CAJ | 학술논문

目的：探讨Cdx1在大鼠胚胎肛门直肠发育过程中所发挥的作用。方法应用乙烯硫脲（ ethylenethio－urea，ETU）致畸Wistar孕鼠24只肛门直肠畸形动物模型，免疫组织化学染色、RT－PCR和western blot 方法分别研究Cdx1 mRNA和Cdx1蛋白在正常和畸形大鼠胚胎泄殖腔及肛门直肠的表达。结果 Cdx1在大鼠发育过程中正常胚胎泄殖腔中表达，在第13天和第14天主要表达于尿直肠隔和泄殖腔膜，胚胎第15天时在尿直肠隔与泄殖腔膜融合处Cdx1表达较强，第16天时肛膜破裂，肛门直肠与外界相通，Cdx1在直肠黏膜层表达。 Cdx1在ARM胎鼠泄殖腔和直肠黏膜层表达较弱或呈现阴性表达。 Western blot 和 RT－PCR 半定量检测结果：在发育期的后肠中Cdx1和Cdx1 mRNA的表达表现出时间依赖性的特点：在肛门形成的关键时期Cdx1的表达水平达到高峰，一旦肛门形成其表达量随即开始降低，畸形组与正常组相比较， Cdx1蛋白半定量分析结果156?．9±23．5 vs．102．7±14．4（第14天），165．5±26．2 vs．104．5±14．6（第14．5天），153．6±19．4 vs．76．2±10．7（第15天）。 Cdx1 mRNA的表达在第14～15天明显降低差异有统计学意义（ P ＜0．05）。结论 ETU致畸的大鼠胚胎ARM肛门直肠发育过程中Cdx1／Tcf4的表达存在着时间－空间不均衡性的特点。 ETU致畸的大鼠胚胎期泄殖腔／后肠Cdx1／Tcf4表达模式的改变可能引起ARM的发生，Cdx1／Tcf4表达下调可能与ARM的发生有关。
목적：탐토Cdx1재대서배태항문직장발육과정중소발휘적작용。방법응용을희류뇨（ ethylenethio－urea，ETU）치기Wistar잉서24지항문직장기형동물모형，면역조직화학염색、RT－PCR화western blot 방법분별연구Cdx1 mRNA화Cdx1단백재정상화기형대서배태설식강급항문직장적표체。결과 Cdx1재대서발육과정중정상배태설식강중표체，재제13천화제14천주요표체우뇨직장격화설식강막，배태제15천시재뇨직장격여설식강막융합처Cdx1표체교강，제16천시항막파렬，항문직장여외계상통，Cdx1재직장점막층표체。 Cdx1재ARM태서설식강화직장점막층표체교약혹정현음성표체。 Western blot 화 RT－PCR 반정량검측결과：재발육기적후장중Cdx1화Cdx1 mRNA적표체표현출시간의뢰성적특점：재항문형성적관건시기Cdx1적표체수평체도고봉，일단항문형성기표체량수즉개시강저，기형조여정상조상비교， Cdx1단백반정량분석결과156?．9±23．5 vs．102．7±14．4（제14천），165．5±26．2 vs．104．5±14．6（제14．5천），153．6±19．4 vs．76．2±10．7（제15천）。 Cdx1 mRNA적표체재제14～15천명현강저차이유통계학의의（ P ＜0．05）。결론 ETU치기적대서배태ARM항문직장발육과정중Cdx1／Tcf4적표체존재착시간－공간불균형성적특점。 ETU치기적대서배태기설식강／후장Cdx1／Tcf4표체모식적개변가능인기ARM적발생，Cdx1／Tcf4표체하조가능여ARM적발생유관。
Objective To investigate the effect of caudal type homeobox gene-1 ( Cdx1 ) during anorectal development in normal and anorectal malformations ( ARM) embryos of rats ,and to explore its role in pathogenesis of ARM . Methods The anorectal malformation animal models were induced by ethylenethiourea ( ETU) in 24 pregnant Wistar rats , then the expression levels of Cdx 1 mRNA and Cdx1protein were detected by immunohistostaining , RT-PCR and Western Blotting in cloaca,anus,rectum of embryos of normal rats and ARM rats .Results The expression of Cdx1was found in cloaca of normal embryos,which was mainly located in dorsal urorectal septum (URS),cloacal membrane (CM) and hindgut on day 13,day 14,and the expression levels were higher in the fusion area of URS and CM on day 15,the expression of Cdx1was found in mucous membrane layer of rectum on day 16.The expression levels of Cdx1in cloaca and mucous membrane layer of rectum of ARM rat embryos were lower .The results of Western Blot and RT-PCR showed that the expression levels of Cdx 1 and Cdx1 mRNA in hindgut were time-dependent,which reached peak during anus forming ,as soon as the process was completed,the expression levels were decreased immediately .The expression levels of Cdx 1 protein in abnormality group and normal group were 156.9 ±23.5 vs 102.7 ±14.4,on day 14,165.5 ±26.2 vs 104.5 ±14.6,on day 14.5,153.6 ±19.4 vs 76.2 ±10.7, on day 15 .There was a statistical significance in the decrease of expression levels of Cdx 1 mRNA during 14~15 days ( P <0.05 ).Conclusion The spatiotemporal malconformation of expression of Cdx 1/Tcf4 exists in the process of anorectal development of ARM rat embryos induced by ETU .The changes of expression mode of Cdx 1/Tcf4 in cloaca and hindgut of ARM rat embryos induced by ETU may cause the pathogenesis of ARM , moreover , down-regulation of Cdx 1/Tcf4 may be correlated to pathogenesis of ARM .