Expression level of miR-155 in peripheral blood

Abstract Objective To investigate the relationship between the expression level of miR–155 and the severity of coronary lesion, and explore the action mechanism. Methods Peripheral blood mononuclear cells (PBMC) were isolated form blood simple from patients with acute myocardial infarction (AMI), unstable angina (UAP), stable angina (SAP) and chest pain syndrome (CPS). RT–PCR was performed to analysis the expression level of miR–155 in peripheral blood mononuclear cells, plasma and RAW264.7 macrophagocyte. MTT was used to analyze the cell viability of OxLDL treated RAW264.7 macrophagocyte. Results The expression level of miR–155 in blood sample from coronary heart disease patients was much lower than in the blood sample of non–coronary heart disease ( P P r =0.861, P =0.000). OxLDL can induce the expression of miR–155 in RAW264.7 macrophagocyte, decrease the cell viability of RAW264.7 macrophagocyte, and with the concentration and the treatment time of OxLDL increased, the effort become more obvious. The inhibition effort of OxLDL to RAW264.7 macrophagocyte with high miR–155 expression is much lower than the control group, and it is statistically significant after treated for 12, 24 and 48 h. Conclusions miR–155 plays a protective role in the progression of atherosclerosis, and it may be achieved by reducing the apoptosis effort of OxLDL to RAW264.7 macrophagocyte.