Effects of interferon on the steroidogenic functions and proliferation of immature porcine granulosa cells in culture

Abstract

Recent studies suggest the relevance of several cytokines to the growth and differentiation of granulosa cells. In the present study, we investigated the effects of interferon (IFN) on the steroidogenic functions and proliferation of immature porcine granulosa cells. Human IFN-α inhibited FSH-induced progesterone secretion in a concentration-dependent manner. The effect of IFN-α was significant at a concentration as low as 10 pg/ml. Maximal inhibitory concentrations (10-50 ng/ml) of IFN-α reduced FSH-induced progesterone secretion by 70%. In contrast, estradiol secretion induced by FSH was significantly enhanced by relatively high concentrations (1-50 ng/ml) of IFN-α. IFN-α (0.1-10 ng/ml) reduced cAMP generation in response to FSH by as much as 80%, although its effect was not concentration-dependent. The proliferation of cultured granulosa cells was inhibited by IFN-α in a concentration-dependent manner. Human IFN-γ did not affect granulosa cell functions. The stimulation of estradiol secretion and the inhibition of cell proliferation induced by IFN-α in cultured porcine granulosa cells in this study are in contrast with the effects of IL-1, which, as we reported previously, inhibited both progesterone and estradiol secretion and stimulated cell growth in these cell cultures. Such differences in the mode of action of cytokines may contribute to the regulation of granulosa cell functions under physiological or pathological conditions.