微小RNA-129调控N-乙酰氨基半乳糖基转移酶1/转化生长因子-β1信号通路对慢传输型便秘的作用及其机制

The effect and mechanism of microRNA-129 in regulating N-acetylgalactosaminyltransferase 1/transforming growth factor-β1 signaling pathway in slow transit constipation

目的探讨微小RNA(miRNA,miR)-129通过N-乙酰氨基半乳糖基转移酶1(GALNT1)/转化生长因子-β1(TGF-β1)信号转导通路影响慢传输型便秘(STC)发生的机制。方法共纳入46例患者28例为重度结肠STC患者,18例为非STC患者)。采用免疫组织化学技术检测结肠组织中Cajal间质细胞(ICC)的形态及数量,Western blot检测结肠组织中GALNT1/TGF-β1信号通路的表达/活化水平。结果免疫组织化学结果显示,STC病变结肠各个区域c-Kit标记的ICC细胞数较对照组显著减少(22.17±3.28比28.69±3.53,P<0.05),并且分布异常。同时Western blot结果显示STC组c-Kit蛋白、Smad6/7较正常组显著下降(c-Kit:0.462±0.099比0.783±0.178,P<0.01);(Smad6/7:0.626±0.058,比0.799±0.035,P<0.01);TGF-β1在两组差异无统计学意义(0.476±0.028比0.511±0.044,P>0.05)。结论STC病变结肠中ICC细胞可能发生细胞转分化,从而使病变结肠中ICC分布和功能异常。其分子机制明显是miR-129负调控GALNT1/TGF-β1信号转导通路,并与Smad6/7抑制作用下降相关。

Objective To discuss that microRNA (miRNA, miR)-129 influence the occurrence of slow transit constipation (STC) through N-acetylgalactosaminyltransferase 1 (GALNT1)/transforming growth factor-β1 (TGF-β1) pathway. Methods Included 46 patients (28 cases of patients with STC, 18 cases of normal colon tissue). Using Immunohistochemistry to detect the form and quantity of the interstitial cell of Cajal (ICC), using Western blotting to detect the expression/activation levels of GALNT1/TGF-β1 pathway. Results Immunohistochemistry shows that the number of ICC marked by c-Kit was significantly reduced in the colon of STC (22.17±3.28 vs. 28.69±3.53, P<0.05), and the distribution was abnormal. Western blotting revealed that the expression of protein c-Kit and Smad6/7 decreased significantly in the colon of STC (c-Kit: 0.462±0.099 vs. 0.783±0.178, P<0.01);(Smad6/7: 0.626±0.058 vs. 0.799±0.035, P<0.01). But there was no obvious difference in the expression of protein TGF-β1 (0.476±0.028 vs. 0.511±0.044, P>0.05). Conclusion The conversion of ICC may occur in the colon of STC, which led to the abnormities of the distribution and function. The molecular mechanism obviously was related to the GALNT1/TGF-β1 pathway which was regulated by miR-129, and related to the decrease of the inhibitory effect of the protein Smad6/7.