Differential Receptor Binding and Regulatory Mechanisms for the Lymphangiogenic Growth Factors Vascular Endothelial Growth Factor (VEGF)-C and -D.

Abstract

VEGF-C and VEGF-D are secreted glycoproteins that induce angiogenesis and lymphangiogenesis in cancer, thereby promoting tumor growth and spread. They exhibit structural homology and activate VEGFR-2 and VEGFR-3, receptors on endothelial cells that signal for growth of blood vessels and lymphatics. VEGF-C and VEGF-D were thought to exhibit similar bioactivities, yet recent studies indicated distinct signaling mechanisms (e.g. tumor-derived VEGF-C promoted expression of the prostaglandin biosynthetic enzyme COX-2 in lymphatics, a response thought to facilitate metastasis via the lymphatic vasculature, whereas VEGF-D did not). Here we explore the basis of the distinct bioactivities of VEGF-D using a neutralizing antibody, peptide mapping, and mutagenesis to demonstrate that the N-terminal α-helix of mature VEGF-D (Phe93-Arg108) is critical for binding VEGFR-2 and VEGFR-3. Importantly, the N-terminal part of this α-helix, from Phe93 to Thr98, is required for binding VEGFR-3 but not VEGFR-2. Surprisingly, the corresponding part of the α-helix in mature VEGF-C did not influence binding to either VEGFR-2 or VEGFR-3, indicating distinct determinants of receptor binding by these growth factors. A variant of mature VEGF-D harboring a mutation in the N-terminal α-helix, D103A, exhibited enhanced potency for activating VEGFR-3, was able to promote increased COX-2 mRNA levels in lymphatic endothelial cells, and had enhanced capacity to induce lymphatic sprouting in vivo This mutant may be useful for developing protein-based therapeutics to drive lymphangiogenesis in clinical settings, such as lymphedema. Our studies shed light on the VEGF-D structure/function relationship and provide a basis for understanding functional differences compared with VEGF-C.

• Authors: Natalia Davydova, Nicole C Harris, Sally Roufail, Sophie Paquet-Fifield, Musarat Ishaq, Victor A Streltsov, Steven P Williams, Tara Karnezis, Steven A Stacker, Marc G Achen
• Journal: The Journal of biological chemistry (J Biol Chem) Vol. 291 Issue 53 Pg. 27265-27278 (12 30 2016) ISSN: 1083-351X [Electronic] United States
• PMID: 27852824 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Chemical References

• Antibodies, Neutralizing
• VEGFC protein, human
• VEGFD protein, human
• Vascular Endothelial Growth Factor C
• Vascular Endothelial Growth Factor D
• Vascular Endothelial Growth Factor Receptor-2
• Vascular Endothelial Growth Factor Receptor-3

Topics

• Animals
• Antibodies, Neutralizing
• Cells, Cultured
• Dermis (metabolism, pathology)
• Endothelium, Vascular (metabolism, pathology)
• Female
• Humans
• Lymphangiogenesis
• Lymphatic Vessels (metabolism, pathology)
• Mice, Inbred NOD
• Mice, SCID
• Mutagenesis, Site-Directed
• Mutation (genetics)
• Neovascularization, Pathologic (metabolism, pathology)
• Signal Transduction
• Vascular Endothelial Growth Factor C (chemistry, genetics, metabolism)
• Vascular Endothelial Growth Factor D (chemistry, genetics, metabolism)
• Vascular Endothelial Growth Factor Receptor-2 (genetics, metabolism)
• Vascular Endothelial Growth Factor Receptor-3 (genetics, metabolism)