电针对溃疡性结肠炎大鼠肠黏膜维生素D受体表达的影响

Electroacupuncture Has an Effect on Expression of Vitamin D Receptor of Intestinal Mucosa of Rats with Colitis

目的:观察电针天枢、上巨虚穴对结肠炎大鼠肠黏膜中维生素D受体(VDR)表达的影响,探讨电针治疗溃疡性结肠炎(UC)的可能机制。方法:按照随机数字表法将雄性Wistar大鼠分为对照组、模型组和电针组,每组8只。采用三硝基苯磺酸(TNBS)灌肠的方法来诱导溃疡性结肠炎制备大鼠模型,同时采用大鼠疾病活动指数(DAI)评分和组织学活动度评分(HAI)来评估结肠炎症程度。电针组大鼠经TNBS造模成功后次日取天枢、上巨虚穴进行电针治疗,共14 d。于第15天处死大鼠后收集结肠组织,分别采用免疫组化和实时荧光定量PCR法(qRT-PCR)检测肠黏膜VDR的表达水平,采用分光光度法测定结肠组织髓过氧化物酶(MPO)活性。结果:与模型组比较,电针组HAI明显下降(P=0.005)。与对照组比较,模型组和电针组结肠组织中MPO活性均明显增加。与模型组比较,电针组结肠组织中MPO活性下降(P<0.001)。与对照组比较,模型组、电针组大鼠肠黏膜中VDR mRNA及蛋白表达降低(P<0.01)。与模型组比较,电针组大鼠肠黏膜VDR m RNA及蛋白表达升高(P<0.05)。蛋白免疫组化提示VDR主要在上皮细胞中表达。VDR蛋白表达水平与MPO活性成负相关(P<0.05)。结论:电针天枢、上巨虚两穴可能通过上调肠黏膜VDR表达来缓解大鼠UC症状。

Objective:To observe the effect of electroacupuncture at Tianshu point(ST 25) and Shangjuxu point(ST 37) on the expression of vitamin D receptor(VDR) of intestinal mucosa of rats with colitis,and to discuss the possible mechanism of electroacupuncture in the treatment of ulcerative colitis(UC). Methods:Male Wistar rats were divided into the control group,the model group and the electroacupuncture group according to the random number table method,eight rats in each group.The rat models of UC were induced by enema with trinitrobenzene sulfonic acid(TNBS). Meanwhile,Disease Activity Index(DAI) and Histology Activity Index(HAI) were used to evaluate the degree of colitis. In the electroacupuncture group,rats were given electroacupuncture at Tianshu point(ST 25) and Shangjuxu point(ST 37) for 14 days, started from the next day after successful TNBS modeling. The colonic tissues were collected after the rats were sacrificed on the 15 thday. The expression level of VDR of intestinal mucosa was measured by immunohistochemistry and real-time quantitative reverse transcriptionPCR(qRT-PCR). Myeloperoxidase(MPO) activity in colonic tissue was measured by spectrophotometry. Results: When compared with that in the model group, HAI in the electroacupuncture group was obviously decreased(P=0.005). When compared with that in the control group,the activity of MPO in colonic tissue in the model group and the electroacupuncture group were significantly increased. The activity of MPO in colonic tissue in the electroacupuncture group was decreased when compared with that in the model group(P<0.001). The expression of mRNA and protein of VDR in intestinal mucosa in the model group and the electroacupuncture group was decreased when compared with that in the control group(P<0.01). The expression of mRNA and protein of VDR in intestinal mucosa in the electroacupuncture group was decreased when compared with that in the model group(P<0.05). Protein immunohistochemistry suggested that VDR was mainly expressed in epithelial cells. The expression level of protein of VDR inversely correlated with MPO activity(P<0.05). Conclusion: The electroacupuncture at Tianshu point(ST 25) and Shangjuxu point(ST 37) may help relieve UC of rats by up-regulating the expression of VDR in intestinal mucosa.