Preeclampsia Offspring Research Articles

AT1-AA Induced Placental Ischemia Contributes to Hypertension in Female Offspring

Objective: Preeclampsia (PE), new-onset hypertension during the third trimester of pregnancy alongside other organ dysfunction, is associated with chronic inflammation and fetal growth restriction. Agonistic autoantibodies against the angiotensin II type 1 receptor (AT1-AA) are produced in PE women and induce a PE-like phenotype when infused into pregnant rats. AT1-AA is still present in maternal circulation up to eight years postpartum. We have shown that AT1-AA exposure during pregnancy contributes to impairment of cerebral blood flow in the postpartum period. Moreover, PE offspring are at higher risk for cardiovascular disease and hypertension but AT1-AA’s role in this elevated risk is unknown. The objective of this study was to determine if AT1-AA contributes to the risk for hypertension in PE offspring. Therefore, we hypothesized that AT1-AA infusion during pregnancy would cause offspring to have low birth weight and hypertension in adulthood. Methods: We infused AT1-AA (1:40) starting on gestational day (GD) 14 and allowed the dams to give birth on GD21. Birth weight was measured within 12 hours. Offspring were aged to 4 months. At that time, one male and female per litter were randomly selected to undergo carotid catheterization. The following day mean arterial pressure (MAP) was measured and blood and tissues were collected. Immune cells were measured by flow cytometry. Sex hormones were measured by mass spectroscopy. AT1-AA was measured by cardiomyocyte bioassay. Renal endothelin was measured by ELISA and RT-PCR. A two-way ANOVA was used for statistical analysis. Results: AT1-AA male and female offspring (6.1±0.1g, n=19, p<0.05; 5.8±0.1g, n=19, p<0.05) were larger at birth than NP male and female offspring (5.8±0.1g, n=11; 5.5±0.1g, n=11). Female AT1-AA offspring had elevated MAP (124±2 mmHg, n=14, p<0.05) compared to NP female offspring (110±5 mmHg, n=8) while male AT1-AA offspring had similar MAP to male NP offspring. Circulating cytolytic NK cells trended higher in female AT1-AA offspring (2.73±0.37 % gated, n=9, p=0.0949) compared to female NP offspring (1.66±0.31 % gated, n=6). Female AT1-AA offspring also had elevated progesterone (41.3±6.0 pg/μL, n=8, p=0.0556) compared to female NP offspring (26.9±4.9 pg/μL, n=7). Renal PPET expression was increased in female AT1-AA offspring (2.6±0.69 fold increase, n=4, p<0.05) compared to female NP offspring. Renal endothelin-1 was increased in female AT1-AA offspring (1.02±0.23 pg/mg, n=7, p=0.062) compared to female NP offspring (0.59±0.06 pg/mg, n=6). Male and female AT1-AA offspring had increased circulating AT1-AA (9.5±2.2 ΔBPM, n=6, p<0.0001; 7.9±0.9 ΔBPM, n=8, p<0.001) compared to male and female NP offspring (-0.4±.4 ΔBPM, n=7; -0.8±0.4 ΔBPM, n=4). Conclusion: These data demonstrate that AT1-AA infusion during pregnancy can predispose female offspring to have elevated blood pressure in adulthood. This study was supported by NIH grants RO1HD067541 (BL), F31HD110230 (NC), P20GM121334 (BL, LMA), HL151407 (DCC) and American heart association (AHA) early career award 19CDA34670055 (LMA). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Pre-eclamptic foetal programming predisposes offspring to hepatic steatosis via DNA methylation

ObjectivesGamete and embryo–foetal origins of adult diseases hypothesis proposes that adulthood chronic disorders are associated with adverse foetal and early life traits. Our study aimed to characterise developmental changes and underlying mechanisms of metabolic disorders in offspring of pre-eclampsia (PE) programmed pregnancy. MethodsNω-Nitro-l-arginine methyl ester hydrochloride (L-NAME) induced pre-eclampsia-like C57BL/6J mouse model was used. Lipid profiling, histological morphology, indirect calorimetry, mRNA sequencing, and pyrosequencing were performed on PE offspring of both young and elderly ages. ResultsPE offspring exhibited increased postnatal weight gain, hepatic lipid accumulation, enlarged adipocytes, and impaired energy balance that continued to adulthood. Integrated RNA sequencing of foetal and 52-week-old livers revealed that the differentially expressed genes were mainly enriched in lipid metabolism, including glycerol-3-phosphate acyl-transferase 3 (Gpat3), a key enzyme for de novo synthesis of triglycerides (TG), and carnitine palmitoyltransferase-1a (Cpt1a), a key transmembrane enzyme that mediates fatty acid degradation. Pyrosequencing of livers from PE offspring identified hypomethylated and hypermethylated regions in Gpat3 and Cpt1a promoters, which were associated with upregulated and downregulated expressions of Gpat3 and Cpt1a, respectively. These epigenetic alterations are persistent and consistent from the foetal stage to adulthood in PE offspring. ConclusionThese findings suggest a methylation-mediated epigenetic mechanism for PE-induced intergenerational lipid accumulation, impaired energy balance and obesity in offspring, and indicate the potential benefits of early interventions in offspring exposed to maternal PE to reduce their susceptibility to metabolic disorder in their later life.

Growth-Restricted Fetuses and Offspring Reveal Adverse Sex-Specific Metabolic Responses in Preeclamptic Mice Expressing Human sFLT1.

Fetal adaptations to harmful intrauterine environments due to pregnancy disorders such as preeclampsia (PE) can negatively program the offspring's metabolism, resulting in long-term metabolic changes. PE is characterized by increased circulating levels of sFLT1, placental dysfunction and fetal growth restriction (FGR). Here we examine the consequences of systemic human sFLT1 overexpression in transgenic PE/FGR mice on the offspring's metabolic phenotype. Histological and molecular analyses of fetal and offspring livers as well as examinations of offspring serum hormones were performed. At 18.5 dpc, sFLT1 overexpression resulted in growth-restricted fetuses with a reduced liver weight, combined with reduced hepatic glycogen storage and histological signs of hemorrhages and hepatocyte apoptosis. This was further associated with altered gene expression of the molecules involved in fatty acid and glucose/glycogen metabolism. In most analyzed features males were more affected than females. The postnatal follow-up revealed an increased weight gain of male PE offspring, and increased serum levels of Insulin and Leptin. This was associated with changes in hepatic gene expression regulating fatty acid and glucose metabolism in male PE offspring. To conclude, our results indicate that sFLT1-related PE/FGR in mice leads to altered fetal liver development, which might result in an adverse metabolic pre-programming of the offspring, specifically targeting males. This could be linked to the known sex differences seen in PE pregnancies in human.

Meta-Analysis of Cardiovascular Risk Factors in Offspring of Preeclampsia Pregnancies

This study aimed to assess cardiovascular risk factors in the offspring of preeclampsia (PE) pregnancies. PubMed, Web of Science, Ovid, and other foreign language databases, as well as SinoMed, China National Knowledge Infrastructure, Wanfang, and China Science and Technology Journal Databases, were searched. The case-control studies on cardiovascular risk factors in the offspring of PE pregnancies from 1 January 2010 to 31 December 2019 were collected. A random-effects model or a fixed-effects model was used, and RevMan 5.3 software was used for meta-analysis to determine the OR value and 95%CI of each cardiovascular risk factor. A total of 16 documents were included in this research, all of which were case-control studies, with a total of 4046 cases in the experimental group and 31,505 in the control group. The meta-analysis that was conducted demonstrated that SBP [MD = 1.51, 95%CI (1.15, 1.88)] and DBP [MD = 1.90, 95%CI (1.69, 2.10)] values in the PE pregnancy offspring group presented an elevation relative to the non-PE pregnancy offspring group. The total cholesterol value in the PE pregnancy offspring group presented an elevation relative to the non-PE pregnancy offspring group [MD = 0.11, 95%CI (0.08, 0.13)]. The low-density lipoprotein cholesterol value in the PE pregnancy offspring group was comparable to that in the non-PE pregnancy offspring group [MD = 0.01, 95%CI (-0.02, 0.05)]. The high-density lipoprotein cholesterol value in the PE pregnancy offspring group presented an elevation relative to the non-PE pregnancy offspring group [MD = 0.02, 95%CI (0.01, 0.03)]. The non-HDL cholesterol value in the PE pregnancy offspring group presented an elevation relative to the non-PE pregnancy offspring group [MD = 0.16, 95%CI (0.13, 0.19)]. The triglycerides [MD = -0.02, 95%CI (-0.03, -0.01)] and glucose [MD = -0.08, 95%CI (-0.09, -0.07)] values in the PE pregnancy offspring group presented a depletion relative to the non-PE pregnancy group. The insulin value in the PE pregnancy offspring group presented a depletion relative to the non-PE pregnancy offspring group [MD = -0.21, 95%CI (-0.32, -0.09)]. The BMI value in the PE pregnancy offspring group presented an elevation relative to the non-PE pregnancy offspring group [MD = 0.42, 95%CI (0.27, 0.57)]. In conclusion, dyslipidemia, elevated blood pressure, and increased BMI occur postpartum with PE, all of which are risk factors for cardiovascular diseases.

Abstract 069: Methylation Of The Androgen Receptor In White Adipose Tissue Contributes To Female Obesity And Hypertension In BPH/5, A Model Of Superimposed Preeclampsia

Preeclampsia (PE) is a hypertensive disorder of pregnancy that occurs in 10% of women with obesity. The effects of PE on offspring are chronic with increased incidence of cardiometabolic disease into adulthood. We hypothesize that a maternal obesogenic environment plays a role in pregnancy outcomes and offspring cardiometabolic disease in a sex-dependent manner through epigenetic modifications on the X chromosome. To test our hypothesis, we used the obese BPH/5 female mouse that spontaneously exhibits late-gestational hypertension, fetal growth restriction, and excessive gestational weight gain. BPH/5 offspring have sexually dimorphic cardiometabolic phenotypes with females being hyperphagic, obese, and hypertensive, while males are only hypertensive. BPH/5 dams were pair-fed (PF) to C57 control dams beginning at conception. Male and female BPH/5 offspring were fed an ad libitum (lib) diet until analyses. Whole genome bisulfite sequencing was performed to reveal differentially methylated regions between BPH/5 male and female genomic DNA. BPH/5 PF dams had attenuation of late gestational hypertension. BPH/5 offspring had improved fetal growth and significantly reduced adult female BPH/5 obesity, 14.7% BW and visceral white adipose tissue (WAT) from 1366 to 229.7 mg (n=7-32, p<0.05). Despite detectable levels of serum testosterone (2.04±0.6ng/dL, n=16), serum estrogen in BPH/5 adult females during proestrus is significantly lower than controls (3.3±1 v. 7.3±0.5 pg/mL, n=6, p<0.05). This is associated with hypermethylation of the androgen receptor on the X chromosome in adult BPH/5 females. Because androgen response elements are in the promoter region of the thermogenic marker, uncoupled protein 1 (Ucp1), an interaction has been proposed between sex steroid hormones and WAT energy homeostasis. Ucp1 mRNA expression is significantly increased in PF adult BPH/5 female mice compared to ad lib (n=3, p<0.05). Reduction in the maternal obesogenic environment may play a role in BPH/5 sex-dependent offspring differences via epigenetic modifications of the X chromosome. Future studies are needed to understand the transgenerational methylation of cardiometabolic genes in PE offspring to prevent the lifecycle of disease associated with obesity.

Long-term effects of preeclampsia on metabolic and biochemical outcomes in offspring: What can be expected from a meta-analysis?

The objective of this study is to evaluate the long-term effects of preeclampsia (PE) on metabolic and biochemical outcomes in offspring. We searched PubMed-Medline, Web of Science, and EMBASE from inception to June 2021 for randomized clinical trials, cohort, and case-control studies. Two researchers independently extracted data according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines and assessed possible bias. Rate ratios (RRs) or weighted mean differences (WMDs) were estimated using fixed-effects model or random-effects model if the heterogeneity was high. PE increased offspring risk of obesity (RR 1.45, 95% confident interval [CI] 1.19-1.78) with a mean weighted age of 9.1years, and a higher body mass index from 10years of age (WMD 0.46, 95% CI 0.08-0.83). PE offspring were associated with a higher mean arterial pressure (WMD 1.33, 95% CI 0.42-2.24), systolic blood pressure (WMD 1.93, 95% CI 1.48-2.37), and diastolic blood pressure (WMD 1.13, 95% CI 0.80-1.47) in puberty. However, we uncovered no association between PE and offspring levels of total cholesterol, triglycerides, high-density lipoprotein, low-density lipoprotein, glucose, and insulin in blood with puberty, nor was there an increase in the risk of type 1 diabetes mellitus in PE offspring under 15 years of age (RR 1.07, 95% CI 0.88-1.32). However, PE might be associated with central obesity, hypertension, and type 2 diabetes mellitus of offspring in later life. Offspring of mothers with PE exhibited an increased risk of obesity in childhood and a higher body mass index and blood pressure in puberty, but there were no differences in blood lipids or glucose metabolism in puberty compared to non-PE offspring. PE might be associated with a higher risk for central obesity, hypertension, and type 2 diabetes mellitus of offspring in later life.

Male HELLP pups experience sensorimotor delays and reduced body weight

Offspring of Preeclampsia (PreE) and HELLP Syndrome are at an increased risk of developing neurodevelopmental disorders. In the current study we sought to determine if offspring from experimental models of PreE and HELLP had evidence of early onset neurodevelopmental delay. Offspring from PreE, HELLP and normal pregnant dams were assessed in a battery of sensorimotor tests beginning on postnatal day (PND) 3. Male HELLP offspring showed altered behavior in the surface righting reflex on PND 3 and cliff avoidance task from PND 3–6 relative to other groups. Results suggest that there are sex differences in offspring born to dams with PreE and HELLP.

Decreased Lymphangiogenic Activities and Genes Expression of Cord Blood Lymphatic Endothelial Progenitor Cells (VEGFR3+/Pod+/CD11b+ Cells) in Patient with Preeclampsia.

The abnormal development or disruption of the lymphatic vasculature has been implicated in metabolic and hypertensive diseases. Recent evidence suggests that the offspring exposed to preeclampsia (PE) in utero are at higher risk of long-term health problems, such as cardiovascular and metabolic diseases in adulthood, owing to in utero fetal programming. We aimed to investigate lymphangiogenic activities in the lymphatic endothelial progenitor cells (LEPCs) of the offspring of PE. Human umbilical cord blood LEPCs from pregnant women with severe PE (n = 10) and gestationally matched normal pregnancies (n = 10) were purified with anti-vascular endothelial growth factor receptor 3 (VEGFR3)/podoplanin/CD11b microbeads using a magnetic cell sorter device. LEPCs from PE displayed significantly delayed differentiation and reduced formation of lymphatic endothelial cell (LEC) colonies compared with the LEPCs from normal pregnancies. LECs differentiated from PE-derived LEPCs exhibited decreased tube formation, migration, proliferation, adhesion, wound healing, and 3D-sprouting activities as well as increased lymphatic permeability through the disorganization of VE-cadherin junctions, compared with the normal pregnancy-derived LECs. In vivo, LEPCs from PE showed significantly reduced lymphatic vessel formation compared to the LEPCs of the normal pregnancy. Gene expression analysis revealed that compared to the normal pregnancy-derived LECs, the PE-derived LECs showed a significant decrease in the expression of pro-lymphangiogenic genes (GREM1, EPHB3, VEGFA, AMOT, THSD7A, ANGPTL4, SEMA5A, FGF2, and GBX2). Collectively, our findings demonstrate, for the first time, that LEPCs from PE have reduced lymphangiogenic activities in vitro and in vivo and show the decreased expression of pro-lymphangiogenic genes. This study opens a new avenue for investigation of the molecular mechanism of LEPC differentiation and lymphangiogenesis in the offspring of PE and subsequently may impact the treatment of long-term health problems such as cardiovascular and metabolic disorders of offspring with abnormal development of lymphatic vasculature.

Adolescent Offspring of Preeclamptic Nonhuman Primate Mothers Have Impaired Glucose Tolerance and Proteinuria

Hypertensive pregnancy disorders are the most common pregnancy complication and are a primary cause of maternal and fetal mortality worldwide. Preeclampsia (PE), defined as de novo maternal hypertension and proteinuria in the 2nd or 3rd trimester, is associated with preterm birth and long‐term cardiovascular risk in both mothers and offspring. The African Green Monkey (AGM; Chlorocebus aethiops sabaeus) develops spontaneous preeclampsia and exhibits fetal growth restriction. We hypothesize that PE pregnancies leading to reduced birthweight may increase the risk for impaired renal and metabolic function in offspring. Offspring of normotensive (NT) pregnancies averaged 335.6 ± 9.6g birthweight, while birthweight of offspring born to PE females was 299.4 ± 9.0g, indicating fetal growth restriction (NT n=12; PE n=24; pδ0.05). To assess glucose tolerance, an oral glucose tolerance test (OGTT) was conducted on a subset of offspring at 1–3 years of age. Glucose was fed to a final concentration of 1.75 g/kg bodyweight. Blood glucose was measured by finger stick with standard glucometry prior to the glucose load and at 15, 30, 60, 90, and 120 minutes post glucose load. Fasting blood glucose was similar between NT and PE juveniles (NT n=9, 77.7 ± 8.4 mg/dl; PE n=11, 82.2 ± 7.6 mg/dl; p>0.05). Blood glucose of NT juveniles peaked at 15 minutes (141.7 ± 18.9mg/dl) and subsequently decreased. In contrast, PE juveniles showed a biphasic glucose response, first peaking at 15 minutes (132 ± 13 mg/dl) and again at 60 minutes (149.4 ± 14.1 mg/dl). The area under the curve of the OGTT was used as an index of glucose tolerance. Glucose tolerance of PE juveniles was impaired compared to NT juveniles (NT n=9, 10994 ± 1390 min*mg/dl; PE n=11, 14831 ± 5761 min*mg/dl; pδ0.05). To monitor water intake and urine flow, juveniles were individually housed (NT n=9; PE n=10). After an acclimation period of 1 week, water intake and urine flow were measured for 3 consecutive days. Urinary protein excretion was greater in PE offspring (NT 152.0 ± 61.7 mg/day vs. PE 354.7 ± 55.8 mg/day; pδ0.05). Sodium excretion was similar between groups (NT 16.10 ± 3.2 mmol/day; PE 18.96 ± 2.9 mmol/day; p>0.05). However, potassium excretion was greater in PE offspring (6.19 ± 0.8 mmol/day vs. NT 2.70 ± 0.9 mmol/day; pδ0.05). Plasma creatinine was similar between offspring of NT and PE females (NT 1.74 ± 0.2 mg/dl; PE 1.65 ± 0.1 mg/dl; p>0.05). An individual with the lowest birth weight of the PE cohort (228.5g vs. mean 314.1 ± 14g) had the highest creatinine level (2.38 mg/dl vs. mean 1.65 ± 0.1 mg/dl) and elevated protein excretion (504.6 mg/day vs. mean 378.5 ± 74.7 mg/day). PE in AGMs is associated with fetal growth restriction resulting in low birthweights. Juveniles born to PE females showed impaired glucose tolerance, proteinuria, and kaliuresis. Exposure to PE in utero may predispose offspring to impaired renal and metabolic function in early adolescence. Continued monitoring of current PE juveniles and phenotyping of 2019 offspring will further assess the influence of maternal pregnancy phenotype on adolescent markers of renal and metabolic impairment.Support or Funding InformationThis work was supported by research funds from Primate Plus, LLC.

Perinatal Micro-Bleeds and Neuroinflammation in E19 Rat Fetuses Exposed to Utero-Placental Ischemia.

Offspring of preeclampsia patients have an increased risk of developing neurological deficits and cognitive impairment. While low placental perfusion, common in preeclampsia and growth restriction, has been linked to neurological deficits, a causative link is not fully established. The goal of this study was to test the hypothesis that placental ischemia induces neuroinflammation and micro-hemorrhages in utero. Timed-pregnant Sprague Dawley rats were weight-matched for sham surgery (abdominal incision only) or induced placental ischemia (surgical reduction of utero-placental perfusion (RUPP)); n = 5/group on gestational day 14. Fetal brains (n = 1–2/dam/endpoint) were collected at embryonic day (E19). Placental ischemia resulted in fewer live fetuses, increased fetal demise, increased hematocrit, and no difference in brain water content in exposed fetuses. Additionally, increased cerebral micro-bleeds (identified with H&E staining), pro-inflammatory cytokines: IL-1β, IL-6, and IL-18, eotaxin (CCL11), LIX (CXCL5), and MIP-2 (CXCL2) were observed in RUPP-exposed fetuses. Microglial density in the sub-ventricular zone decreased in RUPP-exposed fetuses, with no change in cortical thickness. Our findings support the hypothesis that exposure to placental ischemia contributes to microvascular dysfunction (increased micro-bleeds), fetal brain inflammation, and reduced microglial density in proliferative brain areas. Future studies will determine whether in utero abnormalities contribute to long-term behavioral deficits in preeclampsia offspring through impaired neurogenesis regulation.

An alternative splicing variant of mineralocorticoid receptor discovered in preeclampsia tissues and its effect on endothelial dysfunction.

The pathophysiology of preeclampsia (PE) remains unclear. PE spiral artery remodeling dysfunction and PE offspring cardiovascular future development has been a worldwide concern. We collected placental and umbilical artery samples from nor-motensive and PE pregnancies. Mineralocorticoid receptor (MR) and its alternative splicing variant (ASV) expression and their biological effects on PE were examined. An MR ASV was found to be highly expressed in all PE samples and slightly expressed in about half of the normotensive samples (umbilical artery, ~57.58%; placenta, ~36.84%). The MR ASV expression was positively associated with blood pressure in both groups. The MR ASV protein changed the aldosterone-induced expression pattern of MR target genes related to ion exchanges and cell signaling pathways. The MR ASV can also impair the proliferation, migration, and tube formation ability of endothelial cells. These findings indicate that MR ASV in PE placenta plays a pathogenic role in PE pathophysiology, especially in endothelial dysfunction, and the existence of the MR ASV in PE umbilical artery provides a new direction in the study of PE offspring with increased risk of cardiovascular diseases.

Hypermethylation of delta-like homolog 1/maternally expressed gene 3 loci in human umbilical veins: insights into offspring vascular dysfunction born after preeclampsia.

Increasing epidemiological studies have confirmed the association between maternal preeclampsia and elevated blood pressure in their offspring. Though case-control or cohort studies have demonstrated long-term outcomes for the offspring of preeclampsia, it is still a question that how these changes were caused by genetic reasons or by preeclampsia itself. In our study, we explored the potential epigenetic regulation of delta-like homolog 1-maternally expressed gene 3 (DLK1-MEG3) region in human umbilical vein endothelial cells (HUVECs), and its connection with endothelium-derived factors. We recruited 58 singletons born with spontaneous conception (control group) and 67 singletons whose mother with preeclampsia (preeclampsia group), and detected the infants' blood pressure and growth development index. To explore the potential mechanism, we did real-time PCR to test DLK1-MEG3 imprinted genes and endothelium-derived factors. ELISA confirmed the protein secretion changes between two groups. In addition to confirm epigenetic alteration in preeclampsia HUVEC, we performed pyro-sequencing to detect methylation status of two different methylation regions: intergenic differential methylation region (IG-DMR) and MEG3 DMR which control the expression of DLK1 and MEG3. Furthermore, Person correlation was used to make sure the association of methylation alteration of IG-DMR and endothelium-derived factors. In our study, we found that DBP was significantly lower in preeclampsia offspring who born over 34 weeks compared with normal offspring (53.59 ± 1.38 vs. 59.9 ± 1.40 mmHg, P < 0.01), which leads to higher pulse pressure difference. Quantitative real-time PCR showed that imprinted gene DLK1 level significantly increased and MEG3 level decreased in HUVEC of preeclampsia group compared with control group, accompanying with lower expression of endothelial nitric oxide synthase and vascular endothelial growth factor (VEGF), higher expression of endothelin-1 (ET1), which are close related with vascular endothelial function. Meanwhile, ELISA assay of ET1, nitrite, VEGF were consistent with real-time results. Furthermore, abnormal expression of DLK1-MEG3 expression was caused by hypermethylation status of IG-DMR, And methylation status of IG-DMR highly correlated with ET1 concentration and nitrate concentration, these might be one of the mechanisms for impaired endothelial function (coefficient = 0.5806, P = 0.0115; coefficient = -0.4883, P = 0.0398). Our results demonstrated that altered expression of imprinted genes DLK1 and MEG3 were caused by hypermethylation of IG-DMR in HUVEC of preeclampsia group, accompanied by lower secretion of nitrite, VEGF, and higher secretion of ET1. It might be one potential mechanism for higher risk of cardiovascular disease in preeclampsia offspring later in life.

Abstract P310: Hypermethylation of Dlk1-meg3 Loci in Human Umbilical Veins: Insights Into Offspring Vasculardysfunction Born After Pre-Eclampsia

Increasing epidemiological studies have confirmed the association between maternal pre-eclampsia and elevated blood pressure in their offspring. In our study, we explored the potential epigenetic regulation of Dlk1-Meg3 region in human umbilical vein endothelial cells, and its connection with endothelium-derived factors. We recruited 58 singletons born spontaneously and 67 singletons born with pre-eclampsia during 2016 to detect blood pressure and growth development index, and found that diastolic blood pressure was significantly lower in pre-eclampsia offspring who born over 34 weeks compared to normal offspring (53.59±1.38mmHg VS 59.9±1.40mmHg, P&lt;0.01), which leads to higher pulse pressure difference. RT-qPCR showed that imprinted gene Dlk1 level significantly increased and Meg3 level decreased in HUVECs than that in control group, accompanying with lower expression of endothelial nitric oxide synthase(eNOS) and vascular endothelial growth factor (VEGF) , higher expression of endothelin-1 (ET1), which are close related with vascular endothelial function. Meanwhile, ELISA assay of ET1, Nitrite, VEGF were consistent with Real-time results. Besides, we used pyrosequencing to find that abnormal expression of Dlk1-Meg3 expression were caused by hyper-methylation status of IG-DMR. And methylation status of IG-DMR highly correlated with ET1 concentration and Nitrate concentration, these might be one of the mechanisms for impaired endothelial function (Coeffient=0.5806, P=0.0115; Coeffient=-0.4883, P=0.0398). Our results demonstrated that altered expression of imprinted gene Dlk1 and Meg3 were caused by hypermethylation of IG-DMR in pre-eclampsia HUVECs, accompanied by lower secretion of nitrite, VEGF, and higher secretion of ET1. It might be one potential mechanism for higher risk of cardiovascular disease in pre-eclampsia offspring later in life.

Preeclampsia Downregulates MicroRNAs in Fetal Endothelial Cells: Roles of miR-29a/c-3p in Endothelial Function.

Preeclampsia is a leading cause of fetal and maternal morbidity and mortality during pregnancy. Although the etiology of preeclampsia is unknown, preeclampsia offspring have increased risks of developing cardiovascular disorders in adulthood, implicating that preeclampsia programs fetal vasculature in utero. We hypothesize that preeclampsia alters expression profiles of endothelial microRNAs (miRNAs) in fetal endothelial cells and disturbs the vascular endothelial growth factor A (VEGFA)- and fibroblast growth factor 2 (FGF2)-induced endothelial function. Unpassaged (P0) human umbilical vein endothelial cells (HUVECs) were isolated immediately after cesarean-section delivery from normotensive (NT) and preeclamptic (PE) pregnancies. Differentially expressed miRNAs between P0-HUVECs from NT and PE pregnancies were identified using a miRNA polymerase chain reaction (PCR) array and confirmed using reverse transcription quantitative PCR. To determine the function of these differentially expressed miRNAs, miRNAs of interest were knocked down in NT-HUVECs following by cell functional assays. Sixteen miRNAs, including miR-29a/c-3p, were downregulated in P0-HUVECs from the PE group compared with the NT group. Bioinformatics analysis predicted the PI3K-v-akt murine thymoma viral oncogene homolog 1 (AKT) signaling pathway was dysregulated in P0-HUVECs from the PE group, which was associated with the miR-29a/c-3p downregulation. We further demonstrated that miR-29a/c-3p knockdown inhibited the VEGFA- and FGF2-induced endothelial migration as well as FGF2-induced AKT1 phosphorylation in HUVECs. However, miR-29a/c-3p knockdown did not alter the extracellular signal-regulated kinase 1/2 phosphorylation, cell proliferation, and endothelial monolayer integrity in response to VEGFA and FGF2 in HUVECs. Preeclampsia-downregulated miR-29a/c-3p may impair fetal endothelial function by disturbing the FGF2-activated PI3K-AKT signaling pathway, hence inhibiting endothelial cell migration.

Evidence for central hypercortisolism and elevated blood pressure in adolescent offspring of mothers with pre-eclampsia.

Maternal total and free cortisol concentrations are reduced in pre-eclampsia (PE) and gestational hypertension (GH). However, the effect of this on the hypothalamic-pituitary-adrenal (HPA) axis function in the offspring is unknown. We examined the basal HPA axis activity in adolescent offspring of mothers with pre-pregnancy hypertension/GH/PE. A total of 1182 participants (mean age 17·1 years) recruited from the Western Australian Pregnancy Cohort (Raine) Study provided fasting morning blood samples for basal HPA axis and concomitant clinical assessments, including blood pressure. Plasma ACTH, total cortisol, corticosteroid-binding globulin (CBG) and free cortisol calculated by Coolens' equation were measured from the blood samples collected at home before 10:00 am. Total plasma cortisol (689 ± 153 nmol/l vs 583 ± 172 nmol/l, P = 0·024), ACTH (15·5 ± 13 pmol/l vs 10·8 ± 5·1 pmol/l, P = 0·040) and calculated free cortisol (52 ± 21 nmol/l vs 42 ± 22 nmol/l, P = 0·052) were higher in the PE offspring than in controls. The pre-pregnancy hypertension group had evidence of a lower ACTH/plasma free cortisol ratio (0·22 vs 0·33 P = 0·020) and lower CBG (713 nmol/l vs 821 nmol/l, P = 0·004) compared with controls. Systolic blood pressure was elevated in the GH/PE group compared with controls (120 mmHg vs 116 mmHg, P = 0·006). Hypothalamic-pituitary-adrenal axis activity is increased in the adolescent offspring of mothers with pre-eclampsia. This may be an adaptation resulting from the reduced maternal cortisol during foetal life. The resulting mild hypercortisolism may have implications for long-term health outcomes and warrants further investigation.

Differential proteomic analysis of umbilical artery tissue from preeclampsia patients, using iTRAQ isobaric tags and 2D nano LC-MS/MS.

Increasing evidence suggests that the children who were exposed to preeclampsia in utero have an increased cardiovascular risk, and vascular dysfunction has been found in some children born of preeclampsia. However, the mechanism remains largely unknown. In this study, we identified 1521 non-redundant proteins, and 1496 of these were quantified. Further analysis identified 53 differentially expressed proteins in the umbilical artery from preeclampsia patients; 22 proteins were up-regulated and 31 proteins were down-regulated. Some of these differentially expressed proteins have been shown to play important roles in cardiovascular system development. Our results provide new insights into the potential mechanisms underlying the changed blood pressure of offspring of mothers with preeclampsia, and, the elevation of their risk of cardiovascular abnormality in later life.

Mechanisms and Drug Therapy of Pulmonary Hypertension at High Altitude

Pulmonary vasoconstriction represents a physiological adaptive mechanism to high altitude. If exaggerated, however, it is associated with important morbidity and mortality. Recent mechanistic studies using short-term acute high altitude exposure have provided insight into the importance of defective vascular endothelial and respiratory epithelial nitric oxide (NO) synthesis, increased endothelin-1 bioavailability, and overactivation of the sympathetic nervous system in causing exaggerated hypoxic pulmonary hypertension in humans. Based on these studies, drugs that increase NO bioavailability, attenuate endothelin-1 induced pulmonary vasoconstriction, or prevent exaggerated sympathetic activation have been shown to be useful for the treatment/prevention of exaggerated pulmonary hypertension during acute short-term high altitude exposure. The mechanisms underpinning chronic pulmonary hypertension in high altitude dwellers are less well understood, but recent evidence suggests that they differ in some aspects from those involved in short-term adaptation to high altitude. These differences have consequences for the choice of the treatment for chronic pulmonary hypertension at high altitude. Finally, recent data indicate that fetal programming of pulmonary vascular dysfunction in offspring of preeclampsia and children generated by assisted reproductive technologies represents a novel and frequent cause of pulmonary hypertension at high altitude. In animal models of fetal programming of hypoxic pulmonary hypertension, epigenetic mechanisms play a role, and targeting of these mechanisms with drugs lowers pulmonary artery pressure. If epigenetic mechanisms also are operational in the fetal programming of pulmonary vascular dysfunction in humans, such drugs may become novel tools for the treatment of hypoxic pulmonary hypertension.

PP080. Blood pressure in the offspring of experimental preeclamptic and normotensive baboon pregnancies

Experimental manipulation of the maternal environment in animal models has assisted with our understanding of the mechanisms contributing to fetal programming. Evidence suggests that individuals who experience a suboptimal intrauterine milieu have an increased risk of developing disease later in life. Preeclampsia is a complication of pregnancy known to alter the fetal environment. Such alterations lead to programming of the fetus for subsequent susceptibility to cardiovascular disease, including hypertension. Studies indicate that offspring from women with hypertensive disorders of pregnancy are at an increased risk of cardiovascular complications later in life. To investigate whether offspring of experimental preeclamptic baboon pregnancies have higher blood pressure compared with offspring of their experimental controls and those of normotensive pregnancies. This is a pilot study to assess the feasibility of measuring health outcomes and risk factors for experimental preeclampsia offspring. We have successfully developed two models of preeclampsia in the baboon (Papio hamadryas) through induction of uteroplacental ischemia in late pregnancy and TNFα infusion mid pregnancy. Systolic and diastolic blood pressure (SBP, DBP) were measured in baboon offspring from experimental preeclamptic (EPE, n=4), experimental preeclamptic control (EPE control, n=4) and normotensive pregnancies (Normal, n=12) using indirect sphygmomanometry (first and fourth Korotkoff sounds recorded). Each measurement was taken three times under identical anaesthetic and environmental conditions. Data are reported as the average ± standard deviation. A generalized linear model was applied to the data and adjusted for age and sex. There was no significant difference in SBP of offspring from EPE (97.3±7.2mm Hg, P=0.21) or EPE control (108.4±7.3mm Hg, P=0.16) when compared with offspring of normotensive pregnancies (102.6±7.3mm Hg). Similarly, there was no difference in DBP of offspring from EPE (67.5±15.4 mm Hg, P=0.72) or EPE control (61.5±15.7mm Hg, P=0.79) compared with normotensive offspring (63.9±16.7mm Hg). There was a significant difference in SBP and DBP of young (<5yrs) compared to older (⩾5yrs) animals (SBP: 96.4±7.9 versus 109.1±7.5mm Hg, P=0.003; DBP: 54.3±17.2 versus 74.4±16.4mm Hg, P=0.009). There were no differences in SBP or DBP between male and female offspring (102.1±7.7 versus 103.4±8.3mm Hg, P=0.70; 63.9±16.8 versus 64.8±18.4mm Hg, P=0.90 respectively). This study has shown that offspring from experimental preeclamptic pregnancies survive and are able to undergo long-term testing of blood pressure. There does not appear to be any significant differences in blood pressure among EPE offspring and their controls. However, the opportunity to investigate offspring over an extended period of time is feasible. This will enable us to examine other parameters that affect BP of experimental preeclampsia offspring.

Response to Letters Regarding Article, “Pulmonary and Systemic Vascular Dysfunction in Young Offspring of Mothers With Preeclampsia”

We thank Lazdam et al and Yuan et al for their interesting comments on our study.1 Lazdam et al point out that in our study, birth weight in offspring of mothers with preeclampsia was significantly lower than in controls, and suggest that the vascular impairment in offspring was caused by a combination of the independent effects of preeclampsia and intrauterine growth restriction rather than by preeclampsia per se. To test this hypothesis, we performed a subgroup analysis of 15 offspring of mothers with preeclampsia and 15 controls matched for birth weight (3080±291 versus 3077±398 g; P =0.98). We found that the difference in flow-mediated dilation between birth-weight-matched offspring of preeclampsia and controls (6.4%±1.3% versus 8.9%±1.2%; P <0.0001) tended to be even larger …

055 Elevated blood pressure in offspring born to hypertensive pregnancy: is endothelial dysfunction the underlying vascular mechanism?

<h3>Background</h3> Mothers with preeclampsia exhibit endothelial damage proportional to the severity of the condition. Higher blood pressure had been observed in their offspring and we hypothesised that this is a result of endothelial dysfunction also being present in the infant. This dysfunction should be greatest in those born premature due to severe preeclampsia and, as prematurity per se is associated with hypertension, we explored whether the underlying vascular phenotype differs from that observed when prematurity is not related to maternal vascular dysfunction. <h3>Methods</h3> We studied 99 young adults aged 20–30. Seventy-one subjects were born preterm to a hypertensive (27%) or a normotensive pregnancy (73%), and 28 term controls born to uncomplicated pregnancies. Subjects underwent measurements of peripheral (BP) and central blood pressures (cBP). Endothelial dependent (FMD) and endothelial-independent brachial artery responses were assessed by ultrasound. Aortic stiffness was measured by pulse wave velocity (PWV) using applanation tonometry. <h3>Results</h3> Offspring born premature either to hypertensive or normotensive pregnancy displayed significantly elevated peripheral (DBP 71.79±7.37, 71.61±6.52 vs 64.92±7.05, ANOVA p=0.0003 and MAP 87.93±7.61, 88.07±6.9 vs 81.62±8.06, ANOVA p=0.002) and central blood pressures (cSBP 115.96±10.86, 115.78±10.55 vs 96.71±9.86, ANOVA p&lt;0.0001, cMAP 84.92±7.0, 84.13±8.9 vs 76.24±7.96, ANOVA p=0.0009 and cPPBP 46.56±8.63, 46.94±10.27 vs 30.71±4.82, ANOVA p&lt;0.0001) compared to controls born at term. However, the offspring of hypertensive pregnancy had a distinct vascular phenotype with 40% lower FMD compared to subjects born at term to a normotensive pregnancy (4.25±4.02 vs7.27±5.12, p=0.035) and increased cIMT (0.52±0.04 vs 0.48±0.06, p=0.04). Whereas, those born premature to a normotensive pregnancy had normal endothelial responses but differences in PWV compared to term controls (5.92±0.84 vs 5.56±1.09, p=0.035). <h3>Conclusion</h3> Prematurity is associated with elevated blood pressure in later life. In offspring of pregnancies complicated by preeclampsia or gestational hypertension, endothelial dysfunction is the predominant vascular phenotype. The findings direct attention towards endothelial dysfunction as a potential target for primary prevention in offspring of pre-eclampsia.