| Part Ⅰ: Relationship between coronary heart disease with lipoprotein(a)and echocardiographic calcium scoreObjective: To investigate the relationship of coronary heart disease(CHD)with lipoprotein(a)[Lp(a)] level and echocardiographic calcium score(Echo-CCS).Methods: 458 patients were chosen from department of cardiac of Tianjin chest hospital between June 2019 and May 2020.The CHD diagnosis was based on the positive results of coronary angiography.According to the degree of coronary artery disease,the CHD patients were divided into three groups.The members of control group(226 cases)who all received CTA to prove without CHD were recruited from the physical examination center during the same period.Biomarkers including Lp(a),LDL-C,HDL-C,TC,TG,GLU,CRE,apo(a)and apoB were tested.All participants received Echo-CCS assessment and were divided into two groups: without cardiac calcification(Echo-CCS=0);with cardiac calcification(Echo-CCS≥1).All participants were divided into three risk levels according to Echo-CCS and LDL-C/Lp(a)levels.Results:1.By t-test,no significant differences can be seen between the control group and the CHD group in gender,age,smoking history,diabetes history,hypertension history.Compared with the control group,the Cre,FBG,Lp(a),apo(a),apoB levels were higher in CHD group,the HDL level was lower in CHD group,there was statistically significant difference among the two groups(P<0.05).2.In the group without cardiac calcification,the number of CHD patients was lower than non-CHD.In the cardiac calcification group,CHD patients were more than nonCHD patients(P<0.05).The results of bivariate Kendall rank correlation test showed a positive correlation between Echo-CCS and the number of coronary artery lesions(r=0.364,P<0.001).3.At the Echo-CCS/Lp(a)low-risk level,the proportion of CHD patients was significantly lower than that of non-CHD patients.The proportion of CHD patients was significantly higher than that of non-CHD patients at Echo-CCS/Lp(a)medium and high risk levels(P<0.05).The results of bivariate Kendall rank correlation test showed that Echo-CCS/Lp(a)risk stratification was positively correlated with the number of coronary stenosis vessels(r=0.436,P<0.000).4.Compared with the control group,the Lp(a)level in the groups of single-vessel,double-vessel and three-vessel coronary disease was significantly higher,and the Lp(a)level in the groups of double-vessel and three-vessel coronary disease was significantly higher than that in the single-vessel coronary disease group(P<0.05).5.By Logistic regression analysis,BMI,history of diabetes,Echo-CCS/LDL-C,EchoCCS/Lp(a)are associated with the incidence of CHD and are independent risk factors for CHD.Echo-CCS/Lp(a)is more suggestive of CHD risk than the other risk factors.Conclusion: Elevated Lp(a)levels and Echo-CCS≥1 are associated with a significantly increased the risk of CHD.Echo-CCS/Lp(a)can be used as a specific screening indicator for CHD.Part Ⅱ: Correlations between LPA gene polymorphisms and calcific aortic valve disease and coronary heart diseaseObjective: To investigate the relationship between lipoprotein(a)gene(LPA)polymorphisms and calcific aortic valve disease(CAVD)and coronary heart disease in Han Chinese.Methods: A total of 248 patients were recruited(n = 101 with CAVD and n =147 with CHD)based on a diagnosis achieved using computed tomography angiography,color Doppler echocardiography,or coronary angiography.171 control individuals without CAVD or coronary atherosclerosis were also recruited.Biomarkers including levels of lipoprotein(a)[Lp(a)],low-density lipoprotein and high-density lipoprotein cholesterol,apolipoprotein A,and apolipoprotein B were tested.LPA polymorphisms rs10455872,rs6415084,rs3798221,and rs7770628 were analyzed using SNa Pshot SNP.Results:1.There were no significant difference in BMI and drinking history among the three groups(P>0.05);while significant differences were found in gender,age,smoking history,diabetes history and hypertension history among the three groups(all P<0.05).Compared with the control group,the mean age of CHD group was higher than that of the control group and CAVD group.2.Compared with the control group,the levels of LDL-C and Lp(a)were higher in CHD group and CAVD group,but the levels of apo(a)were lower(P <0.05).Compared with control group and CAVD group,CHD group had lower HDL-C and higher blood glucose(P<0.05).Compared with the control group,CHD group had higher apoB and TG(P<0.05).3.The minor allele frequencies of rs7770628(C),rs6415084(T)and rs3798221(T)were 0.147,0.126 and 0.422,respectively.There was no significant difference in the allelic frequency distribution of rs3798221,rs7770628,or rs6415084 between CHD,CAVD,and control groups.4.Lp(a)levels were significantly higher in CAVD and CHD groups compared with controls(P<0.05),but no significant difference was found in the gene distribution frequency of rs3798221,rs7770628 and rs6415084 between the control group and CAVD group or CHD group(P>0.05).5.Linear regression showed that rs3798221,rs7770628,and rs6415084 were associated with increased Lp(a)concentrations.The Lp(a)level of participants carried CT/CC minor alleles at rs7770628 was higher than that of the remainders carried TT minor alleles [β(95%CI): 0.738(0.413-1.064)].The Lp(a)level of participants carried CT/TT minor alleles at rs6415084 was higher than that of the remainders carried CC minor alleles [β(95%CI):-0.686(-1.035～-0.336)].The Lp(a)level of participants carried GG/GT minor alleles at rs3798221 was higher than that of the remainders carried TT minor alleles [β(95%CI): 0.427(0.113-0.740)].6.Two CAVD patients among the 419 participants carried AG minor alleles at rs10455872,while the remainder carried AA minor alleles,and the minor allele frequency of rs10455872(G)was 0.002.Conclusion: Rs3798221,rs6415084,and rs7770628 polymorphisms within LPA are associated with higher Lp(a)plasma levels,which correlate with increased CAVD and CHD risks.Lp(a)is an independent risk factor for the incidence of CAVD and CHD in Han Chinese in Tianjin.Part Ⅲ: The association between Lp(a),apoB,ATX,OPG,Notch1 and CAVD Objective: To investigate the possible calcific mechanism of CAVD by comparing the associations between Lp(a),apoB,ATX,OPG,Notch1 in calcific and non-calcific valves tissues.Methods: 24 cases of aortic valve specimens with aortic stenosis undergoing valve replacement surgery were collected from March 2019 to September 2020.They were divided into the CAVD group(by echocardiography indicated: trilobes of aortic valve,significantly thicken and calcific;Peak transaortic valve flow rate >4.0 m/s).A total of12 patients with normal trilobed aortic valves who underwent Bentall surgery at the same time for aortic dissection(aortic valve involvement)aneurysm were enrolled as control group.The aortic valve was normal in 7 cases without clinical or morphological abnormalities.5 cases showed mild aortic valve thicken.The general condition of the valve tissue in each group was observed.The tissue was stained with HE and the histological condition of the valve in each group was observed under light microscope.Immunohistochemical staining was performed to observe the expressions of Lp(a),apoB,ATX,OPG and Notch1,and IHC score was statistically analyzed.Western blot test was used to detect the expression levels of the above five indicators.Results:1.In the control group,the normal aortic valves were translucent,thin and flexible,and the fibers were arranged normally under microscopy without new blood vessels.Aortic valves with mild calcification are slightly thickened and slightly toughened,and myxoid degeneration can be seen under microscope.In the CAVD group,the aortic valves were thickened,and calcification of the valve was observed in different degrees.The new capillaries,hyaline degeneration,inflammatory cell infiltration,fibrosis,hyperplasia and disorder of collagen fibers,calcium salt deposition,and ossification were observed in the aortic valve under microscope.2.Immunohistochemical staining showed that: Lp(a),ATX and apoB were negatively expressed or the expression level was very low in the control group;there were moderate to strong positive expression in both non-calcific and calcific parts of CAVD group,and Lp(a),ATX and apoB showed a tendency of co-location.OPG is negative or weakly expression in the control group,there were strong positive expressions in both non-calcific and calcific parts of the CAVD group.In the control group Notch1 was strong positive expression,and in the CAVD group the Notch1 showed negative expression.The IHC score of Lp(a),apoB,ATX,OPG and Notch1 showed statistically differences(P < 0.05).3.Western blot test showed that the expressions of Lp(a),ATX and apoB were all from low to high levels in the control group and CAVD group.OPG expression was low in the control group and high in CAVD group.While Notch1 expression was high in control group,but low in CAVD group.The protein levels of the above five indicators were detected by Western blot test,and there were statistically differences between the control group and the CAVD group(P<0.05).Conclusion: Lp(a),ATX and apoB all showed mild to strong expression in normal valves and calcific stenosis valves,and they showed a co-location trend.It is suggested that Lp(a),ATX and apoB promote the occurrence of aortic valve calcification through the synergistic effect of lipid deposition.OPG is low expressed in normal valves and high expressed in calcific stenosis valves,suggesting that OPG might be the promoting factor of valve calcification.Notch1 is highly expressed in normal valves and low in calcific stenosis valves,and acts as an inhibitor of calcific stenosis. |
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