Background: Statins are lipid-lowering drugs that can simultaneously evoke pleiotropic effects on cardioprotection, vasodilation, and diabetes prevention. Recently, statins have been reported to be able to activate the AMP-activated protein kinase, thereby up-regulating sirtuin (SIRT) that functions as non-histone deacetylases. Therefore, it is essential to investigate the post-translational acetylome that might explain the mechanism of statin-modulated pleiotropic effects.
Methods: Endothelial cells EAhy 926 treated with rosuvastatin were used to monitor the expression of SIRTs proteins. The protein lysates of both mock- and rosuvastatin-treated cells were further separated by two- dimensional gel electrophoresis coupled with western blotting analysis. The significantly changed acetyl- containing proteins detected by using an anti-acetyl lysine antibody were collected from another preparative gel for mass spectrometric assay to identify the acetylated site in the proteins.
Results: Rosuvastatin treatment was shown to increase the SIRT1 expression when compared with SIRT2. Among 100 detected proteins with acetylated signal, 12 showed an increased level of acetylation, whereas 6 showed a decreased level of acetylation (deacetylation). The acetylated lysine (K) sites of 3 heat shock proteins, i.e., HSP47/K(165), HSP70/K(380), and heat shock-inducible protein/K(417), were determined. We also found that beta-filamin, elongation factor, galectin and hCG22067 have 2 acetylated lysine sites in their peptide sequences. These dynamic acetylations might alter the protein's function and are thought to be important in regulating statin-mediated pleiotropic effect.
Conclusions: Our study provided a feasible methodology for detecting acetylated proteins. This acetylome information may be utilized to explain, at least partially, the mechanisms of statin-derived pleiotropic effects.
Key words: Acetylation/deacetylation; Acetylome; Endothelial cell; Proteomics; Rosuvastatin; Sirtuin.