Global metabolomic profiling reveals hepatic biosignatures that reflect the unique metabolic needs of late-term mother and fetus

Alcohol Reprograms Placental Glucose and Lipid Metabolism, Which Correlate with Reduced Fetal Brain but not Body Weight in a Mouse Model of Prenatal Alcohol Exposure

BACKGROUND

Prenatal alcohol exposure (PAE) impairs fetal growth and brain development. Dysregulated placental function contributes to these deficits. Whether PAE also disrupts its metabolic functions to impede fetal development is unclear.

OBJECTIVES

We performed untargeted metabolomics to gain mechanistic insights on how PAE impacts placental metabolism and fetal nutrient availability.

METHODS

Pregnant C57BL/6J mice were gavaged with alcohol (ALC, 3 g/kg) or isocaloric maltodextrin (CON) daily on embryonic days (E) E8.5 through E17.5. We performed untargeted metabolomics on placentas harvested at E17.5.

RESULTS

Alcohol reduced placental glucose and glycolytic intermediates and increased tricarboxylic acid (TCA) cycle intermediates, suggesting a shift from glucose to lipids to meet its high energetic demands. This was complemented by elevations in intermediates of the pentose phosphate and glucosamine pathways, indicating a diversion of glucose into nonoxidative fates. Alcohol also decreased aspartate and asparagine, consistent with the limited glucose availability and increased fetal demand for nitrogen acceptors to support its increased gluconeogenesis and urea production. Alcohol also caused a selective increase in purine metabolites despite the limited availability of donor sources glucose, serine, glycine, glutamine, and asparagine. Uridine nucleotides were also elevated and may represent an adaptive change to meet the increased need for thiamin pyrophosphate in the oxidative decarboxylations of the TCA cycle and pentose phosphate pathways. Decreases in multiple oxylipins having antivasoconstriction actions could be a mechanism by which alcohol alters the placental vasculature and promotes vasoconstriction. Importantly, the selective and strong correlation of these dysregulated metabolites with reduced fetal brain weight, but not body weight, affirms the importance of the placenta-brain axis and placental metabolism on brain development.

CONCLUSIONS

Alcohol causes metabolic dysregulation and reprogramming of the late-term placenta. These changes limit fetal nutrient availability and contribute to the reduced brain development and cognitive impairments that partly typify PAE.

Impact of PFOS Exposure on Murine Fetal Hematopoietic Stem Cells, Associated with Intrauterine Metabolic Perturbation

This study hypothesized that perfluorooctanesulfonate (PFOS) exposure disrupts maternal-fetal metabolism, affecting fetal liver hematopoietic stem cell (FL-HSC) development. Pregnant mice received PFOS (0.3 and 3 μg/g bw) and were sacrificed on gestation day 14.5. Metabolomic analysis of maternal plasma revealed disruptions in steroid hormone, purine, carbohydrate, and amino acid metabolism, which aligned with the enriched pathways in amniotic fluid (AF). FL analysis indicated increased purine metabolism and disrupted glucose and amino acid metabolism. FL exhibited higher levels of polyunsaturated fatty acids, glycolytic and TCA metabolites, and pro-inflammatory cytokine IL-23, crucial for hematopoiesis regulation. Transcriptomic analysis of FL-HSCs revealed disturbances in the PPAR signaling pathway, pyruvate metabolism, oxidative phosphorylation, and amino acid metabolism, correlating with FL metabolic changes. Metabolomic analysis indicated significant rises in glycerophospholipid and vitamin B6 metabolism related to HSC expansion and differentiation. Flow cytometric analysis confirmed increased HSC populations and progenitor activation for megakaryocyte, erythrocyte, and lymphocyte lineages. The CFU assay showed a significant increase in BFU-E and CFU-G, but a decrease in CFU-GM in FL-HSCs from the H-PFOS group, indicating altered differentiation potential. These findings provide for the first time insights into the effects of PFOS on maternal-fetal metabolism and fetal hematopoiesis, highlighting implications for pollution-affected immune functions.

Maternal dietary intake among alcohol-exposed pregnancies is linked to early infant physical outcomes in South Africa

Maternal dietary intake is likely a contributing factor to fetal alcohol spectrum disorders (FASD). Two, 24-hour dietary recalls were completed by pregnant women (n = 196) in South African communities with high rates of FASD. More than 50% of all women in this study were below the Estimated Average Requirement (EAR) for pregnancy for vitamins A, C, D, E, riboflavin, vitamin B6, folate, calcium, magnesium, iron, and zinc. More than 90% of mothers were below the Recommended Dietary Allowance (RDA) or Adequate Intake (AI) for pregnancy on vitamin A, K, D, E, choline, calcium, magnesium, zinc, and potassium. More than 80% were below RDA/AI for pantothenic acid, vitamin B6, and folate. Women who consumed alcohol reported significantly lower intake of calcium and three saturated fatty acids and significantly higher intake of two monounsaturated fatty acids. On average, infants were < 40th centile on length, weight, and head circumference at 6 weeks old, regardless of alcohol exposure. Twenty nutrients correlated with at least one measure of 1st trimester drinking (drinks per drinking day, number of drinking days per week, and/or total drinks per week). Nutrients included four saturated fatty acids, eight amino acids, calcium, B-complex vitamins, choline, and betaine. Calcium correlated with all three drinking measures. Further analyses revealed seven nutrients were associated with infant length, weight, and/or head circumference among unexposed infants, and 12 nutrients were associated among infants with prenatal alcohol exposure. Inadequate maternal dietary intake, with alcohol exposure, may increase risk for poor infant growth and likelihood of FASD in this population.

Untargeted Metabolome Analysis of Alcohol-Exposed Pregnancies Reveals Metabolite Differences That Are Associated with Infant Birth Outcomes

Prenatal alcohol exposure can produce offspring growth deficits and is a leading cause of neurodevelopmental disability. We used untargeted metabolomics to generate mechanistic insight into how alcohol impairs fetal development. In the Western Cape Province of South Africa, 52 women between gestational weeks 5-36 (mean 18.5 ± 6.5) were recruited, and they provided a finger-prick fasting bloodspot that underwent mass spectrometry. Metabolomic data were analyzed using partial least squares-discriminant analyses (PLS-DA) to identify metabolites that correlated with alcohol exposure and infant birth outcomes. Women who consumed alcohol in the past seven days were distinguished by a metabolite profile that included reduced sphingomyelins, cholesterol, and pregnenolones, and elevated fatty acids, acyl and amino acyl carnitines, and androsterones. Using PLS-DA, 25 of the top 30 metabolites differentiating maternal groups were reduced by alcohol with medium-chain free fatty acids and oxidized sugar derivatives having the greatest influence. A separate ortho-PLS-DA analysis identified a common set of 13 metabolites that were associated with infant length, weight, and head circumference. These included monoacylglycerols, glycerol-3-phosphate, and unidentified metabolites, and most of their associations were negative, implying they represent processes having adverse consequences for fetal development.

A metabolomic study on the effect of prenatal exposure to Benzophenone-3 on spontaneous fetal loss in mice

Benzophenone-3 (BP-3) is widely used in a variety of cosmetics and is prevalent in drinking water or food, and women were under notable high exposure burden of BP-3. Reports show the associations between prenatal exposure to BP-3 and the risk of fetal loss, but its underlying mechanism remains largely unknown. Pregnant ICR mice were gavaged with BP-3 from gestational day (GD) 0 to GD 6 at doses of 0.1, 10 and 1000 mg/kg/day. The samples were collected on GD 12. Ultra-performance liquid chromatography coupled with mass spectrometry-based metabolomics was used to detect metabolome changes in fetal mice, the uterus and the placenta to identify the underlying mechanism. The results showed that the body weight and relative organ weights of the liver, brain and uterus of pregnant mice were not significantly changed between the control group and the treatment group. BP-3 increased fetal loss, and induced placental thrombosis and tissue necrosis with enhancement of platelet aggregation. Metabolomic analysis revealed that fructose and mannose metabolism, the TCA cycle, arginine and proline metabolism in the fetus, arginine and proline metabolism and biotin metabolism in the uterus, and arginine biosynthesis and pyrimidine metabolism in the placenta were the key changed pathways involved in the above changes. Our study indicates that exposure to BP-3 can induce placental thrombosis and fetal loss via the disruption of maternal and fetal metabolism in mice, providing novel insights into the influence of BP-3 toxicity on the female reproductive system.

Untargeted Metabolome Analysis Reveals Reductions in Maternal Hepatic Glucose and Amino Acid Content That Correlate with Fetal Organ Weights in a Mouse Model of Fetal Alcohol Spectrum Disorders

Prenatal alcohol exposure (PAE) causes fetal growth restrictions. A major driver of fetal growth deficits is maternal metabolic disruption; this is under-investigated following PAE. Untargeted metabolomics on the dam and fetus exposed to alcohol (ALC) revealed that the hepatic metabolome of ALC and control (CON) dams were distinct, whereas that of ALC and CON fetuses were similar. Alcohol reduced maternal hepatic glucose content and enriched essential amino acid (AA) catabolites, N-acetylated AA products, urea content, and free fatty acids. These alterations suggest an attempt to minimize the glucose gap by increasing gluconeogenesis using AA and glycerol. In contrast, ALC fetuses had unchanged glucose and AA levels, suggesting an adequate draw of maternal nutrients, despite intensified stress on ALC dams. Maternal metabolites including glycolytic intermediates, AA catabolites, urea, and one-carbon-related metabolites correlated with fetal liver and brain weights, whereas lipid metabolites correlated with fetal body weight, indicating they may be drivers of fetal weight outcomes. Together, these data suggest that ALC alters maternal hepatic metabolic activity to limit glucose availability, thereby switching to alternate energy sources to meet the high-energy demands of pregnancy. Their correlation with fetal phenotypic outcomes indicates the influence of maternal metabolism on fetal growth and development.