ABSTRACT
Frizzled 3 is an important receptor in the Wnt/ß-catenin pathway, a conserved signaling pathway that regulates gene expression and controls diverse developmental processes. However, the role of this protein during follicular development in the adult ovary is not known. The present study was designed to investigate the expression and localization of Frizzled 3 mRNA and protein during the estrous cycle in the mouse ovary through in situ hybridization (ISH), real-time quantitative polymerase chain reaction, immunohistochemistry and western blot. ISH results showed that in proestrus, high expression of Frizzled 3 was found in the granulosa and stroma with weak levels in the corpus luteum. In estrus and diestrus, the stroma had high Frizzled 3 expression, but levels were low in granulosa cells and corpus luteum. In the metestrus, moderate expression of Frizzled 3 was found in the stroma but low to no expression was found in luteal cells and follicles. The mRNA and protein levels of Frizzled 3 were found to be the highest in proestrus and diestrus compared to estrus and metestrus (P < 0.05), confirming the ISH results. During estrus and diestrus, high Frizzled 3 expression was observed in the stroma and moderate levels in granulosa cells, and during estrus and proestrus, low expression was seen in the oocyte cell membrane. The western blot results further confirmed this change during the estrous cycle. Together, these results indicate that Frizzled 3 is involved in regulating follicular development and oocyte maturation during the estrous cycle.
Subject(s)
Corpus Luteum/metabolism , Frizzled Receptors/genetics , Gene Expression Regulation, Developmental , Oocytes/metabolism , Ovarian Follicle/metabolism , Animals , Corpus Luteum/growth & development , Corpus Luteum/ultrastructure , Diestrus/genetics , Estrus/genetics , Female , Frizzled Receptors/metabolism , In Situ Hybridization , Mice , Mice, Inbred ICR , Oocytes/growth & development , Oocytes/ultrastructure , Ovarian Follicle/growth & development , Ovarian Follicle/ultrastructure , Proestrus/genetics , Real-Time Polymerase Chain Reaction , Time FactorsABSTRACT
Bone morphogenetic proteins (BMPs) are the key factors in maintaining cell growth and differentiation in ovaries. BMPs initiate signaling by assembling BMP receptors and activating Smads, which in turn alter the expression of target genes. However, little is known about the effect of the deletion of the Bone morphogenetic protein receptor type IB (BMPRIB) on porcine granulosa cell (GCs). The objective of this study was to determine the effects of BMPRIB gene silencing, by small interfering RNA (siRNA), on the apoptosis and steroidogenesis of porcine GCs, and the expression of cell cycle-related and apoptosis-related genes. Results indicate that the BMPRIB siRNA caused specific inhibition of BMPRIB mRNA expression after transfection. Knockdown of the BMPRIB gene significantly inhibited porcine GCs proliferation and estradiol production, while inducing apoptosis of porcine GCs. Additionally, the declined expression of the BMPRIB gene changed the expressions of CylinD2, Cdk2, Bcl-2, and Cyp19a1. These findings provide an important role of BMPRIB in the regulation of apoptosis and steroidogenesis of porcine GCs.