Expression pattern of Wif1 and β-catenin during development of anorectum in fetal rats with anorectal malformations.

Xiao Bing Tang,Wei Lin Wang,Huan Li,Yu Zuo Bai,Jin Zhang,Zheng Wei Yuan

doi:10.7717/peerj.4445

Abstract

PurposeThis study was performed to investigate the expression pattern of Wnt inhibitory factor 1 (Wif1) and β-catenin during anorectal development in normal and anorectal malformation (ARM) embryos and the possible role of Wif1 and β-catenin in the pathogenesis of ARM.MethodsARM was induced with ethylenethiourea on the 10th gestational day in rat embryos. Cesarean deliveries were performed to harvest the embryos. The expression pattern of Wif1 and β-catenin protein and mRNA was evaluated in normal rat embryos (n = 288) and ARM rat embryos (n = 306) from GD13 to GD16 using immunohistochemical staining, Western blot, and real time RT-PCR.ResultsImmunohistochemical staining revealed that in normal embryos Wif1 was constantly expressed in the cloaca from GD13 to GD16. On GD13 and GD14, Wif1-immunopositive cells were extensively expressed in the cloaca. On GD15, the expression of Wif1 were mainly detected on the very thin anal membrane. In ARM embryos, the epithelium of the hindgut and urorectal septum demonstrated faint immunostaining for Wif1 from GD14 to GD16. Western blot and real time RT-PCR revealed that Wif1 and β-catenin protein and mRNA expression level was significantly decreased in the ARM groups compared with the normal group on GD14 and GD15 (p < 0.05).ConclusionsThis study demonstrated that the expression pattern of Wif1 and β-catenin was disrupted in ARM embryos during anorectal morphogenesis, which demonstrated that downregulation of Wif1 and β-catenin at the time of cloacal separation into the primitive rectum and urogenital septum might related to the development of ARM.

Highlights

Anorectal malformations (ARM) are very common surgical disorders frequently encountered in pediatric surgery practice
In Wif1lacZ/lacZ mutant mice and cultured urorectum with exogenous Wnt inhibitory factor 1 (Wif1), cloaca septation was defective with undescended urorectal septum (URS) and hypospadias-like phenotypes (Ng et al, 2014). Both β-catenin loss- and gain-of-function (LOF and GOF) mutants displayed abnormal clefts in the perineal region and hypoplastic elongation of the URS (Miyagawa et al, 2014). These results suggest that Wif1 and β-catenin is required for urorectal development
Morphogenic events in the anorectum depend on Wif1 signal induction, and Wif1 might be important for the development of the cloacal membrane (CM) during embryogenesis of the anorectum

Summary

Introduction

Anorectal malformations (ARM) are very common surgical disorders frequently encountered in pediatric surgery practice. The incidence is approximately one in 5,000 live births. There is a wide spectrum of ARM phenotypes, ranging from stenotic anus to cloacal malformation (Endo et al, 1999). Surgical operation is the main modality of treatment. The level of ARM surgical treatment has improved, there are still different degrees of complications which seriously affect the quality of life How to cite this article Tang et al (2018), Expression pattern of Wif and β-catenin during development of anorectum in fetal rats with anorectal malformations.

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Discussion

Conclusion