Dousing the flame: reviewing the mechanisms of inflammatory programming during stress-induced intrauterine growth restriction and the potential for ω-3 polyunsaturated fatty acid intervention

Depression in pregnant Hispanic women: Risk factors, pregnancy outcomes and plasma cytokines

Background

Maternal depression is considered a major contributor to morbidity and mortality in pregnancy. A population at risk are U.S. born or immigrant Hispanic women, and few prenatal depression or immune studies have focused on this population.

Objective

The research questions for the study were 1) What are the occurrences, risk factors and outcomes associated with depression in Hispanic pregnant women in the United States and 2) What are the associations of plasma immune cytokines and prenatal depression in this population.

Study design

Women of self-reported Hispanic ethnicity were born in the continental United States or foreign-born. Screening of potential participants (n = 690) at a first prenatal clinic visit consisted of antibody testing for Toxoplasma gondii antibodies in a larger grant, and only the women with antibody levels below the cutoff for T. gondii positivity (N = 536) were included in the present study. All participants completed a health and demographic questionnaire, the Edinburgh Postpartum Depression (EPDS) scale, the Perceived Stress Scale (PSS), and the Medical Outcomes Study Social Support (MOS) scale. We surveyed electronic health records (EHR) for risk factors and adverse pregnancy outcomes in the sample. We further measured physical and mental health and seven plasma immune cytokines at four study visits during pregnancy in a longitudinal subsample (N = 128).

Results

The frequency of EPDS scores of 10 (depression risk) or above was 18.6 % at the time of enrollment. Socioeconomic factors such as less education, greater unemployment, and U.S. born nativity were associated with greater depression risk, but these relationships became insignificant when we corrected for false discovery rate. Depression scores were not associated with adverse birth and pregnancy outcomes. The inflammatory cytokine TNF-α was significantly higher across pregnancy in women with depression risk (p < 0.03). Other inflammatory cytokines were higher in depressed women, but only at one time point in mid-pregnancy.

Conclusions

Prenatal depression occurs in early pregnancy and then declines in Hispanic women. The frequency of depression and stress were higher in U.S. born compared to immigrant Hispanic women. There was an elevation in plasma levels of TNF-α through the pregnancy in depressed women, and elevations in other cytokines, at midpregnancy. The adverse pregnancy outcomes, including preterm delivery, known to be associated with prenatal depression were not present in this cohort.

Maternal supplementation with n-3 fatty acids affects placental lipid metabolism, inflammation, oxidative stress, the endocannabinoid system, and the neonate cytokine concentrations in dairy cows

BACKGROUND

The placenta plays a crucial role in supporting and influencing fetal development. We compared the effects of prepartum supplementation with omega-3 (n-3) fatty acid (FA) sources, flaxseed oil (FLX) and fish oil (FO), on the expression of genes and proteins related to lipid metabolism, inflammation, oxidative stress, and the endocannabinoid system (ECS) in the expelled placenta, as well as on FA profile and inflammatory response of neonates. Late-pregnant Holstein dairy cows were supplemented with saturated fat (CTL), FLX, or FO. Placental cotyledons (n = 5) were collected immediately after expulsion, and extracted RNA and proteins were analyzed by RT-PCR and proteomic analysis. Neonatal blood was assessed for FA composition and concentrations of inflammatory markers.

RESULTS

FO increased the gene expression of fatty acid binding protein 4 (FABP4), interleukin 10 (IL-10), catalase (CAT), cannabinoid receptor 1 (CNR1), and cannabinoid receptor 2 (CNR2) compared with CTL placenta. Gene expression of ECS-enzyme FA-amide hydrolase (FAAH) was lower in FLX and FO than in CTL. Proteomic analysis identified 3,974 proteins; of these, 51-59 were differentially abundant between treatments (P ≤ 0.05, |fold change| ≥ 1.5). Top canonical pathways enriched in FLX vs. CTL and in FO vs. CTL were triglyceride metabolism and inflammatory processes. Both n-3 FA increased the placental abundance of FA binding proteins (FABPs) 3 and 7. The abundance of CNR1 cannabinoid-receptor-interacting-protein-1 (CNRIP1) was reduced in FO vs. FLX. In silico modeling affirmed that bovine FABPs bind to endocannabinoids. The FLX increased the abundance of inflammatory CD44-antigen and secreted-phosphoprotein-1, whereas prostaglandin-endoperoxide synthase 2 was decreased in FO vs. CTL placenta. Maternal FO enriched neonatal plasma with n-3 FAs, and both FLX and FO reduced interleukin-6 concentrations compared with CTL.

CONCLUSION

Maternal n-3 FA from FLX and FO differentially affected the bovine placenta; both enhanced lipid metabolism and modulated oxidative stress, however, FO increased some transcriptional ECS components, possibly related to the increased FABPs. Maternal FO induced a unique balance of pro- and anti-inflammatory components in the placenta. Taken together, different sources of n-3 FA during late pregnancy enhanced placental immune and metabolic processes, which may affect the neonatal immune system.

Interplay between maternal nutrition and epigenetic programming on offspring hypertension

Recent human and animal studies have delineated hypertension can develop in the earliest stage of life. A lack or excess of particular nutrients in the maternal diet may impact the expression of genes associated with BP, leading to an increased risk of hypertension in adulthood. Modulations in gene expression could be caused by epigenetic mechanisms through aberrant DNA methylation, histone modification, and microRNAs (miRNAs). Several molecular mechanisms for the developmental programming of hypertension, including oxidative stress, dysregulated nutrient-sensing signal, aberrant renin-angiotensin system, and dysbiotic gut microbiota have been associated with epigenetic programming. Conversely, maternal nutritional interventions such as amino acids, melatonin, polyphenols, resveratrol or short chain fatty acids may work as epigenetic modifiers to trigger protective epigenetic modifications and prevent offspring hypertension. We present a current perspective of maternal malnutrition that can cause fetal programming and the potential of epigenetic mechanisms lead to offspring hypertension. We also discuss the opportunities of dietary nutrients or nutraceuticals as epigenetic modifiers to counteract those adverse programming actions for hypertension prevention. The extent to which aberrant epigenetic changes can be reprogrammed or reversed by maternal dietary interventions in order to prevent human hypertension remains to be established. Continued research is necessary to evaluate the interaction between maternal malnutrition and epigenetic programming, as well as a greater focus on nutritional interventions for hypertension prevention towards their use in clinical translation.