LAUSR

&NA; NLRC5, the largest member of the Nucleotide‐binding domain and leucine‐rich repeat (NLR) protein family, is recently proven to be a critical modulator in fibrogenesis. However, the role of NLRC5 in renal fibrosis remains unknown. In the present study, we investigated the effects of NLRC5 on transforming growth factor &bgr;1 (TGF‐&bgr;1)‐stimulated rat renal fibroblasts in vitro. Our results showed that the expression of NLRC5 was also obviously upregulated in renal fibrosis tissues and TGF‐&bgr;1‐treated NRK‐49F cells. Knockdown of NLRC5 inhibited the proliferation of NRK‐49F cells induced by TGF‐&bgr;1, as well as suppressed the accumulation of extracellular matrix (ECM) in NRK‐49F cells induced by TGF‐&bgr;1. Furthermore, knockdown of NLRC5 inhibited the expression of phosphorylated Smad3 in TGF‐&bgr;1‐treated NRK‐49F cells. In conclusion, our results show that knockdown of NLRC5 inhibits renal fibroblast activation via modulating TGF‐&bgr;1/Smad signaling pathway. Therefore, NLRC5 may act as a key mediator in renal fibroblast activation and fibrogenesis.