The role of brain-derived neurotrophic factor in mouse oocyte maturation in vitro involves activation of protein kinase B

Brain-derived neurotrophic factor (BDNF) can pi ornate developmental competence in mammalian oocytes during in vitro maturation, but the signal transduction pathways are not clear In this study, we investigated (using western blots) the effects of BDNF on the phosphorylation of protein kinase B (PKB) and mitogen-activated protein kinase (MAPK) in mouse oocytes and cumulus cells cultured in vitro Treatment with BDNF enhanced phosphorylation of PKB in oocytes at 2 h (P = 0 0006) and 3 h (P < 0 0001) of in vitro maturation. computed with control oocytes However, the pan-specific tyrosine kinase (Trk) inhibitor K252a together with BDNF completely inhibited phosphorylation of PKB in the oocytes Furthermore. BDNF increased phosphorylation of MAPK in oocytes at 16 h of in vino maturation (P = 0 0041), but K252a together with BDNF did not reduce phosphorylation of MAPK in the oocytes For cumulus cells. BDNF significantly prolonged the phosphorylation of PKB and MAPK and increased the total amounts of PKB and MAPK proteins after 16 h of in vitro maturation However. BDNF did not affect apoptosis of the cumulus cells during oocyte maturation in vitro In conclusion, the PKB pathway is likely to be one signaling cascade activated by BDNF in combination with the TrkB receptor, whereas the MAPK pathway is not involved These findings may have relevance for BDNF-induced promotion of developmental capacity of fit vitro-matured oocytes (C) 2010 Elsevier Inc. All rights reserved.