Study On The Correlation Of OPG And Coronary Atherosclerosis And The Effect Of OPG On Calcification Of HVSMC

Objective: Through observe the level of osteoprotegerin(OPG) in coronary heart disease(CHD) patients serum and the expression of OPG m RNA in calcificated human vascular smooth muscle cells(HVSMC);To investgate the effects of OPG on calcification of human vascular smooth muscle cells.Methods:(1) 59 patients who take coronary angiography( CAG) in our hospital from 2012 December to 2013 May were enrolled in this study.These subjects were divided into two groups according to their CAG outcomes: CHD group(36 cases) and normal group(23 cases). The serum OPG level of each group was measured by enzyme linked immunosorbent assay(ELISA).(2) HVSMC were divided into high phosphorus group and normal group which were cultured with high phosphorus(2.0mmol/L) and ordinary medium respectively. The activity of alkaline phosphatase(AKP) 、 calcium concentration and protein concentration in each group of HVSMC were measured by automatic biochemical analyzer、onycho-ó-phenolphthalein complexone method、BCA method(two quinoline acid method) respectively. The calcification value of HVSMC was standardized by it’s cell protein concentration. Cell climbing pieces were maked and their calcification nodules were observed by fluorescence microscope after Von Kossa staining. The OPG m RNA expression in these two HVSMC groups were checked by real-time quantitative polymerase chain reaction(RT-q PCR).(3)The HVSMC which cultured with high phosphorus(2.0mmol/L) medium were treated with diffent dose of exogenous OPG( the concentration of OPG was 20 ng/ml, 50 ng/ml, 100 ng/ml respectively). And the activity of alkaline phosphatase and calcification value of these HVSMC groups were measured after different level of exogenous OPG treatment.Results:(1).The OPG level in CHD group was higher than that in the normal group significantly [P<0.05];(2). AKP activity, calcification value, m RNA expression of OPG were higher in cells cultured with high phosphate medium significantly, as compared to those in normal phosphate medium [P<0.05].(3). There was a decreasing trend of the cells’ calcification value and AKP activity in the presence of the augmentation of exogenous OPG level in the high phosphate culture medium.The calcification value and AKP activity in the group of HVSMC cultured with high phosphorus which treated with 50 ng /ml and 100 ng /ml of OPG were decreased significantly as compared with the control.Conclusion:(1) The serum levels of OPG is positively correlated with coronary atherosterosis;(2) AKP activity and calcification of human vascular smooth muscle cells can be induced in the high phosphorus culture medium in vitro.And OPG m RNA expression was higher in calcificated human vascular smooth muscle cells than that in control.(3) Calcification of vascular smooth muscle cells can be inhibited by high doses of exogenous OPG through suppression of AKP activity.