Sirtuin five knockdown induced the ferroptosis of hepatic stellate cells in hepatic fibrosis progression through de-succinylation modification of GPX4

Abstract

Hepatic fibrosis results from persistent pathological damage and repair following various chronic liver injuries. In this study, we explored the specific mechanism of sirtuin 5 (SIRT5) in the development of hepatic fibrosis. Transforming growth factor-beta 1 (TGF-β1)-treated LX-2 cells and CCl4-treated mice were used to establish hepatic fibrosis models in vitro and in vivo. Cell viability was assessed using the CCK-8 assay, and ferroptosis-related indicators were measured with commercial kits. Protein expression and succinylation levels were analyzed by Western blot. Liver tissue structure in fibrotic mice was evaluated using hematoxylin and eosin (H&E), Masson, and Sirius Red staining. SIRT5 expression and global succinylation levels were elevated in TGF-β1-treated LX-2 cells. Knockdown of SIRT5 reduced cell viability and glutathione (GSH) levels while increasing malondialdehyde (MDA), iron, and reactive oxygen species (ROS) levels in these cells. Furthermore, SIRT5 knockdown enhanced the succinylation of glutathione peroxidase 4 (GPX4) and decreased GPX4 protein stability and expression. In vivo experiments showed that SIRT5 knockdown ameliorated liver structure in fibrotic mice by targeting GPX4 expression. Our study demonstrates that SIRT5 knockdown induces ferroptosis in TGF-β1-treated LX-2 cells by decreasing GPX4 protein levels via desuccinylation.