Immune network dysregulation associated with child neurodevelopmental delay: modulatory role of prenatal alcohol exposure

Moderate Prenatal Alcohol Exposure Increases Toll-like Receptor Activity in Umbilical Cord Blood at Birth: A Pilot Study

The prevalence of prenatal alcohol exposure (PAE) is increasing, with evidence suggesting that PAE is linked to an increased risk of infections. PAE is hypothesized to affect the innate immune system, which identifies pathogens through pattern recognition receptors, of which toll-like receptors (TLRs) are key components. We hypothesized that light-to-moderate PAE would impair immune responses, as measured by a heightened response in cytokine levels following TLR stimulation. Umbilical cord samples (10 controls and 8 PAE) from a subset of the Ethanol, Neurodevelopment, Infant and Child Health Study-2 cohort were included. Peripheral blood mononuclear cells (PMBCs) were stimulated with one agonist (TLR2, TLR3, TLR4, or TLR9). TLR2 agonist stimulation significantly increased pro-inflammatory interleukin-1-beta in the PAE group after 24 h. Pro- and anti-inflammatory cytokines were increased following stimulation with the TLR2 agonists. Stimulation with TLR3 or TLR9 agonists displayed minimal impact overall, but there were significant increases in the percent change of the control compared to PAE after 24 h. The results of this pilot investigation support further work into the impact on TLR2 and TLR4 response following PAE to delineate if alterations in levels of pro- and anti-inflammatory cytokines have clinical significance that could be used in patient management and/or attention to follow-up.

Prenatal environmental adversity and child neurodevelopmental delay: the role of maternal low-grade systemic inflammation and maternal anti-inflammatory diet

Maternal inflammation has been proposed as a possible pathway connecting prenatal environmental adversity (PEA), which includes maternal overweightness or obesity, diabetes, hypertensive disorders, and mood or anxiety disorders, to child neurodevelopmental delay. However, effective preventive measures have not yet been reported. Herein, we aimed to investigate whether a maternal anti-inflammatory diet reduced the risk of PEA-induced neurodevelopmental delay, by inhibiting inflammation. This prospective study included 7438 mother-child pairs. Maternal overweightness or obesity, diabetes, and hypertensive disorders were diagnosed before 28 week gestation. Maternal depression disorders were identified using the Edinburgh postnatal depression survey (EPDS) during mid-pregnancy. During mid- and late pregnancy, maternal high-sensitivity C-reactive protein (hs-CRP) levels were measured to evaluate systemic inflammation. The inflammatory potential of the diet was evaluated using the food-based empirical dietary inflammatory pattern (EDIP) score during mid-pregnancy. Pregnant women were classified into high- or low-score groups based on the median EDIP score. The outcomes of neurodevelopmental delay at 6-36 month postpartum were extracted from the Register of Child Healthcare. Among the 7438 mother-child pairs, 2937 (39.5%) were exposed to PEA, and neurodevelopmental delay occurred in 540 (7.3%). Children exposed to PEA had a higher risk of neurodevelopmental delay than those not exposed. PEA exposure was associated with increased hs-CRP during pregnancy in a PEA monotonic manner, an interquartile range increase in hs-CRP in mid- and late pregnancy was associated with an increased risk of child neurodevelopmental delay. Higher maternal persistent inflammation partially mediated the effect of PEA exposure on child neurodevelopmental delay by 17.19%. An increased risk of PEA-related neurodevelopmental delay was observed only in the children of mothers with high-EDIP rather than low-EDIP. These results suggest that increased systemic inflammation through mid- and late pregnancy mediates the association between PEA and child neurodevelopmental delay. A maternal anti-inflammatory diet may improve PEA-induced neurodevelopmental delay, by inhibiting inflammation.

Sex-specific alterations in cognitive control following moderate prenatal alcohol exposure and transient systemic hypoxia ischemia in the rat

BACKGROUND

Prenatal alcohol exposure (PAE) continues to be a worldwide problem. Affected offspring display impaired neurodevelopment, including difficulties with executive control. Although PAE has also been associated with decreased blood flow to fetuses, the relationship between PAE and altered blood flow is not well understood.

METHODS

We used preclinical models of PAE, transient systemic hypoxia ischemia (TSHI), and PAE + TSHI combined to assess the effects on neurodevelopmental outcomes using translationally relevant touchscreen operant platform testing. Twenty-eight Long-Evans (Blue Spruce, Strain HsdBlu:LE) dams were randomly assigned to one of four experimental groups: Saccharin Control (Sham), 5% Ethanol (PAE), TSHI, or 5% Ethanol and TSHI (PAE + TSHI). Dams consumed either saccharin or 5% ethanol during gestation. TSHI was induced on Embryonic Day 19 (E19) during an open laparotomy where the uterine arteries were transiently occluded for 1 h. Pups were born normally and, after weaning, were separated by sex. A total of 80 offspring, 40 males and 40 females, were tested on the 5-Choice Continuous Performance paradigm (5C-CPT).

RESULTS

Female offspring were significantly impacted by TSHI, but not PAE, with an increase in false alarms and a decrease in hit rates, omissions, accuracy, and correct choice latencies. In contrast, male offspring were mildly affected by PAE, but not TSHI, showing decreases in premature responses and increases in accuracy. No significant interactions between PAE and TSHI were detected on any measure.

CONCLUSION

Transient systemic hypoxia ischemia impaired performance on the 5C-CPT in females, leading to a bias toward stimulus responsivity regardless of stimulus type. In contrast, TSHI did not affect male offspring, and only slight effects of PAE were seen. Together, these data suggest that TSHI in females may cause alterations in cortical structures that override alterations caused by moderate PAE.

Developmental alcohol exposure is exhausting: Sleep and the enduring consequences of alcohol exposure during development

Prenatal alcohol exposure is the leading nongenetic cause of human intellectual impairment. The long-term impacts of prenatal alcohol exposure on health and well-being are diverse, including neuropathology leading to behavioral, cognitive, and emotional impairments. Additionally negative effects also occur on the physiological level, such as the endocrine, cardiovascular, and immune systems. Among these diverse impacts is sleep disruption. In this review, we describe how prenatal alcohol exposure affects sleep, and potential mechanisms of those effects. Furthermore, we outline the evidence that sleep disruption across the lifespan may be a mediator of some cognitive and behavioral impacts of developmental alcohol exposure, and thus may represent a promising target for treatment.

Impact of low-level prenatal alcohol exposure and maternal stress on autonomic regulation

BACKGROUND

Prenatal alcohol exposure (PAE) impacts the neurodevelopment of the fetus, including the infant's ability to self-regulate. Heart rate variability (HRV), that is, the beat-to-beat variability in heart rate, is a non-invasive measurement that can indicate autonomic nervous system (ANS) function/dysfunction.

METHODS

The study consisted of a subset of our ENRICH-2 cohort: 80 participants (32 PAE and 48 Controls) who had completed three visits during pregnancy. The participants completed a comprehensive assessment of PAE and other substances throughout pregnancy and assessments for stress, anxiety, and depression in the third trimester. At 24 h of age, infant HRV was assessed in the hospital during the clinically indicated heel lance; 3- to 5-min HRV epochs were obtained during baseline, heel lancing, and recovery episodes.

RESULTS

Parameters of HRV differed in infants with PAE compared to Controls during the recovery phase of the heel lance (respiratory sinus arrhythmia (RSA) and high-frequency (HF), p < 0.05). Increased maternal stress was also strongly associated with abnormalities in RSA, HF, and low-frequency / high-frequency (LF/HF, p's < 0.05).

CONCLUSIONS

Alterations in ANS regulation associated with PAE and maternal stress may reflect abnormal development of the hypothalamic-pituitary-adrenal axis and have long term implications for infant responsiveness and self-regulation.

IMPACT

Previous studies have focused on effects of moderate to heavy prenatal alcohol exposure (PAE) on autonomic dysregulation, but little is known about the effects of lower levels of PAE on infant self-regulation and heart rate variability (HRV). Prenatal stress is another risk factor for autonomic dysregulation. Mild PAE impacts infant self-regulation, which can be assessed using HRV. However, the effect of prenatal stress is stronger than that of mild PAE or other mental health variables on autonomic dysregulation.

Neuroinflammation in fetal alcohol spectrum disorders and related novel therapeutic approaches

Fetal alcohol spectrum disorders (FASD) is an umbrella term to describe the neurological effects of prenatal alcohol exposure (PAE). It has been extensively characterized that PAE causes cell proliferation disruption, heterotopias, and malformations in various brain regions and there is increasing evidence that neuroinflammation is responsible for some of these neurotoxic effects. Despite evidence of its importance, neuroinflammation is not usually considered at diagnosis or treatment for FASD. Here, we discuss the literature regarding anti- inflammatory drugs and nutraceuticals, which hold promise for future therapeutical interventions in these disorders.

Utility of the Zebrafish Model for Studying Neuronal and Behavioral Disturbances Induced by Embryonic Exposure to Alcohol, Nicotine, and Cannabis

It is estimated that 5% of pregnant women consume drugs of abuse during pregnancy. Clinical research suggests that intake of drugs during pregnancy, such as alcohol, nicotine and cannabis, disturbs the development of neuronal systems in the offspring, in association with behavioral disturbances early in life and an increased risk of developing drug use disorders. After briefly summarizing evidence in rodents, this review focuses on the zebrafish model and its inherent advantages for studying the effects of embryonic exposure to drugs of abuse on behavioral and neuronal development, with an emphasis on neuropeptides known to promote drug-related behaviors. In addition to stimulating the expression and density of peptide neurons, as in rodents, zebrafish studies demonstrate that embryonic drug exposure has marked effects on the migration, morphology, projections, anatomical location, and peptide co-expression of these neurons. We also describe studies using advanced methodologies that can be applied in vivo in zebrafish: first, to demonstrate a causal relationship between the drug-induced neuronal and behavioral disturbances and second, to discover underlying molecular mechanisms that mediate these effects. The zebrafish model has great potential for providing important information regarding the development of novel and efficacious therapies for ameliorating the effects of early drug exposure.

Alterations in Placental Inflammation-Related Gene Expression Partially Mediate the Effects of Prenatal Alcohol Consumption on Maternal Iron Homeostasis

Prenatal alcohol exposure (PAE) is associated with alterations in maternal and infant iron homeostasis that are consistent with changes seen in the setting of inflammation. We hypothesized that PAE leads to alterations in the placental expression of genes related to iron metabolism and inflammation that play functional roles in the teratogenic effects of alcohol on iron homeostasis. A total of 126 heavy-drinking women (≥1 oz (30 mL) absolute alcohol/day (~1.67 standard drinks/day) or women reporting binge drinking (≥2 drinks/occasion)) and 80 control women (<0.5 oz AA per day, no binging) in Cape Town, South Africa were interviewed prenatally regarding demographics, and alcohol, smoking, and drug use around conception and during pregnancy. Prenatal/maternal and infant hemoglobin and ferritin were measured. Whole-transcriptome RNA sequencing analysis was performed on flash-frozen transplacental tissue samples. Gene sets related to iron metabolism (n = 398) and inflammation (n = 467) were constructed by searching the Molecular Signatures Database for related ontology terms. Principal component analysis (PCA) yielded 59 factors for each theme. In multivariable regression models, PAE was related to 2 iron metabolism PCA factors (PCs) and 5 inflammation PCs, among which 2 iron metabolism and 4 inflammation factors were related to at least 1 key maternal or infant iron outcome. In causal inference analyses based on marginal structural models and the product method, the alterations in the expression profile of genes with functions in immune cell regulation, cytokine activity, angiogenesis, hematopoiesis, and ubiquitous cell processes appeared to partially mediate the relation of prenatal drinking frequency (days/week) around conception to a lower maternal hemoglobin-to-log(ferritin) ratio (proportion mediation = 51.35%). These findings suggest that placental inflammation may be partly responsible for the differences in alcohol-related iron homeostasis patterns between pregnant and non-pregnant adults.

Alcohol and Immunology: Mechanisms of multi-organ damage. Summary of the 2022 alcohol and Immunology research interest group (AIRIG) meeting

On October 26th, 2022 the annual Alcohol and Immunology Research Interest Group (AIRIG) meeting was held as a satellite symposium at the annual meeting of the Society for Leukocyte Biology in Hawaii. The 2022 meeting focused broadly on the immunological consequences of acute, chronic, and prenatal alcohol exposure and how these contribute to damage in multiple organs and tissues. These included alcohol-induced neuroinflammation, impaired lung immunity, intestinal dysfunction, and decreased anti-microbial and anti-viral responses. In addition, research presented covered multiple pathways behind alcohol-induced cellular dysfunction, including mitochondrial metabolism, cellular bioenergetics, gene regulation, and epigenetics. Finally, the work presented highlighted potential biomarkers and novel avenues of treatment for alcohol-induced organ damage.

Impact of the COVID-19 pandemic on adults with Fetal Alcohol Spectrum Disorder: linking immune function to mental health status

Prenatal alcohol exposure (PAE) is known to cause a variety of cognitive, behavioral, and neurological changes. Importantly, mental health problems are also overrepresented in individuals with Fetal Alcohol Spectrum Disorder (FASD), the group of neurodevelopmental conditions that can occur following PAE. Approximately 90% of individuals with FASD report experiencing mental health problems over their lifespan, compared to approximately 30% in the overall population. Individuals with FASD also display impairments in coping skills and increased vulnerability to stress. Here, we investigated whether the COVID-19 pandemic would have a differential impact on mental health and inflammation-to-mood associations in adults with FASD, compared to unexposed controls (no PAE). We capitalized on our pre-pandemic study examining health and immune function and invited past-participants to enroll in the current study. Participants completed mental health assessments and COVID-related questionnaires by phone. In addition, blood samples collected at baseline (pre-pandemic) were used to probe for inflammation-to-mood associations. Overall, our results indicate that lower SES was predictive of higher coronavirus anxiety scores, with no differences between adults with FASD and controls. In addition, while there were no differences in depression or anxiety measures at baseline (pre-pandemic) or during the pandemic, examination of inflammation-to-mood associations identified differential relationships in adults with FASD compared to unexposed controls. Specifically, there was a positive association between baseline neutrophil counts and both baseline and pandemic mental health scores in unexposed controls only. In addition, for unexposed controls there was also a negative association between baseline interferon-ɣ (IFN-ɣ) and pandemic mental health scores. By contrast, only adults with FASD showed positive associations between baseline interleukin-12p70 (IL-12p70), IL-8, soluble intercellular adhesion molecule-1 (sICAM-1), and soluble vascular cell adhesion molecule-1 (sVCAM-1) and pandemic mental health scores. Taken together, to our knowledge, this study is the first to examine the impact of the pandemic in adults with FASD. And while it may be too soon to predict the long-term effects of the pandemic on mental health, our data suggest that it will be important that future work also takes into account how immune function may be modulating mental health outcomes in this population.

Behavioral changes in FPR2/ALX and Chemr23 receptor knockout mice are exacerbated by prenatal alcohol exposure

Introduction

Prenatal alcohol exposure (PAE) causes neuroinflammation that may contribute to the pathophysiology underlying Fetal Alcohol Spectrum Disorder. Supplementation with omega-3 polyunsaturated fatty acids (PUFAs) has shown success in mitigating effects of PAE in animal models, however, the underlying mechanisms are unknown. Some PUFA metabolites, specialized pro-resolving mediators (SPMs), play a role in the resolution phase of inflammation, and receptors for these are in the brain.

Methods

To test the hypothesis that the SPM receptors FPR2 and ChemR23 play a role in PAE-induced behavioral deficits, we exposed pregnant wild-type (WT) and knockout (KO) mice to alcohol in late gestation and behaviorally tested male and female offspring as adolescents and young adults.

Results

Maternal and fetal outcomes were not different among genotypes, however, growth and behavioral phenotypes in the offspring did differ and the effects of PAE were unique to each line. In the absence of PAE, ChemR23 KO animals showed decreased anxiety-like behavior on the elevated plus maze and FPR2 KO had poor grip strength and low activity compared to age-matched WT mice. WT mice showed improved performance on fear conditioning between adolescence and young adulthood, this was not seen in either KO.

Discussion

This PAE model has subtle effects on WT behavior with lower activity levels in young adults, decreased grip strength in males between test ages, and decreased response to the fear cue indicating an effect of alcohol exposure on learning. The PAE-mediated decreased response to the fear cue was also seen in ChemR23 KO but not FPR2 KO mice, and PAE worsened performance of adolescent FPR2 KO mice on grip strength and activity. Collectively, these findings provide mechanistic insight into how PUFAs could act to attenuate cognitive impairments caused by PAE.

Prenatal alcohol exposure alters mRNA expression for stress peptides, glucocorticoid receptor function and immune factors in acutely stressed neonatal brain

Background

The amygdala, hippocampus and hypothalamus are critical stress regulatory areas that undergo functional maturation for stress responding initially established during gestational and early postnatal brain development. Fetal alcohol spectrum disorder (FASD), a consequence of prenatal alcohol exposure (PAE), results in cognitive, mood and behavioral disorders. Prenatal alcohol exposure negatively impacts components of the brain stress response system, including stress-associated brain neuropeptides and glucocorticoid receptors in the amygdala, hippocampus and hypothalamus. While PAE generates a unique brain cytokine expression pattern, little is known about the role of Toll-like receptor 4 (TLR4) and related proinflammatory signaling factors, as well as anti-inflammatory cytokines in PAE brain stress-responsive regions. We hypothesized that PAE sensitizes the early brain stress response system resulting in dysregulated neuroendocrine and neuroimmune activation.

Methods

A single, 4-h exposure of maternal separation stress in male and female postnatal day 10 (PND10) C57Bl/6 offspring was utilized. Offspring were from either prenatal control exposure (saccharin) or a limited access (4 h) drinking-in-the-dark model of PAE. Immediately after stress on PND10, the hippocampus, amygdala and hypothalamus were collected, and mRNA expression was analyzed for stress-associated factors (CRH and AVP), glucocorticoid receptor signaling regulators (GAS5, FKBP51 and FKBP52), astrocyte and microglial activation, and factors associated with TLR4 activation including proinflammatory interleukin-1β (IL-1β), along with additional pro- and anti-inflammatory cytokines. Select protein expression analysis of CRH, FKBP and factors associated with the TLR4 signaling cascade from male and female amygdala was conducted.

Results

The female amygdala revealed increased mRNA expression in stress-associated factors, glucocorticoid receptor signaling regulators and all of the factors critical in the TLR4 activation cascade, while the hypothalamus revealed blunted mRNA expression of all of these factors in PAE following stress. Conversely, far fewer mRNA changes were observed in males, notably in the hippocampus and hypothalamus, but not the amygdala. Statistically significant increases in CRH protein, and a strong trend in increased IL-1β were observed in male offspring with PAE independent of stressor exposure.

Conclusion

Prenatal alcohol exposure creates stress-related factors and TLR-4 neuroimmune pathway sensitization observed predominantly in females, that is unmasked in early postnatal life by a stress challenge.

Microbiota and nutrition as risk and resiliency factors following prenatal alcohol exposure

Alcohol exposure in adulthood can result in inflammation, malnutrition, and altered gastroenteric microbiota, which may disrupt efficient nutrient extraction. Clinical and preclinical studies have documented convincingly that prenatal alcohol exposure (PAE) also results in persistent inflammation and nutrition deficiencies, though research on the impact of PAE on the enteric microbiota is in its infancy. Importantly, other neurodevelopmental disorders, including autism spectrum and attention deficit/hyperactivity disorders, have been linked to gut microbiota dysbiosis. The combined evidence from alcohol exposure in adulthood and from other neurodevelopmental disorders supports the hypothesis that gut microbiota dysbiosis is likely an etiological feature that contributes to negative developmental, including neurodevelopmental, consequences of PAE and results in fetal alcohol spectrum disorders. Here, we highlight published data that support a role for gut microbiota in healthy development and explore the implication of these studies for the role of altered microbiota in the lifelong health consequences of PAE.

Prenatal alcohol exposure dysregulates spinal and circulating immune cell circular RNA expression in adult female rats with chronic sciatic neuropathy

Alcohol consumption during pregnancy is associated with Fetal Alcohol Spectrum Disorders (FASD) that results in a continuum of central nervous system (CNS) deficits. Emerging evidence from both preclinical and clinical studies indicate that the biological vulnerability to chronic CNS disease in FASD populations is driven by aberrant neuroimmune actions. Our prior studies suggest that, following minor nerve injury, prenatal alcohol exposure (PAE) is a risk factor for developing adult-onset chronic pathological touch sensitivity or allodynia. Allodynia in PAE rats occurs concurrently with heightened proinflammatory peripheral and spinal glial-immune activation. However, minor nerve-injured control rats remain non-allodynic, and corresponding proinflammatory factors are unaltered. A comprehensive molecular understanding of the mechanism(s) that underlie PAE-induced proinflammatory bias during adulthood remains elusive. Non-coding circular RNAs (circRNAs) are emerging as novel modulators of gene expression. Here, we hypothesized that PAE induces dysregulation of circRNAs that are linked to immune function under basal and nerve-injured conditions during adulthood. Utilizing a microarray platform, we carried out the first systematic profiling of circRNAs in adult PAE rats, prior to and after minor nerve injury. The results demonstrate a unique circRNA profile in adult PAE rats without injury; 18 circRNAs in blood and 32 spinal circRNAs were differentially regulated. Following minor nerve injury, more than 100 differentially regulated spinal circRNAs were observed in allodynic PAE rats. Bioinformatic analysis identified that the parental genes of these circRNAs are linked to the NF-κB complex, a central transcription factor for pain-relevant proinflammatory cytokines. Quantitative real-time PCR was employed to measure levels of selected circRNAs and linear mRNA isoforms. We have validated that circVopp1 was significantly downregulated in blood leukocytes in PAE rats, concurrent with downregulation of Vopp1 mRNA levels. Spinal circVopp1 levels were upregulated in PAE rats, regardless of nerve injury. Additionally, PAE downregulated levels of circItch and circRps6ka3, which are linked to immune regulation. These results demonstrate that PAE exerts long-lasting dysregulation of circRNA expression in blood leukocytes and the spinal cord. Moreover, the spinal circRNA expression profile following peripheral nerve injury is differentially modulated by PAE, potentially contributing to PAE-induced neuroimmune dysregulation.

Fetal alcohol spectrum disorders

Alcohol readily crosses the placenta and may disrupt fetal development. Harm from prenatal alcohol exposure (PAE) is determined by the dose, pattern, timing and duration of exposure, fetal and maternal genetics, maternal nutrition, concurrent substance use, and epigenetic responses. A safe dose of alcohol use during pregnancy has not been established. PAE can cause fetal alcohol spectrum disorders (FASD), which are characterized by neurodevelopmental impairment with or without facial dysmorphology, congenital anomalies and poor growth. FASD are a leading preventable cause of birth defects and developmental disability. The prevalence of FASD in 76 countries is >1% and is high in individuals living in out-of-home care or engaged in justice and mental health systems. The social and economic effects of FASD are profound, but the diagnosis is often missed or delayed and receives little public recognition. Future research should be informed by people living with FASD and be guided by cultural context, seek consensus on diagnostic criteria and evidence-based treatments, and describe the pathophysiology and lifelong effects of FASD. Imperatives include reducing stigma, equitable access to services, improved quality of life for people with FASD and FASD prevention in future generations.

Choline Supplementation Alters Hippocampal Cytokine Levels in Adolescence and Adulthood in an Animal Model of Fetal Alcohol Spectrum Disorders

Alcohol (ethanol) exposure during pregnancy can adversely affect development, with long-lasting consequences that include neuroimmune, cognitive, and behavioral dysfunction. Alcohol-induced alterations in cytokine levels in the hippocampus may contribute to abnormal cognitive and behavioral outcomes in individuals with fetal alcohol spectrum disorders (FASD). Nutritional intervention with the essential nutrient choline can improve hippocampal-dependent behavioral impairments and may also influence neuroimmune function. Thus, we examined the effects of choline supplementation on hippocampal cytokine levels in adolescent and adult rats exposed to alcohol early in development. From postnatal day (PD) 4-9 (third trimester-equivalent), Sprague-Dawley rat pups received ethanol (5.25 g/kg/day) or sham intubations and were treated with choline chloride (100 mg/kg/day) or saline from PD 10-30; hippocampi were collected at PD 35 or PD 60. Age-specific ethanol-induced increases in interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), and keratinocyte chemoattractant/human growth-regulated oncogene (KC/GRO) were identified in adulthood, but not adolescence, whereas persistent ethanol-induced increases of interleukin-6 (IL-6) levels were present at both ages. Interestingly, choline supplementation reduced age-related changes in interleukin-1 beta (IL-1β) and interleukin-5 (IL-5) as well as mitigating the long-lasting increase in IFN-γ in ethanol-exposed adults. Moreover, choline influenced inflammatory tone by modulating ratios of pro- to -anti-inflammatory cytokines. These results suggest that ethanol-induced changes in hippocampal cytokine levels are more evident during adulthood than adolescence, and that choline can mitigate some effects of ethanol exposure on long-lasting inflammatory tone.

Associations of circulation levels of cytokines with birthweight, preterm birth, spontaneous miscarriages, and stillbirth: A Mendelian randomization analysis

Background: The association between immune imbalances and adverse pregnancy outcomes has been extensive investigated by observational studies, but remain unclear. Thus, this study aimed to establish the causality of the circulation levels of cytokines on adverse pregnancy outcomes, such as offspring's birthweight (BW), preterm birth (PTB), spontaneous miscarriage (SM), and stillbirth (SB). Methods: Two-sample Mendelian randomization (MR) analysis was employed to investigate potential causal relations between 41 cytokines and pregnancy outcomes on the basis of previously published GWAS datasets. Multivariable MR (MVMR) analysis was implemented to investigate the effect of the composition of cytokine networks on the pregnancy outcomes. Potential risk factors were further estimated to explore the potential mediators. Results: Genetic correlation analysis based on large GWAS data sources revealed that genetically predicted MIP1b (β = -0.027, S.E. = 0.010, p = 0.009) and MCSF (β = -0.024, S.E. = 0.011, p = 0.029) were associated with reduced offspring's BW, MCP1 (OR: 0.90, 95% CI: 0.83-0.97, p = 0.007) was associated with reduced SM risk, SCF (β = -0.014, S.E. = 0.005, p = 0.012) associated with decreased number of SB in MVMR. The univariable MR showed that GROa (OR: 0.92, 95% CI: 0.87-0.97, p = 0.004) was associated with decreased PTB risk. Except for the MCSF-BW association, all above associations surpassed the Bonferroni corrected threshold. The MVMR results revealed that MIF, SDF1a, MIP1b, MCSF and IP10 composed cytokine networks, associated with offspring's BW. Risk factors analysis indicated that the above causal associations might be mediated by smoking behaviors. Conclusion: These findings suggest the causal associations of several cytokines with adverse pregnancy outcomes, which were potentially mediated by smoking and obesity. Some of the results did not been corrected through multiple tests and larger samples verification is required in further studies.

Epigenetic insight into effects of prenatal alcohol exposure on stress axis development: Systematic review with meta-analytic approaches

We conducted a systematic review with meta-analytic elements using publicly available Gene Expression Omnibus (GEO) datasets to determine the role of epigenetic mechanisms in prenatal alcohol exposure (PAE)-induced hypothalamic-pituitary-adrenal (HPA) axis dysfunctions in offspring. Several studies have demonstrated that PAE has long-term consequences on HPA axis functions in offspring. Some studies determined that alcohol-induced epigenetic alterations during fetal development persist in adulthood. However, additional research is needed to understand the major epigenetic events leading to alcohol-induced teratogenesis of the HPA axis. Our network analysis of GEO datasets identified key pathways relevant to alcohol-mediated histone modifications, DNA methylation, and miRNA involvement associated with PAE-induced alterations of the HPA axis. Our analysis indicated that PAE perturbated the epigenetic machinery to activate corticotrophin-releasing hormone, while it suppressed opioid, glucocorticoid receptor, and circadian clock genes. These results help to further our understanding of the epigenetic basis of alcohol's effects on HPA axis development.

Effects of Genetics and Sex on Acute Gene Expression Changes in the Hippocampus Following Neonatal Ethanol Exposure in BXD Recombinant Inbred Mouse Strains

Fetal alcohol spectrum disorders (FASD) are prevalent neurodevelopmental disorders. Genetics have been shown to have a role in the severity of alcohol's teratogenic effects on the developing brain. We previously identified recombinant inbred BXD mouse strains that show high (HCD) or low cell death (LCD) in the hippocampus following ethanol exposure. The present study aimed to identify gene networks that influence this susceptibility. On postnatal day 7 (3rd-trimester-equivalent), male and female neonates were treated with ethanol (5.0 g/kg) or saline, and hippocampi were collected 7hrs later. Using the Affymetrix microarray platform, ethanol-induced gene expression changes were identified in all strains with divergent expression sets found between sexes. Genes, such as Bcl2l11, Jun, and Tgfb3, showed significant strain-by-treatment interactions and were involved in many apoptosis pathways. Comparison of HCD versus LCD showed twice as many ethanol-induced genes changes in the HCD. Interestingly, these changes were regulated in the same direction suggesting (1) more perturbed effects in HCD compared to LCD and (2) limited gene expression changes that confer resistance to ethanol-induced cell death in LCD. These results demonstrate that genetic background and sex are important factors that affect differential cell death pathways after alcohol exposure during development that could have long-term consequences.

Altered bone and body composition in children and adolescents with confirmed prenatal alcohol exposure

Prenatal alcohol exposure can contribute to long term adverse health outcomes. Development of the skeletal system begins at the early embryonic stage and continues into early adulthood but the effect of prenatal alcohol exposure on skeletal growth is relatively unexplored in a clinical population. Here, we performed dual X-ray absorptiometry to examine bone, fat, and muscle accrual in children and adolescents diagnosed with, or at risk of, fetal alcohol spectrum disorders (FASDs). Children (aged 4-9 years) with FASD or at risk of FASD (n = 10) had similar growth to age matched controls (n = 27). By adolescence (aged ≥10 years), those with FASDs (n = 13) were shorter and had lower areal bone mineral density and lean tissue mass than typically developing peers (n = 29). Overall, adolescents diagnosed with FASDs had greater odds of impairments to bone and body composition. These findings highlight the importance of early FASD diagnosis and appropriate post-diagnostic medical follow-up to enable timely, effective interventions to optimize bone and body composition during paediatric growth.

Choline Supplementation Modifies the Effects of Developmental Alcohol Exposure on Immune Responses in Adult Rats

Prenatal alcohol exposure can disrupt the development of numerous systems, including the immune system. Indeed, alterations in cytokine levels may contribute to the neuropathological, behavioral, and cognitive problems, and other adverse outcomes observed in individuals with fetal alcohol spectrum disorders. Importantly, supplementation with the essential nutrient choline can improve performance in hippocampal-dependent behaviors; thus, the present study examined the effects of choline on plasma and hippocampal cytokines in adult rats exposed to ethanol in early development. From postnatal day (PD) 4–9 (third trimester equivalent), pups received ethanol (5.25 g/kg/day) or Sham intubations. Subjects were treated with choline chloride (100 mg/kg/day) or saline from PD10–30. On PD60, plasma and hippocampal tissue was collected before and after an immune challenge (lipopolysaccharide (LPS); 50 ug/kg). Prior to the immune challenge, ethanol-exposed subjects showed an overall increase in hippocampal pro-inflammatory cytokines, an effect mitigated by choline supplementation. In contrast, in the plasma, choline reduced LPS-related increases in pro-inflammatory markers, particularly in ethanol-exposed subjects. Thus, early choline supplementation may modify both brain and peripheral inflammation. These results suggest that early choline can mitigate some long-term effects of ethanol exposure on hippocampal inflammation, which may contribute to improved hippocampal function, and could also influence peripheral immune responses that may impact overall health.

Effects of prenatal opioid and alcohol exposures on immune and serotonin factors in human placenta

PURPOSE

Opioids and alcohol impact critical serotonin (5-HT) function in the developing placenta and fetus through the actions of immune proinflammatory factors. Yet, possible convergent effects of opioids and alcohol on human placental toll-like receptor 4 (TLR4) activation and subsequent 5-HT homeostasis remain entirely unknown. The purpose of this study was to examine the effect of prenatal exposure to opioids with or without prenatal alcohol exposure (PAE) on the expression of key placental immune and serotonin signaling factors in human placental tissue obtained from a well-characterized prospective cohort.

METHODS

Data were collected from a subset of participants enrolled in the prospective pre-birth Ethanol, Neurodevelopment, Infant, and Child Health (ENRICH-1) cohort. Women were recruited and classified into four study groups: 1) PAE (n = 20); 2) those taking medications for opioid use disorder (MOUD; n = 28), 3) concurrent PAE and MOUD (n = 20); and 4) controls (HC; n = 20) based on prospective, repeated self-report, and biomarker analysis. Placenta samples underwent tissue processing to identify mRNA for TLR4, nucleotide-binding oligomerization domain (NOD)-like receptor protein 3 (NLRP3), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), serotonin transporter (SERT), tryptophan hydroxylase (TPH1), indoleamine 2,3-Dioxygenase 1 (IDO) as well as protein concentrations of TLR4, IL-1β, TNF-α, SERT. To consider the association between study group and mRNA/protein expression of our targets, multivariable regression models were developed with inclusion of a priori selected covariates.

RESULTS

There was a significant negative association between PAE and SERT mRNA (β = -0.01; p < 0.01) and a positive association with TPH1 mRNA expression (β = 0.78; p < 0.05). In addition, there was a negative association between MOUD and TNF-α protein expression (β = -0.12; p < 0.05).

CONCLUSIONS

This study provides the first evidence that PAE may inhibit SERT expression while simultaneously promoting increased TPH1 protein expression in human placenta. This may result in increased 5-HT in fetal circulation known to affect neurodevelopment. Our data suggest that opioids and alcohol may disturb the bidirectional, dynamic interaction between the placental immune and serotonin system. Given the implication for brain development and health across the life-span further investigation of these critical mechanisms in well-defined cohorts is required.

Identifying Rare Genetic Variants of Immune Mediators as Risk Factors for Autism Spectrum Disorder

Autism spectrum disorder (ASD) affects more than 1% of children, and there is no viable pharmacotherapeutic agent to treat the core symptoms of ASD. Studies have shown that children with ASD show changes in their levels of immune response molecules. Our previous studies have shown that ASD is more common in children with folate receptor autoantibodies. We also found that children with ASD have abnormal gut immune function, which was characterized by a significant increase in the content of immunoglobulin A and an increase in gut-microbiota-associated epitope diversity. These studies suggest that the immune mechanism plays an important role in the occurrence of ASD. The present study aims to systematically assess gene mutations in immune mediators in patients with ASD. We collected genetic samples from 72 children with ASD (2−12 years old) and 107 healthy controls without ASD (20−78 years old). We used our previously-designed immune gene panel, which can capture cytokine and receptor genes, the coding regions of MHC genes, and genes of innate immunity. Target region sequencing (500×) and bioinformatics analytical methods were used to identify variants in immune response genes associated with patients with ASD. A total of 4 rare variants were found to be associated with ASD, including HLA-B: p.A93G, HLA-DQB1: p.S229N, LILRB2: p.R322H, and LILRB2: c.956-4C>T. These variants were present in 44.44% (32/72) of the ASD patients and were detected in 3.74% (4/107) of the healthy controls. We expect these genetic variants will serve as new targets for the clinical genetic assessment of ASD, and our findings suggest that immune abnormalities in children with ASD may have a genetic basis.

Fibroblast growth factor 2: Role in prenatal alcohol-induced stimulation of hypothalamic peptide neurons

Prenatal alcohol exposure (PAE) increases alcohol consumption and risk for alcohol use disorder. This phenomenon in rodents is suggested to involve a stimulatory effect of PAE, in female more than male offspring, on neurogenesis and density of neurons expressing neuropeptides in lateral hypothalamus (LH), including melanin-concentrating hormone (MCH), known to promote alcohol intake. With evidence suggesting a role for fibroblast growth factor 2 (FGF2) and its receptor FGFR1 in stimulating neurogenesis and alcohol drinking, we investigated here whether the FGF2-FGFR1 system is involved in the PAE-induced increase in MCH neurons, in postnatal offspring of pregnant rats given ethanol orally (embryonic day 10-15) at a low-moderate (2 g/kg/day) or high (5 g/kg/day) dose. Our results demonstrate that PAE at the low-moderate but not high dose stimulates FGF2 and FGFR1 gene expression and increases the density of MCH neurons co-expressing FGF2, only in females, but FGFR1 in both sexes. PAE induces this effect in the dorsal but not ventral area of the LH. Further analysis of FGF2 and FGFR1 transcripts within individual MCH neurons reveals an intracellular, sex-dependent effect, with PAE increasing FGF2 transcripts positively related to FGFR1 in the nucleus as well as cytoplasm of females but transcripts only in the cytoplasm of males. Peripheral injection of FGF2 itself (80 μg/kg, s.c.) in pregnant rats mimics these effects of PAE. Together, these results support the involvement of the FGF2-FGFR1 system in mediating the PAE-induced, sex dependent increase in density of MCH neurons, possibly contributing to increased alcohol consumption in the offspring.

Neurodevelopmental disorders, immunity, and cancer are connected

Immunity could be viewed as the common factor in neurodevelopmental disorders and cancer. The immune and nervous systems coevolve as the embryo develops. Immunity can release cytokines that activate MAPK signaling in neural cells. In specific embryonic brain cell types, dysregulated signaling that results from germline or embryonic mutations can promote changes in chromatin organization and gene accessibility, and thus expression levels of essential genes in neurodevelopment. In cancer, dysregulated signaling can emerge from sporadic somatic mutations during human life. Neurodevelopmental disorders and cancer share similarities. In neurodevelopmental disorders, immunity, and cancer, there appears an almost invariable involvement of small GTPases (e.g., Ras, RhoA, and Rac) and their pathways. TLRs, IL-1, GIT1, and FGFR signaling pathways, all can be dysregulated in neurodevelopmental disorders and cancer. Although there are signaling similarities, decisive differentiating factors are timing windows, and cell type specific perturbation levels, pointing to chromatin reorganization. Finally, we discuss drug discovery.

Markers of Neuroinflammation in the Serum of Prepubertal Children with Fetal Alcohol Spectrum Disorders

BACKGROUND

Fetal Alcohol Spectrum Disorders (FASD) are the manifestation of the damage caused by alcohol consumption during pregnancy. Children with Fetal Alcohol Syndrome (FAS), the extreme FASD manifestation, show both facial dysmorphology and mental retardation. Alcohol consumed during gestational age prejudices brain development by reducing, among others, the synthesis and release of neurotrophic factors and neuroinflammatory markers. Alcohol drinking also induces oxidative stress.

HYPOTHESIS/OBJECTIVE

The present study aimed to investigate the potential association between neurotrophins, neuroinflammation, and oxidative stress in 12 prepubertal male and female FASD children diagnosed as FAS or partial FAS (pFAS).

METHODS

Accordingly, we analyzed, in the serum, the level of BDNF and NGF and the oxidative stress, as Free Oxygen Radicals Test (FORT) and Free Oxygen Radicals Defense (FORD). Moreover, serum levels of inflammatory mediators (IL-1α, IL-2, IL-6, IL-10, IL-12, MCP-1, TGF-β, and TNF-α) involved in neuroinflammatory and oxidative processes have been investigated.

RESULTS

We demonstrated low serum levels of NGF and BDNF in pre-pubertal FASD children with respect to healthy controls. These changes were associated with higher serum presence of TNF- α and IL-1α. Quite interestingly, an elevation in the FORD was also found despite normal FORT levels. Moreover, we found a potentiation of IL-1α, IL-2, IL-10, and IL-1α1 in the analyzed female compared to male children.

CONCLUSION

The present investigation shows an imbalance in the peripheral neuroimmune pathways that could be used in children as early biomarkers of the deficits observed in FASD.

Intersection of Epigenetic and Immune Alterations: Implications for Fetal Alcohol Spectrum Disorder and Mental Health

Prenatal alcohol exposure can impact virtually all body systems, resulting in a host of structural, neurocognitive, and behavioral abnormalities. Among the adverse impacts associated with prenatal alcohol exposure are alterations in immune function, including an increased incidence of infections and alterations in immune/neuroimmune parameters that last throughout the life-course. Epigenetic patterns are also highly sensitive to prenatal alcohol exposure, with widespread alcohol-related alterations to epigenetic profiles, including changes in DNA methylation, histone modifications, and miRNA expression. Importantly, epigenetic programs are crucial for immune system development, impacting key processes such as immune cell fate, differentiation, and activation. In addition to their role in development, epigenetic mechanisms are emerging as attractive candidates for the biological embedding of environmental factors on immune function and as mediators between early-life exposures and long-term health. Here, following an overview of the impact of prenatal alcohol exposure on immune function and epigenetic patterns, we discuss the potential role for epigenetic mechanisms in reprogramming of immune function and the consequences for health and development. We highlight a range of both clinical and animal studies to provide insights into the array of immune genes impacted by alcohol-related epigenetic reprogramming. Finally, we discuss potential consequences of alcohol-related reprogramming of immune/neuroimmune functions and their effects on the increased susceptibility to mental health disorders. Overall, the collective findings from animal models and clinical studies highlight a compelling relationship between the immune system and epigenetic pathways. These findings have important implications for our understanding of the biological mechanisms underlying the long-term and multisystem effects of prenatal alcohol exposure, laying the groundwork for possible novel interventions and therapeutic strategies to treat individuals prenatally exposed to alcohol.

Adaptive Immune Deficiency Impairs Neural Activity After Training and Retrieval

Neuroimmune interactions have been studied for decades. Several neurodevelopmental disorders have been associated with immune dysfunction. However, the effects of immune system on neuronal function remain unknown. Herein, based on c-Fos protein expression, we characterized the brain areas that are activated after contextual fear conditioning (CFC) training or retrieval in severe combined immune deficiency (SCID) and wild-type mice. Further, we analyzed the interregional correlations of c-Fos activity that are affected by deficiency in adaptive immunity. Results showed significantly lower c-Fos density in learning and memory-associated brain regions of SCID mice after memory retrieval, but not during the CFC training. Moreover, SCID mice exhibited remarkably discordant interregional neuronal activities of learning neuron circuits after CFC training, which could be the cause of inefficient activation of the memory circuit after retrieval. These results provide a new perspective on how adaptive immunity affects neuronal function. Adaptive immune deficiency impairs the coordination of neural activity after training and retrieval, which might be a potential therapeutic target for neurodevelopmental disorders.

Prenatal alcohol-induced sex differences in immune, metabolic and neurobehavioral outcomes in adult rats

Prenatal alcohol exposure (PAE) can result in neurobehavioral anomalies, that may be exacerbated by co-occurring metabolic and immune system deficits. To test the hypothesis that the peripheral inflammation in adult PAE offspring is linked to poor glucose metabolism and neurocognitive deficits, pregnant Sprague-Dawley rats were exposed to ethanol vapor or ambient air during the latter half of gestation. We assessed, in adult offspring of both sexes, performance on a battery of neurocognitive behaviors, glucose tolerance, circulating and splenic immune cells by flow-cytometry, and circulating and tissue (liver, mesenteric adipose, and spleen) cytokines by multiplexed assays. PAE reduced both the ratio of spleen to body weight and splenic regulatory T-cell (Treg) numbers. PAE males, but not females exhibited an increase in circulating monocytes. Overall, PAE males exhibited a suppression of cytokine levels, while PAE females exhibited elevated cytokines in mesenteric adipose tissue (IL-6 and IL1α) and liver (IFN-γ, IL-1β, IL-13, IL-18, IL-12p70, and MCP-1), along with increased glucose intolerance. Behavioral analysis also showed sex-dependent PAE effects. PAE-males exhibited increased anxiety-like behavior while PAE-females showed decreased social interaction. PAE offspring of both sexes exhibited impaired recognition of novel objects. Multilinear regression modeling to predict the association between peripheral immune status, glucose intolerance and behavioral outcomes, showed that in PAE offspring, higher levels of adipose leptin and liver TNF- α predicted higher circulating glucose levels. Lower liver IL-1 α and higher plasma fractalkine predicted more time spent in the center of an open-field with sex being an additional predictor. Higher circulating and splenic Tregs predicted better social interaction in the PAE-offspring. Collectively, our data show that peripheral immune status is a persistent, sex-dependent predictor of glucose intolerance and neurobehavioral function in adult PAE offspring.

Association of Prenatal Alcohol Exposure and Prenatal Maternal Depression with Offspring Low-Grade Inflammation in Early Adolescence

(1) This longitudinal study aimed to investigate the link between prenatal alcohol exposure and prenatal maternal depression with the offspring’s low-grade inflammatory status. (2) Prenatal alcohol exposure was determined via maternal self-report during the 3rd trimester of pregnancy (self-report+: n = 29) and the meconium alcohol metabolite Ethyl Glucuronide (EtG), collected at birth (≥30 ng/g: n = 23). The Edinburgh Postnatal Depression Scale (EPDS) was used to screen for prenatal maternal depressive symptoms during the 3rd trimester (≥10: n = 35). Fifteen years later, 122 adolescents (M = 13.32 years; 48.4% female) provided blood samples for the analysis of high sensitivity C-reactive protein (hsCRP; M = 0.91; SD = 1.28). (3) Higher hsCRP levels were found in EtG positive adolescents (p = 0.036, ηp² = 0.04) and an inverse non-significant dose–response relation with hsCRP (r = −0.35, p = 0.113). For maternal self-reported prenatal alcohol consumption (p = 0.780, ηp² = 0.00) and prenatal depressive symptoms (p = 0.360, ηp² = 0.01) no differences for hsCRP levels between the affected and unaffected groups were found. (4) Adolescents with prenatal alcohol exposure are at risk for low-grade systemic inflammation. The EtG biomarker may be more accurate compared to self-reports. The findings suggest that prenatal maternal depression does not evoke low-grade systemic inflammation.

Oxidative stress marker aberrations in children with autism spectrum disorder: a systematic review and meta-analysis of 87 studies (N = 9109)

There is increasing awareness that oxidative stress may be implicated in the pathophysiology of autism spectrum disorder (ASD). Here we aimed to investigate blood oxidative stress marker profile in ASD children by a meta-analysis. Two independent investigators systematically searched Web of Science, PubMed, and Cochrane Library and extracted data from 87 studies with 4928 ASD children and 4181 healthy control (HC) children. The meta-analysis showed that blood concentrations of oxidative glutathione (GSSG), malondialdehyde, homocysteine, S-adenosylhomocysteine, nitric oxide, and copper were higher in children with ASD than that of HC children. In contrast, blood reduced glutathione (GSH), total glutathione (tGSH), GSH/GSSG, tGSH/GSSG, methionine, cysteine, vitamin B9, vitamin D, vitamin B12, vitamin E, S-adenosylmethionine/S-adenosylhomocysteine, and calcium concentrations were significantly reduced in children with ASD relative to HC children. However, there were no significance differences between ASD children and HC children for the other 17 potential markers. Heterogeneities among studies were found for most markers, and meta-regressions indicated that age and publication year may influence the meta-analysis results. These results therefore clarified blood oxidative stress profile in children with ASD, strengthening clinical evidence of increased oxidative stress implicating in pathogenesis of ASD. Additionally, given the consistent and large effective size, glutathione metabolism biomarkers have the potential to inform early diagnosis of ASD.

Altered Maternal Plasma Fatty Acid Composition by Alcohol Consumption and Smoking during Pregnancy and Associations with Fetal Alcohol Spectrum Disorders

Objective: Polyunsaturated fatty acids are vital for optimal fetal neuronal development. The relationship between maternal alcohol consumption and smoking with third trimester plasma fatty acids were examined and their association with Fetal Alcohol Spectrum Disorders (FASD).Methods: Moderate to heavy alcohol-using and low/unexposed comparison women were recruited during mid-pregnancy from two prenatal clinics in Ukraine. The participants' infants underwent physical and neurobehavioral exams prior to one-year of age and classified as having FASD by maternal alcohol consumption and neurobehavioral scores. A subset of mother-child pairs was selected representing three groups of cases and controls: Alcohol-Exposed with FASD (AE-FASD, n = 30), Alcohol-Exposed Normally Developing (AE-ND, n = 33), or Controls (n = 46). Third trimester maternal plasma samples were analyzed for fatty acids and levels were compared across groups.Results: The percent of C18:0 (p < 0.001), arachidonic acid (AA, C20:4n-6, p = 0.017) and C22:5n-6 (p = 0.001) were significantly higher in AE-FASD women than controls or AE-ND women. Alcohol-exposed women who smoked had lower C22:5n-3 (p = 0.029) and docosahexaenoic acid (DHA, C22:6n-3, p = 0.005) and higher C22:5n-6 (p = 0.013) than women consuming alcohol alone or abstainers.Conclusion: Alterations in fatty acid profiles were observed in moderate to heavy alcohol-consuming mothers with infants classified with FASD compared to alcohol-exposed normally developing infants or controls.