维甲酸致大鼠肛门直肠畸形中Hoxd-13基因表达的研究  

The expression of Hoxd-13 in rat embryos with anorectal malformations induced by all-trans retinoic acid

作　　者：郭俊斌[1] 张志波[2] 王练英[2] 李昭铸[1] 

机构地区：[1]哈尔滨医科大学附属第二医院小儿外科,150086 [2]中国医科大学盛京医院小儿外科

出　　处：《中华小儿外科杂志》2008年第5期306-310,共5页Chinese Journal of Pediatric Surgery

基　　金：国家自然科学基金资助（编号：300310370）

摘　　要：目的探讨Hoxd-13基因表达与大鼠肛门直肠畸形形成之间的相关性。方法维甲酸制作大鼠肛门直肠畸形动物模型，分别于妊娠第12、13、14、16、18、20d时行剖宫取仔，所得标本部分行HE染色观察，各组切片均根据HE染色结果选取2～3张进行Hoxd-13基因表达的原位杂交检测，并对Hoxd-13基因表达部位和强度（平均灰度值G值表示）进行统计学分析。结果胚胎学研究表明实验组胚胎从妊娠12d时发育即较对照组延迟，随时间延长畸形逐步发展，到妊娠16d时，肛门直肠畸形、显性脊柱裂和尾畸形已经形成。对照组胚胎中Hoxd-13基因表达在肛门直肠和泌尿生殖系未完全形成之前的泌尿直肠隔下方的泄殖腔内层和原始的后肠内层，实验组则缺如。表达水平（G值）经统计方差分析，差异具有统计学意义（F=23．165，P〈0．05）。各组均数两两对比结果显示对照组中除妊娠12d时灰度值稍高外，其余各组间无明显差异，灰度值均值随妊娠天数增加呈降低趋势，即表达有增强趋势；实验组规律则不甚明显，但总体上仍呈灰度值降低、表达增强趋势。结论在泄殖腔结构转化过程中泄殖腔和后肠内皮处Hoxd-13基因表达缺如与肛门直肠畸形形成相关，Hox基因可能是维生素A信号系统产生肛门直肠畸形的下游基因。Objective To explore the relationship between the expression of Hoxd-13 gene and the development of the anorectal malformations （ARMs） in rat embryos. Methods The fetuses were gained by Caesarean section on El2, El3, El4, El6, E18 and E20. All samples were processed, embedded and serially sliced at 6 um sagittally. Some slices were stained with H-E and were examined microscopically. The expression of Hoxd-13 was determined by ISI-I according to the results of HE stained slices. The images were analyzed with Meta Morph software, and the levels of gene expression were recorded as average gray value （G-value）. Results Histological examination showed the ARMs embryos developed more slowly than control groups since El2. On El6, the ARMs, spinal bifida and tail deformities had formed. The expression of Hoxd-13 was noted in the endothelium of cloaca and hindgut before anorectal and urogenital system formed in control groups. However, there was no expression of this gene in the ATRA treated groups. The G-values in the ATRA treated groups were significantly lower than those in control groups （F= 23. 165 ,P〈0. 05）. The highest G-value was noted at E12,and it decreased with the increase of gestation day in control groups. However, the relationship between the G- values and gestation day was not clear in ATRA treated groups. Conclusions The absence of the Hoxd-13 gene expression in the endothelium of cloaca and hindgut may be related to the development of ARMs. Hox genes may be the downstream genes of Vitamin A signaling pathway.

关 键 词：肛门 畸形 直肠 畸形 基因 HOX 维甲酸 

分 类 号：R726.5[医药卫生—儿科]