马齿苋多糖干预大鼠溃疡性结肠炎Caspase-3 Caspase-8表达的研究

The POP Interfered with the Expression of Caspase-3 and Caspase-8 in a Rat Experimental Model of TNBS-Induced Colitis

目的:观察大鼠溃疡性结肠炎结肠黏膜上皮细胞凋亡及其凋亡关键酶Caspase-3、Caspase-8的表达,以及马齿苋多糖对上述指标的影响,探讨马齿苋多糖干预溃疡性结肠炎的效应机制。方法:48只雄性SD大鼠按体重随机分为正常组、模型组、治疗组,对照组,每组12只。用5%2,4,6TNBs100mg/kg灌肠建立大鼠UC模型,第3天开始,除正常组外,各组分别给予等剂量0.9%氯化钠、马齿苋多糖,惠迪(美沙拉嗪)处理,连续给药7天后处死动物。应用HE染色结合肉眼评价各组大鼠组织病理学变化;应用TUNEL染色技术检测结肠上皮细胞凋亡率;应用免疫组化染色技术检测Caspase-3、Caspase-8阳性表达。结果:结肠组织形态学评分表明,治疗组与对照组比较,无统计学意义(P>0.05);治疗组与模型组相比,有统计学意义(P<0.01)。治疗组结肠黏膜上皮细胞凋亡呈下降趋势,与模型组比较,有统计学意义(P<0.05);与对照组比较,无统计学意义(P>0.05)。治疗组Caspase-3、Caspase-8蛋白阳性表达减少,与模型组比较,有统计学意义(P>0.05);与对照组比较,无统计学意义(P>0.05)。结论:马齿苋多糖可能通过下调结肠黏膜上皮细胞凋亡关键调控酶Caspase-3、Caspase-8的表达,延缓肠上皮细胞凋亡,促进肠黏膜屏障修复,发挥缓解溃疡性结肠炎的效应。

Objective：To observe the colon epithelial cell apoptosis and the expression of its key regulatory enzyme caspase-3 and caspase-8 in a TNBs-induced ulcerative colitis as well as to survey the influence of polysaccharide of Portulaca oleracea （POP） on UC. Methods：48 rats were randomly divided into four groups according to weight. Each group consisted of twelve rats,group（1）：normal; group（2）：blank; group（3）：intervention; group（4）：control.The rat model of ulcerative colitis was brought about by an enema of 100 mg/kg of TNBS and 50% ethanol. Beginning from the third day,except for the normal group,each group was treated with an enema of 0.9% NACL,POP,Mesalazine respectively. The rats were sacrificed 1 week later. The changes of pathology were detected by HE stains and naked eyes. The rate of colon epithelial cell apoptosis was assayed by TUNEL stains. The expression of caspase-3、caspase-8 protein was analyzed by IHC stains.Results：According to the score of HE stains,there is a significant difference in the changes of histomorphology between intervention group and blank group（P〈0.01）. But,there is no significant difference between intervention group and control group. Compared to blank group,the rate of the colon epithelial cell apoptosis is on the decline in intervention group（P〈0.05）. But,There is no significant difference between intervention group and control group（P〉0.05）.Compared to blank group,the expression of caspase-3、caspase-8 protein was on the decrease in intervention group also（P〈0.05）. However,There is no significant difference between intervention and control group（P〈0.05）.Conclusions：The POP show to an exact effect on the rat model of UC possibly by decreasing the expression of caspase-3 and caspase-8 on colon epithelial cell as well as delaying the colon epithelial cell apoptosis.