HAND2蛋白在先天性巨结肠肠壁肌间神经丛中的表达及意义

The expression and significance of HAND2 in the myenteric plexus of the colon in patients with Hirschsprung's disease

目的研究HAND2蛋白在先天性巨结肠症患儿肠壁肌间神经丛的表达情况,探讨HAND2蛋白与先天性巨结肠发病的关系。方法应用免疫组化二步法染色检测46例先天性巨结肠患儿狭窄段、移行段、扩张段和正常段肠壁组织肌间神经丛中HAND2蛋白的表达,用计算机图像分析软件(Image ProPlus 6.0)计算HAND2蛋白在先天性巨结肠各段肠壁组织肌间神经丛的免疫组化阳性染色的平均光密度值。结果 HAND2蛋白在先天性巨结肠患儿正常肠壁组织的肌间神经丛有阳性表达,多呈强阳性;环形肌及纵行肌亦有表达,多呈中等强度阳性。狭窄段肌间神经丛中,未见有阳性染色的神经节细胞,可见肌间神经纤维表达呈弱阳性或阴性;在移行段与扩张段肌间神经丛中,可见较多阳性表达肌间神经节或神经纤维。分别与移行段、扩张段及正常段比较,狭窄段的平均光密度明显降低,差异有统计学意义(P<0.01)。结论狭窄段肠壁肌间神经丛中HAND2蛋白表达量降低,HAND2蛋白表达改变可能是先天性巨结肠的发病因素之一。

Objective To investigate the expression of HAND2 in the myenteric plexus of the colon in patients with Hirschsprung＇s disease （HD）, thus to study correlation between HAND2 and pathogenesis of HD. Methods The aganglionic, transitional, dilated and normal segments from the resected colon specimens of 46 patients with HD were col- lected for study. Immunohistochemistry was applied to assess the protein expression of HAND2. Results In normal seg- ments, HAND2 was strong positive in the myenteric plexus and median positive in muscle layers, including circular and longitudinal layers. No HAND2 positive ganglion cell was observed in the myenteric plexus in aganglionie segments, though weak positive or negative nerve fibers could be observed. HAND2 positive myenteric plexus were also observed in the transitional and dilated segments. Significant reduction in optical density of HAND2 was revealed in myenteric plexus in aganglionic segments when comparing with those in transitional, dilated and normal segments （P 〈 0. 01 ）. Conclusion HAND2 is down - regulated in the myenteric plexus of the aganglionic segment of HD patients, suggesting it is involved its pathogenesis.