目的:观察艾灸对葡聚糖硫酸钠(DSS)诱导的溃疡性结肠炎(UC)大鼠结肠黏膜屏障的影响.方法:将雄性Sprague-Dawley大鼠40只随机分成正常组和造模组,每组20只.造模组大鼠连续7 d饮用4%DSS建立实验性大鼠UC模型.随机选取造模大鼠2只,正常大鼠2只用于模型鉴定.确认UC模型成功后,将剩余18只造模大鼠随机分为3组,即模型组、模型+隔药灸组和模型+温和灸组,每组6只;将剩余的正常大鼠随机分为3组,即正常组、正常+隔药灸组和正常+温和灸组,每组6只.隔药灸、温和灸均干预7 d后采用苏木素-伊红(HE)染色技术,在光镜下观察结肠组织病理变化情况;采用免疫印迹法和/或免疫组化技术检测大鼠结肠组织咬合蛋白(Occludin)、闭合蛋白(Claudin)、结合黏附分子1(JAM1)、黏蛋白2(MUC2)和转化生长因子β1(TGF-β1)蛋白的表达.结果:与正常组相比,模型组结肠组织损伤严重,病理学评分显著升高,Occludin、Claudin、JAM1、MUC2和TGF-β1蛋白表达显著降低(P<0.01);正常+隔药灸组和正常+温和灸组大鼠的结肠组织病理学评分,Occludin、Claudin、JAM1、MUC2和TGF-β1蛋白表达均无明显变化(P>0.05).与模型组相比,模型+隔药灸组和模型+温和灸组结肠组织损伤修复,溃疡愈合,病理学评分显著降低,JAM1、MUC2和TGF-β1蛋白表达显著升高(P<0.05),模型+温和灸组结肠组织Occludin蛋白表达升高(P<0.01).结论:隔药灸和温和灸均未对正常大鼠的结肠组织病理学和肠黏膜屏障相关蛋白表达产生影响;隔药灸和温和灸均能上调UC大鼠结肠组织JAM1、MUC2和TGF-β1蛋白表达,温和灸能上调Occludin蛋白表达,这可能是艾灸减轻UC结肠黏膜炎症的作用机制之一.
Objective: To observe the effect of moxibustion on the colonic mucosal barrier of rats with ulcerative colitis (UC) induced by dextran sulfate sodium (DSS). Methods: Forty male Sprague-Dawley rats were randomly divided into a normal group and a modeling group, with 20 rats in each group. Rats in the modeling group were subjected to preparing experimental UC models by drinking 4% DSS for seven consecutive days. Two modeled rats and two normal rats were randomly selected for model identification. After the success of UC model was confirmed, the remaining 18 modeled rats were randomly divided into three groups, a model group, a model + herbal cake-partitioned moxibustion group, and a model + mild moxibustion group, with six rats in each group; the remaining normal rats were randomly divided into three groups, a normal group, a normal + herbal cake-partitioned moxibustion group, and a normal + mild moxibustion group, with six rats in each group. After 7 d of intervention with the herbal cake-partitioned moxibustion or the mild moxibustion, hematoxylin-eosin (HE) staining technique was used to observe the pathological changes of colon tissue under a light microscope; Western blotting and/or immunohistochemical techniques were used to detect the protein expression levels of Occludin, Claudin, junction adhesion molecular 1 (JAM1), mucin 2 (MUC2), and transforming growth factor beta1 (TGF-β1) in rat colon tissue. Results: Compared with the normal group, the colon tissue was severely damaged, the pathological score was significantly increased, and the protein expression levels of Occludin, Claudin, JAM1, MUC2, and TGF-β1 were significantly decreased in the model group (P<0.01); while there were no significant differences in the colonic histopathological score, protein expression levels of Occludin, Claudin, JAM1, MUC2, and TGF-β1 in the normal + herbal cake-partitioned moxibustion group and the normal + mild moxibustion group (P>0.05). Compared with the model group, the model + herbal cake-partitioned moxibustion group and the model + mild moxibustion group showed repaired colon tissue, ulcer healing, significantly reduced pathological score, and significantly increased protein expression levels of JAM1, MUC2, and TGF-β1 (P<0.05); the Occludin protein expression level in the colon tissue of the model + mild moxibustion group was increased (P<0.01). Conclusion: Neither herbal cake-partitioned moxibustion nor mild moxibustion influences the colonic histopathology and intestinal mucosal barrier-related protein expression in the normal rats; both herbal cake-partitioned moxibustion and mild moxibustion can up-regulate the protein expression levels of JAM1, MUC2, and TGF-β1 in the colon tissue of UC rats. Mild moxibustion can up-regulate Occludin protein expression. This may be a mechanism of moxibustion in reducing colonic mucosa inflammation in UC.