The highly conserved polo-like kinases (Plks) are potent regulators of multiple functions in the cell cycle before and during mitotic cell division. We investigated the expression pattern of Plk genes and their potential role(s) in the rat ovary during the periovulatory period. Plk2 and Plk3 were highly induced both in intact ovaries and granulosa cells in vivo after treatment with the luteiniz...

Granulosa cells support the developing oocytes and serve as transducers of the ovulatory stimulus induced by LH surge. Fyn kinase is expressed in granulosa cells, though its role in these cells has not been studied. In human embryonic kidney 293T cells, microRNA (miR)-125a-3p down-regulates Fyn expression, causing a decrease in cells' migratory ability. Our aim was to explore the role of miR-12...

We have examined estrogen-responsiveness of ovarian granulosa cells by focusing on estrogen receptor (ER) expression. Estrogen responsiveness was determined by examining the effect of 17beta-estradiol (1-10 nM) on luciferase reporter activity in rat granulosa cells transfected with an ERE-luciferase construct. The results demonstrate an estrogen-induced (approximately 3-fold) increase in lucife...

Intraovarian hyperandrogenism is one of the determining factors of follicular arrest in women with polycystic ovary syndrome (PCOS). Using androgenized rat models, we investigated the effects of androgens on metabolism, as well as on factors involved in follicular arrest and the reduced number of estrus cycles. The dihydrotestosterone (DHT)-treated rats had fewer estrus cycles, higher numbers o...

The developing ovarian follicle is one of the most rapidly proliferating normal tissues in vivo. Mesenchymal-epithelial cell interactions between theca cells and granulosa cells are essential for this follicular expansion. Ovarian hormones (i.e. estrogen and LH) may promote follicular development by regulating the local production of mesenchymal inducer proteins that mediate theca cell-granulos...

Ovarian hormones (i.e., estrogen and LH) may promote folliculogenesis by regulating the local production of mesenchymal "inducer proteins" that mediate theca cell-granulosa cell interactions. Theca cells produce hepatocyte growth factor (HGF) that can stimulate granulosa cell growth. In order to investigate the physiological role of HGF in the ovarian follicle, the developmental and hormonal re...

Follicular development is associated with both proliferation and differentiation of granulosa cells under the control of FSH. We show that regulation of genes involved in cellular proliferation by FSH can be functionally separated from the regulation of genes involved in granulosa cell differentiation by synergistic actions of activin and T. Incubation of undifferentiated rat granulosa cells wi...

The granulosa cell tumor is the most common malignant functioning tumor of the ovary. When functional, granulosa tumor almost always are estrogenic although rare tumors are androgenic. Progesterone producing by these tumors has only been reported twice. We report a case of granulosa cell tumor in a 7 years old girl with precocious puberty who represent the first case of progesterone producing b...