angiotensinogen and Pre-Eclampsia

The aetiological mechanism of preeclampsia (PE) is unclear exactly, so we attempted to investigate the association between susceptibility to preeclampsia and renin-angiotensin-aldosterone system (RAAS) gene polymorphisms to explore the aetiology in terms of genetics. A systematic search was performed in electronic databases to identify relevant studies. Eventually 73 studies were enrolled, odds ratios were generated by 5 genetic models. In overall analysis, significant associations were detected for AGT M235T, AT1R A1166C and CYP11B2 C344T whereas negative correlation was shown for AGT T174M. As stratified by race and geography, AGT 235T allele and AT1R 1166C allele increased preeclampsia risk and AGT T174M was justified uncorrelated with preeclampsia. Our meta-analysis illustrated that AGT 235T allele and AT1R 1166C allele increased and CYP11B2 344T allele decreased preeclampsia risk while AGT T174M polymorphism did not change preeclampsia risk. Hence, pregnant women carrying high-risk genotypes need strengthened management to prevent and early identification of preeclampsia.

Topics: Angiotensinogen; Cytochrome P-450 CYP11B2; Female; Genetic Predisposition to Disease; Genotype; Humans; Polymorphism, Genetic; Pre-Eclampsia; Pregnancy; Renin-Angiotensin System

Pregnancy demands major cardiovascular, renal and endocrine changes to provide an adequate blood supply for the growing fetus. The renin-angiotensin-aldosterone system plays a key role in this adaptation process. One of its components, prorenin, is released in significant amounts from the ovary and uteroplacental unit. This review describes the sources of prorenin in the periconception period and in pregnancy, including its modulation by in-vitro fertilization protocols, and discusses its potential effects, among others focusing on preeclampsia. It ends with discussing the long-term consequences, even in later life, of inappropriate renin-angiotensin-aldosterone system activity in pregnancy and offers directions for future research. Ultimately, a full understanding of the role of prorenin periconceptionally and during pregnancy will help to develop tools to diagnose and/or prevent reproductive complications.

Topics: Angiotensin I; Angiotensinogen; Female; Fertilization in Vitro; Gene Expression Regulation; Humans; Ovary; Placenta; Pre-Eclampsia; Pregnancy; Renin; Renin-Angiotensin System; Signal Transduction; Uterus

The compensatory alterations in the rennin-angiotensin-aldosterone system (RAAS) contribute to the salt-water balance and sufficient placental perfusion for the subsequent well-being of the mother and fetus during normal pregnancy and is characterized by an increase in almost all the components of RAAS. Preeclampsia, however, breaks homeostasis and leads to a disturbance of this delicate equilibrium in RAAS both for circulation and the uteroplacental unit. Despite being a major cause for maternal and neonatal morbidity and mortality, the pathogenesis of preeclampsia remains elusive, where RAAS has been long considered to be involved. Epidemiological studies have indicated that preeclampsia is a multifactorial disease with a strong familial predisposition regardless of variations in ethnic, socioeconomic, and geographic features. The heritable allelic variations, especially the genetic polymorphisms in RAAS, could be the foundation for the genetics of preeclampsia and hence are related to the development of preeclampsia. Furthermore, at a posttranscriptional level, miRNA can interact with the targeted site within the 3'-UTR of the RAAS gene and thereby might participate in the regulation of RAAS and the pathology of preeclampsia. In this review, we discuss the recent achievements of genetic polymorphisms, as well as the interactions between maternal and fetal genotypes, and miRNA posttranscriptional regulation associated with RAAS in preeclampsia. The results are controversial but utterly inspiring and attractive in terms of potential prognostic significance. Although many studies suggest positive associations with genetic mutations and increased risk for preeclampsia, more meticulously designed large-scale investigations are needed to avoid the interference from different variations.

Topics: Aldosterone; Angiotensinogen; Female; Gene Expression Regulation; Humans; MicroRNAs; Mutation; Peptidyl-Dipeptidase A; Polymorphism, Genetic; Pre-Eclampsia; Pregnancy; Receptor, Angiotensin, Type 1; Renin; Renin-Angiotensin System

Preeclampsia a hypertensive disorder of pregnancy that mainly manifests as high blood pressure and proteinuria. Angiotensinogen (AGT) plays important roles in the regulation of blood pressure. The purpose of this study was to investigate the relationship between AGT M235T polymorphism and risk of preeclampsia using a meta-analysis.. In this meta-analysis, 22 studies were selected by searching PubMed, EMBASE, ISI and CNKI databases up to October 2011. Crude odds ratios with corresponding 95% confidence intervals were used to evaluate the association between the AGT M235T polymorphism and risk of preeclampsia. Subgroup analyses were conducted by ethnicity and parity.. The TT genotype of the AGT M235T polymorphism was associated with elevated risk of preeclampsia in the overall analysis. In subgroup analysis according to ethnicity, increased risks were also found in Caucasians. After stratification based on parity, the excess risk was found in multigravida.. These results showed that the TT genotype may play critical roles in the development of preeclampsia.

Topics: Amino Acid Substitution; Angiotensinogen; Ethnicity; Female; Genetic Association Studies; Genetic Heterogeneity; Genetic Predisposition to Disease; Humans; Polymorphism, Single Nucleotide; Pre-Eclampsia; Pregnancy; Publication Bias; Risk Factors

There are controversies in reports on the association of the angiotensinogen (AGT) gene polymorphisms with the risk of developing pre-eclampsia (PE). We performed a meta-analysis to examine the association between the AGT polymorphisms and PE risk: M235T (31 studies involving 2555 patients and 6114 controls) and T174M (six studies involving 681 patients and 2076 controls). For the M235T polymorphism, the TT genotype increased the PE risk as compared to the MM genotype (odds ratio 1.61, 95% confidence intervals 1.22-2.14, P= 0.001). When stratified by ethnicity, the TT genotype remained significantly associated with higher PE risk in Caucasians and Mongolians but not in Africans. Similar results were also obtained under all three genetic models of the M235T polymorphism. For the T174M polymorphism, no significant association was found in the comparisons (MT vs. TT and MM vs. TT) and under any genetic models. The analysis excluding the highly significant Hardy-Weinberg equilibrium-violating studies and sensitivity analysis further strengthened the validity of these associations. No publication bias was observed in this study. This meta-analysis demonstrates that the AGT M235T polymorphism is significantly associated with PE whereas the T174M polymorphism is not.

Topics: Angiotensinogen; Female; Genetic Predisposition to Disease; Humans; Polymorphism, Genetic; Pre-Eclampsia; Pregnancy; Risk Factors

The angiotensinogen gene M235T polymorphism is related to an increased risk of hypertension. Hypertension and pregnancy-induced hypertension have been suggested to share common etiologic factors. We examined whether this mutation also increases the risk of preeclampsia/eclampsia.. Pubmed/Medline, Web of Science and EMBASE were searched and a hand search of bibliographies was conducted. In all, 17 studies (including 1446 cases and 3829 controls) published in English between 1993 and October 2006 on the association of angiotensinogen gene M235T polymorphism with preeclampsia/eclampsia were selected.. The overall odds ratio (OR) under a random effects model revealed that individuals homozygous for the T allele were 1.62 times more likely to develop preeclampsia/eclampsia [95% confidence interval (CI), 1.12 to 2.33; P = 0.01) compared to individuals homozygous for the M allele. The relation in Caucasians (OR = 1.99; 95% CI, 1.18-3.36; P = 0.01) was similar to that in East Asian populations (OR = 1.74; 95% CI, 0.92-3.28; P = 0.09), although the latter was not statistically significant due to lower numbers of studies. Under additive, recessive and dominant genetic models positive associations were also found. A meta-regression analysis showed that ethnic background was a significant source of between-study heterogeneity (P = 0.04) but design of the study, study size and Hardy-Weinberg equilibrium deviation were not. There was a low probability of publication bias.. Our meta-analysis expands the findings on hypertension by showing that the presence of the T allele of the angiotensinogen gene is associated with an increased risk to develop preeclampsia/eclampsia.

Topics: Angiotensinogen; Eclampsia; Female; Genetic Predisposition to Disease; Humans; Hypertension, Pregnancy-Induced; Polymorphism, Genetic; Pre-Eclampsia; Pregnancy; Regression Analysis

There are controversies in reports on the association of polymorphisms in endothelial nitric oxide synthase, angiotensinogen, angiotensin receptor type 1 and angiotensin-converting enzyme genes with an increased risk of developing preeclampsia. We performed a systematic search of published case-control studies through the PubMed database up to January 2006, and report the results of a meta-analysis of polymorphisms investigated in more than five studies: Glu298Asp in eNOS gene (9 analyses involving 1055 patients and 1788 controls), Met235Thr in AGT gene (13 analyses involving 1128 patients and 2278 controls), and intron 16 insertion-deletion polymorphism in ACE gene (10 analyses involving 1121 patients and 1361 controls). Statistically significant associations with preeclampsia were identified for the Met235Thr/AGT polymorphism: OR 1.65 (95% CI 1.19, 2.29) if the polymorphism is considered under the dominant genetic model, and OR 1.54 (95% CI 1.12, 2.11) under the recessive model. For insertion-deletion/ACE polymorphism, statistical significance was demonstrated when the polymorphism was considered under the recessive model: OR 1.51 (95% CI 1.17, 1.94). No single polymorphism was identified as having a major effect.

Topics: Adult; Angiotensinogen; Case-Control Studies; Female; Genetic Predisposition to Disease; Humans; Nitric Oxide Synthase Type III; Peptidyl-Dipeptidase A; Polymorphism, Genetic; Pre-Eclampsia; Pregnancy; Receptor, Angiotensin, Type 1; Risk Factors

Population studies have been suggesting genetic predisposition to the appearance of preeclampsia (PE) for a considerable period of time now. In familial occurrence of the disease higher frequency of preeclampsia has been observed in mothers, daughters and sisters of women burned of this poor medical history and higher risk to severe PE development. Although a single gene may contribute to the development of the patomechanizm of PE, most authors focus on the analysis of the common influence of candidate genes which are involved in a series of pathophysiological processes of PE. Thus, PE is often believed to be the final phenotype (increase of blood pressure and multiorgan complications development), being the result of intermediate phenotypes acting at the same time and being modulated by environmental factors. PE belongs to the complex human disease. The results of the findings connected with the contribution of maternal, paternal and fetal genotypes in PE development remain unclear, though a stronger influence of maternal genes, with a weaker influence of those transferred from the father, may be observed. Despite the existing divergences (the findings on the genetic background of PE are in conflict, no doubt due to the population differences and small number of investigated groups), the results obtained so far stress the necessity to discover the genetic risk factors as it may do both: facilitate the identification of groups of women predisposed to preeclampsia and allow for an early prophylactic administration.

Topics: Angiotensinogen; Female; Genetic Predisposition to Disease; Humans; Models, Genetic; Pre-Eclampsia; Pregnancy; Receptors, Angiotensin; Women's Health

Despite recent efforts to identify susceptibility genes of preeclampsia, the genetic determinants of the condition remain ill-defined, as is the situation for most disorders of complex inheritance patterns. The angiotensinogen, factor V, and methylenetetrahydrofolate reductase genes have been investigated in different populations, as have other genes involved in blood pressure, vascular volume control, thrombophilia, lipid metabolism, oxidative stress, and endothelial dysfunction. The study of the genetics of complex traits is faced with both methodological and genetic issues; these include adequate sample size to allow for the identification of modest genetic effects, of gene-gene and gene-environment interactions, the study of adequate quantitative traits and extreme phenotypes, haplotype analyses, statistical genetics, genome-wide (hypothesis-free) versus candidate-gene (hypothesis-driven) approaches, and the validation of positive associations. The use of genetically well-characterized populations showing a founder effect, such as the French-Canadian population of Quebec, in genetic association studies, may help to unravel the susceptibility genes of disorders showing complex inheritance, such as preeclampsia. It is necessary to better evaluate the role of the fetal genome in the resulting predisposition to preeclampsia and its complications. Eventually, we may be able to integrate genetic information to better identify the women at risk of developing preeclampsia, and to improve the management of those suffering from this condition.

Topics: Adult; Angiotensinogen; Factor V; Female; Genetic Predisposition to Disease; Humans; Methylenetetrahydrofolate Reductase (NADPH2); Oxidoreductases Acting on CH-NH Group Donors; Pre-Eclampsia; Pregnancy

There is general consensus that genetic variation accounts in part for individual susceptibilities to essential hypertension. In marked contrast to classic mendelian disorders, in which genetic alterations produce a gain or loss of function, genetic determinants of essential hypertension, high blood pressure of unknown cause, are expected to be small, achieving significance through the cumulative effects of environmental exposure over the course of a lifetime. Whether and how genetic factors that contribute to common diseases can be identified remain unclear. Research on a link between angiotensinogen and essential hypertension illustrates a path that began in genetics and is now leading toward nephrology. Various challenges encountered along the way may prove to be characteristic features of genetic investigations of the pathogenesis of common diseases. The implication of a gene by statistical analysis is only the beginning of a protracted process of functional analysis at increasing levels of biologic integration. The ultimate goal is to develop an understanding of the manner in which genetic variation at a locus can affect a physiologic parameter and to extract from this inference new knowledge of significance for the prevention or treatment of disease.

Topics: Alleles; Angiotensin II; Angiotensinogen; Female; Genetic Linkage; Genetic Variation; Haplotypes; Homeostasis; Humans; Hypertension; Japan; Male; Models, Genetic; Nephrons; Polymorphism, Genetic; Pre-Eclampsia; Pregnancy; Pregnancy Complications, Cardiovascular; Promoter Regions, Genetic; Renin-Angiotensin System

Essential hypertension is a complex disease influenced by different genetic and environmental factors. The renin-angiotensin system (RAS) is implicated in blood pressure regulation. Angiotensinogen (AGT) is the precursor of the biologically active angiotensin II (Ang II). Initial studies on hypertensive siblings and case-control studies indicated the important role of the angiotensinogen gene (AGT) for the predisposition to essential hypertension, preeclampsia and obesity-related hypertension. Recently, different AGT polymorphisms had been identified and analyzed in case-control studies. The aim of present studies is the analysis of potentially functional AGT variants (C-532T, G-6A), which might be responsible for the regulation of gene expression and therefore AGT generation. The A-6 allele is in complete linkage disequilibrium with the T235 allele and is associated with higher AGT expression in vitro. Segregation linkage analysis demonstrated that the C-532T polymorphism influences plasma AGT variability more significantly than the G-6A variant. Since the C-532T polymorphism is located within a AP-2 consensus element, functional promoter analyses are required. The understanding of the molecular basis of RAS in essential hypertension may provide us with new and more specific pharmacological agents and perhaps the ability to individualize antihypertensive treatment.

Topics: Alleles; Angiotensinogen; Case-Control Studies; Female; Genetic Predisposition to Disease; Humans; Hypertension; Linkage Disequilibrium; Obesity; Polymorphism, Genetic; Pre-Eclampsia; Pregnancy

Pre-eclampsia is a major cause of maternal and foetal morbidity and mortality but the etiology and pathogenesis are basically unknown. Pre-eclampsia is clearly associated to the placenta (trophoblast) alone. Epidemiological observations have raised one of the most popular hypotheses of the genesis of pre-eclampsia--an immune maladaptation between mother and foetus. Markedly raised incidences are seen in blood relatives (mothers, sisters, daughters) to pre-eclamptic women. In the genetic studies, the importance of specific combinations of mother-foetus-genotypes are recognized. The pathological processes involve an aberrant trophoblast-invasion of the spiral arteries, placental dysfunction, abnormal levels of cytokines and endothelial cell dysfunction, resulting in systemic and organ dysfunction. Genetic linkage studies and the use of molecular biology will probably elucidate the predisposing factors, etiology and pathogenesis of pre-eclampsia in more detail. There might be several pathways ending up with the same clinical manifestations.

Topics: Angiotensinogen; Cytokines; Female; Genetic Markers; Genetic Predisposition to Disease; Humans; Nitric Oxide; Pre-Eclampsia; Pregnancy

Topics: Angiotensinogen; Female; Genetic Predisposition to Disease; HLA Antigens; Humans; Mitochondria; Nitric Oxide Synthase; Peptidyl-Dipeptidase A; Pre-Eclampsia; Pregnancy; Receptors, Angiotensin; Renin-Angiotensin System

Preeclampsia is familial. Pedigree analyses suggest that one or more common alleles may act as "preeclampsia susceptibility genes." The authors speculate that genes involved in blood pressure control, volume regulation, placental health, vascular disease, and vascular remodeling, underlie familial susceptibility to preeclampsia. Several candidate genes have been examined. These data suggest that a common mutation in the angiotensinogen promoter, A(-6), leads to elevated expression of this gene and pleiotropic effects, including abnormal spiral artery remodeling and failed hypervolemia of pregnancy. The factor V Leiden mutation, which predisposes women to thromboembolic disorders during pregnancy, has been implicated as another preeclampsia susceptibility gene. New insights into the genetics of preeclampsia will contribute to the understanding of this disease and should ultimately lead to improved diagnosis and treatment.

Topics: Angiotensinogen; Factor V; Female; Humans; Kidney; Placenta; Pre-Eclampsia; Pregnancy; Uterus

It is most unlikely that there is a single 'pre-eclampsia (PE) gene'. We are probably looking for a cluster of polymorphisms which, possibly in conjunction with environmental factors, predispose to the development of the condition. Accurate phenotyping is vital for any genetic studies of PE, and since the disease is only clinically-detectable in the second half of pregnancy, is particularly difficult. It is increasingly likely that there is a fetal genetic contribution which can only be examined after birth. Candidate genes examined on the basis of displayed or hypothetical pathophysiological effects, but for which no evidence of association or linkage has been found have included HLA-DRbeta, HLA-G, and tumour necrosis factor alpha (chromosome 6), angiotensin-converting enzyme (chromosome 17) and CuZn superoxide dismutase (chromosome 21). Chromosomal exclusion mapping and a pedigree study suggest a role for genes on chromosomes 1, 3, 4, 9 or 18. Two genes concerned with clotting, those for factor 5 and methylenetetrahydrofolate reductase, lie on chromosome 1. Both have polymorphisms present in significantly higher frequency in women with PE, as well as showing functional abnormality. They probably predispose to the development of the condition, without being necessary for it. The angiotensinogen (Aogen) gene also lies on chromosome 1. The renin-angiotensin system may be activated during the early stages of PE and subsequently suppressed. In some populations, a relatively common polymorphism is present in raised frequency in women with PE, but it is also raised in non-pregnant hypertensive subjects. However, it is in partial linkage disequilibrium with another polymorphism which shows significantly distorted transmission from mother to fetus in PE pregnancies. Furthermore, its expression is significantly raised in the decidual spiral arteries; abnormal placentation is a feature of PE. We have also shown that a relatively common polymorphism in the angiotensin AT1 receptor gene (chromosome 3) is associated with raised density of the receptor. Thus far, studies of candidate genes have been on a small scale and have very much reflected the pathophysiological research interests of the investigators. The multifaceted nature of PE and the difficulties of accurate phenotyping require the accumulation of a large, very carefully phenotyped, database. It is hoped that funding will become available this year in the UK to allow the collection of such a database. The i

Topics: Angiotensinogen; Chromosomes, Human, Pair 1; Factor V; Female; Humans; Methylenetetrahydrofolate Reductase (NADPH2); Mutation; Oxidoreductases Acting on CH-NH Group Donors; Pre-Eclampsia; Pregnancy; Receptor, Angiotensin, Type 1; Receptor, Angiotensin, Type 2; Receptors, Angiotensin

Topics: Angiotensinogen; Calcium; Endothelins; Epoprostenol; Female; Humans; Lipids; Lupus Coagulation Inhibitor; Nitric Oxide; Nitrous Oxide; Pre-Eclampsia; Pregnancy; Renin-Angiotensin System

On the basis of recent advances in molecular biology and statistical genetics, it has become possible to search for chromosome regions that contain genes predisposing to hypertension and to directly link specific mutations on candidate genes to hypertension. As the human genome has been extensively mapped, highly informative, polymorphic markers are available, which can be used to detect genes in their proximity with 'hypertensinogenic' alleles. Some of these markers have been shown to be tightly linked to the genes of the renin-angiotensin system. Furthermore, the coding and regulatory regions of the genes encoding for renin, ACE, angiotensinogen and the AT1 receptor have been partially characterized. This provides a basis for further definition of specific polymorphisms within these genes that are of functional importance and that can be used to examine their contribution to the inheritance of primary hypertension. The first studies of these links have already emerged and have been reviewed in this article. Several problems arise in performing such linkage studies in human primary hypertension, however. It is difficult to define the genetic background of heterogeneous, multigenetic and multifactorial diseases such as human hypertension. Extensive studies of population genetics, including the analysis of large numbers of generations and controlled breeding experiments, cannot be performed, for obvious reasons. Blood pressure is not a convenient study trait, because it exhibits great intraindividual variance and also because of the relatively low reliability of just a few indirect measurements obtained under loosely controlled environmental conditions. Twenty-four-hour ambulatory blood pressure measurements may improve such investigations in the near future. Ravogli et al (1990) reported that the 24-hour ambulatory systolic blood pressure is higher in normotensive subjects of hypertensive parents than in normotensive subjects of normotensive parents--a finding that had not been previously reported using the conventional method of measurement. Hypertension as a trait per se is also problematic: its classification (above 140/90 mmHg) is purely artefactual, and its aetiology is highly heterogeneous. Thus, we have to keep in mind that even strong gene effects, if present in only a small subgroup of hypertensives, may not be detected in these studies. Attempts are being made to strengthen the analysis by characterizing physiologically distinct subgroups. In ad

Topics: Angiotensin II; Angiotensinogen; Female; Humans; Hypertension; Hypertrophy, Left Ventricular; Myocardial Infarction; Peptidyl-Dipeptidase A; Pre-Eclampsia; Pregnancy; Receptors, Angiotensin; Renin; Renin-Angiotensin System

This study evaluated urinary angiotensinogen in preeclampsia.. Normal pregnant (n = 57) and preeclamptic patients (n = 31); Normal pregnant (n = 10) and preeclamptic rats (n = 10) were studied. Urinary angiotensinogen and plasma angiotensin II were assayed by enzyme-linked immunosorbent assay (ELISA).. Urinary angiotensinogen in preeclampsia patients (2.0 ± 1.1 ng/mg creatinine) was suppressed (*p < 0.05) compared to normal pregnant (2.7 ± 1.5 ng/mg creatinine). Plasma angiotensin II in preeclampsia patients (preeclampsia: 36.2 ± 7; normal pregnant: 48.1 ± 5 fmol/mL) was lower. The similar result was observed in preeclampsia rat model.. The reduced urinary excretion of angiotensinogen was both in human preeclampsia patients and rat model of preeclampsia.

Topics: Adult; Angiotensinogen; Animals; Biomarkers; Case-Control Studies; Enzyme-Linked Immunosorbent Assay; Female; Humans; Pre-Eclampsia; Pregnancy; Rats; ROC Curve

Preeclampsia (PE) is a pregnancy-specific multisystemic syndrome. This study aimed to investigate the associations between angiotensinogen (AGT), methylenetetrahydrofolate reductase (MTHFR), vascular endothelial growth factor (VEGF) polymorphisms, and PE in the Han Chinese population.. We genotyped 26 single-nucleotide polymorphisms (SNP) in three genes by using QuantStudio™ 12 K Flex Real-Time PCR technology in 168 patients with PE and 204 healthy pregnant control subjects. The associations of tested polymorphisms with PE were analyzed at allele, genotype, and haplotype levels.. A common coding variant in MTHFR, rs2274976, was significantly associated with increased risk of PE in both allelic and genotype models (P < 0.05). The heterozygous genotypes of rs699 (G/A vs G/G) in AGT gene and rs3025035 (C/T vs C/C) in VEGF gene showed weak associations with increased PE risk, whereas the mutant homozygous genotype of rs3024987 (TT vs C/C) and the heterozygous genotype of rs3025039 (C/T vs C/C) in VEGF gene displayed weak associations with decreased PE risk (P < 0.05).. However, these weak associations lost significance after multiple testing correction. The results indicated that rs2274976 in MTHFR gene may contribute to the increased risk of PE in pregnant women. AGT and VEGF gene polymorphisms may not play a significant role in PE development.

Topics: Adult; Angiotensinogen; Asian People; Case-Control Studies; Female; Genetic Predisposition to Disease; Humans; Methylenetetrahydrofolate Reductase (NADPH2); Polymorphism, Genetic; Pre-Eclampsia; Pregnancy; Vascular Endothelial Growth Factor A

The aim: To study the distribution and influence of coagulation factor gene polymorphisms, endothelial dysfunction, blood pressure regulator on the development of obstetric and perinatal complications in women with preeclampsia (PE).. Materials and methods: The prospective cohort study included 46 women with PE and maternal or fetal complications and 87 pregnant women with PE, without complications. Genetic polymorphisms of coagulation factors and fibrinolysis (1691 G→A FVL, 20210 G→A prothrombin, 675 5G/4G PAI-1, 455 G→A fibrinogen β), endothelial dysfunction (192 Q→R PON-1, 677 C→T MTHFR) and blood pressure regulator (235 M→T angiotensinogen II) were studied with the help of allele-specific polymerase chain reaction.. Results: Markers of predisposition to the development of obstetric and perinatal complications in pregnant women with PE are the following genotypes: 1691 GA by V Leiden factor gene - increases the risk in 2.9 times (95% CI 1.94-4.33), 20210 GA by prothrombin gene - in 2.36 times (95% CI 1.54-3.6), 20210 AA by prothrombin gene - in 3.12 times (95% CI 2.4-4.0). Pathological polymorphisms in the genes of angiotensinogen II 235 M→T, PAI-1 5G/4G, fibrinogen β 455 G→A, paraoxonase-1 192 Q→R do not significantly affect the development of complications during preeclampsia.. Conclusions: The development of PE against the background of the existence of acquired and hereditary types of thrombophilia is associated with a more severe course, early-onset and the development of life-threatening complications for a mother and fetus.

Topics: Angiotensinogen; Factor V; Female; Fibrinogen; Humans; Placenta; Plasminogen Activator Inhibitor 1; Pre-Eclampsia; Pregnancy; Pregnant Women; Prospective Studies; Prothrombin; Thrombophilia

Topics: Adult; Alleles; Angiotensinogen; Blood Pressure; Case-Control Studies; Female; Genetic Predisposition to Disease; Genotype; Humans; Polymorphism, Genetic; Pre-Eclampsia; Pregnancy; Risk Factors; Thailand; Young Adult

The oxidation status of angiotensinogen (AGT) may have a critical role in pre-eclampsia. We used a validated, quantitative, mass spectrometry-based method to measure the oxidized and total AGT levels in plasma of pre-eclamptic women (n = 17), normotensive-matched controls (n = 17), and healthy non-pregnant women (n = 10). Measurements of plasma glutathione peroxidase (GPx) activity and serum selenium concentrations were performed as markers of circulating antioxidant capacity. Higher proportions of oxidized AGT in plasma from pre-eclamptic women compared to matched normotensive pregnant controls (P = 0.006), whilst maintaining a similar total plasma AGT concentration were found. In the pre-eclamptic group, blood pressure were correlated with the proportion of oxidized AGT; no such correlation was seen in the normotensive pregnant women. Plasma GPx was inversely correlated with oxidized AGT, and there was an inverse association between serum selenium concentration and the proportion of oxidized AGT. This is the first time that oxidized AGT in human plasma has been linked directly to antioxidant status, providing a mechanism for the enhanced oxidative stress in pre-eclampsia. We now provide pathophysiological evidence that the conversion of the reduced form of AGT to its more active oxidized form is associated with inadequate antioxidant status and could indeed contribute to the hypertension of pre-eclampsia.

Topics: Adult; Angiotensinogen; Antioxidants; Biomarkers; Blood Pressure; Female; Glutathione Peroxidase; Humans; Oxidation-Reduction; Oxidative Stress; Pilot Projects; Placenta; Pre-Eclampsia; Pregnancy; Selenium

Topics: Angiotensinogen; Animals; Disease Models, Animal; Female; Pre-Eclampsia; Pregnancy; Rats; Rats, Sprague-Dawley; Rats, Transgenic; RNA Interference

This study sought to identify potential bioactive peptides from the placenta that are involved in preeclampsia (PE) to obtain information about the prediction, diagnosis and treatment of PE. The liquid chromatography/mass spectrometry was used to perform a comparative analysis of placental peptides in normal and PE pregnancies. Gene ontology (GO), pathway analysis and ingenuity pathway analysis (IPA) were used to evaluate the underlying biological function of the differential peptides based on their protein precursors. Transwell assays and qPCR were used to study the effect of the identified bioactive peptides on the function of HTR-8/SVneo cells. A total of 392 upregulated peptides and 420 downregulated peptides were identified (absolute fold change ≥ 2 and adjusted P value < 0.05). The GO analysis, pathway analysis, and IPA revealed that these differentially expressed peptides play a role in PE. In addition, the up-regulated peptide "DQSATALHFLGRVANPLSTA" derived from Angiotensinogen exhibited effect on the invasiveness of HTR-8/SVneo cells. The current preliminary research not only provides a new research direction for studying the pathogenesis of PE, but also brings new insights for the prediction, diagnosis and treatment of PE.

Topics: Adult; Angiotensinogen; Cell Movement; Chromatography, Liquid; Female; Gene Expression Profiling; Gene Expression Regulation; Humans; MicroRNAs; Peptides; Placenta; Polymerase Chain Reaction; Pre-Eclampsia; Pregnancy; Tandem Mass Spectrometry; Trophoblasts; Up-Regulation; Young Adult

Some data suggest an association between the single nucleotide polymorphisms AGT T704C, ACE I/D, and AT1R A1166C and preeclampsia, but overall, the data are conflicting; the aim of our study was to discover a more stable and reliable association between these polymorphisms and PE risk.. A comprehensive literature search for this meta-analysis was conducted. Odds ratios (OR) and 95% confidence intervals (CIs) were calculated to evaluate the strength, and heterogeneity test was conducted. Trial sequential analysis was also performed.. A total of forty studies were finally included in our meta-analysis. The AGT T704C polymorphism was associated with PE risk in three genetic models (dominant OR = 1.33, 95%CI = 1.12-1.59; heterozygote OR = 1.26, 95%CI = 1.05-1.52; homozygote OR = 1.44, 95%CI = 1.14-1.83). No heterogeneity was observed in the three genetic models for the ACE I/D polymorphism. For subgroup analysis by geography, no significant association was detected. Significant associations were observed in mixed race, early-onset, late-onset, and more than 200 subgroups for the AT1R A1166C polymorphism; however, only one study was analyzed in these subgroups.. Our results indicated the AGT T704C and ACE I/D polymorphisms were associated with an increased risk of PE. Increased risks were also observed for the two polymorphisms in subgroups including Asians, Europeans, Caucasoid, and Mongoloid. Moreover, an increased PE risk with the ACE I/D polymorphism in the severe PE population was also detected. Regarding the AT1R A1166C polymorphism, weak associations were observed, but further studies are required.

Topics: Angiotensinogen; Female; Genetic Predisposition to Disease; Humans; Meta-Analysis as Topic; Peptidyl-Dipeptidase A; Polymorphism, Single Nucleotide; Pre-Eclampsia; Pregnancy; Receptor, Angiotensin, Type 1; Renin-Angiotensin System; Risk Factors

Changes in the renin-angiotensin-aldosterone system's (RAAS) activity due to different genetic variations could represent risk factors for the onset of preeclampsia.. To test and quantify the relationships of 8 RAAS gene polymorphisms (angiotensinogen (AGT)-M235T, AGT-T174M, angiotensin converting enzyme (ACE)-I/D, ACE8-A2350G, angiotensin II type 1 receptor (AGTR1)-A1166C, angiotensin II type 2 receptor (AGTR2)-C3123A, renin (REN)-G83A, aldosterone synthase (CYP11B2)-T344C) with susceptibility to early- (EOPE) and late-onset preeclampsia (LOPE).. We performed polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP) analysis in 217 pregnant women, of whom 87 pregnant women with EOPE/LOPE and 130 normal pregnant women. The relationship between the studied RASS gene polymorphisms and EOPE/LOPE was tested by multiple logistic regressions.. The multivariate logistic regression analysis showed that AGT-M235T (adjusted OR = 4.63), AGT-T174M (adjusted OR = 4.13), REN-G83A (adjusted OR = 3) and CYP11B2-C344T (adjusted OR = 3.13) gene polymorphisms remained independent risk factors for EOPE. Moreover, ACE-I/D (adjusted OR = 4.04), ACE-A2350G (adjusted OR = 3.5), AGTR1-A1166C (adjusted OR = 2.73), and REN-G83A (adjusted OR = 2.67) polymorphisms remained independent risk factors for LOPE. The frequency of overweight was significantly different (p = 0.001) in pregnant women with EOPE, LOPE and the control group (LOPE:16, 29.6% vs. EOPE:12, 36.4% vs. control group:16, 12.3%). Pregnant women with EOPE had babies with a significantly lower mean birth weight (2067.9 ± 887.9) in comparison to women with LOPE (mean ± SD: 2860.1 ± 771.1, p < 0.001) and women with normal pregnancies, respectively (mean ± SD: 3324.9 ± 484.9, p < 0.001).. We confirmed the influence of the renin-angiotensin-aldosterone system through these 8 genetic variations on the onset of preeclampsia.

Topics: Adult; Angiotensinogen; Case-Control Studies; Female; Genetic Predisposition to Disease; Humans; Placenta; Polymerase Chain Reaction; Polymorphism, Genetic; Polymorphism, Restriction Fragment Length; Pre-Eclampsia; Pregnancy; Prenatal Care; Renin-Angiotensin System; Risk Factors; Romania; White People

Angiotensinogen mediates an important role in the pathophysiology of preeclampsia, a disorder of pregnancy characterized by hypertension and proteinuria usually after 20 weeks of gestation. Angiotensinogen is found in two distinct posttranslational forms in the plasma, an oxidized and a reduced (free thiol) form. Higher levels of the oxidized form are associated with an increased risk of preeclampsia. We have developed novel ELISA assays to quantitate the levels of total and free thiol angiotensinogen allowing for calculation of the amount of oxidized angiotensinogen species. We describe the methodology for performing these assays.

Topics: Angiotensinogen; Enzyme-Linked Immunosorbent Assay; Female; Humans; Hypertension; Oxidation-Reduction; Pre-Eclampsia; Pregnancy; Prognosis

Preeclampsia (PE) is a life-threatening complication of pregnancy that accounts for 12% of all maternal deaths worldwide. The aim of this study is to investigate the relationships between the polymorphisms of angiotensinogen (AGT) gene and preeclampsia.. In this study, 240 unrelated preeclampsia patients and 178 normotensive women were examined. Genomic DNA was extracted then we assessed M235T(C/T) and A-6G polymorphisms of the AGT gene. Genotyping of M235T and A-6G polymorphisms were performed using SSP-PCR and MS-PCR, respectively.. A significant protective association was observed between A-6G G allele, A-6G A/G heterozygote genotype (OR = 0.6, p = 0.007 and OR = 0.6, p = 0.04) against PE. Furthermore, it was shown that two copies of A-6G A allele would increase PE risk (OR: 0.62, p = 0.04). Our results did not show a significant association for M235T polymorphism and PE. However, the combinations of A-6G A/A genotype and M235T T/C genotype (OR = 0.4, p = 0.02) and also A-6G A/G genotype and M235T T/C genotype (OR = 0.5, p = 0.04) in controls represented a significant protective association against PE.. According to the existence of significant correlation between two candidate polymorphisms, A-6G and M235T polymorphisms, with PE disease in our study, they may be considered as valuable factors in susceptibility to PE disease in Iranian women.

Topics: Adolescent; Adult; Alleles; Amino Acid Substitution; Angiotensinogen; Case-Control Studies; Female; Genetic Association Studies; Genetic Predisposition to Disease; Genotype; Humans; Inheritance Patterns; Iran; Odds Ratio; Polymorphism, Single Nucleotide; Pre-Eclampsia; Pregnancy; Risk Assessment; Risk Factors; Young Adult

Background AGT (angiotensinogen) synthesis occurs in renal proximal tubular epithelial cells, independent from systemic AGT , as a component of the intrarenal renin-angiotensin system. We investigated urinary AGT , as a biomarker for renin-angiotensin system activation, and electrolyte concentrations, in relation to glomerular volume, as a proxy for glomerular endotheliosis in renal biopsy tissue from pregnant normotensive control and hypertensive women. Methods and Results Urine samples were collected from normotensive control (n=10), gestational hypertensive (n=6), and pre-eclamptic (n=16) women at the time a renal biopsy was obtained. Samples were collected from Lund University Hospital between November 1999 and June 2001. Urinary AGT , potassium, and sodium were measured, normalized to urinary creatinine. Mean glomerular volume was estimated from biopsy sections. AGT protein expression and localization were assessed in renal biopsies by immunohistochemistry. Urinary AGT concentrations were higher in hypertensive pregnancies (median, gestational hypertension: 11.3 ng/mmol [interquartile range: 2.8-13.6]; preeclampsia: 8.4 ng/mmol [interquartile range: 4.2-29.1]; normotensive control: 0.6 ng/mmol [interquartile range: 0.4-0.8]; P<0.0001) and showed a positive relationship with estimated mean glomerular volume. Urinary potassium strongly correlated with urinary AGT ( P<0.0001). Although numbers were small, AGT protein was found in both glomeruli and proximal tubules in normotensive control but was present only in proximal tubules in women with hypertensive pregnancy. Conclusions This study shows that pregnant women with gestational hypertension or preeclampsia have increased urinary AGT and potassium excretion associated with signs of glomerular swelling. Our data suggest that the kidneys of women with hypertensive pregnancies and endotheliosis have inappropriate intrarenal renin-angiotensin system activation, which may contribute toward the pathogenesis of hypertension and renal injury.

Topics: Adult; Angiotensinogen; Biopsy; Case-Control Studies; Edema; Female; Humans; Hypertension, Pregnancy-Induced; Immunohistochemistry; Kidney Glomerulus; Kidney Tubules, Proximal; Potassium; Pre-Eclampsia; Pregnancy; Renin-Angiotensin System; Sodium

Black ethnicity is associated with worse pregnancy outcomes in women with chronic hypertension. Preexisting endothelial and renal dysfunction and poor placentation may contribute, but pathophysiological mechanisms underpinning increased risk are poorly understood. This cohort study aimed to investigate the relationship between ethnicity, superimposed preeclampsia, and longitudinal changes in markers of endothelial, renal, and placental dysfunction in women with chronic hypertension. Plasma concentrations of placental growth factor (PlGF), syndecan-1, renin, and aldosterone and urinary angiotensinogen-to-creatinine ratio (AGTCR), protein-to-creatinine ratio (PCR), and albumin-to-creatinine ratio (ACR) were quantified during pregnancy and postpartum in women with chronic hypertension. Comparisons of longitudinal biomarker concentrations were made using log-transformation and random effects logistic regression allowing for gestation. Of 117 women, superimposed preeclampsia was diagnosed in 21% ( n = 25), with 24% ( n = 6) having an additional diagnosis of diabetes. The cohort included 63 (54%) women who self-identified as being of black ethnicity. PlGF concentrations were 67% lower [95% confidence interval (CI) -79 to -48%] and AGTCR, PCR, and ACR were higher over gestation, in women with subsequent superimposed preeclampsia (compared with those without superimposed preeclampsia). PlGF <100 pg/ml at 20-23.9 wk of gestation predicted subsequent birth weight <3rd percentile with 88% sensitivity (95% CI 47-100%) and 83% specificity (95% CI 70-92%). Black women had 43% lower renin (95% CI -58 to -23%) and 41% lower aldosterone (95%CI -45 to -15%) concentrations over gestation. Changes in placental (PlGF) and renal (AGTCR/PCR/ACR) biomarkers predated adverse pregnancy outcome. Ethnic variation in the renin-angiotensin-aldosterone system exists in women with chronic hypertension in pregnancy and may be important in treatment selection.

Topics: Adult; Angiotensinogen; Biomarkers; Black People; Chronic Disease; Creatinine; Endothelium, Vascular; England; Female; Humans; Hypertension, Pregnancy-Induced; Kidney; Longitudinal Studies; Placenta; Placenta Growth Factor; Pre-Eclampsia; Pregnancy; Prognosis; Randomized Controlled Trials as Topic; Risk Factors; Serum Albumin, Human; Time Factors

Are any microRNAs (miRNAs) that target the placental renin-angiotensin system (RAS) in the human placenta suppressed in early gestation?. Overall, 21 miRNAs with predicted RAS mRNA targets were less abundant in early versus term placentae and nine were more highly expressed.. Regulation of human placental RAS expression could alter placental development and therefore normal pregnancy outcome. The expression of genes encoding prorenin (REN), angiotensinogen, (pro)renin receptor, angiotensin converting enzyme 2, and the angiotensin II type 1 receptor are highest in early gestation, at a time when oxygen tension is at its lowest. Studies have shown that the human placental RAS is sensitive to oxygen, as are some miRNAs that regulate RAS mRNAs. We propose that in early pregnancy, the prevailing low O2 tension, by suppression of levels of miRNAs that target RAS mRNAs, results in increased expression of RAS mRNAs and encoded proteins. As gestation proceeds and the prevailing oxygen tension rises, abundance of these miRNAs increases, and placental RAS mRNA expression is suppressed.. The expression of miRNAs was compared in human placentae collected in early (10-11 weeks; n = 7) and mid-gestation (14-18 weeks; n = 8) with placenta collected at term (38-40 weeks; n = 8). Expression of placental miRNAs in women with early (29-35.1 weeks; n = 8) or late-onset pre-eclampsia (PE) (>34-weeks gestation; n = 8) and gestational age matched preterm (31.6-35.1 weeks; n = 8) and term normotensive controls were also compared.. Agilent Human miRNA microarray v19 was used to detect up to 2006 miRNAs in four placentae from each group. Statistically different levels of expression were determined and refined using predictive modelling. Placental miRNAs predicted to target RAS mRNAs were identified in three databases. Differences detected on the array were confirmed for some miRNAs by semi-quantitative RT-PCR (qPCR, n = 7-8 for all groups). Two differentially expressed miRNAs that were known to target human renal REN mRNA (miR-181a-5p and miR-663) were transfected into human HTR-8/SVneo trophoblast cells to examine their effect on placental REN expression and prorenin levels.. In early gestation placentae, 186 miRNAs were differentially expressed compared with term placentae (109 increased, 77 decreased). Thirty of the differentially expressed miRNAs were predicted to target RAS components. In mid-gestation placentae, 117 miRNAs were differentially expressed compared with term placentae (69 increased, 48 decreased). Of these, 19 had RAS mRNAs as predicted targets. Eight miRNAs that were lower in early gestation and predicted to target RAS mRNAs were confirmed by qPCR. All showed an increase during gestation and could influence the transgestational profile of the human placental RAS. Additionally, on the array, three miRNAs predicted to target RAS mRNAs (miR-892c-3p, miR-378c and miR-514b-3p) were overexpressed in placentae from women with late-onset PE (P = 3.6E-10, P = 1.8E-05, P = 5.3E-06; respectively). miR-663, which suppresses renal REN mRNA expression, was overexpressed in early-onset PE placentae as determined by qRT-PCR analysis (P = 0.014). Transfection of miR-181a-5p and miR-663 into HTR-8/SVneo trophoblast cells suppressed REN mRNA expression (P = 0.05) and prorenin protein production (P = 0.001).. Data can be found via GEO accession number GSE109832.. Further validation that the differentially expressed miRNAs do indeed directly target RAS mRNAs and affect placental development and function is required. This study is limited by the small sample size. Therefore independent validation in a larger cohort is required.. We propose that suppression of miRNAs that target the placental RAS in early gestation is partly responsible for the increase in RAS expression at this time, in order to promote placental development. Later in pregnancy, we have detected overexpression of several miRNAs in placentae from women with PE. These may prove to be biomarkers for early detection of women at risk of developing PE. Since the placenta produces at least two miRNAs that were found in the kidney to target REN mRNA, and that also target placental REN mRNA, the escape of these miRNAs into the maternal circulation in excess amounts could affect maternal renal REN mRNA production and thereby disturb maternal fluid and electrolyte homoeostasis.. This work was supported by the National Health and Medical Research Council, Australia (APP1043537). K.G.P. is supported by an Australian Research Council Future Fellowship (FT150100179). C.T.R. is supported by a Lloyd Cox Professorial Research Fellowship from the University of Adelaide. F.Z.M. is supported by a National Heart Foundation Future Leader Fellowship and Baker Heart and Diabetes Institute Fellowship. The authors declare that they have no competing interests.

Topics: Angiotensinogen; Blotting, Western; Enzyme-Linked Immunosorbent Assay; Female; Humans; MicroRNAs; Placenta; Pre-Eclampsia; Pregnancy; Receptor, Angiotensin, Type 1; Renin-Angiotensin System; Trophoblasts

To investigate the association of the gene polymorphisms of: angiotensinogen (AGT), renin (REN), angiotensin II receptor 1 (AT1R) and angiotensin II receptor 2 (AT2R), in the pathogenesis of PE in South African Black women.. 603 pregnant women; 246 normotensive and 357 with PE (early-onset=187, late-onset=170), were recruited. Each study group was subdivided into HIV infected and uninfected groups. The distribution and frequencies of gene polymorphisms of AGT (M235T), REN (C-5312T), AT1R (A1166C) and AT2R (C3123A) were determined in purified DNA by Real Time Polymerase Chain Reaction.. The distribution of T allele and TT genotype of AGT in PE were significantly higher than the normotensive group (95% vs 91%, OR 1.9, 95%CI 1.2-3.1, p=0.0051; 90% vs 83%, OR 1.84, 95%CI 1.11-3.05, p=0.01) respectively. The distributions of genotypes of REN, AT1R and AT2R were similar in PE and normotensive groups.. The T allele of AGT may play a role in the pathogenesis of PE. The genotypes of REN, AT1R and AT2R were not associated with the development of PE.

Topics: Adult; Alleles; Angiotensinogen; Black People; Female; Gene Frequency; Genetic Predisposition to Disease; Genotype; Humans; Polymorphism, Single Nucleotide; Pre-Eclampsia; Pregnancy; Receptor, Angiotensin, Type 1; Receptor, Angiotensin, Type 2; Renin; Renin-Angiotensin System; South Africa

Using a transgenic cross, we evaluated features of preeclampsia, renal injury and the sFlt1/VEGF changes. Transgenic hAGT and hREN, or wild-type (WT) C57Bl/6 mice were cross-bred: female hAGT × male hREN for preeclampsia (PRE) model and female WT × male WT for pregnant controls (WTP). Samples were collected for plasma VEGF, sFlt1, and urine albumin. Blood pressures (BP) were monitored by telemetry. Vascular reactivity was investigated by wire myography. Kidneys and placenta were immunostained for sFlt1 and VEGF. Eleven PRE and 9 WTP mice were compared. PRE more frequently demonstrated albuminuria, glomerular endotheliosis (80% vs. 11%;

Topics: Albuminuria; Angiotensinogen; Animals; Blood Pressure; Disease Models, Animal; Endothelial Cells; Female; Genetic Predisposition to Disease; Gestational Age; Humans; Kidney Diseases; Kidney Glomerulus; Mice, Inbred C57BL; Mice, Transgenic; Phenotype; Placenta; Pre-Eclampsia; Pregnancy; Renin; Renin-Angiotensin System; Signal Transduction; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factor Receptor-1; Vascular Remodeling; Vasoconstriction; Vasodilation

A functioning placental renin-angiotensin system (RAS) appears necessary for uncomplicated pregnancy and is present during placentation, which occurs under low oxygen tensions. Placental RAS is increased in pre-eclampsia (PE), characterised by placental dysfunction and elevated oxidative stress. We investigated the effect of high altitude hypoxia on the RAS and hypoxia-inducible factors (HIFs) by measuring mRNA and protein expression in term placentae from normotensive (NT) and PE women who delivered at sea level or above 3100 m, using an explant model of hypoxia-reoxygenation to assess the impact of acute oxidative stress on the RAS and HIFs. Protein levels of prorenin (P = 0.049), prorenin receptor (PRR; P = 0.0004), and angiotensin type 1 receptor (AT1R, P = 0.006) and type 2 receptor (AT2R, P = 0.002) were all significantly higher in placentae from NT women at altitude, despite mRNA expression being unaffected. However, mRNA expression of all RAS components was significantly lower in PE at altitude than at sea level, yet PRR, angiotensinogen (AGT) and AT1R proteins were all increased. The increase in transcript and protein expression of all the HIFs and NADPH oxidase 4 seen in PE compared to NT at sea level was blunted at high altitude. Experimentally induced oxidative stress stimulated AGT mRNA (P = 0.04) and protein (P = 0.025). AT1R (r = 0.77, P < 0.001) and AT2R (r = 0.81, P < 0.001) mRNA both significantly correlated with HIF-1β, whilst AT2R also correlated with HIF-1α (r = 0.512, P < 0.013). Our observations suggest that the placental RAS is responsive to changes in tissue oxygenation: this could be important in the interplay between reactive oxygen species as cell-signalling molecules for angiogenesis and hence placental development and function.

Topics: Altitude; Angiotensinogen; Case-Control Studies; Female; Fetal Hypoxia; Humans; Hypoxia-Inducible Factor 1; NADPH Oxidases; Oxidative Stress; Placenta; Pre-Eclampsia; Pregnancy; Receptors, Angiotensin; Renin; Renin-Angiotensin System; RNA, Messenger

A history of placenta-mediated pregnancy complications (PMPCs) increases the risk of cardiovascular disease later in life, possibly related to the persistence of endothelial dysfunction. We performed this study in order to search for a common genetic background shared by women with a history of PMPC and vascular disorders, due to their common pathophysiologic pathway of endothelial dysfunction.. We analyzed the prevalence of seven polymorphisms in ACE, AGTR1, AGT, and eNOS genes, endothelial-function related, in 290 women with a history of premature cardiovascular events (CVDs), and in 367 women with a history of PMPC (preeclampsia (PE), stillbirth (SB), and small for gestational age (SGA)), compared with 300 healthy women (HW) who delivered after uneventful pregnancy (HW).. ACE D allele frequency was similar between women with history of CVD and PMPC, and significantly higher than that observed in HW [OR (95% CI) 1.91, p = 0.002, and OR (95% CI) 2.18, p < 0.0001, respectively]. In women carrying ACE-240T or eNOS-786C allele, a two-fold increase in SB susceptibility was evidenced (p = 0.004 and p = 0.005, respectively). Women with a history of SB and premature CVD exhibited a significantly higher unfavorable allelic burden ≥ 3 in comparison to that observed in HW (p < 0.0001 and p = 0.002, respectively).. Our findings demonstrate a common genetic background shared by women with a history of vascular disorders and PMPCs; pregnancy may be considered a window to future cardiovascular risk; therefore, "non-classic" genetic biomarkers of endothelial dysfunction might allow one to identify women who could have a greater benefit for an early cardiovascular screening and prevention.

Topics: Alleles; Angiotensinogen; Cardiovascular Diseases; Female; Gene Frequency; Genetic Predisposition to Disease; Genotype; Humans; Infant, Small for Gestational Age; Nitric Oxide Synthase Type III; Peptidyl-Dipeptidase A; Pre-Eclampsia; Pregnancy; Pregnancy Complications; Receptor, Angiotensin, Type 1; Risk Factors; Stillbirth

To analyze methylation profiles of known preeclampsia/eclampsia (PE) candidate genes in normal (NL) and preeclamptic (PE) women at delivery.. A matched case-control study comparing methylation in 79 CpG sites/33 genes from an independent gene set in maternal leukocyte DNA in PE and NL (n = 14 each) on an Illumina BeadChip platform. Replication performed on second cohort (PE = 12; NL = 32).. PE demonstrates differential methylation in POMC, AGT, CALCA, and DDAH1 compared with NL.. Differential methylation in four genes associated with PE may represent a potential biomarker or an epigenetic pathophysiologic mechanism altering gene transcription.

Topics: Adult; Amidohydrolases; Angiotensinogen; Calcitonin Gene-Related Peptide; Case-Control Studies; CpG Islands; DNA Methylation; Eclampsia; Female; Gene Expression Profiling; Humans; Leukocytes; Parturition; Pre-Eclampsia; Pregnancy; Pro-Opiomelanocortin; Young Adult

Maternal vitamin D deficiency is proposed as a risk factor for preeclampsia in humans. We tested the hypothesis that vitamin D depletion aggravates and high supplementation ameliorates the preeclampsia phenotype in an established transgenic rat model of human renin-angiotensin system-mediated preeclampsia. Adult rat dams, transgenic for human angiotensinogen (hAGT) and mated with male rats transgenic for human renin (hREN), were fed either vitamin D-depleted chow (VDd) or enriched chow (VDh) 2 weeks before mating and during pregnancy. Mean blood pressure was recorded by tail-cuff, and 24-hour urine samples were collected in metabolic cages at days 6 and 18 of gestation. Rats were sacrificed at day 21 of gestation. Depleted dams (VDd) had negligible serum 25-hydroxyvitamin D2+3 levels (mean ± SEM; 2.95 ± 0.45 nmol/l vs. VDh 26.20 ± 2.88 nmol/l, P = .01), but in both groups, levels of 1,25(OH)2D3 remained below detection level of 25 pmol/l. Dietary vitamin D depletion did not aggravate hypertension (mean ± SEM BP, day 20 of gestation: 151.38 ± 5.65 mmHg VDd vs. 152.00 ± 4.10 mmHg VDh) or proteinuria. Fetal anthropometrics were similar between the groups, whereas VDd displayed lower placental:fetal weight ratios (0.15 vs. 0.16 g/g, P = .01) and increased sFlt-1/PlGF ratio. Expression of hREN was lower in placenta of VDd dams (0.82 ± 0.44 AU vs. 1.52 ± 0.15 AU, P = .04). Expression of key vitamin D metabolizing enzymes was unchanged. Dietary vitamin D intervention did not alter key aspects of the preeclampsia phenotype using the transgenic rodent model of human renin-angiotensin system-mediated pre-eclampsia, plausibly due to altered vitamin D metabolism or excretion in the transgenic rats.

Topics: Adult; Angiotensinogen; Animals; Blood Pressure Determination; Diet; Disease Models, Animal; Female; Humans; Male; Phenotype; Placenta; Pre-Eclampsia; Pregnancy; Proteinuria; Rats; Rats, Sprague-Dawley; Rats, Transgenic; Renal Elimination; Renin; Renin-Angiotensin System; Risk Factors; Vitamin D; Vitamin D Deficiency

Uterine natural killer cells are important for uteroplacental development and pregnancy maintenance. Their role in pregnancy disorders, such as preeclampsia, is unknown. We reduced the number of natural killer cells by administering rabbit anti-asialo GM1 antiserum in an established rat preeclamptic model (female human angiotensinogen×male human renin) and evaluated the effects at the end of pregnancy (day 21), compared with preeclamptic control rats receiving normal rabbit serum. In 100% of the antiserum-treated, preeclamptic rats (7/7), we observed highly degenerated vessel cross sections in the mesometrial triangle at the end of pregnancy. This maternal uterine vasculopathy was characterized by a total absence of nucleated/living cells in the vessel wall and perivascularly and prominent presence of fibrosis. Furthermore, there were no endovascular trophoblast cells within the vessel lumen. In the control, normal rabbit serum-treated, preeclamptic rats, only 20% (1/5) of the animals displayed such vasculopathy. We confirmed the results in healthy pregnant wild-type rats: after anti-asialo GM1 treatment, 67% of maternal rats displayed vasculopathy at the end of pregnancy compared with 0% in rabbit serum-treated control rats. This vasculopathy was associated with a significantly lower fetal weight in wild-type rats and deterioration of fetal brain/liver weight ratio in preeclamptic rats. Anti-asialo GM1 application had no influence on maternal hypertension and albuminuria during pregnancy. Our results show a new role of natural killer cells during hypertensive pregnancy in maintaining vascular integrity. In normotensive pregnancy, this integrity seems important for fetal growth.

Topics: Analysis of Variance; Angiotensinogen; Animals; Cell Movement; Female; Fetal Development; Gestational Age; Interleukin-15; Killer Cells, Natural; Placental Circulation; Pre-Eclampsia; Pregnancy; Pregnancy, Animal; Rats; Rats, Sprague-Dawley; Statistics, Nonparametric; Trophoblasts

Pregnancy-induced hypertension (PIH, including preeclampsia [PE] and gestational hypertension [GH]) and cardiovascular diseases (CVDs) have some metabolic changes and risk factors in common. Many studies have reported associations between single nucleotide polymorphisms (SNPs) of renin-angiotensin-aldosterone system (RAAS) genes and CVDs (particularly hypertension), and their findings have provided candidate SNPs for research on genetic correlates of PIH. We explored the association between hypertension-related RAAS SNPs and PIH in a Chinese population. A total of 130 cases with PE, 67 cases with GH, and 316 controls were recruited. Six candidate SNPs of the RAAS system were selected. Multiple logistic regression analysis adjusting for maternal age, fetal sex, and gestational diabetes mellitus showed significant associations between angiotensinogen (AGT) rs3789678 T/C and GH (p = 0.0088) and between angiotensin II receptor type 1 (AGTR1) rs275645 G/A and PE (p = 0.0082). The study population was further stratified by maternal age (<30 and ≥30 years), and stratified and crossover analyses were conducted to determine genetic associations in different age groups. Our findings suggest that the impacts of different SNPs might be affected by maternal age; however, the effect of this potential gene-age interaction on PIH needs further exploration.

Topics: Adult; Angiotensinogen; Asian People; Case-Control Studies; Female; Genetic Predisposition to Disease; Humans; Hypertension, Pregnancy-Induced; Male; Maternal Age; Peptidyl-Dipeptidase A; Polymorphism, Single Nucleotide; Pre-Eclampsia; Pregnancy; Receptor, Angiotensin, Type 1; Renin-Angiotensin System

Preeclampsia is a life-threatening disorder of pregnancy. The pathogenic mechanisms of preeclampsia remain uncertain. The aim of this study is to investigate the relation between urinary angiotensinogen (UAGT) levels, an indicator of local renin-angiotensin system (RAS) activity in the kidney, and blood pressure and urinary protein excretion in preeclampsia.. For this study, 90 women aged between 20-39 years were recruited. Spot urine samples were collected to measure urinary angiotensinogen/creatinine ratio (UAGT/UCre). Log(UAGT/UCre) was compared in pregnancies with and without preeclampsia and non-pregnant controls. Factors affecting log(UAGT/UCre) in pregnancies were also investigated.. In all pregnancies log(UAGT/UCre) levels were significantly higher than in non-pregnant controls (0.58±0.19 vs. 0.33±0.14, respectively, p=0.002). However, log(UAGT/UCre) levels in pregnancies with preeclampsia were slightly lower than in normal pregnancies (0.52±0.18 vs. 0.64±0.19, respectively, p=0.012). Log(UAGT/UCre) levels were correlated positively with blood pressure and proteinuria in pregnancies with preeclampsia. However, log(UAGT/UCre) levels were not correlated with age, height, body weight, gestational age, body mass index, and serum creatinine.. This study showed that elevated local RAS activity in kidney was correlated with high blood pressure and proteinuria in preeclampsia. Local RAS activation in the kidneys may be one of the contributing factors in the development of preeclampsia.

Topics: Adult; Angiotensinogen; Blood Pressure; Creatinine; Demography; Female; Humans; Hypertension; Pre-Eclampsia; Pregnancy; Proteinuria; Systole; Young Adult

Preeclampsia is a major cause of maternal and perinatal mortality and morbidity. Regardless of susceptibility or predisposing conditions and risk factors, the degree of increase in abdominal pressure is directly related to the severity of preeclampsia, particularly in women with hydatidiform mole. When increased abdominal pressure is normalized by delivery, preeclampsia is cured. Recent genetic studies highlighted two leading risk factors for preeclampsia: chronic renal disease and T235 homozygosity for the AGT gene. Thus, while there is increased abdominal pressure in pregnancy, an imbalanced renin angiotensin system and renal injuries lead to a vicious cycle of increasing abdominal pressure and further renal injuries. A hypothesis for the potential participation of pressure in preeclampsia is described and the amelioration of preeclampsia through postural intervention and the possible therapeutic effect of angiotensin is suggested.

Topics: Abdomen; Angiotensinogen; Angiotensins; Female; Humans; Models, Biological; Posture; Pre-Eclampsia; Pregnancy; Pressure; Renal Insufficiency, Chronic; Risk Factors

Angiotensinogen exists in two distinct redox forms in plasma, the oxidized sulfhydryl-bridge form and the reduced, unbridged, free thiol form. The oxidized form of angiotensinogen compared to the free thiol form preferentially interacts with renin resulting in increased generation of angiotensin. The predictive potential of the ratio of free-thiol to oxidized angiotensinogen in the plasma for pre-eclampsia was first suggested by the Read group in ref 10. We propose an improved method for determining the ratio and validate the method in a larger cohort of pregnant women.. Plasma samples from 115 individuals with pre-eclampsia and from 55 healthy pregnant control subjects were collected sequentially over a 2 year period. Using two distinct enzyme-linked immunosorbent assays (ELISAs) the plasma levels of total and free thiol angiotensinogen were quantified. The oxidized angiotensinogen plasma level is derived by subtracting the level of free thiol, reduced angiotensinogen from the total angiotensinogen levels in the plasma.. The relative proportion of free thiol angiotensinogen, expressed as a percentage of that observed with an in-house standard, is significantly decreased in pre-eclamptic patients (70.85% ± 29.49%) (mean ± SD) as compared to healthy pregnant controls (92.98 ± 24.93%) (mean ± SD) p ≤ 0.0001. The levels of total angiotensinogen did not differ between the two groups.. Patients with pre-eclampsia had substantially lower levels of free thiol angiotensinogen compared to healthy pregnant controls, whilst maintaining similar total angiotensinogen levels in the plasma. Hence, elevated levels of plasma oxidized angiotensinogen may be a contributing factor to hypertension in the setting of pre-eclampsia.

Topics: Adult; Angiotensinogen; Biological Assay; Biomarkers; Case-Control Studies; Enzyme-Linked Immunosorbent Assay; Female; Humans; Oxidation-Reduction; Oxidative Stress; Pre-Eclampsia; Pregnancy; ROC Curve

The pregnant female human angiotensinogen (hAGN) transgenic rat mated with the male human renin (hREN) transgenic rat is a model of preeclampsia (TgA) with increased blood pressure, proteinuria, and placenta alterations of edema and necrosis at late gestation. We studied vascular responses and the role of COX-derived prostanoids in the uterine artery (UA) at early gestation in this model. TgA UA showed lower stretch response, similar smooth muscle α-actin content, and lower collagen content compared with Sprague-Dawley (SD) UA. Vasodilation to acetylcholine was similar in SD and TgA UA (64 ± 8 vs. 75 ± 6% of relaxation, P > 0.05), with an acetylcholine-induced contraction in TgA UA that was abolished by preincubation with indomethacin (78 ± 6 vs. 83 ± 11%, P > 0.05). No differences in the contraction to phenylephrine were observed (159 ± 11 vs. 134 ± 12 %KMAX, P > 0.05), although in TgA UA this response was greatly affected by preincubation with indomethacin (179 ± 16 vs. 134 ± 9 %KMAX, P < 0.05, pD2 5.92 ± 0.08 vs. 5.85 ± 0.03, P < 0.05). Endothelium-independent vasodilation was lower in TgA UA (92 ± 2 vs. 74 ± 5% preconstricted tone, P < 0.05), and preincubation with indomethacin restored the response to normal values (90 ± 3 vs. 84 ± 3%). Immunostaining showed similar signals for α-actin, COX-2, and eNOS between groups (P > 0.05). Plasma thromboxane levels were similar between groups. In summary, TgA UA displays functional alterations at early gestation before the preeclamptic phenotype is established. Inhibition of COX enzymes normalizes some of the functional defects in the TgA UA. An increased role for COX-derived prostanoids in this model of preeclampsia may contribute to the development of a hypertensive pregnancy.

Topics: Angiotensinogen; Animals; Disease Models, Animal; Female; Humans; Male; Phenotype; Pre-Eclampsia; Pregnancy; Rats; Rats, Sprague-Dawley; Rats, Transgenic; Renin; Uterine Artery

The aim of this study was to evaluate possible associations of genetic polymorphisms predisposing to cardiovascular disease with the development and/or the severity of preeclampsia.. A two hospital-based prospective case-control study was performed in Germany and Ghana. 470 blood samples of 250 Caucasian and 220 black African have been genotyped by pyrosequencing and fragment length analysis. We evaluated the distribution of the epoxide hydrolase 1 (EPHX1) polymorphism on exon 3, the endothelial nitric oxide synthase (eNOS) polymorphisms on exon 7 and on intron 4, the angiotensinogen polymorphism on exon 2 and the estrogen receptor 1 polymorphism in intron 1.. 74 Caucasian and 84 African were classified as preeclampsia with 27 Caucasian developing a hemolysis, elevated liver enzymes and low platelets (HELLP) syndrome and 17 African women experiencing eclampsia. Multivariate logistic regression analysis adjusting for ethnicity, age and parity revealed for carriers of eNOSI4 VNTR4a a 1.7-fold increased (95% CI 1.10-2.711, p = 0.016) risk to develop preeclampsia and a 3.6-fold increase for carriers of the EPHX1 113Tyr (95% CI 1.366-8.750, p = 0.009) to develop severest preeclampsia.. Our finding of eNOSI4 polymorphism predisposing to preeclampsia independently of ethnicity, age and parity supports the concept of NO being involved in the endothelial disorder preeclampsia. Since EPHX1 is highly expressed in the liver, can interact with various signaling pathways and is involved in central nervous system disorders, the association of EPHX1 polymorphism with the HELLP syndrome and eclampsia may hint to EPHX being a further key player in the pathogenesis of preeclampsia.

Topics: Adult; Angiotensinogen; Black People; Case-Control Studies; Epoxide Hydrolases; Estrogen Receptor alpha; Exons; Female; Genotype; Germany; Ghana; Humans; Introns; Nitric Oxide Synthase Type III; Polymorphism, Genetic; Pre-Eclampsia; Pregnancy; Prospective Studies; White People

The rate-limiting step of the renin-angiotensin system is the enzymatic cleavage of angiotensinogen (AGT) by renin. The aims of the present study were to investigate the association between AGT T704C (M235T) and -217 G→A polymorphisms with the risk of preeclampsia and synergistic effects of both polymorphisms on the susceptibility to preeclampsia.. We studied AGT variants in 170 women with preeclampsia, including 84 women with mild and 86 women with severe forms of preeclampsia, and 100 age and parity matched controls.. There was a trend towards increased risk of severe preeclampsia in the presence of -217 AA (odds ratio (OR)=1.5, 95% confidence interval (CI)= 0.38-5.84, p=0.57) and TC+CC genotypes (OR=1.32, 95% CI= 0.67-2.58, p=0.42). However, the interaction of both alleles of -217A and 704C highly increased the risk of severe preeclampsia, by 2.23-fold, although this did not reach statistical significance. The frequency of the CC genotype of the T704C polymorphism in early-onset preeclampsia tended to be higher (35%) compared with that in patients with late-onset preeclampsia (21.7%).. The present study demonstrates that both variants of AGT -217 G→A and T704C might work in synergism to influence the risk of severe preeclampsia, which needs to be confirmed in studies with larger sample size.

Topics: Adult; Angiotensinogen; Female; Genetic Variation; Genotype; Humans; Polymorphism, Genetic; Pre-Eclampsia; Pregnancy; Risk

We studied phenotypes of the circulating renin-angiotensin-aldosterone system and circadian BP during preeclampsia depending on polymorphism of angiotensinogen gene M235T. The TT genotype or T allele of angiotensinogen M235T gene polymorphism is associated with the risk of preeclampsia. Plasma renin activity significantly decreases under conditions of preeclampsia. The TT genotype of angiotensin M235T gene polymorphism is associated with highest renin activity and highest 24-h diastolic BP in comparison with MT and MM genotypes in patients with preeclampsia. Plasma aldosterone level is lower in patients with preeclampsia, but this is not related to angiotensinogen M235T gene polymorphism.

Topics: Aldosterone; Alleles; Angiotensinogen; Blood Pressure; Female; Gene Frequency; Genotype; Humans; Phenotype; Polymorphism, Single Nucleotide; Pre-Eclampsia; Pregnancy; Pregnancy Trimester, Third; Renin; Renin-Angiotensin System

To investigate the association of angiotensinogen (AGT) gene polymorphisms and angiogenic factors with preeclampsia (PE) in Chinese women.. A study on Chinese women was performed. Detection of the M235T polymorphism of AGT gene was carried out by PCR. Using a χ² test, genotype and allele frequencies were compared in all groups. Maternal serum levels of vascular endothelial growth factor (VEGF) and placental growth factor (PlGF) and soluble fms-like tyrosine kinase 1 (sFlt1) at gestation were compared between 92 women with PE and 100 controls by ELISA.. Compared to the controls, the AGT homozygous of TT genotype in PE occurred significantly more frequently and the T allele was observed to occur more frequently than the M allele (p < 0.05). sFlt1 was present in high quantities in the serum of women with PE and was associated with low levels of free VEGF and PlGF (p < 0.05). Plasma sFlt1 levels are higher in PE patients with TT heterozygotes compared with MM homozygotes, but PIGF is lower (p < 0.05). Plasma VEGF concentrations showed no significant difference.. Our study showed that AGT M235T polymorphism is associated with PE in Chinese women. Furthermore, the gene polymorphism of the components of the renin-angiotensin system may contribute to the concentration alterations of sFlt1, VEGF, and PlGF in maternal serum, which causes disordered vasculogenesis contributing to PE.

Topics: Adult; Alleles; Angiotensinogen; Chi-Square Distribution; China; DNA; Enzyme-Linked Immunosorbent Assay; Female; Humans; Placenta Growth Factor; Polymerase Chain Reaction; Polymorphism, Single Nucleotide; Pre-Eclampsia; Pregnancy; Pregnancy Proteins; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factor Receptor-1

There is an inverse correlation between human birthweight and umbilical venous angiotensin II (AngII) concentrations. Oxidative stress and increased pro-renin receptor (PRR) both enhance the cleavage of angiotensin I from angiotensinogen (AGT). Pre-eclampsia, a hypertensive disorder of pregnancy, manifests as high blood pressure and proteinuria, and is a state of increased oxidative stress.. Pre-eclampsia will be associated with increased placental expression of components of the renin-angiotensin system, which could result in reduced infant birthweight. Biopsies were taken 1 cm from the placental edge from 27 normotensive controls and 23 pre-eclamptic White European women. Immunohistochemistry was performed for AGT, PRR, glutathione peroxidase 3 (GPx3) and the AT1R and AT2R AngII receptors. Protein expression was semi-quantitatively assessed (H-score).. AT1R expression was significantly increased in pre-eclamptic placentae, and negatively correlated with birthweight (r = -0.529, P = 0.009). AT1R expression was also negatively correlated with GPx3 expression overall (r = -0.647; P = 0.005). AT2R expression positively correlated with AGT (r = 0.615, P = 0.002) in the pre-eclamptic placentae only.. The raised AT1R expression in pre-eclampsia, together with inadequate antioxidant protection, possibly through lower GPx activity, might enhance the vasoconstrictor effect of locally-generated AngII, contributing to the restricted fetal growth characteristic of pre-eclampsia. Conversely, the AT2R:AGT association within the pre-eclamptic placenta may provide a compensatory mechanism.

Topics: Angiotensinogen; Case-Control Studies; Female; Glutathione Peroxidase; Humans; Immunohistochemistry; Infant, Low Birth Weight; Infant, Newborn; Male; Oxidative Stress; Placenta; Pre-Eclampsia; Pregnancy; Prorenin Receptor; Receptor, Angiotensin, Type 1; Receptor, Angiotensin, Type 2; Receptors, Cell Surface; Renin-Angiotensin System; Trophoblasts

Several studies have reported the association of genes related to vascular tone, hypertension, oxidative stress and preeclampsia. We investigated the possible association among three polymorphisms in eNOS (as well their haplotypes): one of MTHFR, one of GSTP1 and one of AGT, with severe preeclampsia in Mexican-Mestizo women.. Two hundred thirty women with severe preeclampsia and 350 control subjects were genotyped; for rs2070744 and rs1799983 of eNOS, rs1801133 of MTHFR, rs1695 of GSTP1 and rs699 of AGT we used real-time PCR allelic discrimination and for VNTR of eNOS, PCR. Allele frequency differences were assessed by χ(2). Logistic regression was used to test for associations and for haplotype frequencies using Haploview 4.2.. Genotypic and allelic distribution of the polymorphisms was similar between cases and controls; likewise, haplotype frequencies of the three polymorphisms of eNOS did not differ significantly.. To our knowledge, this is the first time that these polymorphisms have been analyzed together and exclusively in women with severe preeclampsia. However, we did not find an association between polymorphisms of eNOS, MTHFR, GSTP1 and AGT with severe preeclampsia in our population. Additionally, we observed differences in the distribution of the alleles and genotypes of these polymorphisms in our population in comparison to those described in other ethnic groups.

Topics: Adult; Angiotensinogen; Female; Glutathione S-Transferase pi; Haplotypes; Humans; Hypertension; Methylenetetrahydrofolate Reductase (NADPH2); Mexico; Nitric Oxide Synthase Type III; Oxidative Stress; Polymorphism, Genetic; Pre-Eclampsia; Pregnancy

As a noninvasive examination, urinary proteomics is a very useful tool to identify renal disease. The purpose of the present study was to find differential proteins among women with preeclampsia, gestational hypertension and normal pregnancy, and to screen potential biomarkers for the early diagnosis of preeclampsia.. Urinary proteins were identified by iTRAQ labeling coupled with 2-D LC-MS/MS. The bioinformatics analysis was performed with the Metacore software and the International Protein Index (IPI) and the Gene Ontology (GO) Database. The differentially expressed proteins were verified by ELISA.. 362 nonredundant proteins were identified, 113 of which were expressed differentially between preeclampsia and normal pregnant group and 31 differential proteins among three groups. These differential proteins were associated with biological processes of blood coagulation, cell adhesion and differentiation, immune response and cytoskeleton development, etc. They interacted with each other in the network. The urinary angiotensinogen (AGT) was downregulated, which was consistent with the ELISA validation results.. The present study found a multitude of differential proteins that might provide a clue for investigating the mechanism of proteinuria development in preeclampsia. Low urinary angiotensinogen levels were useful for identifying preeclampsia.

Topics: Acute Kidney Injury; Adult; Angiotensinogen; Case-Control Studies; Chromatography, Liquid; Computational Biology; Enzyme-Linked Immunosorbent Assay; Female; Gene Expression Regulation; Humans; Hypertension, Pregnancy-Induced; Pre-Eclampsia; Pregnancy; Proteinuria; Proteomics; Reproducibility of Results; Staining and Labeling; Tandem Mass Spectrometry

To find association of angiotensin-converting enzyme (ACE) insertion/deletion (I/D), angiotensinogen (AGT) T704C, methylenetetrahydrofolate reductase (MTHFR) C677T and factor V Leiden (FVL) G1691A polymorphisms with pre-eclampsia (PE) in North Indian women.. In this prospective case-control study, genotyping of 200 pre-eclamptic women and 200 normotensive pregnant controls was performed for the ACE I/D, AGT T/C,MTHFR C/T and FVL G/A polymorphisms. Statistical analysis was carried out using SPSS and Epi Info to estimate their association with PE. The association of these polymorphisms with nonsevere PE and severe PE was separately assessed.. The FVL mutation was found in 4% of women and increased the risk of PE twofold (odds ratio [OR] 2.08, P-value 0.03). The MTHFR mutant allele was found to be protective (OR 0.59, P-value 0.01). Both these polymorphisms showed similar association with nonsevere PE (OR 2.149, P-value 0.038 and OR 0.565, P-value 0.222, respectively) but not with severe PE. The ACE I/D and AGT T/C polymorphisms were not found to be associated with PE overall (OR 1.26, P-value 0.11 and OR 1.15, P-value 0.35, respectively), but ACE I/D polymorphism was found to increase the risk of severe PE (OR 1.53, P-value 0.019).. FVL mutation is more common in North Indians than previously believed and it predisposes the women to PE. MTHFR mutant allele is paradoxically protective. ACE polymorphism appears to predispose to severe PE but not nonsevere PE. No significant contribution of AGT polymorphism to PE is found.

Topics: Adolescent; Adult; Alleles; Angiotensinogen; Asian People; Case-Control Studies; Factor V; Female; Genetic Predisposition to Disease; Genotype; Humans; India; Methylenetetrahydrofolate Reductase (NADPH2); Peptidyl-Dipeptidase A; Polymorphism, Genetic; Pre-Eclampsia; Pregnancy; Prospective Studies; Severity of Illness Index

The renin-angiotensin (Ang) system is important during placental development. Dysregulation of the renin-Ang system is important in preeclampsia (PE). Female rats transgenic for the human angiotensinogen gene crossed with males transgenic for the human renin gene develop the PE syndrome, whereas those of the opposite cross do not. We used this model to study the role of Ang II in trophoblast invasion, which is shallow in human PE but deeper in this model. We investigated the following groups: PE rats, opposite-cross rats, Ang II-infused rats (1000 ng/kg per day), and control rats. Ang II infusion increased only circulating Ang II levels (267.82 pg/mL), opposite cross influenced only uteroplacental Ang II (13.52 fmol/mg of protein), and PE increased both circulating (251.09 pg/mL) and uteroplacental (19.24 fmol/mg of protein) Ang II. Blood pressure and albuminuria occurred in the models with high circulating Ang II but not in the other models. Trophoblast invasion increased in PE and opposite-cross rats but not in Ang II-infused rats. Correspondingly, uterine artery resistance index increased in Ang II-infused rats but decreased in PE rats. We then studied human trophoblasts and villous explants from first-trimester pregnancies with time-lapse microscopy. Local Ang II dose-dependently increased migration by 75%, invasion by 58%, and motility by 282%. The data suggest that local tissue Ang II stimulates trophoblast invasion in vivo in the rat and in vitro in human cells, a hitherto fore unrecognized function. Conceivably, upregulation of tissue Ang II in the maternal part of the placenta represents an important growth factor for trophoblast invasion and migration.

Topics: Angiotensin II; Angiotensinogen; Animals; Animals, Genetically Modified; Brain; Cell Movement; Crosses, Genetic; Female; Fetal Growth Retardation; Humans; Liver; Male; Placenta; Pre-Eclampsia; Pregnancy; Pregnancy, Animal; Rats; Renin; Trophoblasts; Up-Regulation; Uterus

Preeclampsia is a debilitating disorder affecting approximately 3% of pregnant women in the Western world. Although inconclusive, current evidence suggests that the renin-angiotensin system may be involved in hypertension. Therefore, our objective was to determine whether the genes for placental renin (REN) and maternal angiotensinogen (AGT) interact to influence the risk of preeclampsia.. Three haplotype-tagging SNPs (htSNPs) covering REN (rs5705, rs1464818, and rs3795575) and another three covering AGT (rs2148582, rs2478545 and rs943580) were genotyped in 99 mother-father-child triads of preeclampsia pregnancies. We estimated relative risks (RR) conferred by maternal AGT and fetal REN haplotypes using HAPLIN, a statistical software designed to detect multi-marker transmission distortion among triads. To assess a combined effect of maternal AGT and fetal REN haplotypes, the preeclamptic triads were first stratified by presence/absence of maternal AGT haplotype C-T-A and tested for an effect of fetal REN across these strata.. We found evidence that mothers carrying the most frequent AGT haplotype, C-T-A, had a reduced risk of preeclampsia (RR of 0.4, 95% CI = 0.2-0.8 for heterozygotes and 0.6, 95% CI = 0.2-1.5 for homozygotes). Mothers homozygous for AGT haplotypes t-c-g and C-c-g appeared to have a higher risk, but only the former was statistically significant. We found only weak evidence of an overall effect of fetal REN haplotypes and no support for our hypothesis that an effect of REN depended on whether the mother carried the C-T-A haplotype of AGT (p = 0.33).. Our findings indicate that the mother's AGT haplotypes affect her risk for developing preeclampsia. However, this risk is not influenced by fetal REN haplotypes.

Topics: Angiotensinogen; Child; Female; Fetus; Gene Expression; Genes; Genotype; Haplotypes; Heterozygote; Homozygote; Humans; Hypertension; Polymorphism, Single Nucleotide; Pre-Eclampsia; Pregnancy; Regression Analysis; Renin; Renin-Angiotensin System; Risk Factors

Rats harboring the human angiotensinogen and human renin genes develop preeclamptic features in pregnancy. The preeclamptic rats exhibit a deeper trophoblast invasion associated with a reduced resistance index by uterine Doppler. Doxycycline inhibits matrix metalloproteinase activity. We tested the hypothesis that matrix metalloproteinase inhibition reduces trophoblast invasion with subsequent changes in placental perfusion. Preeclamptic and pregnant control Sprague-Dawley rats were treated with doxycycline (30 mg/kg of body weight orally) from gestational day 12 until day 18. Placental perfusion was assessed using a micromarker contrast agent. The animals were euthanized on day 18 of pregnancy; biometric data were acquired, and trophoblast invasion was analyzed. Doxycycline resulted in intrauterine growth retardation and lighter placentas in both groups. Maternal body weight was not affected. As shown earlier, preeclamptic rats exhibited a deeper endovascular trophoblast invasion. However, doxycycline treatment reduced trophoblast invasion in the preeclamptic rats. The physiological spiral artery remodeling, as assessed by the deposition of fibrinoid and alpha-actin in the spiral artery contour, was significantly reduced by doxycycline. The vascularity index, as assessed by perfusion measurement of the placenta, was reduced after doxycycline treatment in preeclamptic rats. Thus, matrix metalloproteinase inhibition with doxycycline leads to reduced trophoblast invasion and associated reduced placental perfusion. These studies are the first to show that reducing trophoblast-induced vascular remodeling decreases subsequent placental perfusion. Our model allows the study of dysregulated trophoblast invasion and vascular remodeling in vivo to gain important insights into preeclampsia-related mechanisms.

Topics: Angiotensinogen; Animals; Apoptosis; Arteries; Blood Pressure; Female; Humans; Organ Size; Placenta; Pre-Eclampsia; Pregnancy; Rats; Rats, Sprague-Dawley; Reference Values; Renin; Systole; Trophoblasts

Blood pressure is critically controlled by angiotensins, which are vasopressor peptides specifically released by the enzyme renin from the tail of angiotensinogen-a non-inhibitory member of the serpin family of protease inhibitors. Although angiotensinogen has long been regarded as a passive substrate, the crystal structures solved here to 2.1 Å resolution show that the angiotensin cleavage site is inaccessibly buried in its amino-terminal tail. The conformational rearrangement that makes this site accessible for proteolysis is revealed in our 4.4 Å structure of the complex of human angiotensinogen with renin. The co-ordinated changes involved are seen to be critically linked by a conserved but labile disulphide bridge. Here we show that the reduced unbridged form of angiotensinogen is present in the circulation in a near 40:60 ratio with the oxidized sulphydryl-bridged form, which preferentially interacts with receptor-bound renin. We propose that this redox-responsive transition of angiotensinogen to a form that will more effectively release angiotensin at a cellular level contributes to the modulation of blood pressure. Specifically, we demonstrate the oxidative switch of angiotensinogen to its more active sulphydryl-bridged form in the maternal circulation in pre-eclampsia-the hypertensive crisis of pregnancy that threatens the health and survival of both mother and child.

Topics: Amino Acid Sequence; Angiotensinogen; Angiotensins; Blood Pressure; Crystallography, X-Ray; Disulfides; Female; Humans; Kinetics; Models, Molecular; Molecular Sequence Data; Oxidation-Reduction; Oxidative Stress; Pre-Eclampsia; Pregnancy; Protein Conformation; Protein Processing, Post-Translational; Renin

The aim of these investigations was to study three candidate genes for pre-eclampsia--epidermal growth factor (EGF), transforming growth factor alpha, and angiotensinogen--in pregnant Sinhalese women from Sri Lanka, the first such study undertaken in this ethnic group. Reproducibility of results of genetic association studies of candidate genes for pre-eclampsia has not been consistent across populations. One of the factors that may contribute to such inconsistencies is genetic stratification due to population admixture. We therefore compared the allele frequencies of these candidate genes in healthy Sri Lankan subjects from three ethnic groups--Sinhalese, Sri Lankan Tamils and Moors--and in white Western Europeans.. Allele frequencies were established in 80 subjects from each of four populations (Sinhalese, Sri Lankan Tamils, and Moors in Sri Lanka and white Western Europeans in the U.K.). A further 175 Sinhalese women with pre-eclampsia and 171 normotensive Sinhalese controls were genotyped at eight single nucleotide polymorphisms in the candidate genes.. In all genes haplotype and allele frequencies were comparable within the three Sri Lankan populations, but differed significantly from those in the white Western European population. Consequently cryptic population stratification is unlikely to have significant effects on allele or haplotype frequencies of the genes examined in this case-control study of Sinhalese women which showed a marginal association for EGF haplotypes and genotypes with pre-eclampsia (P = 0.031). This association requires replication in other populations.

Topics: Adult; Angiotensinogen; Epidermal Growth Factor; Female; Haplotypes; Humans; Polymorphism, Single Nucleotide; Pre-Eclampsia; Pregnancy; Sri Lanka; Transforming Growth Factor alpha

Preeclampsia is the major cause of maternal and fetal mortality/morbidity. Because hypertension is an important risk factor for preeclampsia, we investigated whether hypertensive mice that overexpress human renin and angiotensinogen develop superimposed preeclampsia. Given that the mechanisms underlying this disease are still poorly understood, animal models are of great use for elucidation. Blood pressure and proteinuria were measured by telemetry and ELISA, respectively. Heart function was evaluated by echocardiography, whereas pathological cardiac hypertrophy-related genes were assessed by real-time PCR. Soluble fms-like tyrosine kinase 1 plasma concentrations were quantitated by ELISA and placental expression by real-time PCR. Transgenic mice develop de novo proteinuria during gestation and marked blood pressure elevation, which are hallmarks of superimposed preeclampsia on chronic hypertension. Abnormal placentation present in these mothers produced a significant decrease in pup and placental weight and was associated with an increased placental expression of soluble fms-like tyrosine kinase 1. We also found heightened circulating levels of this receptor, when adjusted for placental mass, as has been observed in women who suffer from preeclampsia. Cardiac hypertrophy could be observed in the transgenic mice and was exacerbated by gestation. As a result, heart function was significantly decreased, and markers of pathological hypertrophy were increased. Our data, thus, confirm the characterization of a new model of superimposed preeclampsia on chronic hypertension. Because chronically hypertensive women are at risk of developing the pathology, our model reflects a clinical reality and is, thus, an excellent tool to elucidate the molecular mechanisms triggering this disease.

Topics: Angiotensinogen; Animals; Animals, Newborn; Blood Pressure; Cardiomegaly; Chronic Disease; Disease Models, Animal; Female; Humans; Hypertension; Mice; Mice, Inbred C57BL; Mice, Transgenic; Placenta; Pre-Eclampsia; Pregnancy; Proteinuria; Renin; Renin-Angiotensin System

Genetic variants of the angiotensinogen gene have been linked to both hypertension and preeclampsia. The M235T polymorphism is more common in hypertension and preeclampsia in some populations. A polymorphism in the angiotensinogen basal promoter region of AGT -217 is more common in African Americans with hypertension. The authors investigated the frequency of M235T and AGT -217 in Caucasian and African American women with and without preeclampsia.. The study was a nested case-control study of primiparous women with singleton pregnancies. Genomic DNA from preeclamptic and control subjects underwent polymerase chain reaction amplification and restriction digestion.. The M235T and AGT -217 polymorphisms were both more common in African American women; however, the variants were not more common in preeclampsia.. The frequency of angiotensinogen polymorphisms M235T and AGT -217 is different by race; however, these polymorphisms are not associated with an increased risk of preeclampsia.

Topics: Adolescent; Adult; Angiotensinogen; Black or African American; Case-Control Studies; Cohort Studies; Female; Gene Frequency; Genetic Variation; Humans; Polymorphism, Genetic; Pre-Eclampsia; Pregnancy; Prospective Studies; Risk Factors; White People; Young Adult

To evaluate the influence of the angiotensinogen (AGT) gene on the individual predisposition to pre-eclampsia, we screened the AGT gene for pathogenic mutations and an association of identified polymorphisms in German women with pre-eclampsia.. The study population consisted of 67 German primi- and multigravid patients with pre-eclampsia or superimposed pre-eclampsia and 100 controls with uncomplicated singleton pregnancies. The initial screening for mutations was carried out in a subgroup of pre-eclampsia patients by single-strand conformation polymorphism analysis and direct sequencing.. Fifteen single nucleotide polymorphisms (SNPs) were detected, of which 14 had been described before. Allelic frequencies of the detected SNPs were estimated in the total study population. Only the promoter polymorphism g.-570C>T was associated with pre-eclampsia (p = 0.038) but after adjustment for multiple testing p was >0.05. The well-known M268T [M235T] polymorphism was not associated with pre-eclampsia.. Our results do not indicate an association of the AGT gene with pre-eclampsia. Data from previously published studies are conflicting: positive results were reported in at least 4 studies, negative results in 10 studies. A possible influence, if existing at all, is obviously very small. AGT therefore does not play a major role in the etiology of pre-eclampsia.

Topics: Adolescent; Adult; Alleles; Angiotensinogen; DNA; Female; Genetic Predisposition to Disease; Genetic Variation; Genotype; Humans; Infant, Newborn; Polymerase Chain Reaction; Polymorphism, Single Nucleotide; Pre-Eclampsia; Pregnancy; Young Adult

Maternal spiral artery remodeling is the consequence of controlled trophoblast invasive interaction with the maternal cellular environment and is fundamentally important for successful placentation. In preeclampsia, trophoblast invasion is shallow, remodeling is incomplete, and vessels develop an inflammatory appearance, termed "acute atherosis." We noted that, in our preeclampsia, human renin-human angiotensinogen transgenic rat model, complement component 3 (C3), and tumor necrosis factor-alpha were upregulated and heavily expressed in atherotic uteroplacental vessels. We next used coculture involving human trophoblasts, rat vascular smooth muscle cells (VSMCs), and human VSMCs to observe VSMC-trophoblast regulatory interactions. Tumor necrosis factor-alpha induced complement C3 and interleukin-6 expression in VSMCs. We found that trophoblasts were able to reduce VSMC C3 and interleukin-6 expression after the VSMCs were stimulated with tumor necrosis factor-alpha. However, a direct VSMC-trophoblast cell-cell contact was necessary for this anti-inflammatory response. We also studied double-transgenic VSMCs that express inflammatory components and exhibit accelerated proliferation ("synthetic" phenotype). Trophoblasts could not downregulate C3 in these cells. We then examined uteroplacental tissues from preeclamptic and control patients. In control deciduas, only traces of C3 staining were observed, and vessels were thin walled without thrombus formation. In preeclampsia, the decidual vessels showed atherosis, thrombus formation, and C3 expression. Our data suggest that fetally derived trophoblasts require direct cell-cell contact with maternally derived VSMCs to downregulate VSMC C3 and interleukin-6 expression and to avoid atherosis. The findings also implicate C3 in the placental vasculopathy observed in preeclampsia.

Topics: Acute Disease; Angiotensinogen; Animals; Animals, Genetically Modified; Atherosclerosis; Cell Communication; Cells, Cultured; Chorionic Villi; Coculture Techniques; Complement C3; Decidua; Female; Humans; Male; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Pre-Eclampsia; Pregnancy; Rats; Rats, Sprague-Dawley; Renin; Thrombosis; Trophoblasts

The chorionic villi in the placenta are responsible for the regulation of fetal oxygen and nutrient transport. Although the peripheral renin-angiotensin system is activated during normal pregnancy, the regulation of the local chorionic villi renin-angiotensin system remains unknown. Therefore, placental chorionic villous tissue was collected from nulliparous third-trimester normotensive or preeclamptic subjects and was analyzed for angiotensin peptide content, angiotensinogen, renin, angiotensin-converting enzyme (ACE), ACE2, neprilysin, angiotensin II type 1 (AT(1)), angiotensin II type 2, Mas receptor mRNAs, and angiotensin receptor density and subtype. Angiotensin II in chorionic villi was significantly higher in preeclamptic subjects, whereas angiotensin (1-7) was not different. Angiotensinogen and AT(1) receptor gene expression was significantly higher in preeclamptic subjects. No differences were observed in renin, ACE, ACE2, or neprilysin gene expression. Mas receptor mRNA in preeclamptic subjects was decreased. The AT(1) receptor was the predominant receptor subtype in normal and preeclamptic chorionic villi. There was no difference in the density of the AT(1,) angiotensin II type 2, and angiotensin (1-7) receptors. These results indicate that enhanced chorionic villous expression of angiotensin II may result from increased angiotensinogen. Elevated angiotensin II, acting through the AT(1) receptor, may favor vasoconstriction in placental chorionic villi and contribute to impaired fetal blood flow and decreased fetal nutrition observed during preeclampsia.

Topics: Adult; Angiotensin I; Angiotensin II; Angiotensinogen; Chorionic Villi; Female; Gene Expression; Humans; Neprilysin; Peptide Fragments; Peptidyl-Dipeptidase A; Placenta; Pre-Eclampsia; Pregnancy; Proto-Oncogene Mas; Proto-Oncogene Proteins; Receptor, Angiotensin, Type 1; Receptor, Angiotensin, Type 2; Receptors, G-Protein-Coupled; Renin-Angiotensin System

The aim of the present study was to evaluate the depth of endovascular trophoblast invasion and associated remodelling of spiral arteries in a transgenic model of pre-eclampsia in the rat, a species showing a comparable deep invasion during normal pregnancy as the human. Pre-eclamptic (PE) transgenic rats (TGR) (hAngiotensinogen female x hRenin male) and non-PE reversely mated (RM) TGR rats were compared to normal Sprague-Dawley rats (C). Day 18 implantation sites were collected and the presence of endovascular trophoblast, fibrinoid, endothelial and smooth muscle cells were evaluated in spiral arteries in three parallel layers in the mesometrial triangle using an image analysis system (KS-400). In a separate group of animals peak-systolic and end-diastolic velocities were measured by Doppler in uterine and arcuate arteries, and the resistance indices (RI) were calculated. In PE and RM rats, the entire mesometrial triangle contained significantly more endovascular trophoblast and vascular fibrinoid deposits than the C group. No difference was found between the groups in the overall amount of smooth muscle surrounding the lumen, but in the PE and RM groups significantly more muscle was present in parts of the contours covered by trophoblast. There was significantly less CD31-positive endothelium in the total lumen contours of the PE and RM groups than in the C group, but in parts of the contours covered by trophoblast more residual endothelium was present in both TGR groups. Comparison of the three layers indicated deeper invasion in both the PE and RM groups than in the C group. By Doppler analysis of the proximal uterine artery the RI was found to be significantly lower in the PE and the RM group than in the C group. In the arcuate artery, the RI was significantly lower in the PE group as compared to the RM and C groups. We conclude that in this transgenic PE rat model there is deeper endovascular invasion of spiral arteries and decreased RI of uterine arteries at day 18 of pregnancy.

Topics: Angiotensinogen; Animals; Animals, Genetically Modified; Arteries; Cell Adhesion; Disease Models, Animal; Endothelium, Vascular; Female; Hemodynamics; Male; Placental Circulation; Pre-Eclampsia; Pregnancy; Rats; Rats, Sprague-Dawley; Renin; Trophoblasts; Uterus

We recently demonstrated that renin-angiotensin system (RAS) overactivity during late gestation in rats is associated with increased kidney and urine levels of ANG-(1-7) and enhanced kidney immunostaining of ANG-(1-7) and angiotensin-converting enzyme 2 (ACE2). To understand the temporal-spatial changes in normal and hypertensive pregnancies, the renal distribution of ANG-(1-7) and ACE2 in association with kidney angiotensin peptides and ACE2 activity was examined in virgin, normal pregnant (NP; gestational days 5, 15, and 19) and reduced uterine perfusion pressure (RUPP at day 19) pregnant Sprague-Dawley rats. ANG-(1-7) and ACE2 immunocytochemical staining increased 1.8- and 1.9-fold and 1.7- and 1.8-fold, respectively, at days 15 and 19 of NP, compared with virgin rats. ANG-(1-7) and ANG II concentrations were increased in the kidney at 19 days of gestation. ACE2 activity measured using a fluorescent substrate was increased 1.9- and 1.9-fold in the cortex and 1.9- and 1.8-fold in the medulla at days 15 and 19 of NP. In the RUPP animals, ANG-(1-7) immunostaining and concentration were significantly decreased compared with 19-day NP rats. ACE2 activity was unchanged in the cortex and medulla of RUPP rats. In conclusion, during NP, the concurrent changes of ACE2 and ANG-(1-7) suggest that ACE2 plays an important role in regulating the renal levels of ANG-(1-7) at mid to late gestation. However, the decrease in renal ANG-(1-7) content in the absence of a concomitant decrease in ACE2 implicates the participation of other ANG-(1-7) forming or degrading enzymes during hypertensive pregnancy.

Topics: Angiotensin I; Angiotensin-Converting Enzyme 2; Angiotensinogen; Animals; Blood Pressure; Body Weight; Estradiol; Female; Fluorescent Antibody Technique; Hypertension, Pregnancy-Induced; Immunohistochemistry; Kidney; Peptide Fragments; Peptidyl-Dipeptidase A; Pre-Eclampsia; Pregnancy; Pregnancy, Animal; Proteinuria; Rats; Rats, Sprague-Dawley; Regional Blood Flow; Renin; Urodynamics; Uterus

Components of the renin-angiotensin system and endothelial nitric oxide synthase may co-operate in spiral artery remodelling during placentation, and thus reduce the uteroplacental resistance typical of normal pregnancy. Since lack of such remodelling and abnormal placentation are specific features of pre-eclampsia, it has been suggested that abnormal function of both components of the renin-angiotensin system and endothelial nitric oxide synthase may be involved in its pathogenesis. However, previous studies of the association between pre-eclampsia and polymorphisms of single genes encoding renin-angiotensin system components and endothelial nitric oxide synthase have yielded conflicting results. The aim of this study was to assess if interactions among different polymorphisms of the renin-angiotensin system and nitric oxide synthase are involved in the pathogenesis of pre-eclampsia.. Some 359 pregnant women were enrolled: 103 normotensive, 50 with chronic hypertension, 86 with gestational hypertension, and 120 with pre-eclampsia. DNA analysis was performed to evaluate angiotensin-converting enzyme I/D, angiotensin-II receptor 1 1166A/C, angiotensinogen M235T and endothelial constitutive nitric oxide synthase 4b/a polymorphisms. Odds ratios (OR) with 95% confidence interval (CI) and chi2 tests were calculated.. The frequency of single gene polymorphisms was similar in each group. The frequency of pairs including the DD genotype of the angiotensin-converting enzyme I/D polymorphism plus other homozygous genotypes was significantly higher in pre-eclamptic patients than in controls (OR=3.04, 95% CI=1.16-7.93).. Synergism of angiotensin-converting enzyme I/D and other polymorphisms of renin-angiotensin system components and nitric oxide synthase may be a risk factor for pre-eclampsia.

Topics: Adult; Alleles; Angiotensinogen; DNA; Female; Genotype; Humans; Minisatellite Repeats; Nitric Oxide Synthase Type III; Peptidyl-Dipeptidase A; Polymorphism, Single Nucleotide; Pre-Eclampsia; Pregnancy; Receptor, Angiotensin, Type 1; Renin-Angiotensin System

In 2003, the angiotensinogen (AGT) gene was found to be associated with infants small for gestational age (SGA). The present study of 107 pregnancies affected by SGA infants and 101 normal pregnancies was designed to further investigate this association. Maternal or fetal AGT genotype or haplotype frequencies did not differ between SGA and normal pregnancies (P > 0.35). Quantitative trait analysis of mothers with normal pregnancies demonstrated an association between AGT haplotype and blood pressure and body mass index at antenatal booking (P = 0.04), suggesting that AGT may play a role in the complex relationship between body mass and blood pressure in healthy pregnant women.

Topics: Adult; Angiotensinogen; Blood Pressure; Body Mass Index; Case-Control Studies; Female; Genetic Predisposition to Disease; Genetic Variation; Genotype; Gestational Age; Humans; Hypertension, Pregnancy-Induced; Infant, Newborn; Infant, Small for Gestational Age; Maternal Age; Pre-Eclampsia; Pregnancy

Renin-angiotensin System is essential for the homeostasis of blood pressure in humans. The roles of renin-angiotensin system gene polymorphisms including angiotensinogen, angiotensin-converting enzyme, renin and angiotensin II receptor, type 1 genes in the pathogenesis of preeclampsia have been extensively studied, but most association studies produced either negative or inconsistent results. Prolylcarboxypeptidase encodes a lysosomal enzyme and is a regulator for both renin-angiotensin system and the kallikrein-kinin system. There is no published study on prolylcarboxypeptidase gene and preeclampsia.. We investigated the independent and joint association of five polymorphisms in angiotensinogen, angiotensin-converting enzyme, and prolylcarboxypeptidase gene and chronic hypertension with the risk of preeclampsia in 125 preeclamptic and 1040 non-preeclamptic black women enrolled at the Boston Medical Center. We used logistic regression models to estimate the odds ratios of risk for preeclampsia associated with each gene polymorphism and its joint association with chronic hypertension.. No association was found in four polymorphisms in angiotensinogen and angiotensin-converting enzyme. Prolylcarboxypeptidase E112D (rs2298668) D allele along and jointly with chronic hypertension were associated with a significantly increased risk of preeclampsia. Compared to women with homozygous EE genotype and without chronic hypertension, higher risks of preeclampsia were observed in DD women without chronic hypertension (OR = 3.7, 95% CI, 1.2 - 12.4) and EE women with chronic hypertension (OR = 9.1, 95% CI: 4.7 - 17.6). Women with both D allele and chronic hypertension had the highest risk (OR = 158, 95% CI, 25-infinite). This finding was validated in an independent sample of 1,015 non-black women. We further compared the prolylcarboxypeptidase transcript levels in peripheral blood cells of 23 preeclamptic (30% with chronic hypertension) and 51 non-preeclamptic (6% with chronic hypertension) women 2 - 3 days after delivery. The PRCP transcript levels were lower in ED/DD women than in EE woman (P = .03) and lower in preeclamptic women than in non-preeclamptic women (P = .007).. Our data showed that prolylcarboxypeptidase D allele coupled with chronic hypertension was associated with a significantly increased risk of preeclampsia in both black and non-black women. Gene expression assays lent further support for the functional significance of prolylcarboxypeptidase in the etiology of preeclampsia.

Topics: Adult; Angiotensinogen; Black or African American; Boston; Carboxypeptidases; Case-Control Studies; Chronic Disease; Female; Gene Expression; Genotype; Humans; Hypertension; Odds Ratio; Peptidyl-Dipeptidase A; Phenotype; Polymorphism, Single Nucleotide; Pre-Eclampsia; Pregnancy; Renin-Angiotensin System; White People

We used rats transgenic for the human angiotensinogen (hAogen) gene and the human renin (hRen) gene and crossed the strains to produce a model of preeclampsia in the dams. The female (n=9) hAogen x male hRen cross had severe (telemetry-measured) hypertension and albuminuria, which developed during the last trimester of pregnancy and subsided after delivery. The converse cross (n=9) and control (n=9) SD rats did not. We demonstrated that the female hAogen x male hRen cross had agonistic antibodies capable of activating the angiotensin (Ang) II AT1 receptor (AT1R-AA) and defined the epitope on the receptor's second extracellular loop. The phenomenon also occurs in humans with preeclampsia. The rats displayed renal histology reminiscent of preeclampsia, including fibrin deposition confined to the glomeruli. The complement system was activated in glomeruli and IgG deposits were present that may represent AT1R-AA. Finally, we observed an atherosis-like lesion in the spiral arteries of the placental bed, which we called placental-bed arteriolosclerosis. Our model may be relevant to preeclampsia in humans.

Topics: Angiotensinogen; Animals; Animals, Genetically Modified; Autoantibodies; Complement Activation; Female; Fibrin; Humans; Immunoglobulin G; Kidney Glomerulus; Male; Pre-Eclampsia; Pregnancy; Rats; Rats, Sprague-Dawley; Receptor, Angiotensin, Type 1; Renin

Several association studies of candidate genes for preeclampsia and essential hypertension have led to discordant results, partly because of small sample sizes. Using a large population-based sample of pregnant women, we conducted an association study of 10 polymorphisms in 9 genes and aimed (1) to validate 10 published associations with preeclampsia or essential hypertension, (2) to investigate candidate polymorphisms previously associated with preeclampsia for association with essential hypertension and similarly with polymorphisms previously associated with essential hypertension. From a prospective sample of 3391 nulliparous French Canadian pregnant women, we identified 180 cases of preeclampsia, 203 cases of essential hypertension that were matched with normotensive control subjects (n=310 and 357, respectively). Polymorphisms were genotyped by allele-specific PCR. Among our candidate polymorphisms, the Met allele of Thr174Met of AGT was associated with preeclampsia (P=0.0033). Haplotype analysis revealed that the A-Met-Thr (G1035A-Thr174Met-Met235Thr) haplotype was associated with a 2.1-fold increased risk of preeclampsia (95% CI, 1.4 to 3.4; P=0.0008). In conclusion, we observed a strong association between a specific AGT haplotype and preeclampsia in our population, without replicating previous published associations with either preeclampsia or essential hypertension. Our data support a role for AGT in genetic susceptibility to preeclampsia.

Topics: Adult; Angiotensinogen; Female; Genetic Predisposition to Disease; Haplotypes; Humans; Hypertension; Polymorphism, Genetic; Pre-Eclampsia; Pregnancy; Prospective Studies

We tested the hypothesis that angiotensin-converting enzyme (ACE) and angiotensinogen gene polymorphism influence the incidence, development and outcome of preeclampsia. Subjects were recruited from 90 Korean patients with preeclampsia during pregnancy and 98 age-matched controls. After isolation of DNA, polymerase chain reactions (PCR) were carried out to detect polymorphism of the ACE and angiotensinogen. M235T and T174M genotypes of angiotensinogen were determined by digestion with restriction enzyme endonuclease Tth 111-I and NCo I, respectively. The frequency of DD genotype was significantly greater in preeclampsia (0.36) than in controls (0.14) (p<0.05). The frequency of D allele was 0.55 in preeclampsia and 0.40 in controls (p<0.05). There were no differences in the onset of preeclampsia and pregnancy outcomes according to the ACE genotypes. There was no difference in the frequency of a allele of angiotensinogen M235T between the groups (0.79:0.78 in preeclampsia : controls). The frequency of T allele of angiotensinogen T174M gene was slightly increased, but not significantly, in preeclampsia (0.11) than in controls (0.07). In a multivariate analysis, only ACE genotype was associated with the development of preeclampsia (beta=0.27, p=0.05). In conclusion, a molecular variant of ACE, but not angiotensinogen, gene is associated with preeclampsia in Korean women.

Topics: Adult; Angiotensinogen; Female; Gene Frequency; Genotype; Humans; Korea; Peptidyl-Dipeptidase A; Polymorphism, Genetic; Pre-Eclampsia; Pregnancy

To examine whether polymorphisms in the renin-angiotensin system (RAS) are associated with pregnancy-related hypertensive disorders in a black South African population.. The angiotensin-converting enzyme (ACE) insertion/deletion, angiotensinogen M235T and angiotensin II receptor type 1 1166A<--C polymorphisms were assessed in study groups comprising 204 women with pre-eclampsia, 120 with eclampsia, 67 with early onset pre-eclampsia and 78 with gestational hypertension.. Using chi analysis, results were compared with those obtained from 338 ethnically matched normotensive pregnant women following normal full term pregnancies. No significant differences in the distribution of any of these polymorphisms were found between patients with pre-eclampsia or eclampsia and the normal control subjects. Patients with gestational hypertension were less frequently homozygous for the ACE insertion polymorphism compared with controls (5 versus 13%, respectively; P = 0.049; odds ratio 0.36 [95% confidence interval (CI) 0.09-1.04]).. The commonly occurring RAS polymorphisms are not predictive of pre-eclampsia or eclampsia in the Black South African population.

Topics: Adult; Angiotensinogen; Black People; Female; Genetic Predisposition to Disease; Heterozygote; Homozygote; Humans; Hypertension, Pregnancy-Induced; Peptidyl-Dipeptidase A; Polymorphism, Genetic; Pre-Eclampsia; Pregnancy; Receptor, Angiotensin, Type 1; South Africa

Carriage of thrombophilic and vasoactive polymorphic alleles has been associated with various pregnancy complications. The effect of carrying multiple polymorphisms is not known. We conducted a case-control study to determine the association between eight polymorphisms of thrombophilic and vasoactive genes and the risk of severe preeclampsia.. The following polymorphisms were analyzed by sequencing-on-chip-technology using solid-phase polymerase chain reaction on oligonucleotide microarrays: factor 5 (F5) Leiden, factor 2 (F2)-prothrombin G20210A, plasminogen activator inhibitor (PAI)-1 4G/5G, nitric oxide synthase (NOS) 3 T768C, NOS 3 Glu298Asp, angiotensinogen (AGT) Met235Thr, estrogen receptor (ER) alpha Pvu II, and mineralcorticoid receptor (MLR) Ser810Leu. The study comprised 24 patients with severe preeclampsia and 24 controls from a cohort of consecutive white women treated at the Obstetrics Department of the University of Vienna Medical School. Genotypes were correlated with clinical data.. The investigated polymorphisms did not influence the risk of severe preeclampsia independently. When separately considering the simultaneous carriage of multiple thrombophilic or vasoactive polymorphisms, neither the combined carriage of thrombophilic polymorphisms (F5 Leiden, F2 G20210A, PAI-1 4G/5G), nor the combined carriage of vasoactive polymorphisms (NOS 3 T768C, NOS 3 Glu298Asp, AGT Met235Thr) conferred an increased risk of severe preeclampsia. Cumulative genotype frequencies for at least two homozygous mutant genotypes, however, were nine of 24 (38%) and two of 24 (8%) for the study and control groups, respectively (P <.05). All of these nine women with severe preeclampsia had at least two homozygous mutant genotypes of four polymorphisms, ie, F5 Leiden, NOS 3 T768C, NOS 3 Glu298Asp, or ER alpha Pvu II.. Our data fail to document an independent significant influence of the investigated polymorphisms on the risk of severe preeclampsia. In an attempt to build a multigenetic model of severe preeclampsia, the combination of F5 Leiden, NOS 3 T768C, NOS 3 Glu298Asp, and ER alpha Pvu II was the most effective combination to predict the presence of severe preeclampsia in this small series of white women.

Topics: Adult; Angiotensinogen; Blood Coagulation; Blood Coagulation Factors; Blood Vessels; Case-Control Studies; Estrogen Receptor alpha; Female; Humans; Nitric Oxide Synthase; Nitric Oxide Synthase Type III; Oligonucleotide Array Sequence Analysis; Pilot Projects; Plasminogen Activator Inhibitor 1; Polymerase Chain Reaction; Polymorphism, Genetic; Pre-Eclampsia; Pregnancy; Prothrombin; Receptors, Mineralocorticoid

The contribution of genetic factors to preeclampsia has been well documented. However, there has not been any study done on the association between preeclampsia and the angiotensinogen (AGT) M235T polymorphism and angiotensin-converting-enzyme (ACE) intron 16 insertion/deletion (I/D) polymorphism among Korean preeclampsia women. We performed a hospital-based case-control study on Korean women to investigate the association between preeclampsia and the angiotensinogen M235T polymorphism and also to determine the association between preeclampsia and the angiotensin-converting-enzyme intron 16 polymorphism.. DNA was extracted from whole blood of 104 preeclampsia patients and 114 healthy pregnant women. All samples were genotyped for all the polymorphisms using amplification after PCR of known allelic variants. Results were analyzed with the chi-square test, Student's t-test, and logistic regression.. 18 of 50 women with preeclampsia (36.0%) in nulliparous women and 15 of 37 women with preeclampsia (40.5%) in parous women were homozygous for methionine (M235) to threonine (T235) substitution at residue 235 of AGT gene, versus 12 of 38 women in nulliparous control women and 18 of 50 women in parous control women. There was no association between the AGT M235T polymorphism and preeclampsia according to age. Fourteen of 55 women with preeclampsia (25.5%) in nulliparous women and 11 of 39 women with preeclampsia (28.2%) in parous women were homozygous for the D allele of the ACE intron 16, versus 9 of 52 women in nulliparous control women and 16 of 53 women in parous control women. No association was demonstrated between D allele of ACE intron 16 and preeclampsia according to age. There were significant differences in birth weight and delivery weeks between controls and preeclampsia patients (P < 0.001). There were no significant differences in age and nulliparity between controls and preeclampsia patients.. The result indicates that the AGT M235T polymorphism and the ACE intron 16 polymorphism play no significant role in preeclampsia observed in Korean women.

Topics: Adult; Angiotensinogen; Case-Control Studies; Female; Humans; Introns; Korea; Peptidyl-Dipeptidase A; Polymorphism, Genetic; Pre-Eclampsia; Pregnancy

Intrauterine growth restriction has been associated with failed maternal physiologic changes such as abnormal spiral artery remodeling and reduced maternal blood volume. A polymorphism of angiotensinogen Thr235 has been considered a risk factor for preeclampsia. We genotyped maternal and fetal deoxyribonucleic acid (DNA) for angiotensinogen Thr235 to estimate whether the polymorphism is also a risk factor for intrauterine growth restriction.. We examined maternal blood DNA in 174 patients with intrauterine growth restriction and 60 patients with both preeclampsia and intrauterine growth restriction. The control group comprised 400 consecutive cases of women with term pregnancies and infants with birth weight between the fifth and 95th percentiles. We also examined 162 DNA samples from fetal blood with intrauterine growth restriction for the Thr235 polymorphism, and 240 normal fetuses were used as the control group. The angiotensinogen genotype was determined using mutagenically separated polymerase chain reaction. The products were size fractionated on an agarose gel. Angiotensinogen genotypes were divided into three groups: MM (homozygous for angiotensinogen Met235 allele), TT (homozygous for angiotensinogen Thr235 allele), and MT (heterozygous).. Maternal genotyping revealed a significantly higher Thr235 allele frequency in intrauterine growth restriction (.60) and preeclampsia/intrauterine growth restriction (.63) than in the control group (.36) (P <.001). Fetal genotyping revealed a Thr235 allele frequency of.59 in intrauterine growth restriction fetuses, as compared with the control group (.38) (P <.001).. Maternal and fetal angiotensinogen Thr235 genotypes are associated with an increased risk of intrauterine growth restriction in our study population. The angiotensinogen Thr235 allele may predispose women to deliver growth-restricted fetuses.

Topics: Adolescent; Adult; Alleles; Angiotensinogen; Base Sequence; Case-Control Studies; Female; Fetal Growth Retardation; Gene Frequency; Genetic Variation; Genotype; Humans; Molecular Sequence Data; Polymerase Chain Reaction; Polymorphism, Genetic; Pre-Eclampsia; Pregnancy; Pregnancy Outcome; Prenatal Care; Prenatal Diagnosis; Prevalence; Probability; Reference Values; Risk Assessment; Sensitivity and Specificity

Preeclampsia is considered to be a multifactorial and multisystemic disorder with a genetic predisposition. Alterations in the renin-angiotensin system are considered to play a significant role in the pathogenesis of the disease. In order to investigate the possible association of the three most common polymorphisms of the renin-angiotensin system genes with preeclampsia we have examined 41 women with preeclampsia and 102 normotensive pregnant women. DNA samples were genotyped for the M235T polymorphism of the angiotensinogen gene (AGT), the insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme gene (ACE) and the A1166C polymorphism of the angiotensin II type 1 receptor gene (AT1R) by PCR. Allele and genotype frequencies of the AGT gene polymorphism differed between the two study groups. The TT genotype of the M235T polymorphism was significantly increased in women who developed preeclampsia (P<0.02). In addition, women with preeclampsia and TT genotype had more frequently the DD genotype or the 1166C allele than the control group showing a significant interaction between the genes. In conclusion, we found an association between the angiotensinogen variant 235T and preeclampsia as well as an interaction between the variant 235T and the two other genes studied.

Topics: Alleles; Angiotensinogen; Female; Gene Frequency; Genotype; Humans; Peptidyl-Dipeptidase A; Polymerase Chain Reaction; Polymorphism, Genetic; Pre-Eclampsia; Pregnancy; Receptor, Angiotensin, Type 1; Renin-Angiotensin System

This study was designed to observe the genotype and allele frequency of angiotensinogen (AGT) and angiotensin-I converting enzyme (ACE) genes in pregnancy induced hypertension (PIH) and compare them with those in normal pregnant women.. Eighty-one women with pre-eclampsia (median age 28 years) and 205 normal pregnant women as controls (median age 28 years) from a population of Chinese Han nationality in Chengdu area participated in this study. The pregnant patients whose blood pressure exceeded 140/90 mmHg (or 18.7/12 kPa) were recruited with a rigorous definition of pre-eclampsia. Genotyping was performed using PCR-amplified DNA fragment for ACE I/D and PCR-RFLP for AGT polymorphism.. The allele frequencies of AGT235T and ACE D in PIH and normal pregnant women were 0.856 vs. 0.846 and 0.333 vs 0.364, respectively. No significant difference in these allele frequencies was observed between PIH and normal pregnant women. The allele frequencies of ACE D in Caucasians were higher than those in Chinese population (P < 0.001). The allele frequencies of AGT235T in Caucasians (0.350-0.482) and other populations (0.620-0.739) were lower than that in Chinese (0.846) (P < 0.01, P < 0.001).. There was no evidence in this study for the association of AGT M235T and ACE I/D polymorphism with pre-eclampsia in Chinese population in Chengdu area.

Topics: Adult; Angiotensinogen; Asian People; Female; Gene Frequency; Genetic Variation; Humans; Peptidyl-Dipeptidase A; Point Mutation; Pre-Eclampsia; Pregnancy

The regulation of blood pressure during pregnancy involves several biological pathways. Candidate genes implicated in hypertensive diseases during pregnancy include those of the renin-angiotensin system and nitric oxide synthase (NOS). We evaluated blood pressure and metabolic characteristics during pregnancy in mutant mice. These included mice with a null mutation in the endothelial NOS (eNOS) gene (Nos3(-/-)), four copies of the angiotensinogen gene (Agt(2/2)), and mutations in both genes [four copies of Agt and heterozygous deficient for eNOS (Agt(2/2)Nos3(+/-)), four copies of Agt and homozygous deficient for eNOS (Agt(2/2)Nos3(-/-))]. Blood pressure measurements of nulliparous females from mutant strains were compared with two common laboratory strains C57Bl6/J and SV129 throughout their first pregnancy. Serum and urine analysis for the evaluation of renal and liver physiology were measured in the prepregnant state and during the third trimester of pregnancy. Throughout pregnancy blood pressures in all mutant strains were higher compared with controls. Agt(2/2)Nos3(-/-) showed the highest blood pressures and C57Bl6/J the lowest. Control mice, but not mutant mice, showed a second trimester decline in blood pressure. No immediate differences were noted regarding behavioral characteristics, renal or liver function parameters. Mice deficient for eNOS, mice with overexpression of Agt, and mice with mutations in both genes demonstrated higher blood pressure throughout pregnancy. There was no evidence of renal dysfunction, liver dysfunction, or hemolysis among any of the strains studied. We conclude that Nos3 and Agt are important genes in the regulation of blood pressure during pregnancy.

Topics: Angiotensinogen; Animals; Area Under Curve; Behavior, Animal; Blood Pressure; Breeding; Disease Models, Animal; Energy Metabolism; Female; Gene Expression Regulation, Enzymologic; Genotype; Male; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Nitric Oxide; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Nitric Oxide Synthase Type III; Pre-Eclampsia; Pregnancy; Proteinuria

Preeclampsia is known to be a multifactorial disease. Recently, the angiotensinogen gene has been shown to be a candidate gene that could be related to preeclampsia, and acquired factors such as lifestyle during pregnancy have also been considered to be risk factors. The aim of this study was to investigate the interrelations among the angiotensinogen gene and various acquired risk factors in preeclampsia. Fifty-eight primiparous patients with pre-eclampsia were compared with 164 normal primiparous controls. A variant of the angiotensinogen gene (M235T) was analyzed along with the acquired factors obtained from both medical records and a questionnaire consisting of 98 questions. Univariate analysis disclosed 11 factors that were significantly associated with preeclampsia (P < .05). Multivariate analysis revealed four significant independent factors: "prepregnancy high body mass (body mass index > or = 24)," "T235 homozygotes of the angiotensinogen gene," "mentally stressful condition during pregnancy," and "salty dishes preferred during pregnancy." The odds ratios of the four factors were 6.2, 2.5, 3.0 and 2.6, respectively, in a multiple logistic model. Our results support the concept that T235 of the angiotensinogen gene is a potent, independent risk factor for preeclampsia, as well as other lifestyle-related risk factors.

Topics: Adult; Alleles; Angiotensinogen; Female; Humans; Multivariate Analysis; Polymorphism, Genetic; Pre-Eclampsia; Pregnancy; Risk Factors

We sought to establish an association between preeclampsia and the methionine to threonine polymorphism at amino acid residue 235 (Met235Thr) in angiotensinogen in a Hispanic population. We looked for a relationship between this allele and the allele in the endothelial nitric oxide synthase gene (NOS3) that produces the A form (NOS3*A) with respect to preeclampsia.. Clinical data were collected from 87 patients with preeclampsia and 53 control subjects. Patients and controls were genotyped for the angiotensinogen polymorphism allele (AGT*T) and the NOS3*A polymorphism. We then compared patients with preeclampsia and control subjects and investigated disease severity within the preeclampsia group as a function of genotype.. The AGT*T allelic frequencies among patients with preeclampsia and control subjects were 0.72 and 0.70, respectively (P =.84). The blood pressure of patients with an AGT*T allele who also carried a NOS3*A allele was higher at earlier gestational ages (r = -0.052; P =.02). Analysis suggested that the systolic blood pressure differences were due to gestational age effects and the presence of a NOS3*A allele (P <.10).. The AGT*T allele was not associated with the development of preeclampsia. Independently of the presence of an AGT*T allele, the NOS3*A allele was associated with a higher blood pressure at an earlier gestational age.

Topics: Adult; Alleles; Angiotensinogen; Blood Pressure; Female; Gene Frequency; Gestational Age; Hispanic or Latino; Humans; Nitric Oxide Synthase; Nitric Oxide Synthase Type III; Polymorphism, Genetic; Pre-Eclampsia; Pregnancy; Reference Values

The human placenta has been considered to possess a locally generated renin-angiotensin system (RAS), which may play a physiological role in the regulation of uteroplacental blood circulation. The changes in the expression of such a placental RAS during pregnancy could be important for the physiological and pathophysiological aspects of some clinical disorders, such as pregnancy-induced hypertension, preeclampsia. In the present study, the alterations of expression and localization of placental angiotensin II receptor subtypes, namely AT(1) in patients with preeclampsia (elective caesarean delivery) were investigated and compared with controls (vaginal delivery and elective caesarian delivery) using semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR), Western blot and immunohistochemistry respectively. Results from RT-PCR analysis revealed an upregulated expression of placental mRNA for AT(1) receptor subtype in patients with preeclampsia when compared with those in controls. In addition, there was also a significant activation of placental expression of angiotensinogen mRNA in patients with preeclampsia. Results from Western blot showed that the expression of AT(1) receptor was also upregulated. Immunohistochemical results further demonstrated that increased immunoreactivity for placental AT(1) receptor was predominantly localized to the thin layers of syncytiotrophoblasts and, to a less extent, the capillaries of the term placental villi. These data indicate that upregulation of placental RAS components, notably AT(1) receptor in the syncytiotrophoblasts, could play a pathophysiological role in patients with preeclampsia.

Topics: Angiotensinogen; Female; Humans; Immunohistochemistry; Placenta; Pre-Eclampsia; Pregnancy; Receptor, Angiotensin, Type 1; Receptors, Angiotensin; Renin-Angiotensin System; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tissue Distribution; Trophoblasts; Up-Regulation

The SHHF/Mcc-fa(cp) (spontaneous hypertension and heart failure) rat is advanced as a novel and suitable non-primate model of pregnancy-associated hypertension and fetal growth restriction because it simultaneously has spontaneous pregnancy-associated hypertension, small for gestational age (SGA) offsprings, and altered placental gene expression. Pregnancy-associated hypertension is a major contributor to maternal and fetal morbidity and mortality with the potential to result in maternal death and the need for iatrogenic preterm delivery. It has been reported to develop spontaneously in humans, but not in animals; consequently, progress in identifying the cause and pathogenesis of this disorder has been hampered. Spontaneous hypertension and heart failure rats develop hypertension spontaneously as they age, therefore we sought to determine whether these rats developed hypertension and SGA offsprings during pregnancy. Our results show that systolic blood pressure (BP) increased >40 mm Hg by the end of the first trimester and remained at this elevated level for the remainder of pregnancy, but decreased after parturition. Placenta weights of SHHF rats (0.60 +/- 0.02 g, n = 36) were significantly higher than Wistar-Kyoto (WKY) rats (0.42 +/- 0.01 g, n = 22, P < .05), but pup weights were significantly lower (2.68 +/- 0.06 g for SHHF rats compared to 3.24 +/- 0.06 g for WKY controls, P < .05). Histologic examination revealed pathologic lesions in neither heart, liver, placenta, nor kidney. L-Arginine administered in drinking water prevented the elevation of BP, particularly during the third trimester. Placentas from SHHF rats displayed altered expression of several genes whose protein products have been implicated in preeclampsia, including serotonin receptor, sodium channel, carbonic anhydrase, estrogen receptor regulator, major histocompatibility complex proteins, superoxide dismutase, and angiotensiogen. In addition, gene expression profiling showed alteration of a number of subcellular putative myristoylproteins not previously associated with preeclampsia, particularly those engaged in post-translational modifications in the placenta. Thus, SHHF rats may be a valuable tool, because it simultaneously has spontaneous pregnancy-associated hypertension, SGA offsprings, and altered placental gene expression.

Topics: Angiotensinogen; Animals; Birth Weight; Disease Models, Animal; Female; Fetal Growth Retardation; Fetal Weight; Gene Expression Profiling; Hypertension; Placenta; Pre-Eclampsia; Pregnancy; Pregnancy Complications, Cardiovascular; Protein Processing, Post-Translational; Rats; Rats, Inbred WKY; Rats, Mutant Strains

Hypertension in pregnancy (HP), including preeclampsia, is known to be a multifactorial disease. Recently, a Glu298Asp variant of the endothelial nitric oxide synthase gene (NOS3) was identified as being associated with coronary spasm and myocardial infarction, whereas it has been reported that endothelial nitric oxide synthase plays a role in HP. We therefore performed an association study of the Glu298Asp variant with HP among 152 HP patients and 335 normal pregnant control individuals, in the context of other risk factors before pregnancy. The frequency of the variant GA+AA NOS3 genotypes was significantly higher in the patients (0.23) than in the controls (0.12) (P < 0.01). Multivariate analysis revealed that family history of hypertension, TT genotype of the angiotensinogen gene (AGT), GA+AA NOS3 genotype, and prepregnancy body mass index > or = 24 were independent potent risk factors, after adjustment for maternal age and parity. The odds ratios of the factors were 2.7, 2.3, 2.2, and 2.1, respectively. Our results suggested that the Asp298 of NOS3 is a potent, independent risk factor for HP.

Topics: Angiotensinogen; Body Mass Index; Female; Genetic Variation; Genotype; Humans; Hypertension; Maternal Age; Multivariate Analysis; Nitric Oxide Synthase; Nitric Oxide Synthase Type III; Parity; Pedigree; Pre-Eclampsia; Pregnancy; Risk Factors

A mutation in the gene for angiotensinogen, changing the leucine residue at position 10 to a phenylalanine (L10F), has been reported in a patient with proteinuric pre-eclampsia. In vitro enzymatic studies suggest this mutation would increase production of the vasoactive peptide, angiotensin II in vivo, and therefore explain the etiology of the maternal hypertension.. To determine whether mutation of codon 10 of angiotensinogen is common in pre-eclampsia, and therefore likely to be involved in disease susceptibility.. We collected a cohort of 32 women with 'true' pre-eclampsia. All were normotensive prior to the 20th week of pregnancy, developed blood pressures consistently above 140/90 mmHg and had proteinuria of greater than 300 mg/day during the third trimester. All had blood pressures that returned to normal within 1 month of delivery; 31 women were primigravida. Genomic DNA was isolated from their peripheral blood lymphocytes for genetic analyses.. A polymerase chain reaction-restriction enzyme-based assay was devised to screen for mutation of codon 10 of the angiotensinogen gene. In addition, we determined the frequency of a threonine residue at position 235 in the angiotensinogen gene, given previous controversial findings of association of this polymorphism with disease.. We detected no mutation of codon 10 in angiotensinogen in any of the 32 women studied, indicating that this mutation is not commonly associated with proteinuric pre-eclampsia. Furthermore, there was no increased frequency of threonine 235 in the affected individuals studied compared with respective normotensive Caucasian-American and African-American populations.

Topics: Adult; Amino Acid Sequence; Angiotensinogen; Base Sequence; Codon; Cohort Studies; DNA Primers; DNA, Complementary; Female; Gene Frequency; Humans; Molecular Sequence Data; Point Mutation; Polymerase Chain Reaction; Polymorphism, Genetic; Pre-Eclampsia; Pregnancy

An association between preeclampsia (PE) and a common missense mutation of the methylenetetrahydrofolate reductase gene (MTHFR), a C to T substitution at nucleotide 677 (C677T), which converts an alanine to a valine residue, has been reported in Italian and Japanese populations. We examined 101 cases of hypertension in pregnancy (HP), including 73 cases of PE, and 215 normal pregnancy controls to confirm the association in Japanese women. No significant differences of the frequency of the T677 allele frequency or percentage of T677 homozygotes were detected among the various types of cases: HP (0.38, 12%, respectively), severe HP (0. 40, 12%), PE (0.38, 11%), severe PE (0.41, 11%), primiparous HP (0. 40, 12%), primiparous PE (0.44, 18%), nonelderly HP (0.39, 13%), nonelderly PE (0.40, 14%), nonobese HP (0.38, 12%), nonobese PE (0. 39, 10%), HP without homozygous T235 of the angiotensinogen gene (TT of AGT) (0.38, 15%), PE without TT of AGT (0.38, 15%), and controls (0.38, 15%). The results indicate that T677 of MTHFR may not be a risk factor for PE in Japanese population.

Topics: Adult; Alleles; Amino Acid Substitution; Angiotensinogen; Body Mass Index; DNA; Female; Gene Frequency; Humans; Hypertension; Japan; Maternal Age; Methylenetetrahydrofolate Reductase (NADPH2); Mutation; Oxidoreductases Acting on CH-NH Group Donors; Parity; Point Mutation; Pre-Eclampsia; Pregnancy; Pregnancy Complications, Cardiovascular; Pregnancy Outcome; Severity of Illness Index; Statistics as Topic

To compare the angiotensinogen genotypes in normotensive and pre-eclamptic pregnancies in maternal and fetal samples.. Prospective observational study.. University Hospital, Queen's Medical Centre, Nottingham.. Forty-three women with pre-eclampsia and 84 normotensive pregnant women. Fetal samples were available for genotyping from 96% of the pregnancies.. Maternal and fetal DNA was genotyped at angiotensinogen codon 235 and at a dinucleotide repeat polymorphism in the 3' flanking region of the gene. Angiotensinogen and renin concentrations were measured in maternal plasma by radioimmunoassay.. In contrast to earlier studies, no association was demonstrated between the angiotensinogen 235 Thr variant and pre-eclampsia. Normotensive pregnant women homozygous for this variant had significantly lower plasma angiotensinogen concentrations (median 2.2 ng AI/mL; IQR 1.8-3.0) than women homozygous for the 235 Met allele (3.6 ng AI/mL; IQR 2.5-4.1; P = 0.04). In pre-eclamptic pregnancies, 79% (11/14) of mothers heterozygous for the dinucleotide repeat allele designated A9 transmitted this allele to the fetus, more frequently than would be expected by chance (P = 0.02). The A9 allele was associated with low plasma angiotensinogen concentrations (P = 0.001) and high renin concentrations (P = 0.02) in normotensive women.. There is no evidence that the angiotensinogen 235 Thr allele is associated with pre-eclampsia in the Nottingham population. The angiotensinogen 235 Thr allele is associated with low plasma angiotensinogen concentrations in normotensive pregnant women, in contrast to the high levels associated with this variant in non-pregnant women, suggesting that regulation of angiotensinogen expression in normal pregnancy may differ significantly from that in the non-pregnant state. There is preliminary evidence that maternal-fetal transmission of an angiotensinogen allele associated with low plasma angiotensinogen concentrations is associated with pre-eclampsia. Impaired generation of angiotensin II at the maternal-fetal interface may be a factor in the pathogenesis of pre-eclampsia.

Topics: Adult; Alleles; Angiotensinogen; Female; Fetal Blood; Genotype; Humans; Polymorphism, Genetic; Pre-Eclampsia; Pregnancy; Prospective Studies; Renin

The contribution of genetic factors to hypertension in pregnancy, including pre-eclampsia, has been well documented. The association with a common molecular variant of the angiotensinogen (AGT) gene, in which methionine (M235) is substituted for threonine (T235) at residue 235, has been reported in both Caucasians and Japanese. In the present study, we examined 115 cases of pure type of hypertension in pregnancy (PHP) and 381 normal pregnant controls in order to look for subgroups in which the AGT gene is the major factor in the PHP pathogenesis. By classification of PHP cases according to the clinical diagnosis, gravidity, and maternal age, we found significantly higher frequencies of T235 in both all PHP patients and preeclampsia/eclampsia patients than in normal controls. These results are discordant with those reported for Caucasian subjects where only a group of preeclamptic primigravidae was associated with the AGT variant, possibly indicating the existence of a racial difference. We also found that the variant frequency was significantly higher in the PHP subgroup with maternal age of 20-34 years (0.93) than in a subgroup of multigravid PHP patients age 35 years or older (0.77, P < 0.05) or in normal controls of age 20-34 years (0.76, P < 0.001). The result indicates that the AGT variant plays a significant role in hypertension in the age group 20-34 years.

Topics: Adult; Age Factors; Alleles; Angiotensinogen; Asian People; Base Sequence; Case-Control Studies; DNA Primers; Female; Gene Frequency; Genetic Variation; Genotype; Humans; Hypertension; Japan; Pre-Eclampsia; Pregnancy; Pregnancy Complications, Cardiovascular

Preeclampsia is associated with a common molecular variant of angiotensinogen (Met235Thr). This variant is in tight linkage disequilibrium with a mutation in the angiotensinogen promoter, G(-6)A, which leads to elevated expression in vitro. Since angiotensin II levels could play a role in atherotic changes of the uterine spiral arteries associated with preeclampsia, we investigated angiotensinogen expression in the first trimester uterus. We localized angiotensinogen transcription in uterine decidua using in situ reverse transcription PCR. We then compared decidual T235 expression levels to M235 levels in heterozygous women using an allele-specific ligation assay and a single nucleotide primer extension assay. In human decidua, angiotensinogen is expressed only in spiral artery smooth muscle cells. Heterozygous women have significantly elevated expression of the T235 allele compared to the M235 allele (P < 0.0001). These observations suggest that elevated expression of the T235 allele in decidual spiral arteries may cause first trimester atherotic changes leading to preeclampsia.

Topics: Alleles; Angiotensinogen; Female; Heterozygote; Humans; Immunohistochemistry; Muscle, Smooth, Vascular; Mutation; Polymerase Chain Reaction; Pre-Eclampsia; Pregnancy; Promoter Regions, Genetic; RNA; RNA, Messenger; Trophoblasts; Uterus

Preeclampsia/eclampsia (PE/E) is a common disease of human pregnancy with a strong genetic component. The etiology of PE/E is unknown. Two recent reports indicated that the angiotensinogen gene (AGT) could be involved in susceptibility to PE/E. We performed a population-based case-control study in Australian and Chinese populations to investigate whether AGT is a good candidate gene for PE/E. A microsatellite polymorphism within AGT was typed as well as a molecular variant T235 (Met-->Thr) of AGT using allele-specific PCR and allele-induced restriction site PCR. The allele distributions of the microsatellite and the variant T235 of AGT were significantly different between the two ethnic groups. However, no significant allele associations were found with disease when comparing PE/E patients and controls in Australian or Chinese populations, which is in contrast to the two earlier reports. The results suggest that the contribution of AGT to the occurrence of PE/E is small, if anything, and is not constant across populations.

Topics: Alleles; Angiotensinogen; Australia; Case-Control Studies; China; Eclampsia; Female; Gene Frequency; Genetic Variation; Humans; Minisatellite Repeats; Polymerase Chain Reaction; Pre-Eclampsia; Pregnancy

Topics: Angiotensinogen; Asian People; Eclampsia; Female; Gene Frequency; Genotype; Humans; Indonesia; Japan; Polymorphism, Genetic; Pre-Eclampsia; Pregnancy

Pregnancy-induced hypertension (PIH) is considered to be a multifactorial disease. Genetic background plays an important role for the pathogenesis of PIH as well as environmental effects. Recently, an association between PIH and a molecular variant of angiotensinogen (AGT) gene, which encodes methionine (M235) or threonine (T235) at residue 235, was reported both in Caucasians and the Japanese women. In Caucasians, T235 was associated with preeclamptic primiparas (PE-PP), a diagnostic subgroup of PIH. However, in the Japanese, an association of T235 with PE-PP is not yet proven probably because of small sample size. To investigate this point, the author performed a case-control study, collecting 139 PIH samples including 68 PE-PP and 278 cases of age and parity (primiparous or multiparous) matched controls in Hokkaido area. Molecular variants of their AGT genes were typed by the method using polymerase chain reaction (PCR). Results showed frequencies of homozygote of T235 were significantly higher in PIH (80%, p < 0.001), PE-PP (87%, p < 0.001) and severe PE-PP (92%, p < 0.001) than in controls (56%). In the Japanese, the frequencies were significantly higher in PE-PP than in other forms of PIH (73%, p < 0.05), which is the same tendency as previously reported in Caucasians. The present results indicate that AGT is involved in the pathogenesis of both PIH and PE-PP in the Japanese women.

Topics: Adult; Angiotensinogen; Asian People; Case-Control Studies; Female; Genotype; Humans; Japan; Maternal Age; Parity; Polymerase Chain Reaction; Pre-Eclampsia; Pregnancy; Pregnancy Complications, Cardiovascular

Topics: Angiotensinogen; Female; Gene Frequency; Humans; Pre-Eclampsia; Pregnancy

Angiotensinogen exhibits genetic linkage to and association with essential hypertension and preeclampsia, a common hypertensive disorder of pregnancy; however, the polymorphisms detected thus far provide no functional clues. In a preeclamptic patient, we have identified a mutation leading to the replacement of leucine by phenylalanine at position 10 of mature angiotensinogen (L10F), the site of renin cleavage. Kinetic analyses of the enzymes of the renin-angiotensin system, using either model peptides or full-length substrates, show that this mutation significantly alters the reactions with both renin and angiotensin-converting enzyme. For the renin reaction on a full-length substrate, this substitution leads to a 10-fold decrease in Km (from 1.1 to 0.09 microM) and a 5-fold decrease in kcat (from 1.0 to 0.22 s-1); as a result, catalytic efficiency (kcat/Km) is increased by a factor of 2 (1.1 versus 2.4 microM-1 s-1). In the reaction of angiotensin-converting enzyme on angiotensin decapeptides, the substitution has no effect on Km (38.0 versus 30.0 microM), but increases kcat and catalytic efficiency > 2-fold (kcat = 15.0 versus 37.0 s-1; kcat/Km = 0.41 versus 1.23). The renin-angiotensin system, challenged by the profound physiological adaptations of pregnancy, is perturbed in preeclampsia; consequently, the L10F mutation may promote this condition in carrier subjects.

Topics: Angiotensinogen; Base Sequence; Female; Humans; Kinetics; Leucine; Molecular Sequence Data; Oligodeoxyribonucleotides; Peptides; Phenylalanine; Point Mutation; Pre-Eclampsia; Pregnancy; Renin; Renin-Angiotensin System; Substrate Specificity

Topics: Angiotensinogen; Female; Genotype; Humans; Polymorphism, Genetic; Pre-Eclampsia; Pregnancy

Topics: Alleles; Angiotensinogen; Base Sequence; Female; Genetic Predisposition to Disease; Humans; Iceland; Molecular Sequence Data; Polymorphism, Genetic; Pre-Eclampsia; Pregnancy; Prospective Studies; Proteinuria; Repetitive Sequences, Nucleic Acid; Scotland

Pregnancy-induced hypertension (PIH) is a heterogeneous disorder which complicates 5-7% of all pregnancies and remains a leading cause of maternal, fetal and neonatal morbidity and mortality. Severe preeclampsia is the most distinctive and life-threatening form; a multi-system disorder more common in first pregnancies, it is characterized by high blood pressure and proteinuria. In a series of Caucasian women with pregnancy-induced hypertension, we have observed a significant association of preeclampsia with a molecular variant of angiotensinogen, T235, found previously to be associated with essential hypertension. This finding is corroborated in a sample ascertained in Japan. Together, these observations support a new pathophysiological interpretation of preeclampsia and of its relation to some forms of essential hypertension.

Topics: Angiotensinogen; Asian People; Base Sequence; Female; Genetic Variation; Humans; Hypertension; Molecular Sequence Data; Parity; Polymerase Chain Reaction; Pre-Eclampsia; Pregnancy; Pregnancy Complications, Cardiovascular; Renin-Angiotensin System; White People

Topics: Angiotensinogen; Eclampsia; Female; Genotype; Humans; Hypertension; Pre-Eclampsia; Pregnancy; Pregnancy Complications, Cardiovascular; Pregnancy in Diabetics

The expression of renin and angiotensinogen genes in the human placenta and related tissues has been examined by RNA blot hybridization analysis with specific human complementary DNA (cDNA) probes. Renin mRNA was detectable in the chorion throughout pregnancy and in the hydatidiform moles, but not in the decidua, amnion or myometrium. The relative concentration of renin mRNA in the chorion was at the highest level in early pregnancy and decreased thereafter, while the total amount contained in the whole placenta was at the lowest level in early pregnancy, and increased thereafter, reaching at term about one-sixth of the total renin mRNA in the kidney. Hydatidiform moles had an even higher concentration of renin mRNA than the early chorion. There was no significant difference in either the relative concentration or the total renin mRNA content in the placentae from 4 normal and 4 toxemic pregnancies. Angiotensinogen mRNA was undetectable in any of the placental tissues, hydatidiform moles or myometrium. These results show that renin is synthesized in the placenta, possibly to play some physiological role locally by utilizing angiotensinogen which is abundantly present in the maternal systemic circulation.

Topics: Angiotensinogen; Female; Humans; Nucleic Acid Hybridization; Placenta; Pre-Eclampsia; Pregnancy; Renin; RNA, Messenger

Pre-eclampsia and 'essential' hypertension in pregnancy require to be studied separately. Their haemodynamic characteristics need to be determined and the effects of antihypertensive therapy and blood volume expansion explored. Diuretics should be used in pre-eclampsia only to treat cardiac failure. Hydrallazine may be contraindicated if cardiac failure is imminent. The role of propranolol remains undecided and a controlled trial is required. Studies of the renin-angiotensin system which take into account the various factors that alter renin secretion may prove useful.

Topics: Angiotensinogen; Blood Pressure; Female; Hemodynamics; Humans; Hypertension; Pre-Eclampsia; Pregnancy; Pregnancy Complications, Cardiovascular; Renin

Total and active renin concentrations (TRC and ARC) were determined in pregnant women and in women on estrogen-containing oral contraceptives to study the variation of plasma renin forms in pregnancy. TRC was already elevated in the first trimester. After that TRC increased consistently reaching the maximum in the third trimester. The ratio of inactive renin concentrations (IRC) to TRC was between 20 and 30% throughout gestation. Therefore, it was supposed that the development of the placenta or the enlargement of the uterus do not affect the ratio of IRC to TRC too much. In women on oral contraceptives in whom plasma renin activity was increased due to elevation of renin substrate, the ratio of IRC to TRC was almost the same as that in normal controls. From these results, it was suggested that the development of the placenta and the enlargement of the uterus do not play an important role in the variation of plasma renin forms, although remarkable changes are observed in the renin substrate and total amounts of renin in pregnancy.. Changes in total and active renin concentrations (TRC and ARC) during pregnancy were studied; in addition, the changes in TRC and ARC in women taking oral contraceptives (OCs) were also investigated. 20 pregnant women aged 21-34 years were studied. TRC and ARC levels in normal subjects were 3.6 ng/ml/hour and 3.1 mg/ml/hour, respectively. Inactive renin concentration (IRC) was determined and its ratio was calculated from (TRC-ARC)/TRC. In normal subjects, IRC ratio was widely dispersed. TRC in women on OCs was slightly higher than normal, but ARC was not significantly different. Mean level of IRC/TRC (33%) in OC users was higher than that of normal subjects, but it was not significantly different. TRC and ARC showed an increasing tendency in term plasma. In contrast, the maximal value of the IRC ratio was in the second trymester. BY 3-4 weeks postdelivery, TRC and IRC were back to normal levels. When these measurements were related to cases of toxemia, 2 toxemic women showed values of TRC and IRC lower than those in normal pregnant women. It is concluded that development of the placenta or enlargement of the uterus does not affect the IRC ratio.

Topics: Adult; Aldosterone; Angiotensinogen; Contraceptives, Oral; Contraceptives, Oral, Synthetic; Estradiol Congeners; Estrogens; Female; Humans; Pre-Eclampsia; Pregnancy; Pregnancy Trimester, First; Pregnancy Trimester, Second; Pregnancy Trimester, Third; Radioimmunoassay; Renin

To investigate the role of components of the renin-angiotensin-aldosterone system and plasma progesterone concentrations in the pathophysiology of hypertension in pregnancy, sequential measurements were made throughout pregnancy in 45 normotensive subjects, 41 other pregnant patients in whom hypertension became manifest only during pregnancy and 26 patients with chronic hypertension antedating pregnancy. Among the normotensive subjects plasma renin activity and substrate, plasma aldosterone and progesterone concentrations were elevated as early as the sixth week of gestation. While consistent, progressive, further increases were noted in renin substrate, aldosterone and pregesterone concentrations during pregnancy, plasma renin activity did not continue to rise. In both hypertensive groups, plasma renin activity and aldosterone concentration were significantly suppressed during the last trimester despite levels of renin substrate and progesterone that were not significantly different than those observed in normotensive pregnancy. These observations confirm earlier studies reporting suppression near term of plasma renin activity in toxemia and indicate from these prospective observations that they are secondary effects. These studies, in addition, demonstrate parallel suppression of plasma aldosterone concentration in toxemia. The current report also indicates that this suppression is not due to a decrease in renin substrate concentration and that a hypothesized deficiency of plasma progesterone, which was not observed in the hypertensive subjects, does not play a permissive role in the development of hypertension.

Topics: Aldosterone; Angiotensin II; Angiotensinogen; Female; Humans; Hypertension; Pre-Eclampsia; Pregnancy; Pregnancy Complications, Cardiovascular; Progesterone; Renin

Topics: Angiotensin II; Angiotensinogen; Blood Pressure; Chorion; Endopeptidases; Female; Humans; Kidney; Pre-Eclampsia; Pregnancy; Renin; Uterus