title: Effects of HIF prolyl-hydroxylase-2 gene silencing on HCG-induced vascular endothelial growth factor expression in luteal cells.
abstract: Vascular endothelial growth factor (VEGF)-dependent angiogenesis plays a crucial role in corpus luteum formation and its functional maintenance in mammalian ovaries. We recently reported that activation of hypoxia-inducible factor (HIF)-1α signaling contributes to the regulation of VEGF expression in luteal cells (LCs) in response to human chorionic gonadotropin (HCG). We examined whether HIF prolyl-hydroxylase (PHD)-2 gene silencing induces VEGF expression in LCs and enhanced its expression induced by HCG in LCs. Using real-time polymerase chain reaction and western blot analysis, we measured the expression of PHD-2 to confirm plasmid PHD-2 shRNA transfection and protein expression and investigated the changes in HIF-1a and VEGF expression after treatment with HCG and PHD-2 shRNA transfection. After PHD-2 shRNA transfection, PHD-2 expression was significantly lower than that in control groups with or without HCG treatment, while a significant increase in VEGF mRNA was observed compared to in controls, indicating that PHD-2 plays an important role in VEGF regulation. Additionally, changes in VEGF mRNA expression were consistent with the expression levels of HIF-1a protein, not HIF- 1a mRNA, which is regulated by HIF prolyl-hydroxylase-mediated degradation. Our results indicate that PHD-2 gene silencing can induce VEGF expression in LCs and HCG-induced VEGF expression can be further enhanced by PHD-2 gene silencing through an HIF-1a-mediated mechanism in LCs. This PHD-2-mediated transcriptional activation may be important for regulating VEGF expression through HIF-1a signaling in LCs during corpus luteum development in mammals.
authors.affiliation: Provincial Key Laboratory for Developmental Biology and Neurobiology, College of Life Science, Fujian Normal University, Fuzhou, China.|Laboratory of Animal Reproduction, Department of Animal Science, College of Animal Science and Technology.
authors.forename: Z H
authors.initials: ZH
authors.lastname: Zhang
authors.affiliation: Laboratory of Animal Reproduction, Department of Animal Science, College of Animal Science and Technology.
authors.forename: D Z
authors.initials: DZ
authors.lastname: Yin
authors.affiliation: Laboratory of Animal Reproduction, Department of Animal Science, College of Animal Science and Technology.
authors.forename: X S
authors.initials: XS
authors.lastname: Pang
authors.affiliation: Provincial Key Laboratory for Developmental Biology and Neurobiology, College of Life Science, Fujian Normal University, Fuzhou, China.
authors.forename: Z C
authors.initials: ZC
authors.lastname: Wang
mesh_terms: D000818:Animals; D006063:Chorionic Gonadotropin / Q000494:pharmacology*; D005260:Female; D015870:Gene Expression; D005786:Gene Expression Regulation / Q000187:drug effects*; D020868:Gene Silencing; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics / Q000378:metabolism; D064799:Hypoxia-Inducible Factor-Proline Dioxygenases / Q000235:genetics*; D008184:Luteal Cells / Q000187:drug effects* / Q000378:metabolism*; D010957:Plasmids / Q000235:genetics; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D051381:Rats; D014162:Transfection; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics*
chemical_list: D006063:Chorionic Gonadotropin; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D042461:Vascular Endothelial Growth Factor A; D064799:Hypoxia-Inducible Factor-Proline Dioxygenases