Role of endoplasmic reticulum stress-mediated apoptosis in proanthocyanidins-induced attenuation of intestinal ischemia-reperfusion injury in mice / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the role of endoplasmic reticulum stress-mediated apoptosis in proanthocyanidins-induced attenuation of intestinal ischemia-reperfusion (I/R) injury in mice.Methods:Thirty SPF healthy adult male C57BL/6 mice, aged 8-10 weeks, weighing 20-25 g, were divided into 5 groups ( n=6 each) by a random number table method: sham operation group (S group), sham operation + proanthocyanidins group (S+ PC group), intestinal I/R group (I/R group), intestinal I/R + proanthocyanidins group (I/R+ PC group) and intestinal I/R + proanthocyanidins + tunicamycin group (I/R+ PC+ TM group). The superior mesenteric artery was clamped for 60 min and reperfused for 120 min to establish a mouse intestinal I/R injury model.Proanthocyanidin 100 mg/kg was given by intragastric gavage every day 1 week before ischemia in S+ PC group, I/R+ PC group and I/R+ PC+ TM group, and the equal volume of normal saline was given for 7 consecutive days in S group and I/R group, and endoplasmic reticulum stress agonist tunicamycin 1 mg/kg was intraperitoneally injected at 24 h before ischemia in I/R+ PC+ TM group.The mice were sacrificed at 120 min of reperfusion, and the small intestinal tissues were taken for microscopic examination of the histopathological changes (using light microscopy) and for determination of the level of diamine oxidase (DAO) (by enzyme-linked immunosorbent assay), cell apoptosis (by TUNEL method), glucose regulatory protein 78 (GRP78), C/EBP-homologous protein (CHOP) and cleaved caspase-3, Bax and Bcl-2 (by Western blot). Intestinal damage was assessed and scored according to Chiu, and the apoptosis index (AI) and Bcl-2/Bax ratio were calculated. Results:Compared with S group, the Chiu′s score, level of DAO and AI were significantly increased, the expression of GRP78, CHOP, cleaved caspase-3 and Bax was up-regulated, the expression of Bcl-2 was down-regulated, the ratio of Bcl-2/Bax was decreased( P<0.05), and the pathological damage occurred in the small intestinal tissue in I/R group, and no significant change was found in the aforementioned indexes in S+ PC group ( P>0.05). Compared with I/R group, the Chiu′s score, DAO level and AI were significantly decreased, the expression of GRP78, CHOP, cleaved caspase-3 and Bax was down-regulated, the expression of Bcl-2 was up-regulated, the ratio of Bcl-2/Bax was increased( P<0.05), and the pathological injury to the small intestinal tissue was significantly reduced in I/R+ PC group. Compared with I/R+ PC group, the Chiu′s score, level of DAO and AI were significantly increased, the expression of GRP78, CHOP, cleaved caspase-3 and Bax was up-regulated, the expression of Bcl-2 was down-regulated, and the ratio of Bcl-2/Bax was decreased( P<0.05), and the pathological damage to the small intestinal tissue was aggravated in I/R+ PC+ TM group. Conclusions:Proanthocyanidins can alleviate intestinal I/R injury by inhibiting endoplasmic reticulum stress-mediated cell apoptosis in mice.