Adipose mesenchymal stem cell-derived extracellular vesicles alleviate renal fibrosis by reducing epithelial-mesenchymal transition via the FOXS1/Wnt/β-catenin signaling pathway

Adipose mesenchymal stem cells (ADSCs) exert beneficial effects on kidney disease through a paracrine mechanism. However, the specific molecular mechanisms by which ADSCs treat renal fibrosis are not yet fully understood. Therefore, it is crucial to clarify the therapeutic effects of ADSC-derived extracellular vesicles (ADSC-EVs) on the progression of renal fibrosis and their underlying mechanisms. We investigated the therapeutic effects of ADSC-EVs on renal fibrosis both in vivo and in vitro. Key genes and signaling pathways were identified with RNA sequencing analysis of HK-2 cells. The role and underlying mechanism of the FOXS1/Wnt/β-catenin pathway in mediating antifibrotic effects were also verified. In vivo, We found that ADSC-EV treatment significantly improves renal fibrosis in unilateral ureteral obstruction (UUO)-induced renal fibrosis mice models. And in vitro, our data suggested that ADSC-EVs can reduce epithelial-mesenchymal transition (EMT) to inhibit fibrosis in transforming growth factor-β1 (TGF-β1)-treated HK-2 cells. The RNA sequencing results showed that FOXS1 was the primary gene involved in ADSC-EV treatment of renal fibrosis. RT-qPCR suggested that ADSC-EV treatment reversed elevated FOXS1 level both in TGF-β1-treated HK-2 cells and UUO-induced renal fibrosis mice models. Moreover, Western blot analysis confirmed that ADSC-EVs alleviate renal fibrosis and EMT by inhibiting the expression of FOXS1 in HK-2 cells treated with TGF-β1. Furthermore, overexpression of FOXS1 in HK-2 cells could promote the occurrence of fibrosis and knockdown of FOXS1 could reduce the occurrence of fibrosis. Finally, ADSC-EVs may exert these effects via FOXS1-mediated activation of the Wnt/β-catenin pathway. Taken together, we have confirmed that ADSC-EVs alleviate renal fibrosis by reducing EMT via the FOXS1/Wnt/β-catenin signaling pathway.