Influence of FSH on Granulosa Cell XIAP Expression and Apoptosis In Vitro
To test if the FSH-induced follicular growth and increase in cell number in vitro is caused by a direct action of gonadotropin on granulosa cells to stimulate proliferation and/ or suppress apoptosis, granulosa cells were cultured for 48 h in the absence or presence of FSH (100 ng/ml). Analysis of variance indicates that although FSH significantly decreased granulosa cell apoptosis compared to control (P < 0.01), total granulosa cell number was markedly lower in the presence of gonadotropin (P < 0.02, two-way ANOVA) (Table 1), irrespective of up- or down-regulation of XIAP (P < 0.05, Tukey test). Propecia from Canadian pharmacies
To determine if FSH has a direct regulatory role in granulosa cell XIAP expression, the influence of gonadotropin (0-150 ng/ml) on XIAP contents in cultured granulosa cells was assessed during 24- and 48-h culture periods. The FSH significantly increased granulosa cell XIAP content in a concentration-dependent manner (Fig. 9). Arcsine square root-transformed two-way ANOVA indicates a significant effect of concentration (P < 0.01) but not of time (P > 0.05). To assess if XIAP may play an important role in the regulation of granulosa cell fate, the XlAP level was manipulated by adenoviral expression of XIAP sense and antisense (MOl = 5 and 20, respectively) in the absence and presence of FSH (100 ng/ml). Overexpression of XIAP alone (i.e., in the absence of FSH) markedly suppressed granulosa cell apoptosis (P < 0.05) (Table 1). In addition, adenoviral XIAP sense cDNA delivery potentiated the an-tiapoptotic action of FSH compared with LacZ infection (P < 0.05) (Table 1). In the absence of FSH, XIAP antisense expression increased follicular apoptosis compared to LacZ control (P < 0.05) (Table 1). Moreover, in the presence of gonadotropin, adenoviral XIAP antisense infection markedly attenuated the cell survival effect of FSH and increased the number of apoptotic granulosa cells (P < 0.05).