Serum and Amniotic Fluid Metabolic Profile Changes in Response to Gestational Diabetes Mellitus and the Association with Maternal–Fetal Outcomes

This study was designed to identify serum and amniotic fluid (AF) metabolic profile changes in response to gestational diabetes mellitus (GDM) and explore the association with maternal–fetal outcomes. We established the GDM rat models by combining a high-fat diet (HFD) with an injection of low-dose streptozotocin (STZ), detected the fasting plasma glucose (FPG) of pregnant rats in the second and third trimester, and collected AF and fetal rats by cesarean section on gestational day 19 (GD19), as well as measuring the weight and crown–rump length (CRL) of fetal rats. We applied liquid chromatography–tandem mass spectrometry (LC-MS/MS) for the untargeted metabolomics analyses of serum and AF samples and then explored their correlation with maternal–fetal outcomes via the co-occurrence network. The results showed that 91 and 68 metabolites were upregulated and 125 and 78 metabolites were downregulated in serum and AF samples exposed to GDM, respectively. In maternal serum, the obvious alterations emerged in lipids and lipid-like molecules, while there were great changes in carbohydrate and carbohydrate conjugates, followed by amino acids, peptides, and analogs in amniotic fluid. The altered pathways both in serum and AF samples were amino acid, lipid, nucleotide, and vitamin metabolism pathways. In response to GDM, changes in the steroid hormone metabolic pathway occurred in serum, and an altered carbohydrate metabolism pathway was found in AF samples. Among differential metabolites in two kinds of samples, there were 34 common biochemicals shared by serum and AF samples, and a mutual significant association existed. These shared differential metabolites were implicated in several metabolism pathways, including choline, tryptophan, histidine, and nicotinate and nicotinamide metabolism, and among them, N1-methyl-4-pyridone-3-carboxamide, 5’-methylthioadenosine, and kynurenic acid were significantly associated with both maternal FPG and fetal growth. In conclusion, serum and AF metabolic profiles were remarkably altered in response to GDM. N1-Methyl-4-pyridone-3-carboxamide, 5’-methylthioadenosine, and kynurenic acid have the potential to be taken as biomarkers for maternal–fetal health status of GDM. The common and inter-related differential metabolites both in the serum and AF implied the feasibility of predicting fetal health outcomes via detecting the metabolites in maternal serum exposed to GDM.

Efficacy of Low Molecular Heparin on Preeclampsia by Inhibiting Apoptosis of Trophoblasts via the p38MAPK Signaling Pathway

Objective. To explore the efficacy of low molecular heparin on preeclampsia by inhibiting apoptosis of trophoblasts via the p38MAPK signaling pathway. Methods. A preeclampsia rat model was established, and the effects of low molecular heparin on preeclampsia via the p38MAPK signaling pathway were analyzed based on intervention of the rats with different combinations of low molecular heparin and p38MAPK signaling pathway activator. Furthermore, a hypoxia/reoxygenation model of trophoblasts in vitro was established to explore the effects of low molecular heparin on trophoblasts via the p38MAPK signaling pathway. Results. After treatment with low molecular heparin, pregnant rats in the heparin group showed significantly decreased blood pressure, 24 h proteinuria, and p38MAPK protein levels in placenta tissues and decreased apoptosis rate of placenta tissue cells (all P < 0.05 ) and showed more fetal rats and lowered weight of them (both P < 0.05 ) but showed no significant change in the weight of placenta (all P > 0.05 ). Pregnant rats treated with low molecular heparin and p38MAPK activator showed significantly higher blood pressure, 24 h proteinuria, and p38MAPK protein levels in placenta tissues and apoptosis rate of placenta tissue cells than those of pregnant rats in the heparin group (all P < 0.05 ) and also showed less fetal rats and lighter fetal rats than those in the heparin group (both P < 0.05 ) but showed no difference with them in the weight of placenta ( P > 0.05 ). Further analysis revealed that low molecular heparin could protect the survival and migration of trophoblasts under hypoxia/reoxygenation conditions and reduce apoptosis of them (all P < 0.05 ). Conclusion. Low molecular heparin can alleviate preeclampsia by inhibiting the p38MAPK signaling pathway and can inhibit apoptosis of trophoblasts and promote proliferation and migration of them.

Prenatal Glucocorticoid Administration Accelerates Maturation in the Hepatocytes of Fetal Rats

Prenatal glucocorticoid (GC) is clinically administered to pregnant women at risk of preterm birth for maturation of the cardiopulmonary function. Preterm and low birth weight infants often experience liver dysfunction after birth because the liver is immature. However, the effects of prenatal GC administration on the liver remain unclear. We aimed to investigate the effects of prenatal GC administration regarding maturity of the liver in preterm rats. Dexamethasone (DEX) was administered to pregnant Wistar rats on gestational day 17 and 19 before cesarean section. Real time polymerase chain reaction (RT-PCR) was then used to analyze the mRNA levels (albumin, HNF4α, HGF, Thy-1, cyclin B, and CDK1) in the liver samples. Immunohistochemical staining and enzyme-linked immunosorbent assay (ELISA) were used to analyze protein production. Hepatocyte size enlarged because of growth and administration of prenatal DEX. Albumin, HNF4α, and hepatocyte growth factor (HGF) increased secondary to growth and administration of prenatal DEX. Cell cycle markers, cyclin B, and CDK1 gradually decreased during growth and by administration of DEX. These results suggest that prenatal GC administration achieves hepatocyte maturation via expression of HNF4α and HGF in premature fetuses.

Erratum: Romero-Lopez, M.d.M., et al. Lung Metabolomics Profiling of Congenital Diaphragmatic Hernia in Fetal Rats. Metabolites 2021, 11, 177

The authors wish to make the following corrections to this paper [...]

Gender difference in adrenal developmental toxicity induced by dexamethasone and its intrauterine programming mechanism

Background and Purpose: Dexamethasone is widely used in preterm labor and related diseases. However, prenatal dexamethasone exposure (PDE) can cause multi-organ developmental toxicities in offspring. Our previous study found the occurrence of fetal-originated diseases were associated with adrenal developmental programming alteration in offspring. Here, we investigated the effects of PDE on the adrenal function in offspring and its intrauterine programming mechanism. Experimental Approach: A rat model of PDE was established to observe the alteration of adrenal steroidogenesis in offspring. Further, we confirmed the gender difference of adrenal steroidogenesis and its molecular mechanism combined with in vivo and in vitro experiment. Key Results: PDE caused a decrease in adrenal steroidogenic function in fetal rats, but decreased in males and increased in females after birth. Meanwhile, the adrenal H3K14ac level and expression of 11β-hydroxysteroid dehydrogenase 2 (11β-HSD2) in PDE offspring were decreased in males and increased in females, suggesting 11β-HSD2 might mediate gender difference of adrenal function. We further confirmed dexamethasone inhibited the H3K14ac level and expression of 11β-HSD2 through GR/SP1/p300 pathway. After bilateral testectomy or ovariectomy in adult PDE offspring rats, adrenal 11β-HSD2 expression and steroidogenic function were both reduced. Using rat primary fetal adrenal cells, the differential expression in AR and ERβ were proved to involve in regulating the gender difference of 11β-HSD2 expression. Conclusion and Implications: This study demonstrated the gender difference in adrenal steroidogenic function of PDE offspring after birth, and elucidates a sex hormone receptor-dependent epigenetically regulating mechanism for adrenal 11β-HSD2 programming alteration.

Lung Metabolomics Profiling of Congenital Diaphragmatic Hernia in Fetal Rats

Congenital diaphragmatic hernia (CDH) is characterized by the herniation of abdominal contents into the thoracic cavity during the fetal period. This competition for fetal thoracic space results in lung hypoplasia and vascular maldevelopment that can generate severe pulmonary hypertension (PH). The detailed mechanisms of CDH pathogenesis are yet to be understood. Acknowledgment of the lung metabolism during the in-utero CDH development can help to discern the CDH pathophysiology changes. Timed-pregnant dams received nitrofen or vehicle (olive oil) on E9.5 day of gestation. All fetal lungs exposed to nitrofen or vehicle control were harvested at day E21.5 by C-section and processed for metabolomics analysis using nuclear magnetic resonance (NMR) spectroscopy. The three groups analyzed were nitrofen-CDH (NCDH), nitrofen-control (NC), and vehicle control (VC). A total of 64 metabolites were quantified and subjected to statistical analysis. The multivariate analysis identified forty-four metabolites that were statistically different between the three groups. The highest Variable importance in projection (VIP) score (>2) metabolites were lactate, glutamate, and adenosine 5′-triphosphate (ATP). Fetal CDH lungs have changes related to oxidative stress, nucleotide synthesis, amino acid metabolism, glycerophospholipid metabolism, and glucose metabolism. This work provides new insights into the molecular mechanisms behind the CDH pathophysiology and can explore potential novel treatment targets for CDH patients.

Transcriptional factor FoxM1-activated microRNA-335-3p maintains the self-renewal of neural stem cells by inhibiting p53 signaling pathway via Fmr1

Background New mechanistic insights into the self-renewal ability and multipotent properties of neural stem cells (NSCs) are currently under active investigation for potential use in the treatment of neurological diseases. In this study, NSCs were isolated from the forebrain of fetal rats and cultured to induce NSC differentiation, which was associated with low expression of the non-coding RNA microRNA-335-3p (miR-335-3p). Methods Loss- and gain-of-function experiments were performed in NSCs after induction of differentiation. Results Overexpression of miR-335-3p or FoxM1 and inhibition of the Fmr1 or p53 signaling pathways facilitated neurosphere formation, enhanced proliferation and cell cycle entry of NSCs, but restricted NSC differentiation. Mechanistically, FoxM1 positively regulated miR-335-3p by binding to its promoter region, while miR-335-3p targeted and negatively regulated Fmr1. Additionally, the promotive effect of miR-335-3p on NSC self-renewal occurred via p53 signaling pathway inactivation. Conclusion Taken together, miR-335-3p activated by FoxM1 could suppress NSC differentiation and promote NSC self-renewal by inactivating the p53 signaling pathway via Fmr1.