The Effect Of ABCA1in Relation To Preeclampsia And The Underlying Mechanisms

1The distribution of ABCA1gene single nucleotide polymorphisms and it’srelation to serum lipid levels of preeclampsiaObjective：Through detecting the R219K and M883I of ABCA1gene’s two singlenucleotide polymorphic sites (SNPs) in genotype, allele and haplotype frequency inpreeclampsia(PE) and normal pregnancy group, to explore the association betweenABCA1gene and PE and to reveal the role of two SNPs in PE patients’ abnormallipid metabolism.The aim of our study is to provide valuable research information inprevention, diagnosis, treatment and possible future clinical individualized therapyand gene therapy of PE.Methods：In this study,621subjects of Fujian Han population in total were recruited，consisting of305PE patients and316normal pregnant women. We detected the twosingle nucleotide polymorphic loci genotypes in Han Chinese women in FujianProvince with the method of polymerase chain reaction-restriction fragment lengthpolymorphism (PCR-RFLP) combined with agarose gel electrophoresis. We exploredthe genetic correlation between the two SNPs and PE associated with lipids and otherclinical data.The statistical analysis of data with the tools SHEsis-online software andSPSS17.0.Results：(1) The frequencies of different genotypes of the two SNPs were inagreement with Hardy-Weinberg equilibrium in our study(P>0.05)．(2) The frequency of allele K and genotype RK+KK were significantly lower inpatients with preeclampsia than in the control group patients, the differences werestatistically significant (P <0.05). The genotype and allele frequencies of M883I SNPof ABCA1gene, without significant difference between the PE group and normalpregnancy group,were statistically analysed by SPSS17.0(P>0.05).(3) Preeclampsia (mild group and severe group) serum TG, TC, LDL, ApoB, HDL, of ApoAI levels were compared with the control group, which showed significantdifferences(P <0.05).(4) We analysed the association of the ABCA1gene2SNPs and serum lipid levels,and found that the concentration of triglyceride was significantly lower in those withgenotype RK+KK than in those with genotype RR in terms of patients withpreeclampsia.The situation was the opposite of that in individuals with aconcentration of high density lipoprotein-cholesterol (HDL-C) and Apolipo proteinA1（ApoA1）; the differences were statistically significant (P<0.05). We also foundthat the concentrations of high density lipoprotein-cholesterol (HDL-C) and Apolipoprotein A1（ApoA1）were significantly higher in those with genotype MI+II than inthose with genotype MM in terms of patients with preeclampsia, the differences werestatistically significant (P<0.05).(5) We analysed the linkage disequilibrium in all the two SNPs with SHEsis software,demonstrated that there is no strong linkage disequilibrium between the two loci,therefore unable to consist the haplotype by paired SNPs.2Expression and clinical significance of ABCA1in serum and placental tissuefrom Chinese patients with preeclampsiaObjective：To investigate lipids levels and ABCA1levels of serum and placenta inpreeclampsia women; to study the relativity between hyperlipemia and ABCA1; todiscuss the effectiveness of hyperlipemia in the pathogenesis of preeclampsia; toilluminate ABCA1possibly has a significant role in the pathogenesis of the casethrough participating in lipid abnormal metabolism.Methods：52cases of preeclampsia (which include28mild preeclampsia women and24severe preeclampsia women) and30normal pregnant women which delived in thesame period were analyzed by experimentation. The lipids levels of serum weredetected by enzymic method. The ABCA1levels of serum were detected by ELISA.The mRNA or protein expression of ABCA1in placentas were detected respectivelyby RT-PCR or Western blot.Results：(1) The preeclampsia serum TG, TC, LDL concentrations were significantlyhigher than normal pregnant group, which lowering HDL levels, the differences were statistically significant (P <0.05).These women whose atherogenic index was highersignificantly were high risk people who have arteriosclerosis diseases.(2) The ABCA1levels of serum and placenta were decreased significantly in thepreeclampsia women compared to the normal pregnant women, which is related to theseverity of the disease,the differences were statistically significant (P <0.05).(3) Correlation analysis revealed that ABCA1levels of serum were positively relatedto that of placenta (r=0.384, P<0.05）, and negatively related to that of serum LDL (r=-0.279, P<0.05）,and positively related to that of serum HDL (r=0.318, P<0.05）inthe preeclampsia women.3The expression of ABCA1and OX-LDL in serum of normal Pregnancy andPreeclampsia and the effect of serum on endothelial cell dysfunction.Objective： To investigate the expression of OX-LDL and the ratio ofOX-LDL/ABCA1in serum obtained from normal pregnancy and preeclampsiawoman,and the correlation to endothelial cell dysfunction.Methods：The level of OX-LDL protein in serum samples of the study objects whichare belong to the said second part were determined by performing enzyme-linkedimmunosorbent assay(ELISA). Primary cultured human umbilical vein endothelialcells(HUVEC) were interfered with serum samples as deseribed previously.The effectof serum on endothelial cell dysfunction was determined on the basis of followingaspects:(1) monolayer barrier function was evaluated by transferringfluorescently-labeled BSA across HUVEC monolayer;(2) cell proliferation functionwas evaluated by performing methl thiazolyl tetrazolium(MTT);(3) level of secretednitric oxide(NO) was estimated by nitrate reductase assay.Results：(1) The level of OX-LDL protein in serum of preeclampsia woman wassignificantly higher than that of normal pregnancy woman,whereas the level ofABCA1protein was significantly lower.There was obvious negative correlationbetween the level of OX-LDL and ABCA1in preeclampsia（r=-0.681, P<0.05). Aboveassociated with the severity of the disease.(2) Compared to that of normal pregnaney woman,the serum of preeclampsia woman could lead to endothelial cell dysfunction,including:①high transfer of fluorescentlylabeled BSA across HUVEC monolayer indicated the damage of monolayer barrierfunction;②the proliferation ability of HUVEC was markedly decreased;③the levelof secreted NO was low as compared to that of normal pregnancy group. Aboveassociated with the severity of the disease.The differences were statisticallysignificant (P <0.05).(3) There was positive correlation between endothelial cell dysfunction and the levelof OX-LDL/ABCA1in serum of preeclampsia,the differences were statisticallysignificant (P <0.05). Above associated with the severity of the disease.In summary, based on various levels of bodies, cells and molecules, the resultsreveal that ABCA1gene and its protein plays an important role in the pathogenesis ofpreeclampsia. The possible mechanisms for this was fourfold: lipid metabolism,promote atherosclerotic sclerosis, oxidative stress, vascular endothelial cells, causinga series of preeclampsia pathological changes and clinical symptoms, for theprevention of preeclampsia, prediction, treatment and possible future individualizedtreatment and gene therapy provide valuable research data.