The Study On The Mechanism Of Hypoxia Inducible Factor-1 ? In Intestinal Epithelial Injury In Sepsis

Objective:To study the role and mechanism of hypoxia inducible factor-1?in intestinal epithelial injury in sepsis.Methods:In vivo:The rat model of sepsis was established.24 S-D rats were randomly divided into 4 groups(6 rats/group):Sham group;Sepsis group;DMOG(HIF-1?activator)group;and BAY87-2243 group(HIF-1?inhibitor)group.24 hours after cecal ligation and perforation,IL-1?,IL-6,TNF-?,diamine oxidase,intestinal fatty acid binding protein and D-lactic acid in serum were detected by Elisa;MDA,SOD and CAT were detected by biochemistry;Fluorescence dextran was detected by fluorescence method;H&E staining and Chiu's score were to evaluate intestinal tissue injury;Western blot was to detect the expression of HIF-1?,ZO-1,Occludin and Claudin-1 in intestinal tissue.In vitro:The Caco-2 cells were divided into 8 groups:Control group,LPS group,DMOG+LPS group,BAY-87-2243+LPS group,Rapamycin(mTOR inhibitor)+LPS group,MHY1485(mTOR activator)+LPS group,DMOG+Rapamycin+LPS group,BAY87-2243+MHY1485+LPS group.The model of Caco-2 cells monolayer barrier was established.The transmembrane resistance was measured by ERS-2 resistance meter,the permeation of fluorescein-labeled dextran was measured by fluorescence method,and the expression of HIF-1?,ZO-1,Occludin,Claudin-1,p-mTOR and p-P70S6K was detected by Western blot.Results:In vivo:Compared with Sepsis group,DMOG significantly decreased the contents of TNF-?,IL-1?,IL-6,DAO,FABP2,D-LA,FD-4 permeability and MDA,increased activity of CAT and SOD,alleviated intestinal injury,decreased pathological score,and increased the expression of HIF-1?and TJs(ZO-1,Occludin,Claudin-1)in intestinal tissue of septic rats(P<0.05).BAY87-2243 significantly increased the expression of TNF-?,IL-1?and IL-6,DAO,FABP2,D-LA,FD-4 permeability and MDA,decreased the activity of CAT and SOD,aggravated intestinal injury,increased pathological score and decreased the expression of HIF-1?and TJs in intestinal tissue of septic rats(P<0.05).In vitro:Compared with LPS group,DMOG significantly increased the TEER value of Caco-2 monolayer barrier,decreased the permeability of FD-4,and increased the expression level of HIF-1?and TJs in Caco-2 cells(P<0.05).However,BAY87-2243 significantly decreased the TEER value,increased the permeability of FD-4 and decreased the expression of HIF-1?and TJs in Caco-2 cells(P<0.05).Rapamycin decreased the TEER value,increased the permeability of FD-4,and decreased the expression of p-mTOR,p-P70S6K,HIF-1?and TJs in Caco-2 cells(P<0.05).MHY1485 insignificantly increased the TEER value,decreased the permeability of FD-4,and increase the expression of p-mTOR,p-P70S6K,HIF-1?and TJs in Caco-2 cells(P<0.05).The effect caused by Rapamycin was rescued by DMOG(P<0.05).The effect caused by MHY1485 was rescued by BAY-87-2243(P<0.05).Conclusion:HIF-1?reduced the levels of inflammation and oxidative stress in septic rats,alleviated intestinal epithelial injury,and was regulated by mTOR/P70S6K signal pathway.