小檗碱调控内质网应激水平影响UC结肠炎症反应的实验研究

Effect of berberine on colon inflammation by regulating endoplasmic reticulum stress levels in ulcerative colitismice mice

目的从内质网应激(ERS)角度探讨小檗碱(BBR)缓解溃疡性结肠炎(UC)结肠炎症反应的作用机制。方法 60只BALB/c小鼠按随机数字表法分为空白对照组、模型对照组和BBR低、中、高剂量组,每组12只。制备右旋葡聚糖硫酸钠诱导的UC小鼠模型,BBR低、中、高剂量组造模同时给予BBR混悬液灌胃7d。观察5组小鼠一般情况并评估疾病活动指数(DAI);末次给药后取小鼠结肠病变部位标本,进行组织病理学评价;TUNEL法检测结肠组织肠上皮细胞(IECs)的凋亡情况;免疫组化法检测结肠组织中GRP78、Caspase-12和Caspase-3蛋白的表达水平;荧光定量PCR法检测结肠组织GRP78 mRNA的表达水平。结果与模型对照组比较,BBR低、中、高剂量组小鼠结肠炎的临床症状和组织病理学损伤均有明显减轻。与空白对照组比较,模型对照组结肠组织IECs凋亡数明显增多,GRP78、Caspase-12和Caspase-3蛋白表达水平明显升高,GRP78 mRNA的表达亦上调。而与模型对照组比较,BBR低、中、高剂量组小鼠结肠组织IECs凋亡数明显下降,BBR高剂量组小鼠结肠组织GRP78、Caspase-12、Caspase-3蛋白表达水平与GRP78 mRNA的表达水平均下调。结论 BBR能有效减轻UC小鼠的结肠炎症,其机制可能与下调ERS水平。

Objective To investigate the effect of berberine hydrochloride(BBR)on colon inflammation in ulcerative colitis(UC)mice and its mechanism.Methods Sixty BALB/c mice were randomly divided into five groups:blank control group,model control group,low-dose BBR group,middle-dose BBR group and high-dose BBR group with 12 mice in each group.UC mice model was established by administration of dextran sulphate sodium(DSS).The low,middle and high doses of BBR were given by gavage for 7 days in BBR treatment groups,respectively.During the course of experiment,the general conditions of mice in five groups were observed,and disease activity index(DAI)was assessed.At the end of treatment,colon tissue specimens were sectioned and HE stained,and the histopathological assessment were performed;apoptosis of intestinal epithelial cells(IECs)was determined by TUNEL;the expression of GRP78,Caspase-12 and Caspase-3 were detected by immunohistochemical method,and the expression of GRP78 mRNA was detected by fluorescence quantitative RT-PCR.Results Compared with model control group,the clinical symptoms and pathological damage of colitis in BBR treatment groups were alleviated.Compared with blank control group,the apoptosis of IECs of colon tissue in model control group was significantly enhanced,and the expression levels of GRP78,Caspase-12 and Caspase-3 protein in colon tissue were greatly increased,and its GRP78 mRNA expression level was up-regulated;while compared with model control group,the apoptosis of IECs of colon tissue in BBR treatment groups were significantly decreased,and the expression levels of GRP78,Caspase-12 and Caspase-3,as well as GRP78 mRNA in high dose BBR group were all declined.Conclusion Berberine can effectively relieve colon inflammation in UC mice,which may be associated with down-regulation of endoplasmic reticulum stress level and inhibition of Caspase-12/Caspase-3 apoptosis signal pathway.