ATF3 is involved in rSjP40-mediated inhibition of HSCs activation in Schistosoma japonicum-infected mice.

Schistosomiasis is a parasitic disease characterized by liver fibrosis, a process driven by the activation of hepatic stellate cells (HSCs) and subsequent collagen production. Previous studies from our laboratory have demonstrated the ability of Schistosoma japonicum protein P40 (SjP40) to inhibit HSCs activation and exert an antifibrotic effect. In this study, we aimed to elucidate the molecular mechanism underlying the inhibitory effect of recombinant SjP40 (rSjP40) on HSCs activation. Using a cell model in which rSjP40 inhibited LX-2 cell activation, we performed RNA-seq analyses and identified ATF3 as the most significantly altered gene. Further investigation revealed that rSjP40 inhibited HSCs activation partly by suppressing ATF3 activation. Knockdown of ATF3 in mouse liver significantly alleviated S. japonicum-induced liver fibrosis. Moreover, our results indicate that ATF3 is a direct target of microRNA-494-3p, a microRNA associated with anti-liver fibrosis effects. rSjP40 was found to downregulate ATF3 expression by upregulating microRNA-494-3p in LX-2 cells. This downregulation led to the inhibition of the expression of liver fibrosis proteins α-SMA and COL1A1, ultimately alleviating liver fibrosis caused by S. japonicum.