Placental protein 13: An important biological protein in preeclampsia

Biomarkers for Early Prediction and Management of Preeclampsia: A Comprehensive Review

Preeclampsia is a common complication of pregnancy. It is a multi-organ disorder that remains one of the main causes of maternal morbidity and mortality. Additionally, preeclampsia leads to many complications that can occur in the fetus or newborn. Preeclampsia occurs in about 1 in 20 pregnant women. This review focuses on the prediction of preeclampsia in women, using various biomarkers, in particular, a factor combining the use of soluble FMS-like tyrosinokinase-1 (sFlt-1) and placental growth factor (PlGF). A low value of the sFlt-1/PlGF ratio rules out the occurrence of preeclampsia within 4 weeks of the test result, and its high value predicts the occurrence of preeclampsia within even 1 week. The review also highlights other factors, such as pregnancy-associated plasma protein A, placental protein 13, disintegrin and metalloprotease 12, ß-human chorionic gonadotropin, inhibin-A, soluble endoglin, nitric oxide, and growth differentiation factor 15. Biomarker testing offers reliable and cost-effective screening methods for early detection, prognosis, and monitoring of preeclampsia. Early diagnosis in groups of women at high risk for preeclampsia allows for quick intervention, preventing the undesirable effects of preeclampsia. However, further research is needed to validate and optimize the use of biomarkers for more accurate prediction and diagnosis. This article aims to review the role of biomarkers, including the sFlt1/PlGF ratio, in the prognosis and management of preeclampsia.

Extracellular vesicles alter trophoblast function in pregnancies complicated by COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and resulting coronavirus disease (COVID-19) causes placental dysfunction, which increases the risk of adverse pregnancy outcomes. While abnormal placental pathology resulting from COVID-19 is common, direct infection of the placenta is rare. This suggests that pathophysiology associated with maternal COVID-19, rather than direct placental infection, is responsible for placental dysfunction and alteration of the placental transcriptome. We hypothesized that maternal circulating extracellular vesicles (EVs), altered by COVID-19 during pregnancy, contribute to placental dysfunction. To examine this hypothesis, we characterized maternal circulating EVs from pregnancies complicated by COVID-19 and tested their effects on trophoblast cell physiology in vitro . We found that the gestational timing of COVID-19 is a major determinant of circulating EV function and cargo. In vitro trophoblast exposure to EVs isolated from patients with an active infection at the time of delivery, but not EVs isolated from Controls, altered key trophoblast functions including hormone production and invasion. Thus, circulating EVs from participants with an active infection, both symptomatic and asymptomatic cases, can disrupt vital trophoblast functions. EV cargo differed between participants with COVID-19 and Controls, which may contribute to the disruption of the placental transcriptome and morphology. Our findings show that COVID-19 can have effects throughout pregnancy on circulating EVs and circulating EVs are likely to participate in placental dysfunction induced by COVID-19.

Evaluation of maternal serum SERPINC1, E-selectin, P-selectin, RBP4 and PP13 levels in pregnancies complicated with preeclampsia

OBJECTIVE

The aim of this study is to investigate whether Serpin clade C (SERPINC1), E-selectin, P-selectin, Placental protein 13 (PP13), and Retinol-binding protein-4 (RBP4) levels in maternal serum were associated with the presence of preeclampsia and to compare them with uncomplicated pregnancies.

METHODS

This prospective study included 40 women with preeclampsia and 40 healthy pregnant women. An enzyme-linked immunosorbent assay kit was used to measure serum SERPINC1, E-selectin, P-selectin, PP13, and RBP4 levels.

RESULTS

The preeclampsia group had significantly higher E-selectin and P-selectin levels than the control group. PP13 and SERPINC1 levels were also significantly lower than the control group. There was no significant difference in RBP4 levels. The receiver operating characteristic curve revealed the best cutoff values for the following: E-selectin >19.2 ng/mL, with 87.5% sensitivity and 95% specificity; P-selectin >5.1 ng/mL, with 97.5% sensitivity and 100% specificity; PP13 ≤ 107.03 pg/mL, with 72.5% sensitivity and 77.5% specificity; and SERPINC1 ≤ 87.76 ng/mL, with 100% sensitivity and 97.5% specificity.

CONCLUSION

In this study, the endothelial dysfunction parameters SERPINC1, PP13, E-selectin, and P-selectin were found to be associated with preeclampsia. Endothelial dysfunction biomarkers in maternal non-serum body fluids may differ. More research is needed, especially to determine the relationship between SERPINC1 and preeclampsia.

From Biomarkers to the Molecular Mechanism of Preeclampsia-A Comprehensive Literature Review

Preeclampsia (PE) is a prevalent obstetric illness affecting pregnant women worldwide. This comprehensive literature review aims to examine the role of biomarkers and understand the molecular mechanisms underlying PE. The review encompasses studies on biomarkers for predicting, diagnosing, and monitoring PE, focusing on their molecular mechanisms in maternal blood or urine samples. Past research has advanced our understanding of PE pathogenesis, but the etiology remains unclear. Biomarkers such as PlGF, sFlt-1, PP-13, and PAPP-A have shown promise in risk classification and preventive measures, although challenges exist, including low detection rates and discrepancies in predicting different PE subtypes. Future perspectives highlight the importance of larger prospective studies to explore predictive biomarkers and their molecular mechanisms, improving screening efficacy and distinguishing between early-onset and late-onset PE. Biomarker assessments offer reliable and cost-effective screening methods for early detection, prognosis, and monitoring of PE. Early identification of high-risk women enables timely intervention, preventing adverse outcomes. Further research is needed to validate and optimize biomarker models for accurate prediction and diagnosis, ultimately improving maternal and fetal health outcomes.

Prediction Model for Pre-Eclampsia Using Gestational-Age-Specific Serum Creatinine Distribution

Pre-eclampsia (PE) is a pregnancy-related disease, causing significant threats to both mothers and babies. Numerous studies have identified the association between PE and renal dysfunction. However, in clinical practice, kidney problems in pregnant women are often overlooked due to physiologic adaptations during pregnancy, including renal hyperfiltration. Recent studies have reported serum creatinine (SCr) level distribution based on gestational age (GA) and demonstrated that deviations from the expected patterns can predict adverse pregnancy outcomes, including PE. This study aimed to establish a PE prediction model using expert knowledge and by considering renal physiologic adaptation during pregnancy. This retrospective study included pregnant women who delivered at the Wonju Severance Christian Hospital. Input variables, such as age, gestational weeks, chronic diseases, and SCr levels, were used to establish the PE prediction model. By integrating SCr, GA, GA-specific SCr distribution, and quartile groups of GA-specific SCr (GAQ) were made. To provide generalized performance, a random sampling method was used. As a result, GAQ improved the predictive performance for any cases of PE and triple cases, including PE, preterm birth, and fetal growth restriction. We propose a prediction model for PE consolidating readily available clinical blood test information and pregnancy-related renal physiologic adaptations.

Circulating biomarkers associated with placental dysfunction and their utility for predicting fetal growth restriction

Fetal growth restriction (FGR) leading to low birth weight (LBW) is a major cause of neonatal morbidity and mortality worldwide. Normal placental development involves a series of highly regulated processes involving a multitude of hormones, transcription factors, and cell lineages. Failure to achieve this leads to placental dysfunction and related placental diseases such as pre-clampsia and FGR. Early recognition of at-risk pregnancies is important because careful maternal and fetal surveillance can potentially prevent adverse maternal and perinatal outcomes by judicious pregnancy surveillance and careful timing of birth. Given the association between a variety of circulating maternal biomarkers, adverse pregnancy, and perinatal outcomes, screening tests based on these biomarkers, incorporating maternal characteristics, fetal biophysical or circulatory variables have been developed. However, their clinical utility has yet to be proven. Of the current biomarkers, placental growth factor and soluble fms-like tyrosine kinase 1 appear to have the most promise for placental dysfunction and predictive utility for FGR.

First‐trimester plasma extracellular heat shock proteins levels and risk of preeclampsia

Preeclampsia (PE) occurs annually in 8% of pregnancies. Patients without risk factors represent 10% of these. There are currently no first-trimester biochemical markers that accurately predict PE. An increase in serum 60- and 70-KDa extracellular heat shock proteins (eHsp) has been shown in patients who developed PE at 34 weeks. We sought to determine whether there is a relationship between first-trimester eHsp and the development of PE. This was a prospective cohort study performed at a third level hospital in Mexico City from 2019 to 2020. eHsp levels were measured during the first-trimester ultrasound in singleton pregnancies with no comorbidities. First-trimester eHsp levels and biochemical parameters of organ dysfunction were compared between patients who developed preeclampsia and those who did not. All statistical analyses and model of correlation (r) between eHsp and clinical parameter were performed using bootstrapping R-software. p-values <0.05 were considered significant. The final analysis included 41 patients. PE occurred in 11 cases. eHsp-60 and eHsp-70 were significantly higher at 12 weeks in patients who developed PE (p = 0.001), while eHsp-27 was significantly lower (p = 0.004). Significant differences in first-trimester eHsp concentration suggest that these are possible early biomarkers useful for the prediction of PE.

PLACENTAL BIOMARKERS: PP13, VEGF IN DIAGNOSTICS OF EARLY AND LATE PREECLAMPSIA

OBJECTIVE

The aim: To investigate role of CD23, VEGF and PP13 in diagnostics of early and late preeclampsia, and their benefit for prediction of preeclampsia.

PATIENTS AND METHODS

Materials and methods: Investigation included 40 placentas from deliveries in women with preeclampsia (main group) and 40 placentas from physiological delivery in somatically healthy women, who had no complications during pregnancy (control group). Placentas in the main group were devided into two sub-groups (20 in each) - with early and late preeclampsia. Each group underwent both hystomorphometrical and immunohystochemical investigation with biomarkers CD23, VEGF and PP13.

RESULTS

Results: Positive immunohystochemical reaction to PP13 was determined in all samples of syncitiotrophoblast of villi of chorion. Investigations showed that expression of PP13 in sub-groups with early and late preeclampsia was a lot lower comparing to control group (normal pregnancies). Positive immunohystochemical reaction to VEGF was determined in all samples of endothelia of the capillaries of the villi of chorion. Our investigation showed that expression of VEGF in sub-groups with early and late PE was a lot lower comparing to a control group. Immunohystochemical reaction to CD23 was comperatively lower in all samples in endothelia of the capillariesof the villi of chorion and cyncithiotrophoblast.

CONCLUSION

Conclusions: Determined specialties of the expression of angiogenic factors ( PlGF, VEGF, endoglin) and production of PP13, by altered expression of VEGF, PlGF in first trimester of pregnancy, which is associated with lowest production of PP13, accompanied by placental dysfunction and preeclampsia.

The Role and Application of Exosomes and Their Cargos in Reproductive Diseases: A Systematic Review

In recent years, the incidence of the reproductive diseases is increasing year-by-year, leading to abortion or fetal arrest, which seriously affects the reproductive health of human beings and the reproductive efficiency of animals. Exosomes are phospholipid bilayer vesicles that are widely distributed in living organisms and released by the cells of various organs and tissues. Exosomes contain proteins, RNA, lipids, and other components and are important carriers of information transfer between cells, which play a variety of physiological and pathological regulatory functions. More and more studies have found that exosomes and their connotations play an important role in the diagnosis, prognosis and treatment of diseases. A systematic review was conducted in this manuscript and then highlights our knowledge about the diagnostic and therapeutic applications of exosomes to reproductive diseases, such as polycystic ovary syndrome (PCOS), endometriosis, premature ovarian failure (POF), preeclampsia, polycystic, endometrial cancer, cervical cancer, ovarian cancer, and prostate gland cancer.

An observational study of pro- and anti-angiogenic factors in hypertensive disorders of pregnancy in women of African ancestry

Hypertensive disorders in pregnancy (HDPs) are the leading cause of maternal and perinatal deaths worldwide. Despite the widely reported multisystemic pathophysiology of pre-eclampsia and other HDPs, it is unknown whether these disorders represent a continuum or separate entities making clinical diagnosis a challenge. This study aimed to investigate angiogenic, metabolic and immunoregulatory specific profiles of hypertensive and gestationally matched normotensive pregnancies. A total of 200 pregnancies from a regional hospital in South Africa, via convenience sampling, were quantitatively analysed for circulating sFlt-1; PlGF; VEGF; sENG; PAPP-A; PP13; ADAMTS 12; TGF-β1 in maternal serum samples using ELISA technique. Serum protein markers TGF-β1, sENG and PAPP-A were significantly increased (p < .05) in early-onset pre-eclampsia vs. NG1 groups. sFlt-1 was significantly higher in late-onset pre-eclampsia vs NG2 groups. The GH group showed a significant increase in TGF-β1 and PAPP-A vs. NG1 counterpart. ADAMTS12 and sENG were significantly lower in gestational hypertension vs. early-onset pre-eclampsia. No significant differences were seen in PlGF, VEGF and PP13 levels across the groups. These changes show the HDP spectrum has distinct characteristics on the angiogenic profile. Based on these results, further validation of diagnostic and prognostic biomarkers of pre-eclampsia and gestational hypertension is warranted.Impact statementWhat is already known on this subject? Hypertensive pregnancy disorders are a public health problem with adverse effects on both mother and neonate. The elusive pathogenesis of this syndrome combined with the late prevalence of symptoms leaves clinicians with a myriad of theories and indefinite treatments. The investigation into conventional anti-/angiogenic factors has been extensively studied in pre-eclampsia patients only. The overlapping clinical presentation of pre-eclampsia and gestational hypertension further complicates the diagnosis of disorders.What do the results of this study add? The investigation of novel angiogenic, metabolic and inflammatory markers will firstly contribute to generating a database for researchers both nationally and internationally. This combinatory triad of markers will assist in elucidating and differentiating between early- and late-onset preeclampsia versus gestational hypertension. The results of our cohort study suggest possible early diagnostic markers for pre-eclampsia and gestational hypertension.What are the implications of these findings for clinical practice and/or further research? Research in this area will contribute to an improvement in early disease management which will ultimately lead to a reduction in health care costs and mortality rate locally and globally. It will also enforce diagnostic and prognostic markers for hypertensive pregnancy diseases and warrant further investigation into the proteins primarily involved in the trophoblastic invasion. This will then clarify whether these two closely related hypertensive disorders represent a continuum or two separate entities.

Cadmium inhibits forskolin-induced differentiation of human placental BeWo cells

Cadmium (Cd) is an environmental pollutant. Blood Cd levels in pregnant women have been associated with premature births, infant birth size, placenta previa, and placenta accreta. There have been concerns on the reproductive developmental toxicity of Cd. The choriocarcinoma cell line BeWo, a cellular in vitro model for studying syncytial fusion, has been widely used to study the reproductive and developmental toxic effects of pollutants. Here, we examine the inhibitory effect of Cd against forskolin (FSK)-induced BeWo differentiation. Results showed that Cd exposure inhibited the FSK-induced expression of syncytiotrophoblast-related genes LGALS13, ERVFRD1, SDC1, and CGB3. Inhibition of LGALS13 expression was due to the inhibition of the PKA pathway, whereas the inhibition of the other three genes could be due to the inhibition of the other pathways. These findings could help clarify the reproductive and developmental toxicity of Cd.

The expression profile of plasmatic exosomal lncRNAs in early-onset preeclampsia by sequencing

Identification of the expression profile of exosomal lncRNAs in plasma from PE patients to provide new insights into the molecular mechanism. Five pregnant patients with early-onset severe PE were included in the PE group and 5 normal pregnant patients were included in the control group in the training cohort. Differential expression of genes were identified between the two groups, and were verified in plasma exosomes from 12 additional pregnant patients with EPE and 12 normal pregnant patients. KEGG pathway analysis and GO enrichment analysis were performed using online prediction databases to construct a lncRNA-miRNA-mRNA co-expression network. From there a panel of candidate lncRNAs was selected and validated via quantitative PCR in the two groups. In the 289 differential lncRNA, 155 were up-regulated and 134 were down-regulated. Bioinformatics enrichment analysis demonstrated that the target genes of differential expression of lncRNAs were enriched in 159 pathways with P < 0.05, including cancer, metabolic and PI3K-Akt signaling pathways. Three lncRNAs exhibited significant differential expressed in exosomes between the two groups. A lncRNA-miRNA-mRNA co-expression network analysis showed that ENST00000559730-hsa-miR-661-NUDT16 was the most frequently associated with susceptibility-relation of PE. The significant differences of plasmatic exosomal lncRNA expression between normal pregnant women and early-onset severe PE patients suggest that lncRNA may participate in the pathogenetic process of PE. Our study provides a preliminary bioinformatic foundation in order to find PE markers in plasma which further increase the sample size, and continue to verify the function of lncRNA in vitro.

Primary Human Trophoblasts Mimic the Preeclampsia Phenotype after Acute Hypoxia-Reoxygenation Insult

Preeclampsia (PE) is a pregnancy-specific disorder that affects 3 to 5% of pregnancies worldwide and is one of the leading causes of maternal and fetal morbidity and mortality. Nevertheless, how these events occur remains unclear. We hypothesized that the induction of hypoxic conditions in vitro in primary human trophoblast cells would mimic several characteristics of PE found in vivo. We applied and characterized a model of primary cytotrophoblasts isolated from healthy pregnancies that were placed under different oxygen concentrations: ambient O₂ (5% pCO₂, 21%pO₂, 24 h, termed “normoxia”), low O₂ concentration (5% pCO₂, 1.5% pO₂, 24 h, termed “hypoxia”), or “hypoxia/reoxygenation” (H/R: 6 h intervals of normoxia and hypoxia for 24 h). Various established preeclamptic markers were assessed in this cell model and compared to placental tissues obtained from PE pregnancies. Seventeen PE markers were analyzed by qPCR, and the protein secretion of soluble fms-like tyrosine kinase 1 (sFlT-1) and the placenta growth factor (PlGF) was determined by ELISA. Thirteen of seventeen genes associated with angiogenesis, the renin–angiotensin system, oxidative stress, endoplasmic reticulum stress, and the inflammasome complex were susceptible to H/R and hypoxia, mimicking the expression pattern of PE tissue. In cell culture supernatants, the secretion of sFlT-1 was increased in hypoxia, while PlGF release was significantly reduced in H/R and hypoxia. In the supernatants of our cell models, the sFlT-1/PlGF ratio in hypoxia and H/R was higher than 38, which is a strong indicator for PE in clinical practice. These results suggest that our cellular models reflect important pathological processes occurring in PE and are therefore suitable as PE in vitro models.

Predictive Performance of Placental Protein 13 for Screening Preeclampsia in the First Trimester: A Systematic Review and Meta-Analysis

Preeclampsia is a pregnancy-specific syndrome that affects maternal and neonatal mortality. Several serum biomarkers can be used to predict preeclampsia. Among these proteins, placental protein 13 (PP13) has received progressively more interest in recent studies. The decrease in PP13 expression is one of the earliest signs for the development of preeclampsia and has shown its predictive performance for preeclampsia. In this meta-analysis, we collected 17 observational studies with 40,474 pregnant women. The overall sensitivity of PP13 to predict preeclampsia was 0.62 [95% confidence interval (CI) = 0.49–0.74], the specificity was 0.84 (95%CI = 0.81–0.86), and the diagnostic odds ratio was nine (95%CI = 5–15). The area under the curve for summary receiver operating characteristic was 0.84. We then chose the early-onset preeclampsia as a subgroup. The sensitivity of early-onset subgroup was 0.63 (95%CI = 0.58–0.76), the specificity was 0.85 (95%CI = 0.82–0.88), and the diagnostic odds ratio was 10 (95%CI = 6–18). The findings of our meta-analysis indicate that PP13 may be an effective serum biomarker for the predictive screening of preeclampsia. Nonetheless, large prospective cohort studies and randomized controlled trials are expected to uncover its application in clinical practice. The heterogeneity of the original trials may limit the clinical application of PP13.

Systematic Review Registration:https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=188948 The meta-analysis was registered in PROSPERO (CRD42020188948).

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

OBJECTIVE

To determine whether circulating heat shock proteins HSP27/HSPB1 and HSP90α/HSPC1 may be useful for early prediction of the occurrence of pre-eclampsia in asymptomatic women.

METHODS

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 (10-12 weeks) and second trimester (17-20 weeks) of pregnancy. Western blot and immunohistochemistry for HSPB1 and HSPC1 were performed.

RESULTS

HSPB1 serum levels were higher in women with pre-eclampsia than in normotensive pregnant women at the first and second trimester (P = 0.003), whereas PP13 levels decreased in women with pre-eclampsia only in the first trimester of gestation (P = 0.021). We also observed higher HSPB1 levels in patients with early-onset pre-eclampsia in the first and second trimester (P = 0.014).

CONCLUSION

This pilot study points out that circulating HSPB1 levels 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.

Role of Extracellular Vesicles in Placental Inflammation and Local Immune Balance

Background

Pregnancy maintenance depends on the formation of normal placentas accompanied by trophoblast invasion and vascular remodeling. Various types of cells, such as trophoblasts, endothelial cells, immune cells, mesenchymal stem cells (MSCs), and adipocytes, mediate cell-to-cell interactions through soluble factors to maintain normal placental development. Extracellular vesicles (EVs) are diverse nanosized to microsized membrane-bound particles released from various cells. EVs contain tens to thousands of different RNA, proteins, small molecules, DNA fragments, and bioactive lipids. EV-derived microRNAs (miRNAs) and proteins regulate inflammation and trophoblast invasion in the placental microenvironment. Maternal-fetal communication through EV can regulate the key signaling pathways involved in pregnancy maintenance, from implantation to immune regulation. Therefore, EVs and the encapsulating factors play important roles in pregnancy, some of which might be potential biomarkers.

Conclusion

In this review, we have summarized published studies about the EVs in the placentation and pregnancy-related diseases. By summarizing the role of EVs and their delivering active molecules in pregnancy-related diseases, it provides novel insight into the diagnosis and treatment of diseases.

Advances in biomarker development and potential application for preeclampsia based on pathogenesis

Preeclampsia (PE) is a pregnancy-specific complication that seriously threatens the health and safety of mothers and infants. The etiology of PE has not been fully elucidated, and no effective treatments are currently available. A pregnant woman with PE often has to make a tough choice on either endangering her own health to give a birth or being forced to terminate her pregnancy. It is recommended by the International Federation of Gynecology and Obstetrics that the combination of maternal high-risk factors and biomarkers could form a good strategy for predicting the risk of PE. Such a combination may also enable more effective monitoring and early clinical intervention in high-risk populations to reduce the risk of PE. Therefore, biomarkers validated by extensive clinical research may be formally applied for clinical PE risk prediction. In this review, we summarized data from clinical research on potential biomarkers and classified them according to the current four major hypotheses, namely placental or trophoblast ischemia and hypoxia, vascular endothelial injury, oxidative stress, and immune dysregulation. Additionally, we also discussed the underlying mechanisms by which these potential biomarkers may be involved in the pathogenesis of PE. Finally, we propose that multiple biomarkers reflecting different aspects of the disease pathogenesis should be used in combination to detect the high-risk PE population in support of clinically targeted intervention and prevention of PE. It is expected that tests made of more sensitive and reliable PE biomarkers based on the aforementioned major hypotheses could potentially improve the accuracy of PE prediction in the future.

association between urinary placental protein 13 and soluble fms-like tyrosine kinase-1 in preeclamptic women in the third trimester of pregnancy

Background: Preeclampsia (PE) is diagnosed after 20 weeks of gestation. This multisystem disorder affects 2-7% of pregnant women. PE is a serious complication of pregnancy and one of the main causes of maternal and neonatal mortality and morbidity in the world. The inadequate placentation process results in a change in anti-angiogenic factors levels, such as placental protein 13 (PP13) and soluble fms-like tyrosine kinase 1 (sFlt-1). Objectives: To investigate the correlation between urinary PP13 and sFlt-1 in preeclamptic women in their third trimester of pregnancy. Methods: A case-control study was carried out from August 2018 till January 2019. Urine samples were collected from pregnant women at Al-Elweyia Hospital, Al-Hakeem Hospital, and Al- Imamain Al-Kadhimain Medical City (in Baghdad, Iraq). The patients’ group include fifty women with PE in the third trimester (25 mild and 25 severe). Fifty healthy pregnant women (at their third trimester of pregnancy) were studied as a control group. Results: The mean urinary PP13 levels were decreased in women with PE significantly (p≤ 0.05) (mild and severe) compared with healthy women (43.44±4.914 pg/ml, 33.34±1.863 pg/ml, and 51.84 ±2.60 pg/ml) respectively. Also, urinary sFlt-1 concentrations were decreased non-significantly (p> 0.05) in women with PE (mild and severe) compared with healthy women (5.71±0.414 ng/ml, 5.31±0.38 ng/ml and 6.01±0.282 ng/ml), respectively. Conclusions: Urinary PP13 and sFlt-1 levels in the third trimester of pregnancy were significantly correlated with the severity of PE, and urinary levels of PP13 were found to be decreased significantly in patients with PE than in healthy pregnant women in the 3rd trimester of pregnancy.

Galectin-13/placental protein 13: redox-active disulfides as switches for regulating structure, function and cellular distribution

Galectin-13 (Gal-13) plays numerous roles in regulating the relationship between maternal and fetal tissues. Low expression levels or mutations of the lectin can result in pre-eclampsia. The previous crystal structure and gel filtration data show that Gal-13 dimerizes via formation of two disulfide bonds formed by Cys136 and Cys138. In the present study, we mutated them to serine (C136S, C138S and C136S/C138S), crystalized the variants and solved their crystal structures. All variants crystallized as monomers. In the C136S structure, Cys138 formed a disulfide bond with Cys19, indicating that Cys19 is important for regulation of reversible disulfide bond formation in this lectin. Hemagglutination assays demonstrated that all variants are inactive at inducing erythrocyte agglutination, even though gel filtration profiles indicate that C136S and C138S could still form dimers, suggesting that these dimers do not exhibit the same activity as wild-type (WT) Gal-13. In HeLa cells, the three variants were found to be distributed the same as with WT Gal-13. However, a Gal-13 variant (delT221) truncated at T221 could not be transported into the nucleus, possibly explaining why women having this variant get pre-eclampsia. Considering the normally high concentration of glutathione in cells, WT Gal-13 should exist mostly as a monomer in cytoplasm, consistent with the monomeric variant C136S/C138S, which has a similar ability to interact with HOXA1 as WT Gal-13.

Therapeutic Prospects in Preeclampsia - A Mini-Review

BACKGROUND

Preeclapmsia (PE) is characterized by early onset symptoms such as elevated blood pressure, proteinuria and edema in the pregnant woman, and may result in seizures in the affected female. Currently, there are no therapeutic drugs available to treat this condition, but there are interventions to regulate the symptoms based on the gestational period of the fetus, although the largely favored option is delivery of the fetus and placenta.

OBJECTIVE

A search for biomolecules associated with PE was conducted so as to identify diagnostic markers and therapeutic leads.

RESULTS

The literature search resulted in the identification of biomolecules such as Corin and Placental Protein 13 (PP13), among others that are associated with PE. Thereby, giving an insight into the various mechanistic pathways involved in the causation of PE. However, it is also evident that PE cannot be solely attributed to any single mechanism but is due to an interplay of different factors that have led to the development of this disease condition.

CONCLUSION

The identified biomarkers would ultimately help in understanding this complex disease and perhaps lead to the discovery of potential effective molecular targets for clinical trials, thereby providing a valuable therapeutic option for affected pregnant women.