Endocan expression is increased in the placenta from obese women with gestational diabetes mellitus

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.

Roles of endothelial cell specific molecule‑1 in tumor angiogenesis (Review)

Angiogenesis plays a crucial role in tumor growth and metastasis, and is heavily influenced by the tumor microenvironment (TME). Endothelial cell dysfunction is a key factor in tumor angiogenesis and is characterized by the aberrant expression of pro-angiogenic factors. Endothelial cell specific molecule-1 (ESM1), also known as endocan, is a marker of endothelial cell dysfunction. Although ESM1 is primarily expressed in normal endothelial cells, dysregulated ESM1 expression has been observed in human tumors and animal tumor models, and implicated in tumor growth, metastasis and angiogenesis. The precise role of ESM1 in tumor angiogenesis and its potential regulatory mechanisms are not yet conclusively defined. However, the aim of the present review was to explore the involvement of ESM1 in the process of tumor angiogenesis in the TME and the characteristics of neovascularization. In addition, the present review discusses the interaction between ESM1 and angiogenic factors, as well as the mechanisms through which ESM1 contributes to tumor angiogenesis. Furthermore, the reciprocal regulation between ESM1 and the TME is explored. Finally, the potential of targeting ESM1 as a therapeutic strategy for tumor angiogenesis is presented.

Investigation of maternal serum endocan concentrations in pregnant women with gestational diabetes mellitus; a prospective case-control study

OBJECTIVE

We aimed to investigate the maternal serum endocan concentrations in pregnant women diagnosed with Gestational Diabetes Mellitus (GDM) and to investigate the usability of serum endocan in GDM screening.

METHODS

This prospective case-control study was conducted with 160 pregnant women. The GDM group consisted of 80 pregnant women who had 75 g OGTT between the 24th and 28th weeks of pregnancy and were diagnosed with GDM. The control group consisted of 80 healthy pregnant women who were matched with the GDM group in terms of age and body mass index (BMI) and had a normal 75 g OGTT result. Serum endocan concentrations were evaluated between 24 and 28 weeks of gestation in all participants and the groups were compared in terms of serum endocan concentrations.

RESULTS

The median maternal serum endocan concentration was found to be significantly higher in the GDM group than in the control group (498 ng/L, and 467 ng/L, respectively, p = 0.024). In the subgroup analysis according to the BMI of the participants, the highest median maternal serum endocan concentration (513 ng/L) was found in the overweight GDM group. ROC analysis was performed to determine the value of maternal serum endocan concentration in predicting GDM. AUC analysis of maternal serum endocan for estimation of GDM was 0.603 (p = 0.024, 95% CI = 0.515 - 0.691). The optimal threshold value for maternal serum endocan concentration was determined as 376 ng/L with 88.75% sensitivity and 32.5% specificity.

CONCLUSION

Although serum endocan does not have high enough specificity to be used as an alternative to OGTT in GDM screening between 24 and 28 weeks of gestation, we think that it is somehow involved in the pathogenesis of GDM. The contribution of placental endocan expression to the serum concentration and the effect of blood glucose regulation on serum endocan concentration in GDM remain to be investigated.

Is maternal serum endocan level a novel marker in gestational diabetes mellitus?

AIM

To determine whether there was a significant difference between serum endocan levels of pregnant women with and without gestational diabetes mellitus (GDM).

METHODS

A total of 90 pregnant women, 45 with gestational diabetes and 45 healthy pregnant women, between 24 and 28 gestational weeks, were included in this prospective case-control study. The pregnant women were screened for gestational diabetes using a two-step protocol. Serum endocan levels were measured using a commercially available enzyme-linked immunosorbent assay (ELISA) kit. A p-value of <0.05 was considered statistically significant.

RESULTS

Serum endocan level was significantly higher in the GDM group than in healthy controls (168.46 ± 160.6 vs. 105.66 ± 26.52 pg/mL, respectively; p < 0.001). Serum endocan concentrations were positively correlated with the results of 50 g oral glucose challenge test (GCT) (p < 0.001). Receiver operating characteristic curve analysis showed that endocan with a cut-off point of 133.9 ng/dL indicated women with GDM with a sensitivity of 55.6% and specificity of 88.9% (area under the curve [AUC]: 0.737, 95% CI: 0.634-0.824). The overall differential performance of endocan according to the GDM groups was determined as 73.7% (p < 0.001). Maternal serum endocan level was positively correlated with fasting glucose, postprandial glucose, and glycated hemoglobin (HbA1c) (p < 0.001).

CONCLUSIONS

Elevated endocan levels in gestational diabetes were correlated with fasting glucose, postprandial glucose, HbA1c, and oral glucose tolerance test (OGTT) results. Despite the low sensitivity of 55.6% and the high specificity of 88.9%, we found a high differential performance rate indicating that serum endocan levels were important for the pathophysiology of GDM and should be investigated for the possibility of being a novel marker in larger populations.

The role of protein kinase R in placental inflammation, mtUPR and apoptosis

INTRODUCTION

Placental inflammation is implicated in the pathophysiology of many pregnancy complications, including fetal growth restriction, preeclampsia, gestational diabetes, and choriocarcinoma. Mitochondrial dysfunction, one of the outcomes of placental inflammation, is characterized by loss of membrane potential, accumulation of oxygen radicals, mitochondrial protein folding defects, and disturbances in mitochondrial dynamics. Protein kinase R (PKR) is stimulated by double-stranded RNA and bacterial endotoxins in the presence of pathogens and is a critical immune response enzyme. PKR is also correlated with the cell death response during endoplasmic reticulum stress. In this study, we aim to investigate the effects of PKR activity stimulated by lipopolysaccharide (LPS), and double-stranded RNA analog (Poly I:C) on mitochondrial unfolded protein response (mtUPR), mitochondrial membrane potential, apoptosis, and oxidative stress in placental trophoblasts.

METHODS

We applied LPS and Poly I:C to BeWo cells to induce PKR activation. In addition, cells were treated with 2-aminopurine (2-AP) to inhibit the kinase activity of PKR. Protein levels of ATP-dependent Clp protease proteolytic subunit (CLPP) and heat shock protein 60 (HSP60) were determined after treatments. Apoptotic markers were detected by real-time PCR and flow cytometry. PKR-induced reactive oxygen radicals (ROS) accumulation and mitochondrial membrane potential change were assessed by flow cytometry.

RESULTS

It was determined that PKR activation-induced apoptosis in BeWo cells by reducing the levels of mtUPR proteins (CLPP and HSP60) and caused a decrease in mitochondrial membrane potential. PKR inhibition was sufficient for decreases in apoptotic markers and caused a reduction in the ratio of depolarized and ROS (+) cells.

DISCUSSION

Our results showed that LPS and Poly I:C administration stimulated PKR in BeWo cells in vitro. Furthermore, PKR activation is correlated with the levels of proteins involved in mitochondrial homeostasis and apoptosis. Our findings will contribute to understanding the role of PKR activation in placental inflammation and related diseases.

The Role of Endocan in Cardiometabolic Disorders

Discovered two decades ago, endocan still represents an intriguing biomarker related to inflammation. Endocan is a soluble dermatan sulphate proteoglycan secreted by endothelial cells. Its expression is observed in tissues related to the enhanced proliferation, especially hepatocytes, lungs, kidneys, etc. Endocan has been investigated in many cardiometabolic disorders that are tightly connected with inflammation, such as type 2 diabetes mellitus, hypertension, atherosclerotic cardiovascular disease, kidney disease, obesity, polycystic ovary syndrome, metabolic syndrome, non-alcoholic fatty liver disease, etc. In this narrative, comprehensive review of the currently available literature, special attention will be paid to the role of endocan in the broad spectrum of cardiometabolic disorders. Since endocan has emerged as a novel endothelial dysfunction marker, the discovery of potential therapeutic strategies for patients with certain cardiometabolic risk factors would be of great importance to delay or even prevent the onset and progression of related complications, mainly cardiovascular.

Mono(2-ethylhexyl) phthalate induces transcriptomic changes in placental cells based on concentration, fetal sex, and trophoblast cell type

Phthalates are ubiquitous plasticizer chemicals found in consumer products. Exposure to phthalates during pregnancy has been associated with adverse pregnancy and birth outcomes and differences in placental gene expression in human studies. The objective of this research was to evaluate global changes in placental gene expression via RNA sequencing in two placental cell models following exposure to the phthalate metabolite mono(2-ethylhexyl) phthalate (MEHP). HTR-8/SVneo and primary syncytiotrophoblast cells were exposed to three concentrations (1, 90, 180 µM) of MEHP for 24 h with DMSO (0.1%) as a vehicle control. mRNA and lncRNAs were quantified using paired-end RNA sequencing, followed by identification of differentially expressed genes (DEGs), significant KEGG pathways, and enriched transcription factors (TFs). MEHP caused gene expression changes across all concentrations for HTR-8/SVneo and primary syncytiotrophoblast cells. Sex-stratified analysis of primary cells identified different patterns of sensitivity in response to MEHP dose by sex, with male placentas being more responsive to MEHP exposure. Pathway analysis identified 11 KEGG pathways significantly associated with at least one concentration in both cell types. Four ligand-inducible nuclear hormone TFs (PPARG, PPARD, ESR1, AR) were enriched in at least three treatment groups. Overall, we demonstrated that MEHP differentially affects placental gene expression based on concentration, fetal sex, and trophoblast cell type. This study confirms prior studies, as enrichment of nuclear hormone receptor TFs were concordant with previously published mechanisms of phthalate disruption, and generates new hypotheses, as we identified many pathways and genes not previously linked to phthalate exposure.

Effectiveness of Scutellaria baicalensis Georgi root in pregnancy-related diseases: A review

The root of Scutellaria baicalensis Georgi, also called Huangqin, is frequently used in traditional Chinese medicine. In ancient China, S. baicalensis root was used to clear heat, protect the fetus, and avoid a miscarriage for thousands of years. In modern times, pregnancy-related diseases can seriously affect maternal and fetal health, but few systematic studies have explored the mechanisms and potential targets of S. baicalensis root in the treatment of pregnancy-related diseases. Flavonoids (baicalein, wogonin and oroxylin A) and flavonoid glycosides (baicalin and wogonoside) are the main chemical components in the root of S. baicalensis. This study presents the current understanding of the major chemical components in the root of S. baicalensis, focusing on their traditional uses, potential therapeutic effects and ethnopharmacological relevance to pregnancy-related disorders. The mechanisms, potential targets and experimental models of S. baicalensis root for ameliorating pregnancy-related diseases, such as recurrent spontaneous abortion, preeclampsia, preterm birth, fetal growth restriction and gestational diabetes mellitus, are highlighted.

The Placental NLRP3 Inflammasome and Its Downstream Targets, Caspase-1 and Interleukin-6, Are Increased in Human Fetal Growth Restriction: Implications for Aberrant Inflammation-Induced Trophoblast Dysfunction

Fetal growth restriction (FGR) is commonly associated with placental insufficiency and inflammation. Nonetheless, the role played by inflammasomes in the pathogenesis of FGR is poorly understood. We hypothesised that placental inflammasomes are differentially expressed and contribute to the aberrant trophoblast function. Inflammasome gene expression profiles were characterised by real-time PCR on human placental tissues collected from third trimester FGR and gestation-matched control pregnancies (n = 25/group). The functional significance of a candidate inflammasome was then investigated using lipopolysaccharide (LPS)-induced models of inflammation in human trophoblast organoids, BeWo cells in vitro, and a murine model of FGR in vivo. Placental mRNA expression of NLRP3, caspases 1, 3, and 8, and interleukin 6 increased (>2-fold), while that of the anti-inflammatory cytokine, IL-10, decreased (<2-fold) in FGR compared with control pregnancies. LPS treatment increased NLRP3 and caspase-1 expression (>2-fold) in trophoblast organoids and BeWo cell cultures in vitro, and in the spongiotrophoblast and labyrinth in the murine model of FGR. However, the LPS-induced rise in NLRP3 was attenuated by its siRNA-induced down-regulation in BeWo cell cultures, which correlated with reduced activity of the apoptotic markers, caspase-3 and 8, compared to the control siRNA-treated cells. Our findings support the role of the NLRP3 inflammasome in the inflammation-induced aberrant trophoblast function, which may contribute to FGR.

Endocan, a Soluble Marker of Endothelial Cell Activation Is a Molecular Marker of Disease Severity in Women with Preeclampsia

Endocan is a proteoglycan secreted by activated endothelium that regulates angiogenesis via interaction with hepatocyte growth factor (HGF). We hypothesized that women diagnosed with preeclampsia (PE) and/or fetal growth restriction (FGR) have elevated circulating endocan concentrations in direct relationship with severity of clinical manifestations. Serum concentration of endocan and HGF were analyzed in 224 women grouped as healthy pregnant controls (P-CRL, n = 77), PE with severe features (sPE, n = 83), chronic hypertension (crHTN: n = 36), idiopathic FGR (n = 18), and healthy non-pregnant controls (NP-CRL, n = 7). Endocan and HGF measured by immunoassay were analyzed along with markers of inflammation, angiogenesis, and protein misfolding (urine congophilia). Endocan expression in the placenta and/or myometrium was studied by immunohistochemistry and real-time PCR. Compared to gestational age-matched P-CRL, women with early-onset sPE had higher circulating endocan concentrations. Among women with PE and/or FGR, endocan concentration correlated with soluble endoglin and urine congophilia but not with HGF or markers of inflammation or angiogenesis. In the placenta, endocan was expressed in villous and extravillous trophoblasts and endothelium. Intense endocan immunostaining was observed in plaque-like aggregations of sPE placentas complicated with FGR. In addition, thickened blood vessels in the myometrium of sPE patients stained positive for endocan. Women with early-onset sPE have elevated serum endocan likely reflecting chronic endothelial activation. Enhanced expression and/or deposition of endocan at the sites of placental injury and in remodeled maternal blood vessels supports a role for endocan in either vascular rescue or as a contributor to FGR and perhaps long-term cardiovascular morbidity.

Downregulationof circ_0001578 promotes gestational diabetes mellitus by inducing placental inflammation via the NF-κB and JNKs pathways

Gestational diabetes mellitus (GDM) is one of the most common diseases during pregnancy. Some patients with GDM have adverse pregnancy outcomes. However, the pathogenesis of GDM is very complex and not well understood. In this study, we characterized the expression and functions of a circular RNA, circ_0001578, in GDM. In particular, using qRT-PCR, we verified previous RNA-seq results showing that circ_0001578 is significantly downregulated in the placental villous tissues of pregnant women with GMD. We demonstrated that plasma exosome circ_0001578 expression in the second trimester effectively predicts GDM at 28 weeks. Furthermore, in HTR-8/SVneo trophoblasts, the downregulation of circ_0001578 inhibited proliferation and migration and induced apoptosis. These changes may induce chronic inflammation in the placenta. These effects of circ_0001578 downregulation may be mediated by the upregulation of the NF-κB and JNK pathways, combined with increased expression levels of IL-1, IL-6, IL-8, TNF-α, and CRP. Collectively, the downregulation of circ_0001578 may promote GDM by inducing chronic inflammation in the placenta via the NF-κB and JNK pathways. Furthermore, our findings support that circ_0001578 has potential to serve as an early marker of GDM.

Comparison of the maternal serum endocan levels in preterm premature rupture of membrane and normal pregnancy

OBJECTIVE

Endocan is a novel marker of endothelial inflammation. In this study, we aimed to show whether there was a significant difference between the endocan levels of pregnant women with and without preterm premature rupture of membranes (PPROM and non-PPROM). Also, we aimed to find a relation between endocan levels and the latent period.

MATERIAL AND METHODS

Pregnant women with PPROM between 28 and 34 weeks of gestation and those without PPROM with similar gestational weeks were included in the study. A total of 88 pregnant women, 44 with PROM and 44 healthy pregnancies, were evaluated. Demographic and obstetric features, leukocyte, and endocan levels of the study and control groups were compared.

RESULTS

The demographic features and obstetric history of both groups were similar. The mean leukocyte and endocan levels of the study group were higher than in the control group (p < 0.001 and 0.029, respectively). The leukocyte level was the only independent factor predicting PPROM after multivariate logistic regression analysis.

CONCLUSION

Although the endocan levels were higher in patients with PPROM, multivariate analysis showed that the only independent predictive factor was the leukocyte level.

Serum endocan levels in relation to traditional and non-traditional anthropometric indices in adult population

Background

Association between endocan and nontraditional anthropometric indices, as distinct cardiovascular disease risk factors, has not been examined in previous studies. Endocan is a novel inflammation biomarker with its higher levels involved in cardiometabolic diseases development. Taking into consideration that obesity is an independent risk factor for many cardiometabolic diseases, we aimed to explore the relationship between endocan levels and novel anthropometric indices [i.e., body adiposity index (BAI), cardiometabolic index (CMI), a body shape index, body roundness index, conicity index, lipid accumulation product index and visceral adiposity index] and traditional ones [i.e., waist circumference, hip circumference, body mass index, waist-to-height ratio and waist-to-hip ratio] in adult population.

Methods

A total of 177 participants were included. Anthropometric indices and biochemical parametres were measured.

Results

Univariate regression analysis demonstrated positive correlations of endocan and almost all anthropometric data. To explore independent associations of endocan and anthropometric parameters, the Model which fulfilled criteria for ordinal regression testing was created. Adjusted odds for BAI given in the Model (OR=1.120, 95% CI 1.036-1.212, P=0.004), demonstrated that a rise in BAI by 1 unit increased the probability of higher endocan concentration by 12%. As well, a rise in CMI for 1 unit, increased the probability for higher endocan levels for 2.6 times (OR=2.599, 95% CI 1.006-6.712, P=0.049). A total of 20.1% of variation in endocan levels could be explained by this Model.

Conclusions

Non-traditional obesity indices, BAI and CMI independently correlated with higher serum endocan levels in adult population.

The role of maternal-foetal interface inflammation mediated by NLRP3 inflammasome in the pathogenesis of recurrent spontaneous abortion

INTRODUCTION

Approximately half of the recurrent spontaneous abortions (RSAs) that remain unidentified to date may be closely related to inflammation. Our previous study found excessive NLRP3 inflammasomes in RSA patients. Here, we investigated further the role of inflammasomes in the maternal-foetal interface of RSA patients.

METHODS

Villous and decidual tissues were collected during uterine curettage. The trophoblast cell line TEV-1 was cultured with lipopolysaccharide (LPS) or low molecular weight heparin (LMWH), and then the macrophage cell line RAW264.7 was treated with trophoblast media. The expression and localisation of inflammasomes in tissues and cells were detected, and the migration and proliferation of cells were analysed.

RESULTS

A significantly increased expression of inflammasomes was observed in RSA tissues compared with those in the normal group, and it was more obvious in villous tissues than in decidual tissues. In TEV-1 cells, after LPS stimulation, the expression of inflammasomes was increased, but the cell activity was decreased, whereas in RAW264.7, both expression of inflammasomes and cell activity were increased in the LPS group. In addition, LMWH could inhibit the action of LPS in above cells.

DISCUSSION

In patients experiencing RSA, abnormal inflammatory response might be mediated by NLRP3 inflammasomes on the maternal-foetal interface, which may reduce trophoblast activity and promote macrophage activity, leading to early embryo implantation failure. LMWH is expected to treat RSA patients by blocking this process.

Disrupted placental serotonin synthetic pathway and increased placental serotonin: Potential implications in the pathogenesis of human fetal growth restriction

OBJECTIVES

Placental insufficiency contributes to altered maternal-fetal amino acid transfer, and thereby to poor fetal growth. An important placental function is the uptake of tryptophan and its metabolism to serotonin (5-HT) and kynurenine metabolites, which are essential for fetal development. We hypothesised that placental 5-HT content will be increased in pregnancies affected with fetal growth restriction (FGR).

METHODS

The components of the 5-HT synthetic pathway were determined in chorionic villus samples (CVS) from small-for gestation (SGA) and matched control collected at 10-12 weeks of human pregnancy; and in placentae from third trimester FGR and gestation-matched control pregnancies using the Fluidigm Biomarker array for mRNA expression, the activity of the enzyme TPH and 5-HT concentrations using an ELISA.

RESULTS

Gene expression for the rate limiting enzymes, TPH1 and TPH2; 5-HT transporter, SLC6A4; and 5-HT receptors HTR5A, HTR5B, HTR1D and HTR1E were detected in all CVS and third trimester placentae. No significant difference in mRNA was observed in SGA compared with control. Although there was no significant change in TPH1 mRNA, the mRNA of TPH2 and SLC6A4 was significantly decreased in FGR placentae (p < 0.05), while 5-HT receptor mRNA was significantly increased in FGR compared with control (p < 0.01). Placental TPH enzyme activity was significantly increased with a concomitant increase in the total placental 5-HT concentrations in FGR compared with control.

CONCLUSION

This study reports differential expression and activity of the key components of the 5-HT synthetic pathway associated with the pathogenesis of FGR. Further studies are required to elucidate the functional consequences of increased placental 5-HT in FGR pregnancies.

Pilot study of placental tissue collection, processing, and measurement procedures for large scale assessment of placental inflammation

Background

Placental dysfunction is related to many pregnancy complications, but collecting placental specimens for investigation in large scale epidemiologic studies is often infeasible. Standard procedures involving immediate collection after birth and snap freezing are often cost prohibitive. We aimed to collect pilot data regarding the feasibility and precision of a simpler approach, the collection of tissue samples following 24 hours of refrigeration of whole placentae at 4°C, as compared to the “gold standard” of snap freezing excised tissue within 40 minutes of delivery for the assessment of inflammatory cytokines.

Methods

Placentae were collected from 12 women after delivering live-born singleton babies via uncomplicated vaginal delivery. Two placentae were utilized to establish laboratory tissue processing and assay protocols. The other 10 placentae were utilized in a comparison of three tissue collection conditions. Specifically, key inflammatory cytokines were measured in 3 sections, representing three collection conditions. Sections 1 (full thickness) and 2 (excised prior to freezing) were obtained within 40 minutes of delivery and snap frozen in liquid nitrogen, and section 3 (full thickness) was obtained after refrigerating the placenta at 4°C for 24 hours.

Results

IL-6, IL-10, and IL-8 all had comparable concentrations and variability overall in all three section types. Levels of tumor necrosis factor alpha (TNF-α) were too low among samples to reliably measure using immunoassay.

Conclusions

Refrigeration of placentae prior to processing does not appear to compromise detection of these cytokines for purposes of large scale studies. These findings provide a framework and preliminary data for the study of inflammatory cytokines within the placenta in large scale and/or resource-limited settings.

Maternal 25-hydroxyvitamin D is inversely correlated with foetal serotonin

OBJECTIVE

Maternal vitamin D deficiency during pregnancy has been linked to impaired neurocognitive development in childhood. The mechanism by which vitamin D affects childhood neurocognition is unclear but may be via interactions with serotonin, a neurotransmitter involved in foetal brain development. In this study, we aimed to explore associations between maternal and foetal vitamin D concentrations, and foetal serotonin concentrations at term.

STUDY DESIGN AND MEASUREMENTS

Serum 25-hydroxyvitamin D (25(OH)D, nmol/l) and serotonin (5-HT, nmol/l) concentrations were measured in maternal and umbilical cord blood from mother-infant pairs (n = 64). Association between maternal 25(OH)D, cord 25(OH)D and cord serotonin was explored using linear regression, before and after adjusting for maternal serotonin levels. We also assessed the effects of siRNA knockdown of the vitamin D receptor (VDR) and administration of 10 nm 1,25-dihydroxyvitamin D₃ on serotonin secretion in human umbilical vein endothelial cells (HUVECs) in vitro.

RESULTS

We observed an inverse relationship between both maternal and cord 25(OH)D concentrations with cord serotonin concentrations. The treatment of HUVECs with 1,25-dihydroxyvitamin D₃ in vitro decreased the release of serotonin (193·9 ±14·8 nmol/l vs 458·9 ± 317·5 nmol/l, control, P < 0·05). Conversely, inactivation of VDR increased serotonin release in cultured HUVECs.

CONCLUSIONS

These observations provide the first evidence of an inverse relationship between maternal 25(OH)D and foetal serotonin concentrations. We propose that maternal vitamin D deficiency increases foetal serotonin concentrations and thereby contributes to longer-term neurocognitive impairment in infants and children.

Lipopolysaccharide and double stranded viral RNA mediate insulin resistance and increase system a amino acid transport in human trophoblast cells in vitro

INTRODUCTION

Inflammation and underlying low-grade maternal infection can impair insulin signalling and upregulate nutrient transport in the placenta which contribute to fetal overgrowth associated with GDM and/or obese pregnancies. There are, however, no studies on the role of infection on placental nutrient transport in pregnancies complicated by GDM and/or obesity. Thus, the aims of this study were to determine the effect of the bacterial product lipopolysaccharide (LPS) or the viral dsRNA analogue polyinosinic:polycytidylic acid (poly(I:C)) on the insulin signalling pathway and amino acid transport in primary human trophoblast cells.

METHODS

Human primary villous trophoblast cells were treated with LPS or poly(I:C). Protein expression of insulin signalling pathway proteins, insulin receptor (IR)-β, insulin receptor substrate (IRS)-1 and protein kinase B (also known as Akt), and phosphatidylinositol-4,5-bisphosphate 3-kinase p85α subunit (PI3K-p85α) protein were assessed by Western blotting. Glucose and amino acid uptake were assessed by radiolabelled assay. Western blotting and qRT-PCR were used to determine amino acid transporter protein and mRNA expression, respectively.

RESULTS

LPS and poly(I:C) significantly decreased phosphorylation of IR-β, IRS-1, Akt, total PI3K-p85α protein expression and glucose uptake. LPS and poly(I:C) also significantly increased expression of System A amino acid transporters SNAT1 and SNAT2, and System A-mediated uptake of amino acids.

DISCUSSION

LPS and poly(I:C) induces insulin resistance and increases amino acid uptake in human primary trophoblast cells. This suggests that the presence of low-grade maternal infection can contribute to excess placental nutrient availability and promote fetal overgrowth in pregnancies complicated by GDM and/or obesity.