Endocrine Abstracts

Spermatogenesis is a complex process that requires the formation of junctional complexes between somatic Sertoli cells and germ cells and hormonal regulation of the Sertoli cells. Androgens and oestrogens are both synthesised in the testis. In adults Sertoli cells contain both androgen receptor (AR) and oestrogen receptor beta (ERß). In the present study we used a transformed Sc cell line (SK11) that was prepared from the testes of mice expressing the large T antigen. When grown at 34 °C the cells are mitotically active but when transferred to 39 °C they stop dividing.

SK11 cells expressed mRNAs for AR and ERß as well as for other proteins found in Sc in vivo (ß-tubulin, ß-actin, aromatase, sulphated proteins 1 and 2). Transfer of cells from 34 °C to 39 °C resulted in a decrease in expression of proliferating cell nuclear antigen (PCNA) and an increase in expression of SGP-2 as well as a change in cell shape and re-organisation of the cytoskeleton. These changes parallel those seen in Sc as they undergo functional maturation during the first wave of spermatogenesis. Messenger RNA for the androgen-regulated Sc product Pem was expressed in the SK11 cells and was increased in cells after incubation at 39 °C. Functional activity of AR and ERß was investigated using transient transfections with plasmid reporter constructs containing either 3XERE or pem-ARE-promoters. Expression of the ERE was induced following incubation with E2 or 3ßAdiol consistent with reports that 3ßAdiol (a metabolite of DHT) can activate ERß. Activation of the ERE-reporter did not occur following targeted knockdown of ERß. Up-regulation of the ARE reporter was only induced in the presence of T or DHT but not with E2 or 3ßAdiol.

In conclusion, SK11 cells seem to provide a useful model that can be used to complement studies using Sertoli cell selective gene ablation.