Protein kinases influence bovine oocyte competence during short-term treatment with recombinant human follicle stimulating hormone.
The aim of this study was to investigate the effect of short-term treatment (first 2 or 6 h) with recombinant human follicle-stimulating hormone (r-hFSH) during in vitro maturation (IVM) on the developmental competence of bovine oocytes. The roles of protein kinase A (PKA) and protein kinase C (PKC) (possibly involved in FSH response), were investigated using activators (Sp-cAMPS, PMA) or inhibitors (Rp-cAMPS, sphingosine) of these two protein kinases, respectively. The developmental competence of bovine oocytes was measured by the rate of blastocyst formation after in vitro fertilization (IVF). Our results showed that when cumulus-oocyte complexes (COCs) were cultured with r-hFSH for the first 6 h, a highly significant (P < 0.0001) improvement is seen in blastocyst development rate as a proportion of oocytes in culture compared with those matured with r-hFSH for the first 2 or 24 h. A transient exposure (6 h) to the highest dose (100 microM) of forskolin (an activator of adenylate cyclase) increased (P < 0.05) the rate of blastocyst formation. But the PKA inhibitors (Rp-cAMPS) did not affect the stimulatory effects of r-hFSH on the blastocyst yield. However, stimulation of PKC by low doses of PMA (0.1-0.5 microM) during short-term treatment, enhanced (P < 0.0001) the developmental capacity of oocytes, while sphingosine (a specific inhibitor of PKC) inhibited (P < 0.05) the stimulatory effects of r-hFSH on the rate of blastocyst formation. Our results indicate that although the developmental capacity of bovine oocytes in vitro can be modulated by both the PKA, and the PKC pathways, the activation of PKC during short-term treatment can mimic the effect of r-hFSH on the cytoplasmic maturation in bovine oocytes in vitro.
Ali
Atef
A
Centre de Recherche en Biologie de la Reproduction (CRBR), Department of Animal Science, Laval University, Ste-Foy, Quebec, Canada, G1K 7P4.
Sirard
Marc-André
MA
D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D002417:Cattle; D002470:Cell Survival; D002478:Cells, Cultured; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000031:analogs & derivatives / Q000494:pharmacology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D020536:Enzyme Activators / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005307:Fertilization in Vitro; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D006801:Humans; D009865:Oocytes / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D009866:Oogenesis / Q000187:drug effects*; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism; D011494:Protein Kinases / Q000378:metabolism*; D011994:Recombinant Proteins / Q000494:pharmacology; D013110:Sphingosine / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013873:Thionucleotides / Q000494:pharmacology; D013997:Time Factors
D020536:Enzyme Activators; D004791:Enzyme Inhibitors; D011994:Recombinant Proteins; D013873:Thionucleotides; D005576:Colforsin; C016957:adenosine-3',5'-cyclic phosphorothioate; D005640:Follicle Stimulating Hormone; D000242:Cyclic AMP; D011494:Protein Kinases; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C; D000262:Adenylyl Cyclases; D013110:Sphingosine; D013755:Tetradecanoylphorbol Acetate