Differentiation of Peritubular Myoid-Like Cells from Human Induced Pluripotent Stem Cells

ABSTRACT Spermatogenesis is a complex process requiring intricate cellular interactions between multiple cell types to produce viable sperm. Peritubular myoid cells (PTMs) are smooth muscle cells that line the seminiferous tubules and play a critical role in sperm production by providing mechanical support and molecular signaling factors. In vitro investigation of their contribution to spermatogenesis and their dysfunction in infertility is currently limited by the rare accessibility of human testicular tissue for research. Therefore, this study set forth to generate an alternative source of PTMs using human induced pluripotent stem cells (hiPSCs) - adult cells that have been reprogrammed into a pluripotent state, making them capable of indefinite expansion and the regeneration of any cell type in the body. PTMs and Leydig cells arise from a common progenitor, so we hypothesized that PTMs could be derived by modifying an existing differentiation protocol for Leydig cell differentiation from hiPSCs. These hiPSC-derived cells, or hPTMs, were characterized and compared to hiPSC-derived Leydig cells (hLCs) and human primary Sertoli cells as a negative control. Our findings show that the substitution of the molecular patterning factor Platelet-Derived Growth Factor Subunit B (PDGF-BB) for Platelet-Derived Growth Factor Subunit A (PDGF-AA) in a molecule-based differentiation protocol for deriving Leydig-like cells, is sufficient to derive peritubular myoid-like cells. This study describes a method for generating PTM-like cells from hiPSCs. These cells will allow for ongoing understanding of the cellular interactions required for normal spermatogenesis in an in vitro setting.