Placental galectin-3 is reduced in early-onset preeclampsia

Preeclampsia pathogenesis and prediction - where are we now: the focus on the role of galectins and miRNAs

Preeclampsia is a complex, progressive multisystem hypertensive disorder during pregnancy that significantly contributes to increased maternal and perinatal morbidity and mortality. Two screening algorithms are in clinical use for detecting preeclampsia: first-trimester screening, which has been developed and validated for predicting early-onset preeclampsia but is less effective for late-onset disease; and the sFlt-1:PlGF biomarker ratio (soluble tyrosine kinase and placental growth factor) used in suspected cases of preeclampsia. This ratio has a high negative predictive value, allowing for the reliable exclusion of the disease. Both of these screening tests have not met expectations. This review attempts to summarize the current knowledge on the pathogenesis and prediction of preeclampsia and to draw attention to novel biomarkers with a focus on microRNAs and galectins. Although these molecules belong to two distinct biological classes, they functionally converge in regulating placental and immune pathways. Ample evidence supports their involvement in the molecular mechanisms underlying preeclampsia. Based on current knowledge, galectin-13, C19MC members, and miRNA-210 are associated with the trophoblast/placenta and conditions of placental ischemia or hypoxia. Their levels differ significantly in pregnant women at risk of preeclampsia as early as the late first and early second trimester, making them potential markers for predicting preeclampsia.

An assessment of organophosphate ester mixtures and the placental transcriptome

Prenatal exposure to organophosphate ester (OPE) chemicals, commonly used as flame retardants and plasticizers, has been associated with adverse birth outcomes. The placenta is a critical fetal organ and therefore may be involved in pathogenesis of birth outcomes. The goal of this study was to evaluate associations of 10 maternal urinary OPE metabolites, individually and as a mixture, with the placental transcriptome at birth in the Conditions Affecting Neurocognitive Development and Learning in Early Childhood (CANDLE) study. Individual OPE metabolites were evaluated for associations with individual genes as well as co-expressed gene modules. Mixtures analysis was conducted using quantile g-computation. The analyses were performed with the entire data set (N = 737) as well as the sex-stratified subsets. Two genes (HAP1 and RAP1GAP) were associated with bis(1,3-dichloro-2-propyl) phosphate (BDCPP), and six genes were associated the mixture in the full data set. 3 genes were associated with diphenyl phosphate (DPHP) and 36 genes were associated with the mixture in a male stratified analysis. 2 genes were associated with DPHP, and 1 gene was associated with diethyl phosphate (DEP) in a female stratified analysis. Three gene modules were associated with BDCPP or diphenyl phosphate (DPHP) and one module was associated with the OPE mixture. 12 WGCNA modules were associated with individual OPE metabolites or the mixture in males, and 1 WGCNA module was associated with DEP in females. Five of the OPE-associated gene modules were enriched for a total of 17 KEGG pathways, and 11 modules were enriched with targets of 12 nuclear hormone receptor transcription factors. Overall, novel associations were identified between the placental transcriptome and OPE metabolites, individually and in mixture, including differences based on fetal sex. These findings highlight the need for additional research on mechanisms of OPE-associated gene expression changes in the placenta and associated health outcomes.

Immune Cells and Infectious Diseases in Preeclampsia Susceptibility

Preeclampsia is a severe pregnancy disorder, affecting approximately 10% of pregnancies worldwide, characterised by hypertension and proteinuria after the 20th week of gestation. The condition poses significant risks to both maternal and fetal health, including cardiovascular complications and impaired fetal development. Recent trends indicate a rising incidence of preeclampsia, correlating with factors such as advanced maternal age and cardiovascular comorbidities. Emerging evidence also highlights a notable increase in the association between autoimmune and infectious diseases with preeclampsia. Autoimmune conditions, such as type 1 diabetes and systemic lupus erythematosus, and infections triggered by global health challenges, including leptospirosis, Zika, toxoplasmosis, and Chagas disease, are now recognised as significant contributors to preeclampsia susceptibility by affecting placental formation and function. This review focuses on the immunologic mechanisms underpinning preeclampsia, exploring how immune system dysregulation and infectious triggers exacerbate the condition. It also discusses the pathologic mechanisms, including galectins, that preeclampsia shares with autoimmune and infectious diseases, and their significant risk for adverse pregnancy outcomes. We emphasise the necessity for accurate diagnosis and vigilant monitoring of immune and infectious diseases during pregnancy to optimise management and reduce risks. By raising awareness about these evolving risks and their impact on pregnancy, we aim to enhance diagnostic practices and preventive strategies, ultimately improving outcomes for pregnant women, especially in regions affected by environmental changes and endemic diseases.

In vitro and in vivo effects of Galectin-3 inhibitor TD139 on inflammation and ERK/JNK/p38 pathway in gestational diabetes mellitus

This study aims to investigate the effects of the Galectin-3 (Gal-3) inhibitor TD139 on inflammation and the extracellular signal-regulated kinase (ERK)/c-Jun N-terminal kinase (JNK)/p38 pathway in gestational diabetes mellitus (GDM). Human placental tissues were treated with TD139 and TNF-α, assessing Gal-3, ERK/JNK/p38 activation, and inflammatory cytokines. GDM was induced in mice via subcutaneous injections of streptozotocin (STZ). After confirming GDM, mice were treated with 15 mg/kg TD139 on GD 10.5 12.5, 14.5, 16.5, and 18.5. Serum inflammatory cytokines were measured on GD 20.5, and post-delivery placental tissues were analyzed. Data were analyzed using one-way or two-way repeated measures ANOVA with post hoc tests. TD139 suppressed TNF-α-induced increases in Gal-3, IL-1β, IL-6, MCP-1, and ERK/JNK/p38 activation in placental tissues. In STZ-induced GDM mice, TD139 reduced glucose levels, weight loss, and food and water intake. TD139 significantly lowered TNF-α, IL-1β, IL-6, and MCP-1 in serum and placental tissues and inhibited the ERK/JNK/p38 pathway. TD139 improved pup numbers in GDM mice compared to untreated ones. TD139 reduces inflammation and inhibits the ERK/JNK/p38 pathway in TNF-α stimulated placental tissues and STZ-induced GDM mice, suggesting its therapeutic potential for managing GDM-related placental inflammation and improving pregnancy outcomes. The study used TNF-α to mimic GDM in placental tissues and an STZ-induced GDM mouse model, which may not fully represent human GDM complexity. Future research should explore alternative models, and broader signaling pathways, and thoroughly evaluate TD139's safety in pregnancy.

Bridging the Gap between Galectin-3 Expression and Hypertensive Pregnancy Disorders: A Narrative Review

Galectin-3 belongs to a family of soluble glycan-binding proteins, which are increasingly recognized as modulators of pregnancy-associated processes, including proper placental development. Gestational hypertension and preeclampsia are significant complications of pregnancy, affecting millions of women annually. Despite their prevalence, the underlying pathophysiological mechanisms remain poorly understood. Several theories have been proposed, including inflammation, placental insufficiency, disturbed placental invasion, and angiogenesis. The Scopus and PubMed/MEDLINE databases were utilized until the end of May 2024. In total, 11 articles with 1011 patients, with 558 in the control group and 453 in the preeclampsia group, were included. Seven articles investigated the expression of galectin-3 (Gal-3) in placental tissue samples, eight studies calculated the serum levels of Gal-3 in maternal blood samples, while one study referred to the possible correlation of galectin-3 levels in umbilical cord blood. The results were inconsistent in both the placental tissue and maternal serum; Gal-3 placental expression was found to be statistically increased in five studies compared to that in women without gestational hypertensive disorders, while two studies either mentioned decreased expression or no difference. Similarly, the Gal-3 maternal serum levels, compared to those in women without gestational hypertensive disorders, were found to be statistically increased in five studies, while three studies did not find any statistical difference. Gal-3 can play a crucial role in the pathogenesis of preeclampsia, and its expression is influenced by gestational age and placental insufficiency. A further investigation ought to be conducted to enlighten the correlation of Gal-3 with gestational hypertension and preeclampsia development.

Placental glycosylation senses the anti-angiogenic milieu induced by human sFLT1 during pregnancy

Abnormal placental angiogenesis during gestation resulting from high levels of anti-angiogenic factors, soluble fms-like tyrosine kinase-1 (sFLT1) and soluble endoglin, has been implicated in the progression of preeclampsia (PE). This heterogeneous syndrome (defined by hypertension with or without proteinuria after 20 weeks of pregnancy) remains a major global health burden with long-term consequences for both mothers and child. Previously, we showed that in vivo systemic human (hsFLT1) overexpression led to reduced placental efficiency and PE-like syndrome in mice. Galectins (gal-1, -3 and -9) are critical determinants of vascular adaptation to pregnancy and dysregulation of the galectin-glycan circuits is associated with the development of this life-threatening disease. In this study, we assessed the galectin-glycan networks at the maternal-fetal interface associated with the hsFLT1-induced PE in mice. We observed an increase on the maternal gal-1 expression in the decidua and junctional zone layers of the placenta derived from hs FLT1high pregnancies. In contrast, placental gal-3 and gal-9 expression were not sensitive to the hsFLT1 overexpression. In addition, O- and N-linked glycan expression, poly-LacNAc sequences and terminal sialylation were down-regulated in hsFLT1 high placentas. Thus, the gal-1-glycan axis appear to play an important role counteracting the anti-angiogenic status caused by sFLT1, becoming critical for vascular adaptation at the maternal-fetal interface.

Genetic Associations of Circulating Cardiovascular Proteins With Gestational Hypertension and Preeclampsia

Importance

Hypertensive disorders of pregnancy (HDPs), including gestational hypertension and preeclampsia, are important contributors to maternal morbidity and mortality worldwide. In addition, women with HDPs face an elevated long-term risk of cardiovascular disease.

Objective

To identify proteins in the circulation associated with HDPs.

Design, Setting, and Participants

Two-sample mendelian randomization (MR) tested the associations of genetic instruments for cardiovascular disease-related proteins with gestational hypertension and preeclampsia. In downstream analyses, a systematic review of observational data was conducted to evaluate the identified proteins' dynamics across gestation in hypertensive vs normotensive pregnancies, and phenome-wide MR analyses were performed to identify potential non-HDP-related effects associated with the prioritized proteins. Genetic association data for cardiovascular disease-related proteins were obtained from the Systematic and Combined Analysis of Olink Proteins (SCALLOP) consortium. Genetic association data for the HDPs were obtained from recent European-ancestry genome-wide association study meta-analyses for gestational hypertension and preeclampsia. Study data were analyzed October 2022 to October 2023.

Exposures

Genetic instruments for 90 candidate proteins implicated in cardiovascular diseases, constructed using cis-protein quantitative trait loci (cis-pQTLs).

Main Outcomes and Measures

Gestational hypertension and preeclampsia.

Results

Genetic association data for cardiovascular disease-related proteins were obtained from 21 758 participants from the SCALLOP consortium. Genetic association data for the HDPs were obtained from 393 238 female individuals (8636 cases and 384 602 controls) for gestational hypertension and 606 903 female individuals (16 032 cases and 590 871 controls) for preeclampsia. Seventy-five of 90 proteins (83.3%) had at least 1 valid cis-pQTL. Of those, 10 proteins (13.3%) were significantly associated with HDPs. Four were robust to sensitivity analyses for gestational hypertension (cluster of differentiation 40, eosinophil cationic protein [ECP], galectin 3, N-terminal pro-brain natriuretic peptide [NT-proBNP]), and 2 were robust for preeclampsia (cystatin B, heat shock protein 27 [HSP27]). Consistent with the MR findings, observational data revealed that lower NT-proBNP (0.76- to 0.88-fold difference vs no HDPs) and higher HSP27 (2.40-fold difference vs no HDPs) levels during the first trimester of pregnancy were associated with increased risk of HDPs, as were higher levels of ECP (1.60-fold difference vs no HDPs). Phenome-wide MR analyses identified 37 unique non-HDP-related protein-disease associations, suggesting potential on-target effects associated with interventions lowering HDP risk through the identified proteins.

Conclusions and Relevance

Study findings suggest genetic associations of 4 cardiovascular disease-related proteins with gestational hypertension and 2 associated with preeclampsia. Future studies are required to test the efficacy of targeting the corresponding pathways to reduce HDP risk.

Intronic variants of LGALS13 gene encoding placental protein (PP13) are linked with increased risk of infection-associated spontaneous preterm birth

PROBLEM

Spontaneous preterm birth (sPTB) is a global health issue. Studies suggest infection and infection-based inflammatory responses are major risk factors for sPTB. Considering the important role of anti-inflammatory proteins in pregnancy, the study aimed to find the association between anti-inflammatory LGALS13 gene variants IVS2-22 A/G (rs2233706) and IVS3+72 T/A (rs2233708) and the risk of sPTB during Chlamydia trachomatis, Mycoplasma hominis and Ureaplasma urealyticum infection in Indian population.

METHOD OF STUDY

Placental samples of 160 sPTB and 160 term women were collected. Pathogens were detected by PCR. The genotyping of LGALS13 gene variants IVS2-22 A/G (rs2233706) and IVS3+72 T/A (rs2233708) was done by qualitative real-time PCR using allelic discrimination method (VIC- and FAM-labeled).

RESULTS

The frequency of AG or GG genotype of LGALS13 IVS2-22A/G polymorphism (rs2233706) was 75.5% in infected sPTB cases and 14.4% in uninfected sPTB cases and 7.3% in term birth controls (p < .0001), while the frequency of TA or AA genotype of LGALS13 IVS3+72T/A polymorphism (rs2233708) was 83.6% in infected sPTB cases and 18% in uninfected sPTB cases and 12.7% in term birth controls (p < .0001). The genotypic frequencies for both the variants of LGALS13 were statistically significant (p < .0001) in the infected sPTB versus uninfected sPTB and term birth controls.

CONCLUSIONS

Study reveals strong association between the presence of immunological gene variants LGALS13 IVS2-22 A/G (rs2233706) and LGALS13 IVS3+72 T/A (rs2233708) and risk of sPTB during C. trachomatis, M. hominis and U. urealyticum infection.