艾灸调控Keap1/Nrf2通路抑制铁死亡改善克罗恩病小鼠肠道炎症OA

Objective To investigate the regulatory effects of moxibustion on intestinal ferroptosis in mice with Crohn's disease(CD)based on the Kelch-like ECH-associated protein 1(Keap1)/nuclear factor erythroid 2-related factor 2(Nrf2)pathway and its possible mechanism of action.Methods Thirty SPF-grade male C57BL/6 mice were randomly divided into normal group,model group,and moxibustion group,with 10 mice in each group.The model group and moxibustion group were given free access to 2%dextran sulfate sodium(DSS)solution for 14 consecutive days to establish CD models.After modeling,the moxibustion group received suspended moxibustion at bilateral"Tianshu"(ST25)once daily for 30 minutes each time for 14 consecutive days.No moxibustion was performed in the normal group and model group.After the intervention,general conditions,disease activity index(DAI)scores,and colon histopathological changes were observed in each group of mice.ELISA was used to determine the levels of serum inflammatory factors including tumor necrosis factor(TNF)-α,interleukin(IL)-1β,IL-6,and IL-17,as well as colonic oxidative stress and ferroptosis-related indicators such as superoxide dismutase(SOD),glutathione(GSH),glutathione peroxidase 4(GPX4),malondialdehyde(MDA),and ferrous ion(Fe2+).Reactive oxygen species(ROS)expression in colon tissue was measured by immunofluorescence staining.The protein expression levels of Keap1,Nrf2,heme oxygenase(HO)-1,and NAD(P)H:quinone oxidoreductase 1(NQO1)in colon tissue samples were determined by Western blot.Results Compared with the normal group,the mice in the model group showed a significant increase in DAI scores(P<0.01),marked inflammatory cell infiltration,and crypt structure destruction in colon tissue.The levels of serum inflammatory factors,including TNF-α,IL-1β,IL-6,and IL-17,were significantly elevated(P<0.01).SOD activity and levels of GSH and GPX4 in colon tissue were significantly decreased(P<0.01),while levels of MDA,Fe2+,and ROS were significantly increased(P<0.01).Meanwhile,Keap1 protein expression was significantly upregulated(P<0.01),whereas protein expression of Nrf2,HO-1,and NQO1 was significantly downregulated(P<0.01).Compared with the model group,the mice in the moxibustion group showed a significant reduction in DAI score(P<0.01)and marked alleviation of pathological damage in colon tissue.The levels of serum inflammatory factors,including TNF-α,IL-1β,IL-6,and IL-17,were significantly reduced(P<0.01 or P<0.05).SOD activity and levels of GSH and GPX4 in colon tissue were significantly increased(P<0.01 or P<0.05),while levels of MDA,Fe2+,and ROS were significantly decreased,and the differences were statistically significant(P<0.05 or P<0.01).Keap1 protein expression level was significantly downregulated(P<0.01),while protein expression of Nrf2,HO-1,and NQO1 was significantly upregulated(P<0.01).Conclusion Moxibustion at"Tianshu"(ST25)can ameliorate intestinal inflammatory injury in mice with CD,and its mechanism of action is closely related to regulating the Keap1/Nrf2 pathway,enhancing antioxidant capacity,and inhibiting intestinal ferroptosis.