The Role Of NPR-C Gene A-55C Polymorphism In The Pathological Mechanism Of Hypertension

Objective:Essential hypertension is the most common cardiovascular disease that is harmful to human health.It is the result of the interaction of various environmental factors on the basis of genetic susceptibility.The pathogenesis of hypertension is complicated,and the natriuretic peptides and its receptors play an important role.Previous studies have found that NPR-C gene A-55C polymorphism exists in hypertensive patients and that affects the occurrence of hypertension,but its role in the pathological mechanism is not clear.The A-55C locus of NPR-C gene is region that is the gene expression regulatory.It is speculated that this polymorphism may affect the expression of NPR-C,which may affect the clearance of ligand ANP or affect the binding of NPR-C and its ligand with Signal pathways.To this end,this study attempts to confirm the above hypothesis by analyzing the relationship between the A-55C polymorphism of NPR-C gene in hypertensive patients and the blood pressure regulation of peripheral blood.Method:1.Research object and sample collectionAccording to the diagnostic criteria for hypertension:refer to the 2010 Guidelines for the Prevention and Treatment of Hypertension,and exclude those with secondary hypertension.The national definition of the object of the study is unclear or the information of the basic characteristics is unclear.From the physical examination,outpatient and inpatients of the First People’s Hospital of Kunming,100 cases of Yunnan Han nationality with essential hypertension were selected as the research object(the father and the mother are all Han nationality,all living in Yunnan),aged 40-80.There were 48 males and 52 females.The patients were collected fasting venous blood for the detection of NPR-C gene A-55C polymorphism,blood lipids and blood glucose and other basic indicators and NPR-C related indicators,and questionnaires were collected to collect other basic characteristics such as blood pressure,body weight and elevation.2.The automatic biochemical analyzer and its detection system of the biochemical laboratory of the First People’s Hospital of Kunming City detect the basic indicators of TC,TG,LDL,HD,LFPG,HCY and other research objects.3.PCR-RFLP detection of NPR-C gene A-55C polymorphism in the study subjects.(1)PCR amplification of the DNA fragment of the region where the A-55C site of the NPR-C gene is located.Extraction of DNA from peripheral blood of subjects by boiling lysis;the primers synthesized in the literature were used to synthesize primers,and the PCR amplification conditions and the amplification system were optimized;after optimizing the optimal amplification system and amplification conditions,100 samples of the study subjects were subjected to PCR amplification of the DNA fragment of the region where the A-55C site of the NPR-C gene was located;and the specificity of the PCR amplification product was verified by sequencing of the amplified product.(2)Detection of RFLP Polymorphism in PCR Amplified ProductsThe method of citing provides a method for the restriction enzyme digestion of the target DNA fragment amplified by PCR with the restriction endonuclease HgaI;Hgal digestion of the amplified products of 100 samples of study subjects was carried out with the optimized digestion system;The number and size of digested fragments were analyzed by electrophoresis,and the A-55C polymorphism of NPR-C gene was interpreted.4.Using imported commercial reagents for detection of ANP,NO,VEGF,ET-1 and cAMP in human serum,the indicators of 87 subjects were tested for serum ANP,NO,VEGF,ET-1 and cAMP levels.5.Data processing and analysis were performed using SPSS Statistics 16.0 statistical software package.The measurement data is normally distributed and expressed by the mean±standard deviation;the measurement data is skewed and expressed by the interquartile range.The distribution frequency of genotypes and alleles was counted and counted.Two independent sample t-test was used to compare basic clinical data among different genotypes.Rank sum test was used to test the skewed distribution of measurement data;Multiple linear regression analysis was used to analyze the relationship between blood pressure and the level of peripheral blood observation indicators,blood pressure of carriers of different genotypes and the level of peripheral blood observation indicators.The relationship between hypertension with coronary heart disease and diabetes mellitus with genotype and observation index was analyzed by Logistic regression.Statistical analysis P<0.05 for the difference was statistically significant.Result:1.100 basic characteristics of the research objectThe average level of basic characteristics of 100 subjects was as follows:age:62.64±9.01 years,BMI:25.41±3.49 kg/m2,SBP:175.62±22.44 mmHg,DBP:103.18±19.03 mmHg,FPG:5.50±1.70 mmol/L,TC:4.50±1.08 mmol/L,TG:1.32(0.91,1.70)mmol/L LDL:2.64±0.85 mmol/L,HDL:1.21±0.26 mmol/L,HCY:11.05(9.55,14.76)mmol/L.women with TC,LDL,and HDL were higher than men(P<0.05);men with HCY were higher than women(P<0.05).2.100 cases of NPR-C gene A-55C locus genotype and allele frequency distributionDetection of polymorphism of NPR-C gene A-55C locus in 100 patients with essential hypertension in Yunnan Han nationality by PCR-RFLP,AA genotype was not found;AC genotype was 25 cases with a frequency of 0.25;CC genotype was 75 cases with a frequency of 0.75.The A allele frequency is 0.125;the C allele frequency is 0.875,3.Detection results of ANP,NO,ET-1,VEGF and cAMP in peripheral blood of subjectsThe results of ANP,NO,ET-1,cAMP,VEGF levels in Peripheral blood showed that the interquartile range distribution of the five observations of 87 subjects was:ANP concentration level was 1.60(0.66,2.30)ng/mL,NO The concentration level was 9.95(4.54,21.41)umol/L,the ET-1 concentration level was 7.33(1.77,8.78)pg/mL,the VEGF concentration level was 239.45(164.59,324.61)pg/mL,and the cAMP concentration level was 32.66(18.52,68.94)pmol/mL.4.Comparison of basic characteristics of patients with different genotypesThe levels of BMI,FPG,TC,LDL,HDL and HCY in 25 patients with AC genotype were compared with those with CC genotype.The results showed that there was no significant difference in(?)basic characteristics between the two groups(P>0.05).5.Comparison of ANP,NO,ET-1,cAMP and VEGF levels among different genotype carriers in the study subjectsComparing the levels of ANP,NO,ET-1,cAMP and VEGF in peripheral blood of 22 patients with AC genotype and 65 patients with CC genotype,the results showed that the median level of NO in CC genotype carriers was higher than that in AC genotype carriers.The median level of VEGF was lower than that of AC genotype carriers,but the difference between the two groups was not statistically significant(P>0.05).6.Analysis of correlation between blood pressure and levels of ANP,NO,ET-1,cAMP and VEGF in peripheral blood of 87 subjectsThe systolic blood pressure and diastolic blood pressure were used as the dependent variables,and the concentrations of ANP,NO,ET-1,cAMP and VEGF in peripheral blood were independent variables.Multivariate linear regression analysis was performed.The results showed that there was no correlation between ANP,NO,ET-1 and systolic blood pressure(P>0.05),cAMP level was negatively correlated with systolic blood pressure(P<0.05),and VEGF level was positively correlated with systolic blood pressure(P<0.05).There was no correlation between ANP,NO,ET-1,cAMP and VEGF levels and diastolic blood pressure(P>0.05).7.Correlation between blood pressure of different genotype carriers and levels of ANP,NO,ET-1,cAMP and VEGF in peripheral blood(1)Correlation analysis between systolic blood pressure and ANP,NO,ET-1,cAMP and VEGF levels in peripheral bloodThe systolic blood pressure of patients with AC genotype and CC genotype was taken as the dependent variable,and the concentrations of ANP,NO,ET-1,cAMP and VEGF in peripheral blood were independent variables,and 22 patients with AC genotype and 65 patients with CC genotype were included.Multivariate linear regression analysis was performed.The results showed that there was no correlation between the systolic blood pressure and ANP,VEGF and AC genotype carriers in the patients with AC genotype(P>0.05).The levels of cAMP and ET-1 were negatively correlated with systolic blood pressure(P<0.05).There was a positive correlation between NO level and systolic blood pressure(P<0.05).There was no correlation between ANP,NO and ET-1 levels and systolic blood pressure in patients with CC genotype(P>0.05).There was a negative correlation between cAMP level and systolic blood pressure(P<0.05),and VEGF level was positively correlated with systolic blood pressure.(P<0.05).(2)Correlation between diastolic blood pressure and ANP,NO,ET-1,cAMP and VEGF levels in peripheral bloodThe diastolic blood pressure of patients with AC genotype and CC genotype was taken as the dependent variable,and the concentrations of ANP,NO,ET-1,cAMP and VEGF in peripheral blood were independent variables,and 22 patients with AC genotype and 65 patients with CC genotype were included.Multivariate linear regression analysis was performed.The results showed that there was no correlation between the diastolic blood pressure and ANP,ET-1,cAMP,VEGF and AC genotype carriers in the patients with AC genotype(P>0.05).There was a positive correlation between NO level and diastolic blood pressure(P<0.05).There were no correlations between the peripheral blood levels of CC genotypes and the diastolic blood pressure of CC genotype carriers(P>0.05).8.Analysis of influencing factors of essential hypertension complications(1)Analysis of influencing factors of coronary heart disease in patients with essential hypertensionThe value of essential hypertension combined with coronary heart disease was 1 and the value of non-hypertension with coronary heart disease was 0,Logistic multivariate regression analysis was performed with genotypes of NPR-C A-55C locus and ANP,NO,ET-1,cAMP,VEGF,SBP,TG and LDL in peripheral blood as independent variables.The results showed that TG,LDL,ANP,NO,CC genotypes were associated with coronary heart disease(P<0.05).(2)Analysis of influencing factors of diabetes in patients with essential hypertensionThe value of essential hypertension with diabetes was 1 and the score of non-combined diabetes was 0.The NPR-C gene A-55C genotype and ANP,NO,ET-1,cAMP and VEGF levels in peripheral blood were independent variables were analyzed by logistic multivariate regression analysis.No statistically significant factors were found in the results(P>0.05).Conclusion:1.The polymorphism distribution of NPR-C gene A-55C locus in the Yunnan Han patients with essential hypertension was mainly CC genotype,and AA genotype was not found.CC genotype is associated with susceptibility to hypertension.2.NPR-C gene A-55C polymorphism may affect the levels of NO and VEGF in peripheral blood of patients with essential hypertension in Yunnan Han nationality3.In the Yunnan Han patients with essential hypertension,the NPR-C gene A-55C gene polymorphism may affect the level of cAMP and the levels of effector molecules NO,ET-1 and VEGF in ANP or CNP/NPR-C signaling pathway.In turn,it affects the blood pressure regulation of ANP or CNP/NPR-C signaling pathways,but may not affect NPR-C clearance of ANP.4.In the Yunnan Han patients with essential hypertension,NPR-C gene A-55C gene polymorphism may affect coronary heart disease in patients with essential hypertension,and ANP and NO may increase the risk of coronary heart disease in patients.