Ectopic decorin expression up-regulates VEGF expression in mouse cerebral endothelial cells via activation of the transcription factors Sp1, HIF1alpha, and Stat3.
We demonstrate that a proteoglycan decorin (DCN) up-regulates the vascular endothelial growth factor (VEGF) expression with activation of VEGF regulating transcription factors Sp1, hypoxia-inducible factor 1alpha (HIF1alpha), and signal transducer and activator of transcription 3 (Stat3) via epidermal growth factor receptor (EGFR), mitogen-activated protein kinase extracellular signal-regulated kinase 1/2 (ERK1/2), and protein kinase B (AKT) pathways in DCN transfected mouse cerebral endothelial (MCE) cells. Treatment with pharmacological inhibitors and small interfering RNAs reveal that induction and activation of Sp1, HIF1alpha, and Stat3 facilitate their nuclear localization and binding to their specific motifs of the VEGF promoter and induce VEGF expression via two independent pathways, DCN/EGFR/phosphoinositide-3 kinase/AKT and DCN/EGFR/ERK1/2, respectively, in DCN synthesizing MCE cells. The cell type specific glycosylation protects Sp1 and HIF1alpha from proteosome degradation and plays an important and novel role in the regulation of VEGF in DCN transfected MCE cells. Induction of gelatinases (matrix metalloproteinase 2 and 9), the serine protease tissue plasminogen activator and plasmin by DCN transfection in MCE cells leads to extracellular proteolysis and to release of matrix-bound VEGF and activation of angiogenesis. In this study, we demonstrate that two independent downstream signal pathways, DCN/EGFR/ERK1/2 and DCN/EGFR/phosphoinositide-3 kinase/AKT, mediate up-regulation and activation of transcription factors of VEGF such as HIF1alpha, Stat3, and Sp1 and increase VEGF transcription and angiogenesis in MCE cells.
Santra
Manoranjan
M
Department of Neurology, Henry Ford Hospital, Detroit, Michigan 48202, USA.
Santra
Sutapa
S
Zhang
Jing
J
Chopp
Michael
M
D000704:Analysis of Variance; D000818:Animals; D002540:Cerebral Cortex / Q000166:cytology*; D047369:Chromatin Immunoprecipitation / Q000379:methods; D058575:Decorin; D024202:Electrophoretic Mobility Shift Assay / Q000379:methods; D042783:Endothelial Cells / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D016326:Extracellular Matrix Proteins / Q000378:metabolism* / Q000494:pharmacology; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008954:Models, Biological; D018919:Neovascularization, Physiologic / Q000187:drug effects / Q000502:physiology; D011509:Proteoglycans / Q000378:metabolism* / Q000494:pharmacology; D034741:RNA, Small Interfering / Q000494:pharmacology; D050796:STAT3 Transcription Factor / Q000235:genetics / Q000378:metabolism; D016329:Sp1 Transcription Factor / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014162:Transfection / Q000379:methods; D015854:Up-Regulation / Q000187:drug effects* / Q000502:physiology; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*
C546879:Dcn protein, mouse; D058575:Decorin; D004791:Enzyme Inhibitors; D016326:Extracellular Matrix Proteins; C497443:Hif1a protein, mouse; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D011509:Proteoglycans; D034741:RNA, Small Interfering; D050796:STAT3 Transcription Factor; D016329:Sp1 Transcription Factor; C494087:Stat3 protein, mouse; D014157:Transcription Factors; D042461:Vascular Endothelial Growth Factor A