Effects Of Dexmedetomidine On Autophagy In Intestinal Epithelial Cells Of Septic Rats

Objective:To observe the effect of dexmedetomidine(DEX)on the autophagy of intestinal epithelial cells in septic rats.Methods:1.Subjects and groups :In this study,40 male SD rats aged 8 ～ 9 weeks and weighing 230 ～ 270 g,were selected as the research objects.The selected research objects were randomly divided into 4 groups: sham operation group,model group,dexmedetomidine group(DEX group),dexmedetomidine + autophagy inhibitor3-methyladenine(3-MA)group(DEX+3-MA group).2.Establishment of rat sepsis model and grouping administration:According to the literature,the sepsis model of rats was established by cecal ligation and puncture(CLP).In sham group,the cecum was exposed by laparotomy without ligation and perforation.After model preparation,the DEX group was intraperitoneally injected with 40ug/kg DEX,and the DEX+3-MA group was intraperitoneally injected with 15mg/kg 3-MA on the basis of DEX group.3.Determination of serum inflammatory factors: Tail vein blood samples were taken 24 hours after administration.The levels of TNF-α and IL-6 in serum were determined according to the instructions in the ELISA kit.4.Pathological changes of intestinal mucosa and Chiu’s pathological score:After taking blood,the rats were killed and the tissues of small intestine were taken.After HE staining,pathological changes of intestinal mucosa were observed by light microscope,and Chiu’s pathological score was performed.5.Detection of autophagy-related markers by western blotting: After taking blood,the rats were killed and the tissues of small intestine were taken.The relative protein expression of intestinal epithelial autophagy-related markers Atg5,Beclin-1,LC3II/LC3 I was analyzed by Western blotting.Results:1.The results of serum inflammatory factor concentration showed that serum TNF-α and IL-6 concentrations were at low levels in the sham group.Compared with the sham group,the serum TNF-α and IL-6 concentrations in the model group were significantly increased(P<0.01).Compared with the model group,the serum TNF-α and IL-6 concentrations in the DEX group and the DEX+3-MA group were decreased(P<0.01).2.The pathological changes of intestinal mucosa and Chiu’s pathological score showed that in the sham group,the intestinal mucosal structure was complete,neatly and tightly arranged,with a small amount of inflammatory cell infiltration,and the Chiu’s pathological score was low.Compared with the Sham group,the integrity of the intestinal mucosa in the Model group was severely damaged,the arrangement was disordered,the infiltration of inflammatory cells was obvious,and the Chiu’s pathological score was significantly increased(P<0.01).Compared with the Model group,the DEX group and DEX+3MA group had less damage to the intestinal mucosa,less inflammatory cell infiltration,and lower Chiu’s pathological score(P<0.01).Compared with the DEX group,the DEX+3MA group had more severe mucosal damage and inflammatory cell infiltration,and the Chiu pathological score was also increased(P<0.01).3.Western blot results showed that the expression levels of intestinal epithelial autophagy-related markers Atg5,Beclin-1,and LC3II/LC3 I were low in the sham group.Compared with the sham group,the expression of intestinal epithelial autophagy-related markers Atg5,Beclin-1,LC3II/LC3 I in the model group was up-regulated(P<0.01).Compared with the model group,the expressions of intestinal epithelial autophagy-related markers Atg5,Beclin-1,and LC3II/LC3 I in the DEX group were up-regulated(P<0.01),while the intestinal epithelial autophagy-related markers Atg5,Beclin-1,and LC3II/LC3 I in the DEX+3-MA group were up-regulated(P<0.01).Compared with the DEX group,the expression of intestinal epithelial autophagy-related markers Atg5,Beclin-1,LC3II/LC3 I was down-regulated in the DEX+3-MA group(P<0.01).Conclusion:Dexmedetomidine may protect the intestinal epithelial of septic rats by up-regulating the expression of autophagy and inhibiting the level of inflammation.