INVESTIGADORES
CASTILLA LOZANO Maria Del Rocio
congresos y reuniones científicas
Título:
TG1019, an eicosanoid receptor, in steroidogenic cell funtion
Autor/es:
DI CÓNSOLI, HERNÁN; COOK, MARIANA; MELE, PABLO; PODEROSO, CECILIA; CASTILLA, ROCÍO; PODESTÁ, ERNESTO J.; CORNEJO MACIEL, FABIANA
Lugar:
Villa Carlos Paz, Córdoba, Argentina
Reunión:
Congreso; XLIV Annual Meeting of Argentine Society for Biochemistry and Molecular Biology (SAIB); 2008
Institución organizadora:
Argentine Society for Biochemistry and Molecular Biology (SAIB)
Resumen:
Hormonal regulation of steroidogenesis involves arachidonic acid (AA) release and metabolization through 5-lipoxygenase pathway. One of the products of this pathway, 5-hidroperoxyeicosatetraenoic acid (5-HpETE), acts as a modulator of the activity of the steroidogenic acute regulatory (StAR) protein promoter. Besides, the TG1019 is a membrane protein with high affinity and response to 5-HpETE, among other AA derivatives. The aim of our work was to elucidate whether this receptor may be involved in steroidogenesis. MA10 cells (murine Leydig testicular cell line) were used to evaluate the effect of docosahexaenoic acid (DHA), an antagonist of the receptor, on steroid production and StAR promoter activity. While the treatment of MA-10 cells with 8Br-cAMP (0.5 mM) during 5 hs increased the levels of progesterone 20-fold compared to control (p<0.01), simultaneous treatment with DHA (10 ìM) reduced steroid production by 66% (p<0.01). This partial inhibition is due to the fact that AA per se or other of its metabolites would exert TG1019-independent effects. Similarly, StAR promoter activity increased 4-fold by 8Br-cAMP treatment (p<0.01) and DHA decreased this stimulatory effect by 50% (p<0.01). These results lead us to conclude that AA might modulate StAR promoter activity and steroidogenesis partially through 5- HpETE production and activation of a membrane receptor, such as Tg1019.