The Role And Mechanism Of MiR-210 Negative Feedback Regulation Of HIF-1α Mediated Autophagy Experimental Colitis In Mice

Objective: The correlation between HIF-1α(Hypoxia-inducible factor-1α,HIF-1α)and miR-210 and autophagy-related gene expression was investigated,and the inflammation and autophagy of mouse ulcerative colitis induced by dextran sodium sulfate(DSS)were observed by inhibiting the expression of HIF-1α and miR-210,respectively.210 in inflammatory bowel disease and provides a theoretical basis for finding new targets for the treatment of inflammatory bowel disease.Methods: Fifty-six 8-week-old male Balb/c mice were randomly divided into 7 groups of 8 mice each after a one-week acclimatization feeding.7 groups of mice were divided into normal control(Control)group,DSS group,DSS+HIF-1α inhibitor(DH)group,DSS+miR-210 inhibitor(DM)group,DSS+miR-210 The mice in the DSS group were given 3% DSS solution for 7 days,and the feeding bottles were washed and replaced with new 3% DSS drinking water daily.The clinical condition of each mouse was observed and recorded daily from the date of modeling,including changes in body mass,stool properties,blood in the stool,feeding,and activity of the mice.HIF-1α inhibitor(PX-478)was administered by gavage to mice in the HIF-1α inhibitor group at a concentration of 20 mg/kg dissolved in 10% DMSO for 3 days.miR-210 inhibitor was administered intraperitoneally to mice in the miR-210 inhibitor(miR-210antagomir)group at a concentration of(10 nmol in 150 μl)dissolved in saline for 3 days.miR-210 inhibitor was administered to mice in the miR-210 control(miR-210 antagomir NC)group at a concentration of(10 nmol in 150 μl)dissolved in saline for 3 days.On day11,the mice were executed by cervical dislocation,and the serum and colonic tissues were preserved in a refrigerator at-80°C.The results of DAI and colon histopathology were used to evaluate the general condition of the mice and the degree of inflammation in the colon tissues.α,miR-210,ATG7 and Beclin-1 in mouse colon tissues by RT-PCR,and HIF-1α,Beclin1 and ATG7 in mouse colon tissues by Western blot.Results: During the modeling period of acute experimental colitis in mice,except for the normal control group,all other groups of mice showed decreased body weight and vitality,accompanied by occult blood in the stool or bloody stools,and the colon tissues showed shortened colon,congested and swollen intestinal lumen,petechiae and ulcer formation,suggesting that the modeling of experimental colitis in mice was successful.The difference was not statistically significant.The mice in the DSS+HIF-1α inhibitor group lost more weight than the mice in the DSS group and showed higher inflammation.The mice in the DSS+miR-210 inhibitor group showed better weight loss and less inflammation than the mice in the DSS group,and the expression levels of the inflammatory factors IL-6 and TNF-α were lower than those in the DSS group,while the expression levels of the inflammatory factor IL-10 and the autophagy-related genes ATG7 and Beclin 1 were higher than those in the DSS group(P<0.05).The mice in the DSS + HIF-1α inhibitor + miR-210 inhibitor group showed severe weight loss and increased inflammation compared with the DSS group.After ELISA,the pro-inflammatory factor IL-6 and TNF α were elevated compared with the DSS group,and the anti-inflammatory factor IL-10,autophagy-related gene Beclin 1 and ATG7 were decreased compared with the DSS group,but not as severe as the inflammation in the mice in the DSS + HIF-1α inhibitor group.There was no significant difference between the DSS+miR-210 inhibitor control group and the DSS group mice,which was not statistically significant(P>0.05).there was no significant difference between the DSS+HIF-1α inhibitor+miR-210 inhibitor control group and the DSS+HIF-1α inhibitor group mice(P >0.05).Conclusion: The inhibitor of HIF-1α(PX-478)could induce down-regulation of the expression of autophagic pathway ATG7,Beclin 1 gene and protein in mouse colon tissue,aggravate the inflammation of intestinal mucosal tissue and increase the expression of pro-inflammatory cytokines IL-6 and TNF-α levels in serum.It is suggested that HIF-1α may be positively correlated with the level of autophagy in mouse intestinal epithelial cells;HIF-1α may reduce DSS-induced acute ulcerative colitis in mice by regulating autophagy in intestinal epithelial cells.HIF-1α expression was upregulated in mouse colon tissues after administration of miR-210 antagomir(miR-210inhibitor).It is suggested that miR-210 inhibitor(miR-210 antagomir)can upregulate HIF-1α expression through negative feedback.In turn,it upregulated the expression of ATG7 and Beclin 1 gene in the autophagy pathway and suppressed the level of inflammation in the mouse colon.