RET基因与GDNF基因在先天性巨结肠中的蛋白表达

The expression of RET and GDNF gene in hirschsprung' s disease

目的以免疫组化方法检测HD中RET、GDNF蛋白水平的表达,探讨其在HD肠道神经中的分布及其作用。方法21例HD患者全层肠标本,免疫组化使用抗RET、抗GDNF及磷酸化酪氨酸(p-Tyr)抗体,生物素-亲合素-碱性磷酸酶系统。对照组采用5例年龄匹配非HD患者的结肠标本。结果在对照组结肠与HD正常段肠管肌间丛、粘膜下丛神经节细胞胞浆可见抗RET、抗GDNF强阳性染色;移行段神经节细胞染色强度弱于正常段神经节细胞;痉挛段肌间丛、粘膜下丛无RET、GDNF阳性细胞;在HD正常段、移行段肠管粘膜腺体上皮细胞胞浆可见GDNF红染,多位于腺腔上中部,肌间丛内细胞间有抗GDNF阳性染色。结论RET与GDNF在HD正常段、移行段与痉挛段表达逐渐减少,与HD肠神经节细胞缺乏相吻合,提示HD病变肠段既存在酪氨酸激酶受体的缺陷,也可能存在神经营养因子的异常。

Objective:Hirschsprung' s disease(HD)is a inherited disorder.The aim of th is study was to investigate the patte rn of RET and GDNF expression in various colonic segments of Hirschsprung' s disease a nd understand their roles in enteric inner-vation.Methods :21HD cases(aged 3months to 5years)and 5age -matched controls were involved in the study.I mmunohistochemistry was performed by using avidin -biotin -peroxidase complex methods with anti -RET?anti -p -Tyr and anti -GDNF antibodies.Results:A h igh level of RET -and GDNF -expression,together with moderate level of p -Ty r ex-pression,were found in normal colon and ganglionic segment of HD.In the h ypoganglionic segment of HD,three a ntibodies im-munoreactivity was all redu ced comp ared with proximal normalganglioni c seg -ment.The RET and GDNF immun ore activity absent in aganglionic segment.There was strong GDNF immunoreativi ty in the mucosal epithelium cells in normal colo n and ganglionic segment of HD ,mainly situating towa rds to the apex of crypts.Conclusion:Reduced level of RET and GDNF protein expression suggest that either deficit of GDNF e xpression or disfunction of RET rece ptor are invovelment with the pathogeneis of HD.The progressive decrease of RET and GDNF protein expression in various colon ic segm ents of HD was in accordanced w ith innervation of entric ganglions.