Research On Correlation Of RGS2 Gene Polymorphisms And Its Protein Combined Copeptin,AngⅡ/ATIR With Preeclampsia

1.BackgroundPreeclampsia(pre-eclampsia PE)is a pregnancy-specific disease,is one of the leading causes of maternal death.There are many hypotheses about the etiology of PE,but the specific mechanisms have not yet been fully elucidated,and how to prevent and treat PE is a problem faced by obstetricians.There is a regional and racial difference in the relationship between single nucleotide polymorphisms(SNPs)and PEs.It is known that the RGS2 gene can modulate some of the vasoconstrictors,thereby lowering blood pressure.Angiotensin Ⅱ(Ang Ⅱ)and arginine vasopressin(AVP)as vasoconstrictor substances,the former and G protein coupled receptor angiotensin type Ⅰ receptor(angiotensin type Ⅰ receptor,ATIR)Combined with blood pressure after adjustment.The negative regulation of RGS2 on blood pressure may be achieved by attenuating G protein-mediated Ang Ⅱ signaling.And peptide peptide(copeptin,CPT)is a glycopeptide containing 39 amino acids,which is a product of AVP generation and release,both AVP precursor,equimolar release,considered a good AVP alternative.CPT is stable and has been used for many diseases.2.Objective and significanceThe aim of this study was to detect the SNP of the RGS2 gene and the SNP of the renin-angiotensin system(RAS)in order to find out the correlation between the RGS2 protein and the peptide in the Chinese Han population.At the same time,AngⅡ,AT1R,sFlt-1 concentration in the role of PE;for PE prediction and treatment to help.Thereby reducing the incidence of PE,reduce maternal and neonatal mortality.3.Methods3.1 Totally 132 patients with PE collected from Shenzhen Maternity and Child Healthcare Hospital,Southern Medical University during March 2015—September 2016 were recruited as case group,158 cases of healthy pregnant women were collected as the control group.SNaPshot technology was used to sequence the blood.The differences of clinical data between the two groups were analyzed.The correlation between different genotypes and preeclampsia was compared by additive model,dominant model and recessive model.3.2 A total of 50 patients with preeclampsia were selected from the above case group(FGR group 17 cases and non-FGR group 33 cases).40 healthy pregnant women were selected as the control group.Serum RGS2 Protein,Ang Ⅱ and ATIR concentration were detected.3.3 from the above cases,39 cases of preeclampsia patients were selected as the case group(E-PE group 12 cases,L-PE group 27 cases),add 11 cases of hypertensive patients with pregnancy HT group,and two control groups of similar gestational ages for both L-PE,HT groups and E-PE group(n =40,20 respectively).The plasma levels of copeptin sFlt-1 and AVP were measured by ELISA in each group in order to understanding the relationship with the severity of the disease.4.Result4.1 SNPs of RGS2 gene and RAS were compared between case group and control group4.1.1 Compared to age<35 years old pregnant woman,age ≥35 years old pregnant women occur pre-eclampsia OR = 3.88,95%CI=(1.49-10.11),P = 0.006,OR adjusted BMI was 3.54,95%CI=(1.32-9.55),P = 0.012.Pregnant women with 24≤BMI<27 compared with pregnant women with BMI<24,OR = 2.28,95%CI =(1.23-4.25),P = 0.009,adjusted age OR = 1.97,95%CI =(1.03-3.75),P = 0.039.When BMI≥27,OR = 3.68,95%CI=(1.12-12.10),P = 0.032,adjusted OR = 3.85,95%CI =(1.15-12.89),P = 0.029,the difference was statistically significant.4.1.2 The frequency of CG and GG genotype of RGS2 gene rs4606 in preeclampsia were 41.7%and 25.0%higher than those in the control group 38.2%,15.1%,while the CC genotype frequency was 33.3%lower than the control group(46.7%),(P =0.033).The frequency of G allele in preeclampsia was 45.8%higher than that in control group(34.2%),the difference was statistically significant(P = 0.005).Logistic regression analysis was used to calculate the relative risk in the additive model(GG vs CC:OR = 2.32,95%CI = 1.21-4.44,P = 0.012);in the dominant model(CG + GG vs CC:OR = 1.75(95%CI = 1.10-2.84,P = 0.022);in the recessive model(GG vs CC + CG:OR = 1.87,95%CI = 1.03-3.38,P = 0.039).4.1.3 The frequency of ID and Ⅱ genotype of rs10607564 in the preeclampsia group were 56.2%and 23.5%were significantly higher than those in the control group(41.2%and 17.0%),while the DD genotype frequency was 20.5%lower than the control group(41.8%(P = 0.001).The frequency of I allele in preeclampsia group was 51.5%higher than that in control group(37.6%),the difference was statistically significant(P = 0.001).Logistic regression analysis was used to calculate the relative risk in the additive model(ID VS DD:OR = 2.70,95%CI = 1.54-4.73,P = 0.001;Ⅱvs DD:OR = 2.69,95%CI= 1.35-5.38,P = 0.005;);in the dominant model(ID + Ⅱvs DD:OR = 2.80,95%CI = 1.64-4.76,P = 0.0001).4.1.4 The genotype and allele frequency has no significant difference between the preeclampsia group and control group in the snps of rsl764363,rs16834589,rs2746071,rs12130714,rs4646994,rs699 and rs5186.4.2 Comparison of RGS2 protein,Ang Ⅱ and ATIR between the two group4.2.1 The level of RGS2,Ang Ⅱ and AT1R in preeclampsia group were higher than the control group with the difference statistically significant(P<0.05);There are no significance of RGS2 levels between FGR group and no-FGR group(P>0.05),but higher than the control group(P<0.05);And the AngⅡ and AT1R concentration in the control group,non-FGR group and combined FGR group gradually increased,the difference was statistically significant(P<0.05).4.2.2 The crude odds ratio of RGS2,Ang Ⅱ and AT1R were RGS2(OR = 1.002;95%CI:1.001-1.002,P<0.05),AT1R(OR = 1.002;95%CI:1.001-1.003,P<0.05).After adjusting sample gestational age the OR was 1.002,1.011,1.002 respectively;and adjusting for the other two factors as confounding factors.The adjusted odds ratios were 1.001,1.001(0.993-1.009,P=0.852),1.002,There was no significant difference in Ang Ⅱ.4.2.3 Correlation analysis showed that RGS2,Ang Ⅱ and AT1R were positively correlated with the occurrence of PE,the correlation coefficient r was 0.440,0.407,0.524;the correlation coefficient with SBP was 0.417,0.406,0.536,P<0.05;and the correlation coefficient with DBP was 0.355、0.349、0.456(P<0.05);.The correlation coefficients of RGS2 protein and fetal weight were not statistically significant(P = 0.228).4.3 Analysis the correlation between copeptin,sFlt-1 and AVP levels and preeclampsia4.3.1 CPT,sFlt-1 and AVP level in HT,E-PE and L-PE group is higher than L-NT group.Moreover,the three substances level is highter than E-NT group in E-PE group.4.3.2 CPT was positively correlated with sFlt-1,AVP,age,SBP and DBP(r =0.634,0.330,0.346,0.673,0.622,P<0.01),but negatively correlated with fetal body weight and morbidity(R =-0.423,-0.375,P<0.01).5.Conclusion5.1 Maternal age over 35 years is a high risk factor for preeclampsia.Pregnant women AGE over 35 years,the risk of preeclampsia is 3.54 times higher than pregnant women within 35 years.And 95%confidence interval is(1.32-9.55).5.2 The preeclampsia risk in pregnancy women will increased with the increasing of BMI value,The risk of preeclampsia in 24 ≤ BMI<27 overweight women was 1.97 times,95%confidence interval(1.03-3.75)higher than BMI<24 pregnant women;BMI ≥ 27 obese pregnant women has 3.85 times higher risk of preeclampsia than BMI<24 pregnant women,95%confidence interval(1.15-12.89).5.3 The rs4606 and rs10607546 polymorphisms of the RGS2 gene may be associated with susceptibility to preeclampsia;the allele G of the rs4606 and the I allele of rs10607546 may be the preeclampsia susceptibility gene;which carry rs4606 CG or GG genotype and rs10607546 site ID and Ⅱ genotype of women with a increased risk to preeclampsia.5.4 Serum RGS2 protein,Ang Ⅱ and AT1R may be associated with the pathogenesis of preeclampsia,and may be related to the severity of the disease.5.5 Serum levels of CPT,sFlt-1 and AVP were elevated in serum of patients with preeclampsia.Serum CPT was positively correlated with AVP and sFlt-1.Serum CPT was expected to be used as an alternative to AVP to predict PE and its condition.