Testicular endothelial cells promote self-renewal of spermatogonial stem cells in rats†

Abstract

Spermatogonial stem cells (SSCs) are the basis of spermatogenesis in male due to their capability to multiply in numbers by self-renewal and subsequent meiotic processes. However, as SSCs are present in a very small proportion in the testis, in vitro proliferation of undifferentiated SSCs will facilitate the study of germ cell biology. In this study, we investigated the effectiveness of various cell lines as a feeder layer for rat SSCs. Germ cells enriched for SSCs were cultured on feeder layers including SIM mouse embryo-derived thioguanine and ouabain-resistant cells, C166 cells, and mouse and rat testicular endothelial cells (TECs) and their stem cell potential for generating donor-derived colonies and offspring was assessed by transplantation into recipient testes. Rat germ cells cultured on TECs showed increased mRNA and protein levels of undifferentiated spermatogonial markers. Rat SSCs derived from these germ cells underwent spermatogenesis and generated offspring when transplanted into recipients. Collectively, TECs can serve as an effective feeder layer that enhances the proliferative and self-renewal capacity of cultured rat SSCs while preserving their stemness properties.

Proteomic analysis and miRNA profiling of human testicular endothelial cell-derived exosomes: the potential effects on spermatogenesis

“…The role of Leydig cells, peritubular myoid cells, and Sertoli cells during the process of sperm production has been confirmed by a large number of studies, 16 17 26 but only a few studies have focused on the testicular endothelial cells. 13 14 Evidence that endothelial cells can organ-specifically regulate developmental processes and maintain normal organ homeostasis by generating tissue-specific secretomes has been mounting. 14 27 28 Soluble factors released by cerebral endothelial cells could promote the self-renewal and inhibit the differentiation of neural stem cells while promoting the production of neurons.…”

“… 30 TECs, as a niche of germline stem cells, have also been proven to enhance the proliferation and self-renewal of spermatogonial stem cells. 13 14 …”

“…Testicular endothelial cells (TECs) are the key population in the male germline stem cell niche and are situated close to the blood–testis barrier (BTB) 13 TECs can contribute to the self-renewal and maintenance of spermatogonial stem cells (SSCs), which are considered to have a significant role in spermatogenesis, through upregulation of glial cell line-derived neurotrophic factor (GDNF), insulin-like growth factor-binding protein 2 (IGFBP-2), macrophage inflammatory protein 2 (MIP-2), and stromal cell-derived factor-1 (SDF-1). 14 In addition, after busulfan-induced depletion of SSCs in mice, the transplantation of TECs has been proven to restore spermatogenesis.…”

“… 14 Furthermore, TECs can serve as an effective feeder layer to enhance the proliferation and self-renewal ability of rat SSCs in vitro while maintaining the characteristics of stem cells. 13 …”

Mitofusins: from mitochondria to fertility

“…SSCs are the basis of spermatogenesis and are located at the base of the varicocele [ 94 ]. After division of the SSCs, some of the daughter cells form new SSCs, and then complete their self-renewal [ 95 ].…”