Molecular biomarkers for gestational diabetes mellitus and postpartum diabetes

Potential causal associations between perfluoroalkyl substances exposure and adverse pregnancy outcomes: A bidirectional two-sample mendelian randomization study

Maternal exposure to per- and polyfluoroalkyl substances (PFASs) has been linked to adverse pregnancy outcomes (APOs). Nonetheless, the genetic causality underlying this association remains unknown. This research employed a bidirectional two-sample Mendelian randomization (MR) to investigate the potential causal associations between PFASs exposure and APOs risk. PFASs data were sourced from the GWAS Catalog, and APOs data were retrieved from the FinnGen consortium. Causal estimation primarily employed inverse variance weighting, with Cochran's Q test for instrumental variable heterogeneity, and MR-Egger, MR-PRESSO, and leave-one-out tests for sensitivity analyses. The possibility of reverse causality was investigated through reverse MR. MR evidence revealed a notable correlation between perfluorooctanoic acid (PFOA) and abruptio placentae (OR=1.498, P=0.026), as well as short gestation and low birth weight (OR=1.720, P=0.013). Exposure to perfluorooctanesulfonic acid (PFOS) increased the risk of preeclampsia or eclampsia (OR=1.128, P=0.030) and gestational hypertension (OR=1.076, P=0.049), but decreased the risk of premature rupture of membranes (OR=0.916, P=0.033). The results obtained were consistent across various sensitivity analyses. Reverse MR results was negative. These findings may provide a reference for prevention strategies and intervention measures for PFASs exposure and APOs, and provide a framework for studying the causal effects of environmental pollutant exposure and human diseases.

Association of maternal blood metabolomics and gestational diabetes mellitus risk: a systematic review and meta-analysis

Gestational diabetes mellitus (GDM) is a common complication of pregnancy that has short- and long-term adverse effects. Therefore, further exploration of the pathophysiology of GDM and related biomarkers is important. In this study, we performed a systematic review and meta-analysis to investigate the associations between metabolites in blood detected via metabolomics techniques and the risk of GDM and to identify possible biomarkers for predicting the occurrence of GDM. We retrieved case‒control and cohort studies of metabolomics and GDM published in PubMed, Embase, and Web of Science through March 29, 2024; extracted metabolite concentrations, odds ratios (ORs), or relative risks (RRs); and evaluated the integrated results with metabolites per-SD risk estimates and 95% CIs for GDM. We estimated the results via the random effects model and the inverse variance method. Our study is registered in PROSPERO (CRD42024539435). We included a total of 28 case‒control and cohort studies, including 17,370 subjects (4,372 GDM patients and 12,998 non-GDM subjects), and meta-analyzed 67 metabolites. Twenty-five of these metabolites were associated with GDM risk. Some amino acids (isoleucine, leucine, valine, alanine, aspartate, etc.), lipids (C16:0, C18:1n-9, C18:1n-7, lysophosphatidylcholine (LPC) (16:0), LPC (18:0), and palmitoylcarnitine), and carbohydrates and energy metabolites (glucose, pyruvate, lactate, 2-hydroxybutyrate, 3-hydroxybutyrate) were discovered to be associated with increased GDM risk (hazard ratio 1.06-2.77). Glutamine, histidine, C14:0, and sphingomyelin (SM) (34:1) were associated with lower GDM risk (hazard ratio 0.75-0.84). These findings suggest that these metabolites may play essential roles in GDM progression, and serve as biomarkers, contributing to the early diagnosis and prediction of GDM.

Nonlinear association between alanine aminotransferase to high-density lipoprotein cholesterol ratio and risk of gestational diabetes mellitus

Previous studies have indicated a potential association between the alanine aminotransferase to high-density lipoprotein cholesterol (ALT/HDL-C) ratio and the risk of Type 2 Diabetes Mellitus, but its relation with gestational diabetes mellitus (GDM) remains uncertain. This study aims to investigate the correlation between the ALT/HDL-C ratio in early pregnancy and the risk of GDM. This study is a secondary analysis based on an open-source cohort study. A total of 590 single pregnant women attending two hospitals in Korea up to 14 weeks gestation were included between November 2014 and July 2016. Logistic regression analysis, subgroup analysis, and smooth curve fitting were employed to explore the association between the ALT/HDL-C ratio and GDM risk. The predictive capability of the ALT/HDL-C ratio for GDM was assessed using ROC curve analysis. The average age of participants was 32.06 ± 3.80 years, with a GDM incidence rate of 6.27%. Multifactorial logistic regression analysis revealed that the serum ALT/HDL-C ratio is an independent influencing factor for GDM (OR = 1.08, 95% CI: 1.02-1.16). Furthermore, a non-linear relationship between the ALT/HDL-C ratio and GDM risk was observed, with a turning point at 5.51. The effect size (OR) on the left and right sides of the turning point were 0.75 (95% CI: 0.37-1.59) and 1.55 (95% CI: 1.18-2.00), respectively. Additionally, when combined with age, pre-pregnancy body mass index, parity, and insulin resistance index in a prediction model for GDM, the ALT/HDL-C ratio demonstrated improved sensitivity of prediction by reaching up to 67.6%, specificity of prediction by reaching up to 87.3%, and an area under curve value of 0.819 (95%CI: 0.743-0.894). In early pregnancy, the serum ALT/HDL-C ratio shows a positive correlation with maternal risk in a nonlinear manner. The combination of ALT/HDL-C ratio with maternal characteristics and metabolic indicators provides good predictive value for GDM. This study may facilitate optimization of GDM prevention in pregnant women and enable timely and effective intervention to enhance their prognosis.

The role of microRNAs in pregnancies complicated by maternal diabetes

With the global prevalence of diabetes increasing, more people of reproductive age are experiencing hyperglycaemic pregnancies. Maternal Type 1 (T1DM) or Type 2 (T2DM) diabetes mellitus, and gestational diabetes mellitus (GDM) are associated with maternal cardiovascular and metabolic complications. Pregnancies complicated by maternal diabetes also increase the risk of short- and long-term health complications for the offspring, including altered fetal growth and the onset of T2DM and cardiometabolic diseases throughout life. Despite advanced methods for improving maternal glucose control, the prevalence of adverse maternal and offspring outcomes associated with maternal diabetes remains high. The placenta is a key organ at the maternal-fetal interface that regulates fetal growth and development. In pregnancies complicated by maternal diabetes, altered placental development and function has been linked to adverse outcomes in both mother and fetus. Emerging evidence suggests that microRNAs (miRNAs) are key molecules involved in mediating these changes. In this review, we describe the role of miRNAs in normal pregnancy and discuss how miRNA dysregulation in the placenta and maternal circulation is associated with suboptimal placental development and pregnancy outcomes in individuals with maternal diabetes. We also discuss evidence demonstrating that miRNA dysregulation may affect the long-term health of mothers and their offspring. As such, miRNAs are potential candidates as biomarkers and therapeutic targets in diabetic pregnancies at risk of adverse outcomes.

G protein-coupled receptor 1 participating in the mechanism of mediating gestational diabetes mellitus by phosphorylating the AKT pathway

Gestational diabetes mellitus (GDM) is a metabolic disease that occurs during pregnancy. Herein, we investigate G protein-coupled receptor 1 (GPR1) in mediating GDM through the phosphorylation of serine/threonine kinase (AKT) pathway. Thirty pregnant SD rats were grouped into: normal pregnancy control group (NC), GDM model group, and GDM model + high-dose GPR1 antagonist treatment (GDM + Ari) group. GDM model was established, and the GDM + Ari group adopted GPR1 antagonist aripiprazole. The blood glucose level, insulin level, and insulin resistance (IR) were detected. The expression and phosphorylation of GPR1, AKT, and extracellular signal-regulated kinase (ERK) in placental tissue were detected using reverse transcription-polymerase chain reaction (RT-PCR) and western blotting (WB). The serum insulin concentration, glucose concentration, and glycated hemoglobin concentration during pregnancy in GDM group SD rats were significantly higher than those in the NC group (P < 0.05). The expression and phosphorylation levels of GPR1, AKT, and ERK in the placental tissue of SD pregnant rats in the GDM group were significantly lower than those in the NC group. Furthermore, compared with the GDM group, the expression of GPR1, AKT, and ERK in placental tissue was significantly reduced in the GDM + Ari group, while simultaneously enhancing the blood glucose level and IR level. In addition, the survival number, body weight, and malformation rate of the offspring of the GDM + Ari group were significantly improved, and there was no significant effect on the number of offspring. The expressions of GPR1, AKT, and ERK in placental tissue exhibited a significant decrease, while the glucose level and IR were observed to increase in the GDM + Ari group. Enhancing the expression of GPR1 may activate AKT phosphorylation to alleviate GDM. GPR1 could potentially serve as a novel target for diabetes treatment, offering new insights into managing GDM.

Longitudinal observation of tRNA-derived fragments profiles in gestational diabetes mellitus and its diagnostic value

BACKGROUND

Gestational Diabetes Mellitus (GDM) poses significant risks to maternal and fetal health. Current diagnostic methods based on glucose tolerance tests have limitations for early detection. tRNA-derived small RNAs (tsRNAs) have emerged as potential molecular regulators in various diseases, including metabolic disorders. However, the diagnostic value of tsRNAs in plasma for early GDM or postpartum remains unclear.

METHODS

This longitudinal study profiled the expression of tsRNAs across different gestational stages and postpartum in women with GDM (n = 40) and healthy control gestational women (HCs, n = 40). High-throughput small RNA sequencing identified candidate tsRNAs, which were then validated and correlated with clinical biochemical markers such as fasting blood glucose (FBG), HOMA-IR, and GHbA1c.

RESULTS

tRF-1:32-Val-AAC-1-M6, tRF-1:31-Glu-CTC-1-M2, and tRF-1:30-Gly-CCC-1-M4 were consistently upregulated in the GDM group compared to HCs during the second trimester (p < 0.05). Only tRF-1:31-Glu-CTC-1-M2 was highly expressed during the first trimester, and tRF-1:30-Gly-CCC-1-M4 increased during postpartum. tRF-1:31-Glu-CTC-1-M2 showed a significant correlation with FBG levels in the first trimester (R = 0.317, p = 0.047). The expression of tRF-1:30-Gly-CCC-1-M4 was significantly correlated with HOMA-IR (r = 0.65, p < 0.001) and GHBA1c (r = 0.33, p = 0.037) during postpartum. A joint diagnostic model incorporating tsRNAs expression and clinical markers demonstrated enhanced predictive power for GDM (ROC AUC = 0.768).

CONCLUSION

Our results revealed distinct expression patterns of specific tsRNAs in GDM, showcasing their correlation with key metabolic parameters. This underscores their promising role as biomarkers for early prediction and diagnosis of GDM. The integration of tRFs into a composite biomarker panel holds the potential to improve clinical outcomes by enabling personalized risk assessment and targeted interventions.

Biochemical Markers in the Prediction of Pregnancy Outcome in Gestational Diabetes Mellitus

Background and Objectives: Gestational diabetes mellitus (GDM) may impact both maternal and fetal/neonatal health. The identification of prognostic indicators for GDM may improve risk assessment and selection of patient for intensive monitoring. The aim of this study was to find potential predictors of adverse pregnancy outcome in GDM and normoglycemic patients by comparing the levels of different biochemical parameters and the values of blood cell count (BCC) between GDM and normoglycemic patients and between patients with adverse and good outcome. Materials and Methods: Prospective clinical study included 49 patients with GDM (study group) and 44 healthy pregnant women (control group) who underwent oral glucose tolerance test (OGTT) at gestational age of 24-28 weeks. At the time of OGTT peripheral blood was taken for the determination of glucose levels, insulin, glycated hemoglobin, lipid status, homeostatic model assessment, BCC, iron and zinc metabolism, liver function, kidney function and inflammatory status. Each group was divided into two subgroups-normal and poor pregnancy outcome. Results: Higher RBC, hemoglobin concentration, hematocrit value, fasting glucose, uric acid and fibrinogen were found in GDM patients compared to control group. In GDM patients with poor pregnancy outcome values of fibrinogen, ALT, sedimentation rate, granulocyte and total leukocyte counts were elevated, while the serum level of zinc was significantly lower. Higher level of fibrinogen was found in normoglycemic patients with adverse pregnancy outcomes. ROC curve was constructed in order to assess fibrinogen's biomarker potential. The established AUC value for diagnostic ROC was 0.816 (p < 0.001, 95% CI 0.691-0.941), while the AUC value for assessing fibrinogen's potential to predict poor pregnancy outcome in GDM was 0.751 (p = 0.0096, 95% CI 0.561-0.941). Conclusions: The results of our study demonstrated that the best prognostic potential in GDM showed inflammation related parameters, identifying fibrinogen as a parameter with both diagnostic and prognostic ability.

METTL3 regulates glucose transporter expression in placenta exposed to hyperglycemia through the mTOR signaling pathway

BACKGROUND

Alterations in the placental expression of glucose transporters (GLUTs), the crucial maternal-fetal nutrient transporters, have been found in women with hyperglycemia in pregnancy (HIP). However, there is still uncertainty about the underlying effect of the high-glucose environment on placental GLUTs expression in HIP.

METHODS

We quantitatively evaluated the activity of mammalian target of rapamycin (mTOR) and expression of GLUTs (GLUT1, GLUT3, and GLUT4) in the placenta of women with normal pregnancies (CTRL, n = 12) and pregnant women complicated with poorly controlled type 2 diabetes mellitus (T2DM, n = 12) by immunohistochemistry. In addition, BeWo cells were treated with different glucose concentrations to verify the regulation of hyperglycemia. Then, changes in the expression of GLUTs following the activation or suppression of the mTOR pathway were also assessed using MHY1485/rapamycin (RAPA) treatment or small interfering RNA (siRNA)-mediated silencing approaches. Moreover, we further explored the alteration and potential upstream regulatory role of methyltransferase-like 3 (METTL3) when exposed to hyperglycemia.

RESULTS

mTOR, phosphorylated mTOR (p-mTOR), and GLUT1 protein levels were upregulated in the placenta of women with T2DM compared with those CTRL. In BeWo cells, mTOR activity increased with increasing glucose concentration, and the expression of GLUT1, GLUT3, and GLUT4 as well as GLUT1 cell membrane translocation were upregulated by hyperglycemia to varying degrees. Both the drug-mediated and genetic depletion of mTOR signaling in BeWo cells suppressed GLUTs expression, whereas MHY1485-induced mTOR activation upregulated GLUTs expression. Additionally, high glucose levels upregulated METTL3 expression and nuclear translocation, and decreasing METTL3 levels suppressed GLUTs expression and mTOR activity and vice versa . Furthermore, in METTL3 knockdown BeWo cells, the inhibitory effect on GLUTs expression was eliminated by activating the mTOR signaling pathway using MHY1485.

CONCLUSION

High-glucose environment-induced upregulation of METTL3 in trophoblasts regulates the expression of GLUTs through mTOR signaling, contributing to disordered nutrient transport in women with HIP.

Using metabolomics and proteomics to identify the potential urine biomarkers for prediction and diagnosis of gestational diabetes

Gestational diabetes mellitus (GDM) is one of the most common metabolic complications during pregnancy, threatening both maternal and fetal health. Prediction and diagnosis of GDM is not unified. Finding effective biomarkers for GDM is particularly important for achieving early prediction, accurate diagnosis and timely intervention. Urine, due to its accessibility in large quantities, noninvasive collection and easy preparation, has become a good sample for biomarker identification. In recent years, a number of studies using metabolomics and proteomics approaches have identified differential expressed urine metabolites and proteins in GDM patients. In this review, we summarized these potential urine biomarkers for GDM prediction and diagnosis and elucidated their role in development of GDM.

Effects of dietary intervention combined with insulin aspart on serum nesfatin-1 and CTRP12 levels and pregnancy outcomes in pregnant women with gestational diabetes mellitus

To analyze the effects of dietary intervention combined with insulin aspart on the serum levels of nesfatin-1, C1q/TNF related protein-12 (CTRP12), and pregnancy outcomes in pregnant women with gestational diabetes mellitus (GDM). In this retrospective cohort study, 513 women with GDM admitted to Tangshan Central Hospital (Tangshan, China) between January 2019 and December 2022 were selected and divided into an observation group (dietary intervention combined with insulin aspart therapy; n = 284) and a control group (insulin aspart therapy, n = 229). The general characteristics, clinical outcomes, serum nesfatin-1 and CTRP12 levels, 2-hour postprandial blood glucose levels, pregnancy outcomes, and perinatal outcomes of the 2 groups were compared. After treatment, the total effective rate in the observation group was significantly higher than that of the control group (97.54% vs 86.03%, respectively; P < .001). Compared with the pretreatment levels, nesfatin-1 and CTRP12 levels were decreased in both groups; nesfatin-1 and CTRP12 levels in the observation group were significantly higher than those in the control group. After treatment, the preprandial and 2-hour postprandial blood glucose levels in the observation group were significantly lower than those in the control group. Compared with the control group, the observation group had significantly fewer cesarean sections, and a significantly lower incidence of postpartum hemorrhage, premature rupture of membranes, and other adverse pregnancy outcomes. After treatment, the risks of preterm birth, macrosomia, fetal distress, neonatal asphyxia, neonatal hypoglycemia, and other adverse perinatal outcomes were significantly lower in the observation group than in the control group. In pregnant women with GDM, dietary intervention combined with insulin aspart can improve clinical outcomes; reduce nesfatin-1, CTRP12, and blood glucose levels; and reduce the incidence of adverse pregnancy outcomes.

Molecular pathways and nutrigenomic review of insulin resistance development in gestational diabetes mellitus

Gestational diabetes mellitus is a condition marked by raised blood sugar levels and insulin resistance that usually occurs during the second or third trimester of pregnancy. According to the World Health Organization, hyperglycemia affects 16.9% of pregnancies worldwide. Dietary changes are the primarily alternative treatment for gestational diabetes mellitus. This paper aims to perform an exhaustive overview of the interaction between diet, gene expression, and the metabolic pathways related to insulin resistance. The intake of foods rich in carbohydrates can influence the gene expression of glycolysis, as well as foods rich in fat, can disrupt the beta-oxidation and ketogenesis pathways. Furthermore, vitamins and minerals are related to inflammatory processes regulated by the TLR4/NF-κB and one carbon metabolic pathways. We indicate that diet regulated gene expression of PPARα, NOS, CREB3L3, IRS, and CPT I, altering cellular physiological mechanisms and thus increasing or decreasing the risk of gestational diabetes. The alteration of gene expression can cause inflammation, inhibition of fatty acid transport, or on the contrary help in the modulation of ketogenesis, improve insulin sensitivity, attenuate the effects of glucotoxicity, and others. Therefore, it is critical to comprehend the metabolic changes of pregnant women with gestational diabetes mellitus, to determine nutrients that help in the prevention and treatment of insulin resistance and its long-term consequences.

Hesperidin inhibits methylation and autophagy in LPS and high glucose-induced human villous trophoblasts

INTRODUCTION

Gestational diabetes mellitus (GDM) is the first occurrence of diabetes due to abnormal maternal sugar metabolism after pregnancy, which may lead to adverse pregnancy outcomes. Hesperidin is known to decrease in the cord blood of GDM with obesity, but its role is unknown. This study aims to explore the potential function of hesperidin in GDM with obesity to develop new therapeutic ideas.

METHODS

Peripheral blood and placental tissues from GDM and GDM with obesity patients were collected to isolate human villous trophoblasts and detection. Bioinformatics was used to analyze the differential methylation genes between GDM and GDM with obesity. Immunofluorescence was applied for the detection of CK7 expression. Cells vitality was detected by CCK8 and transwell. Molecular docking was applied to predict the binding of hesperidin and ATG7 protein. Inflammation and m6A levels was analyzed by ELISA. ATG7, LC3, TLR4 and P62 proteins was analyzed by Western blot.

RESULTS

The methylation of ATG7 gene was up-regulated in GDM with obesity compared with GDM. The m6A and autophagy proteins levels in GDM with obesity were higher than that in GDM. LPS with 2.5-25 mM glucose induced the increase of autophagy proteins, inflammation and m6A levels in human villous trophoblasts. Hesperidin formed hydrogen bonds and hydrophobic interactions with ATG7 proteins. Hesperidin (0.25 μM) inhibited the autophagy proteins and m6A level in LPS and 25 mM glucose-induced human villous trophoblasts.

DISCUSSION

GDM with obesity followed the increase of autophagy proteins and m6A levels. Hesperidin inhibited the autophagy proteins and m6A level in LPS and glucose-induced human villous trophoblasts.

Current Status and Prospects of the Single-Cell Sequencing Technologies for Revealing the Pathogenesis of Pregnancy-Associated Disorders

Single-cell RNA sequencing (scRNA-seq) is a method that focuses on the analysis of gene expression profile in individual cells. This method has been successfully applied to answer the challenging questions of the pathogenesis of multifactorial diseases and open up new possibilities in the prognosis and prevention of reproductive diseases. In this article, we have reviewed the application of scRNA-seq to the analysis of the various cell types and their gene expression changes in normal pregnancy and pregnancy complications. The main principle, advantages, and limitations of single-cell technologies and data analysis methods are described. We discuss the possibilities of using the scRNA-seq method for solving the fundamental and applied tasks related to various pregnancy-associated disorders. Finally, we provide an overview of the scRNA-seq findings for the common pregnancy-associated conditions, such as hyperglycemia in pregnancy, recurrent pregnancy loss, preterm labor, polycystic ovary syndrome, and pre-eclampsia.