Placental Protein Research Articles

Chemical crosslinking and peptide mapping reveal structural characteristics of interdomain 1 and 2 of the placental malaria adherent protein VAR2CSA

The sequestration of Plasmodium falciparum in the placenta contributes to multiple placental malaria pathologies. VAR2CSA, a member of P. falciparum erythrocyte membrane protein 1 family of variant proteins, mediates the sequestration via the binding of parasite‐infected red blood cells to chondroitin 4‐sulfate in the placenta. This selective binding makes VAR2CSA a specific target for developing placental malaria treatment strategies. VAR2CSA contains ~310‐kDa C4S‐binding ectodomain, which thought to consist of an N‐terminal segment (NTS), six canonical Duffy‐binding‐like domains (DBL1‐DBL6), and interdomain (ID1 and ID2) segments. The ectodomain contains 116 cysteine residues. Up to eight intradomain disulfide bonds may be observed in canonical DBL domains; however, not all cysteine residues in a DBL domain conform to this pattern and additional ones are located outside the DBL domains. Recent cryo‐electron microscopy reconstructions revealed the functional core structure containing a third interdomain component (ID3) and substantiated the carbohydrate‐binding channel identified earlier. However, up to 46 % of the core, including the paths of ID1, regions of ID2 remain untraced in these structures. Here, by chemical cross‐linking/mass spectrometry of VAR2CSA, we identify additional interdomain interactions in the unmodeled regions of VAR2CSA. Disulfide bond mapping identifies roles for non‐canonical disulfide bonds and reveals previously un‐modelled interdomain disulfide bonds that link ID2 to DBL4ε. In addition, we resolve a disagreement in the interpretation of ID3 by unambiguously identifying the cysteine residues involved in the disulfide bond between DBL4ε and ID3.

Gq Signaling in the Placental Syncytiotrophoblast Layer During Preeclampsia

Preeclampsia is a pregnancy‐associated cardiovascular disorder characterized by hypertension and proteinuria after 20 weeks of gestation. Generalized cellular ‘stress’ (oxidative, mitochondrial, etc.) within the syncytiotrophoblast (STB) layer of placenta is theorized to drive its pathogenesis. Hormones implicated in preeclampsia such as angiotensin, endothelin, and vasopressin signal via receptors that typically couple to the Gq second‐messenger cascade, and Regulator of G protein Signaling‐2 (RGS2) buffers this signaling. We have published that RGS2 expression is decreased in human preeclamptic placenta, and reducing RGS2 expression in placenta is sufficient to cause development of key features of this disorder in mice. Unpublished in situ hybridization data indicate that in both humans and mice, RGS2 is present in the STB layer – and that RGS2 expression in the STB layer is reduced during preeclampsia in humans. Collectively, these findings lead us to generally hypothesize that excess Gq signaling specifically within the STB layer, whether due to excessive hormonal activation or loss of RGS2‐mediated buffering, causes STB‐Stress and thereby contributes to the pathogenesis of preeclampsia. Therefore, the objective of this study was to test whether artificial, exogenous activation of Gq signaling only within STB cells is sufficient to induce placental and maternal phenotypes of preeclampsia in mice.CAG‐FLEX‐hM3Dq+/+ (Gαq DREADD, Jax 026943) or C57BL/6J dams were bred with Gcm1‐Cre+/‐ sires (Jax 026625) or non‐transgenic littermates to elicit STB‐restricted hM3Dqexpression in ≍50% or 0% of placentas. The synthetic DREADD ligand clozapine N‐oxide (CNO) or saline vehicle was administered (2 mg/kg/d, ip) mid‐gestation (GD 12.5‐14.5). Placental and maternal phenotypes were compared between Cre– and Cre+ placentas within a dam, CNO‐ vs saline‐injected double‐transgenic dams, and double‐ vs single/non‐transgenic dams treated with CNO. Activation of Gq in the STB layer caused maternal proteinuria (n=4‐9, 49±6 mg/day vs 28±4 mg/day; p=0.01). Labyrinth vascularization, assessed by percentage of CD31+ area, was reduced with Gq activation (n=5, Cre+ 21±1%, Cre– 27±2%; p=0.01), while other regions remained unaffected (Decidua: Cre+ 14±4%, Cre– 14±3%; Junctional Zone: Cre+ 11±4%, Cre– 12±3%). Possible reductions in placental mass (n=5 Cre+ 0.12±0.01g, Cre– 0.15±0.01g; p=0.06), and placental vascular endothelial growth factor protein levels (n=6‐7 117±67 ng/g vs 151±12 ng/g; p=0.06) were noted, but no obvious trend in fetal growth restriction was observed (n=5 Cre+ 0.21±0.06g, Cre– 0.29±0.04g). These data support the pathological significance of excess Gq signaling specifically within the STB layer. Ongoing studies are aimed at further characterizing maternal phenotypes (blood pressure, circulating factors) in these models, and the synergistic effects of simultaneous STB‐specific deletion of RGS2 upon sensitivity to Gq stimulation in this cell type.

Decreased Placental mTOR Signaling And Increased Placental Apoptosis Are Associated With Secondhand Smoke (SHS)‐Induced Intrauterine Growth Restriction (IUGR) In Mice

Intrauterine growth restriction (IUGR) is a disease affecting 10% of all pregnancies. IUGR is associated with maternal, fetal, and placental abnormalities, but studies investigating the inducibility of IUGR by secondhand smoke (SHS) are limited. The mTOR pathway regulates protein expression and cell growth. Disrupted mTOR signaling and apoptosis are associated with the development of several obstetric complications including IUGR. We tested the hypothesis that SHS exposure disrupts the mTOR pathway and apoptosis in mice. C57Bl6 mice were exposed to SHS for 4 days from day 14 to day 17 of gestation (dGA). At the time of necropsy (18 dGA) placental and fetal weights were recorded and tissues were immediately frozen for immunoblot analysis. Mice exposed to SHS demonstrated a significant reduction in fetal weight (7.35‐fold; p≤0.0001) and placental weight (1.13‐fold; p≤0.0001) compared to controls. Significant decreases were observed for placental activation of mTOR (2.1‐fold; p<0.03), p70 (1.9‐fold; p,0.03) and 4EBP1 (1.3‐fold (p<0.03) in IUGR placentas compared to controls. Increased placental active caspase 3 (1.1‐fold; p<0.04) and the antiapoptotic placental XIAP protein (2.2‐fold; p<0.03) were also detected during SHS treatment compared to controls. We conclude that decreased mTOR pathway is associated with lessened fetal and placental size during SHS induced IUGR. This decrease was associated with increased caspase 3 and that elevated XIAP protein may signify an attempted protective mechanism that counters increased apoptosis observed in the SHS‐induced IUGR placenta. These studies provide insight into tobacco‐mediated IUGR development and clarify avenues that may be helpful in the alleviation of placental complications.

Human placental proteomics and exon variant studies link AAT/SERPINA1 with spontaneous preterm birth

BackgroundPreterm birth is defined as live birth before 37 completed weeks of pregnancy, and it is a major problem worldwide. The molecular mechanisms that lead to onset of spontaneous preterm birth are incompletely understood. Prediction and evaluation of the risk of preterm birth is challenging as there is a lack of accurate biomarkers. In this study, our aim was to identify placental proteins that associate with spontaneous preterm birth.MethodsWe analyzed the proteomes from placentas to identify proteins that associate with both gestational age and spontaneous labor. Next, rare and potentially damaging gene variants of the identified protein candidates were sought for from our whole exome sequencing data. Further experiments we performed on placental samples and placenta-associated cells to explore the location and function of the spontaneous preterm labor-associated proteins in placentas.ResultsExome sequencing data revealed rare damaging variants in SERPINA1 in families with recurrent spontaneous preterm deliveries. Protein and mRNA levels of alpha-1 antitrypsin/SERPINA1 from the maternal side of the placenta were downregulated in spontaneous preterm births. Alpha-1 antitrypsin was expressed by villous trophoblasts in the placenta, and immunoelectron microscopy showed localization in decidual fibrinoid deposits in association with specific extracellular proteins. siRNA knockdown in trophoblast-derived HTR8/SVneo cells revealed that SERPINA1 had a marked effect on regulation of the actin cytoskeleton pathway, Slit–Robo signaling, and extracellular matrix organization.ConclusionsAlpha-1 antitrypsin is a protease inhibitor. We propose that loss of the protease inhibition effects of alpha-1 antitrypsin renders structures critical to maintaining pregnancy susceptible to proteases and inflammatory activation. This may lead to spontaneous premature birth.

Placental protein levels in maternal serum are associated with adverse pregnancy outcomes in nulliparous patients

The Eunice Kennedy Shriver National Institute of Child Health and Human Development Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be was established to investigate the underlying causes and pathophysiological pathways associated with adverse pregnancy outcomes in nulliparous gravidas. This study aimed to study placental physiology and identify novel biomarkers concerning adverse pregnancy outcomes, including preterm birth (medically indicated and spontaneous), preeclampsia, small-for-gestational-age neonates, and stillbirth. We measured levels of placental proteins in the maternal circulation in the first 2 trimesters of pregnancy. Maternal serum samples were collected at 2 study visits (6-13 weeks and 16-21 weeks), and levels of 9 analytes were measured. The analytes we measured were vascular endothelial growth factor, placental growth factor, endoglin, soluble fms-like tyrosine kinase-1, A disintegrin and metalloproteinase domain-containing protein 12, pregnancy-associated plasma protein A, free beta-human chorionic gonadotropin, inhibin A, and alpha-fetoprotein. The primary outcome was preterm birth between 20 0/7 and 36 6/7 weeks of gestation. The secondary outcomes were spontaneous preterm births, medically indicated preterm births, preeclampsia, small-for-gestational-age neonates, and stillbirth. A total of 10,038 eligible gravidas were enrolled in the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be cohort, from which a nested case-control study was performed comparing 800 cases with preterm birth (466 spontaneous preterm births, 330 medically indicated preterm births, and 4 unclassified preterm births), 568 with preeclampsia, 406 with small-for-gestational-age birth, and 49 with stillbirth with 911 controls who delivered at term without complications. Although levels of each analyte generally differed between cases and controls at 1 or 2 visits, the odds ratios revealed a <2-fold difference between cases and controls in all comparisons. Receiver operating characteristic curves, generated to determine the relationship between analyte levels and preterm birth and the other adverse pregnancy outcomes, resulted in areas under the receiver operating characteristic curves that were relatively low (range, 0.50-0.64) for each analyte. Logistic regression modeling demonstrated that areas under the receiver operating characteristic curves for predicting adverse pregnancy outcomes were greater using baseline clinical characteristics and combinations of analytes than baseline characteristics alone, but areas under the receiver operating characteristic curves remained relatively low for each outcome (range, 0.65-0.78). We have found significant associations between maternal serum levels of analytes evaluated early in pregnancy and subsequent adverse pregnancy outcomes in nulliparous gravidas. However, the test characteristics for these analytes do not support their use as clinical biomarkers to predict adverse pregnancy outcomes, either alone or in combination with maternal clinical characteristics.

Predictive performance of first trimester serum galectin-13/PP-13 in preeclampsia screening: A systematic review and meta-analysis.

Placental protein-13 (PP-13) is a member of the galectin group involved in placental implantation, maternal artery remodeling, and placental inflammatory processes. Its levels are lower in the first trimester for pregnancies later affected by ischemic placental disease, and slowly increase during the second and third trimesters of pregnancy. The aim of the present meta-analysis is to assess the predictive performance of PP-13 in first trimester preeclampsia screening. PubMed, Web of Science, Scopus, Embase, BIOSIS, and Cochrane databases were used to find relevant studies. All prospective and retrospective observational studies that evaluated the accuracy of PP-13 in predicting preeclampsia were assessed. The investigation revealed that the quantitative synthesis was based on 14 studies with a total number of 8,239 women. The pooled sensitivity of PP-13 for the prediction of preeclampsia was 0.53 [95% (confidence interval (CI), 0.08-0.99], and the pooled specificity was 0.83 (95% CI, 0.38-1.29). Further analysis revealed a higher accuracy of PP-13 for the screening of late-onset preeclampsia [pooled sensitivity of 0.58 [95% CI, -0.17-1.33) with a specificity of 0.85 (95% CI, 0.10-1.60)] when compared with early-onset preeclampsia [pooled sensitivity of 0.51 (95% CI, -0.04-1.05) with a specificity of 0.88 (95% CI, 0.33-1.42)]. In conclusion, PP-13 appears to be a promising biomarker for evaluating the risk of developing preeclampsia during the first trimester of pregnancy. As a result, incorporating it into future predictive models is a viable option.

Low-dose aspirin prevents LPS-induced preeclampsia-like phenotype via AQP-1 and the MAPK/ERK 1/2 pathway.

Clinical studies suggest that early pregnancy is the critical window for the prevention of preeclampsia by low-dose aspirin (LDA). Abnormal extravillous trophoblast (EVT) cell invasion and spiral artery remodeling during early placentation have been observed in preeclampsia cases. Thus, we hypothesized LDA prevents preeclampsia by mitigating EVT migration/invasion and spiral artery remodeling dysfunction. A single systemic lipopolysaccharide (LPS) (1μg/kg) injection was administrated in pregnant mice at e14.5 to induce a preeclampsia-like pregnant mouse model. We administered LDA (2.5μg/g body weight/day) and observed the effects on LPS-induced preeclampsia-like symptoms by examining the placental histology, protein expression, EVT invasion, and spiral artery remodeling. In human EVT cell line, HTR-8/SVneo, we investigated cell invasion and migration by matrigel and wound healing assays, respectively. Signaling pathways were surveyed using inhibitors, siRNA transfections, and Western blot. LDA treatment significantly reversed the preeclampsia-like phenotype induced by LPS, as observed by decreases in hypertension, proteinuria, and fetal growth retardation. The numbers of pathological lesions, including excessive extracellular matrix deposition, endotheliosis, and collapsed glomerular capillaries in kidneys, were significantly lower in the LDA+LPS vs. the LPS group. LDA pretreatment eliminated placental lesions, including calcification, edema, and narrowed uterine spiral arteries and reduced aquaporin-1 (AQP-1) protein expression. In HTR-8/SVneo cells, LDA rescued the decreased cell migration and invasion induced by LPS. The phosphorylation of ERK1/2 was up-regulated and AQP-1 expression was decreased by LPS, which were reversed by LDA treatments. The effects of LDA were inhibited when AQP-1 expression was downregulated by siRNA transfection. This study provides new evidence that supports the use of LDA for the prevention of preeclampsia and suggests that the effects of LDA are mediated through a novel mechanism of a water channel, AQP-1, and MAPK/ERK 1/2 signaling.

Placental Nutrient Transporters and Maternal Fatty Acids in SGA, AGA, and LGA Newborns From Mothers With and Without Obesity.

Adverse environmental factors in early life result in fetal metabolic programming and increased risk of adult diseases. Birth weight is an indirect marker of the intrauterine environment, modulated by nutrient availability and placental transport capacity. However, studies of placental transporters in idiopathic birth weight alterations and in maternal obesity in relation to neonatal metabolic outcomes are scarce. We aimed to analyze the placental nutrient transporter protein expression in small (SGA, n = 14), adequate (AGA, n = 18), and large (LGA n = 10) gestational age term for newborns from healthy or obese mothers (LGA-OB, n = 9) and their association with maternal fatty acids, metabolic status, placental triglycerides, and neonatal outcomes. The transporter expression was determined by Western blot. The fatty acid profile was evaluated by gas chromatography, and placental triglycerides were quantified by an enzymatic colorimetric method. GLUT1 was higher in LGA and lower in SGA and positively correlated with maternal HbA1c and placental weight (PW). SNAT2 was lower in SGA, while SNAT4 was lower in LGA-OB. FATP1 was lower in SGA and higher in LGA. SNAT4 correlated negatively and FATP1 correlated positively with the PW and birth anthropometry (BA). Placental triglycerides were higher in LGA and LGA-OB and correlated with pregestational BMI, maternal insulin, and BA. Maternal docosahexaenoic acid (DHA) was higher in SGA, specifically in male placentas, correlating negatively with maternal triglycerides, PW, cord glucose, and abdominal perimeter. Palmitic acid (PA) correlated positively with FATP4 and cord insulin, linoleic acid correlated negatively with PA and maternal cholesterol, and arachidonic acid correlated inversely with maternal TG and directly with FATP4. Our study highlights the importance of placental programming in birth weight both in healthy and obese pregnancies.

Maternal Diet Quality Is Associated with Placental Proteins in the Placental Insulin/Growth Factor, Environmental Stress, Inflammation, and mTOR Signaling Pathways: The Healthy Start ECHO Cohort

BackgroundMaternal nutritional status affects placental function, which may underlie the intrauterine origins of obesity and diabetes. The extent to which diet quality is associated with placental signaling and which specific pathways are impacted is unknown. ObjectivesTo examine sex-specific associations of maternal diet quality according to the Healthy Eating Index (HEI)—developed to align with recommendations from the Dietary Guidelines for Americans—with placental proteins involved in metabolism and mediators of environmental stress, inflammation, and growth factors. MethodsAmong 108 women from the Healthy Start cohort with a mean ± SD age of 29.0 ± 6.1 y and a prepregnancy BMI (in kg/m2) of 24.8 ± 5.3, we conducted multivariable linear regression analysis stratified by offspring sex. We adjusted for maternal race or ethnicity, age, education, prenatal smoking habits, and physical activity and tested for an association of maternal HEI >57 compared with ≤57 and the abundance and phosphorylation of key proteins involved in insulin/growth factor signaling; mediators of environmental stress, inflammation, and growth factors; mechanistic target of rapamycin signaling proteins; and energy sensing in placental villus samples. HEI >57 was chosen given its prior relevance among Healthy Start mother–child dyads. ResultsIn adjusted models, HEI >57 was associated with greater abundance of insulin receptor β (0.80; 95% CI: 0.11, 1.49) in placentas of females. In males, maternal HEI >57 was associated with greater activation and abundance of select placental nutrient-sensing proteins and environmental stress, inflammation, and growth factor proteins (S6K1Thr389/S6K1: 0.81; 95% CI: 0.21, 1.41; JNK1Thr183/Tyr185/JNK1: 0.82; 95% CI: 0.27, 1.37; JNK2Thr183/Tyr185/JNK2: 0.57; 95% CI: 0.02, 1.11). ConclusionsHigher-quality diet had sex-specific associations with placental protein abundance/phosphorylation. Given that these proteins have been correlated with neonatal anthropometry, our findings provide insight into modifiable factors and placental pathways that should be examined in future studies as potential links between maternal diet and offspring metabolic health. This trial was registered at http://www.clinicaltrials.gov clinicaltrials.gov as NCT02273297.

Dietary curcumin supplementation ameliorates placental inflammation in rats with intra-uterine growth retardation by inhibiting the NF-κB signaling pathway

Intra-uterine growth restriction (IUGR) is a serious, commonly occurring reproductive problem in humans. This study aimed to investigate the effects of daily curcumin supplementation during pregnancy on placental inflammation, in a rat model of IUGR. Pregnant rats were divided into three groups based on diet: (1) normal protein (19%) (NP), (2) low protein (8%) (LP), and (3) low protein + 100 mg curcumin/kg bw per day (LPC). The results showed that curcumin accumulation in the serum, placenta and liver. Fetal weight and placental total protein levels were increased in the LPC group compared with those in the LP group. Dietary curcumin supplementation normalized the low protein diet-induced decrease of placental weight, blood sinusoid area, and proliferating cell nuclear antigen (PCNA) protein expression levels. It also reversed the low protein diet-induced increase of serum triglyceride levels and tumor necrosis factor alpha-like (TNF-α), interleukin 1 beta (IL-1β), and interleukin 6 (IL-6) concentrations in both the placenta and serum. Additionally, it normalized the enhanced gene expression levels of the pro-inflammatory cytokines in the LP group to that in the NP group. Furthermore, it downregulated the inhibitor of kappa Balpha (IκBα) and nuclear factor kappa Balpha (NF-κB) phosphorylation. In conclusion, daily curcumin supplementation ameliorates placental inflammation in rats with IUGR by inhibiting the NF-κB signaling pathway.

Placental proteins with predicted roles in fetal development decrease in premature infants.

Emerging evidence from animal experiments indicate that factors secreted by the placenta are critical for normal fetal organ development. Our objective was to characterize the umbilical vein and artery proteome in preterm infants and identify proteins that decrease in the neonatal circulation following delivery. Cord blood at delivery and neonatal blood at 48-72 h of life was collected in 25 preterm infants. Plasma protein abundance was determined using the SomaLogic platform. When comparing protein levels of umbilical venous to arterial cord blood, 434 proteins were significantly higher indicating placental secretion into the fetal circulation. Moreover, when comparing neonatal blood to umbilical vein levels, 142 proteins were significantly lower. These proteins included Endoplasmic reticulum resident protein 29, CD59, Fibroblast growth factor 2 and Dynactin subunit 2, which are involved in brain development and prevention of brain damage as well as Fibroblast growth factor 1 which prevents lung fibrosis. The late second trimester human placenta secretes proteins into the fetal circulation which decrease following delivery. Many of these proteins are predicted to be important in the development of fetal organs. Further studies are needed to directly link placental proteins to organ development and poor outcomes in preterm infants. Prematurity remains a leading cause of morbidity and mortality requiring the development of novel treatments. Emerging evidence from animal studies suggest that factors secreted from the placenta may be critical in the development of the fetus. We report that the preterm human placenta secretes an array of proteins into the fetal circulation. Some of these proteins are predicted to be involved in the development of the brain and the lung. When born prematurely, infants are deprived of these placental proteins, which may contribute to their poor outcomes.

Placental sFlt-1 Gene Delivery in Early Primate Pregnancy Suppresses Uterine Spiral Artery Remodeling.

Uterine spiral artery remodeling (SAR) is essential for promoting placental perfusion and fetal development. A defect in SAR results in placental ischemia and increase in placental expression and serum levels of the soluble fms-like tyrosine kinase-1 (sFlt-1) receptor that binds to and suppresses vascular endothelial growth factor (VEGF) bioavailability, thereby leading to maternal vascular dysfunction. We have established a nonhuman primate model of impaired SAR and maternal vascular dysfunction by prematurely elevating estradiol levels in early baboon pregnancy. However, it is unknown whether this primate model of defective SAR involves an increase in placental expression of sFlt-1, which may suppress VEGF bioavailability and thus SAR in the first trimester. Therefore, to establish the role of sFlt-1 in early pregnancy, SAR was quantified in baboons treated on days 25 through 59 of gestation (term = 184 days) with estradiol or with the sFlt-1 gene targeted selectively to the placental basal plate by ultrasound-mediated/microbubble-facilitated gene delivery technology. Placental basal plate sFlt-1 protein expression was 2-fold higher (P < 0.038) and the level of SAR for vessels > 25 µm in diameter was 72% and 63% lower (P < 0.01), respectively, in estradiol-treated and sFlt-1 gene-treated baboons than in untreated animals. In summary, prematurely elevating estradiol levels or sFlt-1 gene delivery increased placental basal plate sFlt-1 protein expression and suppressed SAR in early baboon pregnancy. This study makes the novel discovery that in elevated levels sFlt-1 has a role both in suppressing SAR in early primate pregnancy and maternal vascular endothelial function in late gestation.

Acute Severe Acute Respiratory Syndrome Coronavirus 2 Infection in Pregnancy Is Associated with Placental Angiotensin-Converting Enzyme 2 Shedding

While the human placenta may be infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the rate of fetal transmission is low, suggesting a barrier at the maternal-fetal interface. Angiotensin-converting enzyme (ACE)2, the main receptor for SARS-CoV-2, is regulated by a metalloprotease cleavage enzyme, a disintegrin and metalloprotease domain 17 (ADAM17). ACE2 is expressed in the human placenta, but its regulation in relation to maternal SARS-CoV-2 infection in pregnancy is not well understood. This study evaluated ACE2 expression, ADAM17 activity, and serum ACE2 abundance in a cohort of matched villous placental and maternal serum samples from control pregnancies (SARS-CoV-2 negative, n = 8) and pregnancies affected by symptomatic maternal SARS-CoV-2 infections in the second trimester [2nd Tri coronavirus disease (COVID), n = 8] and third trimester (3rd Tri COVID, n = 8). In 3rd Tri COVID compared with control and 2nd Tri COVID villous placental tissues, ACE2 mRNA expression was remarkably elevated; however, ACE2 protein expression was significantly decreased with a parallel increase in ADAM17 activity. Soluble ACE2 was also significantly increased in the maternal serum from 3rd Tri COVID infections compared with control and 2nd Tri COVID pregnancies. These data suggest that in acute maternal SARS-CoV-2 infections, decreased placental ACE2 protein may be the result of ACE2 shedding and highlights the importance of ACE2 for studies on SARS-CoV-2 responses at the maternal-fetal interface.

Effects of maternal iron deficiency anemia on placenta and cord blood iron status with specific reference to the iron transport protein ferroportin 1

Introduction: Iron deficiency anemia is the most prevalent nutritional deficiency disorder in pregnant women. During pregnancy, nutrients, including iron, are transferred from the mother to the fetus through the placenta, in which the placental transport protein Ferroportin1 (FPN1) plays a crucial role. It has been frequently observed that developing fetus is immune to anemia despite the presence of anemia in the mother, the mechanisms underlying which have not been identified. We, therefore, planned the present study to explore the effect of maternal iron deficiency anemia on the expression of FPN1 in the placenta. Material and Methods: Two hundred pregnant women recruited were divided into anemic and nonanemic groups based on their predelivery hemoglobin levels (<11 g/dl and ≥11 g/dl, respectively). After delivery, placental expression of FPN1 was studied by immunohistochemistry and mRNA analysis, and neonatal anthropometry was performed. Results: Of the 200 women, 59% were anemic. FPN1 protein immunohistochemical staining in placenta showed a statistically significant increase with increasing severity of anemia. Similarly, placental mRNA expression levels of the FPN1 gene were observed to be higher in anemic mothers when compared with nonanemic mothers. Discussion and Conclusion: Thus, our study for the first time shows that maternal iron deficiency increases placental FPN1 protein and mRNA expression, thereby probably facilitating increased transport of iron from the mother to the fetus.

The role of placental proteins in pregnant women during preparation for childbirth

<h3>ЦЕЛЬ ИССЛЕДОВАНИЯ</h3> Определение роли плацентарных белков — трофобластического бета-1-гликопротеина (ТБГ), гликоделина и плацентарного альфа-1-микроглобулина (ПАМГ) в процессе «созревания» шейки матки перед своевременными родами. <h3>МАТЕРИАЛ И МЕТОДЫ</h3> Обследованы 245 беременных в сроки беременности 38—39 нед, в том числе 65 со «зрелой» шейкой матки (1-я группа), 84 с «недостаточно зрелой» шейкой матки (2-я группа) и 96 пациенток с «незрелой» шейкой матки (3-я группа). Беременные 2-й и 3-й групп обследовались дважды в течение одной недели. Материалом для исследования служила периферическая венозная кровь, в сыворотке которой определяли концентрацию ТБГ методом двойной иммунодиффузии с использованием стандартной тест-системы, содержание ПАМГ и гликоделина — методом иммуноферментного анализа. <h3>РЕЗУЛЬТАТЫ</h3> У первородящих женщин с «незрелой» шейкой матки при доношенной беременности отмечается повышенный уровень ТБГ при неизмененных уровнях ПАМГ и гликоделина в периферической крови. В отсутствие динамики подготовки организма к родам повышенное содержание ТБГ в крови матери сохраняется, повышается концентрация гликоделина, уровень ПАМГ не меняется; при «созревании» шейки матки уровень ТБГ снижается. <h3>ЗАКЛЮЧЕНИЕ</h3> Можно предпожить, что ТБГ принимает участие в патогенезе ремоделирования шейки матки, роль гликоделина и ПАМГ не определена. Снижение уровня ТБГ у женщин с доношенной беременностью можно использовать в качестве критерия эффективности подготовки организма к родам.

Influence of Placental Metalloproteinase-9 Protein on the Branching Architecture of Chorionic Blood Vessels of Human Placenta

Introduction: In human placenta, two different branching patterns of chorionic blood vessels exist. In the dispersal type, the chorionic blood vessels undergo successive divisions with gradually diminishing caliber as the blood vessels traverse towards the placental margins. In the magistral type, the blood vessels traverse without appreciable decrease in diameter. We hypothesize, that matrix-degrading enzymes secreted by cytotrophoblasts may influence the branching patterns of these chorionic blood vessels. We, therefore, determined if placental expression of matrix metalloproteinase-9 (MMP-9) protein differed between the two vascular patterns of chorionic blood vessels of human placenta. Methods: 26 full-term delivered placentas were collected from normotensive women. Chorionic villi (CV) were isolated. CV MMP-9 protein was analyzed using human MMP-9 monoclonal antibody based ELISA kits. A novel method was used to determine the vascular patterns of the placentas from placental photographs. Independent t test was used for statistical analysis. P&lt; 0.05 was considered significant. Results: The branching pattern of the chorionic blood vessels was 54% dispersal and 46% of the magistral types. In placentas with dispersal type of branching pattern, MMP-9 protein expression was significantly higher (p=0.035). Women who delivered placentas with magistral type of branching pattern, the mean newborn weight was found to be significantly higher (p=0.039). Conclusion: The study introduces a novel method to investigate chorionic vascular network of human placenta. Our findings underscore the importance of CV MMP-9 protein in affecting the placental branching architecture of chorionic blood vessels in humans. In the magistral type, the calibers of the chorionic blood vessels from the point of insertion of the umbilical cord to the placental margins remained more or less unchanged. We suggest, that this unchanged caliber of blood vessels in the magistral type, may have allowed better nourishment and oxygen to be catered to the fetus; resulting in fetal weight gain.

Impaired Compensatory Vasodilatory Effect Mediated by Wolfram Syndrome 1 and Corticotropin-Releasing Hormone Family Peptides in 17α-Ethynylestradiol-Induced Intrahepatic Cholestasis Pregnant Rats When Under Additional Acute Hypoxia Stress

Abstract Objective: To investigate the possible regulatory mechanism of corticotropin-releasing hormone (CRH), urocortin (UCN), and Wolfram syndrome 1 (WFS1) in 17α-ethynylestradiol (EE)-induced intrahepatic cholestasis pregnant rats and its ischemia reperfusion (IR) model. Methods: Pregnant rats (n = 60) were randomly divided into four experimental groups by random number table (Control, EE, IR, and EE-IR groups), and were studied on the 17th, 19th, and 21st gestational days (GD) (n = 5 in each group at the indicated time). Growth and development indicators of fetal rats among these four groups were recorded. Enzyme-linked immunosorbent assay was employed to detect CRH, UCN, and WFS1 levels in maternal sera. Western blotting and real-time polymerase chain reaction were used to quantify placental protein and placental mRNA levels of CRH, UCN, and WFS1. Multivariate analysis of variance and least significant difference test were used to establish the group and individual comparisons. Results: A significant difference was found in placenta weight (F = 8.10, P &lt; 0.05), fetal rat weight (F = 40.86, P &lt; 0.05), fetal rat length (F = 61.61, P &lt; 0.05), and fetal rat tail length (F = 55.63, P &lt; 0.05) among four groups on the 17th ,19th , and 21st GD.What's more, the overall differences of maternal serum UCN levels among Control, EE, IR, and EE-IR groups were significant (F = 2.48, P &lt; 0.05). Expression of WFS1 mRNA in the EE-IR group was significantly increased and higher than Control (0.46 ± 0.15 vs. 0.24 ± 0.09, P &lt; 0.05), EE (0.46 ± 0.15 vs. 0.17 ± 0.04, P &gt; 0.05), and IR (0.46 ± 0.15 vs. 0.22 ± 0.15, P &gt; 0.05) groups at 19th GD, indicating that endoplasmic reticulum stress may be activated. However, the expression of CRH (0.42 ± 0.05 vs. 0.58 ± 0.12, P &lt; 0.05), UCN (0.43 ± 0.01 vs. 0.47 ± 0.16, P &gt; 0.05), and WFS1 (0.57 ± 0.07 vs. 0.74 ± 0.12, P &gt; 0.05) protein in the EE-IR group was subsided compared to the IR group at 17th GD. Conclusion: Fetal rat growth restriction was found in the EE-induced intrahepatic cholestasis model. This study revealed that significant changes in the maternal sera level of UCN , placental level of WFS1 mRNA and placental levels of CRH, UCN, and WFS1 protein in chronic versus acute stress in a rat model of pregnancy. This suggests an impaired compensatory vasodilatory effect mediated by these factors at gene transcription and protein translation levels, following acute hypoxia stress in EE-induced intrahepatic cholestasis in pregnant rats.

Placental mRNA and Protein Expression of VDR, CYP27B1 and CYP2R1 Genes Related to Vitamin D Metabolism in Preeclamptic Women

(1) Background: Considerable evidence indicates that the occurrence of preeclampsia (PE) is associated with a reduced vitamin D (VD) level. Several studies have found that VD deficiency is correlated with disturbed trophoblast invasion, reduced angiogenesis and increased vasoconstriction. Because the vitamin D receptor (VDR) and CYP27B1 and CYP2R1 hydrolases are strongly involved in VD metabolism, the goal of the present study was to evaluate their genes and proteins expression in the placentas from preeclamptic women. (2) Methods: Samples and clinical data were obtained from 100 Polish women (41 women with preeclampsia and 59 healthy pregnant controls). The whole PE group was divided into subgroups according to gestation week of pregnancy ending before and after 34 gestational weeks (early/late-onset preeclampsia (EOPE/LOPE)). However, finally, to reduce confounding by differences in gestational age, the EOPE group was excluded from the analysis of mRNA and protein placental expression, and we focus on the comparison between LOPE and control groups. The placental VDR, CYP27B1 and CYP2R1 mRNA expression was analyzed using RT-PCR, and placental protein levels were determined by ELISA assay. (3) Results. (3.1) Placental gene expression: Expression levels of both genes, CYP27B1 (1.17 vs. 1.05 in controls, p = 0.006) and CYP2R1 (2.01 vs. 1.89 in controls, p = 0.039), were significantly higher in preeclamptic placentas than in the control group. Interestingly, VDR expression was significantly lower in placentas from the PE group (1.15 vs. 1.20 in controls, p = 0.030). After dividing all preeclamptic women into subgroups only for the CYP27B1 gene, a significantly higher placental expression in the LOPE subgroup than the healthy controls was observed (padj = 0.038). (3.2) Placental protein expression: The results revealed that protein expression levels of CYP27B1 in the preeclamptic group were similar (5.32 vs. 5.23 in controls, p = 0.530). There was a significant difference in median VDR and CYP2R1 protein levels between studied groups (VDR: 2.56 vs. 3.32 in controls, p &lt; 0.001; CYP2R1: 1.32 vs. 1.43 in controls, p = 0.019). After stratification of preeclamptic women into subgroups, a significant difference was observed only in the VDR protein level. The medians in the LOPE subgroups were significantly lower compared to the healthy control group. In the whole study group, the placental VDR protein level was inversely correlated with systolic and diastolic blood pressure (all p &lt; 0.001), and positively correlated with gestational age (p &lt; 0.001) and infant birth weight (p = 0.014). (4) Conclusions: Lower mRNA and protein expression of VDR in preeclamptic placentas, and also VDR protein expression, could play a pivotal role in preeclampsia development. Additionally, the higher mRNA expression of both CYP27B1 and CYP2R1 hydrolase genes in placentas from preeclamptic women could indicate the compensatory role of these enzymes in preeclampsia etiology. Our results also indicate that placental VDR protein level could be one of the factors modulating blood pressure in pregnant women, as well as influencing gestational age and infant birth weight. Considering the importance of these findings, future studies are warranted.

Elevated expression of galectin-3, thioredoxin and thioredoxin interacting protein in preeclampsia.

Preeclampsia (PE) is a pregnancy-related syndrome characterized by the onset of hypertension and proteinuria that can lead to end-organ dysfunction. Galectin-3 (Gal-3) is involved in cell growth, differentiation, inflammation and fibrosis. Thioredoxin (TXN) acts as antioxidant enzyme in several cellular processes, regulating inflammation and inhibiting apoptosis. TXNIP is an endogenous inhibitor of TXN. We evaluated changes in the inflammatory response of Gal-3, TXN, and TXNIP at the level of maternal blood, placenta, and umbilical cord blood of women with PE. Ten women with PE and 20 with normal pregnancy (NP) were recruited during admission for delivery. Blood samples were obtained from parturients and umbilical cords, and placental tissue for analysis. Gal-3 and TXNIP mRNA expression were higher in maternal plasma in PE group compared to NP and were lower in cord blood plasma and placentas in the PE group. In the PE group, TXN/TXNIP mRNA ratio was higher in cord blood plasma (2.07) compared to maternal plasma (1.09). TXN/TXNIP placental protein ratio was similar between PE (0.89) and NP (0.79). ELISA demonstrated that Gal-3 levels in maternal serum were significantly higher in the PE vs. the NP group. Pro-inflammatory changes were expressed by high Gal-3 and TXNIP mRNA in maternal blood of PE women, but not in their placental and cord blood samples. These findings may imply that the placenta has a role in protecting the fetus from the damages of inflammatory response, which is more common in PE than in NP.

Circulating heat shock protein 27 (HSPB1) levels in prediction of pre-eclampsia: A pilot study.

To determine whether circulating heat shock proteins HSP27/HSPB1 and HSP90α/HSPC1may be useful for early prediction of the occurrence of pre-eclampsia in asymptomatic women. We have measured by ELISA the levels of HSPB1, HSPC1, and placental protein 13 (PP13) in serum samples from 44 women in the first trimester (10-12weeks) and second trimester (17-20weeks) of pregnancy. Western blot and immunohistochemistry for HSPB1 and HSPC1 were performed. HSPB1serum levels were higher in women with pre-eclampsia than in normotensive pregnant women at the first and second trimester (P=0.003), whereas PP13levels decreased in women with pre-eclampsia only in the first trimester of gestation (P=0.021). We also observed higher HSPB1levels in patients with early-onset pre-eclampsia in the first and second trimester (P=0.014). This pilot study points out that circulating HSPB1levels in first and second trimester might be useful for predicting the occurrence of pre-eclampsia in asymptomatic women. Further validation studies are needed to finally establish this protein as a candidate predictive biomarker of pre-eclampsia.