[Effect of electroacupuncture on Notch/NF-κB signaling pathway in colonic mucosa of mice with ulcerative colitis].

To observe the protective effect of electroacupuncture (EA) on the intestinal mucosal barrier and its relationship with the Notch/NF-κB signaling pathway in mice with ulcerative colitis (UC), so as to explore its mechanism of treating UC.Male C57BL/6J mice were randomized into control, model and EA groups, with 6 mice in each group. The UC model was established by giving the mice with 2% Dextran Sulfate Sodium (DSS) for 7 days. EA (2 Hz/15 Hz, 0.2 mA) was applied at bilateral "Zusanli" (ST36) for 30 min, once a day for 7 days. The disease activity indexes ［DAI=(body weight index score+stool score+bleeding score)/3; 0-4 points］ of mice were calculated. The morphological changes of colonic tissues of mice in each group were observed by HE staining, and serum contents of TNF-α and IL-6 were detected by ELISA. Claudin-1 protein expression in colon tissue was detected by immunofluorescence, while the protein expression levels of Muc-2, Notch-1, MMP-9 in colon tissue were detected by immunohistochemistry. The real-time PCR method was used to detect the expression levels of Notch-1, Hes-1, NF-κB, TLR-4 and AKT mRNA in colon tissues.After modeling, the DAI, serum TNF-α and IL-6 contents, Notch-1 and MMP-9 protein expression, the relative expression levels of Notch-1, Hes-1, NF-κB, TLR-4 and AKT mRNA in the colonic tissue were significantly increased (P<0.001, P<0.01) in the model group relevant to the control group. At the same time, Claudin-1 and Muc-2 protein expression were significantly reduced (P<0.01). After the EA intervention, the increased DAI score, TNF-α and IL-6 contents, Notch-1 and MMP-9 protein expression, the relative expressions of Notch-1, Hes-1, NF-κB, TLR-4 and AKT mRNA, and the decreased Claudin-1 and Muc-2 protein expression were all reversed compared with the model group (P<0.05, P<0.01, P<0.001). H.E. staining of the colonic tissue showed damage and infiltration of inflammatory cells in the model group, and those were significantly improved in the EA group.EA can promote the recovery of intestinal mucosal barrier function and reduce inflammatory reaction in UC mice, which may be associated with its effects in inhibiting the excessive activation of the Notch/NF-κB signaling pathway.目的：观察电针对溃疡性结肠炎（UC）模型小鼠肠黏膜屏障的保护作用及其对Notch/NF-κB信号通路的影响，探讨电针治疗UC的相关机制。方法：雄性C57BL/6J小鼠采用葡聚糖硫酸钠饮用法复制UC模型，造模成功后随机分为模型组、电针组，每组6只，另设6只为空白组。电针组给予电针“足三里”治疗，每日30 min，连续治疗7 d。观察各组小鼠的一般情况，进行疾病活动指数(DAI)评分，采用HE染色法观察各组小鼠结肠组织形态变化，ELISA法检测小鼠血清中肿瘤坏死因子(TNF-α)、白细胞介素(IL)-6含量，免疫荧光法检测结肠组织Claudin-1蛋白表达，免疫组织化学法检测结肠组织黏液蛋白(Muc)-2、Notch-1、基质金属蛋白酶(MMP)-9蛋白表达，实时荧光定量PCR法检测结肠组织Notch-1、Hes-1、核转录因子（NF)-κB、Toll样受体（TLR）-4、蛋白激酶B(AKT) mRNA含量。结果：与空白组比较，模型组小鼠DAI评分升高(P<0.001)，血清中TNF-α、IL-6含量增加(P<0.01,P<0.001)，结肠组织中Claudin-1、Muc-2蛋白阳性表达均减少(P<0.01)，Notch-1、MMP-9蛋白阳性表达及Notch-1、Hes-1、NF-κB、TLR-4、AKT mRNA相对表达量均升高(P<0.01，P<0.001)。与模型组比较，治疗后电针组DAI评分降低(P<0.05)，血清中TNF-α、IL-6含量降低(P<0.01,P<0.001)，结肠组织中Claudin-1、Muc-2蛋白阳性表达均增加(P<0.05)，Notch-1、MMP-9蛋白阳性表达及Notch-1、Hes-1、NF-κB、TLR-4、AKT mRNA相对表达量均降低(P<0.05，P<0.01，P<0.001)。HE染色结果显示，空白组小鼠结肠上皮完整，杯状细胞丰富，无炎性细胞浸润；模型组结肠黏膜结构模糊，存在大小不等的缺损，杯状细胞脱落，炎性细胞大量浸润；电针组结肠损伤较模型组明显改善。结论：电针能促进UC模型小鼠肠黏膜屏障功能的恢复，减轻炎性反应，其作用机制可能与抑制Notch/NF-κB信号通路的过度活化相关。.