BACKGROUND<\/p>\n
Testicular peritubular cells form an ill-characterized cellular compartment of the human testis, which forms a border with Sertoli cells and spermatogonial stem cells (SSCs). A recently developed culture method has identified parts of the secretory repertoire of human testicular peritubular cells (HTPCs), which includes nerve growth factor. Whether peritubular cells produce glial cell line-derived neurotrophic factor (GDNF) and may thus contribute to the stem cell niche is not known.<\/p>\n
METHODS<\/p>\n
We studied GDNF production in isolated peritubular cells from men with normal spermatogenesis (HTPCs) and impaired spermatogenesis and testicular fibrosis (HTPC-Fs). Human testicular biopsies and peritubular cells in culture were evaluated using immunohistochemistry, laser microdissection (LMD), RT–PCR and measurement of GDNF and cAMP by enzyme-linked immunosorbent assay. We also tested whether GDNF production is regulated by tumour necrosis factor- (TNF-) or tryptase, the products of mast cells or macrophages.<\/p>\n
RESULTS<\/p>\n
Peritubular wall cells are in close proximity to cells expressing the GDNF family co-receptor-1. GDNF mRNA was detected in LMD samples of the peritubular and tubular but not interstitial compartments. HTPCs and HTPC-Fs lack FSH- and LH-receptors but express receptors for TNF- and tryptase. Importantly, peritubular cells express GDNF and constitutively released GDNF into the medium in comparably high amounts. TNF- and tryptase had no effect on the secretion of GDNF by HTPCs or HTPC-Fs.<\/p>\n
CONCLUSIONS<\/p>\n
Peritubular cells in testes of normal and sub-\/infertile men produce GDNF and are likely constitutive contributors of the SSC niche in the human testis.<\/p>\n","protected":false},"excerpt":{"rendered":"
BACKGROUND Testicular peritubular cells form an ill-characterized cellular compartment of the human testis, which forms a border with Sertoli cells and spermatogonial stem cells (SSCs). A recently developed culture method has identified parts of the secretory repertoire of human testicular … Continue reading