The m6A reader YTHDF3-mediated PRDX3 translation alleviates liver fibrosis

Peroxiredoxin 3 (PRDX3) acts as a master regulator of mitochondrial oxidative stress and exerts hepatoprotective effects, but the role of PRDX3 in liver fibrosis is not well understood. N⁶-methyladenosine (m6A) is considered the most prevalent posttranscriptional modification of mRNA. This study aimed to elucidate the effect of PRDX3 on liver fibrosis and the potential mechanism through which the m6A modification regulates PRDX3. PRDX3 expression was found to be negatively correlated with liver fibrosis in both animal models and clinical specimens from patients. We performed adeno-associated virus 9 (AAV9)-PRDX3 knockdown and AAV9-PRDX3 HSC-specific overexpression in mice to clarify the role of PRDX3 in liver fibrosis. PRDX3 silencing exacerbated hepatic fibrogenesis and hepatic stellate cell (HSC) activation, whereas HSC-specific PRDX3 overexpression attenuated liver fibrosis. Mechanistically, PRDX3 suppressed HSC activation at least partially via the mitochondrial reactive oxygen species (ROS)/TGF-β1/Smad2/3 pathway. Furthermore, PRDX3 mRNA was modified by m6A and interacted with the m6A readers YTH domain family proteins 1-3 (YTHDF1-3), as evidenced by RNA pull-down/mass spectrometry. More importantly, PRDX3 expression was suppressed when YTHDF3, but not YTHDF1/2, was knocked down. Moreover, PRDX3 translation was directly regulated by YTHDF3 in an m6A-dependent manner and thereby affected its function in liver fibrosis. Collectively, the results indicate that PRDX3 is a crucial regulator of liver fibrosis and that targeting the YTHDF3/PRDX3 axis in HSCs may be a promising therapeutic approach for liver fibrosis.