The motor protein Myo1c regulates transforming growth factor-?-signaling and fibrosis in podocytes.

ABSTRACT: Transforming growth factor-? (TGF-?) is known to play a critical role in the pathogenesis of many progressive podocyte diseases. However, the molecular mechanisms regulating TGF-? signaling in podocytes remain unclear. Using a podocyte-specific myosin (Myo)1c knockout, we demonstrate whether Myo1c is critical for TGF-?-signaling in podocyte disease pathogenesis. Specifically, podocyte-specific Myo1c knockout mice were resistant to fibrotic injury induced by Adriamycin or nephrotoxic serum. Further, loss of Myo1c also protected from injury in the TGF-?-dependent unilateral ureteral obstruction mouse model of renal interstitial fibrosis. Mechanistic analyses showed that loss of Myo1c significantly blunted TGF-? signaling through downregulation of canonical and non-canonical TGF-? pathways. Interestingly, nuclear rather than the cytoplasmic Myo1c was found to play a central role in controlling TGF-? signaling through transcriptional regulation. Differential expression analysis of nuclear Myo1c-associated gene promoters showed that nuclear Myo1c targeted the TGF-? responsive gene growth differentiation factor (GDF)-15 and directly bound to the GDF-15 promoter. Importantly, GDF15 was found to be involved in podocyte pathogenesis, where GDF15 was upregulated in glomeruli of patients with focal segmental glomerulosclerosis. Thus, Myo1c-mediated regulation of TGF-?-responsive genes is central to the pathogenesis of podocyte injury. Hence, inhibiting this process may have clinical application in treating podocytopathies.

SUBMITTER: Arif E 

PROVIDER: S-EPMC6589397 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature