Atorvastatin Sensitises Vascular Smooth Muscle Cells, but not Endothelial Cells, to TNF-alpha-induced Cell Death

作者：Giordano Arturo; Romano Simona; Nappo Giovanna; Messina Stefano; Polimeno Michele; Corcione Nicola; Cali Gaetano; Ferraro Paolo; Monaco Mario; Zambrano Nicola; Romano Maria Fiammetta^*

来源：Current Pharmaceutical Design, 2012, 18(38): 6331-6338.

DOI：10.2174/138161212803832245

• Vascular smooth muscle cells
• endothelial cells
• atorvastatin
• TNF-alpha
• cell death

Objective. Stimuli activating vascular smooth muscle cell death can constrain the neointimal response to arterial damage and prevent vascular thickening. Conversely, endothelial cell death increases endothelial dysfunction and thrombosis risk. We investigated the combined effect of atorvastatin and TNF-alpha on vascular cell death. %26lt;br%26gt;Methods and Results. Cell death was investigated in cultures of human aortic smooth muscle cells (VSMCs) and human umbilical vein endothelial cells (HUVECs). Atorvastatin downregulated NF-kappa B and enhanced JNK activity and cell death in VSMC cultured with TNF-alpha. In the absence of TNF-alpha, percentages (mean and StDev) of annexin V positive cells were 17.4 +/- 6.6%, 19.3 +/- 5.9%, 22.9 +/- 9.4% and 35.0 +/- 20.0 % with 0, 1, 3 and 10 mu M atorvastatin, respectively. The cytotoxic effect of statin was significant at the highest dose of 10 mu M (p=0.001). In the presence of TNF-alpha, percentages of annexin V positive cells were 27.1 +/- 10.6%, 34.2 +/- 8.5%, 37.4 +/- 14.6, and 54.1 +/- 20.0% with 0, 1, 3 and 10 mu M atorvastatin, respectively. The cytotoxic effect of statin was significant at each dose used (p %26lt;= 0.02), in the presence of TNF-alpha. The cell death sensitising effect of atorvastatin was apparently mediated by down modulation of PKC beta activity, because it was reproduced by the specific PKC beta inhibitor LY317615 and prevented by the PKC activator phorbol-12-myristate-13-acetate (PMA). This effect was cell context dependent because it was not observed in HUVECs. PKC beta was found to be constitutively active in VSMCs but not in HUVECs, thereby explaining the differential effect among the two cell types. Measurement of phosphoPKC beta protein levels in arterial specimens confirmed increased activation of this kinase in the smooth muscle layer, in comparison with endothelium. We show that PKC beta provides survival signals to vascular smooth muscle cells and not the endothelium. %26lt;br%26gt;Conclusion. Our study suggests that atorvastatin enhances TNF-alpha-induced cell death in vascular smooth muscle- but not endothelial - cells; by a cell-context-dependent mechanism, involving PKC beta inhibition.

• 出版日期2012-12