Notch-1和Jagged-2基因在先天性巨结肠中的表达及意义

Expression and significance of Notch-1 and Jagged-2 in patients with Hirschsprung disease

目的研究先天性巨结肠症（HD）患儿各段肠管中Notch-1及Jagged-2的表达情况，初步探讨Notch-1及Jagged-2表达与HD发生的可能关系。方法选取2005-2010年间在中国医科大学附属盛京医院行手术治疗的HD患儿结肠标本共30例．将HD患儿正常段肠管设为对照组．移行段及痉挛段肠管设为实验组，应用免疫组织化学（免疫组化）染色、Westernblot及RT-PCR法观察Notch-1及Jagged-2在各肠段的表达情况。结果免疫组化染色示HD患儿正常段肠管的神经节细胞中有大量Notch-1及Jagged．2阳性细胞的表达．而在痉挛段肠管中没有这两种细胞的表达．移行段肠管中可见少量Notch-1及Jagged-2阳性细胞的表达。Westeinblot结果显示Notch-1和Jagged-2蛋白在痉挛段肠管相对表达量分别为0．19±0．02和0.13±0．04．明显少于移行段肠管和正常段肠管（0．58±0．05和0．52±0．04；0．72±0．04和0．69±0．04）（P〈0．05）。RT—PCR结果显示，Notch-1及Jagged-2的mRNA水平与蛋白表达一致。结论HD患儿痉挛段肠管中Notch-1及Jagged-2的表达缺失可能与HD的发生有关。

Objective To investigate the expression of Notch-1 and Jagged-2 in the normal and spastic segments of colon in patients with Hirschsprnng disease （HD）, and to explore the correlation of Notch-1 and Jagged-2 with pathogenesis of HD. Methods From 2005 to 2010, resected colon specimens of 30 cases with HD were selected for this study. Normal colonic segments were served as control group, while the transitional and spastic segments as experimental group. Immunohistochemical staining, Western blotting, and RT-PCR were applied to detect the expression of Notch-1 and Jagged-2. Results A large number of Notch-1 and Jagged-2 positive gangliocytes were observed in the control group, while none was observed in spastic segments. Significantly less Notch-1 and Jagged-2 positive gangliocytes were found in the transitional segments. Western blotting revealed that Notch-1 and Jagged-2 protein levels in spastic segments （0.19±0.02 and 0.13±0.04） were less than that in transitional segments and normal segments （0.58±0.05 and 0.52±0.04, 0.72±0.04 and 0.69±0.04, respectively） （P〈0.05）. RT-PCR revealed that Notch-1 and Jagged-2 mRNA levels were consistent with protein expression. Conclusion Notch-1 and Jagged-2 are not expressed in spastic colon segments, which may be associated with the pathogenesis of HD.