Improvement of in vitro culture of mouse cumulus-oocyte complexes using PDE3-inhibitor followed by meiosis induction with epiregulin.
OBJECTIVE
To explore potential helping effects of a PDE3-inhibitor (PDE3-I), Org9935, in long-term culture of cumulus-corona-oocyte complexes (COC) and to associate adequate stimuli for efficient oocyte maturation.


METHODS
Experimental in vitro study on mice.


METHODS
Academic research laboratory.


METHODS
F1 hybrid mice: C57Bl/6j x CBA/ca.


METHODS
The COCs were selectively retrieved from cultured follicles at the early antral stage and subcultured for 4 days in absence or presence of Org9935 (5 nM to 1 microM).


METHODS
Oocyte nuclear maturation; estradiol and progesterone concentrations in conditioned medium.


RESULTS
Survival of COCs was dose dependently improved by Org9935. When subculture was done in absence of Org9935; human chorionic gonadotropin (hCG), epiregulin, or hCG + epiregulin induced 0%, 17%, and 21%, respectively, of polar body formation. Concentrations above 50 nM prohibited the reinitiation of meiosis by a hCG + epidermal growth factor stimulus. Epiregulin or hCG + epiregulin induced 63% and 66% polar body rate, respectively, but only after washing out the inhibitor. Acute progesterone production occurs after stimulation with hCG, or hCG + epiregulin, but epiregulin alone induces the lowest response.


CONCLUSIONS
Presence of PDE3-I in cultured COCs improves survival. Washout of PDE3-I is necessary for meiotic resumption to occur. Epiregulin by itself induces meiotic maturation but is a weak inducer of progesterone production.
Romero
Sergio
S
Follicle Biology Laboratory, Vrije Universiteit Brussel, Laarbeeklaan 101, 1090 Brussels, Belgium. sromerol@vub.ac.be
Smitz
Johan
J
D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D017077:Culture Media, Conditioned / Q000494:pharmacology; D054885:Cumulus Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D066260:Epiregulin; D004958:Estradiol / Q000378:metabolism; D005260:Female; D008540:Meiosis / Q000187:drug effects*; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D009865:Oocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D009924:Organ Culture Techniques / Q000379:methods*; D006080:Ovarian Follicle / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D058987:Phosphodiesterase 3 Inhibitors; D011374:Progesterone / Q000378:metabolism; D012102:Reproductive Control Agents / Q000494:pharmacology; D013876:Thiophenes / Q000494:pharmacology*
D006063:Chorionic Gonadotropin; D017077:Culture Media, Conditioned; C587880:EREG protein, human; D066260:Epiregulin; C587881:Ereg protein, mouse; D058987:Phosphodiesterase 3 Inhibitors; D012102:Reproductive Control Agents; D013876:Thiophenes; C097915:Org 9935; D011374:Progesterone; D004958:Estradiol; D004815:Epidermal Growth Factor