CXCR3 inhibition ameliorates mitochondrial function to restrict oxidative damage via NCOA4-mediated ferritinophagy and improves the gut microbiota in mice.

Nuclear receptor coactivator 4 (NCOA4)-mediated ferritinophagy contributes to maintain intracellular iron balance by regulating ferritin degradation, which is essential for redox homeostasis. CXC-motif chemokine receptor 3 (CXCR3) is involved in the regulation of oxidative stress and autophagy. However, its role in modulating intestinal oxidative damage through ferritinophagy and the gut microbiota remains unclear. In this study, the impact of CXCR3 inhibition on intestine oxidative damage, ferritinophagy, and the gut microbiota, as well as mitochondrial quality control was investigated both in vivo and in vitro. The results show that CXCR3 inhibition by AMG487 relieves Diquat-induced intestinal damage, enhances the expression of tight junction proteins, and enhances antioxidant capacity in mice. Simultaneously, CXCR3 inhibition improves gut microbiota composition, and promotes NCOA4-mediated ferritinophagy. Mechanistically, the effects of CXCR3 inhibition on ferritinophagy are explored in IPEC-J2 cells. Co-localization and interaction between CXCR3 and NCOA4 were observed. Downregulation of NCOA4-medicated ferritinophagy leads to increase the expression of tight junction proteins, reduces iron levels, restricts ROS accumulation, and enhances GPX4 expression. Moreover, CXCR3 suppression facilitates mitochondrial biogenesis and mitochondrial fusion, increases antioxidative capacity, as well as resulting in elevation of tight junction proteins. These findings suggest that CXCR3 inhibition reverses Diquat-induced intestinal oxidative damage, enhances mitochondrial function, and improves gut microbiota composition by elevating NCOA4-medicated ferritinophagy, which implies that CXCR3 may serve as a potential therapeutic intervention targeting iron metabolism for treating intestinal diseases.