Supression of SIRT1 in angiogenesis of endothelial cells induced by HCMV infection

Abstract

Background Human cytomegalovirus (HCMV) is closely related to diseases including atherosclerosis, transplanted vascular sclerosis and arterial restenosis. It has been proved that angiogenesis induced by HCMV infection could result in vascular diseases. This article aims to investigate the mechanism of angiogenesis induced by HCMV infection in endothelial cells. Methods Endothelial cells (EA.hy926 cells) were divided into HCMV infected group and mock infected group. The cells were collected at 2, 6, 12 and 24 h after infection. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were used to analyze SIRT1 mRNA and protein levels. Endothelial cells were incubated respectively by Resveratrol and SIRT1 small interference RNA (siRNA) for 2 h before infection. Twenty⁃four hours after infection, the proliferation, migration and tubule formation of cells were assessed by CCK-8, migration assay and tubule formation assay to detect the angiogenic response of endothelial cells. Results Compared to mock infected group, the expression of SIRT1 mRNA in HCMV infected group remained unchanged (F = 1.395, P = 0.304), but the expression of SIRT1 protein decreased gradually (F = 23.927, P = 0.000). Under the treatment of Resveratrol and SIRT1 siRNA, migration (P = 0.008, 0.003) and tubule formation (P = 0.012, 0.008) of endothelial cells increased or reduced. The proliferation, however, remained unchanged (P = 0.969, 0.948). Conclusion HCMV infection promotes proliferation, migration and tubule formation of endothelial cells, and its mechanism may be related to the supression of SIRT1.