Hyperglycemia impairs cytotrophoblast function via stress signaling

Associations of fasting plasma glucose and glycosylated hemoglobin levels at less than 24 weeks of gestation with hypertensive disorders of pregnancy: the BOSHI study

This study aimed to evaluate the associations of fasting plasma glucose (FPG) and glycosylated hemoglobin (HbA1c) levels at <24 weeks of gestation with hypertensive disorders of pregnancy (HDP) and compare the strengths of the associations of HDP with FPG and HbA1c levels. Totally, 1,178 participants were included in this prospective cohort study. HDP, FPG, HbA1c, and potential confounding factors were included in multiple logistic regression models. The number of HDP cases was 136 (11.5%). When FPG and HbA1c were included in the model separately, quartile 4 (Q4) of FPG (87-125 mg/dL) and HbA1c (5.2-6.3% [33-45 mmol/mol]) levels had higher odds of HDP than quartile 1. The odds ratios (ORs) were 1.334 (95% confidence interval [CI]: 1.002-1.775) for Q4 of FPG and 1.405 (95% CI: 1.051-1.878) for Q4 of HbA1c. When the participants were divided into two categories based on the cut-off value with the maximum Youden Index of FPG or HbA1c, the ORs for high FPG (≥84 mg/dL) or high HbA1c (≥5.2% [33 mmol/mol]) were 1.223 (95% CI: 1.000-1.496) and 1.392 (95% CI: 1.122-1.728), respectively. When both FPG and HbA1c were included in the model simultaneously, the statistical significance of Q4 of FPG disappeared, whereas that of HbA1c remained. In two-category models, the same results were obtained. High FPG and HbA1c levels at <24 weeks of gestation were risk factors for HDP in pregnant Japanese women. In addition, high HbA1c levels were more strongly associated with HDP than high FPG levels.

Pravastatin Protects Cytotrophoblasts from Hyperglycemia-Induced Preeclampsia Phenotype

There are no effective therapies to prevent preeclampsia (PE). Pravastatin shows promise by attenuating processes associated with PE such as decreased cytotrophoblast (CTB) migration, aberrant angiogenesis, and increased oxidative stress. This study assesses the effects of pravastatin on hyperglycemia-induced CTB dysfunction.

METHODS

Human CTB cells were treated with 100, 150, 200, 300, or 400 mg/dL glucose for 48 h. Some cells were pretreated with pravastatin (1 µg/mL), while others were cotreated with pravastatin and glucose. The expression of urokinase plasminogen activator (uPA), plasminogen activator inhibitor 1 (PAI-1) mRNA, vascular endothelial growth factor (VEGF), placenta growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1), and soluble endoglin (sEng) were measured. CTB migration was assayed using a CytoSelect migration assay kit. Statistical comparisons were performed using an analysis of variance with Duncan's post hoc test.

RESULTS

The hyperglycemia-induced downregulation of uPA was attenuated in CTB cells pretreated with pravastatin at glucose levels > 200 mg/dL and cotreated at glucose levels > 300 mg/dL (p < 0.05). Hyperglycemia-induced decreases in VEGF and PlGF and increases in sEng and sFlt-1 were attenuated in both the pretreatment and cotreatment samples regardless of glucose dose (p < 0.05). Pravastatin attenuated hyperglycemia-induced dysfunction of CTB migration.

CONCLUSIONS

Pravastatin mitigates stress signaling responses in hyperglycemic conditions, weakening processes leading to abnormal CTB migration and invasion associated with PE in pregnancy.

Placental Senescence and the Two-Stage Model of Preeclampsia

In this review, we summarize how an increasingly stressed and aging placenta contributes to the maternal clinical signs of preeclampsia, a potentially lethal pregnancy complication. The pathophysiology of preeclampsia has been conceptualized in the two-stage model. Originally, highlighting the importance of poor placentation for early-onset preeclampsia, the revised two-stage model explains late-onset preeclampsia as well, which is often preceded by normal placentation. We discuss how cellular senescence in the placenta may fit with the framework of the revised two-stage model of preeclampsia pathophysiology and summarize potential cellular and molecular mechanisms, including effects on placental and maternal endothelial function. Cellular senescence may occur in response to inflammatory processes and oxidative, mitochondrial, or endoplasmic reticulum stress and chronic stress induce accelerated, premature placental senescence. In preeclampsia, both circulating and tissue-based senescence markers are present. We suggest that aspirin prophylaxis, commonly recommended from the first trimester onward for women at risk of preeclampsia, may affect placentation and possibly mechanisms of placental senescence, thus attenuating the risk of preeclampsia developing clinically. We propose that biomarkers of placental dysfunction and senescence may contribute to altered preventive strategies, including discontinuation of aspirin at week 24-28 depending on placenta-associated biomarker risk stratification.

The Role of Sirtuin-1 (SIRT1) in the Physiology and Pathophysiology of the Human Placenta

Sirtuins, especially SIRT1, play a significant role in regulating inflammatory response, autophagy, and cell response to oxidative stress. Since their discovery, sirtuins have been regarded as anti-ageing and longevity-promoting enzymes. Sirtuin-regulated processes seem to participate in the most prevalent placental pathologies, such as pre-eclampsia. Furthermore, more and more research studies indicate that SIRT1 may prevent pre-eclampsia development or at least alleviate its manifestations. Having considered this, we reviewed recent studies on the role of sirtuins, especially SIRT1, in processes determining normal or abnormal development and functioning of the placenta.

Poor glucose control and markers of placental dysfunction correlate with increased circulating fetal microchimerism in diabetic pregnancies

Fetal microchimerism (FMc) arises during pregnancy as fetal cells enter maternal circulation and remain decades postpartum. Circulating FMc is increased in preeclampsia, fetal growth restriction, and as we recently showed, is associated with biomarkers of placental dysfunction in normotensive term pregnancies. Diabetes mellitus (DM) also correlates with placental dysfunction. We hypothesize that poor glucose control and markers of placental dysfunction are associated with increased circulating FMc in diabetic pregnancies. We included 122 pregnancies preceding active labor (pregestational DM, n = 77, gestational DM (GDM), n = 45) between 2001 and 2017. Maternal and fetal samples were genotyped for various human leukocyte antigen (HLA) loci, and other polymorphisms to identify fetus-specific alleles. We used validated polymerase chain reaction (PCR) assays to quantify FMc in maternal peripheral blood buffy coat. Negative binomial regression with adjustment for confounders was used to assess FMc quantity. In pregestational DM, increased circulating FMc correlated with elevation of HbA1c (≥ 6.0 %) (detection rate ratio (DRR) = 4.9, p = 0.010) and a 1000 pg/mL rise in the anti-angiogenic biomarker soluble fms-like tyrosine kinase-1 (sFlt-1) (DRR = 1.1, p = 0.011). In GDM, increased FMc correlated with elevated 2-hour oral glucose tolerance test results (DRR = 2.3, p = 0.046) and birthweight < 10th or > 90th percentile (DRR = 4.2, p = 0.049). These findings support our novel hypothesis that FMc correlates with poor glucose control and various aspects of placental dysfunction in DM. Whether increased FMc in pregnancies with poor glucose control and placental dysfunction contributes to the risk of preeclampsia in diabetic pregnancies and to the increased risk of chronic cardiovascular disease later in life remains to be investigated.

High Glucose Promotes Inflammation and Weakens Placental Defenses against E. coli and S. agalactiae Infection: Protective Role of Insulin and Metformin

Placentas from gestational diabetes mellitus (GDM) patients undergo significant metabolic and immunologic adaptations due to hyperglycemia, which results in an exacerbated synthesis of proinflammatory cytokines and an increased risk for infections. Insulin or metformin are clinically indicated for the treatment of GDM; however, there is limited information about the immunomodulatory activity of these drugs in the human placenta, especially in the context of maternal infections. Our objective was to study the role of insulin and metformin in the placental inflammatory response and innate defense against common etiopathological agents of pregnancy bacterial infections, such as E. coli and S. agalactiae, in a hyperglycemic environment. Term placental explants were cultivated with glucose (10 and 50 mM), insulin (50–500 nM) or metformin (125–500 µM) for 48 h, and then they were challenged with live bacteria (1 × 105 CFU/mL). We evaluated the inflammatory cytokine secretion, beta defensins production, bacterial count and bacterial tissue invasiveness after 4–8 h of infection. Our results showed that a GDM-associated hyperglycemic environment induced an inflammatory response and a decreased beta defensins synthesis unable to restrain bacterial infection. Notably, both insulin and metformin exerted anti-inflammatory effects under hyperglycemic infectious and non-infectious scenarios. Moreover, both drugs fortified placental barrier defenses, resulting in reduced E. coli counts, as well as decreased S. agalactiae and E. coli invasiveness of placental villous trees. Remarkably, the double challenge of high glucose and infection provoked a pathogen-specific attenuated placental inflammatory response in the hyperglycemic condition, mainly denoted by reduced TNF-α and IL-6 secretion after S. agalactiae infection and by IL-1β after E. coli infection. Altogether, these results suggest that metabolically uncontrolled GDM mothers develop diverse immune placental alterations, which may help to explain their increased vulnerability to bacterial pathogens.

The Role of Peroxisome Proliferator-Activated Receptors in Preeclampsia

Preeclampsia is a common pregnancy-related hypertensive disorder. Often presenting as preexisting or new-onset hypertension complicated by proteinuria and/or end-organ dysfunction, preeclampsia significantly correlates with maternal and perinatal morbidity and mortality. Peroxisome proliferator-activated receptors (PPARs) are nuclear receptor proteins that regulate gene expression. In order to investigate the role of PPARs in the pathophysiology of preeclampsia, we conducted a literature review using the MEDLINE and LIVIVO databases. The search terms "peroxisome proliferator-activated receptor", "PPAR", and "preeclampsia" were employed and we were able to identify 35 relevant studies published between 2002 and 2022. Different study groups reached contradictory conclusions in terms of PPAR expression in preeclamptic placentae. Interestingly, PPARγ agonists alone, or in combination with well-established pharmaceutical agents, were determined to represent novel, potent anti-preeclamptic treatment alternatives. In conclusion, PPARs seem to play a significant role in preeclampsia.

Impact of Gestational Diabetes and Hypertension Disorders of Pregnancy on Neonatal Outcomes in Twin Pregnancies Based on Chorionicity

OBJECTIVES

The objective of this study was to investigate the impact of the co-existence of gestational diabetes (GDM) and hypertension disorders of pregnancy (HDP) on neonatal outcomes in twin pregnancies based on chorionicity.

METHODS

A retrospective study of 1398 women with twin pregnancies was performed between January 2016 and December 2021. The effects of GDM and HDP on neonatal outcomes were assessed by logistic regression models. An additional stratified analysis was conducted to estimate the effects based on chorionicity (monochorionic (MC) and dichorionic (DC)).

RESULTS

The incidence of the co-existence of GDM and HDP was 3.8%. The presence of GDM increased the likelihood of HDP only in women with MC twin pregnancies (OR, 2.13; 95% CI 1.08-4.19). After adjustments, co-existence of GDM and HDP was positively associated with gestational age (β, 1.06; 95% CI 0.43-1.69) and birthweight (β, 174.90; 95% CI 8.91-340.89) in MC twin pregnancies, while no associations were found between co-existence of GDM and HDP and neonatal outcomes in DC twin pregnancies. However, HDP was negatively associated with birthweight (β, -156.97; 95% CI (-257.92, -56.02)) and positively associated with small-for-gestational-age (SGA) (OR, 2.03; 95% CI 1.02-4.03) and discordant twins (OR, 2.83; 95% CI 1.78-4.48) in DC twin pregnant women without GDM.

CONCLUSIONS

Our results suggested that GDM leads to an increased risk of HDP only in MC twin pregnancies, but GDM seemed to attenuate the adverse effects of HDP on perinatal outcomes in both MC and DC twin pregnancies. Further investigation is needed to explain these intriguing findings.

Hyperglycemia disturbs trophoblast functions and subsequently leads to failure of uterine spiral artery remodeling

Uterine spiral artery remodeling is necessary for fetal growth and development as well as pregnancy outcomes. During remodeling, trophoblasts invade the arteries, replace the endothelium and disrupt the vascular smooth muscle, and are strictly regulated by the local microenvironment. Elevated glucose levels at the fetal-maternal interface are associated with disorganized placental villi and poor placental blood flow. Hyperglycemia disturbs trophoblast proliferation and invasion via inhibiting the epithelial-mesenchymal transition, altering the protein expression of related proteases (MMP9, MMP2, and uPA) and angiogenic factors (VEGF, PIGF). Besides, hyperglycemia influences the cellular crosstalk between immune cells, trophoblast, and vascular cells, leading to the failure of spiral artery remodeling. This review provides insight into molecular mechanisms and signaling pathways of hyperglycemia that influence trophoblast functions and uterine spiral artery remodeling.

Prediction of preeclampsia based on maternal serum endoglin level in women with pregestational diabetes mellitus

PURPOSE

To evaluate the level of soluble endoglin (sEng) in pregnant women with pregestational diabetes mellitus (DM) and to assess its predictive value for preeclampsia development.

METHODS

Ninety pregnant women were enrolled in the study forming five comparison groups: type 1 DM (not planned, n = 20; planned, n = 20), type 2 DM (diet, n = 15; insulin therapy, n = 20), and the control group (n = 15). The primary outcome was clinically confirmed preeclampsia. Maternal serum concentrations of sEng were measured at 11+0-13+6 and 30+0-33+6 weeks.

RESULTS

sEng level was elevated in all patients with pregestational DM compared to the control group. Its plasma concentration increased with gestational age and in case of preeclampsia development. In patients with type 1 DM, serum sEng level did not depend on the presence of preeclampsia. This is evidence of severe metabolic disorder and endothelial dysfunction in these patients. The addition of sEng level to logistic models considering established risk factors (body mass index + age + HbA1c level) in the first and third trimesters significantly improved their performance for preeclampsia prediction.

CONCLUSIONS

Eng level may become an important marker for early prediction of preeclampsia in women with pregestational DM.

Preconception hemoglobin A1c in healthy women is not associated with fecundability or pregnancy loss

Objective

To examine the relationship of preconception hemoglobin A1c, a marker of cumulative exposure to glucose over the preceding 2–3 months, with time to pregnancy, pregnancy loss, and live birth among fecund women without diagnosed diabetes or other medical diseases.

Design

A secondary analysis of a prospective cohort of women participating in the Effects of Aspirin in Gestation and Reproduction (EAGeR) trial.

Setting

Four US academic medical centers.

Patient(s)

A total of 1,194 healthy women aged 18–40 years with a history of one or two pregnancy losses attempting spontaneous conception were observed for up to six cycles while attempting pregnancy and throughout pregnancy if they conceived.

Intervention(s)

Not applicable.

Main Outcome Measure(s)

Time to pregnancy, human chorionic gonadotropin pregnancy, clinical pregnancy, pregnancy loss, and live birth.

Result(s)

Although increasing preconception A1c level was associated with reduced fecundability (fecundability odds ratio [FOR] per unit increase in A1c 0.74; 95% confidence interval [CI] 0.57, 0.96) in unadjusted models and models adjusted for age, race, smoking and treatment arm (FOR 0.79; 95% CI 0.60, 1.04), results were attenuated after further adjustment for body mass index (FOR 0.91; 95% CI 0.68, 1.21). Preconception A1c levels among women without diagnosed diabetes were not associated with live birth or pregnancy loss.

Conclusions(s)

Among healthy women without diagnosed diabetes, we observed no association of A1c with live birth or pregnancy loss. The association between A1c and fecundability was influenced by body mass index, a strong risk factor for both diabetes and infertility. These data support current recommendations that preconception A1c screening should be reserved for patients with risk factors for diabetes.

Clinical Trial Registration Number

ClinicalTrials.gov: NCT00467363.

Nesfatin-1 alleviates high glucose/high lipid-induced injury of trophoblast cells during gestational diabetes mellitus

Gestational diabetes mellitus (GDM) is a common disease in pregnant women, imposing risks on both mother and fetus. Dysregulated nesfatin-1 has been observed in women with GDM, but the specific role of nesfatin-1 underlying the pathological process of GDM is unclear. The main objective of this study is to investigate the role and the molecular mechanism of nesfatin-1 in GDM. HTR-8/SVneo cells were treated with high glucose (HG)/high lipid (HL) to mimic the injured trophoblast of GDM in vitro. Cell viability, cytotoxicity and apoptosis were measured using CCK-8, LDH and TUNEL assays, respectively. The levels of inflammatory cytokines and antioxidant factors were detected using their commercial kits. ATP level and cytochrome c were determined with corresponding detecting kits. Quantitative real-time PCR and Western blot were performed to detect the expression of corresponding genes. The results showed that nesfatin-1 was downregulated upon HG/HL stimulation. Nesfatin-1 treatment greatly alleviated HG/HL-induced cell viability loss, cytotoxicity, inflammatory response, oxidative stress, and apoptosis in HTR-8/SVneo cells. In addition, nesfatin-1 promoted ATP generation, reduced the leakage of cytochrome c from mitochondria to cytoplasm, and upregulated mitochondrial transcription factor A (TFAM) and nuclear respiratory factor 1 (NRF1), alleviating mitochondrial dysfunction. Furthermore, nesfatin-1 inhibited p38 MAPK signaling. p79350, an agonist of p38 MAPK signaling, remarkably hindered the protective role of nesfatin-1 in HG/HL-induced HTR-8/SVneo cells. In conclusion, nesfatin-1 exerted a protective effect on GDM model in vitro, by regulating p38 MAPK signaling pathway, providing novel insights of treating GDM.

p66Shc-mediated oxidative stress is involved in gestational diabetes mellitus

BACKGROUND

Gestational diabetes mellitus (GDM) is associated with a heightened level of oxidative stress, which is characterized by the overproduction of reactive oxygen species (ROS) from mitochondria. Previous studies showed that mitochondrial dysfunction is regulated by dynamin-related protein 1 (Drp1) and p66Shc in GDM.

AIM

The aim was to investigate the expression of Drp1 and p66Shc and their possible mechanisms in the pathogenesis of GDM.

METHODS

A total of 30 pregnant women, 15 with GDM and 15 without GDM, were enrolled. Peripheral blood mononuclear cells and placental tissue were collected. The human JEG3 trophoblast cell line was cultivated in 5.5 mmol/L or 30 mmol/L glucose and transfected with wild-type (wt)-p66Shc and p66Shc siRNA. P66Shc and Drp1 mRNA levels were detected by quantitative real-time polymerase chain reaction. The expression of p66Shc and Drp1 was assayed by immunohistochemistry and western blotting. ROS was assayed by dihydroethidium staining.

RESULTS

The p66Shc mRNA level was increased in the serum (P < 0.01) and placentas (P < 0.01) of women with GDM, and the expression of Drp1 mRNA and protein were also increased in placentas (P < 0.05). In JEG3 cells treated with 30 mmol/L glucose, the mRNA and protein expression of p66Shc and Drp1 were increased at 24 h (both P < 0.05), 48 h (both P < 0.01) and 72 h (both P < 0.001). ROS expression was also increased. High levels of Drp1 and ROS expression were detected in JEG3 cells transfected with wt-p66Shc (P < 0.01), and low levels were detected in JEG3 cells transfected with p66Shc siRNA (P < 0.05).

CONCLUSION

The upregulated expression of Drp1 and p66shc may contribute to the occurrence and development of GDM. Regulation of the mitochondrial fusion-fission balance could be a novel strategy for GDM treatment.

Immunoendocrine Dysregulation during Gestational Diabetes Mellitus: The Central Role of the Placenta

Gestational Diabetes Mellitus (GDM) is a transitory metabolic condition caused by dysregulation triggered by intolerance to carbohydrates, dysfunction of beta-pancreatic and endothelial cells, and insulin resistance during pregnancy. However, this disease includes not only changes related to metabolic distress but also placental immunoendocrine adaptations, resulting in harmful effects to the mother and fetus. In this review, we focus on the placenta as an immuno-endocrine organ that can recognize and respond to the hyperglycemic environment. It synthesizes diverse chemicals that play a role in inflammation, innate defense, endocrine response, oxidative stress, and angiogenesis, all associated with different perinatal outcomes.

Membrane and soluble endoglin role in cardiovascular and metabolic disorders related to metabolic syndrome

Membrane endoglin (Eng, CD105) is a transmembrane glycoprotein essential for the proper function of vascular endothelium. It might be cleaved by matrix metalloproteinases to form soluble endoglin (sEng), which is released into the circulation. Metabolic syndrome comprises conditions/symptoms that usually coincide (endothelial dysfunction, arterial hypertension, hyperglycemia, obesity-related insulin resistance, and hypercholesterolemia), and are considered risk factors for cardiometabolic disorders such as atherosclerosis, type II diabetes mellitus, and liver disorders. The purpose of this review is to highlight current knowledge about the role of Eng and sEng in the disorders mentioned above, in vivo and in vitro extent, where we can find a wide range of contradictory results. We propose that reduced Eng expression is a hallmark of endothelial dysfunction development in chronic pathologies related to metabolic syndrome. Eng expression is also essential for leukocyte transmigration and acute inflammation, suggesting that Eng is crucial for the regulation of endothelial function during the acute phase of vascular defense reaction to harmful conditions. sEng was shown to be a circulating biomarker of preeclampsia, and we propose that it might be a biomarker of metabolic syndrome-related symptoms and pathologies, including hypercholesterolemia, hyperglycemia, arterial hypertension, and diabetes mellitus as well, despite the fact that some contradictory findings have been reported. Besides, sEng can participate in the development of endothelial dysfunction and promote the development of arterial hypertension, suggesting that high levels of sEng promote metabolic syndrome symptoms and complications. Therefore, we suggest that the treatment of metabolic syndrome should take into account the importance of Eng in the endothelial function and levels of sEng as a biomarker and risk factor of related pathologies.

Upregulation of IL-15 in the placenta alters trophoblasts behavior contributing to gestational diabetes mellitus

Background

Interleukin-15 (IL-15), a member of the ‘four α-helix bundle’ cytokine family, has been associated with many inflammatory and metabolic diseases. Abnormal expression of IL-15 has been linked to the occurrence and development of obesity and diabetes. However, there is a paucity of research on the involvement of IL-15 in Gestational Diabetes Mellitus (GDM). This study aims at investigating the role of IL-15 in the pathogenesis of GDM.

Results

IL-15 was consistently expressed in the placenta throughout pregnancy and dynamically changed with pregnancy progress. Trophoblasts have been identified as the major source of IL-15 in the placenta. Expression of IL-15 was significantly increased in the placenta of GDM and in the trophoblasts cultured with high glucose (HG). In our study, expression of IL-15 in the placenta was positively correlated with blood glucose concentration of 75 g Oral Glucose Tolerance Test (OGTT), and was inversely correlated with weight of newborns. Further investigations in vitro showed that exogenous addition of IL-15 promoted trophoblasts proliferation, improved invasion and tube formation ability by activating the JAK/STAT signaling pathway, which be blocked by JAK inhibitors.

Conclusion

Our results demonstrated that IL-15 expression in the placenta was dynamically changing during pregnancy, and it was upregulated in the placenta of GDM patients. Furthermore, IL-15 altered the biological behavior of trophoblasts through JAK/STAT signaling pathway in vitro, and may contributed to the placental pathology of GDM. Our findings provide a new direction for studying the pathophysiological changes of placenta in GDM.

Role of Peroxisome Proliferator-Activated Receptors (PPARs) in Trophoblast Functions

Peroxisome proliferator-activated receptors (PPARα, PPARβ/δ, and PPARγ) belong to the transcription factor family, and they are highly expressed in all types of trophoblast during pregnancy. The present review discusses currently published papers that are related to the regulation of PPARs via lipid metabolism, glucose metabolism, and amino acid metabolism to affect trophoblast physiological conditions, including differentiation, maturation, secretion, fusion, proliferation, migration, and invasion. Recent pieces of evidence have proven that the dysfunctions of PPARs in trophoblast lead to several related pregnancy diseases such as recurrent miscarriage, preeclampsia, intrauterine growth restriction, and gestational diabetes mellitus. Moreover, the underlying mechanisms of PPARs in the control of these processes have been discussed as well. Finally, this review's purposes are to provide more knowledge about the role of PPARs in normal and disturbed pregnancy with trophoblast, so as to find PPAR ligands as a potential therapeutic target in the treatment and prevention of adverse pregnancy outcomes.

Placental expression of endoglin, placental growth factor, leptin, and hypoxia-inducible factor-1 in diabetic pregnancy and pre-eclampsia

OBJECTIVE

To evaluate a level of expression of endoglin (Eng), leptin (Lep), placental growth factor (PlGF), and hypoxia-inducible factor-1alpha (HIF-1α) in placenta among women with pre-eclampsia and diabetes mellitus (DM), considering the method of glycemia correction and preconception care.

MATERIALS AND METHODS

A retrospective cohort study was conducted. A total of 124 women were divided into following groups: type 1 DM (n = 40), type 2DM (n = 31), gestational DM (n = 33), pre-eclampsia without DM (PE) (n = 10) and the control group (n = 10). The histochemical study was performed by using primary monoclonal antibodies to Eng, PlGF, Lep, and HIF-1α (Abcam, UK).

RESULTS

The highest level of placental expression of Eng was observed in the PE group (20.34%). The same trend was also typical for T1DM (not planned) and insulin-treated groups: T2DM and GDM. An amount of cell with an PlGF expression was significantly higher in the control group (12.2%), while the lowest was observed in the pre-eclampsia group (1.18%) and T1DM (not planned) (1.26%). The placental leptin expression within each DM group was increased among the patients with unplanned pregnancy and those who received insulin therapy. We observed the lowest Lep expression in the PE group (6.3%). High level of HIF-1α expression was detected in T1DM (not planned) (30.44%) and PE (29.64%) as compared to the control group (11.62%). In T2DM and GDM insulin groups, the HIF-1α expression was significantly higher as compared to diet groups.

CONCLUSION

The obtained data show that DM and pre-eclampsia are associated with changes in angiogenic and metabolic placental factor expressions. The degree of changes depends on preconception care and the control of glycemia level during pregnancy.

Poorly controlled diabetes mellitus alters placental structure, efficiency, and plasticity

INTRODUCTION

The hemochorial placenta provides a critical barrier at the maternal-fetal interface to modulate maternal immune tolerance and enable gas and nutrient exchange between mother and conceptus. Pregnancy outcomes are adversely affected by diabetes mellitus; however, the effects of poorly controlled diabetes on placental formation, and subsequently fetal development, are not fully understood.

RESEARCH DESIGN AND METHODS

Streptozotocin was used to induce hyperglycemia in pregnant rats for the purpose of investigating the impact of poorly controlled diabetes on placental formation and fetal development. The experimental paradigm of hypoxia exposure in the pregnant rat was also used to assess properties of placental plasticity. Euglycemic and hyperglycemic rats were exposed to ambient conditions (~21% oxygen) or hypoxia (10.5% oxygen) beginning on gestation day (gd) 6.5 and sacrificed on gd 13.5. To determine whether the interaction of hyperglycemia and hypoxia was directly altering trophoblast lineage development, rat trophoblast stem (TS) cells were cultured in high glucose (25 mM) and/or exposed to low oxygen (0.5% to 1.5%).

RESULTS

Diabetes caused placentomegaly and placental malformation, decreasing placental efficiency and fetal size. Elevated glucose disrupted rat TS cell differentiation in vitro. Evidence of altered trophoblast differentiation was also observed in vivo, as hyperglycemia affected the junctional zone transcriptome and interfered with intrauterine trophoblast invasion and uterine spiral artery remodeling. When exposed to hypoxia, hyperglycemic rats showed decreased proliferation and ectoplacental cone development on gd 9.5 and complete pregnancy loss by gd 13.5. Furthermore, elevated glucose concentrations inhibited TS cell responses to hypoxia in vitro.

CONCLUSIONS

Overall, these results indicate that alterations in placental development, efficiency, and plasticity could contribute to the suboptimal fetal outcomes in offspring from pregnancies complicated by poorly controlled diabetes.

Mechanism of Placenta Damage in Gestational Diabetes Mellitus by Investigating TXNIP of Patient Samples and Gene Functional Research in Cell Line

INTRODUCTION

Gestational diabetes mellitus (GDM) is a gestational complication that affects maternal and child health. The placenta provides the fetus with the necessary nutrition and oxygen and takes away the metabolic waste. Patients with GDM are diagnosed and treated merely on the basis of the blood glucose level; this approach does nothing to help evaluate the status of the placenta, which is worth noting in GDM. The purpose of this research was to clarify the relation between thioredoxin-interacting protein (TXNIP) and reactive oxygen species (ROS) in the placenta of patients with GDM, which has thus far remained unclear.

METHODS

The expression of TXNIP in the placentas of 10 patients with GDM and 10 healthy puerperae (control group) was investigated via immunofluorescence. The relation among TXNIP, ROS, and the function of mitochondria was explored in HTR-8/SVneo cells stimulated by high glucose (HG).

RESULTS

The results showed the expression of TXNIP in the placentas of patients with GDM was higher than that in the control group, and the expression of TXNIP in HTR-8/SVneo cells treated with HG was higher than that in the control group, causing the accumulation of ROS and changes of mitochondria, promoting apoptosis and inhibition of migration.

CONCLUSIONS

High expression of TXNIP caused by HG mediates the increasing ROS and the mitochondria dysfunction in GDM; this impairs the function of the placenta and is the basis for the prediction of perinatal outcome.

Differential placental ceramide levels during gestational diabetes mellitus (GDM)

BACKGROUND

Gestational diabetes mellitus (GDM) is associated with important factors that influence fetal development. Sphingolipids are known to be associated with the development of diabetes. Our objective was to examine ceramide, a key sphingolipid, hyperosmolarity, and apoptosis in placentas from GDM patients treated with insulin or diet.

METHODS

Ceramide levels were assessed in placental tissues using immunohistochemistry. Immunoblot was performed to quantify serine palmitoyltransferase (SPT), the rate-limiting enzyme in ceramide biosynthesis, NFAT5, SMIT, AR, caspase 3 and the X-linked inhibitor of apoptosis. Trophoblast cells were treated with insulin or ceramide and assessments for mitochondrial respiration, caspase 3 and XIAP were also performed.

RESULTS

Immunohistochemistry showed increased ceramides in the placental villous trophoblasts of the insulin-treated GDM patients. Nuclear SPT was upregulated only in the insulin-treated GDM placenta when compared to controls. Nuclear NFAT5 was also increased in the GDM placenta. Active caspase 3 was elevated in placentas from both insulin- and diet-treated GDM patients. Mitochondrial respiration was decreased in trophoblasts treated with ceramide. Active caspase was not changed while XIAP protein was increased in trophoblasts treated with ceramide.

CONCLUSIONS

Our findings confirm the presence of ceramide in the human placenta of control and GDM patients. Furthermore, we conclude that ceramide is increased in the placental trophoblast during insulin treatment and that its upregulation correlates with elevated NFAT5, SMIT, increased apoptosis and decreased trophoblast mitochondrial respiration.

Knockdown of CYP1B1 suppresses the behavior of the extravillous trophoblast cell line HTR-8/SVneo under hyperglycemic condition

Introduction: Trophoblast plays a vital role in the embryonic implantation and function of the placenta. Exposure to a hyperglycemic environment results in the abnormal function of trophoblasts during fetoplacental development, which leads to maternal complications and poor fetal outcomes. However, the precise mechanisms of placental pathology during hyperglycemia remain elusive. We investigated the role of CYP1B1 in the functional behavior of the extravillous trophoblast (EVT) cell line HTR-8/SVneo under hyperglycemic condition.Methods: We determined the expression of CYP1B1 via real-time polymerase chain reaction and Western blot. Specific CYP1B1 inhibitors and small interfering RNA were used to knockdown CYP1B1, whereas an agonist and an adenovirus were used to overexpress CYP1B1. The proliferation, migration, and invasion of the EVT cell line (i.e. HTR-8/SVneo) were assessed via colony formation, 5-ethynyl-2-deoxyuridine, wound healing, and transwell assay.Results: CYP1B1 is highly expressed in placentas from women with gestational diabetes mellitus. The blockage of CYP1B1 inhibits EVT activities induced by hyperglycemia in vitro, including proliferation, migration, and invasion, whereas the exogenous expression of CYP1B1 exhibits the opposite effects.Discussion: Our study may offer a new method for regulating EVT motility under hyperglycemic condition via CYP1B1.

The role of Sirtuin1-PPARγ axis in placental development and function

Placental development is important for proper in utero growth and development of the fetus, as well as maternal well-being during pregnancy. Abnormal differentiation of placental epithelial cells, called trophoblast, is at the root of multiple pregnancy complications, including miscarriage, the maternal hypertensive disorder preeclampsia and intrauterine growth restriction. The ligand-activated nuclear receptor, PPARγ, and nutrient sensor, Sirtuin-1, both play a role in numerous pathways important to cell survival and differentiation, metabolism and inflammation. However, each has also been identified as a key player in trophoblast differentiation and placental development. This review details these studies, and also describes how various stressors, including hypoxia and inflammation, alter the expression or activity of PPARγ and Sirtuin-1, thereby contributing to placenta-based pregnancy complications.

Diabetes and pre-eclampsia affecting pregnancy: a retrospective cross-sectional study

The interaction between pre-eclampsia and diabetes mellitus (DM) is far from being completely understood. In this study, we compared normal pregnancies with those complicated with pre-eclampsia, gestational DM, and/or pre-existing diabetes to assess the effects of hyperglycemia on placental development. AnInstitutional Review Board (IRB) approved retrospective cross-sectional study with 621 subjects was performed. Statistical analysis was performed using Duncan's post hoc test and analysis of variance. Regardless of diabetes status, patients with pre-eclampsia delivered prematurely. Patients in the group with pre-eclampsia and pregestational diabetes delivered much earlier, at 35.0±0.4 weeks, when compared with the patients that had pre-eclampsia with gestational diabetes and pre-eclampsia with no diabetes (*P<0.05 for each). Additionally, patients with pre-existing diabetes who developed pre-eclampsia delivered smaller babies than those with pre-existing diabetes without pre-eclampsia (1.00±0.03, P<0.05 for each). Pre-existing diabetes with added insult of pre-eclampsia led to fetal growth restriction. This outcome validates the understanding that elevated glucose earlier in pregnancy alters placentogenesis and leads to fetal growth restriction.

Systematic Characterization of Autophagy in Gestational Diabetes Mellitus

Autophagy is a dynamic process that degrades and recycles cellular organelles and proteins to maintain cell homeostasis. Alterations in autophagy occur in various diseases; however, the role of autophagy in gestational diabetes mellitus (GDM) is unknown. In the present study, we characterized the roles and functions of autophagy in GDM patient samples and extravillous trophoblasts cultured with glucose. We found significantly enhanced autophagy in GDM patients. Moreover, high glucose levels enhanced autophagy and cell apoptosis, reducing proliferation and invasion, and these effects were ameliorated through knockdown of ATG5. Genome-wide 5-hydroxymethylcytosine data analysis further revealed the epigenomic regulatory circuitry underlying the induced autophagy and apoptosis in GDM and preeclampsia. Finally, RNA sequencing was performed to identify gene expression changes and critical signaling pathways after silencing of ATG5. Our study has demonstrated the substantial functions of autophagy in GDM and provides potential therapeutic targets for the treatment of GDM patients.

Role of Plasminogen Activator Inhibitor Type 1 in Pathologies of Female Reproductive Diseases

Normal pregnancy is a state of hypercoagulability with diminishing fibrinolytic activity, which is mainly caused by an increase of plasminogen activator inhibitor type 1 (PAI-1). PAI-1 is the main inhibitor of plasminogen activators, including tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA). In human placentas, PAI-1 is expressed in extravillous interstitial trophoblasts and vascular trophoblasts. During implantation and placentation, PAI-1 is responsible for inhibiting extra cellular matrix (ECM) degradation, thereby causing an inhibition of trophoblasts invasion. In the present study, we have reviewed the literature of various reproductive diseases where PAI-1 plays a role. PAI-1 levels are increased in patients with recurrent pregnancy losses (RPL), preeclampsia, intrauterine growth restriction (IUGR), gestational diabetes mellitus (GDM) in the previous pregnancy, endometriosis and polycystic ovary syndrome (PCOS). In general, an increased expression of PAI-1 in the blood is associated with an increased risk for infertility and a worse pregnancy outcome. GDM and PCOS are related to the genetic role of the 4G/5G polymorphism of PAI-1. This review provides an overview of the current knowledge of the role of PAI-1 in reproductive diseases. PAI-1 represents a promising monitoring biomarker for reproductive diseases and may be a treatment target in the near future.

Metabolic abnormalities and obesity's impact on the risk for developing preeclampsia

Preeclampsia (PE), a hypertensive disorder of pregnancy, is increasing as a major contributor to perinatal and long-term morbidity of mother and offspring. PE is thought to originate from ischemic insults in the placenta driving the release of prohypertensive anti-angiogenic [soluble fms-like tyrosine kinase-1 (sFlt-1)] and proinflammatory [tumor necrosis factor-α (TNF-α)] factors into the maternal circulation. Whereas the increased incidence of PE is hypothesized to be largely due to the obesity pandemic, the mechanisms whereby obesity increases this risk are unknown. The maternal endothelium is targeted by placental and adipose tissue-derived factors like sFlt-1 and TNF-α that promote hypertension during pregnancy, resulting in vascular dysfunction and hypertension. Interestingly, not all obese pregnant women develop PE. Data suggest that obese pregnant women with the greatest metabolic abnormalities have the highest incidence of PE. Identifying obesity-related mechanisms driving hypertension in some obese pregnant women and pathways that protect normotensive obese pregnant women, may uncover novel protocols to treat PE. Metabolic abnormalities, such as increased circulating leptin, glucose, insulin, and lipids, are likely to increase the risk for PE in obese women. It is not only important to understand whether each of these metabolic factors contribute to the increased risk for PE in obesity, but also their cumulative effects. This is particularly relevant to obese pregnant women with gestational diabetes mellitus (GDM) where all of these factors are increased and the risk for PE is highest. It is speculated that these factors potentiate the anti-angiogenic and proinflammatory mechanisms of placental ischemia-induced vascular dysfunction thereby contributing to the increasing incidence of PE.

Low-level laser irradiation effect on endothelial cells under conditions of hyperglycemia

Diabetes mellitus is considered to be a very serious lifestyle disease leading to cardiovascular complications and impaired wound healing observed in the diabetic foot syndrome. Chronic hyperglycemia is the source of the endothelial activation. The inflammatory process in diabetes is associated with the secretion of inflammatory cytokines by endothelial cells, e.g., tumor necrosis factor-alpha (TNF-α) and interleukin 6 (IL-6). The method of phototherapy using laser beam of low power (LLLT-low-level laser therapy) effectively supports the conventional treatment of diabetic vascular complications such as diabetic foot syndrome. The aim of our study was to evaluate the effect of low-power laser irradiation at two wavelengths (635 and 830 nm) on the secretion of inflammatory factors (TNF-α and IL-6) by the endothelial cell culture-HUVEC line (human umbilical vein endothelial cell)-under conditions of hyperglycemia. It is considered that adverse effects of hyperglycemia on vascular endothelial cells may be corrected by the action of LLLT, especially with the wavelength of 830 nm. It leads to the reduction of TNF-α concentration in the supernatant and enhancement of cell proliferation. Endothelial cells play an important role in the pathogenesis of diabetes; however, a small number of studies evaluate an impact of LLLT on these cells under conditions of hyperglycemia. Further work on this subject is warranted.

Decoding the oxidative stress hypothesis in diabetic embryopathy through proapoptotic kinase signaling

Maternal diabetes-induced birth defects occur in 6-10% of babies born to mothers with pregestational diabetes, representing a significant maternal-fetal health problem. Currently, these congenital malformations represent a significant maternal-fetal medicine issue, but are likely to create an even greater public health threat as 3 million women of reproductive age (19-44 years) have diabetes in the United States alone, and this number is expected to double by 2030. Neural tube defects (NTDs) and congenital heart defects are the most common types of birth defects associated with maternal diabetes. Animal studies have revealed that embryos under hyperglycemic conditions exhibit high levels of oxidative stress resulting from enhanced production of reactive oxygen species and impaired antioxidant capability. Oxidative stress activates a set of proapoptotic kinase signaling intermediates leading to abnormal cell death in the embryonic neural tube, which causes NTD formation. Work in animal models also has revealed that maternal diabetes triggers a series of signaling intermediates: protein kinase C (PKC) isoforms, PKCα, βII and δ; apoptosis signal-regulating kinase 1; c-Jun-N-terminal kinase (JNK)1/2; caspase; and apoptosis. Specifically, maternal diabetes in rodent models activates the proapoptotic unfolded protein response and endoplasmic reticulum (ER) stress. A reciprocal causation between JNK1/2 activation and ER stress exists in diabetic embryopathy. Molecular studies further demonstrate that deletion of the genes for Prkc, Ask1, Jnk1, or Jnk2 abolishes maternal diabetes-induced neural progenitor apoptosis and ameliorates NTD formation. Similar preventive effects are also observed when apoptosis signal-regulating kinase 1, JNK1/2, or ER stress is inhibited. Cell membrane stabilizers and antioxidant supplements are also effective in prevention of diabetes-induced birth defects. Mechanistic studies have revealed important insights into our understanding the cause of diabetic embryopathy and have provided a basis for future interventions against birth defects or other pregnancy complications associated with maternal diabetes. The knowledge of a molecular pathway map identified in animal studies has created unique opportunities to identify molecular targets for therapeutic intervention.

Hyperglycemia down-regulates cGMP-dependent protein kinase I expression in first trimester cytotrophoblast cells

Diabetes in pregnancy is associated with microvascular complications and a higher incidence of preeclampsia. The regulatory signaling pathways involving nitric oxide, cGMP, and cGMP-dependent protein kinase (PKG) have been shown to be down-regulated under diabetic conditions and contribute to the pathogenesis of vascular complications in diabetes. The present study was undertaken to investigate how high glucose concentrations regulate PKG expression in cytotrophoblast cells (CTBs). Human CTBs (Sw. 71) were treated with 45, 135, 225, 495, or 945 mg/dL glucose for 48 h. Some cells were pretreated with a p38 inhibitor (10 μM SB203580) or 10 μM rosiglitazone. After treatment, the cell lysates were subjected to measure the expression of protein kinase G1α (PKG1α), protein kinase G1β (PKG1β), soluble guanylate cyclase 1α (sGC1α), and soluble guanylate cyclase 1 β (sGC1β) by Western blot. Statistical comparisons were performed using analysis of variance with Duncan's post hoc test. The expressions of PKG1α, PKG1β, sGC1α, and sGC1β were significantly down-regulated (p < 0.05) in CTBs treated with >135 mg/dL glucose compared to basal (45 mg/dL). The hyperglycemia-induced down-regulation of cGMP and cGMP-dependent PKG were attenuated by the SB203580 or rosiglitazone pretreatment. Exposure of CTBs to excess glucose down-regulates cGMP and cGMP-dependent PKG, contributing to the development of vascular complications in diabetic mothers during pregnancy. The attenuation of hyperglycemia-induced down-regulation of PKG proteins by SB203580 or rosiglitazone pretreatment further suggests the involvement of stress signaling mechanisms in this process.

Pre-eclampsia has an adverse impact on maternal and fetal health

Pre-eclampsia (preE) is a multifaceted complication found uniquely in the pregnant patient and one that has puzzled scientists for years. PreE is not a single disorder, but a complex syndrome that is produced by various pathophysiological triggers and mechanisms affecting about 5% of obstetrical patients. PreE is a major cause of premature delivery and maternal and fetal morbidity and mortality. PreE is characterized by de novo development of hypertension and proteinuria after 20 weeks of gestation and affects nearly every organ system, with the most severe consequences being eclampsia, pulmonary edema, intrauterine growth restriction, and thrombocytopenia. PreE alters the intrauterine environment by modulating the pattern of hormonal signals and activating the detrimental cellular signaling that has been transported to the fetus. The fetus has to adapt to this intrauterine environment with detrimental signals. The adaptive changes increase the risk of disease later in life. This review defines the predisposition and causes of preE and the cellular signaling detrimental to maternal health during preE. Moreover, the risk factors for diseases that are transmitted to the offspring have been addressed in this review. The detrimental signaling molecules that have been overexpressed in preE patients raises the possibility that those signals could be therapeutically blocked one day.

Glucose and metformin modulate human first trimester trophoblast function: a model and potential therapy for diabetes-associated uteroplacental insufficiency

PROBLEM

Diabetes confers an increased risk of preeclampsia, but its pathogenic role in preeclampsia is poorly understood. The objective of this study was to elucidate the effects of excess glucose on trophoblast function and whether any changes could be reversed by metformin.

METHOD OF STUDY

The human first trimester trophoblast cell line (Sw.71) was treated with glucose at 5, 10, 25, and 50 mm, in the presence and absence of metformin. Trophoblast migration was quantified and supernatant cytokine, chemokine, and angiogenic factors measured.

RESULTS

Increasing concentrations of glucose significantly increased trophoblast secretion of the inflammatory cytokines/chemokines: IL-1β, IL-6, IL-8, GRO-α, RANTES, and G-CSF; significantly increased trophoblast secretion of the anti-angiogenic factors sFlt-1 and sEndoglin; and significantly decreased trophoblast migration. Excess glucose-induced trophoblast IL-1β production was inhibited by disabling the Nalp3/ASC inflammasome. Metformin partially reduced the glucose-induced inflammatory response, but had no effect on the anti-angiogenic or antimigratory response.

CONCLUSION

Excess glucose induced a pro-inflammatory, anti-angiogenic, and antimigratory state in first trimester trophoblast cells. Glucose-induced trophoblast IL-1β secretion was mediated by the inflammasome. Glucose-induced inflammation was partially reversed by metformin. These findings demonstrate the pleiotropic effects of hyperglycaemia on the trophoblast, providing potential explanations for the strong link between diabetes and preeclampsia.

Levels of microRNA-181b and plasminogen activator inhibitor-1 are associated with hypertensive disorders complicating pregnancy

The aim of the present study was to explore the association between the expression of microRNA (miRNA)-181b and plasminogen activator inhibitor-1 (PAI-1) in the placental tissue of pregnant females with a hypertensive disorder complicating pregnancy (HDCP). Placental tissue samples were obtained from 48 patients with HDCP and 40 females with a normal pregnancy. The levels of miRNA-181b and PAI-1 mRNA were determined by the reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The expression of PAI-1 protein was analyzed by western blotting. Vascular smooth muscle cells (VSMCs) were transfected with the pEGP-miRNA-181b plasmid using Lipofectamine^® 2000. Transfection efficiency was confirmed by immunohistochemical analysis. The levels of miRNA-181b in the placental tissue of patients with HDCP were lower than those in the control group, whereas the levels of PAI-1 mRNA in the placental tissue of patients with HDCP were higher than those in the control group. The expression of the PAI-1 protein in the HDCP group was higher than that in the control group. Following transfection of VSMCs with plasmid pGCMV/EGFP/miRNA-181b, the levels of PAI-1 mRNA were reduced while the levels of miRNA-181 were upregulated. Furthermore, the expression levels of PAI-1 protein were lower than those in the control group. The levels of miRNA-181b and PAI-1 mRNA were strongly associated with HDCP. Thus, miRNA-181b may play an important role in the regulation of PAI-1. PAI-1 and miRNA-181b may be novel biomarkers to be used in HDCP therapy.