| Objectives:This study is divided into two parts.The first part is a clinical study.By examining the correlation between the level of high-density lipoprotein-associated phospholipase A2 and the degree of coronary artery disease and HDL in patients with coronary heart disease,the study of coronary artery disease Whether the degree is related to the level of HDL-related enzyme lp-pla2,and provides a theoretical basis for whether lp-pla2 level affects HDL function and its assessment of coronary artery disease severity.The second part of the experimental study was to extract HDL cultured hepatocytes from patients with coronary heart disease and the healthy group of the same period and inject them into adult mice.To observe the HDL receptors in the liver of healthy and coronary heart disease patients--B group The effect of type I scavenger receptor(SRBI)expression was used to investigate the effect of HDL on cholesterol-specific uptake in patients with coronary heart disease,and to provide a theoretical basis for the mechanism of dysfunctional HDL in patients with coronary heart disease.The aims are to study the role of dysfunctional HDL in mouse liver,and to explore the effect on the expression of SR-BI,to provide experimental evidence for the mechanism of dysfunctional HDL.Methods:1.From June 2018 to December 2018,129 patients who were admitted to the cardiology department of the second hospital of Shanxi Medical University and diagnosed as coronary heart disease by coronary angiography were collected.According to the results of coronary angiography,symptoms and ECG,the coronary heart disease group was divided into angina pectoris group and myocardial infarction group,and the pathological changes and number of branches in the result of coronary angiography were recorded.110 normal people who excluded coronary heart disease in the same period were collected as the healthy physical examination group.2.Blood serum and general data of each group were collected,including sex,age,diabetes history,smoking history,drinking history.Venous blood was taken 12 hours after admission to the hospital,and blood glucose,blood lipid,liver and kidney function were measured.3.By enzyme-linked immunosorbent assay(ELISA)to determine the level of HDL related enzyme Lp-PLA2,the coronary heart disease group was divided into four groups according to the quartile method,Q1(203-306,n=36),Q2(307-561,n=32),Q3(562-738,n=31),Q4(739-995,n=30).The degree of coronary stenosis was evaluated by calculating the Gensini score.4.Spss25.0 software was used for statistical analysis to explore whether Lp-PLA2 is related to the degree of coronary stenosis.Spearman correlation analysis was used to compare the correlation between HDL related enzyme Lp-PLA2 and the degree of coronary disease Gensini score.The general data and Lp-PLA2 level of healthy people and coronary heart disease group were compared,and multivariate logistic regression analysis was carried out.According to Gensini score,?32points were classified as severe lesions.The risk factors of coronary heart disease in severe lesions group were analyzed by multivariate logistic regression,and the value of Lp-PLA2 in diagnosing coronary stenosis as severe lesions was further evaluated by ROC curve.5.High density lipoprotein(HDL)was extracted from each group by ultrahigh speed centrifuge,and its concentration and purification were measured.6.Twenty mice were randomly divided into control group,healthy physical examination group,angina pectoris group and myocardial infarction group.50 mg/L of HDL extracted from healthy physical examination group,angina pectoris group and myocardial infarction group was injected into tail vein of mice in each group,once a week,and died after 4 weeks of feeding.The liver of mice was dissected and frozen section was made.The pathological changes of liver tissue were observed by HE staining Oil red O staining was used to observe the lipid drop in the liver tissue,and the total protein in the liver of mice was extracted.Western blot was used to detect the protein expression of class B type I scavenger receptor in the above groups.7.When the cell density was over 80%,HDL(50mg/L)was extracted from healthy subjects,angina patients and myocardial infarction patients for 24 hours.The lipid drop and total protein were evaluated by oil red O staining,and the relative expression of type B type I scavenger receptor protein was measured by Western blot.8.Bioinformatics software predicted the correlation between three groups of HDL and SRBI proteins.Results:1.239 patients(114 males and 125 females)were included in this study.According to the results of coronary angiography,they were divided into normal control group and coronary heart disease group.According to the results of Lp-PLA2 measured by ELISA,the coronary heart disease group was divided into four groups:36 cases of Q1(203-306),32 cases of Q2(307-561),31 cases of Q3(562-738),30 cases of Q4(739-995).2.There was no significant difference between the two groups(P>0.05).In the coronary heart disease group,the levels of diabetes history,Hcy,Cystatin C and Lp-PLA2 were significantly higher than those in the normal control group(P=0.034,P<0.001,P=0.028,P=0.017).3.There was no significant difference in age,gender,NT proBNP,apoB,apoE,lipoprotein?,uric acid,LDH,chol and serum phospholipid among the four groups(P>0.05);Hcy,LDL,dsldl,HDL,ApoA,blood glucose,TG,Cystatin C and thyroid function among the four groups(P<0.05)The level of Lp-PLA2 increased gradually,Hcy increased gradually,Q4 group was significantly higher than q1-3 group,the difference was statistically significant(P<0.05),there was no statistical significance between Q1,Q2,Q3 groups(P>0.05).With the increase of Lp-PLA2 level,Gensini score increased gradually.Q4 group was significantly higher than Q1,Q2,Q3 group,Q3 group was significantly higher than Q1,Q2 group,the difference was statistically significant(P<0.05),Q2was higher than Q1,but the difference between Q1 and Q2 was not statistically significant(P>0.05).With the increase of Lp-PLA2 level,there was no significant relationship between HDL and Lp-PLA2.The difference between group Q4 and group Q3 was statistically significant(P<0.05),and there was no significant difference between the other groups(P>0.05).4.Spearman correlation analysis showed that Lp-PLA2 measured by ELISA was positively correlated with Gensini score(r_s=0.265,P=0.043),and Lp-PLA2 was the risk factor of coronary heart disease(OR=1.721),P=0.004).5.Stepwise logistic regression was used.The results showed that Lp-PLA2 was associated with severe coronary heart disease(Gensini score>32),and was an independent risk factor for severe coronary stenosis(OR=3.231,P=0.013).ROC curve analysis showed that the AUC of Lp-PLA2 was 0.419(95%CI:0.347-0.490)(P=0.049),the diagnostic threshold was 269.79,the sensitivity was 76.8%,and the specificity was 42.4%.6.For the mice injected with HDL from normal people,angina pectoris and myocardial infarction,there was no difference in the tissue structure observed by HE staining;the results of oil red O staining showed that compared with the control group,HDL from normal people was significantly reduced,compared with the control group,HDL from angina pectoris and myocardial infarction was significantly increased,compared with the control group,HDL from acute myocardial infarction was significantly increased Marked increase.7.The results of western blot showed that the expression level of SRBI protein in injectied HDL from healthy people was higher than that in blank control group(P<0.05),the expression level of SRBI protein in liver of mice in angina pectoris group was lower than that in healthy group(P<0.05),the expression level of SRBI protein in liver of mice in myocardial infarction group was lower than that in healthy group(P<0.01).8.The results of oil red O staining showed that the number of lipid droplets of hepatoma cells in HDL group was less than that in the control group;the number of lipid droplets of hepatoma cells in HDL group was less than that in the blank control group;the number of lipid droplets of hepatoma cells in HDL group was more than that in angina pectoris group.9.Western blot was used to detect the relative expression of SRBI in each group.The results showed that,compared with the control group,the relative expression of SRBI in healthy HDL group was significantly increased(P<0.05),The relative expression of SRBI in groups of angina pectoris and myocardial infarction was less than the blank control and healthy case,and the expression of SRBI in myocardial infarction group was significantly lower than that of angina pectoris group(P<0.05).Conclusions:1.The level of Lp-PLA2 in patients with coronary heart disease was significantly higher than that in the normal control group,and the level of Lp-PLA2 was positively correlated with the severity of coronary artery disease.With the increase of Gensini score,which represents the severity of coronary heart disease,the level of Lp-PLA2 also increased.Multivariate logistic regression analysis showed that Lp-PLA2 was an independent risk factor for severe coronary heart disease.Lp-PLA2 may be an independent risk factor in patients with coronary heart disease It can cause atherosclerosis.2.HDL from normal human can increase the expression of SRBI protein of HDL receptor,which can regulate the reverse transport of cholesterol,promote the outflow of cholesterol and inhibit the process of atherosclerosis.3.HDL in patients diagnosed with coronary heart diseases inhibited the expression of SRBI in the mice liver and hepG2 cells,decreased the ability of cholesterol clearance,and inhibited the occurrence of cholesterol reversal.And as the severity of coronary heart disease increases,the loss of HDL cholesterol reverse transport function becomes more severe. |
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