAN. However, miR-499 reduced the expression of CnAα and CnAβ, leading to a decreased activity of calcineurin signaling in mouse podocytes in vitro and in vivo. In addition, miR-499 recovered PAN-induced reduction of cell viability. CONCLUSIONS MiR-499 ameliorated podocyte injury by targeting CnAα and CnAβ in a PAN-induced MCD mouse model. Delivery of miR-499 can be a novel strategy for MCD treatment.
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Lei Y, Wang C, Jiang Q, Sun X, Du Y, Zhu Y, Lu Y. Calpain activation and disturbance of autophagy are induced in cortical neurons in vitro by exposure to HA/ β-Ga 2O 3:Cr 3+ nanoparticles. PeerJ 2018; 6:e4365. [PMID: 29441243 PMCID: PMC5807884 DOI: 10.7717/peerj.4365] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 01/23/2018] [Indexed: 01/14/2023] Open
Abstract
The toxicity of engineered nanoparticles remains a concern. The knowledge of biohazards associated with particular nanoparticles is crucial to make this cutting-edge technology more beneficial and safe. Here, we evaluated the toxicity of Ga2O3 nanoparticles (NPs), which are frequently used to enhance the performance of metal catalysts in a variety of catalytic reactions. The potential inflammatory signaling associated with the toxicity of HA/β-Ga2O3:Cr3+ NPs in primary cortical neurons was examined. We observed a dose-dependent decrease in cell viability and an increase in apoptosis in neurons following various concentrations (0, 1, 5, 25, 50, 100 µg/ml) of HA/β-Ga2O3:Cr3+ NPs treatment. Consistently, constitutively active forms of calcineurin (48 kDa) were significantly elevated in cultured primary cortical neurons, which was consistent with calpain activation indicated by the breakdown products of spectrin. Moreover, HA/β-Ga2O3:Cr3+ NPs result in the elevation of LC3-II formation, SQSTM/p62, and Cathepsin B, whereas phosphorylation of CaMKII (Thr286) and Synapsin I (Ser603) were downregulated in the same context. Taken together, these results demonstrate for the first time that calpain activation and a disturbance of autophagy signaling are evoked by exposure to HA/β-Ga2O3:Cr3+ NPs, which may contribute to neuronal injury in vitro.
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Affiliation(s)
- Yu Lei
- College of Pharmaceutical Sciences, Zhejiang Unviersity, Hangzhou, Zhejiang Province, China
| | - Chengkun Wang
- College of Pharmaceutical Sciences, Zhejiang Unviersity, Hangzhou, Zhejiang Province, China
| | - Quan Jiang
- College of Pharmaceutical Sciences, Zhejiang Unviersity, Hangzhou, Zhejiang Province, China
| | - Xiaoyi Sun
- School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang Province, China
| | - Yongzhong Du
- College of Pharmaceutical Sciences, Zhejiang Unviersity, Hangzhou, Zhejiang Province, China
| | - Yaofeng Zhu
- Key Laboratory of Advanced Textile Materials and Manufacturing Technology of the Ministry of Education, Zhejiang Sci-Tech University, Hangzhou, Zhejiang Province, China
| | - Yingmei Lu
- School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang Province, China
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