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HMG-CoA Reductase Inhibitors Prevent Migration of Human Coronary Smooth Muscle Cells Through Suppression of Increase in Oxidative Stress

In vitro and in vivo evidence of a decrease in vascular smooth muscle cell (SMC) migration induced by 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors has been reported. When added to SMC cultures for 6 hours, the HMG-CoA reductase inhibitors fluvastatin, simvastatin, and pravastatin at 1 μmol/L resulted in a 48%, 50%, and 16% suppression, respectively, of human coronary SMC migration; these reductions mirrored the suppression in oxidative stress induced by 1 μmol/L lysophosphatidylcholine (lyso-PC) of 50%, 53% and 19%, respectively. The hydroxylated metabolites of fluvastatin, M2 and M3, at 1 μmol/L also suppressed the enhancement of SMC migration by 58% and 45% and the increase in oxidative stress induced by lyso-PC of 58% and 49%, respectively. Lyso-PC activated phospholipase D and protein kinase C (PKC), and this activation was also suppressed by HMG-CoA reductase inhibitors. The inhibition of phospholipase D and PKC was reversed by 100 μmol/L mevalonate, its isoprenoid derivative, farnesol, and geranylgeraniol but not by 10 μmol/L squalene. Antisense oligodeoxynucleotides at 5 μmol/L to PKC-α, but not those to the PKC-β isoform, suppressed the lyso-PC–mediated increases in SMC migration and oxidative stress. These findings suggest that HMG-CoA reductase inhibitors have direct antimigratory effects on the vascular wall beyond their effects on plasma lipids and that they might exert such antimigratory effects via suppression of the phospholipase D– and PKC (possibly PKC-α)-induced increase in oxidative stress, which might in turn prevent significant coronary artery disease.