Germ Line Stem Cells: A Promising Alternative Source for Stem-Cell-Based Therapies in Regenerative Medicine

Abstract

Spermatogonial stem cells (SSCs) are exceptional cells with potential clinical applications in fertility preservation and regenerative medicine. Like other tissue-specific stem cells, SSCs are defined by their ability to balance between self-renewal and differentiation. This balance regulates the stem cell pool and guarantees the daily production of gametes. The preservation and transplantation of SSCs may become a promising strategy to treat reproductive stem cell loss disorders. As a consequence, the banking of testicular tissue from prepubertal patients is being introduced in a clinical setting. Moreover, with the increasing reports about the plasticity of mouse and human SSCs, their potential application in regenerative medicine is highly interesting. In contrast to males, females are born with a finite population of primordial follicles. Although the existence of ovarian stem cells (OSCs) has been suggested recently, it is still a matter of controversy. This review provides an update on the role of germ line stem cells in fertility restoration after germ cell loss, and gives an overview of (future) clinical applications making use of these fascinating cells.