Morphological, functional, and gene expression studies have established the phenotypic plasticity of smooth muscle cells (SMCs). These cells have been shown to respond to environmental stimulants such as extracellular matrix and growth factors. | Turkish Journal of Biology Turk J Biol (2013) 37: 414-425 © TÜBİTAK doi: Research Article Proteomic evidence for the plasticity of cultured vascular smooth muscle cells 1 1 1 1 Ahmet Tarık BAYKAL , Betül BAYKAL , Müge SERHATLI , Zelal ADIGÜZEL , 2 1 1,3 1, Mehmet Altuğ TUNÇER , Ömer KAÇAR , Kemal BAYSAL , Ceyda AÇILAN AYHAN * 1 Genetic Engineering and Biotechnology Institute, TÜBİTAK Marmara Research Center, Gebze, Kocaeli, Turkey 2 Kartal Koşuyolu Education and Research Hospital, Republic of Turkey Ministry of Health, İstanbul, Turkey 3 Department of Biochemistry, Medical Faculty, Dokuz Eylül University, İnciraltı, İzmir, Turkey Received: Accepted: Published Online: Printed: Abstract: Morphological, functional, and gene expression studies have established the phenotypic plasticity of smooth muscle cells (SMCs). These cells have been shown to respond to environmental stimulants such as extracellular matrix and growth factors. Cellular changes can vary between extremes defined as the contractile and synthetic states. Various growth factors have been shown to have profound effects on the phenotype of these cells. In this study, we intended to investigate the effects of growth factor-rich medium on the protein expression of vascular SMCs in culture. Interestingly, transiently changing the type of medium did not result in any apparent morphological differences, yet we hypothesized that some cellular factors might still be altered. In order to understand what kind of intracellular molecular changes should be expected to occur during the medium change, we analyzed global protein expression changes using nano-LC-MS/MS in smooth muscle cell cultures that were isolated and grown in one medium formulation and temporarily switched to the other. Our data indicate that proteins playing a role in energy metabolism (glycolysis), translation, and folding of proteins .