Role Of Histone Deacetylase 6 In Butyrate Attenuating Intestinal Ischemia-Reperfusion Injury In Mice:Relationship With Oxidative Stress And Cell Apoptosis

Objective: To explore the role of histone deacetylase 6 in butyrate attenuating intestinal ischemia-reperfusion injury in mice and the relationship with oxidative stress and apoptosis.Methods: Thirty-six SPF healthy male C57 BL mice,aged 8-10 weeks,weighing22-25 g,were divided into 6 groups(n=6 each)according to the random number table method: sham operation group(S group),sham operation+butyrate group(SB group),sham operation+ITSA-1 group(SI group),intestinal I/R group(IR group),intestinal I/R+butyrate group(IB group)and intestinal I/R+ITSA-1+butyrate group(IIB group).In IR,IB and IIB groups,the superior mesenteric artery was clamped for 45 min,followed by reperfusion for 2 h to prepare the model of intestinal I/R injury,while the superior mesenteric artery was only isolated without ligation in S,SB and SI groups.One week before preparation of the model,butyrate 500 mg/kg was intragastrically administered once a day in SB,IB and IIB groups,the HDAC activator ITSA-1 0.5mg/kg was intraperitoneally injected three times a week in SI and IIB groups,and the equal volume of normal saline was given instead in the other groups.The mice were sacrificed at 2 h of reperfusion and small intestinal tissues were obtained for microscopic examination of the pathological changes which were assessed using Chiu’s score and for determination of the content of MDA,SOD,Bax and Bcl-2(by ELISA)and expression of Cleaved Caspase-3,HDAC6 and AC-H3(by Western blot).Results: There was no significant difference in Chiu’s score among S group,SB group and SI group(P>0.05).Compared with S group,Chiu’s score was increased,the content of Bax was increased and the expression of Cleaved Caspase-3 and HDAC6 expression was up-regulated in IR,IB,and IIB groups,the content of MDA was increased,the content of SOD and Bcl-2 were decreased,the expression of Ac-H3 was down-regulated in IR and IIB groups(P < 0.05).Compared with IR group,Chiu’s score and the content of Bax were decreased in IB and IIB groups,the content of MDA was decreased,the expression of Cleaved Caspase-3 and HDAC6 were down-regulated,the content of SOD and Bcl-2 were increased and the expression of Ac-H3 was up-regulated in IB group(P < 0.05);Compared with IB group,Chiu’s score,the content of MDA and Bax were increased,the expression of Cleaved Caspase-3 and HDAC6 were up-regulated,the content of SOD and Bcl-2 were decreased,the expression of Ac-H3 was down-regulated in IIB group(P<0.05).Conclusion: 1.Butyrate can attenuate intestinal I/R injury in mice;2.The reduction of intestinal I/R injury in mice by butyrate is related to inhibition of oxidative stress and apoptosis;3.HDAC6 is involved in the process of butyrate attenuating intestinal ischemia-reperfusion injury in mice,which is related to regulating the expression of acetylated histone H3,inhibiting oxidative stress and apoptosis.