title: Determinants of Notch-3 receptor expression and signaling in vascular smooth muscle cells: implications in cell-cycle regulation.
abstract: The Notch family of receptors and ligands plays an important role in cell fate determination, vasculogenesis, and organogenesis. Mutations of the Notch-3 receptor result in an arteriopathy that predisposes to early-onset stroke. However, the functional role of the Notch signaling pathway in adult vascular smooth muscle cells (VSMCs) is poorly characterized. This study documents that the Notch-3 receptor, the ligand Jagged-1, and the downstream transcription factor, HESR-1, are expressed in the normal adult rat carotid artery, and that this expression is modulated after vascular injury. In cultured VSMCs, both angiotensin II and platelet-derived growth factor (PDGF) markedly downregulated Notch-3 and Jagged-1 through ERK-dependent signaling mechanisms and prevented the glycosylation of Jagged-1. The downregulation of Jagged-1 and Notch-3 was associated with a decrease in CBF-1-mediated gene transcription activation and a fall in the mRNA levels of the downstream target transcription factor HESR-1. To test the hypothesis that the Notch pathway was coupled to growth regulation, we generated VSMC lines overexpressing the constitutively active form of Notch-3 (A7r5-N3IC). These cells exhibited a biphasic growth behavior in which the growth rate was retarded during the subconfluent phase and failed to decelerate at postconfluence. The lack of cell-cycle arrest in postconfluent A7r5-N3IC was associated with an attenuated upregulation of the cell-cycle inhibitor p27(kip) relative to control cells. This study documents the regulation of the Jagged-1 and Notch-3 genes in VSMCs by growth factor stimulation as well as a role for Notch-3 as a determinant of VSMC growth.
authors.affiliation: Cardiovascular Research Institute, Morehouse School of Medicine, Atlanta, Ga 30310, USA.
authors.forename: Alexandre H
authors.initials: AH
authors.lastname: Campos
authors.forename: Wenli
authors.initials: W
authors.lastname: Wang
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Pollman
authors.forename: Gary H
authors.initials: GH
authors.lastname: Gibbons
mesh_terms: D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins; D002135:Calcium-Binding Proteins; D002339:Carotid Arteries / Q000378:metabolism / Q000473:pathology; D002340:Carotid Artery Diseases / Q000378:metabolism / Q000473:pathology; D002453:Cell Cycle / Q000502:physiology*; D018797:Cell Cycle Proteins / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D050760:Cyclin-Dependent Kinase Inhibitor p27; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004195:Disease Models, Animal; D015536:Down-Regulation / Q000187:drug effects; D029721:Drosophila Proteins; D006031:Glycosylation / Q000187:drug effects; D051819:Immunoglobulin J Recombination Signal Sequence-Binding Protein; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism; D036341:Intercellular Signaling Peptides and Proteins; D000072100:Jagged-1 Protein; D008297:Male; D008565:Membrane Proteins / Q000096:biosynthesis / Q000235:genetics; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D009687:Nuclear Proteins; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D051881:Receptor, Notch1; D051883:Receptor, Notch2; D011956:Receptors, Cell Surface / Q000096:biosynthesis / Q000235:genetics; D000072099:Serrate-Jagged Proteins; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins / Q000378:metabolism
chemical_list: D000804:Angiotensin II; D051792:Basic Helix-Loop-Helix Proteins; D002135:Calcium-Binding Proteins; D018797:Cell Cycle Proteins; D050760:Cyclin-Dependent Kinase Inhibitor p27; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D051819:Immunoglobulin J Recombination Signal Sequence-Binding Protein; D019476:Insect Proteins; D036341:Intercellular Signaling Peptides and Proteins; D000072100:Jagged-1 Protein; D008565:Membrane Proteins; D020928:Mitogen-Activated Protein Kinases; D009687:Nuclear Proteins; D010982:Platelet-Derived Growth Factor; D011506:Proteins; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D051881:Receptor, Notch1; D051883:Receptor, Notch2; D011956:Receptors, Cell Surface; D000072099:Serrate-Jagged Proteins; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; C493962:Cdkn1b protein, rat; C120390:Hey protein, Drosophila; C000606275:Jag1 protein, rat; C497763:Notch1 protein, rat; C497766:Notch2 protein, rat; C497572:Rbpjl2 protein, rat; C000606278:Ser protein, Drosophila