The vascular endothelial growth factor (VEGF) family consists of critical cytokines that are implicated in controlling vascular survival and angiogenic sprouting. Recently VEGF inhibitors have been approved by the FDA to treat diseases of hypervascularization (cancer and macular degeneration), while increasing VEGF expression is a major research avenue for ischemic diseases such as peripheral artery disease and coronary artery disease, though clinical trials are as yet unsuccessful. VEGF is involved in at least 70 diseases as either cause or therapeutic target Regulation of VEGF signaling is therefore of critical importance for many therapeutic strategies. Recent evidence suggests that more VEGF is bound to the extracellular matrix in vivo than freely diffuses, and that these matrix-binding isoforms of VEGF control branching frequency and network density in vivo. The presentation of VEGF to the receptors by a matrix molecule may initiate a distinct signaling mode, but traditional in vitro cell culture models are unable to differentiate the soluble VEGF signal from the matrix-bound VEGF signal. In this proposal, we develop a combined experimentalcomputational approach to separate the soluble and matrix-bound VEGF signals. Using novel or available fibronectin mutants that do not bind VEGF (Aim 1), we will use state-of-the-art micropatteming techniques to plate endothelial cells on a substrate with gradients of VEGF binding ability (Aim 2). In vitro assays of proliferation, migration and survival will definitively show whether soluble VEGF or matrix-bound VEGF is the more potent stimulator of these critical endothelial cell decisions (Aim 2). We then propose to use in vivo transfection techniques to increase VEGF gradients and to block presentation of matrix-bound VEGF to receptor tyrosine kinases in vivo (Aim 3). This will test whether the in vitro endothelial cell culture is a good model of the decision-making of endothelial cells in vivo.

Public Health Relevance

to public health: Inhibition or upregulation of yascular endpthelljaj groyvth factor (VEGF) is a therapeutic target in over 70 diseases as diverse as cahcelr, cororiafy artery disease and diabetic '?' retinopathy. The proposed research uses a novel combined computational and experimental method to elicit how VEGF initiates its signals and, if successful, will better define how to target it therapeutically.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Transition Award (R00)
Project #
5R00HL093219-04
Application #
8127746
Study Section
Special Emphasis Panel (NSS)
Program Officer
Gao, Yunling
Project Start
2009-09-10
Project End
2012-07-03
Budget Start
2011-08-01
Budget End
2012-07-03
Support Year
4
Fiscal Year
2011
Total Cost
$248,873
Indirect Cost
Name
Johns Hopkins University
Department
Biomedical Engineering
Type
Schools of Medicine
DUNS #
001910777
City
Baltimore
State
MD
Country
United States
Zip Code
21218
Chappell, John C; Cluceru, Julia G; Nesmith, Jessica E et al. (2016) Flt-1 (VEGFR-1) coordinates discrete stages of blood vessel formation. Cardiovasc Res 111:84-93
Clegg, Lindsay Wendel; Mac Gabhann, Feilim (2015) Site-Specific Phosphorylation of VEGFR2 Is Mediated by Receptor Trafficking: Insights from a Computational Model. PLoS Comput Biol 11:e1004158
Clegg, Lindsay E; Mac Gabhann, Feilim (2015) Systems biology of the microvasculature. Integr Biol (Camb) 7:498-512
Walpole, J; Chappell, J C; Cluceru, J G et al. (2015) Agent-based model of angiogenesis simulates capillary sprout initiation in multicellular networks. Integr Biol (Camb) 7:987-97
Clegg, Lindsay E; Mac Gabhann, Feilim (2015) Molecular mechanism matters: Benefits of mechanistic computational models for drug development. Pharmacol Res 99:149-54
Vempati, Prakash; Popel, Aleksander S; Mac Gabhann, Feilim (2014) Extracellular regulation of VEGF: isoforms, proteolysis, and vascular patterning. Cytokine Growth Factor Rev 25:1-19
Logsdon, Elizabeth A; Finley, Stacey D; Popel, Aleksander S et al. (2014) A systems biology view of blood vessel growth and remodelling. J Cell Mol Med 18:1491-508
Tan, Wan Hua; Popel, Aleksander S; Mac Gabhann, Feilim (2013) Computational model of VEGFR2 pathway to ERK activation and modulation through receptor trafficking. Cell Signal 25:2496-510
Peirce, Shayn M; Mac Gabhann, Feilim; Bautch, Victoria L (2012) Integration of experimental and computational approaches to sprouting angiogenesis. Curr Opin Hematol 19:184-91
Liu, Gang; Mac Gabhann, Feilim; Popel, Aleksander S (2012) Effects of fiber type and size on the heterogeneity of oxygen distribution in exercising skeletal muscle. PLoS One 7:e44375

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