Induced Pluripotent Stem Cells Derived From Two Idiopathic Azoospermia Patients Display Compromised Differentiation Potential for Primordial Germ Cell Fate.

Fang Fang,Zhen Ye,Wenpei Xiang,Qian Zhao,Chengliang Xiong,Honggang Li,Xiuli Gu,Feng Pan,Zili Li

doi:10.3389/fcell.2020.00432

Abstract

At present, the etiology of most non-obstructive azoospermia (NOA) remains unclear. In vitro generation of patient-specific induced pluripotent stem cells (iPSCs) is an effective approach for exploring the mechanisms of human disease. Here, we established iPSCs from two patients with idiopathic NOA and differentiated them into primordial germ cell–like cells (PGCLCs) in vitro. Compared with iPSCs derived from normal fertile men, the NOA patient-specific iPSCs show decreased efficiency of PGCLC formation in vitro. Particularly, the embryoids derived from NOA patient-specific iPSCs show defects in the expression of early primordial germ cell (PGC) genes. The transcriptome analysis reveals the expression patterns of key human PGC genes are generally similar in PGCLCs differentiated from all iPSC lines, and the differentially expressed genes were enriched with gene ontology (GO) of cell cycle and apoptosis regulation. Moreover, the PGCLCs derived from NOA patient-specific iPSCs might have initiated epigenetic reprogramming at a very early stage. Thus, the NOA patient-specific iPSCs exhibit poor response to germ cell induction in vitro, which may be related to the regulation of apoptotic process. These findings provide a foundation for future research on mechanism of male infertility.

Highlights

Infertility is a widespread public health issue, and approximately 10–15% of couples at child-bearing age have difficulties in conceiving (Evers, 2002)
The human iPSCs (hiPSCs) lines derived in this study have characteristics resembling those of human ESCs (hESCs)
The results showed that these cells were positive for nuclear (OCT4, NANOG, and SOX2) and surface (SSEA4 and TRA1-60) markers of pluripotency, as well as Alkaline phosphatase (AP) (Figure 1C and Supplementary Figure S1A)

Summary

Introduction

Infertility is a widespread public health issue, and approximately 10–15% of couples at child-bearing age have difficulties in conceiving (Evers, 2002). Recent studies have reported that PGCLCs can be induced in vitro from human ESCs (hESCs) and human iPSCs (hiPSCs) in response to signals simulating the natural developing environment of PGC in vivo (Kee et al, 2009; Irie et al, 2015; Sasaki et al, 2015). Robust induction of PGCLCs from hiPSCs was established via incipient mesoderm-like cells (iMeLCs) in vitro (Sasaki et al, 2015). Based on these differentiation models, several key regulators of human PGC fate as well as the regulation network they formed were identified, including EOMES, SOX17, TFAP2C, and BLIMP1 (Irie et al, 2015; Kojima et al, 2017)

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Results

Discussion

Conclusion