Placental vascularization and apoptosis in Type-1 and gestational DM

Crosstalk between inflammasomes, inflammation, and Nrf2: Implications for gestational diabetes mellitus pathogenesis and therapeutics

The role of inflammasomes in gestational diabetes mellitus (GDM) has emerged as a critical area of research in recent years. Inflammasomes, key components of the innate immune system, are now recognized for their involvement in the pathogenesis of GDM. Activation of inflammasomes in response to various triggers during pregnancy can produce pro-inflammatory cytokines, such as interleukin-1β (IL-1β) and interleukin-18 (IL-18), contributing to systemic inflammation and insulin resistance. This dysregulation not only impacts maternal health but also poses significant risks to fetal development and long-term health outcomes. Understanding the intricate interplay between inflammasomes and GDM holds promise for developing novel therapeutic strategies and interventions to mitigate the adverse effects of this condition on both mothers and their offspring. Researchers have elucidated that targeting inflammasomes using anti-inflammatory drugs and compounds can effectively reduce inflammation in GDM. Furthermore, the addition of nuclear factor erythroid 2-related factor 2 (Nrf2) to this complex mechanism opens novel avenues for therapeutics. The antioxidant properties of Nrf2 may potentially suppress inflammasome activation in GDM. This comprehensive review investigates the intricate relationship between inflammasomes and GDM, emphasizing the pivotal role of inflammation in its pathogenesis. It also sheds light on potential therapeutic strategies targeting inflammasome activation and explores the role of Nrf2 in mitigating inflammation in GDM.

Early-life exposure to gestational diabetes mellitus predisposes offspring to pediatric nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) has emerged as the prevailing chronic liver disease in the pediatric population due to the global obesity pandemic. Evidence shows that prenatal and postnatal exposure to maternal abnormalities leads to a higher risk of pediatric NAFLD through persistent alterations in developmental programming. Gestational diabetes mellitus (GDM) is a hyperglycemic syndrome which has become the most prevalent complication in pregnant women. An increasing number of both epidemiologic investigations and animal model studies have validated adverse and long-term outcomes in offspring following GDM exposure in utero. Similarly, GDM is considered a crucial risk factor for pediatric NAFLD. This review aimed to summarize currently published studies concerning the inductive roles of GDM in offspring NAFLD development during childhood and adolescence. Dysregulations in hepatic lipid metabolism and gut microbiota in offspring, as well as dysfunctions in the placenta are potential factors in the pathogenesis of GDM-associated pediatric NAFLD. In addition, potentially effective interventions for GDM-associated offspring NAFLD are also discussed in this review. However, most of these therapeutic approaches still require further clinical research for validation.

Comparative study of microvascular structural changes in the gestational diabetic placenta

AIMS

Microvascular morphology and pathological changes in gestational diabetes mellitus (GDM) placentas and normal placentas were observed via vascular casting technology, electron microscopy, and pathological detection technology. Vascular structure and histological morphology changes in GDM placentas were examined to generate basic experimental data for the diagnosis and prognostic determination of GDM.

METHODS

This case-control study involving 60 placentas, 30 from healthy controls and 30 from patients with GDM. Differences in size, weight, volume, umbilical cord diameter, and gestational age were assessed. Histological changes in the placentas in the two groups were analyzed and compared. A placental vessel casting model was constructed using a self-setting dental powder technique, to compare the two groups. The placental cast microvessels of the two groups were compared using scanning electron microscopy.

RESULTS

There were no significant differences in maternal age or gestational age between the GDM group and the control group (p > .05). The size, weight, volume, and thickness of the placentas in the GDM group were significantly greater than those in the control group, as was umbilical cord diameter (p < .05). Immature villus, fibrinoid necrosis, calcification, and vascular thrombosis were significantly greater in the placental mass in the GDM group (p < .05). The terminal branches of the microvessels in diabetic placenta casts were sparse, with significantly fewer ends and lower villous volume (p < .05).

CONCLUSION

Gestational diabetes can cause gross and histological changes in the placenta, particularly placental microvascular changes.

Expression of Glucose Transporters 1 and 3 in the Placenta of Pregnant Women with Gestational Diabetes Mellitus

BACKGROUND

The annual prevalence of gestational diabetes mellitus-characterized by an increase in blood glucose in pregnant women-has been increasing worldwide. The goal of this study was to evaluate the expression of glucose transporter 1 (GLUT1) and glucose transporter 3 (GLUT3) in the placenta of women with gestational diabetes mellitus.

METHODS

Sixty-five placentas from women admitted to the King Saud University Medical City, Riyadh, Saudi Arabia, were analyzed; 34 and 31 placentas were from healthy pregnant women and women with gestational diabetes, respectively. The expressions of GLUT1 and GLUT3 were assessed using RT-PCR, Western blotting, and immunohistochemical methods. The degree of apoptosis in the placental villi was estimated via a TUNEL assay.

RESULTS

The results of the protein expression assays and immunohistochemical staining showed that the levels of GLUT1 and GLUT3 were significantly higher in the placentas of pregnant women with gestational diabetes than those in the placentas of healthy pregnant women. In addition, the findings showed an increase in apoptosis in the placenta of pregnant women with gestational diabetes compared to that in the placenta of healthy pregnant women. However, the results of gene expression assays showed no significant difference between the two groups.

CONCLUSIONS

Based on these results, we conclude that gestational diabetes mellitus leads to an increased incidence of apoptosis in the placental villi and alters the level of GLUT1 and GLUT3 protein expressions in the placenta of women with gestational diabetes. Understanding the conditions in which the fetus develops in the womb of a pregnant woman with gestational diabetes may help researchers understand the underlying causes of the development of chronic diseases later in life.

Obesity and gestational diabetes independently and collectively induce specific effects on placental structure, inflammation and endocrine function in a cohort of South African women

Maternal obesity and gestational diabetes mellitus (GDM) are associated with insulin resistance and health risks for mother and offspring. Obesity is also characterized by low-grade inflammation, which in turn, impacts insulin sensitivity. The placenta secretes inflammatory cytokines and hormones that influence maternal glucose and insulin handling. However, little is known about the effect of maternal obesity, GDM and their interaction, on placental morphology, hormones and inflammatory cytokines. In a South African cohort of non-obese and obese pregnant women with and without GDM, this study examined placental morphology using stereology, placental hormone and cytokine expression using real-time PCR, western blotting and immunohistochemistry, and circulating TNFα and IL-6 concentrations using ELISA. Placental expression of endocrine and growth factor genes was not altered by obesity or GDM. However, LEPTIN gene expression was diminished, syncytiotrophoblast TNFα immunostaining elevated and stromal and fetal vessel IL-6 staining reduced in the placenta of obese women in a manner that was partly influenced by GDM status. Placental TNFα protein abundance and maternal circulating TNFα concentrations were reduced in GDM. Both maternal obesity and, to a lesser extent, GDM were accompanied by specific changes in placental morphometry. Maternal blood pressure and weight gain and infant ponderal index were also modified by obesity and/or GDM. Thus, obesity and GDM have specific impacts on placental morphology and endocrine and inflammatory states that may relate to pregnancy outcomes. These findings may contribute to developing placenta-targeted treatments that improve mother and offspring outcomes, which is particularly relevant given increasing rates of obesity and GDM worldwide. KEY POINTS: Rates of maternal obesity and gestational diabetes (GDM) are increasing worldwide, including in low-middle income countries (LMIC). Despite this, much of the work in the field is conducted in higher-income countries. In a well-characterised cohort of South African women, this study shows that obesity and GDM have specific impacts on placental structure, hormone production and inflammatory profile. Moreover, such placental changes were associated with pregnancy and neonatal outcomes in women who were obese and/or with GDM. The identification of specific changes in the placenta may help in the design of diagnostic and therapeutic approaches to improve pregnancy and neonatal outcomes with particular significant benefit in LMICs.

The new landscape of differentially expression proteins in placenta tissues of gestational diabetes based on iTRAQ proteomics

INTRODUCTION

Gestational diabetes mellitus (GDM) refers to abnormal glucose tolerance that occurs or is firstly diagnosed during pregnancy. GDM is related to various adverse pregnancy outcomes, but GDM pathogeny has not been fully elucidated. Nevertheless, previous studies have observed that many proteins in the placentas of patients with GDM are dysregulated. The present study aimed to establish a novel differentially expressed protein (DEP) landscape of GDM and normal maternal placentas and to explore the possible connection between DEPs and GDM pathogenesis. This study provides new insights into the mechanism of GDM and should make an important contribution to the development of biomarkers.

METHODS

The morphological characteristics of the placenta were observed on 30 GDM and normal maternal placental tissues stained with haematoxylin and eosin. Isobaric tags for relative and absolute quantitation (iTRAQ) was used in the proteomics screening of the DEPs of the normal and GDM maternal placentas. Bioinformatics analysis was performed on the DEPs, and parallel reaction monitoring (PRM) was performed to verify the DEPs. Finally, the quantitative analysis of iTRAQ and PRM was verified by immunohistochemical assay.

RESULTS

A total of 68 DEPs in the GDM placenta were identified with iTRAQ proteomics experiment, comprising 21 up-regulated and 47 down-regulated DEPs. Bioinformatics analysis showed that the regulation of transport, catabolic process of non-coding RNA, cytoskeleton and cell binding were the most abundant Gene Ontology terms, and RNA degradation was an important pathway for significant enrichment. Protein-protein interaction network analysis showed that heterogeneous nuclear ribonucleoproteins A2/B1 (HNRNPA2B1), heterogeneous nuclear ribonucleoprotein A/B (HNRNPAB), heterogeneous nuclear ribonucleoprotein L (HNRNPL) and heterogeneous nuclear ribonucleoprotein A3 (HNRNPA3) were the cores of the up-regulated proteins. Band 3 anion transport protein (SLC4A1), spectrin beta chain erythrocytic (SPTB), ankyrin-1 (ANK1), spectrin beta chain non-erythrocytic 2 (SPTBN2), D-3-phosphoglycerate dehydrogenase (PHGDH) and exosome complex component RRP42 (EXOSC7) were the cores of the down-regulated proteins. These proteins are involved in the binding, splicing, processing, transport and degradation of RNA and in the formation and maintenance of the cytoskeleton. PRM verification results showed that seven proteins, namely, epiplakin (EPPK1), cold-inducible RNA-binding protein (CIRBP), HNRNPA2B1, HNRNPAB, HNRNPL, Ras-related protein Rab-21 (RAB21) and Ras-related protein Rab-3B (RAB3B), were up-regulated, whereas SPTB and SLC4A1 were down-regulated. The results of immunohistochemical assay also showed that the expression of five proteins, namely EPPK1, HNRNPA2B1, HNRNPAB, CIRBP and RAB21, were significantly higher in GDM placental tissues (P < 0.01). The GDM placentas showed changes in the morphological evaluation, including poor villous maturation, obvious increase in the number of syncytiotrophoblast nodules, thickening of the wall of dry villous arterioles with lumen stenosis, increased fibrinous exudation and excessive filling of villous interstitial vessels.

DISCUSSION

Differentially expressed proteins related to a variety of biological processes in the GDM placenta were found. Fourteen proteins, namely, HNRNPA2B1, HNRNPAB, HNRNPL, HNRNPA3, EPPK1, CIRBP, RAB21, RAB3B, SLC4A1, SPTB, ANK1, SPTBN2, PHGDH and EXOSC7, which were differentially expressed in the placenta, may play an important role in regulating the occurrence and development of gestational diabetes through multi-channel and multi-link regulation.

NLRP3 inflammasome activation in gestational diabetes mellitus placentas is associated with hydrogen sulfide synthetase deficiency

The placenta may play a key role in the activation of inflammation and initiation of insulin resistance (IR) during gestational diabetes mellitus (GDM) pathogenesis. Interleukin (IL)-1β and IL-18, regulated by NLR family pyrin domain containing-3 (NLRP3) inflammasome, are important inflammatory cytokines in the initiation of maternal IR during GDM. However, the mechanism responsible for the regulatory of NLRP3 inflammasome in placenta remains unknown. Hydrogen sulfide (H₂S) exerts anti-inflammatory function partially via suppressing the activation of the NLPR3 inflammasome. The present study aimed to investigate the role of NLRP3 inflammasome, H₂S synthetase cystathionine-γ-lyase (CSE) and cystathionine-β-synthetase (CBS) in placenta in the pathogenesis of GDM. Clinical placenta samples were collected from pregnant women with GDM (n=16) and healthy pregnant women at term (n=16). Western blot analysis was performed to detect the protein expression levels of NLRP3, cleaved caspase-1, CBS and CSE in the placenta samples. Pearson's correlation analysis was performed to assess the correlation between NLRP3 inflammasome and H₂S synthetase. Human placental cells were cultured and treated with different concentrations of NaHS (0, 10, 25 and 50 nmol/l) or L-cysteine (0, 0.25, 0.50 and 1.00 mmol/l). In addition, western blot analysis was performed to detect the protein expression levels of NLRP3 and cleaved caspase-1, while ELISA was performed to measure the production of IL-1β and IL-18 in the culture media. The results demonstrated that the expression levels of NLRP3 and cleaved caspase-1 increased, while the expression levels of CBS and CSE decreased in the placenta samples. In addition, the expression levels of NLRP3 and cleaved caspase-1 were inversely correlated with the expression levels of CBS and CSE. Notably, NaHS and L-cysteine significantly suppressed the expression levels of NLRP3 and cleaved caspase-1, and the production of IL-1 and IL-18 in human placental cells. Taken together, the results of the present study suggest that H₂S synthetase deficiency in placenta may contribute to excessive activation of NLRP3 inflammasome in GDM.

Maternal and neonatal outcomes in mothers with diabetes mellitus in qatari population

Abstract

Background

Diabetes Mellitus (DM) is a major cause of maternal, fetal, and neonatal morbidities. Our objective was to estimate the effect of both pre-pregnancy and gestational DM on the growth parameters of newborns in the Qatari population.

Methods

In this population-based cohort study, we compared the data of neonates born to Qatari women with both pre-pregnancy and gestational diabetes mellitus in 2017 with neonates of healthy non-diabetic Qatari women.

Results

Out of a total of 17020 live births in 2017, 5195 newborns were born to Qatari women. Of these, 1260 were born to women with GDM, 152 were born to women with pre-pregnancy DM and 3783 neonates were born to healthy non-diabetic (control) women. The prevalence of GDM in the Qatari population in 2017 was 24.25%. HbA1C% before delivery was significantly higher in women with pre-pregnancy DM (mean 6.19 ± 1.15) compared to those with GDM (mean 5.28 ± 0.43) (P <0.0001). The mean birth weight in grams was 3066.01 ± 603.42 in the control group compared to 3156.73 ± 577.88 in infants born to women with GDM and 3048.78 ± 677.98 in infants born to women with pre-pregnancy DM (P <0.0001). There was no statistically significant difference regarding the mean length (P= 0.080), head circumference (P= 0.514), and rate of major congenital malformations (P= 0.211). Macrosomia (Birth weight > 4000 gm) was observed in 2.7% of the control group compared to 4.8% in infants born to women with GDM, and 4.6% in infants born to women with pre-pregnancy DM (P= 0.001). Multivariate logistic regression analysis demonstrated that higher maternal age (adjusted OR 2.21, 95% CI 1.93, 2.52, P<0.0001), obesity before pregnancy (adjusted OR 1.71, 95% CI 1.30, 2.23, P<0.0001), type of delivery C-section (adjusted OR 1.25, 95% CI 1.09, 1.44, P=0.002), and body weight to gestational age LGA (adjusted OR 2.30, 95% CI 1.64, 2.34, P<0.0001) were significantly associated with increased risk of GDM.

Conclusion

Despite the multi-disciplinary antenatal diabetic care management, there is still an increased birth weight and an increased prevalence of macrosomia among the infants of diabetic mothers. More efforts should be addressed to improve the known modifiable factors such as women's adherence to the diabetic control program. Furthermore, pre-pregnancy BMI was found to be significantly associated with gestational DM, and this is a factor that can be addressed during pre-conceptional counseling.

Placental structural abnormalities in gestational diabetes and when they develop: A scoping review

Gestational diabetes mellitus (GDM) is defined as diabetes with onset or first recognition during gestation. It is a common complication of pregnancy that has become more prevalent over the past few decades. Abnormalities in fetal growth, including increased incidence of both large and small for gestational age babies, suggest placental dysfunction. The major goal of this scoping review is to determine what is known about abnormalities in placentas delivered from GDM pregnancies, and how early in gestation these abnormalities arise. A secondary goal is to review to what extent other selected factors, in particular obesity, have been found to influence or modify the reported effects of GDM on placental development, and whether these are considered in the study of GDM placentas. PubMed and Scopus databases were searched using the key terms: "gestational diabetes AND (woman OR human) AND placenta AND (ultrasound OR ultrastructure OR imaging OR histology OR pathology). Studies of gross morphology and histoarchitecture in placentas delivered from GDM pregnancies consistently report increased placental size, villous immaturity and a range of vascular lesions when compared to uncomplicated pregnancies. In contrast, a small number of ultrasound studies have examined placental development in GDM pregnancies in the second, and especially, the first trimester. Relatively few studies have analyzed interactions with maternal BMI, but these do suggest that it may play a role in placental abnormalities. Further examination of placental development early in pregnancy is needed to understand when it becomes disrupted in GDM, as a first step to identifying the underlying causes.

Lateral placentation and adverse perinatal outcomes

Lateral placentation may compromise placental perfusion, and we aimed to assess whether it impacts pregnancy outcomes. This single-center retrospective study included 1203 singleton pregnancies, categorized into two groups according to placental location. Women with lateral placenta had significantly higher risk of preterm birth <37 weeks (aOR 2.99) and <34 weeks (aOR 3.92), and gestational diabetes (aOR 2.72), compared to women with central placenta. Mean birth weight and small for gestational age (SGA) rates were similar between groups. Our findings suggest that lateral placenta may be associated with increased risk for preterm birth but not for SGA.