title: Angiogenesis and diabetes: different responses to pro-angiogenic factors in the chorioallantoic membrane assay.
abstract: Hyperglycemia induces defects in angiogenesis without alteration in the expression of major vascular growth factors in the chicken chorioallantoic membrane (CAM) model. A direct negative effect of hyperglycemia on angiogenesis may participate in failures of "therapeutic angiogenesis" trials. Here, we tested the hypothesis that the response to pro-angiogenic molecules such as angiotensin-converting enzyme (ACE), endothelin-1 (ET-1), and vascular endothelial growth factor-A (VEGF) is altered by hyperglycemia. Transfected (Chinese hamster ovary [CHO] or human embryonic kidney [HEK]) cells overexpressing ACE, ET-1, or VEGF were deposed onto the CAM of hyperglycemic or control embryos. The proangiogenic effect was evaluated 3 d later by angiography and histological analyses. Gene expression in response to these factors was assessed by in situ hybridization. Only VEGF overexpression evoked a proangiogenic response in the CAM from hyperglycemic embryos, upregulating the expression of endogenous VEGF, VEGF-R2, and Tie-2, all of them related to activation of endothelial cells. In conclusion, in a model where hyperglycemia does not alter the major vascular growth factor expression, the negative effect of diabetes on capillary density was overcome only by VEGF overexpression, whereas responses to other vasoactive peptides were practically abolished under hyperglycemic conditions.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale (INSERM) U833, Collège de France, Paris, France.
authors.forename: Giovana S
authors.initials: GS
authors.lastname: Di Marco
authors.forename: Antoine
authors.initials: A
authors.lastname: Alam
authors.forename: Frédéric
authors.initials: F
authors.lastname: Dol
authors.forename: Pierre
authors.initials: P
authors.lastname: Corvol
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Gasc
authors.forename: Etienne
authors.initials: E
authors.lastname: Larger
mesh_terms: D043925:Angiogenesis Inducing Agents / Q000378:metabolism*; D000792:Angiography; D000818:Animals; D016466:CHO Cells; D002460:Cell Line; D002642:Chick Embryo; D002645:Chickens; D049033:Chorioallantoic Membrane / Q000378:metabolism*; D006224:Cricetinae; D003412:Cricetulus; D003920:Diabetes Mellitus / Q000378:metabolism* / Q000473:pathology; D019332:Endothelin-1 / Q000235:genetics / Q000502:physiology; D006801:Humans; D006943:Hyperglycemia / Q000139:chemically induced / Q000503:physiopathology; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D051379:Mice; D018919:Neovascularization, Physiologic; D007703:Peptidyl-Dipeptidase A / Q000235:genetics / Q000502:physiology; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000502:physiology
chemical_list: D043925:Angiogenesis Inducing Agents; D019332:Endothelin-1; D042461:Vascular Endothelial Growth Factor A; D007703:Peptidyl-Dipeptidase A