目的 观察Bax抑制因子(Bax-inhibiting peptides,BIP)对肠上皮细胞的保护作用,并探讨其作用机制。方法 建立1日龄新生大鼠的坏死性小肠结肠炎模型。BIP于建模前腹腔内注射,建模后分别检测各组肠组织病理,并分别用流式细胞仪检测各组肠细胞凋亡率,western blot法检测bax下游凋亡蛋白细胞色素C、caspase 9和caspase 3含量。结果 与NEC组及Bax10 μg组比较,bax50 μg和100 μg可减轻肠上皮损伤,减少肠细胞凋亡率,降低bax下游凋亡蛋白细胞色素C、caspase9和caspase3含量。结论 一定剂量的Bax抑制肽可通过降低活性Caspase-3及CytC蛋白释放,保护线粒体膜,抑制肠上皮细胞调亡,发挥对肠上皮细胞的保护作用。

Objective To investigate the protective effects of Bax-inhibiting peptides(BIP) on intestinal epithelial cells and to explore its mechanism. Methods The model of neonatal necrotizing enterocolitis in 1 day neonatal rats were established. Before establishing the model, BIP was intraperitoneal injected to the rats. The pathological of intestinal tissue were detected respectively, the intestinal cell apoptosis rate were detected by flow cytometry, the levels of downstream apoptosis proteins of Bax were detected by Western blotting respectively. Results Compared to NEC and Bax10μg group, bax50μg and 100 μg can significantly reduce the intestinal epithelial damage and intestinal cell apoptosis rate and can decrease the levels of cytochrome C, caspase-9 and caspase-3, downstream apoptosis proteins of Bax,significantly. Conclusion A certain dose of Bax-inhibiting peptides can protect the mitochondrial membrane, inhibit the apoptosis of intestinal epithelial cells by reducing the level of Caspase-3 and CytC and play a protective effect on intestinal epithelial cells.