Efficient differentiation of human iPSCs into Leydig-like cells capable of long-term stable secretion of testosterone.

Late-onset hypogonadism (LOH) syndrome is characterized by age-related testosterone deficiency and negatively affects the quality of life of older men. A promising therapeutic approach for LOH syndrome is transplantation of testosterone-producing Leydig-like cells (LLCs) derived from human induced pluripotent stem cells (hiPSCs). However, previous studies have encountered obstacles, such as limited cell longevity, insufficient testosterone production, and inefficiency of differentiation. To address these issues, we developed a novel protocol that includes forced NR5A1 expression, a cytokine cocktail promoting mesoderm differentiation, and a transitional shift from 3D to 2D cultures. The resultant cells survived on culture dishes for over 16 weeks, produced 22-fold more testosterone than the conventional method, and constituted a homogeneous population of LLCs with a differentiation efficiency exceeding 99% without purification. Furthermore, these LLCs were successfully engrafted subcutaneously into mice, resulting in increased serum testosterone levels. Our study will facilitate innovative therapeutic strategies for LOH syndrome.