?-arrestin-1 drives endothelin-1-mediated podocyte activation and sustains renal injury.

ABSTRACT: Activation of endothelin-A receptor (ET(A)R) by endothelin-1 (ET-1) drives epithelial-to-mesenchymal transition in ovarian tumor cells through ?-arrestin signaling. Here, we investigated whether this pathogenetic pathway could affect podocyte phenotype in proliferative glomerular disorders. In cultured mouse podocytes, ET-1 caused loss of the podocyte differentiation marker synaptopodin and acquisition of the mesenchymal marker ?-smooth muscle actin. ET-1 promoted podocyte migration via ET(A)R activation and increased ?-arrestin-1 expression. Activated ET(A)R recruited ?-arrestin-1 to form a trimeric complex with Src leading to epithelial growth factor receptor (EGFR) transactivation and ?-catenin phosphorylation, which promoted gene transcription of Snail. Increased Snail expression fostered ET-1-induced migration as confirmed by Snail knockdown experiments. Silencing of ?-arrestin-1 prevented podocyte phenotypic changes and motility and inhibited ET(A)R-driven signaling. In vitro findings were confirmed in doxorubicin (Adriamycin)-induced nephropathy. Mice receiving Adriamycin developed renal injury with loss of podocytes and hyperplastic lesion formation; ?-arrestin-1 expression increased in visceral podocytes and in podocytes entrapped in pseudo-crescents. Administration of the selective ET(A)R antagonist sitaxsentan prevented podocyte loss, formation of the hyperplastic lesions, and normalized expression of glomerular ?-arrestin-1 and Snail. Increased ?-arrestin-1 levels in podocytes retrieved from crescents of patients with proliferative glomerulopathies confirmed the translational relevance of these findings and suggest the therapeutic potential of ET(A)R antagonism for a group of diseases still needing a specific treatment.

SUBMITTER: Buelli S 

PROVIDER: S-EPMC3935587 | biostudies-literature | 2014 Mar

REPOSITORIES: biostudies-literature