Identification of proteins involved in insulin stimulation in vascular smooth muscle cells of SHR rats

AIM: To identify proteins involved in insulin stimulation and the molecular mechanism of proliferation and migration in vascular smooth muscle cells (VSMCs). METHODS: A series of methods, including 2-D electrophoresis, PDQuest software analysis of 2-DE gels, peptide mass fingerprinting based on matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) and SWISS-PROT database searching, were used to separate and identify the differentially expressed proteins. The difference of some proteins was proved by Western blotting. Proliferation and migration of VSMCs treated with insulin were also observed. RESULTS: DNA synthesis were increased in VSMCs. ~3H-thymidine incorporation in VSMCs from SHR (14.40±0.85) was higher than that in VSMCs from WKY (9.21±0.93, P0.05). Migration rate of VSMCs from SHR was about 1.8 times higher than that in VSMCs from WKY (P0.05). Image analysis revealed that averages of protein spots detected were 502±32 and 612±39 in control VSMCs and in cells treated with insulin, respectively. Result of western blotting confirmed that α-SM protein was down-regulated and matrix Gla, OPN proteins were up-regulated by insulin stimulation. CONCLUSION: The results suggest that the differential proteomic analysis may be useful to study related proteins involved in insulin-regulated proliferation in VSMCs.