Endocrine Abstracts

Defects in any of the four functional domains of the androgen receptor (AR) (resulting from loss-of-function or gain-of-function mutations), may affect androgen action. Specific AR splice variants have been reported in women with PCOS (Wang et al, PNAS 2015 112 4743). In this study we sought to identify AR splice variants in granulosa-lutein (GL) cells of women with and without PCOS and to assess their functional significance. GL cells were harvested from women undergoing IVF (6 with PCOS, 9 controls). AR gene expression by qPCR was performed, using primers directed against full-length AR (AR-fl) and well-recognised AR variants (AR-567es, AR-v7, AR-exon1) as well as those that appear to be exclusively expressed in PCOS GL cells – with an insertion (AR-ins) or deletion (AR-del) between exons 2 and 3. AR-fl expression was greater in women with PCOS than those without. AR-v7 was undetectable in all samples. Variants AR-del, AR-567es and AR-exon1 were expressed in GL cells but showed no differences between controls and PCOS. There was, however, a 3-fold increase (P<0.05) in expression of AR-ins in cells from women with PCOS compared with controls. AR-flor or AR-ins was transfected into HEK293 cells and exposed to dihydrotestosterone (DHT) in culture. Using immunohistochemistry, we observed that AR-fl was, as expected, translocated to the nucleus upon DHT treatment; by contrast AR-ins remained cytoplasmic. Preliminary studies of non-genomic AR signalling in HEK293 cells show that both AR-fl and AR-ins respond within 30 mins to DHT exposure, by activation of both PI3K and MAPK pathways. In summary, AR splice variants were detected in GL cells of women with and without PCOS, with greater expression of AR-ins found in cells from PCOS. We suggest that non-genomic signalling of AR-fl and AR-ins observed in HEK293 cells results in aberrant function in PCOS GL cells, in which both AR-fl and AR-ins are overexpressed.