Sertoli Cell Wt1 Regulates Peritubular Myoid Cell and Fetal Leydig Cell Differentiation during Fetal Testis Development

Qing Wen,Jixin Tang,Yuqian Wang,Yi-Xun Liu,C Yan Cheng,Ramani Ramchandran

doi:10.1371/journal.pone.0167920

Abstract

Sertoli cells play a significant role in regulating fetal testis compartmentalization to generate testis cords and interstitium during development. The Sertoli cell Wilms’ tumor 1 (Wt1) gene, which encodes ~24 zinc finger-containing transcription factors, is known to play a crucial role in fetal testis cord assembly and maintenance. However, whether Wt1 regulates fetal testis compartmentalization by modulating the development of peritubular myoid cells (PMCs) and/or fetal Leydig cells (FLCs) remains unknown. Using a Wt1-/flox; Amh-Cre mouse model by deleting Wt1 in Sertoli cells (Wt1SC-cKO) at embryonic day 14.5 (E14.5), Wt1 was found to regulate PMC and FLC development. Wt1 deletion in fetal testis Sertoli cells caused aberrant differentiation and proliferation of PMCs, FLCs and interstitial progenitor cells from embryo to newborn, leading to abnormal fetal testis interstitial development. Specifically, the expression of PMC marker genes α-Sma, Myh11 and Des, and interstitial progenitor cell marker gene Vcam1 were down-regulated, whereas FLC marker genes StAR, Cyp11a1, Cyp17a1 and Hsd3b1 were up-regulated, in neonatal Wt1SC-cKO testes. The ratio of PMC:FLC were also reduced in Wt1SC-cKO testes, concomitant with a down-regulation of Notch signaling molecules Jag 1, Notch 2, Notch 3, and Hes1 in neonatal Wt1SC-cKO testes, illustrating changes in the differentiation status of FLC from their interstitial progenitor cells during fetal testis development. In summary, Wt1 regulates the development of FLC and interstitial progenitor cell lineages through Notch signaling, and it also plays a role in PMC development. Collectively, these effects confer fetal testis compartmentalization.

Highlights

During embryogenesis, Sry expression in preSertoli cells of XY individuals turns on a genetic cascade by directing the bipotential genital ridge to develop into the testis [1]
To assess if Wilms’ tumor 1 (Wt1) deletion-induced failure in testis cord formation is mediated by perturbing the differentiation and proliferation of peritubular myoid cells (PMCs), we used PMC marker α-SMA, and proliferative marker PCNA for dual-labeled immunofluorescence analysis and quantification to assess the status of PMCs (Figs 1A, S1 and S2)
In Wt1SC-cell Wt1 knockout (cKO) testes, we observed a considerably reduction in the number of α-SMA+ PMCs from E15.5 in the remnant testis cords (Fig 1A), consistent with the declining α-SMA relative average fluorescence intensity from E15.5 (Fig 1B), and mRNA (Fig 1C) or protein (Fig 1D) levels of PMC markers in postnatal day 1 (P1) Wt1SC-cKO testes vs. control testes

Summary

Introduction

Sry (sex-determining region of the Y chromosome) expression in preSertoli cells of XY individuals turns on a genetic cascade by directing the bipotential genital ridge to develop into the testis [1]. Wt1 Regulates PMC, FLC and Interstitial Progenitor Cell Development during Fetal Testis Development cells (PMCs) [for reviews, see [2,3,4]]. Between testis cords is the interstitium, inhabited by fetal Leydig cells (FLCs), uncharacterized interstitial progenitor cells, arterial and venous blood vasculature, lymphatic vessels, resident macrophages and nerve cells [for reviews, see [2,3,4]]. Sertoli cell is thought to be the critical cell type that drives fetal testis compartmentalization [4], yet accumulating evidence has shown that FLCs and PMCs play active roles in fetal testis development. Whether Sertoli cells regulate PMC and FLC development to drive fetal testis compartmentalization is still unclear

Methods

Results

Conclusion