The effect of pre-eclampsia-like syndrome induced by L-NAME on learning and memory and hippocampal glucocorticoid receptor expression: A rat model

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

OBJECTIVES

Gamete 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.

METHODS

Nω-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.

RESULTS

PE 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.

CONCLUSION

These 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.

Salidroside prevents gestational hypertension-induced impairment of offspring learning and memory via Wnt/Skp2 pathway

BACKGROUND

Salidroside (Sal) has been found to protect against multiple impairments caused by diabetes, and we designed this study to investigate the effect of Sal on gestational hypertension (GHP)-induced impairment of offspring learning and memory.

METHODS

We established a GHP rat model by intraperitoneal injection of NG-nitro-L-arginine methyl ester (L-NAME), and treated with Sal by daily gavage. We used Morris Water Maze test to evaluate the learning and memory ability of offspring rats. HE staining was used to measured the pathological changes in hippocampus of offspring. Immunohistochemistry, cellular immunofluorescence and western blot were used to detect the protein expression.

RESULTS

The learning and memory abilities of GHP offspring rats were significantly lower than those of normal rat offspring, while Sal treatment could significantly improve the learning and memory abilities of GHP offspring rats. HE staining did not reveal pathological differences in the hippocampus of normal rats, GHP rats and Sal-treated GHP offspring rats. However, Sal treatment can significantly increase the expression of Wnt1 and Skp2 protein, and decrease the expression of P27kiwf and P21waf1 protein in the hippocampus of GHP offspring rats. In vitro, Sal significantly promoted the proliferation and differentiation on neural stem cell, while Wnt1 knockdown could reverse these promotions by Sal. In the hippocampus of GHP offspring rats, Sal treatment significantly increased the expression of Tuj1, SOX2, Ki67 and DCX protein.

CONCLUSION

Salidroside significantly improves the learning and memory impairment of offspring caused by GHP, and its mechanism may be related to the fact that Salidroside promotes the proliferation and differentiation of neural stem cells by activating the Wnt1/Skp2 signaling pathway.

Maternal immune suppression during pregnancy does not prevent abnormal behavior in offspring

BACKGROUND

Offspring of hypertensive disorders of pregnancy are at an increased risk of developing neurodevelopmental and neurobehavioral disorders compared to offspring from non-affected pregnancies. Using rodent models of Preeclampsia (PreE; new onset of hypertension after 20 weeks gestation) and HELLP (hemolysis, elevated liver enzymes, and low platelets), we studied the behavioral outcome of their offspring in adolescence.

METHODS

A subset of dams received Orencia, a T-cell activation inhibitor, as T cells have been associated with the induction of hypertension and inflammation during pregnancy. We hypothesized that offspring from hypertensive dams would experience adverse behavioral outcomes in social, cognitive, locomotor, and anxiety tests, and offspring from dams treated with Orencia would demonstrate less adverse behaviors.

RESULTS

Male offspring of PreE + Orencia dams (p < 0.05) and female offspring from HELLP + Orencia dams (p < 0.05) spent more time playing compared to normal pregnant offspring. All offspring from hypertensive and Orencia-treated dams performed worse on the Barnes Maze test compared to normal pregnant. We also measured adult (postnatal day > 60) myelin basic protein (MBP) and NeuN expression in both the prefrontal cortex and hippocampus. In the hippocampus and prefrontal cortex, there was no difference in expression of either MBP or NeuN in all groups regardless of sex.

CONCLUSION

The results from this study suggest that offspring of hypertensive disorders of pregnancy have behavioral changes, specifically cognitive differences. This study has shown that there is a sex dependent difference in offspring neurobehavioral development, influenced in part by the type of hypertensive disorder of pregnancy, and alterations in the maternal immune system.

Neurodevelopmental Disruptions in Children of Preeclamptic Mothers: Pathophysiological Mechanisms and Consequences

Preeclampsia (PE) is a multisystem disorder characterized by elevated blood pressure in the mother, typically occurring after 20 weeks of gestation and posing risks to both maternal and fetal health. PE causes placental changes that can affect the fetus, particularly neurodevelopment. Its key pathophysiological mechanisms encompass hypoxia, vascular and angiogenic dysregulation, inflammation, neuronal and glial alterations, and disruptions in neuronal signaling. Animal models indicate that PE is correlated with neurodevelopmental alterations and cognitive dysfunctions in offspring and in humans, an association between PE and conditions such as cerebral palsy, autism spectrum disorder, attention deficit hyperactivity disorder, and sexual dimorphism has been observed. Considering the relevance for mothers and children, we conducted a narrative literature review to describe the relationships between the pathophysiological mechanisms behind neurodevelopmental alterations in the offspring of PE mothers, along with their potential consequences. Furthermore, we emphasize aspects pertinent to the prevention/treatment of PE in pregnant mothers and alterations observed in their offspring. The present narrative review offers a current, complete, and exhaustive analysis of (i) the pathophysiological mechanisms that can affect neurodevelopment in the children of PE mothers, (ii) the relationship between PE and neurological alterations in offspring, and (iii) the prevention/treatment of PE.

Reduced Brain Cortex Angiogenesis in the Offspring of the Preeclampsia-Like Syndrome

BACKGROUND

Children from pregnancies affected by preeclampsia have an increased risk of cognitive and behavioral alterations via unknown pathophysiology. We tested the hypothesis that preeclampsia generated reduced brain cortex angiogenesis in the offspring.

METHODS

The preeclampsia-like syndrome (PELS) mouse model was generated by administering the nitric oxide inhibitor NG-nitroarginine methyl ester hydrochloride. Confirmatory experiments were done using 2 additional PELS models. While in vitro analysis used mice and human brain endothelial cells exposed to serum of postnatal day 5 pups or umbilical plasma from preeclamptic pregnancies, respectively.

RESULTS

We report significant reduction in the area occupied by blood vessels in the motor and somatosensory brain cortex of offspring (postnatal day 5) from PELS compared with uncomplicated control offspring. These data were confirmed using 2 additional PELS models. Furthermore, circulating levels of critical proangiogenic factors, VEGF (vascular endothelial growth factor), and PlGF (placental growth factor) were lower in postnatal day 5 PELS. Also we found lower VEGF receptor 2 (KDR [kinase insert domain-containing receptor]) levels in mice and human endothelial cells exposed to the serum of postnatal day 5 PELS or fetal plasma of preeclamptic pregnancies, respectively. These changes were associated with lower in vitro angiogenic capacity, diminished cell migration, larger F-actin filaments, lower number of filopodia, and lower protein levels of F-actin polymerization regulators in brain endothelial cells exposed to serum or fetal plasma of offspring from preeclampsia.

CONCLUSIONS

Offspring from preeclampsia exhibited diminished brain cortex angiogenesis, associated with lower circulating VEGF/PlGF/KDR protein levels, impaired brain endothelial migration, and dysfunctional assembly of F-actin filaments. These alterations may predispose to structural and functional alterations in long-term brain development.

Altered offspring neurodevelopment in an L-NAME-induced preeclampsia rat model

Introduction

To investigate the mechanism underlying the increased risk of subsequent neurodevelopmental disorders in children born to mothers with preeclampsia, we evaluated the neurodevelopment of offspring of a preeclampsia rat model induced by the administration of N-nitro-L-arginine methyl ester (L-NAME) and identified unique protein signatures in the offspring cerebrospinal fluid.

Methods

Pregnant rats received an intraperitoneal injection of L-NAME (250 mg/kg/day) during gestational days 15-20 to establish a preeclampsia model. Behavioral experiments (negative geotaxis, open-field, rotarod treadmill, and active avoidance tests), immunohistochemistry [anti-neuronal nuclei (NeuN) staining in the hippocampal dentate gyrus and cerebral cortex on postnatal day 70], and proteome analysis of the cerebrospinal fluid on postnatal day 5 were performed on male offspring.

Results

Offspring of the preeclampsia dam exhibited increased growth restriction at birth (52.5%), but showed postnatal catch-up growth on postnatal day 14. Several behavioral abnormalities including motor development and vestibular function (negative geotaxis test: p < 0.01) in the neonatal period; motor coordination and learning skills (rotarod treadmill test: p = 0.01); and memory skills (active avoidance test: p < 0.01) in the juvenile period were observed. NeuN-positive cells in preeclampsia rats were significantly reduced in both the hippocampal dentate gyrus and cerebral cortex (p < 0.01, p < 0.01, respectively). Among the 1270 proteins in the cerebrospinal fluid identified using liquid chromatography-tandem mass spectrometry, 32 were differentially expressed. Principal component analysis showed that most cerebrospinal fluid samples achieved clear separation between preeclampsia and control rats. Pathway analysis revealed that differentially expressed proteins were associated with endoplasmic reticulum translocation, Rab proteins, and ribosomal proteins, which are involved in various nervous system disorders including autism spectrum disorders, schizophrenia, and Alzheimer's disease.

Conclusion

The offspring of the L-NAME-induced preeclampsia model rats exhibited key features of neurodevelopmental abnormalities on behavioral and pathological examinations similar to humans. We found altered cerebrospinal fluid protein profiling in this preeclampsia rat, and the unique protein signatures related to endoplasmic reticulum translocation, Rab proteins, and ribosomal proteins may be associated with subsequent adverse neurodevelopment in the offspring.

Environmental Enrichment Protects Offspring of a Rat Model of Preeclampsia from Cognitive Decline

Preeclampsia affects 5-7% of all pregnancies and contributes to adverse pregnancy and birth outcomes. In addition to the short-term effects of preeclampsia, preeclampsia can exert long-term adverse effects on offspring. Numerous studies have demonstrated that offspring of preeclamptic women exhibit cognitive deficits from childhood to old age. However, effective ways to improve the cognitive abilities of these offspring remain to be investigated. The aim of this study was to explore whether environmental enrichment in early life could restore the cognitive ability of the offspring of a rat model of preeclampsia and to investigate the cellular and molecular mechanisms by which EE improves cognitive ability. L-NAME was used to establish a rat model of preeclampsia. The spatial learning and memory abilities and recognition memory of 56-day-old offspring were evaluated by the Morris water maze and Novel object recognition (NOR) task. Immunofluorescence was performed to evaluate cell proliferation and apoptosis in the DG region of the hippocampus. qRT-PCR was performed to examine the expression levels of neurogenesis-associated genes, pre- and postsynaptic proteins and inflammatory cytokines. An enzyme-linked immune absorbent assay was performed to evaluate the concentration of vascular endothelial growth factor (VEGF) and inflammatory cytokines in the hippocampus. The administration of L-NAME led to increased systolic blood pressure and urine protein levels in pregnant rats. Offspring in the L-NAME group exhibited impaired spatial learning ability and memory as well as NOR memory. Hippocampal neurogenesis and synaptic plasticity were impaired in offspring from the L-NAME group. Furthermore, cell apoptosis in the hippocampus was increased in the L-NAME group. The hippocampus was skewed to a proinflammatory profile, as shown by increased inflammatory cytokine levels. EE improved the cognitive ability of offspring in the L-NAME group and resulted in increased hippocampal neurogenesis and synaptic protein expression levels and decreased apoptosis and inflammatory cytokine levels. Environmental enrichment resolves cognitive impairment in the offspring of a rat model of preeclampsia by improving hippocampal neurogenesis and synaptic plasticity and normalizing the apoptosis level and the inflammatory balance.

Reliability of Rodent and Rabbit Models in Preeclampsia Research

In vivo studies on the pathology of gestation, including preeclampsia, often use small mammals such as rabbits or rodents, i.e., mice, rats, hamsters, and guinea pigs. The key advantage of these animals is their short reproductive cycle; in addition, similar to humans, they also develop a haemochorial placenta and present a similar transformation of maternal spiral arteries. Interestingly, pregnant dams also demonstrate a similar reaction to inflammatory factors and placentally derived antiangiogenic factors, i.e., soluble fms-like tyrosine kinase 1 (sFlt-1) or soluble endoglin-1 (sEng), as preeclamptic women: all animals present an increase in blood pressure and usually proteinuria. These constitute the classical duet that allows for the recognition of preeclampsia. However, the time of initiation of maternal vessel remodelling and the depth of trophoblast invasion differs between rabbits, rodents, and humans. Unfortunately, at present, no known animal replicates a human pregnancy exactly, and hence, the use of rabbit and rodent models is restricted to the investigation of individual aspects of human gestation only. This article compares the process of placentation in rodents, rabbits, and humans, which should be considered when planning experiments on preeclampsia; these aspects might determine the success, or failure, of the study. The report also reviews the rodent and rabbit models used to investigate certain aspects of the pathomechanism of human preeclampsia, especially those related to incorrect trophoblast invasion, placental hypoxia, inflammation, or maternal endothelial dysfunction.

Combined melatonin and adrenocorticotropic hormone treatment attenuates N-methyl-d-aspartate-induced infantile spasms in a rat model by regulating activation of the HPA axis

Infantile spasms (IS) is a serious epileptic syndrome that frequently occurs in infancy. Adrenocorticotropic hormone (ACTH) is generally the first-line treatment for IS; however, side effects limit its application. Melatonin (MT) has been used in clinical treatment for sleep disorders with only minor side effects. Further, MT was shown to be a powerful anticonvulsant in an animal model of epilepsy. In this research, we aimed to compare the anticonvulsant efficacy of ACTH and/or MT for treatment of IS and explore the mechanisms underlying the anticonvulsant activity of MT, using an N-methyl-d-aspartate (NMDA)-induced IS model in neonatal rats following exposure to prenatal stress. Latency to the onset of spasms and the total number of spasms were recorded to assess spasm severity. Treatment with ACTH and/or MT significantly reduced the number of spasms and prolonged the latency period. Additionally, expression of GR-α, HDAC2, BNDF, TrkB, and C-Cbl were significantly increased by induction with NMDA, and this effect was reversed by ACTH and/or MT treatment. Hence, our data suggest that combined ACTH and MT treatment is effective for reducing the number of spasms and increasing the latency period in NMDA rats, by restoring dysregulation of the HPA axis. These findings have the potential to provide a new strategy for the treatment of IS.

Altered offspring neurodevelopment in an arginine vasopressin preeclampsia model

Preeclampsia is a severe gestational hypertensive condition linked to child neuropsychiatric disorders, although underlying mechanisms are unclear. We used a recently developed, clinically relevant animal model of preeclampsia to assess offspring. C57BL/6J mouse dams were chronically infused with arginine vasopressin (AVP) or saline (24 ng/h) throughout pregnancy. Adult offspring were behaviorally tested (Y-maze, open field, rotarod, social approach, and elevated plus maze). Offspring brain was assessed histologically and by RNA sequencing. Preeclampsia-exposed adult males exhibited increased anxiety-like behavior and social approach while adult females exhibited impaired procedural learning. Adult AVP-exposed males had reduced total neocortical volume. Adult AVP-exposed females had increased caudate-putamen volume, increased caudate-putamen cell number, and decreased excitatory synapse density in hippocampal dentate gyrus (DG), CA1, and CA3. At postnatal day 7 (P7), AVP-exposed male and female offspring both had smaller neocortex. At P7, AVP-exposed males also had smaller caudate-putamen volume, while females had increased caudate-putamen volume relative to neocortical size. Similar to P7, E18 AVP-exposed offspring had smaller dorsal forebrain, mainly in reduced intermediate, subventricular, and ventricular zone volume, particularly in males. Decreased volume was not accounted for by cell size or cerebrovascular vessel diameter changes. E18 cortical RNAseq revealed 49 differentially-expressed genes in male AVP-exposed offspring, over-representing cytoplasmic translation processes. In females, 31 genes were differentially-expressed, over-representing collagen-related and epithelial regulation pathways. Gene expression changes in E18 AVP-exposed placenta indicated potential underlying mechanisms. Deficits in behavior and forebrain development in this AVP-based preeclampsia model were distinctly different in males and females, implicating different neurobiological bases.

Preeclampsia may influence offspring neuroanatomy and cognitive function: a role for placental growth factor†

Preeclampsia (PE) is a common pregnancy complication affecting 3-5% of women. Preeclampsia is diagnosed clinically as new-onset hypertension with associated end organ damage after 20 weeks of gestation. Despite being diagnosed as a maternal syndrome, fetal experience of PE is a developmental insult with lifelong cognitive consequences. These cognitive alterations are associated with distorted neuroanatomy and cerebrovasculature, including a higher risk of stroke. The pathophysiology of a PE pregnancy is complex, with many factors potentially able to affect fetal development. Deficient pro-angiogenic factor expression is one aspect that may impair fetal vascularization, alter brain structure, and affect future cognition. Of the pro-angiogenic growth factors, placental growth factor (PGF) is strongly linked to PE. Concentrations of PGF are inappropriately low in maternal blood both before and during a PE gestation. Fetal concentrations of PGF appear to mirror maternal circulating concentrations. Using Pgf-/- mice that may model effects of PE on offspring, we demonstrated altered central nervous system vascularization, neuroanatomy, and behavior. Overall, we propose that development of the fetal brain is impaired in PE, making the offspring of preeclamptic pregnancies a unique cohort with greater risk of altered cognition and cerebrovasculature. These individuals may benefit from early interventions, either pharmacological or environmental. The early neonatal period may be a promising window for intervention while the developing brain retains plasticity.

Exploring the beneficial effects and possible mechanisms of repeated episodes of whole-body hypoxic perconditioning in rat model of preeclampsia

AIM

The study explored the beneficial effects of repeated episodes of whole body hypoxic perconditioning (WHPC) on preeclampsia (PE)-like symptoms in rats.

MATERIAL AND METHODS

PE was induced by administration of L-NAME (75 mg/kg) and WHPC was performed by exposing rats to low O₂ (8%) and normal O₂ of 10 min each in four alternate cycles.

RESULTS

L-NAME induced PE like symptoms in rats along with a decrease in the cystathionine-β-synthase (CBS) activity in the placental tissue, plasma levels of H₂S and NO metabolites in pregnant rats. Two (GD9, GD14) and three episodes (GD9, GD14 and GD18) of WHPC improved PE-like symptoms with an increase in CBS activity and H₂S levels. CBS inhibitor, amino-oxyacetic acid abolished the beneficial effects of three episodes of WHPC; while H₂S donor, 4-methylbenzenecarbothioamide, 4-MBC attenuated PE-like symptoms.

CONCLUSION

WHPC attenuates L-NAME-induced PE-like symptoms due to increase in CBS activity and H₂S-production.

Neurodevelopmental Outcomes of Prenatal Preeclampsia Exposure

Preeclampsia is a dangerous hypertensive disorder of pregnancy with known links to negative child health outcomes. Here, we review epidemiological and basic neuroscience work from the past several decades linking prenatal preeclampsia to altered neurodevelopment. This work demonstrates increased rates of neuropsychiatric disorders [e.g., increased autism spectrum disorder, attention deficit hyperactivity disorder (ADHD)] in children of preeclamptic pregnancies, as well as increased rates of cognitive impairments [e.g., decreased intelligence quotient (IQ), academic performance] and neurological disease (e.g., stroke and epilepsy). We also review findings from multiple animal models of preeclampsia. Manipulation of key clinical preeclampsia processes in these models (e.g., placental hypoxia, immune dysfunction, angiogenesis, oxidative stress) causes various disruptions in offspring, including ones in white matter/glia, glucocorticoid receptors, neuroimmune outcomes, cerebrovascular structure, and cognition/behavior. This animal work implicates potentially high-yield targets that may be leveraged in the future for clinical application.

Lasting Effects of Intrauterine Exposure to Preeclampsia on Offspring and the Underlying Mechanism

Preeclampsia is a common pregnancy complication which can have adverse impact on both mother and baby. In addition to the short term effects, a large body of epidemiological evidence has found preeclampsia can exert long-lasting effects on mother and offspring. Studies suggest that offspring exposed to preeclampsia are at a higher risk of developing cardiovascular, metabolic, and neurological diseases, as well as other diseases. However, studies investigating the underlying mechanism are limited, the exact mechanism still remains unclear. In this study, we will review the epidemiological evidence and studies exploring the mechanism underlying long-term effects of preeclampsia on offspring. Further studies should be targeted at this field so as to implement effective clinical management to prevent the exposed offspring from potential diseases.

Effects of placental growth factor deficiency on behavior, neuroanatomy, and cerebrovasculature of mice

Preeclampsia, a hypertensive syndrome occurring in 3-5% of human pregnancies, has lifelong health consequences for fetuses. Cognitive ability throughout life is altered, and adult stroke risk is increased. One potential etiological factor for altered brain development is low concentrations of proangiogenic placental growth factor (PGF). Impaired PGF production may promote an antiangiogenic fetal environment during neural and cerebrovascular development. We previously reported delayed vascularization of the hindbrain, altered retinal vascular organization, and less connectivity in the circle of Willis in Pgf^-/- mice. We hypothesized Pgf^-/- mice would have impaired cognition and altered brain neuroanatomy in addition to compromised cerebrovasculature. Cognitive behavior was assessed in adult Pgf^-/- and Pgf^+/+ mice by four paradigms followed by postmortem high-resolution MRI of neuroanatomy. X-ray microcomputed tomography imaging investigated the three-dimensional cerebrovascular geometry in another cohort. Pgf^-/- mice exhibited poorer spatial memory, less depressive-like behavior, and superior recognition of novel objects. Significantly smaller volumes of 10 structures were detected in the Pgf^-/- compared with Pgf^+/+ brain. Pgf^-/- brain had more total blood vessel segments in the small-diameter range. Lack of PGF altered cognitive functions, brain neuroanatomy, and cerebrovasculature in mice. Pgf^-/- mice may be a preclinical model for the offspring effects of low-PGF preeclampsia gestation.

Systemic Evaluation of Vascular Dysfunction by High-Resolution Sonography in an Nω -Nitro-l-Arginine Methyl Ester Hydrochloride-Induced Mouse Model of Preeclampsia-Like Symptoms

OBJECTIVES

The purpose of this study was to evaluate vascular function, including arterial resistance and endothelial function, by high-resolution sonography in an N_ω -nitro-l-arginine methyl ester hydrochloride (l-NAME)-induced mouse model of preeclampsia-like symptoms.

METHODS

Pregnant mice were subcutaneously injected with a saline solution (control; n = 10) or l-NAME (n = 10) between the 7th and 18th days of gestation. The resistive index and pulsatility index (RI and PI, indicators of arterial resistance) of the uteroplacental, umbilical, femoral, and common carotid arteries and the flow-mediated dilatation (index of endothelial function) of the femoral artery were measured by high-frequency sonography in both groups.

RESULTS

We noted significant increases in the RI and PI of the uteroplacental and umbilical arteries and a decrease in the flow-mediated dilatation of the femoral artery in the l-NAME group compared with the control group. We also found that the RI and PI of the uteroplacental and umbilical arteries were negatively correlated with fetal weight and crown-rump length. The results of the multivariate analysis using a logistic regression model indicated that the flow-mediated dilatation at 120 seconds was an independent diagnostic criterion for the l-NAME-induced preeclampsia-like model. A receiver operating characteristic analysis showed that flow-mediated dilatation at 120 seconds had the greatest area under the curve of 0.934, with an optimal cutoff point of 11.1%, yielding sensitivity of 100% and specificity of 84.6%.

CONCLUSIONS

The PI and RI of the fetomaternal vasculature can identify fetuses in "high-risk" pregnancies, and flow-mediated dilatation is a reliable indicator for predicting preeclampsia. Assessment of vascular function by high-resolution sonography provides a useful platform for preeclampsia-related basic research with high reproducibility.