Chac1 silencing mitigates hemorrhagic shock-induced intestinal injury by inhibiting oxidative stress and ferroptosis

Abstract

Hemorrhagic shock (HS) is a common and significant cause of mortality and morbidity, often resulting in structural damage and dysfunction of the intestines. ChaC glutathione-specific gamma-glutamylcyclotransferase 1 (Chac1) has been reported to be involved in the regulation of oxidative stress and ferroptosis in mammals. Herein, we investigate the effects of Chac1 on HS-induced intestinal injury induced by HS both in vitro and in vivo. Sprague-Dawley rat model with HS was established, and our investigations showed upregulation of the mRNA and protein levels of Chac1 in the model’s ileum tissues. Histopathological analysis revealed that knockdown of Chac1 attenuated the intestinal injury induced by HS. Depletion of Chac1 also reduced the increase in intestinal fatty acid binding protein (I-FABP) concentration. Immunofluorescence staining indicated that silencing Chac1 significantly suppressed the downregulation of occludin and zonula occludens-1 (ZO-1). HS-induced changes in lipid peroxidation (LPO), malondialdehyde (MDA), and glutathione (GSH) levels were reversed in the absence of Chac1, suggesting that downregulation of Chac1 alleviated HS-induced oxidative stress. Additionally, HS led to a decrease in glutathione peroxidase 4 (Gpx4) and ferritin heavy chain 1 (Fth1) expression, along with an increase in ferrous ion (Fe2+) concentration. Knockdown of Chac1 significantly inhibited ferroptosis by increasing Gpx4 and Fth1 expression while reducing the Fe2+ concentration. In vitro experiments using the rat small intestine crypt epithelial cells (IEC-6) demonstrated that depletion of Chac1 suppressed oxidative stress and ferroptosis induced by hypoxia/reoxygenation (H/R). In conclusion, our study provides evidence that downregulation of Chac1 mitigates HS-induced intestinal injury by inhibiting oxidative stress and ferroptosis.