Placental ischemia and cardiovascular dysfunction in preeclampsia and beyond: making the connections

The role of circular RNA in preeclampsia: From pathophysiological mechanism to clinical application

Preeclampsia (PE) is a common pregnancy-induced hypertension disorder that poses a significant threat to the health of pregnant women and fetuses, and has become a leading cause of maternal, fetal, and neonatal mortality. Currently, the therapy strategy for PE is mainly prevention management and symptomatic treatment, and only delivery can completely terminate PE. Therefore, a deeper understanding of the pathogenesis of PE is needed to make treatment and prevention more effective and targeted. With the deepening of molecular etiology research, circular RNAs (circRNAs) have been found to be widely involved in various processes of PE pathogenesis. As a kind of RNA with a special "head to tail" loop structure, the characteristics of circRNAs enable them to play diverse roles in the pathophysiology of PE, and can also serve as ideal biomarkers for early prediction and monitoring progression of PE. In this review, we summarized the latest research on PE-related circRNAs, trying to elucidate the unique or shared roles of circRNAs in various pathophysiological mechanisms of PE, aiming to provide a whole picture of current research on PE-related circRNAs, and extend a new perspective for the precise screening and targeted therapy of PE.

Impact of Co-Occurrence of Obesity and SARS-CoV-2 Infection during Pregnancy on Placental Pathologies and Adverse Birth Outcomes: A Systematic Review and Narrative Synthesis

Obesity is a risk factor for severe COVID-19 disease during pregnancy. We hypothesized that the co-occurrence of high maternal body mass index (BMI) and gestational SARS-CoV-2 infection are detrimental to fetoplacental development. We conducted a systematic review following PRISMA/SWiM guidelines and 13 studies were eligible. In the case series studies (n = 7), the most frequent placental lesions reported in SARS-CoV-2(+) pregnancies with high maternal BMI were chronic inflammation (71.4%, 5/7 studies), fetal vascular malperfusion (FVM) (71.4%, 5/7 studies), maternal vascular malperfusion (MVM) (85.7%, 6/7 studies) and fibrinoids (100%, 7/7 studies). In the cohort studies (n = 4), three studies reported higher rates of chronic inflammation, MVM, FVM and fibrinoids in SARS-CoV-2(+) pregnancies with high maternal BMI (72%, n = 107/149; mean BMI of 30 kg/m2) compared to SARS-CoV-2(−) pregnancies with high BMI (7.4%, n = 10/135). In the fourth cohort study, common lesions observed in placentae from SARS-CoV-2(+) pregnancies with high BMI (n = 187 pregnancies; mean BMI of 30 kg/m2) were chronic inflammation (99%, 186/187), MVM (40%, n = 74/187) and FVM (26%, n = 48/187). BMI and SARS-CoV-2 infection had no effect on birth anthropometry. SARS-CoV-2 infection during pregnancy associates with increased prevalence of placental pathologies, and high BMI in these pregnancies could further affect fetoplacental trajectories.

Unfolding the role of placental-derived Extracellular Vesicles in Pregnancy: From homeostasis to pathophysiology

The human placenta is a critical structure with multiple roles in pregnancy, including fetal nutrition and support, immunological, mechanical and chemical barrier as well as an endocrine activity. Besides, a growing body of evidence highlight the relevance of this organ on the maternofetal wellbeing not only during gestation, but also from birth onwards. Extracellular vesicles (EVs) are complex macromolecular structures of different size and content, acting as carriers of a diverse set of molecules and information from donor to recipient cells. Since its early development, the production and function of placental-derived EVs are essential to ensure an adequate progress of pregnancy. In turn, the fetus receives and produce their own EVs, highlighting the importance of these components in the maternofetal communication. Moreover, several studies have shown the clinical relevance of EVs in different obstetric pathologies such as preeclampsia, infectious diseases or gestational diabetes, among others, suggesting that they could be used as pathophysiological biomarkers of these diseases. Overall, the aim of this article is to present an updated review of the published basic and translational knowledge focusing on the role of placental-derived EVs in normal and pathological pregnancies. We suggest as well future lines of research to take in this novel and promising field.

Midgestation Leptin Infusion Induces Characteristics of Clinical Preeclampsia in Mice, Which Is Ablated by Endothelial Mineralocorticoid Receptor Deletion

BACKGROUND

Patients with preeclampsia demonstrate increases in placental leptin production in midgestation, and an associated increase in late gestation plasma leptin levels. The consequences of mid-late gestation increases in leptin production in pregnancy is unknown. Our previous work indicates that leptin infusion induces endothelial dysfunction in nonpregnant female mice via leptin-mediated aldosterone production and endothelial mineralocorticoid receptor (ECMR) activation, which is ablated by ECMR deletion. Therefore, we hypothesized that leptin infusion in mid-gestation of pregnancy induces endothelial dysfunction and hypertension, hallmarks of clinical preeclampsia, which are prevented by ECMR deletion.

METHODS

Leptin was infused via miniosmotic pump (0.9 mg/kg per day) into timed-pregnant ECMR-intact (WT) and littermate-mice with ECMR deletion (KO) on gestation day (GD)11-18.

RESULTS

Leptin infusion decreased fetal weight and placental efficiency in WT mice compared with WT+vehicle. Radiotelemetry recording demonstrated that blood pressure increased in leptin-infused WT mice during infusion. Leptin infusion reduced endothelial-dependent relaxation responses to acetylcholine (ACh) in both resistance (second-order mesenteric) and conduit (aorta) vessels in WT pregnant mice. Leptin infusion increased placental ET-1 (endothelin-1) production evidenced by increased PPET-1 (preproendothelin-1) and ECE-1 (endothelin-converting enzyme-1) expressions in WT mice. Adrenal aldosterone synthase (CYP11B2) and angiotensin II type 1 receptor b (AT1Rb) expression increased with leptin infusion in pregnant WT mice. KO pregnant mice demonstrated protection from leptin-induced reductions in pup weight, placental efficiency, increased BP, and endothelial dysfunction.

CONCLUSIONS

Collectively, these data indicate that leptin infusion in midgestation induces endothelial dysfunction, hypertension, and fetal growth restriction in pregnant mice, which is ablated by ECMR deletion.

The Pivotal Role of the Placenta in Normal and Pathological Pregnancies: A Focus on Preeclampsia, Fetal Growth Restriction, and Maternal Chronic Venous Disease

The placenta is a central structure in pregnancy and has pleiotropic functions. This organ grows incredibly rapidly during this period, acting as a mastermind behind different fetal and maternal processes. The relevance of the placenta extends far beyond the pregnancy, being crucial for fetal programming before birth. Having integrative knowledge of this maternofetal structure helps significantly in understanding the development of pregnancy either in a proper or pathophysiological context. Thus, the aim of this review is to summarize the main features of the placenta, with a special focus on its early development, cytoarchitecture, immunology, and functions in non-pathological conditions. In contraposition, the role of the placenta is examined in preeclampsia, a worrisome hypertensive disorder of pregnancy, in order to describe the pathophysiological implications of the placenta in this disease. Likewise, dysfunction of the placenta in fetal growth restriction, a major consequence of preeclampsia, is also discussed, emphasizing the potential clinical strategies derived. Finally, the emerging role of the placenta in maternal chronic venous disease either as a causative agent or as a consequence of the disease is equally treated.

Physiological characterization of an arginine vasopressin rat model of preeclampsia

Rodent models have contributed greatly to our understanding of preeclampsia (PE) progression in humans, however to-date no model has been able to effectively replicate the clinical presentation of the disease. This study aimed to provide a thorough physiological characterization of the arginine vasopressin (AVP)-induced rat model of PE to determine its applicability in studying the pathophysiology of PE. Female Sprague Dawley rats (n = 24) were separated into four groups (n = 6 per group) viz., pregnant AVP, pregnant saline, non-pregnant AVP, and non-pregnant saline. All animals received a continuous dose of either AVP (150 ng/h) or saline via subcutaneous mini osmotic pumps for 18 days. Full physiological characterization of the model included measuring systolic and diastolic blood pressure, and collecting urine and blood samples for biochemical analysis. AVP infusion significantly increased blood pressure and urinary protein levels in the pregnant rats (p < 0.05). Biochemical markers measured, differed significantly in the AVP-treated vs the pregnant saline groups (p < 0.05). Placental and individual pup weight decreased significantly in the pregnant AVP vs pregnant saline group (p < 0.05). The physiological and hematological data confirm the usefulness of this rat model in the study of PE, since AVP-induced vasoconstriction increases peripheral resistance and successfully mimics the pathological changes associated with PE development in humans.Abbreviations: PE: preeclampsia; AVP: arginine vasopressin; ISSHP: International Society for the Study of Hypertension in Pregnancy; ACOG: American College of Obstetricians and Gynecologists; RUPP: reduced uterine perfusion pressure; sFlt-1: soluble fms-like tyrosine kinase; VEGF: vascular endothelial growth factor; PlGF: placental growth factor; AVP: arginine vasopressin; PAVP: pregnant AVP-treated; PS: pregnant saline; GD: gestational day; ALT: alanine transaminase; NAVP: non-pregnant AVP-treated; NS: non-pregnant saline; AST: aspartate aminotransferase; HDL: high-density lipoprotein; RBC: red blood cell; RAAS: renin-angiotensin aldosterone system; HELLP: hemolysis, elevated liver enzymes, low platelet.

Obesity-associated cardiovascular risk in women: hypertension and heart failure

The pathogenesis of obesity-associated cardiovascular diseases begins long prior to the presentation of a cardiovascular event. In both men and women, cardiovascular events, and their associated hospitalizations and mortality, are often clinically predisposed by the presentation of a chronic cardiovascular risk factor. Obesity increases the risk of cardiovascular diseases in both sexes, however, the clinical prevalence of obesity, as well as its contribution to crucial cardiovascular risk factors is dependent on sex. The mechanisms via which obesity leads to cardiovascular risk is also discrepant in women between their premenopausal, pregnancy and postmenopausal phases of life. Emerging data indicate that at all reproductive statuses and ages, the presentation of a cardiovascular event in obese women is strongly associated with hypertension and its subsequent chronic risk factor, heart failure with preserved ejection fraction (HFpEF). In addition, emerging evidence indicates that obesity increases the risk of both hypertension and heart failure in pregnancy. This review will summarize clinical and experimental data on the female-specific prevalence and mechanisms of hypertension and heart failure in women across reproductive stages and highlight the particular risks in pregnancy as well as emerging data in a high-risk ethnicity in women of African ancestry (AA).

The Fourth Trimester: Pregnancy as a Predictor of Cardiovascular Disease

Pregnancy identifies women who may be at a greater risk of cardiovascular disease (CVD), based on the development of adverse pregnancy outcomes (APOs), and may identify women who may benefit from atherosclerotic CVD (ASCVD) risk reduction efforts. APOs are common and although they are separate diagnoses, all these disorders seem to share an underlying pathogenesis. What is not clear is whether the APO itself initiates a pathway that results in CVD or whether the APO uncovers a woman's predisposition to CVD. Regardless, APOs have immediate risks to maternal and foetal health, in addition to longer-term CVD consequences. CVD risk assessment and stratification in women remains complex and, historically, has underestimated risk, especially in young women. Further research is needed into the role of ASCVD risk assessment and the effect of aggressive ASCVD risk modification on CVD outcomes in women with a history of APOs.

Assessment of Correlation Between miR-210 Expression and Pre-Eclampsia Risk: A Meta-Analysis

BACKGROUND

Pre-eclampsia (PE) is a pregnancy disorder characterized by hypertension and proteinuria. The evidence has suggested that microRNAs (miRs) are associated with pre-eclampsia pathogenesis; however, these results are inconsistent. The aim of this study was to assess the association between miR-210 expression and PE risk.

METHODS

Previous studies were selected using PubMed, Scopus, MEDLINE, EMBASE, Science Direct, Google Scholar, Directory of Open Access Journals (DOAJ), and Scientific Information Database (SID). This metaanalysis includes 12 studies associated with miR-210 and pre-eclampsia and necessary information was extracted.

RESULTS

The standardized mean differences [(SMD (0.32) 95% CI (014-0.49), p=0.97] and heterogeneity were determined with the chi-square test (Q=3.63 df =11 p= 0.97), which found no heterogeneity between these studies. Additionally, publication bias was evaluated by Egger's and Begg´s tests. Visual inspection of the funnel plot graphically, and statistically with Egger's weighted regression [(p= 0.35) (95% CI -0.90 - 2.29)] and Begg's rank correlation (p= 0.21), found no important publication bias between studies within the meta-analysis.

CONCLUSION

Our findings suggest that miR-210 contributes to the pathogenesis of PE; therefore, miR-210 could serve as a novel biomarker to predict PE pathophysiology. Further studies are required in this field to characterize the mechanism involved in this process.

New conception for the development of hypertension in preeclampsia

Placental vascular dysfunction was suggested to be critical for placental ischemia-initiated hypertension in preeclampsia, although the contributions of endothelium involved are unclear. The present study found, unlike non-placental vessels, acetylcholine showed no vasodilatation effect on placental vessels, indicating that endothelial-derived nitric oxide (NO) was extremely weak in placental vessels. Placental vascular responses to exogenous NO from sodium nitroprusside (SNP) were significantly different from non-placental vessels. These results were further confirmed in sheep, and rat vessels. In preeclamptic placental vessels, acetylcholine also showed no vasodilatation effects, while vascular responses to SNP were suppressed, associated with impaired cGMP/sGC pathway in vascular smooth muscle cells (VSMCs). The current theory on placental ischemia-initiated hypertension in preeclampsia focused on changes in placental vascular functions, including endothelial dysfunction. This study found the placental endothelium contributed very poorly to vasodilatation, and altered vascular functions in preeclampsia mainly occurred in VSMCs instead of endothelial cells. The findings contribute importantly to understanding the special feature of placental vascular functions and its pathophysiological changes in the development of hypertension in preeclampsia.

Sex-specific cardiovascular susceptibility to ischaemic myocardial injury following exposure to prenatal hypoxia

Cardiovascular diseases (CVDs) are the leading cause of mortality and hypertension contributes substantially to the incidence of stroke, coronary artery disease, heart failure, atrial fibrillation and peripheral vascular disease. The origin of hypertension is clearly multifactorial, and a complex and multifaceted approach is necessary to decrease its incidence. The most recognizable factors involved in reducing the incidence of hypertension are prevention, early diagnosis and treatment; however, the importance of the foetal environment and early postnatal development has recently been considered. In clinical practice, these factors are still frequently overlooked, probably because of a lack of knowledge about the underlying mechanisms and effective treatment or prevention. Pathophysiological mechanisms underlying the prenatal programming of CVDs were investigated in the study by Shah et al. published recently in Clinical Science (2017) 131(17), 2303–2317. The study explored cardiac susceptibility of adult male and female rat offspring to ischaemic myocardial injury due to prenatal exposure to hypoxia. The results demonstrated significant changes in global cardiac function and left ventricular dilatation following myocardial infarction in rat offspring prenatally exposed to hypoxia. The effects were gender specific and occurred only in males, whereas females were protected. These findings are important from several perspectives. First, they point to the fact that an inadequate foetal environment can increase susceptibility to death from myocardial infarction. Second, during their reproductive life, females are better protected from cardiovascular insult than males, but it is not known if they lose this advantage after menopause, and can be equally at risk as males.

Mechanisms of fetal epigenetics that determine telomere dynamics and health span in adulthood

Advances in epigenetics now enable us to better understand environmental influences on the genetic background of human diseases. This refers especially to fetal development where an adverse intrauterine environment impacts oxygen and nutrient supply to the fetus. Recently, differences in telomere length and telomere loss dynamics among individuals born with intrauterine growth restriction compared to normal controls have been described. In this paper we propose possible molecular mechanisms that (pre)program telomere epigenetics during pregnancy. This programming sets differences in telomere lengths and dynamics of telomere shortening in adulthood and therefore dictates the dynamics of aging and morbidity in later life.

Maternal and Cord Blood Plasma sEng and TGF-β1 in Patients with Hypertensive Disorders of Pregnancy: A Pilot Study in a South Indian Population

INTRODUCTION

Hypertensive Disorders of Pregnancy (HDP) are one of the most widespread complications of pregnancy that affects both mother and foetus. It has been observed that in Preeclampsia, the release of soluble angiogenic factors from the ischemic placenta into maternal plasma plays a crucial role in the pathogenesis.

AIM

To assess the plasma Soluble Endoglin (sEng) and Transforming Growth Factor (TGF-β1) levels in various types of HDP and to correlate the levels of these markers with the pregnancy outcome.

MATERIALS AND METHODS

A total of 128 pregnant women were recruited and the study was carried out for a period of three years. Cord blood and maternal blood plasma levels of sEng and TGF-β1 were analysed by ELISA kits in Control Pregnant Women (CPW), Gestational Hypertension (GH), Early Onset Preeclampsia (EOPE), Late Onset Preeclampsia (LOPE), and Eclampsia (E) during third trimester. The Gestational Age (GA) at the time of delivery and Birth Weight (BW) of the baby also were also evaluated.

RESULTS

The circulating levels of maternal and cord blood sEng were significantly higher in EOPE and E compared to CPW and GH. However, the maternal and cord blood levels of TGF-β1 were significantly lower in LOPE and E when compared to CPW and GH. The GA and BW of the baby were found to be significantly lower in EOPE and E compared to CPW, GH and LOPE. Also, a negative correlation was observed between sEng levels with pregnancy outcome; GA and BW. And also, a positive correlation was found between TGF-β1 and pregnancy outcome.

CONCLUSION

A generalised angiogenic imbalance and poor birth outcomes were observed in HDP. There is a spectrum of biochemical derangements related to angiogenesis in GH, EOPE, LOPE and E.

From apelin to exercise: emerging therapies for management of hypertension in pregnancy

Studies over the last couple of decades have provided exciting new insights into mechanisms underlying the pathogenesis of preeclampsia. In addition, several novel and innovative molecules and ideas for management of the syndrome have also come forth. While our basic understanding of the initiating events of preeclampsia continues to be placental ischemia/hypoxia stimulating the release of a variety of factors from the placenta that act on the cardiovascular and renal systems, the number of candidate pathways for intervention continues to increase. Recent studies have identified apelin and its receptor, APJ, as an important contributor to the regulation of cardiovascular and fluid balance that is found to be disrupted in preeclampsia. Likewise, continued studies have revealed a critical role for the complement arm of the innate immune system in placental ischemia induced hypertension and in preeclampsia. Finally, the recent increase in animal models for studying hypertensive disorders of pregnancy has provided opportunities to evaluate the potential role for physical activity and exercise in a more mechanistic fashion. While the exact quantitative importance of the various endothelial and humoral factors that mediate vasoconstriction and elevation of arterial pressure during preeclampsia remains unclear, significant progress has been made. Thus, the goal of this review is to discuss recent efforts towards identifying therapies for hypertension during pregnancy that derive from work exploring the apelinergic system, the complement system as well as the role that exercise and physical activity may play to that end.

Spectrum of Factors Triggering Endothelial Dysfunction in PIH

INTRODUCTION

Pre-eclampsia (PE) is a major cause of maternal and fetal/neonatal mortality and morbidity. The aetiology and pathogenesis of PE is yet to be completely understood. Evidence shows that, Endothelial Dysfunction (ED) plays a pivotal role in the genesis of this multi-system disorder that develops in PE and eclampsia.

AIM

To determine the circulating levels of factors Malondialdehyde (MDA), Ferric Reducing Ability of Plasma-α (FRAP), Tumour Necrosis Factor (TNF-α), sFlt-1, VEGF, PlGF, Nitric Oxide (NO) that influence the ED.

MATERIALS AND METHODS

Study groups consisted of Normotensive pregnant women (N), preeclamptic women (PE) and eclamptic women (E) with 100 subjects in each group in the 3^rd trimester of pregnancy. They were investigated for MDA, FRAP, TNF-α, sFlt-1, VEGF, PlGF, NO. Statistical analysis was done using Analysis of Variance (ANOVA).

RESULTS

When compared to controls MDA, TNF-α, sFlt-1 levels were found to be significantly high and FRAP, VEGF, PIGF and NO levels were significantly low in PE and E group. E showed a significantly high level of MDA, TNF-α, sFlt-1 and low levels of FRAP, VEGF, PIGF, NO when compared to PE group.

CONCLUSION

Our study substantiated the fact, that oxidative stress, imbalance between anti-angiogenic factors and pro- angiogenic factors exists in Pregnancy Induced Hypertension (PIH) condition. This imbalance is directly related to the ED, the hallmark of PE. So oxidative stress, VEGF, PlGF and sFlt-1 can be used as markers to analyze the onset and progression of the disease.

Is preeclampsia an independent predictor of diastolic dysfunction? A retrospective cohort study

OBJECTIVE

To determine if preeclampsia is an independent predictor of diastolic dysfunction and what factors among patients with preeclampsia are associated with diastolic dysfunction.

METHODS

This is a retrospective cohort study of patients who delivered between 2008 and 2013 at a single institution who had a maternal echocardiogram during their pregnancy or within 5months of delivery. Patients with structural heart disease, ejection fraction less than 45%, pulmonary embolus, or age over 45years were excluded. Medical records were reviewed for medical and obstetric complications and echocardiogram findings. Demographic characteristics and rate of diastolic dysfunction were compared between patients with preeclampsia and without preeclampsia. Multivariate logistic regression was performed controlling for age, ethnicity, gestational age at delivery, diabetes, preeclampsia, intrauterine growth restriction (IUGR), antihypertensive use and magnesium sulfate administration.

RESULTS

Sixty-six patients were identified, of which 39 (59%) had preeclampsia. Past history of preeclampsia, IUGR in the current pregnancy, antihypertensive use and magnesium sulfate use were higher in the preeclampsia group. Fifteen patients (39%) in the preeclampsia group were African-American compared to 2 (3%) in the control group (p<0.01). Seventeen (44%) of the patients with preeclampsia were found to have diastolic dysfunction compared to 3 (11%) controls (OR=6.18, 95% CI 1.59,24.02; p=0.006). Logistic regression analysis did not reveal other independent predictors of diastolic dysfunction. In the patients with preeclampsia, history of preeclampsia with severe features and IUGR were not associated with diastolic dysfunction.

CONCLUSIONS

Our study supports previous findings that preeclampsia is associated with diastolic dysfunction.

Role of the sympathetic autonomic nervous system in hypoxic remodeling of the fetal cerebral vasculature

Fetal hypoxia triggers compensatory angiogenesis and remodeling through mechanisms not fully elucidated. In response to hypoxia, hypoxia-inducible factor drives expression of cytokines that exert multiple effects on cerebral structures. Among these, the artery wall is composed of a heterogeneous cell mix and exhibits distinct patterns of cellular differentiation and reactivity. Governing these patterns are the vascular endothelium, smooth muscle (SM), adventitia, sympathetic perivascular nerves (SPN), and the parenchyma. Although an extensive literature details effects of nonneuronal factors on cerebral arteries, the trophic role of perivascular nerves remains unclear. Hypoxia increases sympathetic innervation with subsequent release of norepinephrine (NE), neuropeptide-Y (NPY), and adenosine triphosphate, which exert motor and trophic effects on cerebral arteries and influence dynamic transitions among SM phenotypes. Our data also suggest that the cerebrovasculature reacts very differently to hypoxia in fetuses and adults, and we hypothesize that these differences arise from age-related differences in arterial SM phenotype reactivity and proximity to trophic factors, particularly of neural origin. We provide an integration of recent literature focused on mechanisms by which SPN mediate hypoxic remodeling. Our recent findings suggest that trophic effects of SPN on cerebral arteries accelerate functional maturation through shifts in SM phenotype in an age-dependent manner.

FOXO1 expression in villous trophoblast of preeclampsia and fetal growth restriction placentas

Oxidative stress and increased apoptosis are implicated in the pathogenesis of many disorders of pregnancy, including preeclampsia (PE) and fetal growth restriction (FGR). Since the transcription factor FOXO1 (forkhead box protein O1) is implicated in the regulation of a variety of cellular processes, including resistance to oxidative stress, apoptosis and morphogenesis of the placenta, we examined whether FOXO1 expression is abnormal in placentas from patients with PE or FGR. Paracentral sections from grossly unremarkable areas of 9 or 10 placentas each from early third trimester patients (31.7±5.0 weeks) with mild PE, severe PE, FGR and a gestational age-matched comparison group (GA controls) were double immunostained for FOXO1 and E-cadherin, the latter distinguishing villous cytotrophoblast cells (CTB) from syncytiotrophoblast (STB). The numbers of FOXO1-positive and FOXO1 negative STB and CTB nuclei were determined on ten 20x objective fields of each placenta section by three observers who were blinded to the clinical outcome. The results were evaluated by a generalized linear mixed model. In mild PE, FOXO1-positive STB nuclei were significantly decreased in number and FOXO1-negative STB nuclei were increased as compared to GA controls. However, the number of FOXO1-positive and FOXO1-negative CTB nuclei were not significantly changes as compared to GA controls. In severe PE and FGR, the numbers of FOXO-positive and FOXO1-negative STB and CTB were not statistically different from GA controls. Since FOXO1 is critical for placental cellular morphogenesis, abnormal FOXO1 expression may contribute in part to the abnormal trophoblast differentiation in mild PE. The differences in FOXO1 expression in mild and severe PE are consistent with other studies suggesting that the two forms of PE are different disease processes.

Proteomic approaches to evaluate protein S-nitrosylation in disease

Many of nitric oxide (NO) actions are mediated through the coupling of a nitroso moiety to a reactive cysteine leading to the formation of a S-nitrosothiol (SNO), a process known as S-nitrosylation or S-nitrosation. In many cases this reversible post-translational modification is accompanied by altered protein function and aberrant S-nitrosylation of proteins, caused by altered production of NO and/or impaired SNO homeostasis, has been repeatedly reported in a variety of pathophysiological settings. A growing number of studies are directed to the identification and characterization of those proteins that undergo S-nitrosylation and the analysis of S-nitrosoproteomes under pathological conditions is beginning to be reported. The study of these S-nitrosoproteomes has been fueled by advances in proteomic technologies that are providing researchers with improved tools for exploring this post-translational modification. Here we review novel refinements and improvements to these methods, and some recent studies of the S-nitrosoproteome in disease.

Growth factors in preeclampsia: a vascular disease model. A failed vasodilation and angiogenic challenge from pregnancy onwards?

Preeclampsia is the major cause of maternofetal and neonatal morbi-mortality including intrauterine growth retardation, miscarriages and stillbirths. Inadequate vascular dilation and angiogenesis represent the crucial underlying defect of gravidic hypertension, denoting a failed response to the vasodilatory and pro-angiogenic challenge imposed by pregnancy, especially if multifetal. A similar pathogenesis appears involved in gestational diabetes. In this review we aimed to provide a hint on understanding the deeply involved angiogenic disorders which eventually culminate in utero-placental failure. The key players in these complex processes may be found in an intricate network of growth factors (GFs) and GF inhibitors, controlled by several vascular risk factors modulated by environment and genes, which eventually impact on early and late cardiovascular outcomes of mother and fetus.

Distribution of sugar residues in human placentas from pregnancies complicated by hypertensive disorders

The aim of the study was to investigate the content and distribution of sugar residues in placentas from pregnancies complicated by hypertensive disorders. Placentas from women with uncomplicated pregnancies (group 1), pregnancies complicated by gestational hypertension (group 2), pregnancies complicated by pre-eclampsia (group 3), pregnancies complicated by pre-eclampsia with HELLP syndrome (hemolysis, elevated liver enzymes and low platelets) (group 4) were collected. Lectins: ConA, WGA, PNA, SBA, DBA, UEA I, GNA, DSA, MAA, SNA, in combination with chemical and enzymatic treatments, were used. Data showed a decrease and/or lack of α-d-mannose, α-d-glucose and d-galactose-(β1-4)-N-acetyl-d-glucosamine in placentas from pre-eclampsia and pre-eclampsia with HELLP syndrome compared with control and hypertension cases. N-acetyl-d-galactosamine appeared and/or increased in placentas from hypertensive disorders. A different distribution of various types of sialic acid was observed in placentas from hypertensive disorders compared with the controls. In particular, placentas from pre-eclampsia, with and without HELLP syndrome, lacked the acetylated sialic acid side-chain. These findings demonstrate various alterations of the carbohydrate metabolism in the placentas from pregnancies complicated by different types of hypertensive disorders. This indicates correlation with the placental morpho-functional changes characteristic of these complications and with the degree of clinical severity.

Decreased Cyr61 under hypoxia induces extravillous trophoblasts apoptosis and preeclampsia

During placental development, oxygen environment is not only critical for trophoblasts migration and invasion, but also fundamental for appropriate placental perfusion. Cysteine-rich 61 (Cyr61, CCN1) was expressed in the extravillous trophoblasts (EVTs) and decreased in preeclampsia. Its regulatory properties in human first-trimester extravillous trophoblast cell line (TEV-1 cells) upon a low oxygen tension were investigated. The present study examined functional changes involved in adaptation to hypoxia of the TEV-1 cells, using cobalt chloride (CoCl(2)) as hypoxic mimic. It was found that hypoxia inhibited growth of TEV-1 cells and induced the increase of cell apoptosis (P<0.05). The Cyr61 expression in human EVTs was transcriptionally induced by CoCl(2). Inappropriate EVTs apoptosis has been implicated in the failure of trophoblasts to fully invade and modify the uterine environment and Cyr61 down-regulation, potentially leading to preeclampsia.

Changes in maternal serum thioredoxin (TRX) levels after delivery in preeclamptic and normotensive pregnant women

OBJECTIVE

To investigate changes of maternal plasma thioredoxin (TRX) levels after delivery in preeclamptic and normotensive pregnant women.

METHODS

Ten normotensive women (group A) were compared to 17 women with severe preeclampsia (group B). TRX levels were assessed in maternal plasma, immediately after delivery and 12-16 weeks postpartum.

RESULTS

There were no differences in plasma TRX levels between the two groups immediately antepartum (p = 0.095). A significant reduction in plasma TRX levels was found immediately following delivery only in normotensive group (117.76 ± 37.19 ng/mL vs. 43.45 ± 21.11 ng/mL, p = 0.002), but not in women with preeclampsia (80.42 ± 59.95 ng/mL vs. 53.82 ± 44.34 ng/mL, p = 0.12). Plasma TRX levels remained unchanged in women with preeclampsia (80.42 ± 59.95 ng/mL vs. 55.37 ± 52.23 ng/mL, p = 0.2) at 12-14 weeks postpartum.

Expression profile of microRNAs and mRNAs in human placentas from pregnancies complicated by preeclampsia and preterm labor

MicroRNAs (miRNAs) have emerged as key regulators of gene expression stability implicated in cell proliferation, apoptosis, and development, whereas their altered expression has been associated with various pathological disorders. The objective of this study was to assess the expression profile of miRNAs and their predicted target genes in placentas from patients with preeclampsia (PC) and preterm (PT) labor as compared to normal term (NT) pregnancies. Using microarray profiling of 820 miRNAs and 18,630 mRNA transcripts, the analysis indicated that 283 of these miRNAs and 9119 mRNAs were expressed in all placentas, of which the relative expression of 20 miRNAs (P < .05 and ≥ 1.5-fold) and 120 mRNAs (P < .05, and 2-fold cutoff) was differentially expressed in PT and PC as compared to NT. The expression of miR-15b, miR-181a, miR-200C, miR-210, miR-296-3p, miR-377, miR-483-5p, and miR-493 and a few of their predicted target genes: matrix metalloproteinases (MMP-1, MMP-9), a disintegrin and metalloproteinase domains (ADAM-17, ADAM-30), tissue inhibitor of metalloproteinase 3 (TIMP-3); suppressor of cytokine signaling 1 (SOCS1); Stanniocalcin (STC2); corticotropin-releasing hormone (CRH), CRH-binding protein (CRHBP); and endothelin-2 (EDN2) were validated in these cohorts using real-time polymerase chain reaction (PCR), some displaying an inverse correlation with the expression of their predicted target genes. Functional analysis indicated that the products of these genes regulate cellular activities considered critical in normal placental functions and those affected by PC and PT labor. In conclusion, the results provide further evidence that placentas affected by PC and PT labor display an altered expression of a number of miRNAs with potential regulatory functions on the expression of specific target genes whose altered expression and function have been associated with these pregnancy complications.

Does transthyretin function as one of contributors for preeclampsia?

Preeclampsia (PE) is a multi-system disorder of pregnancy, which is characterized by new onset hypertension and proteinuria, resulting in multi-organ damages within a potential procedure. However as a worldwide leading cause of maternal and fetal mortality and morbidity, the precise origin of PE has not been clarified yet, which also makes obstacles to the management of the disease. Transthyretin (TTR) is a special protein involved in amyloid diseases, has important effects on amyloid fibrils formation. We assumed that TTR might cause a disorder of maternal vascular function and contributed to the pathology of the disease by deposition of TTR amyloid fibrils in the vascular system, which are produced by variant TTR proteins, resulting in organ ischemia. If this hypothesis proves to be correct, this variant may be of diagnostic importance as novel biomarkers for the disease, in addition, it might also benefit to the management of PE.

Regulation of the matricellular proteins CYR61 (CCN1) and NOV (CCN3) by hypoxia-inducible factor-1{alpha} and transforming-growth factor-{beta}3 in the human trophoblast

It is known that a hypoxic environment is critical for trophoblast migration and invasion and is fundamental for appropriate placental perfusion. Because cysteine-rich 61 (CYR61, CCN1) and nephroblastoma overexpressed (NOV, CCN3) are expressed in the extravillous trophoblast and expression levels are deregulated in preeclampsia, we investigated their regulation properties in first-trimester placental explants and in JEG3 choriocarcinoma cells upon a physiological low oxygen tension of 1-3%. In placental explants, both proteins were expressed in the extravillous trophoblast cells and were increased upon hypoxia. JEG3 cells revealed a significant up-regulation of CYR61 and NOV intracellular as well as secreted protein upon hypoxic treatment accompanied by the stabilization of the hypoxia-inducible factor-1alpha (HIF-1alpha). Treatment with dimethyloxalylglycine to mimic hypoxia and silencing of HIF-1alpha using small interfering RNA revealed that only the increase in intracellular protein expression seems to be dependent on HIF-1alpha but obviously not the secretion process. Moreover, recombinant TGF-beta3 was able to further enhance the amount of intracellular CCN proteins as well as secreted CYR61 levels under hypoxia. These results indicate that low oxygen levels trigger elevation of intracellular as well as secreted CYR61 and NOV protein probably in two independent pathways. Addition of recombinant CYR61 and NOV proteins increases migration as well as invasion properties of JEG3 trophoblast cells, which strengthen their role in supporting trophoblast migration invasion properties. In summary, CYR61 and NOV are regulated by HIF-1alpha and TGF-beta3 in the trophoblast cell line JEG3, and their enhanced secretion could be implicated in appropriate placental invasion.

Clinical differences between early-onset HELLP syndrome and early-onset preeclampsia during pregnancy and at least 6 months postpartum

OBJECTIVE

We sought to evaluate whether clinical and laboratory variables differ between former patients who had HELLP syndrome and former patients who had preeclampsia (PE) without HELLP.

STUDY DESIGN

We compared early-onset HELLP (n = 75) with early-onset PE (n = 40) with respect to clinical features during the hypertensive complication and to metabolic, hemodynamic, and hemostatic variables determined at least 6 months postpartum.

RESULTS

HELLP differed from PE by a borderline higher frequency of eclampsia (13% vs 3%) during the complication, and by a lower prevalence of hypertension (19% vs 33%), proteinuria (2% vs 23%), thrombophilia (6% vs 27%), obesity (9% vs 33%), hypertriglyceridemia (1% vs 15%), hyperglycemia (0% vs 11%), and elevated levels of fasting homocysteine (6% vs 21%) at least 6 months postpartum.

CONCLUSION

Women with HELLP had fewer signs of abnormalities consistent with the metabolic syndrome and a 4-fold lower prevalence of thrombophilia as compared with PE women without HELLP.

Recombinant vascular endothelial growth factor 121 infusion lowers blood pressure and improves renal function in rats with placentalischemia-induced hypertension

Antagonism of vascular endothelial growth factor (VEGF) signaling by soluble fms-like tyrosine kinase 1 occurs during preeclampsia and is proposed to play an important role in the pathogenesis of preeclampsia. We reported recently that hypertension associated with chronic reductions in uteroplacental perfusion pressure (RUPP) is associated with increased soluble fms-like tyrosine kinase 1 and decreased free VEGF. Whether restoration of circulating VEGF can restore renal function and chronically decrease arterial pressure associated with placental ischemia remains unknown. We hypothesized that chronic infusion of VEGF(121) would attenuate hypertension, increase glomerular filtration rate, and reverse the endothelial dysfunction associated with chronic RUPP. VEGF(121) (at either 90 or 180 microg/kg per day) was administered for 5 days via osmotic minipump placed IP. Mean arterial pressure, renal function, and tissues were obtained on day 19 of pregnancy from RUPP+VEGF, RUPP, and normal pregnant dams. Mean arterial pressure was increased in the RUPP (131+/-3 mm Hg) compared with the normal pregnant (102+/-1 mm Hg) rats, and infusion of VEGF(121) resolved the hypertension (105+/-5 mm Hg). Glomerular filtration rate was decreased in the RUPP dams (1.5+/-0.3 mL/min) and restored to normal pregnant levels (3.1+/-0.5 mL/min) by VEGF(121) treatment (3.1+/-0.4 mL/min). Effective renal plasma flow, decreased by RUPP, was also increased by VEGF(121) infusion. Relaxation to acetylcholine was enhanced by the VEGF treatment (P<0.05). These data demonstrate that chronic infusion of VEGF(121) during late gestation restores glomerular filtration rate and endothelial function and reduces high blood pressure associated with placental ischemia. The present results suggest that VEGF(121) may be a candidate molecule for management of preeclampsia and its related complications.

Placental ischemia and breast cancer risk after preeclampsia: tying the knot

Although hypertensive disorders of pregnancy, such as preeclampsia, continue to be a significant source of maternal and fetal morbidity and mortality, there is emerging evidence that effects of the preeclamptic syndrome persist into later life. In contrast to recent studies that have reported that formerly preeclamptic women are at increased risk for cardiovascular disease, it appears that preeclampsia may be associated with a decreased risk of breast cancer. Recent investigations have provided exciting new insights into potential mechanisms underlying the pathogenesis of preeclampsia and some of these findings may bear relevance to the anticancer effects reported in the epidemiological literature. Placental ischemia is regarded to be a primary factor in preeclampsia and the ischemic placenta produces a variety of factors that generate profound effects on endothelial cell function and the cardiovascular system during pregnancy. Moreover, several of these factors are reportedly elevated many years after preeclamptic pregnancies. This group of molecules includes factors such as soluble fms-like tyrosine kinase-1 (sFlt-1), soluble endoglin/CD105 (sEng) and various cytokines. Many of these factors have been strongly associated with cancer incidence and, hence, could contribute to the modification of cancer risk observed in these women. Therefore, identifying potential connections between placental dysfunction and future cancer risk is an important endeavor towards realizing novel therapeutic regimens for cancer patients.

Reducing stillbirths: prevention and management of medical disorders and infections during pregnancy

BACKGROUND

An estimated two-thirds of the world's 3.2 million stillbirths occur antenatally, prior to labour, and are often overlooked in policy and programs. Poorly recognised, untreated or inadequately treated maternal infections such as syphilis and malaria, and maternal conditions including hypertensive disorders, are known risk factors for stillbirth.

METHODS

We undertook a systematic review of the evidence for 16 antenatal interventions with the potential to prevent stillbirths. We searched a range of sources including PubMed and the Cochrane Library. For interventions with prior Cochrane reviews, we conducted additional meta-analyses including eligible newer randomised controlled trials following the Cochrane protocol. We focused on interventions deliverable at the community level in low-/middle-income countries, where the burden of stillbirths is greatest.

RESULTS

Few of the studies we included reported stillbirth as an outcome; most that did were underpowered to assess this outcome. While Cochrane reviews or meta-analyses were available for many interventions, few focused on stillbirth or perinatal mortality as outcomes, and evidence was frequently conflicting. Several interventions showed clear evidence of impact on stillbirths, including heparin therapy for certain maternal indications; syphilis screening and treatment; and insecticide-treated bed nets for prevention of malaria. Other interventions, such as management of obstetric intrahepatic cholestasis, maternal anti-helminthic treatment, and intermittent preventive treatment of malaria, showed promising impact on stillbirth rates but require confirmatory studies. Several interventions reduced known risk factors for stillbirth (e.g., anti-hypertensive drugs for chronic hypertension), yet failed to show statistically significant impact on stillbirth or perinatal mortality rates. Periodontal disease emerged as a clear risk factor for stillbirth but no interventions have reduced stillbirth rates.

CONCLUSION

Evidence for some newly recognised risk factors for stillbirth, including periodontal disease, suggests the need for large, appropriately designed randomised trials to test whether intervention can minimise these risks and prevent stillbirths. Existing evidence strongly supports infection control measures, including syphilis screening and treatment and malaria prophylaxis in endemic areas, for preventing antepartum stillbirths. These interventions should be incorporated into antenatal care programs based on attributable risks and burden of disease.