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Novel role of Vav1-Rac1 pathway in actin cytoskeleton regulation in interleukin-13-induced minimal change-like nephropathy.
Chan, Chang-Yien; Ng, Kar-Hui; Chen, Jinmiao; Lu, Jinhua; Lee, Caroline Guat-Lay; Tan, Puay-Hoon; Jordan, Stanley C; He, Henry Yang; Yap, Hui-Kim.
Afiliação
  • Chan CY; Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599, Singapore.
  • Ng KH; KTP-National University Children's Medical Institute, National University Hospital, Singapore 119260, Singapore.
  • Chen J; Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599, Singapore.
  • Lu J; KTP-National University Children's Medical Institute, National University Hospital, Singapore 119260, Singapore.
  • Lee CG; Bioinformatics, Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (A*STAR), Singapore 138648, Singapore.
  • Tan PH; Department of Microbiology, National University of Singapore, Singapore 117599, Singapore.
  • Jordan SC; Department of Biochemistry, National University of Singapore, Singapore 117599, Singapore.
  • He HY; Department of Pathology, Singapore General Hospital, Singapore 169608, Singapore.
  • Yap HK; Cedars-Sinai Medical Center, Los Angeles, CA 90048, U.S.A.
Clin Sci (Lond) ; 130(24): 2317-2327, 2016 Dec 01.
Article em En | MEDLINE | ID: mdl-27707912
ABSTRACT
Our established interleukin-13 (IL-13) overexpression rat model of minimal change-like nephropathy provided a platform to study the molecular signalling pathways in T-helper 2 (Th2) cytokine associated minimal change nephrotic syndrome (MCNS). We hypothesized that IL-13 may act directly on podocytes, causing podocyte foot process effacement and hence proteinuria in our rat model of minimal change-like nephropathy. The present study aimed firstly to delineate the glomerular 'gene signature' associated with IL-13-mediated dysregulation of podocyte-related proteins, and subsequently to investigate the role of the differentially regulated genes (DEGs) in IL-13-mediated podocyte injury. Glomerular transcriptional profile of IL-13-overexpressed rats showed characteristic features of podocyte injury with 87% of podocyte-related genes being significantly down-regulated. Gene expression of Vav1 was shown to be highly up-regulated in the glomeruli of IL-13-overexpressed rats and pathway analysis of the DEGs suggested a possible novel role of Vav1 in podocyte cytoskeleton remodelling. Immunofluorescence examination demonstrated glomerular expression of Vav1 in rats which co-localized with synaptopodin, confirming podocyte expression. However, positive staining for the phosphorylated form of Vav1 (p-Vav1) was only seen in IL-13-overexpressed rats. Moreover, in vitro IL-13 stimulation of human podocytes resulted in phosphorylation of Vav1. This was associated with Rac1 activation and actin cytoskeleton rearrangement, which was abrogated in Vav1 knockdown podocytes. In conclusion, we have demonstrated the role of Vav1-Rac1 pathway characterized by phosphorylation of Vav1, activation of Rac1 and the subsequent actin cytoskeleton rearrangement in IL-13-induced podocyte injury, possibly explaining the podocyte foot process effacement seen in our IL-13 overexpression rat model.
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Texto completo: 1 Base de dados: MEDLINE Idioma: En Ano de publicação: 2016 Tipo de documento: Article

Texto completo: 1 Base de dados: MEDLINE Idioma: En Ano de publicação: 2016 Tipo de documento: Article