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dc.contributor.authorRittler, Matthew Roberten_US
dc.date.accessioned2014-03-14T20:08:41Z
dc.date.available2014-03-14T20:08:41Z
dc.date.issued2008-03-17en_US
dc.identifier.otheretd-03312008-183133en_US
dc.identifier.urihttp://hdl.handle.net/10919/26569
dc.description.abstractThe vascular endothelial growth factor (VEGF) family is prominently involved in angiogenesis, the formation of new vasculature. Overexpression has been linked to pathological conditions including solid tumor growth. Responses to VEGF are mediated by Flt-1 and KDR, two cell-surface receptors selectively expressed by vascular endothelial cells. A secreted form of Flt-1 (sFlt1) retains high affinity for VEGF and can compete for VEGF binding, thereby inhibiting angiogenic responses. In this study, a computational model of this ligand-receptor binding system is used to quantitatively describe the activation of KDR signaling by VEGF and its inhibition by sFlt-1. The model consists of a system of 12 ordinary differential equations, based on mass action kinetics, which describe, based on mass-action kinetics, the formation and disappearance of receptor-ligand complexes competent to transduce a VEGF signal. Cell-based assays were used to test predictions of the in silico model by measuring dynamics of 1) KDR tyrosine hosphorylation and 2) generation of intracellular second messengers in response to VEGF stimulation in the presence and absence of sFlt-1. Results indicate that the model predicts well the maximal activation in the presence of VEGF-A or the KDR-selective agonist VEGF-E. Subsequent characteristics of binding, such as time-to-peak activations, were less realistically modeled, suggesting that the mathematical descriptions of certain receptor fates (receptor internalization, sequestration or externalization) may need refinement. Also presented are the results of KDR activation experiments in the simultaneous presence of VEGF-A, sFlt1, and the Flt1-selective agonist placental growth factor (PlGF). Here, the model predicts accurately the percentage of inhibition of maximal activation when sFlt-1 is present in the system. Finally, a revised model that includes receptor heterodimerization is presented that suggests sFlt-1 can more effectively inhibit VEGF binding and activation when acting in a dominant negative fashion. Overall, the findings support the idea that the early events in VEGF signaling can be modeled successfully. A natural extension of the model, refined based on experimental testing, will be its application to normal physiological systems.en_US
dc.publisherVirginia Techen_US
dc.relation.haspartRittler_Dissertation_Final_ETD.pdfen_US
dc.rightsI hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Virginia Tech or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report.en_US
dc.subjectreceptorsen_US
dc.subjectcomputational modelen_US
dc.subjectVEGFen_US
dc.subjectsFlt-1en_US
dc.titleModeling of interactions between vascular endothelial growth factor family members and their receptors KDR and Flt-1.en_US
dc.typeDissertationen_US
dc.contributor.departmentBiomedical Engineering and Sciencesen_US
dc.description.degreePh. D.en_US
thesis.degree.namePh. D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineBiomedical Engineering and Sciencesen_US
dc.contributor.committeechairHuckle, William R.en_US
dc.contributor.committeememberSible, Jill C.en_US
dc.contributor.committeememberGoldstein, Aaron S.en_US
dc.contributor.committeememberEyestone, Willard H.en_US
dc.contributor.committeememberWilliams, Kimberly Forstenen_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-03312008-183133/en_US
dc.date.sdate2008-03-31en_US
dc.date.rdate2008-04-10
dc.date.adate2008-04-10en_US


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