Autophagic inhibitor ROC-325 ameliorates glomerulosclerosis and podocyte injury via inhibiting autophagic flux in experimental FSGS mice

Abstract

Background: Autophagy plays an important role in the pathogenesis of focal segmental glomerulosclerosis (FSGS). Podocyte-specific Yes-associated protein (YAP) deletion mice, referred to as YAP-KO mice, is considered a new animal model to study the underlying mechanism of FSGS. ROC-325 is a novel small-molecule lysosomal autophagy inhibitor that is more effective than chloroquine (CQ) and hydroxychloroquine (HCQ) in suppressing autophagy. In this study, we sought to determine the therapeutic benefit and mechanism of action of ROC-325 in YAP-KO mice, an experimental FSGS model.

Methods and results: YAP-KO mice were treated with ROC-325 (50 mg/kg, p.o.) daily for one month. Our results revealed that albuminuria, mesangial matrix expension, and focal segmental glomerulosclerosis in YAP-KO mice were significantly attenuated by ROC-325 administration. Transmission electron microscopy and immunofluorescence staining showed that ROC-325 treatment significantly inhibited YAP-KO-induced autophagy activation by decreasing autophagosome-lysosome fusion and increasing LC3A/B and p62/SQSTM. Meanwhile, Immunofluorescence staining revealed that preapplication of ROC-325 in podocyte with YAP-targeted siRNA and mRFP-GFP-LC3 adenovirus markedly suppressed autophagic flux in vitro, suggesting that autophagy intervention may serve as a target for FSGS.

Conclusions: These results showed that the role of autophagic activity in FSGS mice model and ROC-325 could be a novel and promising agent for the treatment of FSGS.

Keywords: Autophagy; Focal segmental glomerulosclerosis; Podocyte; ROC-325; Yes-associated protein (YAP).