Selectively desulfated heparin inhibits fibroblast growth factor-induced mitogenicity and angiogenesis.
Fibroblast growth factors (FGFs) are known to induce formation of new blood vessels, angiogenesis. We show that FGF-induced angiogenesis can be modulated using selectively desulfated heparin. Chinese hamster ovary cells (CHO677) deficient in heparan sulfate biosynthesis were employed to assess the function of heparin/heparan sulfate in FGF receptor-1 (FGFR-1) signal transduction and biological responses. In the presence of FGF-2, FGFR-1 kinase and subsequent mitogen-activated protein kinase Erk2 activities were augmented in a dose-dependent manner, whereas high concentrations of heparin resulted in decreased activity. The length of the heparin oligomer, minimally an 8/10-mer, was critical for the ability to enhance FGFR-1 kinase activity. The N- and 2-O-sulfate groups of heparin were essential for binding to FGF-2, whereas stimulation of FGFR-1 and Erk2 kinases by FGF-2 also required the presence of 6-O-sulfate groups. Sulfation at 2-O- and 6-O-positions was moreover a prerequisite for binding of heparin to a lysine-rich peptide corresponding to amino acids 160-177 in the extracellular domain of FGFR-1. Selectively 6-O-desulfated heparin, which binds to FGF-2 but fails to bind the receptor, decreased FGF-2-induced proliferation of CHO677 cells, presumably by displacing intact heparin. Furthermore, FGF-2-induced angiogenesis in chick embryos was inhibited by 6-O-desulfated heparin. Thus, formation of a ternary complex of FGF-2, heparin, and FGFR-1 appears critical for the activation of FGFR-1 kinase and downstream signal transduction. Preventing complex formation by modified heparin preparations may allow regulation of FGF-2 functions, such as induction of angiogenesis.
Lundin
L
L
Department of Genetics and Pathology, Rudbeck Laboratory, S-751 85 Uppsala, Sweden.
Larsson
H
H
Kreuger
J
J
Kanda
S
S
Lindahl
U
U
Salmivirta
M
M
Claesson-Welsh
L
L
D000482:Allantois / Q000098:blood supply; D000595:Amino Acid Sequence; D000818:Animals; D016466:CHO Cells; D002455:Cell Division / Q000187:drug effects; D002642:Chick Embryo; D002823:Chorion / Q000098:blood supply; D006224:Cricetinae; D016222:Fibroblast Growth Factor 2 / Q000037:antagonists & inhibitors / Q000494:pharmacology / Q000502:physiology*; D006493:Heparin / Q000737:chemistry / Q000494:pharmacology*; D006497:Heparan Sulfate / Q000096:biosynthesis / Q000494:pharmacology; D006801:Humans; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D008969:Molecular Sequence Data; D018919:Neovascularization, Physiologic / Q000187:drug effects / Q000502:physiology*; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics / Q000502:physiology*; D051496:Receptor, Fibroblast Growth Factor, Type 1; D017468:Receptors, Fibroblast Growth Factor / Q000235:genetics / Q000502:physiology*; D011994:Recombinant Proteins / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D013329:Structure-Activity Relationship; D014162:Transfection
D016222:Fibroblast Growth Factor 2; D006493:Heparin; D006497:Heparan Sulfate; D019950:Mitogen-Activated Protein Kinase 1; D010446:Peptide Fragments; D020794:Receptor Protein-Tyrosine Kinases; D051496:Receptor, Fibroblast Growth Factor, Type 1; D017468:Receptors, Fibroblast Growth Factor; D011994:Recombinant Proteins; C496348:FGFR1 protein, human