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PI(4,5)P2 controls slit diaphragm formation and endocytosis in Drosophila nephrocytes. Cell Mol Life Sci 2022; 79:248. [PMID: 35437696 PMCID: PMC9016003 DOI: 10.1007/s00018-022-04273-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 03/01/2022] [Accepted: 03/24/2022] [Indexed: 12/03/2022]
Abstract
Drosophila nephrocytes are an emerging model system for mammalian podocytes and proximal tubules as well as for the investigation of kidney diseases. Like podocytes, nephrocytes exhibit characteristics of epithelial cells, but the role of phospholipids in polarization of these cells is yet unclear. In epithelia, phosphatidylinositol(4,5)bisphosphate (PI(4,5)P2) and phosphatidylinositol(3,4,5)-trisphosphate (PI(3,4,5)P3) are asymmetrically distributed in the plasma membrane and determine apical–basal polarity. Here, we demonstrate that both phospholipids are present in the plasma membrane of nephrocytes, but only PI(4,5)P2 accumulates at slit diaphragms. Knockdown of Skittles, a phosphatidylinositol(4)phosphate 5-kinase, which produces PI(4,5)P2, abolished slit diaphragm formation and led to strongly reduced endocytosis. Notably, reduction in PI(3,4,5)P3 by overexpression of PTEN or expression of a dominant-negative phosphatidylinositol-3-kinase did not affect nephrocyte function, whereas enhanced formation of PI(3,4,5)P3 by constitutively active phosphatidylinositol-3-kinase resulted in strong slit diaphragm and endocytosis defects by ectopic activation of the Akt/mTOR pathway. Thus, PI(4,5)P2 but not PI(3,4,5)P3 is essential for slit diaphragm formation and nephrocyte function. However, PI(3,4,5)P3 has to be tightly controlled to ensure nephrocyte development.
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2
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Maywald ML, Picciotto C, Lepa C, Bertgen L, Yousaf FS, Ricker A, Klingauf J, Krahn MP, Pavenstädt H, George B. Rap1 Activity Is Essential for Focal Adhesion and Slit Diaphragm Integrity. Front Cell Dev Biol 2022; 10:790365. [PMID: 35372328 PMCID: PMC8972170 DOI: 10.3389/fcell.2022.790365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 02/24/2022] [Indexed: 11/24/2022] Open
Abstract
Glomerular podocytes build, with their intercellular junctions, part of the kidney filter. The podocyte cell adhesion protein, nephrin, is essential for developing and maintaining slit diaphragms as functional loss in humans results in heavy proteinuria. Nephrin expression and function are also altered in many adult-onset glomerulopathies. Nephrin signals from the slit diaphragm to the actin cytoskeleton and integrin β1 at focal adhesions by recruiting Crk family proteins, which can interact with the Rap guanine nucleotide exchange factor 1 C3G. As Rap1 activity affects focal adhesion formation, we hypothesize that nephrin signals via Rap1 to integrin β. To address this issue, we combined Drosophila in vivo and mammalian cell culture experiments. We find that Rap1 is necessary for correct targeting of integrin β to focal adhesions in Drosophila nephrocytes, which also form slit diaphragm-like structures. In the fly, the Rap1 activity is important for signaling of the nephrin ortholog to integrin β, as well as for nephrin-dependent slit diaphragm integrity. We show by genetic interaction experiments that Rap1 functions downstream of nephrin signaling to integrin β and downstream of nephrin signaling necessary for slit diaphragm integrity. Similarly, in human podocyte culture, nephrin activation results in increased activation of Rap1. Thus, Rap1 is necessary for downstream signal transduction of nephrin to integrin β.
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Affiliation(s)
- Mee-Ling Maywald
- Medizinische Klinik D, University Hospital Münster, Münster, Germany
| | - Cara Picciotto
- Medizinische Klinik D, University Hospital Münster, Münster, Germany
| | - Carolin Lepa
- Medizinische Klinik D, University Hospital Münster, Münster, Germany
| | - Luisa Bertgen
- Medizinische Klinik D, University Hospital Münster, Münster, Germany
| | | | - Andrea Ricker
- Institute of Medical Physics and Biophysics, Westfälische Wilhelms-University Münster, Münster, Germany
| | - Jürgen Klingauf
- Institute of Medical Physics and Biophysics, Westfälische Wilhelms-University Münster, Münster, Germany
| | - Michael P. Krahn
- Medizinische Klinik D, Medical Cell Biology, University Hospital Münster, Münster, Germany
| | | | - Britta George
- Medizinische Klinik D, University Hospital Münster, Münster, Germany
- *Correspondence: Britta George,
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3
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Han P, Yue J, Kong K, Hu S, Cao P, Deng Y, Li F, Zhao B. Signature identification of relapse-related overall survival of early lung adenocarcinoma after radical surgery. PeerJ 2021; 9:e11923. [PMID: 34430085 PMCID: PMC8349519 DOI: 10.7717/peerj.11923] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 07/16/2021] [Indexed: 12/14/2022] Open
Abstract
Background The widespread use of low-dose chest CT screening has improved the detection of early lung adenocarcinoma. Radical surgery is the best treatment strategy for patients with early lung adenocarcinoma; however, some patients present with postoperative recurrence and poor prognosis. Through this study, we hope to establish a model that can identify patients that are prone to recurrence and have poor prognosis after surgery for early lung adenocarcinoma. Materials and Methods We screened prognostic and relapse-related genes using The Cancer Genome Atlas (TCGA) database and the GSE50081 dataset from the Gene Expression Omnibus (GEO) database. The GSE30219 dataset was used to further screen target genes and construct a risk prognosis signature. Time-dependent ROC analysis, calibration degree analysis, and DCA were used to evaluate the reliability of the model. We validated the TCGA dataset, GSE50081, and GSE30219 internally. External validation was conducted in the GSE31210 dataset. Results A novel four-gene signature (INPP5B, FOSL2, CDCA3, RASAL2) was established to predict relapse-related survival outcomes in patients with early lung adenocarcinoma after surgery. The discovery of these genes may reveal the molecular mechanism of recurrence and poor prognosis of early lung adenocarcinoma. In addition, ROC analysis, calibration analysis and DCA were used to verify the genetic signature internally and externally. Our results showed that our gene signature had a good predictive ability for recurrence and prognosis. Conclusions We established a four-gene signature and predictive model to predict the recurrence and corresponding survival rates in patients with early lung adenocarcinoma after surgery. These may be helpful for reforumulating post-operative consolidation treatment strategies.
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Affiliation(s)
- Peng Han
- Department of Thoracic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Jiaqi Yue
- Department of Thoracic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Kangle Kong
- Department of Thoracic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Shan Hu
- Department of Thoracic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Peng Cao
- Department of Thoracic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Yu Deng
- Department of Thoracic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Fan Li
- Department of Thoracic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Bo Zhao
- Department of Thoracic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
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4
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Solanki AK, Arif E, Srivastava P, Furcht CM, Rahman B, Wen P, Singh A, Holzman LB, Fitzgibbon WR, Budisavljevic MN, Lobo GP, Kwon SH, Han Z, Lazzara MJ, Lipschutz JH, Nihalani D. Phosphorylation of slit diaphragm proteins NEPHRIN and NEPH1 upon binding of HGF promotes podocyte repair. J Biol Chem 2021; 297:101079. [PMID: 34391780 PMCID: PMC8429977 DOI: 10.1016/j.jbc.2021.101079] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 08/02/2021] [Accepted: 08/11/2021] [Indexed: 12/22/2022] Open
Abstract
Phosphorylation (activation) and dephosphorylation (deactivation) of the slit diaphragm proteins NEPHRIN and NEPH1 are critical for maintaining the kidney epithelial podocyte actin cytoskeleton and, therefore, proper glomerular filtration. However, the mechanisms underlying these events remain largely unknown. Here we show that NEPHRIN and NEPH1 are novel receptor proteins for hepatocyte growth factor (HGF) and can be phosphorylated independently of the mesenchymal epithelial transition receptor in a ligand-dependent fashion through engagement of their extracellular domains by HGF. Furthermore, we demonstrate SH2 domain–containing protein tyrosine phosphatase-2–dependent dephosphorylation of these proteins. To establish HGF as a ligand, purified baculovirus-expressed NEPHRIN and NEPH1 recombinant proteins were used in surface plasma resonance binding experiments. We report high-affinity interactions of NEPHRIN and NEPH1 with HGF, although NEPHRIN binding was 20-fold higher than that of NEPH1. In addition, using molecular modeling we constructed peptides that were used to map specific HGF-binding regions in the extracellular domains of NEPHRIN and NEPH1. Finally, using an in vitro model of cultured podocytes and an ex vivo model of Drosophila nephrocytes, as well as chemically induced injury models, we demonstrated that HGF-induced phosphorylation of NEPHRIN and NEPH1 is centrally involved in podocyte repair. Taken together, this is the first study demonstrating a receptor-based function for NEPHRIN and NEPH1. This has important biological and clinical implications for the repair of injured podocytes and the maintenance of podocyte integrity.
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Affiliation(s)
- Ashish K Solanki
- Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Ehtesham Arif
- Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Pankaj Srivastava
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Christopher M Furcht
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Bushra Rahman
- Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Pei Wen
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Avinash Singh
- Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Lawrence B Holzman
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Wayne R Fitzgibbon
- Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Milos N Budisavljevic
- Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Glenn P Lobo
- Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Sang-Ho Kwon
- Department of Cellular Biology and Anatomy, Augusta University, Augusta, Georgia, USA
| | - Zhe Han
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Matthew J Lazzara
- Department of Chemical Engineering, University of Virginia, Charlottesville, Virginia, USA
| | - Joshua H Lipschutz
- Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, USA; Department of Medicine, Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina, USA.
| | - Deepak Nihalani
- Division of Kidney, Urologic and Hematologic Diseases, National Institutes of Health, Bethesda, Maryland, USA
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5
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Höhfeld J, Benzing T, Bloch W, Fürst DO, Gehlert S, Hesse M, Hoffmann B, Hoppe T, Huesgen PF, Köhn M, Kolanus W, Merkel R, Niessen CM, Pokrzywa W, Rinschen MM, Wachten D, Warscheid B. Maintaining proteostasis under mechanical stress. EMBO Rep 2021; 22:e52507. [PMID: 34309183 PMCID: PMC8339670 DOI: 10.15252/embr.202152507] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 06/28/2021] [Accepted: 07/01/2021] [Indexed: 12/11/2022] Open
Abstract
Cell survival, tissue integrity and organismal health depend on the ability to maintain functional protein networks even under conditions that threaten protein integrity. Protection against such stress conditions involves the adaptation of folding and degradation machineries, which help to preserve the protein network by facilitating the refolding or disposal of damaged proteins. In multicellular organisms, cells are permanently exposed to stress resulting from mechanical forces. Yet, for long time mechanical stress was not recognized as a primary stressor that perturbs protein structure and threatens proteome integrity. The identification and characterization of protein folding and degradation systems, which handle force-unfolded proteins, marks a turning point in this regard. It has become apparent that mechanical stress protection operates during cell differentiation, adhesion and migration and is essential for maintaining tissues such as skeletal muscle, heart and kidney as well as the immune system. Here, we provide an overview of recent advances in our understanding of mechanical stress protection.
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Affiliation(s)
- Jörg Höhfeld
- Institute for Cell BiologyRheinische Friedrich‐Wilhelms University BonnBonnGermany
| | - Thomas Benzing
- Department II of Internal Medicine and Center for Molecular Medicine Cologne (CMMC)University of CologneCologneGermany
| | - Wilhelm Bloch
- Institute of Cardiovascular Research and Sports MedicineGerman Sport UniversityCologneGermany
| | - Dieter O Fürst
- Institute for Cell BiologyRheinische Friedrich‐Wilhelms University BonnBonnGermany
| | - Sebastian Gehlert
- Institute of Cardiovascular Research and Sports MedicineGerman Sport UniversityCologneGermany
- Department for the Biosciences of SportsInstitute of Sports ScienceUniversity of HildesheimHildesheimGermany
| | - Michael Hesse
- Institute of Physiology I, Life & Brain CenterMedical FacultyRheinische Friedrich‐Wilhelms UniversityBonnGermany
| | - Bernd Hoffmann
- Institute of Biological Information Processing, IBI‐2: MechanobiologyForschungszentrum JülichJülichGermany
| | - Thorsten Hoppe
- Institute for GeneticsCologne Excellence Cluster on Cellular Stress Responses in Aging‐Associated Diseases (CECAD) and CMMCUniversity of CologneCologneGermany
| | - Pitter F Huesgen
- Central Institute for Engineering, Electronics and Analytics, ZEA3Forschungszentrum JülichJülichGermany
- CECADUniversity of CologneCologneGermany
| | - Maja Köhn
- Institute of Biology IIIFaculty of Biology, and Signalling Research Centres BIOSS and CIBSSAlbert‐Ludwigs‐University FreiburgFreiburgGermany
| | - Waldemar Kolanus
- LIMES‐InstituteRheinische Friedrich‐Wilhelms University BonnBonnGermany
| | - Rudolf Merkel
- Institute of Biological Information Processing, IBI‐2: MechanobiologyForschungszentrum JülichJülichGermany
| | - Carien M Niessen
- Department of Dermatology and CECADUniversity of CologneCologneGermany
| | | | - Markus M Rinschen
- Department of Biomedicine and Aarhus Institute of Advanced StudiesAarhus UniversityAarhusDenmark
- Department of MedicineUniversity Medical Center Hamburg‐EppendorfHamburgGermany
| | - Dagmar Wachten
- Institute of Innate ImmunityUniversity Hospital BonnBonnGermany
| | - Bettina Warscheid
- Institute of Biology IIFaculty of Biology, and Signalling Research Centres BIOSS and CIBSSAlbert‐Ludwigs‐University FreiburgFreiburgGermany
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6
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Liu M, Xu Z, Zhang C, Yang C, Feng J, Lu Y, Zhang W, Chen W, Xu X, Sun X, Yang M, Liu W, Zhou T, Yang Y. NudC L279P Mutation Destabilizes Filamin A by Inhibiting the Hsp90 Chaperoning Pathway and Suppresses Cell Migration. Front Cell Dev Biol 2021; 9:671233. [PMID: 34262899 PMCID: PMC8273881 DOI: 10.3389/fcell.2021.671233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 05/31/2021] [Indexed: 11/29/2022] Open
Abstract
Filamin A, the first discovered non-muscle actin filament cross-linking protein, plays a crucial role in regulating cell migration that participates in diverse cellular and developmental processes. However, the regulatory mechanism of filamin A stability remains unclear. Here, we find that nuclear distribution gene C (NudC), a cochaperone of heat shock protein 90 (Hsp90), is required to stabilize filamin A in mammalian cells. Immunoprecipitation-mass spectrometry and western blotting analyses reveal that NudC interacts with filamin A. Overexpression of human NudC-L279P (an evolutionarily conserved mutation in NudC that impairs its chaperone activity) not only decreases the protein level of filamin A but also results in actin disorganization and the suppression of cell migration. Ectopic expression of filamin A is able to reverse these defects induced by the overexpression of NudC-L279P. Furthermore, Hsp90 forms a complex with filamin A. The inhibition of Hsp90 ATPase activity by either geldanamycin or radicicol decreases the protein stability of filamin A. In addition, ectopic expression of Hsp90 efficiently restores NudC-L279P overexpression-induced protein stability and functional defects of filamin A. Taken together, these data suggest NudC L279P mutation destabilizes filamin A by inhibiting the Hsp90 chaperoning pathway and suppresses cell migration.
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Affiliation(s)
- Min Liu
- Department of Cell Biology, and Institute of Gastroenterology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Zhangqi Xu
- Department of Cell Biology, and Institute of Gastroenterology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Cheng Zhang
- Department of Cell Biology, and Institute of Gastroenterology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Chunxia Yang
- Department of Cell Biology, and Institute of Gastroenterology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Jiaxing Feng
- Department of Cell Biology, and Institute of Gastroenterology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yiqing Lu
- Department of Cell Biology, and Institute of Gastroenterology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Wen Zhang
- Department of Cell Biology, and Institute of Gastroenterology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Wenwen Chen
- Department of Cell Biology, and Institute of Gastroenterology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Xiaoyang Xu
- Department of Cell Biology, and Institute of Gastroenterology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Xiaoxia Sun
- Department of Cell Biology, and Institute of Gastroenterology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Mingyang Yang
- Department of Cell Biology, and Institute of Gastroenterology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Wei Liu
- Department of Cell Biology, and Institute of Gastroenterology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Tianhua Zhou
- Department of Cell Biology, and Institute of Gastroenterology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,The Cancer Center of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China.,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Yuehong Yang
- Department of Cell Biology, and Institute of Gastroenterology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
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7
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Gao W, Liu Y, Fan L, Zheng B, Jefferson JR, Wang S, Zhang H, Fang X, Nguyen BV, Zhu T, Roman RJ, Fan F. Role of γ-adducin in actin cytoskeleton rearrangements in podocyte pathophysiology. Am J Physiol Renal Physiol 2021; 320:F97-F113. [PMID: 33308016 PMCID: PMC7847051 DOI: 10.1152/ajprenal.00423.2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 11/24/2020] [Accepted: 11/24/2020] [Indexed: 12/16/2022] Open
Abstract
We recently reported that the enhanced susceptibility to chronic kidney disease (CKD) in the fawn-hooded hypertensive (FHH) rat is caused, at least in part, by a mutation in γ-adducin (ADD3) that attenuates renal vascular function. The present study explored whether Add3 contributes to the modulation of podocyte structure and function using FHH and FHH.Add3 transgenic rats. The expression of ADD3 on the membrane of primary podocytes isolated from FHH was reduced compared with FHH.Add3 transgenic rats. We found that F-actin nets, which are typically localized in the lamellipodia, replaced unbranched stress fibers in conditionally immortalized mouse podocytes transfected with Add3 Dicer-substrate short interfering RNA (DsiRNA) and primary podocytes isolated from FHH rats. There were increased F/G-actin ratios and expression of the Arp2/3 complexes throughout FHH podocytes in association with reduced synaptopodin and RhoA but enhanced Rac1 and CDC42 expression in the renal cortex, glomeruli, and podocytes of FHH rats. The expression of nephrin at the slit diaphragm and the levels of focal adhesion proteins integrin-α3 and integrin-β1 were decreased in the glomeruli of FHH rats. Cell migration was enhanced and adhesion was reduced in podocytes of FHH rats as well as in immortalized mouse podocytes transfected with Add3 DsiRNA. Mean arterial pressures were similar in FHH and FHH.Add3 transgenic rats at 16 wk of age; however, FHH rats exhibited enhanced proteinuria associated with podocyte foot process effacement. These results demonstrate that reduced ADD3 function in FHH rats alters baseline podocyte pathophysiology by rearrangement of the actin cytoskeleton at the onset of proteinuria in young animals.
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Affiliation(s)
- Wenjun Gao
- Department of Urology, Zhongshan Hospital, Fudan University, Shanghai, China
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Yedan Liu
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Letao Fan
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Baoying Zheng
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Joshua R Jefferson
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Shaoxun Wang
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Huawei Zhang
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Xing Fang
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Bond V Nguyen
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Tongyu Zhu
- Department of Urology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Richard J Roman
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Fan Fan
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
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8
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Antoine M, Vandenbroere I, Ghosh S, Erneux C, Pirson I. IRSp53 is a novel interactor of SHIP2: A role of the actin binding protein Mena in their cellular localization in breast cancer cells. Cell Signal 2020; 73:109692. [PMID: 32535200 DOI: 10.1016/j.cellsig.2020.109692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 06/08/2020] [Accepted: 06/09/2020] [Indexed: 10/24/2022]
Abstract
A tight control of the machineries regulating membrane bending and actin dynamics is very important for the generation of membrane protrusions, which are crucial for cell migration and invasion. Protein/protein and protein/phosphoinositides complexes assemble and disassemble to coordinate these mechanisms, the scaffold properties of the involved proteins playing a prominent role in this organization. The PI 5-phosphatase SHIP2 is a critical enzyme modulating PI(3,4,5)P3, PI(4,5)P2 and PI(3,4)P2 content in the cell. The scaffold properties of SHIP2 contribute to the specific targeting or retention of the protein in particular subcellular domains. Here, we identified IRSp53 as a new binding interactor of SHIP2 proline-rich domain. Both proteins are costained in HEK293T cells protrusions, upon transfection. We showed that the SH3-binding polyproline motif recognized by IRSp53 in SHIP2 is different from the regions targeted by other PRR binding partners i.e., CIN85, ITSN or even Mena a common interactor of both SHIP2 and IRSp53. We presented evidence that IRSp53 phosphorylation on S366 did not influence its interaction with SHIP2 and that Mena is not necessary for the association of SHIP2 with IRSp53 in MDA-MB-231 cells. The absence of Mena in MDA-MB-231 cells decreased the intracellular content in F-actin and modified the subcellular localization of SHIP2 and IRSp53 by increasing their relative content at the plasma membrane. Together our data suggest that SHIP2, through interaction with the cell protrusion regulators IRSp53 and Mena, participate to the formation of multi-protein complexes. This ensures the appropriate modulations of PIs which is important for regulation of membrane dynamics.
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Affiliation(s)
- Mathieu Antoine
- Institut de Recherche Interdisciplinaire en Biologie Humaine et moléculaire (IRIBHM), Université Libre de Bruxelles, Campus Erasme, 1070 Brussels, Belgium.
| | - Isabelle Vandenbroere
- Institut de Recherche Interdisciplinaire en Biologie Humaine et moléculaire (IRIBHM), Université Libre de Bruxelles, Campus Erasme, 1070 Brussels, Belgium
| | - Somadri Ghosh
- Institut de Recherche Interdisciplinaire en Biologie Humaine et moléculaire (IRIBHM), Université Libre de Bruxelles, Campus Erasme, 1070 Brussels, Belgium
| | - Christophe Erneux
- Institut de Recherche Interdisciplinaire en Biologie Humaine et moléculaire (IRIBHM), Université Libre de Bruxelles, Campus Erasme, 1070 Brussels, Belgium
| | - Isabelle Pirson
- Institut de Recherche Interdisciplinaire en Biologie Humaine et moléculaire (IRIBHM), Université Libre de Bruxelles, Campus Erasme, 1070 Brussels, Belgium.
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9
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Koehler S, Kuczkowski A, Kuehne L, Jüngst C, Hoehne M, Grahammer F, Eddy S, Kretzler M, Beck BB, Höhfeld J, Schermer B, Benzing T, Brinkkoetter PT, Rinschen MM. Proteome Analysis of Isolated Podocytes Reveals Stress Responses in Glomerular Sclerosis. J Am Soc Nephrol 2020; 31:544-559. [PMID: 32047005 DOI: 10.1681/asn.2019030312] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 12/04/2019] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Understanding podocyte-specific responses to injury at a systems level is difficult because injury leads to podocyte loss or an increase of extracellular matrix, altering glomerular cellular composition. Finding a window into early podocyte injury might help identify molecular pathways involved in the podocyte stress response. METHODS We developed an approach to apply proteome analysis to very small samples of purified podocyte fractions. To examine podocytes in early disease states in FSGS mouse models, we used podocyte fractions isolated from individual mice after chemical induction of glomerular disease (with Doxorubicin or LPS). We also applied single-glomerular proteome analysis to tissue from patients with FSGS. RESULTS Transcriptome and proteome analysis of glomeruli from patients with FSGS revealed an underrepresentation of podocyte-specific genes and proteins in late-stage disease. Proteome analysis of purified podocyte fractions from FSGS mouse models showed an early stress response that includes perturbations of metabolic, mechanical, and proteostasis proteins. Additional analysis revealed a high correlation between the amount of proteinuria and expression levels of the mechanosensor protein Filamin-B. Increased expression of Filamin-B in podocytes in biopsy samples from patients with FSGS, in single glomeruli from proteinuric rats, and in podocytes undergoing mechanical stress suggests that this protein has a role in detrimental stress responses. In Drosophila, nephrocytes with reduced filamin homolog Cher displayed altered filtration capacity, but exhibited no change in slit diaphragm structure. CONCLUSIONS We identified conserved mechanisms of the podocyte stress response through ultrasensitive proteome analysis of human glomerular FSGS tissue and purified native mouse podocytes during early disease stages. This approach enables systematic comparisons of large-scale proteomics data and phenotype-to-protein correlation.
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Affiliation(s)
- Sybille Koehler
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany.,Biomedical Sciences, University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | - Alexander Kuczkowski
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Lucas Kuehne
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Christian Jüngst
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany
| | - Martin Hoehne
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany
| | - Florian Grahammer
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Eppendorf, Hamburg, Germany
| | - Sean Eddy
- Division of Nephrology, Department of Internal Medicine, and
| | - Matthias Kretzler
- Division of Nephrology, Department of Internal Medicine, and.,Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan
| | - Bodo B Beck
- Department of Human Genetics, University Hospital Cologne, Cologne, Germany
| | - Jörg Höhfeld
- Cell Biology, University of Bonn, Bonn, Germany; and
| | - Bernhard Schermer
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany
| | - Thomas Benzing
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany
| | - Paul T Brinkkoetter
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany;
| | - Markus M Rinschen
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; .,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany.,Center for Metabolomics and Mass Spectrometry, The Scripps Research Institute, La Jolla, California
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10
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Ma Y, Yang Q, Zhong Z, Liang W, Zhang L, Yang Y, Ding G. Role of c-Abl and nephrin in podocyte cytoskeletal remodeling induced by angiotensin II. Cell Death Dis 2018; 9:185. [PMID: 29416010 PMCID: PMC5833834 DOI: 10.1038/s41419-017-0225-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 12/05/2017] [Accepted: 12/06/2017] [Indexed: 12/18/2022]
Abstract
Our previous study showed that angiotensin II (Ang II) exposure diminished the interaction between nephrin and c-Abl, then c-Abl mediated SHIP2-Akt pathway in the process of podocyte injury in vivo and vitro. However, the relationship between nephrin and c-Abl was unknown. Recently, various studies showed that nephrin was required for cytoskeletal remodeling in glomerular podocytes. But its specific mechanisms remain incompletely understood. As a nonreceptor tyrosine kinase involved in cytoskeletal regulation, c-Abl may be a candidate of signaling proteins interacting with Src homology 2/3 (SH2/SH3) domains of nephrin. Therefore, it is proposed that c-Abl contributes to nephrin-dependent cytoskeletal remodeling of podocytes. Herein, we observed that nephrin-c-Abl colocalization were suppressed in glomeruli of patients with proteinuria. Next, CD16/7-nephrin and c-Abl vectors were constructed to investigate the nephrin-c-Abl signaling pathway in podocyte actin-cytoskeletal remodeling. The disorganized cytoskeleton stimulated by cytochalasin D in COS7 cells was dramatically restored by co-transfection with phosphorylated CD16/7-nephrin and c-Abl full-length constructs. Further, co-immunoprecipitation showed that phosphorylated CD16/7-nephrin interacted with wild-type c-Abl, but not with SH2/SH3-defective c-Abl. These findings suggest that phosphorylated nephrin is able to recruit c-Abl in a SH2/SH3-dependent manner and detached c-Abl from dephosphorylated nephrin contributes to cytoskeletal remodeling in podocytes.
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Affiliation(s)
- Yiqiong Ma
- Division of Nephrology, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Qian Yang
- Division of Nephrology, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Zhentong Zhong
- Division of Nephrology, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Wei Liang
- Division of Nephrology, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Lu Zhang
- Division of Nephrology, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Yingjie Yang
- Division of Nephrology, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Guohua Ding
- Division of Nephrology, Renmin Hospital of Wuhan University, Wuhan, 430060, China.
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11
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Ramos AR, Elong Edimo W, Erneux C. Phosphoinositide 5-phosphatase activities control cell motility in glioblastoma: Two phosphoinositides PI(4,5)P2 and PI(3,4)P2 are involved. Adv Biol Regul 2018; 67:40-48. [PMID: 28916189 DOI: 10.1016/j.jbior.2017.09.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 09/01/2017] [Accepted: 09/01/2017] [Indexed: 05/15/2023]
Abstract
Inositol polyphosphate 5-phosphatases or phosphoinositide 5-phosphatases (PI 5-phosphatases) are enzymes that can act on soluble inositol phosphates and/or phosphoinositides (PIs). Several PI 5-phosphatases have been linked to human genetic diseases, in particular the Lowe protein or OCRL which is mutated in the Lowe syndrome. There are 10 different members of this family and 9 of them can use PIs as substrate. One of these substrates, PI(3,4,5)P3 binds to specific PH domains and recruits as effectors specific proteins to signaling complexes. Protein kinase B is one target protein and activation of the kinase will have a major impact on cell proliferation, survival and cell metabolism. Two other PIs, PI(4,5)P2 and PI(3,4)P2, are produced or used as substrates of PI 5-phosphatases (OCRL, INPP5B, SHIP1/2, SYNJ1/2, INPP5K, INPP5J, INPP5E). The inositol lipids may influence many aspects of cytoskeletal organization, lamellipodia formation and F-actin polymerization. PI 5-phosphatases have been reported to control cell migration, adhesion, polarity and cell invasion particularly in cancer cells. In glioblastoma, reducing SHIP2 expression can positively or negatively affect the speed of cell migration depending on the glioblastoma cell type. The two PI 5-phosphatases SHIP2 or SKIP could be localized at the plasma membrane and can reduce either PI(3,4,5)P3 or PI(4,5)P2 abundance. In the glioblastoma 1321 N1 cells, SHIP2 controls plasma membrane PI(4,5)P2 thereby participating in the control of cell migration.
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Affiliation(s)
- Ana Raquel Ramos
- Interdisciplinary Research Institute (IRIBHM), Université Libre de Bruxelles, Campus Erasme, Bldg C, 808 Route de Lennik, 1070 Brussels, Belgium
| | - William's Elong Edimo
- Interdisciplinary Research Institute (IRIBHM), Université Libre de Bruxelles, Campus Erasme, Bldg C, 808 Route de Lennik, 1070 Brussels, Belgium
| | - Christophe Erneux
- Interdisciplinary Research Institute (IRIBHM), Université Libre de Bruxelles, Campus Erasme, Bldg C, 808 Route de Lennik, 1070 Brussels, Belgium.
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12
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Martin CE, Jones N. Nephrin Signaling in the Podocyte: An Updated View of Signal Regulation at the Slit Diaphragm and Beyond. Front Endocrinol (Lausanne) 2018; 9:302. [PMID: 29922234 PMCID: PMC5996060 DOI: 10.3389/fendo.2018.00302] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 05/22/2018] [Indexed: 12/11/2022] Open
Abstract
Podocytes are a major component of the glomerular blood filtration barrier, and alterations to the morphology of their unique actin-based foot processes (FP) are a common feature of kidney disease. Adjacent FP are connected by a specialized intercellular junction known as the slit diaphragm (SD), which serves as the ultimate barrier to regulate passage of macromolecules from the blood. While the link between SD dysfunction and reduced filtration selectivity has been recognized for nearly 50 years, our understanding of the underlying molecular circuitry began only 20 years ago, sparked by the identification of NPHS1, encoding the transmembrane protein nephrin. Nephrin not only functions as the core component of the extracellular SD filtration network but also as a signaling scaffold via interactions at its short intracellular region. Phospho-regulation of several conserved tyrosine residues in this region influences signal transduction pathways which control podocyte cell adhesion, shape, and survival, and emerging studies highlight roles for nephrin phospho-dynamics in mechanotransduction and endocytosis. The following review aims to summarize the last 5 years of advancement in our knowledge of how signaling centered at nephrin directs SD barrier formation and function. We further provide insight on promising frontiers in podocyte biology, which have implications for SD signaling in the healthy and diseased kidney.
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13
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14
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ARF6 mediates nephrin tyrosine phosphorylation-induced podocyte cellular dynamics. PLoS One 2017; 12:e0184575. [PMID: 28880939 PMCID: PMC5589247 DOI: 10.1371/journal.pone.0184575] [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: 05/22/2017] [Accepted: 08/26/2017] [Indexed: 01/10/2023] Open
Abstract
ADP-ribosylation factor 6 (ARF6) is a small GTPase necessary for regulating cellular structure, motility, and vesicle trafficking. In several cellular systems, ARF6 was shown to regulate actin dynamics in coordination with Rac1, a Rho small GTPase. We examined the function of ARF6 in the kidney podocyte because Rac1 was implicated in kidney diseases involving this cell. We found that ARF6 expression was enriched in human podocytes and that it modulated podocyte cytoskeletal dynamics through a functional interaction with nephrin, an intercellular junction protein necessary for podocyte injury-induced signaling requiring activation by tyrosine phosphorylation of its cytoplasmic domain. ARF6 was necessary for nephrin activation-induced ruffling and focal adhesion turnover, possibly by altering Rac1 activity. In podocyte-specific Arf6 (ARF6_PodKO) knockout mice, ARF6 deficiency did not result in a spontaneous kidney developmental phenotype or proteinuria after aging. However, ARF6_PodKO mice exhibited distinct phenotypes in two in vivo glomerular injury models. In the protamine sulfate perfusion model, which induced acute podocyte effacement, ARF6_PodKO mice were protected from podocyte effacement. In the nephrotoxic serum nephritis model, which induced immune-complex mediated injury, ARF6_PodKO mice exhibited aggravated proteinuria. Together, these observations suggest that while ARF6 is necessary for nephrin tyrosine phosphorylation-induced cytoskeletal dynamics in cultured podocytes, ARF6 has pleotropic podocyte roles in vivo, where glomerular injury-specific mechanisms might activate distinct signaling pathways that dictate whether ARF6 activity is beneficial or deleterious for maintaining the integrity of the glomerular filtration barrier.
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15
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Endlich K, Kliewe F, Endlich N. Stressed podocytes-mechanical forces, sensors, signaling and response. Pflugers Arch 2017; 469:937-949. [PMID: 28687864 DOI: 10.1007/s00424-017-2025-8] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 06/22/2017] [Indexed: 02/07/2023]
Abstract
Increased glomerular capillary pressure (glomerular hypertension) and increased glomerular filtration rate (glomerular hyperfiltration) have been proven to cause glomerulosclerosis in animal models and are likely to be operative in patients. Since podocytes cover the glomerular basement membrane, they are exposed to tensile stress due to circumferential wall tension and to fluid shear stress arising from filtrate flow through the narrow filtration slits and through Bowman's space. In vitro evidence documents that podocytes respond to tensile stress as well as to fluid shear stress. Several proteins are discussed in this review that are expressed in podocytes and could act as mechanosensors converting mechanical force via a conformational change into a biochemical signal. The cation channels P2X4 and TRPC6 were shown to be involved in mechanosignaling in podocytes. P2X4 is activated by stretch-induced ATP release, while TRPC6 might be inherently mechanosensitive. Membrane, slit diaphragm and cell-matrix contact proteins are connected to the sublemmal actin network in podocytes via various linker proteins. Therefore, actin-associated proteins, like the proven mechanosensor filamin, are ideal candidates to sense forces in the podocyte cytoskeleton. Furthermore, podocytes express talin, p130Cas, and fibronectin that are known to undergo a conformational change in response to mechanical force exposing cryptic binding sites. Downstream of mechanosensors, experimental evidence suggests the involvement of MAP kinases, Ca2+ and COX2 in mechanosignaling and an emerging role of YAP/TAZ. In summary, our understanding of mechanotransduction in podocytes is still sketchy, but future progress holds promise to identify targets to alleviate conditions of increased mechanical load.
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Affiliation(s)
- Karlhans Endlich
- Department of Anatomy and Cell Biology, University Medicine Greifswald, 17489, Greifswald, Germany.
- Institut für Anatomie and Zellbiologie, Universitätsmedizin Greifswald, Friedrich-Loeffler-Str. 23c, 17489, Greifswald, Germany.
| | - Felix Kliewe
- Department of Anatomy and Cell Biology, University Medicine Greifswald, 17489, Greifswald, Germany
| | - Nicole Endlich
- Department of Anatomy and Cell Biology, University Medicine Greifswald, 17489, Greifswald, Germany
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16
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Abstract
Podocytes, the postmitotic and highly branched epithelial cells of the glomerulus, play a pivotal role for the function of the glomerular filtration barrier and the development of chronic kidney disease. It has long been discussed whether podocytes in vivo are motile and can laterally migrate in a coordinated way along the capillaries until they reach the position of naked glomerular basement membrane often found in podocytopathies. Such motility would also be the prerequisite for the replacement of lost podocytes by progenitor cells. Additionally, the change of the podocyte foot processes from a normal to an effaced morphology, like it is found in many kidney diseases, would require a dynamic behavior of podocytes. Since the actin cytoskeleton is expressed in podocytes in vitro and in vivo and the morphology of podocytes is highly dependent on actin, actin-associated, and actin-regulating proteins, it was assumed that podocytes are dynamic and motile. After earlier technical limitations had been overcome and novel microscopic techniques like multiphoton microscopy had been developed, it became possible to continuously study the behavior of podocytes in living rodents and zebrafish larvae under physiological and pathological conditions. Recent in vivo microscopic studies in different model organisms suggest that lateral migration of podocytes in situ is a very unlikely event and only dynamic apical cell protrusions can be observed under pathological conditions. This review discusses recent findings concerning different forms of motility (like lateral translocative (LTM), apical translocative (ATM), and stationary motility (SM)) and their role for podocytopathies.
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Affiliation(s)
- Nicole Endlich
- Department of Anatomy and Cell Biology, University Medicine Greifswald, 17487, Greifswald, Germany. .,Institut für Anatomie und Zellbiologie, Universitätsmedizin Greifswald, Friedrich-Loeffler-Str. 23c, 17487, Greifswald, Germany.
| | - Florian Siegerist
- Department of Anatomy and Cell Biology, University Medicine Greifswald, 17487, Greifswald, Germany
| | - Karlhans Endlich
- Department of Anatomy and Cell Biology, University Medicine Greifswald, 17487, Greifswald, Germany
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17
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Thomas MP, Erneux C, Potter BVL. SHIP2: Structure, Function and Inhibition. Chembiochem 2017; 18:233-247. [DOI: 10.1002/cbic.201600541] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Indexed: 11/10/2022]
Affiliation(s)
- Mark P. Thomas
- Department of Pharmacy and Pharmacology; University of Bath; Claverton Down Bath BA2 7AY UK
| | - Christophe Erneux
- I.R.I.B.H.M.; Université Libre de Bruxelles; Campus Erasme 808 Route de Lennik 1070 Brussels Belgium
| | - Barry V. L. Potter
- Drug Discovery and Medicinal Chemistry; Department of Pharmacology; University of Oxford; Mansfield Road Oxford OX1 3QT UK
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18
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The SHIP2 interactor Myo1c is required for cell migration in 1321 N1 glioblastoma cells. Biochem Biophys Res Commun 2016; 476:508-514. [DOI: 10.1016/j.bbrc.2016.05.154] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 05/28/2016] [Indexed: 12/29/2022]
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19
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Verma R, Venkatareddy M, Kalinowski A, Patel SR, Garg P. Integrin Ligation Results in Nephrin Tyrosine Phosphorylation In Vitro. PLoS One 2016; 11:e0148906. [PMID: 26848974 PMCID: PMC4743922 DOI: 10.1371/journal.pone.0148906] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 01/24/2016] [Indexed: 11/19/2022] Open
Abstract
Nephrin is expressed at the basolateral aspect of podocytes and is an important signaling protein at the glomerular slit diaphragm. In vitro studies have demonstrated that Nephrin phosphorylation-dependent signaling is able to assemble a protein complex that is able to polymerize actin. However, proximal signaling events that result in nephrin tyrosine phosphorylation are not well understood. Nephrin deletion in mice and human nephrin mutations result in developmental failure of the podocyte intercellular junction resutling in proteinuria. This has been presumed to be due to a failure to respond to an external polarized cue in the absence of nephrin or a failure to transduce an outside-in signal in patients with nephrin mutations. The nephrin extracellular domain binds to itself or neph1 across the foot process intercellular junction. Nephrin is tyrosine phosphorylation-silent in healthy glomeruli when presumably the nephrin extracellular domain is in an engaged state. These observations raise the possibility of an alternate proximal signaling mechanism that might be responsible for nephrin tyrosine phosphorylation. Here we present data showing that integrin engagement at the basal aspect of cultured podocytes results in nephrin tyrosine phosphorylation. This is abrogated by incubating podocytes with an antibody that prevents integrin β1 ligation and activation in response to binding to extracellular matrix. Furthermore, nephrin tyrosine phosphorylation was observed in podocytes expressing a membrane-targeted nephrin construct that lacks the extracellular domain. We propose, integrin-activation based signaling might be responsible for nephrin phosphorylation rather than engagment of the nephrin extracellular domain by a ligand.
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Affiliation(s)
- Rakesh Verma
- Division of Nephroloigy, Department of Internal Medicine, University of Michigan School of Medicine, Ann Arbor, Michigan, United States of America
| | - Madhusudan Venkatareddy
- Division of Nephroloigy, Department of Internal Medicine, University of Michigan School of Medicine, Ann Arbor, Michigan, United States of America
| | - Anne Kalinowski
- Division of Nephroloigy, Department of Internal Medicine, University of Michigan School of Medicine, Ann Arbor, Michigan, United States of America
| | - Sanjeevkumar R. Patel
- Division of Nephroloigy, Department of Internal Medicine, University of Michigan School of Medicine, Ann Arbor, Michigan, United States of America
| | - Puneet Garg
- Division of Nephroloigy, Department of Internal Medicine, University of Michigan School of Medicine, Ann Arbor, Michigan, United States of America
- * E-mail:
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20
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Venkatareddy M, Verma R, Kalinowski A, Patel SR, Shisheva A, Garg P. Distinct Requirements for Vacuolar Protein Sorting 34 Downstream Effector Phosphatidylinositol 3-Phosphate 5-Kinase in Podocytes Versus Proximal Tubular Cells. J Am Soc Nephrol 2016; 27:2702-19. [PMID: 26825532 DOI: 10.1681/asn.2015050555] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 12/09/2015] [Indexed: 12/16/2022] Open
Abstract
The mechanisms by which the glomerular filtration barrier prevents the loss of large macromolecules and simultaneously, maintains the filter remain poorly understood. Recent studies proposed that podocytes have an active role in both the endocytosis of filtered macromolecules and the maintenance of the filtration barrier. Deletion of a key endosomal trafficking regulator, the class 3 phosphatidylinositol (PtdIns) 3-kinase vacuolar protein sorting 34 (Vps34), in podocytes results in aberrant endosomal membrane morphology and podocyte dysfunction. We recently showed that the vacuolation phenotype in cultured Vps34-deficient podocytes is caused by the absence of a substrate for the Vps34 downstream effector PtdIns 3-phosphate 5-kinase (PIKfyve), which phosphorylates Vps34-generated PtdIns(3)P to produce PtdIns (3,5)P2. PIKfyve perturbation and PtdIns(3,5)P2 reduction result in massive membrane vacuolation along the endosomal system, but the cell-specific functions of PIKfyve in vivo remain unclear. We show here that the genetic deletion of PIKfyve in endocytically active proximal tubular cells resulted in the development of large cytoplasmic vacuoles caused by arrested endocytic traffic progression at a late-endosome stage. In contrast, deletion of PIKfyve in glomerular podocytes did not significantly alter the endosomal morphology, even in age 18-month-old mice. However, on culturing, the PIKfyve-deleted podocytes developed massive cytoplasmic vacuoles. In summary, these data suggest that glomerular podocytes and proximal tubules have different requirements for PIKfyve function, likely related to distinct in vivo needs for endocytic flux.
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Affiliation(s)
- Madhusudan Venkatareddy
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan; and
| | - Rakesh Verma
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan; and
| | - Anne Kalinowski
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan; and
| | - Sanjeevkumar R Patel
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan; and
| | - Assia Shisheva
- Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan
| | - Puneet Garg
- Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan; and
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21
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Edimo WE, Ghosh S, Derua R, Janssens V, Waelkens E, Vanderwinden JM, Robe P, Erneux C. SHIP2 controls plasma membrane PI(4,5)P2 thereby participating in the control of cell migration in 1321 N1 glioblastoma. J Cell Sci 2016; 129:1101-14. [DOI: 10.1242/jcs.179663] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 01/25/2016] [Indexed: 12/31/2022] Open
Abstract
Phosphoinositides, particularly PI(3,4,5)P3, and PI(4,5)P2, are recognized by SHIP2 a member of the inositol polyphosphate 5-phosphatase family. SHIP2 dephosphorylates PI(3,4,5)P3 to form PI(3,4)P2; the latter interacts with specific target proteins (e.g. lamellipodin). Although the SHIP2 preferred substrate is PI(3,4,5)P3, PI(4,5)P2 could also be dephosphorylated to PI4P. Through depletion of SHIP2 in a glioblastoma cell line 1321 N1 cells, we show that SHIP2 inhibits cell migration. In different glioblastoma cell lines and primary cultures, SHIP2 staining at the plasma membrane partly overlaps with PI(4,5)P2 immunoreactivity. PI(4,5)P2 was upregulated in SHIP2-deficient N1 cells as compared to control cells; in contrast, PI4P was very much decreased in SHIP2-deficient cells. Therefore, SHIP2 controls both PI(3,4,5)P3 and PI(4,5)P2 levels in intact cells. In N1 cells, the PI(4,5)P2 binding protein myosin-1c was identified as a new interactor of SHIP2. Regulation of PI(4,5)P2 and PI4P content by SHIP2 controls N1 cell migration through the organization of focal adhesions. Thus, our results reveal a novel role of SHIP2 in the control of PI(4,5)P2, PI4P and cell migration in PTEN-deficient glioblastoma N1 cells.
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Affiliation(s)
- William's Elong Edimo
- IRIBHM, Campus Erasme, ULB Bâtiment C, 808 route de Lennik B-1070 Bruxelles, Belgium
| | - Somadri Ghosh
- IRIBHM, Campus Erasme, ULB Bâtiment C, 808 route de Lennik B-1070 Bruxelles, Belgium
| | - Rita Derua
- Protein Phosphorylation & Proteomics Lab, Department of Cellular and Molecular Medicine, Faculty of Medicine, KU Leuven, Herestraat 49 PO-box 901, B-3000 Leuven, Belgium
| | - Veerle Janssens
- Protein Phosphorylation & Proteomics Lab, Department of Cellular and Molecular Medicine, Faculty of Medicine, KU Leuven, Herestraat 49 PO-box 901, B-3000 Leuven, Belgium
| | - Etienne Waelkens
- Protein Phosphorylation & Proteomics Lab, Department of Cellular and Molecular Medicine, Faculty of Medicine, KU Leuven, Herestraat 49 PO-box 901, B-3000 Leuven, Belgium
| | - Jean-Marie Vanderwinden
- Laboratory of Neurophysiology, ULB Bâtiment C, 808 route de Lennik B-1070 Bruxelles, Belgium
| | - Pierre Robe
- Génétique Humaine, GIGA center, Ulg, Belgium
| | - Christophe Erneux
- IRIBHM, Campus Erasme, ULB Bâtiment C, 808 route de Lennik B-1070 Bruxelles, Belgium
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22
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Li H, Wu X, Hou S, Malek M, Kielkowska A, Noh E, Makondo KJ, Du Q, Wilkins JA, Johnston JB, Gibson SB, Lin F, Marshall AJ. Phosphatidylinositol-3,4-Bisphosphate and Its Binding Protein Lamellipodin Regulate Chemotaxis of Malignant B Lymphocytes. THE JOURNAL OF IMMUNOLOGY 2015; 196:586-95. [DOI: 10.4049/jimmunol.1500630] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 11/16/2015] [Indexed: 01/14/2023]
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23
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Shp2 Associates with and Enhances Nephrin Tyrosine Phosphorylation and Is Necessary for Foot Process Spreading in Mouse Models of Podocyte Injury. Mol Cell Biol 2015; 36:596-614. [PMID: 26644409 DOI: 10.1128/mcb.00956-15] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 11/24/2015] [Indexed: 11/20/2022] Open
Abstract
In most forms of glomerular diseases, loss of size selectivity by the kidney filtration barrier is associated with changes in the morphology of podocytes. The kidney filtration barrier is comprised of the endothelial lining, the glomerular basement membrane, and the podocyte intercellular junction, or slit diaphragm. The cell adhesion proteins nephrin and neph1 localize to the slit diaphragm and transduce signals in a Src family kinase Fyn-mediated tyrosine phosphorylation-dependent manner. Studies in cell culture suggest nephrin phosphorylation-dependent signaling events are primarily involved in regulation of actin dynamics and lamellipodium formation. Nephrin phosphorylation is a proximal event that occurs both during development and following podocyte injury. We hypothesized that abrogation of nephrin phosphorylation following injury would prevent nephrin-dependent actin remodeling and foot process morphological changes. Utilizing a biased screening approach, we found nonreceptor Src homology 2 (sh2) domain-containing phosphatase Shp2 to be associated with phosphorylated nephrin. We observed an increase in nephrin tyrosine phosphorylation in the presence of Shp2 in cell culture studies. In the human glomerulopathies minimal-change nephrosis and membranous nephropathy, there is an increase in Shp2 phosphorylation, a marker of increased Shp2 activity. Mouse podocytes lacking Shp2 do not develop foot process spreading when subjected to podocyte injury in vivo using protamine sulfate or nephrotoxic serum (NTS). In the NTS model, we observed a lack of foot process spreading in mouse podocytes with Shp2 deleted and smaller amounts of proteinuria. Taken together, these results suggest that Shp2-dependent signaling events are necessary for changes in foot process structure and function following injury.
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Yang Q, Ma Y, Liu Y, Liang W, Chen X, Ren Z, Wang H, Singhal PC, Ding G. Angiotensin II down-regulates nephrin-Akt signaling and induces podocyte injury: roleof c-Abl. Mol Biol Cell 2015; 27:197-208. [PMID: 26510503 PMCID: PMC4694757 DOI: 10.1091/mbc.e15-04-0223] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 10/23/2015] [Indexed: 11/17/2022] Open
Abstract
Ang II plays a vital role in the initiation and progression of proteinuric kidney diseases, but the mechanism is still elusive. It is shown that c-Abl is a molecular chaperone of nephrin signaling and the SHIP2-Akt pathway, and released c-Abl from nephrin is involved in Ang II–induced podocyte injury. Recent studies have shown that nephrin plays a vital role in angiotensin II (Ang II)–induced podocyte injury and thus contributes to the onset of proteinuria and the progression of renal diseases, but its specific mechanism remains unclear. c-Abl is an SH2/SH3 domain–containing nonreceptor tyrosine kinase that is involved in cell survival and regulation of the cytoskeleton. Phosphorylated nephrin is able to interact with molecules containing SH2/SH3 domains, suggesting that c-Abl may be a downstream molecule of nephrin signaling. Here we report that Ang II–infused rats developed proteinuria and podocyte damage accompanied by nephrin dephosphorylation and minimal interaction between nephrin and c-Abl. In vitro, Ang II induced podocyte injury and nephrin and Akt dephosphorylation, which occurred in tandem with minimal interaction between nephrin and c-Abl. Moreover, Ang II promoted c-Abl phosphorylation and interaction between c-Abl and SH2 domain–containing 5′-inositol phosphatase 2 (SHIP2). c-Abl small interfering RNA (siRNA) and STI571 (c-Abl inhibitor) provided protection against Ang II–induced podocyte injury, suppressed the Ang II-induced c-Abl–SHIP2 interaction and SHIP2 phosphorylation, and maintained a stable level of nephrin phosphorylation. These results indicate that c-Abl is a molecular chaperone of nephrin signaling and the SHIP2-Akt pathway and that the released c-Abl contributes to Ang II–induced podocyte injury.
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Affiliation(s)
- Qian Yang
- Division of Nephrology, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, China
| | - Yiqiong Ma
- Division of Nephrology, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, China
| | - Yipeng Liu
- Division of Nephrology, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, China
| | - Wei Liang
- Division of Nephrology, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, China
| | - Xinghua Chen
- Division of Nephrology, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, China
| | - Zhilong Ren
- Division of Nephrology, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, China
| | - Huiming Wang
- Division of Nephrology, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, China
| | - Pravin C Singhal
- Renal Molecular Research Laboratory, Feinstein Institute for Medical Research, Hofstra North Shore-Long Island Medical School, Great Neck, NY 11021
| | - Guohua Ding
- Division of Nephrology, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, China
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Phosphatidylinositol (3,4) bisphosphate-specific phosphatases and effector proteins: A distinct branch of PI3K signaling. Cell Signal 2015; 27:1789-98. [DOI: 10.1016/j.cellsig.2015.05.013] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 05/16/2015] [Accepted: 05/20/2015] [Indexed: 01/22/2023]
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Kapodistria K, Tsilibary EP, Politis P, Moustardas P, Charonis A, Kitsiou P. Nephrin, a transmembrane protein, is involved in pancreatic beta-cell survival signaling. Mol Cell Endocrinol 2015; 400:112-28. [PMID: 25448064 DOI: 10.1016/j.mce.2014.11.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 10/15/2014] [Accepted: 11/03/2014] [Indexed: 01/15/2023]
Abstract
Nephrin, a cell surface signaling receptor, regulates podocyte function in health and disease. We study the role of nephrin in β-cell survival signaling. We report that in mouse islet β-cells and the mouse pancreatic beta-cell line (βTC-6 cells) nephrin is associated and partly co-localized with PI3-kinase. Incubation of cells with functional anti-nephrin antibodies induced nephrin clustering at the plasma membrane, nephrin phosphorylation and recruitment of PI3-kinase to nephrin thus resulting in increased PI3K-dependent Akt phosphorylation and augmented phosphorylation/inhibition of pro-apoptotic Bad and FoxO. Nephrin silencing abolished Akt activation and increased susceptibility of cells to apoptosis. High glucose impaired nephrin signaling, increased nephrin internalization and up-regulated PKCα expression. Interestingly, a marked decrease in nephrin expression and phosphorylated Akt was observed in pancreatic islets of db/db lepr-/- diabetic mice. Our findings revealed that nephrin is involved in β-cell survival and suggest that glucose-induced changes in nephrin signaling may contribute to gradual pancreatic β-cell loss in type 2 diabetes.
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Affiliation(s)
- Katerina Kapodistria
- Institute of Biosciences and Applications, National Centre for Scientific Research, N.C.S.R. "Demokritos", Terma Patriarchou Grigoriou & Neapoleos, 15310 Agia Paraskevi, Attiki, Greece
| | - Effie-Photini Tsilibary
- Institute of Biosciences and Applications, National Centre for Scientific Research, N.C.S.R. "Demokritos", Terma Patriarchou Grigoriou & Neapoleos, 15310 Agia Paraskevi, Attiki, Greece
| | - Panagiotis Politis
- Center for Basic Research, Biomedical Research Foundation Academy of Athens (BRFAA), 4 Soranou Ephessiou, Athens 115 27, Greece
| | - Petros Moustardas
- Center for Clinical, Experimental Surgery and Translational Research, Biomedical Research Foundation Academy of Athens (BRFAA), 4 Soranou Ephessiou, Athens 115 27, Greece
| | - Aristidis Charonis
- Center for Clinical, Experimental Surgery and Translational Research, Biomedical Research Foundation Academy of Athens (BRFAA), 4 Soranou Ephessiou, Athens 115 27, Greece
| | - Paraskevi Kitsiou
- Institute of Biosciences and Applications, National Centre for Scientific Research, N.C.S.R. "Demokritos", Terma Patriarchou Grigoriou & Neapoleos, 15310 Agia Paraskevi, Attiki, Greece.
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Suzuki OT, Frick A, Parks BB, Trask OJ, Butz N, Steffy B, Chan E, Scoville DK, Healy E, Benton C, McQuaid PE, Thomas RS, Wiltshire T. A cellular genetics approach identifies gene-drug interactions and pinpoints drug toxicity pathway nodes. Front Genet 2014; 5:272. [PMID: 25221565 PMCID: PMC4148776 DOI: 10.3389/fgene.2014.00272] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Accepted: 07/24/2014] [Indexed: 12/03/2022] Open
Abstract
New approaches to toxicity testing have incorporated high-throughput screening across a broad-range of in vitro assays to identify potential key events in response to chemical or drug treatment. To date, these approaches have primarily utilized repurposed drug discovery assays. In this study, we describe an approach that combines in vitro screening with genetic approaches for the experimental identification of genes and pathways involved in chemical or drug toxicity. Primary embryonic fibroblasts isolated from 32 genetically-characterized inbred mouse strains were treated in concentration-response format with 65 compounds, including pharmaceutical drugs, environmental chemicals, and compounds with known modes-of-action. Integrated cellular responses were measured at 24 and 72 h using high-content imaging and included cell loss, membrane permeability, mitochondrial function, and apoptosis. Genetic association analysis of cross-strain differences in the cellular responses resulted in a collection of candidate loci potentially underlying the variable strain response to each chemical. As a demonstration of the approach, one candidate gene involved in rotenone sensitivity, Cybb, was experimentally validated in vitro and in vivo. Pathway analysis on the combined list of candidate loci across all chemicals identified a number of over-connected nodes that may serve as core regulatory points in toxicity pathways.
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Affiliation(s)
- Oscar T Suzuki
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy at the University of North Carolina at Chapel Hill Chapel Hill, NC, USA
| | - Amber Frick
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy at the University of North Carolina at Chapel Hill Chapel Hill, NC, USA
| | - Bethany B Parks
- The Hamner Institutes for Health Sciences, Research Triangle Park NC, USA
| | - O Joseph Trask
- The Hamner Institutes for Health Sciences, Research Triangle Park NC, USA
| | - Natasha Butz
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy at the University of North Carolina at Chapel Hill Chapel Hill, NC, USA
| | - Brian Steffy
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy at the University of North Carolina at Chapel Hill Chapel Hill, NC, USA
| | - Emmanuel Chan
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy at the University of North Carolina at Chapel Hill Chapel Hill, NC, USA
| | - David K Scoville
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy at the University of North Carolina at Chapel Hill Chapel Hill, NC, USA
| | - Eric Healy
- The Hamner Institutes for Health Sciences, Research Triangle Park NC, USA
| | - Cristina Benton
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy at the University of North Carolina at Chapel Hill Chapel Hill, NC, USA
| | | | - Russell S Thomas
- The Hamner Institutes for Health Sciences, Research Triangle Park NC, USA
| | - Tim Wiltshire
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy at the University of North Carolina at Chapel Hill Chapel Hill, NC, USA
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Discovery of new glomerular disease-relevant genes by translational profiling of podocytes in vivo. Kidney Int 2014; 86:1116-29. [PMID: 24940801 PMCID: PMC4245460 DOI: 10.1038/ki.2014.204] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Revised: 04/08/2014] [Accepted: 04/24/2014] [Indexed: 12/25/2022]
Abstract
Identifying new biomarkers and therapeutic targets for podocytopathies such as focal segmental glomerulosclerosis (FSGS) requires a detailed analysis of transcriptional changes in podocytes over the course of disease. Here we used translating ribosome affinity purification (TRAP) to isolate and profile podocyte-specific mRNA in two different models of FSGS. Expressed eGFP-tagged ribosomal protein L10a in podocytes under the control of the Collagen-1α1 promoter enabled podocyte-specific mRNA isolation in a one-step process over the course of disease. This TRAP protocol robustly enriched known podocyte-specific mRNAs. We crossed col1α1-L10a mice with the actn4−/− and actn4+/K256E models of FSGS and analyzed podocyte transcriptional profiles at 2, 6 and 44 weeks of age. Two upregulated podocyte genes in murine FSGS (CXCL1 and DMPK) were found to be upregulated at the protein level in biopsies from patients with FSGS, validating this approach. There was no dilution of podocyte-specific transcripts during disease. These are the first podocyte-specific RNA expression datasets during aging and in two models of FSGS. This approach identified new podocyte proteins that are upregulated in FSGS and help define novel biomarkers and therapeutic targets for human glomerular disease.
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Abstract
Nephrotic syndrome (NS) is characterized by heavy proteinuria, hypoalbuminemia, and edema. The underlying causes of NS are diverse and are tied to inheritable and environmental factors. A common diagnostic marker for NS is effacement of podocyte foot processes. The formation and maintenance of foot processes are under the control of many signalling molecules including Rho-GTPases. Our knowledge of Rho-GTPases is based largely on the functions of three prototypic members: RhoA, Rac1, and Cdc42. In the event of podocyte injury, the rearrangement to the actin cytoskeleton is orchestrated largely by this family of proteins. The importance of maintaining proper actin dynamics in podocytes has led to much investigation as to how Rho-GTPases and their regulatory molecules form and maintain foot processes as a critical component of the kidney’s filtration barrier. Modern sequencing techniques have allowed for the identification of novel disease causing mutations in genes such as ARHGDIA, encoding Rho-GDIα. Continued use of whole exome sequencing has the potential to lead to the identification of new mutations in genes encoding Rho-GTPases or their regulatory proteins. Expanding our knowledge of the dynamic regulation of the actin network by Rho-GTPases in podocytes will pave the way for effective therapeutic options for NS patients.
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31
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Deneubourg L, Elong Edimo W, Moreau C, Vanderwinden JM, Erneux C. Phosphorylated SHIP2 on Y1135 localizes at focal adhesions and at the mitotic spindle in cancer cell lines. Cell Signal 2014; 26:1193-203. [DOI: 10.1016/j.cellsig.2014.02.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 01/20/2014] [Accepted: 02/13/2014] [Indexed: 11/30/2022]
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Rinschen MM, Wu X, König T, Pisitkun T, Hagmann H, Pahmeyer C, Lamkemeyer T, Kohli P, Schnell N, Schermer B, Dryer S, Brooks BR, Beltrao P, Krueger M, Brinkkoetter PT, Benzing T. Phosphoproteomic analysis reveals regulatory mechanisms at the kidney filtration barrier. J Am Soc Nephrol 2014; 25:1509-22. [PMID: 24511133 DOI: 10.1681/asn.2013070760] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Diseases of the kidney filtration barrier are a leading cause of ESRD. Most disorders affect the podocytes, polarized cells with a limited capacity for self-renewal that require tightly controlled signaling to maintain their integrity, viability, and function. Here, we provide an atlas of in vivo phosphorylated, glomerulus-expressed proteins, including podocyte-specific gene products, identified in an unbiased tandem mass spectrometry-based approach. We discovered 2449 phosphorylated proteins corresponding to 4079 identified high-confidence phosphorylated residues and performed a systematic bioinformatics analysis of this dataset. We discovered 146 phosphorylation sites on proteins abundantly expressed in podocytes. The prohibitin homology domain of the slit diaphragm protein podocin contained one such site, threonine 234 (T234), located within a phosphorylation motif that is mutated in human genetic forms of proteinuria. The T234 site resides at the interface of podocin dimers. Free energy calculation through molecular dynamic simulations revealed a role for T234 in regulating podocin dimerization. We show that phosphorylation critically regulates formation of high molecular weight complexes and that this may represent a general principle for the assembly of proteins containing prohibitin homology domains.
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Affiliation(s)
- Markus M Rinschen
- Department of Internal Medicine II, Center for Molecular Medicine, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, Systems Biology of Ageing Cologne
| | - Xiongwu Wu
- Laboratory of Computational Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Tim König
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases,Institute for Genetics, University of Cologne, Cologne, Germany
| | - Trairak Pisitkun
- Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Henning Hagmann
- Department of Internal Medicine II, Center for Molecular Medicine
| | | | - Tobias Lamkemeyer
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases
| | - Priyanka Kohli
- Department of Internal Medicine II, Center for Molecular Medicine, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases
| | - Nicole Schnell
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases
| | - Bernhard Schermer
- Department of Internal Medicine II, Center for Molecular Medicine, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, Systems Biology of Ageing Cologne
| | - Stuart Dryer
- Department of Biology and Biochemistry, University of Houston, Houston, Texas; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases
| | - Bernard R Brooks
- Laboratory of Computational Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Pedro Beltrao
- European Molecular Biology Laboratory-European Bioinformatics Institute, Hinxton, Cambridge, United Kingdom; and
| | - Marcus Krueger
- Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | | | - Thomas Benzing
- Department of Internal Medicine II, Center for Molecular Medicine, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, Systems Biology of Ageing Cologne,
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33
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Elong Edimo W, Schurmans S, Roger PP, Erneux C. SHIP2 signaling in normal and pathological situations: Its impact on cell proliferation. Adv Biol Regul 2014; 54:142-151. [PMID: 24091101 DOI: 10.1016/j.jbior.2013.09.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Accepted: 09/03/2013] [Indexed: 06/02/2023]
Abstract
Phosphoinositide 5-phosphatases are critical enzymes in modulating the concentrations of PI(3,4,5)P3, PI(4,5)P2 and PI(3,5)P2. The SH2 domain containing inositol 5-phosphatases SHIP1 and SHIP2 belong to this family of enzymes that dephosphorylate the 5 position of PI(3,4,5)P3 to produce PI(3,4)P2. Data obtained in zebrafish and in mice have shown that SHIP2 is critical in development and growth. Exome sequencing identifies mutations in the coding region of SHIP2 as a cause of opsismodysplasia, a severe but rare chondrodysplasia in human. SHIP2 has been reported to have both protumorigenic and tumor suppressor function in human cancer very much depending on the cell model. This could be linked to the relative importance of PI(3,4)P2 (a product of SHIP2 phosphatase activity) which is also controlled by the PI 4-phosphatase and tumor suppressor INPP4B. In the glioblastoma cell line 1321 N1, that do not express PTEN, lowering SHIP2 expression has an impact on the levels of PI(3,4,5)P3, cell morphology and cell proliferation. It positively stimulates cell proliferation by decreasing the expression of key regulatory proteins of the cell cycle such as p27. Together the data point out to a role of SHIP2 in development in normal cells and at least in cell proliferation in some cancer derived cells.
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Affiliation(s)
- William's Elong Edimo
- Interdisciplinary Research Institute (IRIBHM), Université Libre de Bruxelles, Campus Erasme, Bldg C, 808 Route de Lennik, 1070 Brussels, Belgium
| | - Stéphane Schurmans
- Laboratoire de Génétique fonctionnelle, GIGA-Research Centre, Secteur de Biochimie Métabolique, Département des Sciences Fonctionnelles (Faculté de Médecine vétérinaire), Université de Liège, 1 rue de l'Hôpital, 4000 Liège, Belgium; Walloon Excellence in Lifesciences and Biotechnology (WELBIO), Belgium
| | - Pierre P Roger
- Interdisciplinary Research Institute (IRIBHM), Université Libre de Bruxelles, Campus Erasme, Bldg C, 808 Route de Lennik, 1070 Brussels, Belgium; Walloon Excellence in Lifesciences and Biotechnology (WELBIO), Belgium
| | - Christophe Erneux
- Interdisciplinary Research Institute (IRIBHM), Université Libre de Bruxelles, Campus Erasme, Bldg C, 808 Route de Lennik, 1070 Brussels, Belgium.
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Savoy RM, Ghosh PM. The dual role of filamin A in cancer: can't live with (too much of) it, can't live without it. Endocr Relat Cancer 2013; 20:R341-56. [PMID: 24108109 PMCID: PMC4376317 DOI: 10.1530/erc-13-0364] [Citation(s) in RCA: 112] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Filamin A (FlnA) has been associated with actin as cytoskeleton regulator. Recently its role in the cell has come under scrutiny for FlnA's involvement in cancer development. FlnA was originally revealed as a cancer-promoting protein, involved in invasion and metastasis. However, recent studies have also found that under certain conditions, it prevented tumor formation or progression, confusing the precise function of FlnA in cancer development. Here, we try to decipher the role of FlnA in cancer and the implications for its dual role. We propose that differences in subcellular localization of FlnA dictate its role in cancer development. In the cytoplasm, FlnA functions in various growth signaling pathways, such as vascular endothelial growth factor, in addition to being involved in cell migration and adhesion pathways, such as R-Ras and integrin signaling. Involvement in these pathways and various others has shown a correlation between high cytoplasmic FlnA levels and invasive cancers. However, an active cleaved form of FlnA can localize to the nucleus rather than the cytoplasm and its interaction with transcription factors has been linked to a decrease in invasiveness of cancers. Therefore, overexpression of FlnA has a tumor-promoting effect, only when it is localized to the cytoplasm, whereas if FlnA undergoes proteolysis and the resulting C-terminal fragment localizes to the nucleus, it acts to suppress tumor growth and inhibit metastasis. Development of drugs to target FlnA and cause cleavage and subsequent localization to the nucleus could be a new and potent field of research in treating cancer.
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Affiliation(s)
- Rosalinda M Savoy
- Department of Urology, University of California Davis School of Medicine, University of California, 4860 Y Street, Suite 3500, Sacramento, California 95817, USA VA Northern California Health Care System, Mather, California, USA
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Xie J, Erneux C, Pirson I. How does SHIP1/2 balance PtdIns(3,4)P2 and does it signal independently of its phosphatase activity? Bioessays 2013; 35:733-43. [PMID: 23650141 DOI: 10.1002/bies.201200168] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The number of cellular events identified as being directly or indirectly modulated by phosphoinositides dramatically increased in the recent years. Part of the complexity results from the fact that the seven phosphoinositides play second messenger functions in many different areas of growth factors and insulin signaling, cytoskeletal organization, membrane dynamics, trafficking, or nuclear signaling. PtdIns(3,4)P2 is commonly reported as a product of the SH2 domain-containing inositol 5-phosphatases 1/2 (SHIP1 and SHIP2) that dephosphorylate PtdIns(3,4,5)P3 at the 5-position. Here we discuss recent interest in PtdIns(3,4)P2 signaling highlighting its involvement in key cellular mechanisms such as cell adhesion, migration, and cytoskeletal regulation. We question and discuss the involvement of SHIP2 either as a PI 5-phosphatase or as a scaffold protein in insulin signaling, cytoskeletal dynamics, and endocytosis of growth factor receptors.
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Affiliation(s)
- Jingwei Xie
- Department of Pathophysiology, China Medical University, Heping District, Shenyang Liaoning Province, China
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Elong Edimo W, Vanderwinden JM, Erneux C. SHIP2 signalling at the plasma membrane, in the nucleus and at focal contacts. Adv Biol Regul 2013; 53:28-37. [PMID: 23040614 DOI: 10.1016/j.jbior.2012.09.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Accepted: 09/04/2012] [Indexed: 06/01/2023]
Abstract
Phosphoinositide 5-phosphatases are critical enzymes in modulating the concentrations of PI(3,4,5)P(3), PI(4,5)P(2) and PI(3,5)P(2). The SH2 domain containing inositol 5-phosphatases SHIP1 and SHIP2 belong to this family of enzymes very much involved in physiopathology and development. Therefore activity and localization of the enzymes are particularly important taking into account both catalytic and non-catalytic mechanisms of the SHIP phosphatases. Several different mechanisms have been reported for SHIP2 targeting that often result from specific protein:protein interactions. In unstimulated astrocytoma cells, SHIP2 has a perinuclear and cytoplasmic localization. In serum-stimulated cells, SHIP2 can be localized at the plasma membrane and at focal contacts in polarized cells. A phosphorylated form of SHIP2 on S132 can be found in the nucleus and nuclear speckles. When present at the plasma membrane, SHIP2 may control the intracellular level of PI(3,4,5)P(3) thereby producing PI(3,4)P(2). When present in the nucleus, SHIP2 probably associates to other nuclear proteins such as lamin A/C and could potentially control nuclear PI(4,5)P(2). Finally, its presence at focal adhesions and lamellipodia could suggest a role in cell adhesion and migration. It is proposed that the complex phenotype observed in SHIP2 mutant mice in tissue development and growth could result from the addition of plasma membrane and nuclear effects consecutive to SHIP2 alteration.
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Affiliation(s)
- William's Elong Edimo
- Interdisciplinary Research Institute (IRIBHM), Université Libre de Bruxelles, Campus Erasme, Bldg. C, 808 Route de Lennik, 1070 Brussels, Belgium
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Jeon J, Leibiger I, Moede T, Walter B, Faul C, Maiguel D, Villarreal R, Guzman J, Berggren PO, Mundel P, Ricordi C, Merscher-Gomez S, Fornoni A. Dynamin-mediated Nephrin phosphorylation regulates glucose-stimulated insulin release in pancreatic beta cells. J Biol Chem 2012; 287:28932-42. [PMID: 22718751 PMCID: PMC3436561 DOI: 10.1074/jbc.m112.389452] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
We have previously demonstrated a role for Nephrin in glucose stimulated insulin release (GSIR). We now hypothesize that Nephrin phosphorylation is required for GSIR and that Dynamin influences Nephrin phosphorylation and function. MIN6-C3 Nephrin-deficient pancreatic beta cells and human islets were transfected with WT-Nephrin or with a mutant Nephrin in which the tyrosine residues responsible for SH2 domain binding were substituted with phenylalanine (3YF-Nephrin). GSIR and live images of Nephrin and vesicle trafficking were studied. Immunoprecipitation experiments and overexpression of WT-Dynamin or dominant negative Dynamin mutant (K44A-Dynamin) in WT-Nephrin, 3YF-Nephrin, or Nephrin siRNA-transfected cells were utilized to study Nephrin-Dynamin interaction. In contrast to WT-Nephrin or to single tyrosine mutants, 3YF-Nephrin did not positively affect GSIR and led to impaired cell-cell contacts and vesicle trafficking. K44A-Dynamin prevented the effect of Nephrin on GSIR in the absence of protein-protein interaction between Nephrin and Dynamin. Nephrin gene silencing abolished the positive effects of WT-Dynamin on GSIR. The effects of protamine sulfate and vanadate on Nephrin phosphorylation and GSIR were studied in MIN6 cells and human islets. WT-Nephrin phosphorylation after glucose occurred at Tyr-1176/1193 and resulted in improved GSIR. On the contrary, protamine sulfate-induced phosphorylation at Tyr-1176/1193/1217 was associated with Nephrin degradation and impaired GSIR. Vanadate, which prevented Nephrin dephosphorylation after glucose stimulation, improved GSIR in human islets and MIN6 cells. In conclusion, Dynamin-dependent Nephrin phosphorylation occurs in response to glucose and is necessary for Nephrin-mediated augmentation of GSIR. Pharmacological modulation of Nephrin phosphorylation may thus facilitate pancreatic beta cell function.
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Affiliation(s)
- Jongmin Jeon
- Diabetes Research Institute, University of Miami L. Miller School of Medicine, Miami, Florida 33136, USA
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Coló GP, Lafuente EM, Teixidó J. The MRL proteins: adapting cell adhesion, migration and growth. Eur J Cell Biol 2012; 91:861-8. [PMID: 22555291 DOI: 10.1016/j.ejcb.2012.03.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Revised: 03/08/2012] [Accepted: 03/12/2012] [Indexed: 11/19/2022] Open
Abstract
MIG-10, RIAM and Lamellipodin (Lpd) are the founding members of the MRL family of multi-adaptor molecules. These proteins have common domain structures but display distinct functions in cell migration and adhesion, signaling, and in cell growth. The binding of RIAM with active Rap1 and with talin provides these MRL molecules with important regulatory roles on integrin-mediated cell adhesion and migration. Furthermore, RIAM and Lpd can regulate actin dynamics through their binding to actin regulatory Ena/VASP proteins. Recent data generated with the Drosophila MRL ortholog called Pico and with RIAM in melanoma cells indicate that these proteins can also regulate cell growth. As MRL proteins represent a relatively new family, many questions on their structure-function relationships remain unanswered, including regulation of their expression, post-translational modifications, new interactions, involvement in signaling and their knockout mice phenotype.
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Affiliation(s)
- Georgina P Coló
- Department of Cellular and Molecular Medicine, Centro de Investigaciones Biológicas, Madrid, Spain
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