Hirsutella sinensis inhibits NLRP3 inflammasome activation to block aristolochic acid-induced renal tubular epithelial cell transdifferentiation.

In recent years, kidney damage caused by ingestion of Chinese medicinal herbs containing Aristolochic acid (AA) has attracted extensive attention. However, whether the nephrotoxicity of AA is related to NLRP3 inflammasome has not been reported. Hirsutella sinensis (HS) has a certain therapeutic effect on aristolochic acid nephropathy (AAN) and is related to NLRP3 inflammasome. Therefore, this study explores whether HS plays a role in renal injury induced by AA through NLRP3 inflammasome pathway. AA-stimulated renal tubular epithelial cells showed that AA could promote the expression of NLRP3, ASC, and α-SMA, increase the secretion and expression of caspase-1, IL-1β, and IL-18, and inhibit the expression of E-cadherin in a dose- and time-dependent manner. When NLRP3 was down-regulated, the expression of α-SMA and E-cadherin did not change significantly, but significantly blocked the regulation of α-SMA and E-cadherin expression by AA. When AA and HS were added to renal tubular epithelial cells at the same time, the effects of AA on the expression of NLRP3, ASC, caspase-1, IL-1β, IL-18, and α-SMA gradually decreased to the level of control group with the increase of HS dosage. At the same time, HS can reduce the transdifferentiation of renal tubular epithelial cells by inhibiting the activation of NLRP3 inflammasome. These findings will provide important pharmacological references for the treatment of AAN and the clinical application of HS.