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dc.contributor.authorMoore, Andrew Douglas
dc.date.accessioned2015-09-22T08:56:11Z
dc.date.available2015-09-22T08:56:11Z
dc.date.issued2014-12-03
dc.identifier.citationMoore, AD. 2014. A Study of Effects on MMP14 Transcriptional Regulation and Angiogenesis by Hypoxia and Statins. Queen Mary University of Londonen_US
dc.identifier.urihttp://qmro.qmul.ac.uk/xmlui/handle/123456789/8802
dc.descriptionPhDen_US
dc.description.abstractAtheromas contain hypoxic areas which upregulate HIF1α expression, promoting angiogenesis and unstable lesion formation. Simvastatin stabilises atheromas through preventing rupture and neovascularisation. Atheromas express matrix metalloproteinase 14 (MMP14) which degrades matrix proteins and promotes neovascularisation. MMP14 is upregulated by hypoxia and contains Hypoxic-Inducible Factor (HIF) recognition sequences (5’-RCGTG-3’). My project sought to investigate if HIF1α interacts with the MMP14 promoter to enhance MMP14 expression, and whether simvastatin attenuates this effect, inhibiting angiogenesis. Immunostaining of atheromas identified MMP14 and HIF1α localisation. Protein-DNA binding assays were performed on human umbilical vein endothelial cells (HUVECs) and showed HIF1α bound to the MMP14 promoter in hypoxia, which was significantly decreased by simvastatin. To assess gene regulation, a human MMP14 promoter-firefly luciferase reporter construct was transfected into C166 endothelial cells alongside HIF-overexpression plasmids and mutations of the MMP14 promoter region at HIF recognition sequences. Overexpression of HIF1α and HIF1β increased MMP14 activity which was abolished by introducing the mutations and diminished by simvastatin in a HIF-dependent manner. Immunoblots, flow cytometry, scratch assays and bromodeoxyuridine incorporation showed HIF1α knockdown and simvastatin significantly attenuated hypoxia upregulated MMP14 expression, migration and proliferation in a HIF1α-dependent manner. Angiogenesis was assessed using in vivo sponge angiogenesis assays and ex vivo aortic ring assays cultured in hypoxia or normoxia, with or without 0.1μM simvastatin, and MMP14 inhibitor, utilising HIF1αfl/flTie1Cre+ and wildtype littermates. Simvastatin perturbed angiogenesis through decreasing MMP14 expression in a HIF1α-dependent manner. The results show hypoxia upregulates MMP14 through HIF1α interaction with the MMP14 promoter. Simvastatin attenuates MMP14 upregulation which reduces HIF1α:MMP14 promoter interaction. HIF1α knockdown and simvastatin treated HUVECs show less migration and proliferation, equivalent to that of MMP14 inhibition. Simvastatin inhibits neovascularisation in a HIF1α-dependent manner. These results suggest simvastatin may stabilise atheromas through inhibiting MMP14 driven angiogenesis which may have further implications in the treatment of atherosclerosis.en_US
dc.description.sponsorshipBritish Heart Foundation [FS/11/28/28758].en_US
dc.language.isoenen_US
dc.publisherQueen Mary University of Londonen_US
dc.subjectAtheromasen_US
dc.subjectmatrix metalloproteinase 14en_US
dc.subjectangiogenesisen_US
dc.subjectClinical Pharmacologyen_US
dc.titleA Study of Effects on MMP14 Transcriptional Regulation and Angiogenesis by Hypoxia and Statinsen_US
dc.typeThesisen_US
dc.rights.holderThe copyright of this thesis rests with the author and no quotation from it or information derived from it may be published without the prior written consent of the author


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