A critical role of interleukin-10 in modulating hypoxia-induced preeclampsia-like disease in mice

Downregulated PSME3 Contributes to Severe Preeclampsia by Promoting Trophoblast Cell Apoptosis

BACKGROUND

Severe preeclampsia (sPE) is a serious condition posing risks to both maternal and fetal health. Based on mass spectrometry analysis, we identified a key protein, PSME3 (proteasome activator subunit 3), an 11S proteasome activator, whose protein level was significantly downregulated in sPE placentas and whose function in sPE remains unknown.

METHODS

PSME3 protein levels in human placental tissue were detected using Western blot, and PSME3 concentration in serum was detected by ELISA assay. The human preeclampsia-like phenotypes of Psme3-/- pregnant mice were examined. Trophoblast cell apoptosis was detected by flow cytometry. Pregnant mice were treated with 9.5% O2 to construct a preeclampsia mouse model for detecting placental Psme3 expression. The regulation of PSME3 expression by hypoxia was detected in trophoblast cell lines treated with 21% O2 or 1% O2.

RESULTS

PSME3 protein levels were significantly downregulated in sPE placentas and serum. Pregnant mice with Psme3-/- embryos and placentas spontaneously presented human preeclampsia-like symptoms, including hypertension and proteinuria, increased serum soluble fms-like tyrosine kinase 1 concentration, fetal growth restriction, and increased cellular apoptosis. Mechanically, PSME3 knockdown promoted the apoptosis of trophoblast cells by repressing the degradation of UBE2V2 (ubiquitin conjugating enzyme E2 V2). Moreover, the placentas of hypoxia-induced preeclampsia mice presented significantly reduced Psme3 protein levels and elevated Ube2v2 protein levels. Hypoxia-inducible factor-1α functioned as a transcriptional repressor of PSME3.

CONCLUSIONS

In sPE placentas, hypoxia of the placenta may lead to the transcriptional inhibition of PSME3. PSME3 deficiency promotes the accumulation of UBE2V2, thereby inducing trophoblast cell apoptosis. Our study provides a new perspective for elucidating the pathogenesis of sPE.

Analysis of Inflammatory Markers in Response to Induction of Reprometabolic Syndrome by a Eucaloric High Fat Diet in Normal Weight Women

Obesity is associated with chronic low-level inflammation and is known to contribute to metabolic dysfunction and hypogonadotropic hypogonadism, which we have previously termed the 'Reprometabolic Syndrome.' To investigate potential factors involved in obesity-related reproductive endocrine dysfunction, we conducted a secondary analysis of inflammatory markers in a sample of normal weight women exposed to a one-month eucaloric high-fat diet (HFD), which, as reported earlier, induced the relative hypogonadotropic hypogonadism characteristic of Reprometabolic Syndrome. Eighteen healthy women with a BMI between 18.0-24.9 kg/m2 and regular menstrual cycles participated in the study. Frequent blood sampling was performed during the early follicular phase before and after the one-month eucaloric HFD intervention (48% of calories from fat). Serum samples pooled from each participant were analyzed using immunoassay to measure levels of 30 cytokines, interleukins, and chemokines. Differences between pre- and post-HFD intervention measures were examined by one-sample t-tests. Exposure to the eucaloric HFD did not result in changes in body weight. HFD-induction of Reprometabolic Syndrome in normal weight women was associated with a significant elevation only in the anti- inflammatory cytokine IL-10 (p = 0.04). Eotaxin, IL-6 and MIP-1β also increased in response to the HFD, but not statistically significantly (p = 0.07). Results suggest that the increase in multiple inflammatory markers, typically associated with obesity, are not primary mediators of the relative hypogonadotropic hypogonadism of Reprometabolic Syndrome. Clinical Trials Registration Number: NCT02653092; Date of Registration: January 6, 2016.

Alleviation of preeclampsia-like symptoms through PlGF and eNOS regulation by hypoxia- and NF-κB-responsive miR-214-3p deletion

Preeclampsia is caused by placental hypoxia and systemic inflammation and is associated with reduced placental growth factor (PlGF) and endothelial nitric oxide synthase (eNOS) levels. The molecular signaling axes involved in this process may play a role in the pathogenesis of preeclampsia. Here, we found that hypoxic exposure increased hypoxia-inducible factor-1α (HIF-1α)/Twist1-mediated miR-214-3p biogenesis in trophoblasts, suppressing PlGF production and trophoblast invasion. TNF-α stimulation increased NF-κB-dependent miR-214-3p expression in endothelial cells, impairing eNOS expression and causing endothelial dysfunction. Synthetic miR-214-3p administration to pregnant mice decreased PlGF and eNOS expression, resulting in preeclampsia-like symptoms, including hypertension, proteinuria, and fetal growth restriction. Conversely, miR-214-3p deletion maintained the PlGF and eNOS levels in hypoxic pregnant mice, alleviating preeclampsia-like symptoms and signs. These findings provide new insights into the role of HIF-1/Twist1- and NF-κB-responsive miR-214-3p-dependent PlGF and eNOS downregulation in the pathogenesis of preeclampsia and establish miR-214-3p as a therapeutic or preventive target for preeclampsia and its complications.

The Role of Regulatory T Cells and Their Therapeutic Potential in Hypertensive Disease of Pregnancy: A Literature Review

Hypertensive disorders of pregnancy (HDP), including preeclampsia (PE) and gestational hypertension (GH), are major causes of maternal and foetal morbidity and mortality. This review elucidates the role of regulatory T cells (Tregs) in the immunological aspects of HDP and explores their therapeutic potential. Tregs, which play a critical role in maintaining immune homeostasis, are crucial in pregnancy to prevent immune-mediated rejection of the foetus. The review highlights that Tregs contribute to immunological adaptation in normal pregnancy, ensuring foetal acceptance. In contrast, HDP is associated with Treg dysfunction, which is marked by decreased numbers and impaired regulatory capacity, leading to inadequate immune tolerance and abnormal placental development. This dysfunction is particularly evident in PE, in which Tregs fail to adequately modulate the maternal immune response against foetal antigens, contributing to the pathophysiology of the disorder. Therapeutic interventions aiming to modulate Treg activity represent a promising avenue for HDP management. Studies in animal models and limited clinical trials suggest that enhancing Treg functionality could mitigate HDP symptoms and improve pregnancy outcomes. However, given the multifactorial nature of HDP and the intricate regulatory mechanisms of Tregs, the review explores the complexities of translating in vitro and animal model findings into effective clinical therapies. In conclusion, while the precise role of Tregs in HDP is still being unravelled, their central role in immune regulation during pregnancy is indisputable. Further research is needed to fully understand the mechanisms by which Tregs contribute to HDP and to develop targeted therapies that can safely and effectively harness their regulatory potential for treating hypertensive diseases of pregnancy.

Histopathological Clues of Enhanced Inflammation in the Placental Tissue of Women with Chronic Venous Disease in Lower Limbs during Pregnancy

It is estimated that approximately one in three women develop chronic venous disease (CVD) during pregnancy, a broad spectrum of morphofunctional disorders affecting the venous system in different regions of the body, including the lower limbs. A growing body of evidence supports the diverse maternofetal consequences derived from this condition, with the placenta being an organ particularly affected. Among other consequences, having CVD during pregnancy has been associated with systemic inflammation and altered cytokines and chemokine profiles in the maternal and fetal serum related to this condition. In the present work, we aimed to analyze if these inflammatory changes also occurred in the placental tissue of women with CVD, exploring by immunohistochemistry and real-time PCR (RT-qPCR) gene and protein expression of critical inflammatory markers like allograft inflammatory factor 1 (AIF-1), interleukin 10 (IL-10), IL-12A, and IL-18. Our results demonstrate an enhanced tissue expression of AIF-1, IL-12A, and IL-18, accompanied by a decrease in IL-10 in the placentas of women who had undergone CVD during pregnancy. Overall, our results suggest a possible pathophysiological role of inflammation in the placental tissue of women with CVD during pregnancy, although the precise consequences of this feature remain to be deeply analyzed.

GBS hyaluronidase mediates immune suppression in a TLR2/4- and IL-10-dependent manner during pregnancy-associated infection

IMPORTANCE

Bacteria such as GBS can cause infections during pregnancy leading to preterm births, stillbirths, and neonatal infections. The interaction between host and bacterial factors during infections in the placenta is not fully understood. GBS secretes a hyaluronidase enzyme that is thought to digest host hyaluronan into immunosuppressive disaccharides that dampen TLR2/4 signaling, leading to increased bacterial dissemination and adverse outcomes. In this study, we show that GBS HylB mediates immune suppression and promotes bacterial infection during pregnancy that requires TLR2, TLR4, and IL-10. Understanding the interaction between host and bacterial factors can inform future therapeutic strategies to mitigate GBS infections.

Gestational Age-Dependent Regulation of Transthyretin in Mice during Pregnancy

Our prior studies have shown that protein misfolding and aggregation in the placenta are linked to the development of preeclampsia, a severe pregnancy complication. We identified transthyretin (TTR) as a key component of the aggregated protein complex. However, the regulation of native TTR in normal pregnancy remains unclear. In this study, we found that pregnant mice exhibited a remarkable and progressive decline in serum TTR levels through gestational day (gd) 12-14, followed by an increase in late pregnancy and postpartum. Meanwhile, serum albumin levels showed a modest but statistically significant increase throughout gestation. TTR protein and mRNA levels in the liver, a primary source of circulating TTR, mirrored the changes observed in serum TTR levels during gestation. Intriguingly, a similar pattern of TTR alteration was also observed in the serum of pregnant women and pregnant interleukin-10-knockout (IL-10-/-) mice with high inflammation background. In non-pregnant IL-10-/- mice, serum TTR levels were significantly lower than those in age-matched wild-type mice. Administration of IL-10 to non-pregnant IL-10-/- mice restored their serum TTR levels. Notably, dysregulation of TTR resulted in fewer implantation units, lower fetal weight, and smaller litter sizes in human TTR-overexpressing transgenic mice. Thus, TTR may play a pivotal role as a crucial regulator in normal pregnancy, and inflammation during pregnancy may contribute to the downregulation of serum TTR presence.

The protective effect of magnesium sulfate on placental inflammation via suppressing the NF-κB pathway in a preeclampsia-like rat model

Abnormal placental inflammation has a role in the pathophysiology of preeclampsia. Magnesium sulfate (MgSO₄) has anti-inflammatory properties and is a fetal neuroprotective agent. MgSO₄ is often used to treat severe preeclampsia; however, the specificmechanisms of action underlyingthistherapeutic effect remain unclear. The objective of this study was to investigate the effects of MgSO₄ (270 mg/kg) on placental inflammation in a rat model of lipopolysaccharide (LPS; 1.0 µg/kg)-induced preeclampsia. Compared to normal pregnant rats, LPS-treated pregnant rats had higher blood pressure, proteinuria, and expression of the anti-angiogenic factor sFlt-1 and the pro-inflammatory factors interleukin-1β (IL-1β) and IL-12 in placental tissue. LPS-treated pregnant rats had placental insufficiency, poor fetal outcomes, and significantly decreased expression of the anti-inflammatory factors apolipoprotein E (APOE) and IL-10 in placental tissue. MgSO₄ treatment had favorable effects on maternal and fetal outcomes. MgSO₄ treatment improved placental function by repressing an exaggerated inflammatory response in the placenta and promoting angiogenesis via the NF-κB pathway. These findings suggest MgSO₄ has a potential role in the prevention of preeclampsia and in the treatment of mild and moderate preeclampsia.

Mendelian randomization study reveals a causal relationship between rheumatoid arthritis and risk for pre-eclampsia

Background

Epidemiological observational studies have investigated the relationship between rheumatoid arthritis(RA) and pre-eclampsia, but no consistent conclusions were obtained due to various limitations. Hence, we conducted a two-sample mendelian randomization analysis to evaluate the potential causal effect of RA on pre-eclampsia.

Methods

Summary-level statistics for RA were derived from a large-scale meta-analysis of datasets of genome-wide association studies(GWAS) which involved 14,361 cases and 43,923 controls. Moreover, summary statistics for pre-eclampsia or eclampsia were sourced from the Finn biobank which contained 3,903 cases and 114,735 controls. The inverse variance weighting (IVW) as well as other four effective methods including MR-Egger, weighted median, weighted mode, and simple mode were applied to deduce the potential causal relationships between RA and pre-eclampsia comprehensively.

Results

The two-sample MR analysis suggested a strong causal relationship between RA and pre-eclampsia[OR,1.05;95%CI, 1.01-1.09;p<0.05]. The OR estimates obtained from the weighted mode[OR,1.09;95%CI,1.03-1.15;p<0.01] and weighted median[OR,1.07;95%CI, 1.01-1.14;p<0.05] were similar to those from the IVW method, but there was no significant association observed in MR Egger and simple mode analysis.

Conclusion

This MR analysis provides evidence of a positive causal association between RA and pre-eclampsia genetically. Our findings highlight the importance of more intensive prenatal care and early intervention among pregnant women with RA to prevent potential adverse obstetric outcomes. Moreover, our study provides clues for risk factor identification and early prediction of pre-eclampsia.

Evidence From Human Placenta, Endoplasmic Reticulum-Stressed Trophoblasts, and Transgenic Mice Links Transthyretin Proteinopathy to Preeclampsia

BACKGROUND

We have demonstrated that protein aggregation plays a pivotal role in the pathophysiology of preeclampsia and identified several aggregated proteins in the circulation of preeclampsia patients, the most prominent of which is the serum protein TTR (transthyretin). However, the mechanisms that underlie protein aggregation remain poorly addressed.

METHODS

We examined TTR aggregates in hypoxia/reoxygenation-exposed primary human trophoblasts (PHTs) and the preeclampsia placenta using complementary approaches, including a novel protein aggregate detection assay. Mechanistic analysis was performed in hypoxia/reoxygenation-exposed PHTs and Ttr transgenic mice overexpressing transgene-encoded wild-type human TTR or Ttr^-/- mice. High-resolution ultrasound analysis was used to measure placental blood flow in pregnant mice.

RESULTS

TTR aggregation was inducible in PHTs and the TCL-1 trophoblast cell line by endoplasmic reticulum stress inducers or autophagy-lysosomal disruptors. PHTs exposed to hypoxia/reoxygenation showed increased intracellular BiP (binding immunoglobulin protein), phosphorylated IRE1α (inositol-requiring enzyme-1α), PDI (protein disulfide isomerase), and Ero-1, all markers of the unfolded protein response, and the apoptosis mediator caspase-3. Blockade of IRE1α inhibited hypoxia/reoxygenation-induced upregulation of Ero-1 in PHTs. Excessive unfolded protein response activation was observed in the early-onset preeclampsia placenta. Importantly, pregnant human TTR mice displayed aggregated TTR in the junctional zone of the placenta and severe preeclampsia-like features. High-resolution ultrasound analysis revealed low blood flow in uterine and umbilical arteries in human TTR mice compared with control mice. However, Ttr^-/- mice did not show any pregnancy-associated abnormalities.

CONCLUSIONS

These observations in the preeclampsia placenta, cultured trophoblasts, and Ttr transgenic mice indicate that TTR aggregation is an important causal contributor to preeclampsia pathophysiology.

Animal Models of Cardiovascular Complications of Pregnancy

Cardiovascular complications of pregnancy have risen substantially over the past decades, and now account for the majority of pregnancy-induced maternal deaths, as well as having substantial long-term consequences on maternal cardiovascular health. The causes and pathophysiology of these complications remain poorly understood, and therapeutic options are limited. Preclinical models represent a crucial tool for understanding human disease. We review here advances made in preclinical models of cardiovascular complications of pregnancy, including preeclampsia and peripartum cardiomyopathy, with a focus on pathological mechanisms elicited by the models and on relevance to human disease.

Hypoxia-Reoxygenation Impairs Autophagy-Lysosomal Machinery in Primary Human Trophoblasts Mimicking Placental Pathology of Early-Onset Preeclampsia

We have previously described that placental activation of autophagy is a central feature of normal pregnancy, whereas autophagy is impaired in preeclampsia (PE). Here, we show that hypoxia-reoxygenation (H/R) treatment dysregulates key molecules that maintain autophagy-lysosomal flux in primary human trophoblasts (PHTs). Ultrastructural analysis using transmission electron microscopy reveals a significant reduction in autophagosomes and autolysosomes in H/R-exposed PHTs. H/R-induced accumulation of protein aggregates follows a similar pattern that occurs in PHTs treated with a lysosomal disruptor, chloroquine. Importantly, the placenta from early-onset PE deliveries exhibits the same features as seen in H/R-treated PHTs. Taken together, our results indicate that H/R disrupts autophagic machinery in PHTs and that impaired autophagy in the placenta from early-onset PE deliveries mimics the events in H/R-treated PHTs. Notably, assessment of key regulators at each stage of autophagic processes, especially lysosomal integrity, and verification of autophagic ultrastructure are essential for an accurate evaluation of autophagy activity in human trophoblasts and placental tissue from PE deliveries.

Manipulating CD4+ T Cell Pathways to Prevent Preeclampsia

Preeclampsia (PreE) is a placental disorder characterized by hypertension (HTN), proteinuria, and oxidative stress. Individuals with PreE and their children are at an increased risk of serious short- and long-term complications, such as cardiovascular disease, end-organ failure, HTN, neurodevelopmental disorders, and more. Currently, delivery is the only cure for PreE, which remains a leading cause of morbidity and mortality among pregnant individuals and neonates. There is evidence that an imbalance favoring a pro-inflammatory CD4+ T cell milieu is associated with the inadequate spiral artery remodeling and subsequent oxidative stress that prime PreE's clinical symptoms. Immunomodulatory therapies targeting CD4+ T cell mechanisms have been investigated for other immune-mediated inflammatory diseases, and the application of these prevention tactics to PreE is promising, as we review here. These immunomodulatory therapies may, among other things, decrease tumor necrosis factor alpha (TNF-α), cytolytic natural killer cells, reduce pro-inflammatory cytokine production [e.g. interleukin (IL)-17 and IL-6], stimulate regulatory T cells (Tregs), inhibit type 1 and 17 T helper cells, prevent inappropriate dendritic cell maturation, and induce anti-inflammatory cytokine action [e.g. IL-10, Interferon gamma (IFN-γ)]. We review therapies including neutralizing monoclonal antibodies against TNF-α, IL-17, IL-6, and CD28; statins; 17-hydroxyprogesterone caproate, a synthetic hormone; adoptive exogenous Treg therapy; and endothelin-1 pathway inhibitors. Rebalancing the maternal inflammatory milieu may allow for proper spiral artery invasion, placentation, and maternal tolerance of foreign fetal/paternal antigens, thereby combatting early PreE pathogenesis.

A prospective cohort study providing insights for markers of adverse pregnancy outcome in older mothers

Background

Advanced maternal age (≥35 years) is associated with increased rates of adverse pregnancy outcome. Better understanding of underlying pathophysiological processes may improve identification of older mothers who are at greatest risk. This study aimed to investigate changes in oxidative stress and inflammation in older women and identify clinical and biochemical predictors of adverse pregnancy outcome in older women.

Methods

The Manchester Advanced Maternal Age Study (MAMAS) was a multicentre, observational, prospective cohort study of 528 mothers. Participants were divided into three age groups for comparison 20–30 years (n = 154), 35–39 years (n = 222) and ≥ 40 years (n = 152). Demographic and medical data were collected along with maternal blood samples at 28 and 36 weeks’ gestation. Multivariable analysis was conducted to identify variables associated with adverse outcome, defined as one or more of: small for gestational age (< 10th centile), FGR (<5th centile), stillbirth, NICU admission, preterm birth < 37 weeks’ gestation or Apgar score < 7 at 5 min. Biomarkers of inflammation, oxidative stress and placental dysfunction were quantified in maternal serum. Univariate and multivariable logistic regression was used to identify associations with adverse fetal outcome.

Results

Maternal smoking was associated with adverse outcome irrespective of maternal age (Adjusted Odds Ratio (AOR) 4.22, 95% Confidence Interval (95%CI) 1.83, 9.75), whereas multiparity reduced the odds (AOR 0.54, 95% CI 0.33, 0.89). In uncomplicated pregnancies in older women, lower circulating anti-inflammatory IL-10, IL-RA and increased antioxidant capacity (TAC) were seen. In older mothers with adverse outcome, TAC and oxidative stress markers were increased and levels of maternal circulating placental hormones (hPL, PlGF and sFlt-1) were reduced (p < 0.05). However, these biomarkers only had modest predictive accuracy, with the largest area under the receiver operator characteristic (AUROC) of 0.74 for placental growth factor followed by TAC (AUROC = 0.69).

Conclusions

This study identified alterations in circulating inflammatory and oxidative stress markers in older women with adverse outcome providing preliminary evidence of mechanistic links. Further, larger studies are required to determine if these markers can be developed into a predictive model of an individual older woman’s risk of adverse pregnancy outcome, enabling a reduction in stillbirth rates whilst minimising unnecessary intervention.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-04178-6.

Etiological Value of Sterile Inflammation in Preeclampsia: Is It a Non-Infectious Pregnancy Complication?

Understanding of sterile inflammation and its associated biological triggers and diseases is still at the elementary stage. This becomes more warranted in cases where infections are not associated with the pathology. Detrimental effects of bacterial and viral infections on the immune responses at the maternal-fetal interface as well as pregnancy outcomes have been well documented. However, an infection-induced etiology is not thought to be a major contributing component to severe pregnancy complications such as preeclampsia (PE) and gestational diabetes. How is then an inflammatory signal thought to be associated with these pregnancy complications? It is not clear what type of inflammation is involved in the onset of PE-like features. We opine that sterile inflammation regulated by the inflammasome-gasdermins-caspase-1 axis is a contributory factor to the onset of PE. We hypothesize that increased production and release of damage-associated molecular patterns (DAMPs) or Alarmins such as high-mobility group box1 (HMGB1), cell-free fetal DNA, uric acid, the NOD-like receptor pyrin-containing receptor 3 (NLRP3) inflammasome, IL-1β and IL-18 occur in the PE placenta. Some of these molecules have already been observed in the placenta from women with PE. Mechanistically, emerging evidence has demonstrated that excessive placental endoplasmic reticulum (ER) stress, impaired autophagy and gasdermine D (GSDMD)-mediated intrinsic pyroptosis are key events that contribute to systemic sterile inflammation in patients with PE, especially early-onset PE (e-PE). In this review, we highlight the advances on the roles of sterile inflammation and inflammatory signaling cascades involving ER stress, autophagy deficiency and pyroptosis in PE pathophysiology. Deciphering the mechanisms underlying these inflammatory pathways may provide potential diagnostic biomarkers and facilitate the development of therapeutic strategies to treat this devastating disease.

Size-controlled human adipose-derived stem cell spheroids hybridized with single-segmented nanofibers and their effect on viability and stem cell differentiation

BACKGROUND

Fabrication of three-dimensional stem cell spheroids have been studied to improve stem cell function, but the hypoxic core and limited penetration of nutrients and signaling cues to the interior of the spheroid were challenges. The incorporation of polymers such as silica and gelatin in spheroids resulted in relatively relaxed assembly of composite spheroids, and enhancing transport of nutrient and biological gas. However, because of the low surface area between cells and since the polymers were heterogeneously distributed throughout the spheroid, these polymers cannot increase the cell to extracellular matrix interactions needed to support differentiation.

METHODS

We developed the stem cell spheroids that incorporate poly(ι-lactic acid) single-segmented fibers synthesized by electrospinning and physical and chemical fragmentation. The proper mixing ratio was 2000 cells/μg fibers (average length of the fibers was 50 μm - 100 μm). The SFs were coated with polydopamine to increase cell binding affinity and to synthesize various-sized spheroids. The function of spheroids was investigated by in vitro analysis depending on their sizes. For statistical analysis, Graphpad Prism 5 software (San Diego, CA, USA) was used to perform one-way analysis of variance ANOVA with Tukey's honest significant difference test and a Student's t-test (for two variables) (P < 0.05).

RESULTS

Spheroids of different sizes were created by modulating the amount of cells and fibers (0.063 mm2-0.322 mm2). The fibers in the spheroid were homogenously distributed and increased cell viability, while cell-only spheroids showed a loss of DNA contents, internal degradation, and many apoptotic signals. Furthermore, we investigated stemness and various functions of various-sized fiber-incorporated spheroids. In conclusion, the spheroid with the largest size showed the greatest release of angiogenic factors (released VEGF: 0.111 ± 0.004 pg/ng DNA), while the smallest size showed greater effects of osteogenic differentiation (mineralized calcium: 18.099 ± 0.271 ng/ng DNA).

CONCLUSION

The spheroids incorporating polydopamine coated single-segmented fibers showed enhanced viability regardless of sizes and increased their functionality by regulating the size of spheroids which may be used for various tissue reconstruction and therapeutic applications.

Placental hypoxia: What have we learnt from small animal models?

Intrauterine hypoxia is a feature of pregnancy complications, both at high altitude and sea level. To understand the placental response to reduced oxygen availability, small animal models of maternal inhalation hypoxia (MIH) or reduced uterine perfusion pressure (RUPP) may be utilised. The aim of this review was to compare the findings of those studies to identify the role of oxygen availability in adapting placental structural and functional phenotypes in relation to fetal outcome. It also sought to explore the evidence for the involvement of particular genes and protein signalling pathways in the placenta in mediating hypoxia driven alterations. The data available demonstrate that both MIH and RUPP can induce placental hypoxia, which affects placental structure and vascularity, as well as glucose, amino acid, calcium and possibly lipid transport capacity. In addition, changes have been observed in HIF, VEGF, insulin/IGF2, AMPK, mTOR, PI3K and PPARγ signalling, which may be key in linking together observed phenotypes under conditions of placental hypoxia. Many different manipulations have been examined, with varied outcomes depending on the intensity, timing and duration of the insult. Some manipulations have detrimental effects on placental phenotype, viability and fetal growth, whereas in others, the placenta appears to adapt to uphold fetal growth despite the challenge of low oxygen. Together these data suggest a complex response of the placenta to reduced oxygen availability, which links to changes in fetal outcomes. However, further work is required to explore the role of fetal sex, altered maternal physiology and placental molecular mechanisms to fully understand placental responses to hypoxia and their relevance for pregnancy outcome.

Considerations to Model Heart Disease in Women with Preeclampsia and Cardiovascular Disease

Preeclampsia is a multifactorial cardiovascular disorder diagnosed after 20 weeks of gestation, and is the leading cause of death for both mothers and babies in pregnancy. The pathophysiology remains poorly understood due to the variability and unpredictability of disease manifestation when studied in animal models. After preeclampsia, both mothers and offspring have a higher risk of cardiovascular disease (CVD), including myocardial infarction or heart attack and heart failure (HF). Myocardial infarction is an acute myocardial damage that can be treated through reperfusion; however, this therapeutic approach leads to ischemic/reperfusion injury (IRI), often leading to HF. In this review, we compared the current in vivo, in vitro and ex vivo model systems used to study preeclampsia, IRI and HF. Future studies aiming at evaluating CVD in preeclampsia patients could benefit from novel models that better mimic the complex scenario described in this article.

Hypoxia and Mitochondrial Dysfunction in Pregnancy Complications

Hypoxia is a common and severe stress to an organism's homeostatic mechanisms, and hypoxia during gestation is associated with significantly increased incidence of maternal complications of preeclampsia, adversely impacting on the fetal development and subsequent risk for cardiovascular and metabolic disease. Human and animal studies have revealed a causative role of increased uterine vascular resistance and placental hypoxia in preeclampsia and fetal/intrauterine growth restriction (FGR/IUGR) associated with gestational hypoxia. Gestational hypoxia has a major effect on mitochondria of uteroplacental cells to overproduce reactive oxygen species (ROS), leading to oxidative stress. Excess mitochondrial ROS in turn cause uteroplacental dysfunction by damaging cellular macromolecules, which underlies the pathogenesis of preeclampsia and FGR. In this article, we review the current understanding of hypoxia-induced mitochondrial ROS and their role in placental dysfunction and the pathogenesis of pregnancy complications. In addition, therapeutic approaches selectively targeting mitochondrial ROS in the placental cells are discussed.

Maternal one carbon metabolism and interleukin-10 &-17 synergistically influence the mode of delivery in women with Early Onset Pre-Eclampsia

OBJECTIVE

Studies on One Carbon Metabolism (OCM), Interleukins-10 &-17 (IL-10/-17) & βhCG in pre-eclampsia and its delivery outcome (preterm birth) reveal contradictory results, attributed to clinical heterogeneity (early/late onset pre-eclampsia) or preterm/term birth. Disturbed OCM also influences IL-10 &-17 during pregnancy. We sought to investigate the synergism between OCM and IL-10/-17 mediated immune-regulation through βhCG in Early onset pre-eclampsia (EO-PE) patients, delivering preterm, among North Indian women.

STUDY DESIGN

Case-control study with a total of 399 pregnant women (EO-PE delivering preterm = 199; Normotensives delivering at term = 200). Maternal genotypes & biochemical estimations along with fetal genotypes on subset (n = 72) pertaining to OCM and IL-10/-17 regulation were assessed.

MAIN OUTCOME MEASURES

Association of 1) maternal plasma levels with EO-PE 2) maternal and fetal genotypes with EO-PE. 3) Effect of Hyper-homocysteinemia (surrogate of disturbed OCM) on differential immune regulation (IL10,-17, βhCG) in EO-PE and mode of delivery.

RESULTS

Hyper-homocysteinemia posed an increased risk of three folds for EO-PE. Both, folate and B12 deficiencies were associated with elevated homocysteine in EO-PE. Further, MTHFR 677TT homozygotes was present only in EO-PE indicating its detrimental role. However, maternal IL17-197AA genotype showed decreased risk for EO-PE. Furthermore, elevated maternal plasma IL-17 along with elevated IL-10 & βhCG were observed in EO-PE. Taken together, altered homocysteine metabolism was associated with high IL10 in EO-PE; and was more pronounced in spontaneous vaginal deliveries as compared to induced/caesarean section deliveries.

CONCLUSIONS

We report homocysteine mediated IL-10 &17 dysregulation and its influence on mode of delivery in EO-PE, possibly through initiation of cervical ripening. Further, these could serve potential biomarkers of EO-PE & its delivery outcome among vulnerable populations with similar nutritional & genetic predispositions.

Preeclamptic Women Have Decreased Circulating IL-10 (Interleukin-10) Values at the Time of Preeclampsia Diagnosis: Systematic Review and Meta-Analysis

A key immunomodulatory cytokine, IL-10 (interleukin-10), has been shown to be dysregulated in preeclampsia, a pregnancy-specific hypertensive disorder, further characterized by multi-system involvement. However, studies have reported inconsistent findings about circulating IL-10 levels in preeclamptic versus normotensive pregnancies. The aim of the present systematic review and meta-analysis was to assess circulating IL-10 levels in preeclamptic and normotensive pregnancies at 2 time points: before, and at the time of preeclampsia diagnosis. PubMED, EMBASE, and Web of Science databases were searched to include all published studies examining circulating IL-10 levels in preeclamptic and normotensive pregnancies. Differences in IL-10 levels were evaluated by standardized mean differences. Of 876 abstracts screened, 56 studies were included in the meta-analysis. Circulating IL-10 levels were not different before the time of active disease (standardized mean differences, -0.01 [95% CI, -0.11 to 0.08]; P=0.76). At the time of active disease, women with preeclampsia (n=1599) had significantly lower IL-10 levels compared with normotensive controls (n=1998; standardized mean differences, -0.79 [95% CI, -1.22 to -0.35]; P=0.0004). IL-10 levels were lower in both early/severe and late/mild forms of preeclampsia. Subgroup analysis revealed that IL-10 measurement methodology (ELISA or multiplex bead array) and the sample type (plasma or serum) significantly influenced the observed differences, with the use of sera paired with ELISA technology providing the best distinction in IL-10 levels between preeclamptic and normotensive pregnancies. These findings support the role of decreased IL-10 levels in the pathophysiology of preeclampsia. Future studies should address the therapeutic potential of IL-10 in preeclampsia.

Mechanisms of vascular dysfunction in the interleukin-10-deficient murine model of preeclampsia indicate nitric oxide dysregulation

Preeclampsia is a pregnancy-specific hypertensive disorder characterized by proteinuria, and vascular injury in the second half of pregnancy. We hypothesized that endothelium-dependent vascular dysfunction is present in a murine model of preeclampsia based on administration of human preeclamptic sera to interleukin-10-/- mice and studied mechanisms that underlie vascular injury. Pregnant wild type and IL-10-/- mice were injected with either normotensive or severe preeclamptic patient sera (sPE) during gestation. A preeclampsia-like phenotype was confirmed by blood pressure measurements; assessment of albuminuria; measurement of angiogenic factors; demonstration of foot process effacement and endotheliosis in kidney sections; and by accumulation of glycogen in placentas from IL-10-/- mice injected with sPE sera (IL-10-/-sPE). Vasomotor function of isolated aortas was assessed. The IL-10-/-sPE murine model demonstrated significantly augmented aortic contractions to phenylephrine and both impaired endothelium-dependent and, to a lesser extent, endothelium-independent relaxation compared to wild type normotensive mice. Treatment of isolated aortas with indomethacin, a cyclooxygenase inhibitor, improved, but failed to normalize contraction to phenylephrine to that of wild type normotensive mice, suggesting the additional contribution from nitric oxide downregulation and effects of indomethacin-resistant vasoconstricting factors. In contrast, indomethacin normalized relaxation of aortas derived from IL-10-/-sPE mice. Thus, our results identify the role of IL-10 deficiency in dysregulation of the cyclooxygenase pathway and vascular dysfunction in the IL-10-/-sPE murine model of preeclampsia and point towards a possible contribution of nitric oxide dysregulation. These compounds and related mechanisms may serve both as diagnostic markers and therapeutic targets for preventive and treatment strategies in preeclampsia.

Mechanisms of Key Innate Immune Cells in Early- and Late-Onset Preeclampsia

Preeclampsia is a complex cardiovascular disorder of pregnancy with underlying multifactorial pathogeneses; however, its etiology is not fully understood. It is characterized by the new onset of maternal hypertension after 20 weeks of gestation, accompanied by proteinuria, maternal organ damage, and/or uteroplacental dysfunction. Preeclampsia can be subdivided into early- and late-onset phenotypes (EOPE and LOPE), diagnosed before 34 weeks or from 34 weeks of gestation, respectively. Impaired placental development in early pregnancy and subsequent growth restriction is often associated with EOPE, while LOPE is associated with maternal endothelial dysfunction. The innate immune system plays an essential role in normal progression of physiological pregnancy and fetal development. However, inappropriate or excessive activation of this system can lead to placental dysfunction or poor maternal vascular adaptation and contribute to the development of preeclampsia. This review aims to comprehensively outline the mechanisms of key innate immune cells including macrophages, neutrophils, natural killer (NK) cells, and innate B1 cells, in normal physiological pregnancy, EOPE and LOPE. The roles of the complement system, syncytiotrophoblast extracellular vesicles and mesenchymal stem cells (MSCs) are also discussed in the context of innate immune system regulation and preeclampsia. The outlined molecular mechanisms, which represent potential therapeutic targets, and associated emerging treatments, are evaluated as treatments for preeclampsia. Therefore, by addressing the current understanding of innate immunity in the pathogenesis of EOPE and LOPE, this review will contribute to the body of research that could lead to the development of better diagnosis, prevention, and treatment strategies. Importantly, it will delineate the differences in the mechanisms of the innate immune system in two different types of preeclampsia, which is necessary for a more personalized approach to the monitoring and treatment of affected women.

Electroacupuncture Improves Blood Pressure in SHRs by Regulating the Immune Balance between Th17 and Treg

The present study investigated the effects of electroacupuncture on blood pressure in spontaneously hypertensive rats (SHRs) by regulating the immune balance of T helper 17 cells (Th17 cells) and regulatory T cells (Treg cells). This study investigated the role of electroacupuncture in the immune balance of SHRs using Western blot, flow cytometry, and ELISA techniques. Electroacupuncture significantly improved blood pressure, downregulated the expression of RORγt, and upregulated the expression of Foxp3, reduced the production of Th17 cells, promoted the production of Treg cells, reduced the secretion of IL-6 and IL-17, and increased the secretion of TGF-β1 and IL-10. These findings suggest that electroacupuncture therapy effectively improved the systolic blood pressure of SHRs, and its mechanism may be related to promotion of the immune balance between Th17 and Treg.

C-reactive protein, interleukin-6 and pre-eclampsia: large-scale evidence from the GenPE case-control study

Multiple small studies have suggested that women with pre-eclampsia present elevated levels of C-reactive protein (CRP) and interleukin-6 (IL-6). However, little is known regarding the source of this CRP and IL-6 increase. Therefore, the aim of this study was to evaluate the relationship between CRP and IL-6 levels with pre-eclampsia considering different confounding factors. Using data from a large Colombian case-control study (3,590 cases of pre-eclampsia and 4,564 normotensive controls), CRP and IL-6 levels were measured in 914 cases and 1297 controls. The association between maternal serum levels of CRP and IL-6 with pre-eclampsia risk was evaluated using adjusted logistic regression models. Pre-eclampsia was defined as presence of blood pressure ≥140/90 mmHg and proteinuria ≥300mg/24 h (or ≥1 + dipstick). There was no evidence of association between high levels of CRP and IL-6 with pre-eclampsia after adjusting for the following factors: maternal and gestational age, ethnicity, place and year of recruitment, multiple-pregnancy, socio-economic position, smoking, and presence of infections during pregnancy. The adjusted OR for 1SD increase in log-CRP and log-IL-6 was 0.96 (95%CI 0.85, 1.08) and 1.09 (95%CI 0.97, 1.22), respectively. Although previous reports have suggested an association between high CRP and IL-6 levels with pre-eclampsia, sample size may lack the sufficient power to draw robust conclusions, and this association is likely to be explained by unaccounted biases. Our results, the largest case-control study reported up to date, demonstrate that there is not a causal association between elevated levels of CRP and IL-6 and the presence of pre-eclampsia.

From animal models to patients: the role of placental microRNAs, miR-210, miR-126, and miR-148a/152 in preeclampsia

Placental microRNAs (miRNAs) regulate the placental transcriptome and play a pathological role in preeclampsia (PE), a hypertensive disorder of pregnancy. Three PE rodent model studies explored the role of placental miRNAs, miR-210, miR-126, and miR-148/152 respectively, by examining expression of the miRNAs, their inducers, and potential gene targets. This review evaluates the role of miR-210, miR-126, and miR-148/152 in PE by comparing findings from the three rodent model studies with in vitro studies, other animal models, and preeclamptic patients to provide comprehensive insight into genetic components and pathological processes in the placenta contributing to PE. The majority of studies demonstrate miR-210 is upregulated in PE in part driven by HIF-1α and NF-κBp50, stimulated by hypoxia and/or immune-mediated processes. Elevated miR-210 may contribute to PE via inhibiting anti-inflammatory Th2-cytokines. Studies report an up- and downregulation of miR-126, arguably reflecting differences in expression between cell types and its multifunctional capacity. MiR-126 may play a pro-angiogenic role by mediating the PI3K-Akt pathway. Most studies report miR-148/152 family members are upregulated in PE. Evidence suggests they may inhibit DNA methylation of genes involved in metabolic and inflammatory pathways. Given the genetic heterogeneity of PE, it is unlikely that a single placental miRNA is a suitable therapeutic target for all patients. Investigating miRNAs in PE subtypes in patients and animal models may represent a more appropriate approach going forward. Developing methods for targeting placental miRNAs and specific placental cell types remains crucial for research seeking to target placental miRNAs as a novel treatment for PE.

Animal Models of Preeclampsia: Causes, Consequences, and Interventions

Preeclampsia is a common pregnancy complication, affecting 2% to 8% of pregnancies worldwide, and is an important cause of both maternal and fetal morbidity and mortality. Importantly, although aspirin and calcium are able to prevent preeclampsia in some women, there is no cure apart from delivery of the placenta and fetus, often necessitating iatrogenic preterm birth. Preclinical models of preeclampsia are widely used to investigate the causes and consequences of preeclampsia and to evaluate safety and efficacy of potential preventative and therapeutic interventions. In this review, we provide a summary of the published preclinical models of preeclampsia that meet human diagnostic criteria, including the development of maternal hypertension, together with new-onset proteinuria, maternal organ dysfunction, and uteroplacental dysfunction. We then discuss evidence from preclinical models for multiple causal factors of preeclampsia, including those implicated in early-onset and late-onset preeclampsia. Next, we discuss the impact of exposure to a preeclampsia-like environment for later maternal and progeny health. The presence of long-term impairment, particularly cardiovascular outcomes, in mothers and progeny after an experimentally induced preeclampsia-like pregnancy, implies that later onset or reduced severity of preeclampsia will improve later maternal and progeny health. Finally, we summarize published intervention studies in preclinical models and identify gaps in knowledge that we consider should be targets for future research.

Pyroptosis is a critical inflammatory pathway in the placenta from early onset preeclampsia and in human trophoblasts exposed to hypoxia and endoplasmic reticulum stressors

Systemic manifestation of preeclampsia (PE) is associated with circulating factors, including inflammatory cytokines and damage-associated molecular patterns (DAMPs), or alarmins. However, it is unclear whether the placenta directly contributes to the increased levels of these inflammatory triggers. Here, we demonstrate that pyroptosis, a unique inflammatory cell death pathway, occurs in the placenta predominantly from early onset PE, as evidenced by elevated levels of active caspase-1 and its substrate or cleaved products, gasdermin D (GSDMD), IL-1β, and IL-18. Using cellular models mimicking pathophysiological conditions (e.g., autophagy deficiency, hypoxia, and endoplasmic reticulum (ER) stress), we observed that pyroptosis could be induced in autophagy-deficient human trophoblasts treated with sera from PE patients as well as in primary human trophoblasts exposed to hypoxia. Exposure to hypoxia elicits excessive unfolded protein response (UPR) and ER stress and activation of the NOD-like receptor pyrin-containing 3 (NLRP3) inflammasome in primary human trophoblasts. Thioredoxin-interacting protein (TXNIP), a marker for hyperactivated UPR and a crucial signaling molecule linked to NLRP3 inflammasome activation, is significantly increased in hypoxia-treated trophoblasts. No evidence was observed for necroptosis-associated events. Importantly, these molecular events in hypoxia-treated human trophoblasts are significantly observed in placental tissue from women with early onset PE. Taken together, we propose that placental pyroptosis is a key event that induces the release of factors into maternal circulation that possibly contribute to severe sterile inflammation and early onset PE pathology.

Cross-Talk between Oxidative Stress and Inflammation in Preeclampsia

The occurrence of hypertensive syndromes during pregnancy leads to high rates of maternal-fetal morbidity and mortality. Amongst them, preeclampsia (PE) is one of the most common. This review aims to describe the relationship between oxidative stress and inflammation in PE, aiming to reinforce its importance in the context of the disease and to discuss perspectives on clinical and nutritional treatment, in this line of research. Despite the still incomplete understanding of the pathophysiology of PE, it is well accepted that there are placental changes in pregnancy, associated with an imbalance between the production of reactive oxygen species and the antioxidant defence system, characterizing the placental oxidative stress that leads to an increase in the production of proinflammatory cytokines. Hence, a generalized inflammatory process occurs, besides the presence of progressive vascular endothelial damage, leading to the dysfunction of the placenta. There is no consensus in the literature on the best strategies for prevention and treatment of the disease, especially for the control of oxidative stress and inflammation. In view of the above, it is evident the important connection between oxidative stress and inflammatory process in the pathogenesis of PE, being that this disease is capable of causing serious implications on both maternal and fetal health. Reports on the use of anti-inflammatory and antioxidant compounds are analysed and still considered controversial. As such, the field is open for new basic and clinical research, aiming the development of innovative therapeutic approaches to prevent and to treat PE.

Upregulated ARRDC3 limits trophoblast cell invasion and tube formation and is associated with preeclampsia

OBJECTIVE

Bioinformatics analysis indicated that the arrestin ARRDC3 was upregulated in placental tissue from patients with preeclampsia (PE). The study aimed to confirm the finding by examining placenta samples from women with and without early-onset PE and to investigate ARRDC3 roles in trophoblast function.

METHODS

ARRDC3 expression level and localization in placental tissue were determined by Western blot, real-time quantitative PCR and immunohistochemistry. An in vitro hypoxia and an in vitro ischemia (hypoxia/reoxygenation) cell models were used to determine the hypoxic and ischemic effects on ARRDC3 expression in extravillous trophoblast-derived HTR/8SVneo cells and trophoblast cell activity. The role of ARRDC3 in HTR8/SVneo cell proliferation, invasion and tube formation in vitro was investigated by testing the effects of ARRDC3 gene overexpression or siRNA-based gene silencing.

RESULTS

ARRDC3 expression was significantly elevated in placental tissue from women with early-onset PE compared to preterm birth pregnancies. ARRDC3 protein was localized in human placental trophoblasts. Hypoxia and ischemia both enhanced ARRDC3 protein expression in HTR8/SVneo cells. Hypoxia altered trophoblast cell activities. Overexpression of ARRDC3 in HTR8/SVneo cells suppressed cell invasion and tube formation. ARRDC3 gene silencing, by contrast, promoted invasion and tube formation under hypoxic conditions.

CONCLUSION

ARRDC3 was highly expressed in placental tissues of PE patients and directly affected biological activities of trophoblasts under hypoxic conditions. In regulation of ARRDC3- protein expression, ischemia (hypoxia/reoxygenation) are also important. These findings suggest that ARRDC3 may play a clinically significant role in the pathogenesis of PE.

Pre-eclampsia in a mother and programming of the child’s cardiovascular health

The authors present a review of the literature devoted to the problem of programming the formation of the cardiovascular system structure and function in children born from mothers with preeclampsia. These children are at high risk of developing cardiovascular diseases. Pre-eclampsia is caused by the endothelium dysfunction, deregulation of the immune and inflammatory factors during pregnancy. Experimental studies identify these factors as key epigenetic factors programming the condition of the cardiovascular system of the offspring. The modern concept of intrauterine programming, describing this phenomenon, focuses on three main areas of research: experimental models simulating the intrauterine environment with preeclampsia; research of the pathological phenotype formation under the influence of these factors; epigenetic studies of the influence of preeclampsia on the cardiovascular system functioning. The article discusses the perspectives of epigenetic programming prevention.

Obstructive Sleep Apnea in Pregnant Women: A Review of Pregnancy Outcomes and an Approach to Management

Among obese pregnant women, 15%-20% have obstructive sleep apnea (OSA) and this prevalence increases along with body mass index and in the presence of other comorbidities. Prepregnancy obesity and pregnancy-related weight gain are certainly risk factors for sleep-disordered breathing in pregnancy, but certain physiologic changes of pregnancy may also increase a woman's risk of developing or worsening OSA. While it has been shown that untreated OSA in postmenopausal women is associated with a range of cardiovascular, pulmonary, and metabolic comorbidities, a body of literature is emerging that suggests OSA may also have serious implications for the health of mothers and fetuses during and after pregnancy. In this review, we discuss the following: pregnancy as a vulnerable period for the development or worsening of OSA; the associations between OSA and maternal and fetal outcomes; the current screening modalities for OSA in pregnancy; and current recommendations regarding peripartum management of OSA.

Hypertensive disorders of pregnancy: Strategy to develop clinical peptide biomarkers for more accurate evaluation of the pathophysiological status of this syndrome

Hypertensive disorders of pregnancy (HDP) is the most common and widely known as serious complication of pregnancy. As this syndrome is a major leading cause of maternal, fetal, and neonatal morbidity/mortality worldwide, many studies have sought to identify candidate molecules as potential disease biomarkers (DBMs) for use in clinical examinations. Accumulating evidence over the past 2 decades that the many proteolytic peptides appear in human humoral fluids, including peripheral blood, in association with an individual's health condition. This review provides the potential utility of peptidomic analysis for monitoring for pathophysiological status in HDP, and presents an overview of current status of peptide quantification technology. Especially, the technical limitations of the methods used for DBM discovery in the blood are discussed.

microRNA-520c-3p suppresses NLRP3 inflammasome activation and inflammatory cascade in preeclampsia by downregulating NLRP3

BACKGROUND

The pathogenesis of preeclampsia (PE) is suggested to be a consequence of inflammation. Previously conducted investigations on nod-like receptor pyrin domain-containing 3 (NLRP3) have shed light to its crucial role in PE. Furthermore, microRNA-520c-3p (miR-520c-3p) is observed to be implicated in inflammation. Therefore, the current study aimed to explore the role of miR-520c-3p in inflammatory cascade of PE by targeting NLRP3.

METHODS

Microarray analyses were performed to screen differentially expressed genes associated with PE, and the potential relationship between miR-520c-3p and NLRP3 was analyzed. PE and normal placenta tissues were collected to determine the levels of inflammatory cytokines (IL-18, IL-33, IL-1β, IL-10, and TNF-α), miR-520c-3p and NLRP3. Hypoxic HTR8/SVneo cells were transfected with oe-NLRP3, si-NLRP3 or miR-520c-3p mimic to elucidate the functional role of NLRP3 or miR-520c-3p in the inflammatory cascade in PE, followed by the evaluation of levels of inflammatory cytokines and NLRP3 inflammasomes (NLRP3, ASC and caspase-1). Additionally, the HTR8/SVneo cell migration and invasion were evaluated.

RESULTS

An upregulation of NLRP3, IL-18, IL-1β and TNF-α, and downregulation of miR-520c-3p, IL-33 and IL-10 were observed in PE placenta tissues. NLRP3 was found to be a target gene of miR-520c-3p. HTR8/SVneo cells after hypoxia transfected with si-NLRP3 or miR-520c-3p mimic exhibited decreased levels of inflammatory cytokines and NLRP3 inflammasomes, in addition to increased IL-10 and IL-33 levels. Moreover, enhanced migration and invasion abilities were observed in cells transfected with si-NLRP3.

CONCLUSION

Collectively, miR-520c-3p could potentially inhibit NLRP3 inflammasome activation and inflammatory cascade in PE by downregulating NLRP3, highlighting the potential of miR-520c-3p as a therapeutic target for PE treatment.

Preeclampsia: Disease biology and burden, its management strategies with reference to India

Preeclampsia is the cause of significant maternal and fetal mortality and morbidity. It is characterized by new-onset hypertension and proteinuria after 20 weeks of gestation. Preeclamptic women and children born from preeclamptic pregnancies are at greater risk to develop severe cardiovascular complications and metabolic syndromes later in life. The incidence of preeclampsia is estimated to be seven times higher in developing countries as compared to the developed countries. This review summarizes the pathophysiology of preeclampsia, emerging new hypothesis of its origin, risk factors that make women susceptible to developing preeclampsia and the potential of various biomarkers being studied to predict preeclampsia. The health care of developing countries is continuously challenged by substantial burden of maternal and fetal mortality. India despite being a fast developing country, is still far behind in achieving the required maternal mortality rates as per Millennium Development Goals set by the World Health Organization. Further, this review discusses the prevalence of preeclampsia in India, health facilities to manage preeclampsia, current guidelines and protocols followed and government policies to combat this complication in Indian condition.

Adrenergic receptor blockade attenuates placental ischemia-induced hypertension

Preeclampsia (PE), a disorder of new-onset maternal hypertension and vascular dysfunction during pregnancy, is thought to be linked to placental ischemia-induced release of prohypertensive factors and reductions of vasoprotective factors in the maternal circulation. Although markers of sympathetic nervous activity are elevated in experimental models of placental ischemia-induced hypertension and women with PE compared with their normal pregnant counterparts, the importance of adrenergic receptor signaling in the development of hypertension in PE is unknown. Therefore, we tested the hypothesis that adrenergic receptor blockade attenuates the development of placental ischemia-induced hypertension in rats. Wistar Hannover rats underwent reduced uterine perfusion pressure (RUPP) or Sham surgeries on gestational day 14. By day 19, mean arterial blood pressure (MAP) was increased in RUPP over Sham rats. Groups of RUPP and Sham pregnant rats received terazosin and propranolol (3 mg/kg per day of each via subcutaneous osmotic minipump) to block α1- and β-adrenergic receptors, respectively, beginning on gestational day 14. Adrenergic blockade significantly attenuated the development of hypertension in the RUPP rats with a slight blood pressure-lowering response in the Sham, normal pregnant rats by day 19. In conclusion, these data implicate that placental ischemia-induced hypertension involves adrenergic receptor signaling to promote increases in blood pressure during PE.

Integrated Systems Biology Approach Identifies Novel Maternal and Placental Pathways of Preeclampsia

Preeclampsia is a disease of the mother, fetus, and placenta, and the gaps in our understanding of the complex interactions among their respective disease pathways preclude successful treatment and prevention. The placenta has a key role in the pathogenesis of the terminal pathway characterized by exaggerated maternal systemic inflammation, generalized endothelial damage, hypertension, and proteinuria. This sine qua non of preeclampsia may be triggered by distinct underlying mechanisms that occur at early stages of pregnancy and induce different phenotypes. To gain insights into these molecular pathways, we employed a systems biology approach and integrated different "omics," clinical, placental, and functional data from patients with distinct phenotypes of preeclampsia. First trimester maternal blood proteomics uncovered an altered abundance of proteins of the renin-angiotensin and immune systems, complement, and coagulation cascades in patients with term or preterm preeclampsia. Moreover, first trimester maternal blood from preterm preeclamptic patients in vitro dysregulated trophoblastic gene expression. Placental transcriptomics of women with preterm preeclampsia identified distinct gene modules associated with maternal or fetal disease. Placental "virtual" liquid biopsy showed that the dysregulation of these disease gene modules originates during the first trimester. In vitro experiments on hub transcription factors of these gene modules demonstrated that DNA hypermethylation in the regulatory region of ZNF554 leads to gene down-regulation and impaired trophoblast invasion, while BCL6 and ARNT2 up-regulation sensitizes the trophoblast to ischemia, hallmarks of preterm preeclampsia. In summary, our data suggest that there are distinct maternal and placental disease pathways, and their interaction influences the clinical presentation of preeclampsia. The activation of maternal disease pathways can be detected in all phenotypes of preeclampsia earlier and upstream of placental dysfunction, not only downstream as described before, and distinct placental disease pathways are superimposed on these maternal pathways. This is a paradigm shift, which, in agreement with epidemiological studies, warrants for the central pathologic role of preexisting maternal diseases or perturbed maternal-fetal-placental immune interactions in preeclampsia. The description of these novel pathways in the "molecular phase" of preeclampsia and the identification of their hub molecules may enable timely molecular characterization of patients with distinct preeclampsia phenotypes.

Long-term high altitude hypoxia during gestation suppresses large conductance Ca2+ -activated K+ channel function in uterine arteries: a causal role for microRNA-210

KEY POINTS

Gestational hypoxia represses ten-eleven translocation methylcytosine dioxygenase 1 (TET1) expression in uterine arteries, which is recovered by inhibiting endogenous miR-210. Inhibition of miR-210 rescues BK_Ca channel expression and current in uterine arteries of pregnant animals acclimatized to high altitude hypoxia in a TET-dependent manner. miR-210 blockade restores BK_Ca channel-mediated relaxations and attenuates pressure-dependent myogenic tone in uterine arteries of pregnant animals acclimatized to high altitude.

ABSTRACT

Gestational hypoxia at high altitude has profound adverse effects on the uteroplacental circulation, and is associated with increased incidence of preeclampsia and fetal intrauterine growth restriction. Previous studies demonstrated that suppression of large-conductance Ca²⁺ -activated K⁺ (BK_Ca ) channel function played a critical role in the maladaptation of uteroplacental circulation caused by gestational hypoxia. Yet, the mechanisms underlying gestational hypoxia-induced BK_Ca channel repression remain undetermined. The present study investigated a causal role of microRNA-210 (miR-210) in hypoxia-mediated repression of BK_Ca channel expression and function in uterine arteries using a sheep model. The results revealed that gestational hypoxia significantly decreased ten-eleven translocation methylcytosine dioxygenase 1 (TET1) expression in uterine arteries, which was recovered by inhibiting endogenous miR-210 with miR-210 locked nucleic acid (miR-210-LNA). Of importance, miR-210-LNA restored BK_Ca channel β1 subunit expression in uterine arteries, which was blocked by a competitive TET inhibitor, fumarate, thus functionally linking miR-210 to the TET1-BK_Ca channel cascade. In addition, miR-210-LNA reversed hypoxia-mediated suppression of BK_Ca channel function and rescued the effect of steroid hormones in upregulating BK_Ca channel expression and function in uterine arteries, which were also ablated by fumarate. Collectively, the present study demonstrates a causative effect of miR-210 in the downregulation of TET1 and subsequent repression of BK_Ca channel expression and function, providing a novel mechanistic insight into the regulation of BK_Ca channel function and the molecular basis underlying the maladaptation of uterine vascular function in gestational hypoxia.

Hypoxia and Placental Development

Hemochorial placentation is orchestrated through highly regulated temporal and spatial decisions governing the fate of trophoblast stem/progenitor cells. Trophoblast cell acquisition of specializations facilitating invasion and uterine spiral artery remodeling is a labile process, sensitive to the environment, and represents a process that is vulnerable to dysmorphogenesis in pathologic states. Hypoxia is a signal guiding placental development, and molecular mechanisms directing cellular adaptations to low oxygen tension are integral to trophoblast cell differentiation and placentation. Hypoxia can also be used as an experimental tool to investigate regulatory processes controlling hemochorial placentation. These developmental processes are conserved in mouse, rat, and human placentation. Consequently, elements of these developmental events can be modeled and hypotheses tested in trophoblast stem cells and in genetically manipulated rodents. Hypoxia is also a consequence of a failed placenta, yielding pathologies that can adversely affect maternal adjustments to pregnancy, fetal health, and susceptibility to adult disease. The capacity of the placenta for adaptation to environmental challenges highlights the importance of its plasticity in safeguarding a healthy pregnancy. Birth Defects Research 109:1309-1329, 2017.© 2017 Wiley Periodicals, Inc.

Management of Obstructive Sleep Apnea in Pregnancy

The spectrum of sleep-disordered breathing (SDB) ranges from mild snoring to obstructive sleep apnea, the most severe form of SDB. Current recommendations are to treat these women with continuous positive airway pressure despite limited data. SDB in early and mid-pregnancy is associated with preeclampsia and gestational diabetes. Pregnant women with a diagnosis of obstructive sleep apnea at delivery were at significantly increased risk of having cardiomyopathy, congestive heart failure, pulmonary embolism, and in-hospital death. These effects were exacerbated in the presence of obesity. Postpartum, these women are at risk for respiratory suppression and should be monitored.

A review of the associations between obstructive sleep apnea and hypertensive disorders of pregnancy and possible mechanisms of disease

Obesity is prevalent among pregnant women in the United States; 15-20% of obese pregnant women have obstructive sleep apnea. The prevalence of obstructive sleep apnea increases along with body mass index, age and in the presence of other co-morbidities. Untreated obstructive sleep apnea in women is associated with a range of cardiovascular, pulmonary and metabolic co-morbidities; recent studies suggest that women with obstructive sleep apnea in pregnancy may be at significantly greater risk of entering pregnancy with chronic hypertension and/or of developing hypertensive disorders of pregnancy: gestational hypertension; preeclampsia; or eclampsia. This has serious public health implications; hypertensive disorders of pregnancy are a major cause of maternal and neonatal morbidity and mortality and are associated with a greater lifetime risk for cardiovascular disease. The mechanisms that associated obstructive sleep apnea with hypertensive disorders of pregnancy have not been defined, but several pathways are scientifically plausible. In this review, we will present a comprehensive literature review of the following: the associations between obstructive sleep apnea and hypertensive disorders of pregnancy; the proposed mechanisms that may connect obstructive sleep apnea and hypertensive disorders of pregnancy; and the effectiveness of treatment at mitigating these adverse outcomes.

The Role of Interleukin-10 in the Pathophysiology of Preeclampsia

PURPOSE OF REVIEW

The pathophysiology of preeclampsia is complex and not entirely understood. A key feature in preeclampsia development is an immunological imbalance that shifts the maternal immune response from one of tolerance towards one promoting chronic inflammation and endothelial dysfunction. As a key regulator of immunity, IL-10 not only has immunomodulatory activity, but also directly benefits vasculature and promotes successful cellular interactions at the maternal-fetal interface. Here we focus on the mechanisms by which the dysregulation of IL-10 may contribute to the pathophysiology of preeclampsia.

RECENT FINDINGS

Dysregulation of IL-10 has been demonstrated in various animal models of preeclampsia. Decreased IL-10 production in both placenta and peripheral blood mononuclear cells has been reported in human studies, but with inconsistent results. The significance of IL-10 in preeclampsia has shifted from a key biomarker to one with therapeutic potential. As such, a better understanding of the role of this cytokine in the pathophysiology of preeclampsia is of paramount importance.

Current model systems for the study of preeclampsia

Preeclampsia (PE) is a pregnancy complex disease, distinguished by high blood pressure and proteinuria, diagnosed after the 20th gestation week. Depending on the values of blood pressure, urine protein concentrations, symptomatology, and onset of disease there is a wide range of phenotypes, from mild forms developing predominantly at the end of pregnancy to severe forms developing in the early stage of pregnancy. In the worst cases severe forms of PE could lead to systemic endothelial dysfunction, eclampsia, and maternal and/or fetal death. Worldwide the fetal morbidity and mortality related to PE is calculated to be around 8% of the total pregnancies. PE still being an enigma regarding its etiology and pathophysiology, in general a deficient trophoblast invasion during placentation at first stage of pregnancy, in combination with maternal conditions are accepted as a cause of endothelial dysfunction, inflammatory alterations and appearance of symptoms. Depending on the PE multifactorial origin, several in vitro, in vivo, and in silico models have been used to evaluate the PE pathophysiology as well as to identify or test biomarkers predicting, diagnosing or prognosing the syndrome. This review focuses on the most common models used for the study of PE, including those related to placental development, abnormal trophoblast invasion, uteroplacental ischemia, angiogenesis, oxygen deregulation, and immune response to maternal-fetal interactions. The advances in mathematical and computational modeling of metabolic network behavior, gene prioritization, the protein-protein interaction network, the genetics of PE, and the PE prediction/classification are discussed. Finally, the potential of these models to enable understanding of PE pathogenesis and to evaluate new preventative and therapeutic approaches in the management of PE are also highlighted. Impact statement This review is important to the field of preeclampsia (PE), because it provides a description of the principal in vitro, in vivo, and in silico models developed for the study of its principal aspects, and to test emerging therapies or biomarkers predicting the syndrome before their evaluation in clinical trials. Despite the current advance, the field still lacking of new methods and original modeling approaches that leads to new knowledge about pathophysiology. The part of in silico models described in this review has not been considered in the previous reports.

Interleukin-10 rs1800871 (-819C/T) and ATA haplotype are associated with preeclampsia in a Tunisian population

OBJECTIVES

Interleukin-10 (IL-10) is implicated in several aspects of pregnancy. As genetic predisposition can be involved in the development of preeclampsia, the association between IL-10's promoter region polymorphisms and this pathology has been investigated, although with conflicting results. To date, only a small cohort study (total n = 40) has evaluated this association in the African continent, and none have been conducted in Tunisia. Hence, we evaluated the association between these polymorphisms and the risk of preeclampsia in a large Tunisian cohort.

STUDY DESIGN

345 preeclampsia patients and 300 controls were genotyped for the IL-10 promoter region variants -1082A/G, -819C/T and -592A/C using real-time PCR.

MAIN OUTCOME MEASURES

Differences in means were determined by Student's t-test, while intergroup significance was assessed by Pearson χ² or 2-way ANOVA. Genotypes were tested for Hardy-Weinberg equilibrium (HWE) in the control and cases. Logistic regression analysis was performed in order to determine the odds ratios and 95% confidence intervals associated with the linkage disequilibrium risk.

RESULTS

An increased frequency of the -819 T (minor) allele and the -819 T/T genotype was seen in preeclampsia cases. Also, three-locus haplotype (-1082AG/-819CT/-592AC) analysis identified the ATA haplotype as having a higher incidence in women with preeclampsia (OR = 1.48, 95% CI: 1.03-2.11) and this was confirmed by multivariate regression analysis (OR = 1.65, 95% CI: 1.13-2.43) after controlling for covariates.

CONCLUSIONS

We suggest that the IL-10 -819 T/T variant and the ATA haplotype, which are associated with low production of IL 10, represent genetic risk factors for preeclampsia in Tunisian women.

New Models of Pregnancy-Associated Hypertension

Pregnancy-associated hypertensive disorders are leading causes of maternal and fetal mortality. These include: pre-pregnancy hypertension that persists throughout gestation (chronic/preexisting hypertension), de novo hypertension that is diagnosed after 20 weeks of gestation and resolves after birth (gestational hypertension), de novo hypertension that is diagnosed after 20 weeks of gestation with or without proteinuria and end-organ damage (preeclampsia and eclampsia), and chronic hypertension with superimposed preeclampsia during gestation. Preeclampsia is the most severe form of these disorders. Animal models have been developed by employing surgical, genetic, and pharmacological approaches in order to recapitulate the maternal symptoms of preeclampsia and other hypertensive disorders of pregnancy. The scope of this brief review is to present an up-to-date synthesis of our knowledge of experimental models of pregnancy-associated hypertensive disorders. Novel models, defined in this review as characterized within the last 5 years, will be described and critically discussed. In this review, we will also discuss established experimental models of pregnancy-associated hypertensive disorders in the context of their contribution to new advances in our knowledge about the pathophysiology of these disorders and potential therapeutics. Emphasis will be placed on animal models of preeclampsia; however, models of other hypertensive disorders in pregnancy will also be reviewed.

Immune regulation of systemic hypertension, pulmonary arterial hypertension, and preeclampsia: shared disease mechanisms and translational opportunities

Systemic hypertension, preeclampsia, and pulmonary arterial hypertension (PAH) are diseases of high blood pressure in the systemic or pulmonary circulation. Beyond the well-defined contribution of more traditional pathophysiological mechanisms, such as changes in the renin-angiotensin-aldosterone system, to the development of these hypertensive disorders, there is substantial clinical evidence supporting an important role for inflammation and immunity in the pathogenesis of each of these three conditions. Over the last decade, work in small animal models, bearing targeted deficiencies in specific cytokines or immune cell subsets, has begun to clarify the immune-mediated mechanisms that drive changes in vascular structure and tone in hypertensive disease. By summarizing the clinical and experimental evidence supporting a contribution of the immune system to systemic hypertension, preeclampsia, and PAH, the current review highlights the cellular and molecular pathways that are common to all three hypertensive disorders. These mechanisms are centered on an imbalance in CD4⁺ helper T cell populations, defined by excessive Th17 responses and impaired T_reg activity, as well as the excessive activation or impairment of additional immune cell types, including macrophages, dendritic cells, CD8⁺ T cells, B cells, and natural killer cells. The identification of common immune mechanisms in systemic hypertension, preeclampsia, and PAH raises the possibility of new therapeutic strategies that target the immune component of hypertension across multiple disorders.

Gestational hypoxia disrupts the neonatal leptin surge and programs hyperphagia and obesity in male offspring in the Sprague-Dawley rat

The effect of gestational hypoxia on the neonatal leptin surge, development of hypothalamic arcuate nuclei (ARH) projections and appetite that could contribute to the programming of offspring obesity is lacking. We examined the effect of 12% O₂ from gestational days 15–19 in the Sprague-Dawley rat on post-weaning appetite, fat deposition by MRI, adipose tissue cytokine expression, the neonatal leptin surge, ARH response to exogenous leptin, and αMSH projections to the paraventricular nucleus (PVN) in response to a high fat (HFD) or control diet (CD) in male offspring. Normoxia (NMX) and Hypoxia (HPX) offspring exhibited increased food intake when fed a HFD from 5–8 weeks post-birth; HPX offspring on the CD had increased food intake from weeks 5–7 vs. NMX offspring on a CD. HPX offspring on a HFD remained hyperphagic through 23 weeks. Body weight were the same between offspring from HPX vs. NMX dams from 4–12 weeks of age fed a CD or HFD. By 14–23 weeks of age, HPX offspring fed the CD or HFD as well as male NMX offspring fed the HFD were heavier vs. NMX offspring fed the CD. HPX offspring fed a CD exhibited increased abdominal adiposity (MRI) that was amplified by a HFD. HPX offspring fed a HFD exhibited the highest abdominal fat cytokine expression. HPX male offspring had higher plasma leptin from postnatal day (PN) 6 through 14 vs. NMX pups. HPX offspring exhibited increased basal c-Fos labeled cells in the ARH vs. NMX pups on PN16. Leptin increased c-Fos staining in the ARH in NMX but not HPX offspring at PN16. HPX offspring had fewer αMSH fibers in the PVN vs. NMX offspring on PN16. In conclusion, gestational hypoxia impacts the developing ARH resulting in hyperphagia contributing to adult obesity on a control diet and exacerbated by a HFD.

Sex differences in ischaemic stroke: potential cellular mechanisms

Stroke remains a leading cause of mortality and disability worldwide. More women than men have strokes each year, in part because women live longer. Women have poorer functional outcomes, are more likely to need nursing home care and have higher rates of recurrent stroke compared with men. Despite continued advancements in primary prevention, innovative acute therapies and ongoing developments in neurorehabilitation, stroke incidence and mortality continue to increase due to the aging of the U.S.

POPULATION

Sex chromosomes (XX compared with XY), sex hormones (oestrogen and androgen), epigenetic regulation and environmental factors all contribute to sex differences. Ischaemic sensitivity varies over the lifespan, with females having an "ischaemia resistant" phenotype that wanes after menopause, which has recently been modelled in the laboratory. Pharmacological therapies for acute ischaemic stroke are limited. The only pharmacological treatment for stroke approved by the Food and Drug Administration (FDA) is tissue plasminogen activator (tPA), which must be used within hours of stroke onset and has a number of contraindications. Pre-clinical studies have identified a number of potentially efficacious neuroprotective agents; however, nothing has been effectively translated into therapy in clinical practice. This may be due, in part, to the overwhelming use of young male rodents in pre-clinical research, as well as lack of sex-specific design and analysis in clinical trials. The review will summarize the current clinical evidence for sex differences in ischaemic stroke, and will discuss sex differences in the cellular mechanisms of acute ischaemic injury, highlighting cell death and immune/inflammatory pathways that may contribute to these clinical differences.

IL-10 Dysregulation in Acute Mountain Sickness Revealed by Transcriptome Analysis

Acute mountain sickness (AMS), which may progress to life-threatening high-altitude cerebral edema, is a major threat to millions of people who live in or travel to high altitude. Although studies have revealed the risk factors and pathophysiology theories of AMS, the molecular mechanisms of it do not comprehensively illustrate. Here, we used a system-level methodology, RNA sequencing, to explore the molecular mechanisms of AMS at genome-wide level in 10 individuals. After exposure to high altitude, a total of 1,164 and 1,322 differentially expressed transcripts were identified in AMS and non-AMS groups, respectively. Among them, only 328 common transcripts presented between the two groups. Immune and inflammatory responses were overrepresented in participants with AMS, but not in non-AMS individuals. Anti-inflammatory cytokine IL10 and inflammation cytokines IF17F and CCL8 exhibited significantly different genetic connectivity in AMS compared to that of non-AMS individuals based on network analysis. IL10 was downregulated and both IF17F and CCL8 were upregulated in AMS individuals. Moreover, the serum concentration of IL10 significantly decreased in AMS patients after exposure to high altitude (p = 0.001) in another population (n = 22). There was a large negative correlation between the changes in IL10 concentration, r(22) = −0.52, p = 0.013, and Lake Louise Score. Taken together, our analysis provides unprecedented characterization of AMS transcriptome and identifies that genes involved in immune and inflammatory responses were disturbed in AMS individuals by high-altitude exposure. The reduction of IL10 after exposure to high altitude was associated with AMS.