Changes in proteomic features induced by insulin on vascular smooth muscle cells from spontaneous hypertensive rats in vitro.

Hyperinsulinemia is a risk factor in atherosclerosis formation that it stimulated vascular smooth muscle cells (VSMCs) proliferation and migration. To understand the underlying molecular mechanism involved in the processes of cellular response to insulin, VSMCs from Wistar-Kyoto rat (WKY) and spontaneous hypertensive rat (SHR) were isolated and cultured, and its proteome was comparatively analyzed with normal control by two-dimensional gel electrophoresis (2-DE). Results showed that the proliferation of VSMCs from SHR be more sensitive to insulin stimulation than that VSMCs from WKY. The detectable spots ranged from 537 to 608 on the gels in VSMCs of SHR, and 413 ± 31 spots in VSMCs of WKY. The different expressed protein spots in VSMCs of SHR were then isolated and measured by matrix-assisted desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS). A total of 18 spots showed a sharp clear spectrum, and 13 spots matched with the known proteins from database. These proteins were mainly involved in cytoskeleton, glycometabolism, and post-translational processes. Among these proteins, OPN and matrix gla protein were up-regulated expression proteins, while α-SM actin was down-regulated. Furthermore, these preliminarily identified proteins confirmed by RT-PCR and western blotting analysis were coincident with the changes in 2-DE check. In addition, the cytoskeleton changes and migration rate of VSMCs from SHR treated by insulin increased significantly. The results showed that insulin plays a crucial role in activating proliferation and migration of VSMCs, by regulating the phenotype switch of VSMCs.