BDNF-induced expansion of cumulus-oocyte complexes in pigs was mediated by microRNA-205

The neurotrophin family of proteins is required for the survival and differentiation of the nervous system and is important to the development of reproductive tissues. The objectives of the present study were to detect the presence of the brain-derived neurotrophic factor (BDNF) and its tyrosine kinase receptor protein in cumulus-oocyte complexes in pigs and to explore the role of microRNAs in the BDNF-induced in vitro maturation of oocytes. We demonstrate that both BDNF and tyrosine kinase receptor protein are expressed in porcine cumulus oocyte complexes. BDNF supplementation promotes the in vitro maturation of porcine oocytes. MiRNA-205 is downregulated during the BDNF-induced maturation of oocytes. The overexpression of miRNA-205 in granulosa cells and reporter gene assay shows that the marker gene ptx3 for cumulus expansion is the putative target gene of miR-205. Our data provide evidence that the BDNF-induced maturation of oocytes in pigs may be mediated by miR-205 through the regulation of potential target gene, ptx3.