Thymosin beta 4 alleviates non-alcoholic fatty liver by inhibiting ferroptosis via up-regulation of GPX4

Thymosin beta 4 (T84) can improve the liver fibrosis and reduce inflammation, while the role of T84 in nonalcoholic fatty liver disease (NAFLD) whether mediated by ferroptosis remains unclear. A rat model of NAFLD was established on a high-fat diet (HFD), and rats were assigned ferroptosis inducer erastin and inhibitor Ferrostatin 1 (Fer-1). Subsequently, histopathology of the liver and the expression of ferroptosis-related genes in rat liver were detected. The steatosis of LO2 cells was induced by palmitic acid (PA) to reproduce the results of the rat experiment. The small interfering RNA (siRNA) was used to interfere with GPX4 expression to explore the influence on T84 function. T84 improved the inflammation, biochemical and lipid metabolism indexes, increased the antioxidant level, and inhibited abnormal accumulation of intracellular reactive oxygen species in HFDinduced NAFLD rats. Also, T84 improved PA-induced LO2 damage and inhibited apoptosis of PA-induced LO2 cells. Both in vivo and in vitro, T84 regulated expression of genes associated with ferroptosis, and Fer-1 treatment exaggerated the above effects of T84, while erastin attenuated the protective effect of T84. Moreover, siRNA GPX4 attenuated the protective effect of T84 on the rat liver and on the mitochondrial membrane integrity of LO2 cells. Interfered expression of GPX4 with siRNA also regulated the expression of Bcl-2, Bax, Caspase-3 and SOD1, which attenuated therapeutic effect of T84 on rat liver and LO2 cells. This study revealed that T84 protects hepatocytes by inhibiting the GPX4-mediated ferroptosis pathway, which provides a new strategy and target for the treatment of NAFLD.

Automated summary

The study reveals that T84 protects hepatocytes by inhibiting the GPX4-mediated ferroptosis pathway in NAFLD rats and LO2 cells. It also confirms the exacerbating effect of Fer-1 on the function of T84 and the attenuating effect of erastin on the protective effect of T84. Moreover, interference with GPX4 expression can weaken the protective effect of T84 on liver and LO2 cells.