FIGURE 9.

GnRH acting via the PKC but not the PKA pathway synergistically increases the Dex-mediated up-regulation of the SGK-1 gene. A, LβT2 cells were incubated for 8 h in serum-free medium with 100 nm Dex, 100 nm GnRH, a combination of Dex plus GnRH, 2 mm 8-bromo-cAMP, and a combination of Dex plus 8-bromo-cAMP. Total RNA was isolated and reverse-transcribed, and relative levels of SGK-1 transcripts were determined by quantitative real-time PCR. Fold changes in SGK-1 mRNA levels were normalized to GAPDH transcripts and were calculated relative to vehicle-treated (control (Ctrl)) samples. The graph is representative of three independent experiments. B, as in A, except that 8-bromo-cAMP was replaced with 20 ng/ml PMA. C, as in B, except the cells were stimulated in the presence and absence of 100 nm PKC inhibitor. One-way ANOVA with Dunnett's post-test was used for statistical analysis and is denoted as *, **, or *** to indicate p < 0.05, p < 0.01, or p < 0.001, respectively.