[Stem cell therapy for non-obstructive azoospermia].

Non-obstructive azoospermia (NOA) is an important factor that causes male infertility. Stem cells are a group of cells capable of self-renewal and multi-directional differentiation, and embryonic stem cells and induced pluripotent stem cells can generate spermatozoa through differentiation, which, however, is confronted with ethical constraints and the risk of tumorigenesis. Spermatogonial stem cells can produce haploid gametes by differentiation but human spermatogonial stem cells are difficult to be cultured in vitro. Mesenchymal stem cells promote spermatogenesis through paracrine activity, and Leydig stem cells act on sperm production by secreting testosterone. 2D co-culture of multiple stem cells and 3D testicular organ culture can promote spermatogenesis by simulating a better spermatogenic microenvironment of the testis. Some progress has been achieved in the treatment of NOA by stem cell therapy despite existing problems and difficulties. This review summarizes the advances in the studies of stem cell therapy for NOA and introduces its application prospects and existing problems so as to provide some reference for the relevant researches and application.