title: A proteomic approach to the investigation of early events involved in vascular smooth muscle cell activation.
abstract: Vascular smooth muscle cells (VSMC) are mature cells that maintain great plasticity. This distinctive feature is the basis of the VSMC migration and proliferation involved in cardiovascular diseases. We have used a proteomic approach to the molecular changes that promote the switch of VSMC from having a quiescent to activated-proliferating phenotype. In particular, we have focused on modulations occurring during tyrosine-phosphorylation following cell activation by serum or single growth factors, such as insulin-like growth factor 1 or platelet-derived growth factor. A comparison of two-dimensional polyacrylamide gel profiles from quiescent or activated-proliferating VSMC has allowed us to recognize a number of differences in protein expression. Several differentially expressed proteins have been identified by mass spectrometry, and their time-course changes during tyrosine-phosphorylation have been documented from time zero till 48 h after stimulation. We have documented a general decrease of the tyrosine-phosphorylation level within the first few minutes after stimulation followed by a recovery that is quick and dramatic for some chaperones and redox enzymes but not so significant for enzymes of glucose metabolism. With regard to cytoskeleton components, no remarkable fluctuations have been detected at the earliest time points, except for those relative to alpha-actin, which displays an impressive decrease. A comparison of the early stages of cell stimulation after the administration of serum or single growth factors has brought to light important differences in the phosphorylation of chaperones, thereby suggesting their crucial role in VSMC activation.
authors.affiliation: Laboratory of Molecular and Gene Therapy, Clinical Physiology Institute CNR, Pisa, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Boccardi
authors.forename: Antonella
authors.initials: A
authors.lastname: Cecchettini
authors.forename: Anna
authors.initials: A
authors.lastname: Caselli
authors.forename: Guido
authors.initials: G
authors.lastname: Camici
authors.forename: Monica
authors.initials: M
authors.lastname: Evangelista
authors.forename: Alberto
authors.initials: A
authors.lastname: Mercatanti
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Rainaldi
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Citti
mesh_terms: D000818:Animals; D049109:Cell Proliferation; D015180:Electrophoresis, Gel, Two-Dimensional; D013058:Mass Spectrometry; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000378:metabolism*; D010766:Phosphorylation; D019000:Phosphotyrosine / Q000378:metabolism; D011506:Proteins / Q000032:analysis / Q000737:chemistry; D040901:Proteomics; D013552:Swine; D013997:Time Factors
chemical_list: D011506:Proteins; D019000:Phosphotyrosine