Ferroptosis mediated DSS-induced ulcerative colitis associated with Nrf2/HO-1 signaling pathway.

Ulcerative colitis (UC) is an inflammatory disease characterized by an uncontrolled inflammatory response. Previous study showed that the immunological impairment elicted the alteration of inflammatory mediators, and ferroptosis was implicated with the lethal accumulation of reactive oxygen species (ROS). Therefore, this study aimed to investigate the role of ferroptosis in dextran sulfate sodium (DSS)-induced UC. The animal model was established and the molecular markers of ferroptosis were detected by using western blot. The results suggested that the expression of COX2 and ACSL4 was increased dramatically, while the level of GPX4 and FTH1 was deceased in 3% DSS group compared with Control group (P < 0.05). Meanwhile, the body weight and colon length were significantly increased, and the inflammation indexes and MDA levels were reduced in 3% DSS+ ferrostatin-1 group, 3% DSS+ liproxstatin-1 group and 3% DSS+ deferprone group compared to 3% DSS group (P < 0.05). Additionally, the mRNA and protein level of COX2 and ACSL4 were obviously upregulated, but the GPX4 and FTH1 expression were downregulated in 3% DSS group (P < 0.05); however, the expression level of COX2, ACSL4, GPX4 and FTH1 was revered after ferrostatin-1, liproxstatin-1 (Lip-1) or deferprone (DFP) administration. The immunohistochemical assay showed that the staining intensity of COX2 was decreased and the staining intensity of GPX4 was increased in 3% DSS+ Ferr-1 group compared with 3% DSS group (P < 0.05). Moreover, the nuclear factor erythoid 2-related 2 (Nrf2) and HO-1 expression were lower in 3% DSS+ Ferr-1 group than 3% DSS group (P < 0.05). These data revealed that suppressing ferroptosis could effectively ameliorate DSS-induced UC involved in blocking Nrf2/HO-1 signaling pathway.