SIRT4-Mediated Deacetylation of PRDX3 Attenuates Liver Ischemia Reperfusion Injury by Suppressing Ferroptosis.

Liver ischemia-reperfusion injury (LIRI) is an important cause of the clinical prognosis of liver transplantation. Despite Sirtuin 4 (SIRT4) is involved in various post-translational modifications, its role in LIRI is unclear. This research aimed to investigate the influence of SIRT4 on the pathogenesis of LIRI. To this end, SIRT4 knockout (KO) and liver-specific overexpression mice, as well as alpha mouse liver 12 (AML12) cells, were employed. We showed that SIRT4 expression was downregulated in mice with LIRI or AML12 cells exposed to hypoxia-reoxygenation (H/R) injury, as well as in the liver tissue of liver transplant patients. SIRT4 KO exacerbated liver injury and ferroptosis; conversely, liver-specific SIRT4 overexpression in mice produced the opposite results. Furthermore, the ferroptosis inhibitor ferrostatin-1 mitigated the exacerbation of liver injury and ferroptosis caused by SIRT4 KO. Mechanistically, SIRT4 interacted with peroxiredoxins 3 (PRDX3) and deacetylated it at lysine 92, leading to the inhibition of ferroptosis. Furthermore, the protective effect of SIRT4 on LIRI was dependent on PRDX3 deacetylation at lysine 92. Additionally, liver-targeted lipid nanoparticles (LNPs)-sirt4 mRNA alleviated LIRI and ferroptosis in mice. Taken together, our findings highlight the SIRT4-PRDX3 axis as a key regulator and potential therapeutic target for LIRI.