Exploring the cyclooxygenase 2 (COX2)/15d-Δ12,14PGJ2 system in hamster Sertoli cells: Regulation by FSH/testosterone and relevance to glucose uptake

We have previously described a stimulatory effect of testosterone on cyclooxygenase 2 (COX2) expression and prostaglandin (PG) synthesis, and the involvement of PGs in the modulation of testosterone production in Leydig cells of the seasonal breeder Syrian hamster. In this study, we investigated the existence of a COX2/PGs system in hamster Sertoli cells, its regulation by testosterone and FSH, and its effect on glucose uptake. COX2 expression was observed in Sertoli cells of both reproductively active and inactive adult hamsters. Testosterone and the plasma membrane-impermeable testosterone-BSA significantly induced COX2 expression, mitogen activated protein kinases 1/2 (MAPK1/2) phosphorylation and 15d-Δ12,14PGJ2 production in Sertoli cells purified from photoperiodically regressed hamsters. These actions were abolished by the antiandrogen bicalutamide and by the inhibitor of MAPK kinase (MEK1/2) U0126, suggesting that testosterone exerts its stimulatory effect on COX2/PGs through a non-classical mechanism that involves the presence of androgen receptors and MAPK1/2 activation. FSH also stimulated COX2/PGs via MAPK1/2 phosphorylation.FSH and testosterone stimulate, whereas 15d-Δ12,14PGJ2 via PPARγ inhibits, [2,6-3H]-2-deoxy-d-glucose ([3H]-2-DOG) uptake. Meloxicam, a selective COX2 inhibitor, further increases [3H]-2-DOG uptake in the presence of FSH or testosterone. Thus, in addition to their positive effect, FSH and testosterone may also exert an indirect negative regulation on glucose uptake which involves the COX2/15d-Δ12,14PGJ2/PPARγ system.Overall, these results demonstrate the presence of a COX2/PG system in hamster Sertoli cells which might act as a local modulator of FSH and testosterone actions.

Highlights► A COX2/15d-Δ12,14PGJ2 system is present in hamster Sertoli cells (SC). ► Testosterone (T) and FSH up-regulate COX2/15d-Δ12,14PGJ2 via MAPK1/2 activation. ► A membrane androgen receptor is proposed to partake in T action on COX2/15d-Δ12,14PGJ2. ► T and FSH stimulate glucose uptake by SC, whereas 15d-Δ12,14PGJ2 inhibits it. ► The COX2/15d-Δ12,14PGJ2 system is a local modulator of T and FSH actions on SC.