Metformin decreases IGF1-induced cell proliferation and protein synthesis through AMP-activated protein kinase in cultured bovine granulosa cells.

Although its mechanism of action is still unclear, metformin is an anti-diabetic drug effective to restore cyclicity and spontaneous ovulation in women with polycystic ovary syndrome. It may also reduce the risk of cancer. We have recently shown that metformin treatment decreases steroidogenesis through AMP-activated kinase (AMPK) in granulosa cells of various species.

Adiponectin increases insulin-like growth factor I-induced progesterone and estradiol secretion in human granulosa cells.

Objective: To identify adiponectin and its receptors (AdipoR1 and AdipoR2) in human granulosa cells (GC) and to study the effects of recombinant human adiponectin on P and E(2) secretion from these cells.

Design: The effects of recombinant human adiponectin on the secretion of P and E(2) by cultured human GCs were investigated.

Setting: Academic institutions.

[Adipose tissue, nutrition and reproduction: what is the link?].

The body mass index, and especially the lean/fat tissue ratio, are determinants of female fertility. In 1996, it was claimed that leptin might be the "missing link" between fat and reproduction. Leptin belongs to the adipokine family, which also contains adiponectin and resistin.

Effects of high levels of glucose on the steroidogenesis and the expression of adiponectin receptors in rat ovarian cells.

Background: Reproductive dysfunction in the diabetic female rat is associated with altered folliculogenesis and steroidogenesis. However, the molecular mechanisms involved in the reduction of steroid production have not been described. Adiponectin is an adipocytokine that has insulin-sensitizing actions including stimulation of glucose uptake in muscle and suppression of glucose production in liver.

[AMPK: a link between metabolism and reproduction?].

5'AMP-activated protein kinase (AMPK) is a serine/threonine kinase that acts as a fuel gauge in regulating energy metabolism. It restores cellular ATP levels by switching on catabolic pathways and switching off anabolic pathways. Some evidence indicates that AMPK could be also implicated in reproductive functions such as granulosa cell steroidogenesis and nuclear oocyte maturation in several species.

Role of the peroxisome proliferator-activated receptors, adenosine monophosphate-activated kinase, and adiponectin in the ovary.

The mechanisms controlling the interaction between energy balance and reproduction are the subject of intensive investigations. The integrated control of these systems is probably a multifaceted phenomenon involving an array of signals governing energy homeostasis, metabolism, and fertility. Two fuel sensors, PPARs, a superfamily of nuclear receptors and the kinase AMPK, integrate energy control and lipid and glucose homeostasis.

Possible role of 5'AMP-activated protein kinase in the metformin-mediated arrest of bovine oocytes at the germinal vesicle stage during in vitro maturation.

The 5'AMP-activated protein kinase (AMPK) activation is involved in the meiotic maturation of oocytes in the ovaries of mice and pigs. However, its effects on the oocyte appear to be species-specific. We investigated the patterns of AMPK and mitogen-activated protein kinases (MAPK3/1) phosphorylation during bovine in vitro maturation (IVM) and the effects of metformin, an AMPK activator, on oocyte maturation in cumulus-oocyte complexes (COCs) and denuded bovine oocytes (DOs).

Regulation of adiponectin and its receptors in rat ovary by human chorionic gonadotrophin treatment and potential involvement of adiponectin in granulosa cell steroidogenesis.

In mammals, adiponectin and its receptors (AdipoR1 and AdipoR2) mRNAs are expressed in various tissues. However, the cellular expression and the role of adiponectin system have never been investigated in rat ovary. Here, we report the presence of adiponectin, AdipoR1 and AdipoR2 in rat ovaries, and we have investigated its role in granulosa cells.

IGF-1 receptor signaling pathways and effects of AMPK activation on IGF-1-induced progesterone secretion in hen granulosa cells.

IGF-1 plays a key role in the proliferation and differentiation of granulosa cells. However, the molecular mechanism of IGF-1 action in avian granulosa cells during follicle maturation is unclear. Here, we first studied IGF-1 receptor (IGF-1R) expression, IGF-1-induced progesterone production and some IGF-1R signaling pathways in granulosa cells from different follicles.

Novel FGFR1 sequence variants in Kallmann syndrome, and genetic evidence that the FGFR1c isoform is required in olfactory bulb and palate morphogenesis.

In a new cohort of 141 unrelated patients affected by Kallmann syndrome we identified FGFR1 sequence variants in 17 patients, all in the heterozygous state. The fifteen novel variants consist of 10 missense (p.N77K, p.

Effects of metformin on bovine granulosa cells steroidogenesis: possible involvement of adenosine 5' monophosphate-activated protein kinase (AMPK).

In mammals, IGFs are important for the proliferation and steroidogenesis of ovarian cells. Metformin is an insulin sensitizer molecule used for the treatment of the infertility of women with polycystic ovary syndrome. It is, however, unclear whether metformin acts on ovarian cells.

Expression of adiponectin and its receptors (AdipoR1 and AdipoR2) in chicken ovary: potential role in ovarian steroidogenesis.

Adiponectin and its receptors (AdipoR1 and AdipoR2) mRNAs are expressed in various chicken tissues including ovary. However, the cellular expression and the role of adiponectin system have never been investigated in chicken ovary. Here, we have shown that the level of adiponectin mRNA is about 10- to 30-fold higher (p<0.