Figure 5.

Establishing a link between hCG/LHCGR signaling and ESR2 activation that induces Kiss1 expression in rat granulosa cells. Four-week-old wild-type female rats were injected with 30 IU PMSG, and 48 h after PMSG administration, 30 IU of hCG was injected intraperitoneally. Granulosa cells were isolated 48 h after PMSG treatment or 4 h after hCG treatment in PMSG-primed rats. (A, D, G, and J) Total RNAs purified from granulosa cells were used for RT-qPCR analyses, and (B, E, H and K) protein extracts were subjected to Western blot analyses. Western blot data from three different Western blots performed on six independent samples were quantified by (C, F, I and L) ImageJ analyses. (A, B) Esr2 mRNA and protein levels in wild-type rat granulosa cells 48 h after PMSG injection did not show any significant difference from that of 4 h after hCG injection in PMSG-primed rats. (B, C) However, pESR2 (S105) protein levels were significantly higher 4 h after hCG injection. (D, E) Erk2 mRNA and protein levels in wild-type rat granulosa cells 48 h after PMSG injection were also not different from those of 4 h after hCG injection in PMSG-primed rats. (E, F) However, pERK2 (T185/Y187) protein levels were significantly higher after hCG injection. In contrast, expression of Fosl2 and JunB was markedly upregulated in granulosa cells after hCG injection at both (G, J) mRNA and (H, I, K, L) protein levels. RT-qPCR and Western blot signal quantification data are presented as mean ± SEM. n = 6. *P ≤ 0.05.