A proteomic approach to the investigation of early events involved in the activation of vascular smooth muscle cells.
Vascular smooth muscle cells (VSMC) are mature cells that maintain great plasticity. This distinctive quality is the basis of the migration and proliferation of VSMC in cardiovascular diseases. We have investigated, via a proteomic approach, the molecular changes that promote VSMC switching from a quiescent to an activated-proliferating phenotype. In particular, we focus on the modulation in tyrosine phosphorylation that occurs in cell activation by serum or by single growth factors, such as insulin-like growth factor 1 (IGF-1) or platelet-derived growth factor (PDGF-BB). A comparison of profiles from two-dimensional polyacrylamide gel electrophoresis analysis of quiescent and activated-proliferating VSMC has revealed a number of differences in protein expression. Several differentially expressed proteins have been identified by mass spectrometry, and their changes during the time course of tyrosine phosphorylation have been documented from time zero up to 48 h after stimulus. The tyrosine-phosphorylation level generally decreases within a few minutes of stimulation, followed by a rapid dramatic recovery of some chaperones and redox enzymes, but no significant recovery for glucose metabolism enzymes. With respect to cytoskeleton components, no remarkable fluctuations have been detected at the earliest time points, except for those relating to alpha-actin, which displays an impressive decrease. A comparison of the early stages of cell stimulation after serum or after single growth factor administration has revealed important differences in the phosphorylation of chaperones, thereby suggesting their crucial role in VSMC activation.
Boccardi
Claudia
C
Laboratory of Molecular and Gene Therapy, Clinical Physiology Institute CNR, Via Moruzzi 1, 56124 Pisa, Italy.
Cecchettini
Antonella
A
Caselli
Anna
A
Camici
Guido
G
Evangelista
Monica
M
Mercatanti
Alberto
A
Rainaldi
Giuseppe
G
Citti
Lorenzo
L
D043925:Angiogenesis Inducing Agents / Q000494:pharmacology*; D000818:Animals; D000077214:Becaplermin; D002478:Cells, Cultured; D003599:Cytoskeleton; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D013058:Mass Spectrometry; D009124:Muscle Proteins / Q000096:biosynthesis*; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism*; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000378:metabolism; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology*; D020543:Proteome / Q000096:biosynthesis*; D040901:Proteomics; D020574:Proto-Oncogene Proteins c-sis; D034421:Sus scrofa; D013997:Time Factors
D043925:Angiogenesis Inducing Agents; D009124:Muscle Proteins; D010982:Platelet-Derived Growth Factor; D020543:Proteome; D020574:Proto-Oncogene Proteins c-sis; D000077214:Becaplermin; D007334:Insulin-Like Growth Factor I