Role Of HDAC6 Regulates Histone H3 Acetylation And Autophagy In Sodium Butyrate Attenuating Intestinal Ischemia-Reperfusion Injury In Mice

Objective:To evaluate the involvement of histone deacetylase 6(HDAC6)and its potential mechanisms in mitigating intestinal ischemia-reperfusion(I/R)injury via sodium butyrate administration in mice.Methods: Thirty-six SPF healthy adult male C57BL/6 mice,aged 8-10 weeks,weighing 22-25 g,were divided into 6 groups(n=6 each)by the random number table method : sham operation group(S group),sham operation +sodium butyrate group(SB group),sham operation+HDACs activator(ITSA-1)group(ITSA group),intestinal ischemia-reperfusion group(I/R group),intestinal ischemia-reperfusion + sodium butyrate group(I/R+SB group),intestinal is chemia-reperfusion +ITSA-1+ sodium butyrate group(I/R+ITSA+SB group).The mouse model of intestinal ischemia-reperfusion injury was established by clamping the superior mesenteric artery(SMA)for 45 min and reperfusion for120 min.In ITSA group and I/R+ITSA+SB group,the HDACs activator ISSA-1 0.5 mg/kg was injected intraperitoneally on day 6,3 and 1,respectively,1week before ischemia.The SB,I/R+SB and I/R+ITSA+SB groups were given sodium butyrate 500 mg/kg daily by gavage 1 week before ischemia,and the equal volume of nomal saline was given in S group and I/R group.At 120min of reperfusion,the mice were sacrificed after taking blood from the heart.The small intestine tissue samples were taken about 5 cm from the ileocecal valve,and the levels of diamine oxidase(DAO)in serum and small intestine tissue were detected by enzyme-linked immunosorbent assay(ELISA).Histopath ological changes of small intestine were observed under light microscope and intestinal damage was assessed according to Chiu’s score.The expression levels of HDAC6,microtubule-associated protein light chain 3II(LC3II)and P62 in small intestinaltissues were determined by Western blot.The contents of histone H3 and acetylated histone H3(Ac-H3)in small intestinal tissues were dete rmined by ELISA.Results: Compared with S group,there were no significant differences in Chiu’s score,serum and small intestinal tissue DAO in SB group and ITSA group( > 0.05),the chiu’s score,levels of DAO in serum and small intestina ltissues were increased,the expression of HDAC6 and LC3 II in small intestinal tissue was up-regulated,P62 was down-regulated,histone H3 content was increased,and Ac-H3 content was decreased in I/R group( < 0.05).Compared with I/R group,the Chiu’s score,levels of DAO in serum and small intestine tissues were significantly decreased,the expressions of HDAC6 and LC3 II were down-regulated,P62 expression was up-regulated,histone H3 content was decreased,and Ac-H3 content was increased in I/R+SB group( < 0.05).Compared with I/R+SB group,the Chiu’s score and levels of DAO in serum a nd small intestinal tissue were significantly increased,the expression of HDA C6 and LC3 II were up-regulated,P62 expression was down-regulated,histone H3 content was increased,and Ac-H3 content was decreased in I/R+ITSA+SB group( < 0.05).Conclusion: Sodium butyrate can alleviate intestinal I/R injury by HDAC6 in mice,and the mechanism may be related to promoting of histone H3 acetylation and inhibiting autophagy.