BACKGROUND Recent studies suggest a role for luteinizing hormone and human chorionic gonadotrophin receptor (LH/hCGR) signalling in the regulation of the oocyte-cumulus oophorus cell interplay. The present study aimed at assessing the LH/hCGR gene expression in cumulus cells (CCs) surrounding oocytes in patients undergoing controlled ovarian hyperstimulation (COS) before ICSI and to relate the ...

Thyroid hormones have diverse effects on ovarian function. We examined the expression of thyroid hormone receptor (TR) mRNAs (including TRalpha-1, TRbeta-1, TRbeta-2, and c-erbAalpha-2 isoforms) in three types of cells from human follicles, and determined the concentration of free tri-iodothyronine (T3) present in human follicular fluid. Human failed-fertilized oocytes, granulosa (GC) and cumul...

Background: Cryopreservation of oocytes, which is an interesting procedure to conserve female gametes, is an essential part of reproductive biotechnology. The objective of the present study was to investigate the effects of cumulus cells on survival,in vitro maturation,fertilization and subsequent developmental capacity of mouse germinal vesicle stage oocytes during vitrification. Materials and...

Besides the established selection criteria based on embryo morphology and blastomere number, new parameters for embryo viability are needed to improve the clinical outcome of IVF and more particular of elective single-embryo transfer. Genome-wide gene expression in cumulus cells was studied, since these cells surround the oocyte inside the follicle and therefore possibly reflect oocyte developm...

It is widely held that mammalian cumulus cell (CC) expansion requires oocyte-paracrine signalling, however in three of the four species studied to date, CC expansion occurs in the absence of the oocyte. This study was conducted to examine the paracrine and SMAD/MAPK intracellular signalling mechanism mediating porcine CC expansion, and to compare these to the mouse. Cumulus-oocyte complexes (CO...

The adenosine monophosphate-activated protein kinase (AMPK) activators, 5'-aminoimidazole-4-carboxamide 1-β-D-ribofuranoside (AICAR) and metformin (MET), inhibit resumption of meiosis in bovine cumulus-enclosed oocytes (CEO) and denuded oocytes (DO). The objectives of this study were to: (1) examine the effects of AMPK inhibitors on bovine oocyte meiosis in vitro; and (2) determine if AICAR or ...

The CC (cumulus cell) proliferation index in relation to the expression and distribution of Cdk4 and Cx43 proteins, which are crucial factors for oocyte maturation, was investigated. Cumulus-oocyte complexes (COCs) were recovered from pubertal crossbred Landrace gilts and treated with collagenase, and separated CCs were cultured in standard TCM199 medium for 44 h. At each step of in vitro culti...

Cumulus cell (CC) apoptosis is inversely correlated with embryonic development in vitro. Therefore, inhibition of CC apoptosis is important for proper embryonic development and quality. Retinoic acids (all-transRA and 9-cisRA) are natural components of retinoids, and 9-cisRA is the physiologically active metabolite of retinoic acid in vitro. During in vitro maturation, 9-cisRA enhances oocyte c...

background: the mitogen-activated protein kinase (mapk) pathway is one of the major signaling pathways that transmit intracellular signals initiated by extracellular stimuli to the nucleus. the stress-activated protein kinase (sapk)/c-jun nh2-terminal kinase is a subfamily of map kinases implicated in cytokine and stress responses. objective: in this study, we have examined total and phosphoryl...