title: Equine luteal function regulation may depend on the interaction between cytokines and vascular endothelial growth factor: an in vitro study.
abstract: We hypothesized that cytokines influence luteal angiogenesis in mares, while angiogenic factors themselves can also regulate luteal secretory capacity. Therefore, the purpose of this study was to evaluate the role of cytokines--tumor necrosis factor alpha (TNF), interferon gamma (IFNG) and Fas ligand (FASL)--on in vitro modulation of angiogenic activity and mRNA level of vascular endothelial growth factor A (VEGF), its receptor VEGFR2, thrombospondin 1 (TSP1), and its receptor CD36 in equine corpus luteum (CL) throughout the luteal phase. After treatment, VEGF protein expression was determined in midluteal phase (mid) CL cells. The role of VEGF on regulation of luteal secretory capacity was assessed by progesterone (P(4)) and prostaglandin E(2) (PGE(2)) production and by mRNA levels for steroidogenic enzymes 3-beta-hydroxysteroid dehydrogenase (3betaHSD) and PGE synthase (PGES). In early CL cells, TNF increased angiogenic activity (bovine aortic endothelial cell viability) and VEGF and VEGFR2 mRNA levels and decreased CD36 (real-time PCR relative quantification). In mid-CL cells, TNF increased VEGF mRNA and protein expression (Western blot analysis) and reduced CD36 mRNA levels, while FASL and TNF+IFNG+FASL decreased VEGF protein expression. In late CL cells, TNF and TNF+IFNG+FASL reduced VEGFR2 mRNA, but TNF+IFNG+FASL increased TSP1 and CD36 mRNA. VEGF treatment increased mRNA levels of 3betaHSD and PGES and secretion of P(4) and PGE(2). In conclusion, these findings suggest a novel auto/paracrine action of cytokines, specifically TNF, on the up-regulation of VEGF for angiogenesis stimulation in equine early CL, while at luteolysis, cytokines down-regulated angiogenesis. Additionally, VEGF stimulated P(4) and PGE(2) production, which may be crucial for CL establishment.
authors.affiliation: CIISA, Faculty of Veterinary Medicine, Technical University of Lisbon, Lisbon, Portugal.
authors.forename: António
authors.initials: A
authors.lastname: Galvão
authors.forename: Sofia
authors.initials: S
authors.lastname: Henriques
authors.forename: Daria
authors.initials: D
authors.lastname: Pestka
authors.forename: Karolina
authors.initials: K
authors.lastname: Lukasik
authors.forename: Dariusz
authors.initials: D
authors.lastname: Skarzynski
authors.forename: Luisa Maria
authors.initials: LM
authors.lastname: Mateus
authors.forename: Graça Maria Leitao
authors.initials: GM
authors.lastname: Ferreira-Dias
mesh_terms: D015096:3-Hydroxysteroid Dehydrogenases / Q000378:metabolism; D000818:Animals; D018955:CD36 Antigens / Q000378:metabolism; D002478:Cells, Cultured; D003338:Corpus Luteum / Q000378:metabolism*; D016207:Cytokines / Q000378:metabolism*; D015232:Dinoprostone / Q000378:metabolism; D005260:Female; D006736:Horses / Q000378:metabolism*; D019746:Intramolecular Oxidoreductases / Q000378:metabolism; D008183:Luteal Phase / Q000378:metabolism*; D018919:Neovascularization, Physiologic; D011374:Progesterone / Q000378:metabolism; D000071876:Prostaglandin-E Synthases; D012333:RNA, Messenger / Q000378:metabolism; D019699:Thrombospondins / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism
chemical_list: D018955:CD36 Antigens; D016207:Cytokines; D012333:RNA, Messenger; D019699:Thrombospondins; D042461:Vascular Endothelial Growth Factor A; D011374:Progesterone; D015096:3-Hydroxysteroid Dehydrogenases; D040301:Vascular Endothelial Growth Factor Receptor-2; D019746:Intramolecular Oxidoreductases; D000071876:Prostaglandin-E Synthases; D015232:Dinoprostone