Glycated fibroblast growth factor-2 is quickly produced in vitro upon low-millimolar glucose treatment and detected in vivo in diabetic mice.
Angiogenesis impairment in hyperglycemic patients represents a leading cause of severe vascular complications of both type-1 and -2 diabetes mellitus (DM). Angiogenesis dysfunction in DM is related to glycemic control; however, molecular mechanisms involved are still unclear. Fibroblast growth factor-2 (FGF-2) is a potent angiogenic factor and, according to previous evidence, may represent a key target of molecular modifications triggered by high-sugar exposure. Therefore, the purpose of this study was to investigate whether short incubation with hyperglycemic levels of glucose affected FGF-2 and whether glucose-modified FGF-2 was detectable in vivo. Biochemical analyses carried out with SDS-PAGE, fluorescence emission, mass-spectrometry, immunoblot, and competitive ELISA experiments demonstrated that human FGF-2 undergoes a rapid and specific glycation upon 12.5-50 mm glucose exposure. In addition, FGF-2 exposed for 30 min to 12.5 mm glucose lost mitogenic and chemotactic activity in a time- and dose-dependent manner. Under similar conditions, binding affinity to FGF receptor 1 was dramatically reduced by 20-fold, as well as FGF receptor 1 and ERK-1/2 phosphorylation, and FGF-2 lost about 45% of angiogenic activity in two different in vivo angiogenic (Matrigel and chorioallantoic-membrane) assays. Such glucose-induced modification was specific, because other angiogenic growth factors, namely platelet-derived growth factor BB and placental-derived growth factor were not significantly or markedly less modified. Finally, for the first time, glycated-FGF-2 was detected in vivo, in tissues from hyperglycemic nonobese diabetic mice, in significantly higher amounts than in normoglycemic mice. In conclusion, hyperglycemic levels of glucose may strongly affect FGF-2 structure and impair its angiogenic features, and endogenous glycated-FGF-2 is present in diabetic mice, indicating a novel pathogenetic mechanism underlying angiogenesis defects in DM.
Facchiano
Francesco
F
Dipartimento di Ematologia, Oncologia e Medicina Molecolare, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Roma, Italy. facchian@iss.it
D'Arcangelo
Daniela
D
Russo
Katia
K
Fogliano
Vincenzo
V
Mennella
Carmela
C
Ragone
Raffaele
R
Zambruno
Giovanna
G
Carbone
Virginia
V
Ribatti
Domenico
D
Peschle
Cesare
C
Capogrossi
Maurizio C
MC
Facchiano
Antonio
A
D000818:Animals; D001667:Binding, Competitive; D001786:Blood Glucose / Q000502:physiology; D002417:Cattle; D002478:Cells, Cultured; D018925:Chemokines / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000097:blood*; D004305:Dose-Response Relationship, Drug; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism*; D005947:Glucose / Q000493:pharmacokinetics*; D017127:Glycation End Products, Advanced / Q000096:biosynthesis* / Q000097:blood; D006031:Glycosylation; D006133:Growth Substances / Q000378:metabolism; D006801:Humans; D006943:Hyperglycemia / Q000097:blood / Q000139:chemically induced; D051379:Mice; D016688:Mice, Inbred NOD; D018919:Neovascularization, Physiologic; D051496:Receptor, Fibroblast Growth Factor, Type 1 / Q000378:metabolism
D001786:Blood Glucose; D018925:Chemokines; D017127:Glycation End Products, Advanced; D006133:Growth Substances; D016222:Fibroblast Growth Factor 2; C496349:Fgfr1 protein, mouse; D051496:Receptor, Fibroblast Growth Factor, Type 1; D005947:Glucose