Effects of Chemically Induced Hypothyroidism in Proliferation and Maturation of Neonatal Mouse Testis Development

The immunoprotective nature of the testes has prompted numerous investigations for supportive roles of Sertoli cells (SCs) during allogeneic or xenogeneic cellular grafts. These potential benefits afforded by SCs could be achieved by obtaining enough number of SCs that have most proliferative activity in primary isolation. To investigate the effects of neonatal hypothyroidism on SC proliferation and maturation, we examined the expression changes of cyclin-dependent kinase inhibitor (p27 KiP1 ), androgen receptor (AR), and testicular transcription factors (WT1 and GATA-4) by immunohistochemistry and western blot analysis in 6-propyl-2-thiouracil (PTU)-induced hypothyroidal mice. The expression of p27 KiP1 was low in rapidly proliferating testicular cells but had increased strongly in non-proliferating periods. Delayed expressions of p27 KiP1 on testicular cells of hypothyroidal mice were consistent with the expression patterns of AR and WT1. Whereas GATA-4 expression was kept a constant in all groups. These results indicate that chemically-induced neonatal hypothyroidism may be a useful approach for improving cellular yields and proliferative activity.