Temporal and spatial expression of caudal-type homeobox gene-1 in the development of anorectal malformations in rat embryos
Temporal and spatial expression of caudal-type homeobox gene-1 in the development of anorectal malformations in rat embryos
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DOI：
10.1016/j.jpedsurg.2008.10.002
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发表时间：
2009-08-01
影响因子：
2.4
通讯作者：
Wang, Wei Lin
中科院分区：
文献类型：
--
作者：
Zhang, Tao;Bai, Yu Zuo;Wang, Wei Lin
目的：本研究的目的是确定尾部型同源异型盒基因-1（Cdx 1）的表达在肛门直肠发育过程中的正常和肛门直肠畸形（ARMs）胚胎，并探讨Cdx 1的发病机制中可能发挥的作用ARM.Materials和方法：肛门直肠畸形诱导的乙撑硫脲在妊娠第10天（GD 10）在大鼠胚胎。从GD 13至GD 21进行剖腹产以收获胚胎。采用免疫组织化学染色、逆转录聚合酶链反应（RT-PCR）和Western blot分析方法，对正常大鼠胚胎（n = 334）和ARM胚胎（n = 328）在GD 13 ~ GD 20的时间和空间表达进行了研究。免疫组化结果显示，在正常胚胎中，GD13.5，Cdx 1主要表达于尿直肠隔背侧（URS）、泄殖腔膜、和后肠在GD 15，在URS的融合组织上观察到阳性组织染色增加，特别是在非常薄的肛膜中。然而，在ARM胚胎中，泄殖腔、URS和肛门直肠的上皮细胞对Cdx 1呈阴性或微弱。Western blot和RT-PCR结果显示，在正常组中，Cdx 1蛋白和Cdx 1 mRNA的表达在GD 14、GD14.5和GD 15的后肠发育过程中呈现时间依赖性变化。当肛门形成时，表达水平达到顶峰。一旦肛门打开，Cdx 1的表达逐渐下降。结论：在ARM胚胎中，Cdx 1在GD 13 ~ GD 16的肛门直肠形态发生过程中存在时空表达失衡。这表明，在泄殖腔分离到直肠和尿道时Cdx 1的下调可能与ARM的发展有关。All rights reserved.
Purpose: The aim of this study was to determine caudal-type homeobox gene-1 (Cdx1) expressions during anorectal development in normal and anorectal malformation (ARMs) embryos and investigate the possible role of Cdx1 in the pathogenesis of ARM.Materials and methods: Anorectal malformation was induced by ethylenethiourea on the 10th gestational day (GD10) in rat embryos. Cesarean deliveries were performed to harvest embryos from GD13 to GD21. The temporal and spatial expression of Cdx1 was evaluated in normal rat embryos (n = 334) and ARM embryos (n = 328) from GD13 to GD20 using immunohistochemistry staining, reverse transcriptase polymerase chain reaction (RT-PCR), and Western blot analysis.Results: Immunostaining revealed that in normal embryos, on GD13.5, Cdx1 expression was mainly located on the epithelium of the dorsal urorectal septum (URS), cloacal membrane, and the hindgut. On GD15, increased positive tissue staining was noted on the fused tissue of URS, especially in the very thin anal membrane. In the ARM embryos, however, the epithelium of the cloaca, URS, and anorectum was negative or faint for Cdx1. In Western blot and RT-PCR, in the normal group, Cdx1 protein and Cdx1 messenger RNA expression showed time-dependent changes in the developing hindgut, on GD14, GD14.5, and GD15. The expression level reached a peak when the anus was forming. Once the anus was open, Cdx1 expression gradually decreased. In addition, the expression level of Cdx1 in the ARM group from GD13 to GD16 was significant lower than that of the normal group (P < .05).Conclusions: In ARM embryos, an imbalance of spatiotemporal expression of Cdx1 was noted during anorectal morphogenesis from GD13 to GD16. This suggests that downregulation of Cdx1 at the time of cloacal separation into rectum and urethra might be related to the development of ARM. (C) 2009 Elsevier Inc. All rights reserved.