抄録
Background: Recently we have identified that FSH can modulate and reset the circadian rhythms in mature granulosa cells (GCs). With the maturation process initiated by FSH, GCs seem to acquire functional circadian clock. Gap junction plays an important role in the regulation of ovarian folliculogenesis. In GCs, gap junctions consist mainly of CX43. Recent reports proved that FSH can increase Cx43 mRNA level. In this study, the relationship between gap junction and maturation of clock system in GCs stimulated by FSH was dissected. Methods: Immature Per2-dLuc transgenic rats were injected with DES or eCG to prepare immature and mature GCs respectively. Per2 oscillations were measured by real-time monitoring system. Gene expression levels were examined by qPCR. Results: FSH treatment significantly increased the amplitude of Per2 oscillations in GCs. Per2 and Rev-erbα mRNA levels confirmed this result. FSH also induced a great phase advance shift of Per2 oscillations. Mature GCs cultured with FSH for 2 d expressed significant higher mRNA level of Per2, Rev-erbα, Bmal1, Lhr, and Cx43 than immature GCs cultured with 5% FBS for 2 d. Conversely, the mRNA expression of Clock and GR was not changed. Two gap junction blockers, Lindane and Carbenoxolone, significantly decreased the amplitude of Per2 oscillations, which further proved by Per2 and Rev-erbα transcript levels. In addition, both of them induced an obvious phase delay shift of Per2 oscillations. The current results suggest that FSH regulates and induces maturation of clock system through the increasing expression of CX43
