Derivation of primodial germ cell-like cells from induced pluripotent stem cells of patients with idiopathic azoospermia

At present, the etiology of most non-obstructive azoospermia (NOA) remains unclear, and the patients are diagnosed as idiopathic infertility. 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 patients with idiopathic NOA, and differentiated them into human germline cells both in vitro and in vivo. Compared with normal hiPSCs, the idiopathic NOA patient-specific iPSCs show less efficiency of primodial germ cell-like cells (PGCLCs) formation in vitro and poor proliferation potential in vivo. Although the transcriptomes of PGCLCs are different from that of embryonic gonadal PGCs, the expression patterns of key genes involved in human PGC specification are generally similar during PGCLC induction process from all iPSCs lines, including the activation of BLIMP1, TFAP2C, NANOS3, SOX17, and T, and the repression of PRDM14 and SOX2. Moreover, the PGCLCs derived from idiopathic NOA patient-specific iPSCs initiate epigenetic reprogramming with repression of 5mC and presence of 5hmC. These findings provide a unique foundation for future mechanism research of male infertility. Transcriptome profiles of hiPSCs/hESCs, pre-induced iMeLCs, and EpCAM/INTEGRINα6 double positive PGCLCs were generated by RNA sequencing, in two replicates, by Illumina HiSeq2500.