Changes in the gene expression of adiponectin and adiponectin receptors (AdipoR1 and AdipoR2) in ovarian follicular cells of dairy cow at different stages of development.

Adiponectin is one of the most important, recently discovered adipocytokines that acts at various levels to control male and female fertility through central effects on the hypothalamus-pituitary axis or through peripheral effects on the ovary, uterus, and embryo. We studied simultaneous changes in the gene expression pattern of adiponectin and adiponectin receptors 1 and 2 (AdipoR1 and AdipoR2) in granulosa and theca cells, cumulus-oocyte complex, and in corpus luteum in healthy bovine (Bos tarus) follicles at different stages of development. The expression levels of adiponectin, AdipoR1, and AdipoR2 mRNA were lower (P<0.05) in granulosa and cumulus cells in comparison with that in theca cells and oocyte. In contrast with the oocyte, AdipoR1 in granulosa, theca, and luteal cells was expressed (P<0.05) more than AdipoR2. Adiponectin expression increased (P<0.05) in granulosa cells and in cumulus-oocyte complex during follicular development from small to large follicles. Opposite results were observed in theca cells. Expression of adiponectin was highest in the late stages of corpus luteum (CL) regression, whereas lower expression was recorded in active CL (P<0.05). AdipoR1 and AdipoR2 expression increased during the terminal follicular growth in granulosa and theca cells (P<0.05) and during the luteal phase progress in CL. There was positive correlation between adiponectin mRNA level in granulosa cells from large follicles and follicular fluid estradiol concentration (r=0.48, P<0.05) and negative correlation between adiponectin mRNA abundance in theca cells and follicular fluid progesterone concentration (r=-0.44, P<0.05). In conclusion, we found that the physiologic status of the ovary has significant effects on the natural expression patterns of adiponectin and its receptors in follicular and luteal cells of bovine ovary.