Maternal Interleukin-6 concentration during pregnancy is associated with variation in frontolimbic white matter and cognitive development in early life

Labor epidural analgesia and autism spectrum disorder in 3-year-old offspring based on data from the Japan Environment and Children's Study: a prospective cohort study

OBJECTIVE

To evaluate the association between labor epidural analgesia (LEA) and autism spectrum disorder (ASD) in 3-year-old offspring in Japan.

METHODS

Prospective cohort study utilizing the Japan Environment and Children's Study, the largest nationwide birth cohort study. A total of 65,742 live singleton offspring were enrolled between January 2011 and March 2014. Offspring born via cesarean delivery or with confirmed chromosomal abnormalities were excluded. Multivariate logistic regression analyses were conducted to estimate adjusted odds ratios (aOR) and 95% confidence intervals (CI), accounting for maternal, paternal, and perinatal covariates. Subgroup analyses were performed based on the sex of the offspring. The primary outcome was the diagnosis of ASD at age 3.

RESULTS

Among the 65,742 offspring (33,684 boys [51.2%]; mean maternal age, 31.1 [4.9] years), 1,324 (2.0%) were exposed to LEA. ASD was diagnosed in 14 (1.1%) offspring exposed to LEA and 257 (0.4%) not exposed to LEA by age 3. After adjusting for potential confounders, multivariate logistic regression revealed that LEA was associated with an increased risk of ASD (aOR: 2.23; 95% CI: 1.28-3.87). Subgroup analysis indicated that the association was significant in male offspring (aOR: 2.55; 95% CI: 1.40-4.65), but not in female offspring (aOR: 1.41; 95% CI: 0.34-5.91).

CONCLUSION

This study suggests a mild association between LEA and ASD in 3-year-old male offspring. However, the findings should be cautiously interpreted given the limited number of ASD cases in this study. Causal relationships cannot be established since this was an observational study.

Interleukin-6 produces behavioral deficits in pre-pubescent mice independent of neuroinflammation

Maternal inflammation during pregnancy increases the offspring's risk of developing autism, ADHD, schizophrenia, and depression. Epidemiologic studies have demonstrated that maternal infections stimulate the production of interleukin-6 (IL-6), which can cross the placenta and fetal blood-brain barrier to alter brain development with functional and behavioral consequences. To model the effects of increased IL-6 between weeks 24-30 of human gestation, we injected male and female mice with 75 ng IL-6 twice daily, from P3 to P6. Our published studies have shown that this increases circulating IL-6 two-fold, alters post-pubescent ultrasonic vocalization patterns, reduces sociability, and increases self-grooming. However, most neurodevelopmental disorders in humans manifest in children as young as 2 years of age. Hence, a critical unexplored question is whether behavioral changes in immune activation models can be detected in pre-pubescent mice. Therefore, we evaluated early communication, sociability, and repetitive behaviors in pre-pubescent mice following the IL-6 treatment. A second open question is whether the cellular and behavioral changes are secondary to systemic or neuroinflammation. To address this question, we profiled 18 cytokines and chemokines in the circulation and CNS and evaluated eight immune cell types in P7 male and female brains following systemic IL-6 administration. We found an increase in ultrasonic vocalizations with simpler morphologies produced by the IL-6-injected male pups and a decrease in frequency in the female vocalizations upon removal from the nest at P7. The IL-6-treated male pups also socially interacted less when introduced to a novel mouse vs. controls as juveniles and spent almost twice as much time grooming themselves, a phenotype not present in the females. Tactile sensitivity was also increased, but only in the IL-6-treated female mice. The IL-6-treated mice had increased circulating IL-6 and IL-7 and reduced IL-13 at P7 that were no longer elevated at P14. There were no changes in brain levels of IL-6, IL-10, IL-13 or IL-17A mRNAs at P7. Altogether, these studies show that changes in the three core behavioral domains associated with several psychiatric disorders can be detected early in pre-pubescent mice following a transient developmental increase in IL-6. Yet, these behavioral alterations do not require neuroinflammation.

Maternal interleukin 6 in pregnancy is associated with everyday, but not test-based executive functioning in 10-year-old children

BACKGROUND

Elevated maternal interleukin 6 (IL-6) during pregnancy has been associated with adverse fetal brain development and neurodevelopmental disorders, which often involve executive functioning (EF) impairments. However, the association between maternal IL-6 levels during pregnancy and EF remains largely unexplored.

METHODS

The COPSYCH study is based on the prospective COPSAC2010 birth cohort of 700 mother-child pairs, recruited during pregnancy. The children's executive functioning was assessed at age 10 using: (i) the Behavior Rating Inventory of Executive Function, Second Edition (BRIEF-2) parental questionnaire, and (ii) a comprehensive neuropsychological test battery. Maternal blood levels of IL-6 and hs-CRP were measured at gestational week 24. Associations between IL-6 (main analysis) and hs-CRP (secondary analysis) and EF in children at age 10 were investigated with regression models with extensive confounder adjustment.

RESULTS

Six hundred and four children (86% of the cohort) completed the 10-year follow-up. Higher maternal IL-6 levels were significantly associated with less efficient parental-rated executive functioning in the children: BRIEF-2 Global Executive Composite score (p = 0.003), Behavior Regulation Index (p = 0.005), Emotion Regulation Index (p=0.04), and Cognitive Regulation Index (p=0.007). Interaction analysis with sex was significant (p-value=0.01) and exploratory analyses showed that IL-6 associations to BRIEF-2 were solely driven by boys. Associations between IL-6 and neuropsychological tests, as well as associations between hs-CRP and EF outcomes, were non-significant.

CONCLUSION

IL-6 during pregnancy was associated with less efficient everyday EF in children at age 10. If replicated, preventive strategies targeting inflammation in pregnancy may ameliorate adverse cognitive outcomes in offspring.

Season of conception and neurodevelopmental outcomes in singleton preterm infants less than 29 weeks gestation

Background

Environmental factors vary with the seasons and affect fetal development. Our objective was to assess the impact of the season of conception on neurodevelopmental outcomes at 18-21 months corrected age in singleton infants <29 weeks' gestation.

Methods

A retrospective cohort study of infants born between 2006 and 2015 at a tertiary-level neonatal intensive care unit was conducted. The conception date was calculated as the date of birth minus gestational age plus 14 days, and the conception dates were then divided into winter and non-winter months. The primary outcomes were a composite score of <85 in any of the cognitive, language, or motor components of the Bayley Scales of Infant and Toddler Development, 3rd edition (Bayley-III), at 18-21 months corrected gestational age, and scores of <85 in the individual components. Multivariate logistic regression was used to assess confounders.

Results

Of the 493 eligible infants, 162 (32.8%) were conceived in winter. There was no difference in the adjusted odds ratios (aORs) of any Bayley-III cognitive, language, or motor composite scores of <85 between the two groups. The aORs of cognitive and language scores <85 in the winter group were significantly higher [2.78, 95% confidence interval (CI) 1.37-5.65 and 1.97, 95% CI 1.07-3.62, respectively].

Conclusion

Singleton infants <29 weeks' gestation conceived in winter months have worse cognitive and language outcomes. Our results need validation in other and larger cohorts.

Granular cytoplasmic inclusions in astrocytes and microglial activation in the fetal brain of pigtail macaques in response to maternal viral infection

The fetal origins of neuropsychiatric disorders are poorly understood but have been linked to viral or inflammatory injury of the developing brain. The fetal white matter is particularly susceptible to injury as myelination, axonal growth, and deep white matter tracts become established. We have used the pigtail macaque (Macaca nemestrina) to study the maternal and fetal effects of influenza A virus (FLUAV) and Zika virus (ZIKV) infection during pregnancy, in cohorts with different time intervals between inoculation and delivery. We observed a striking histopathological alteration in a subset of astrocytes which contained granular cytoplasmic inclusions ("inclusion cells", ICs) within a specific region of the deep cerebral white matter in the fetal brains from specific FLUAV and ZIKV cohorts. Immunohistochemical and ultrastructural characteristics of ICs indicated that they are astrocytes (GFAP+) undergoing autophagocytosis (p62+) with activated lysosomes (LAMP1+, LAMP2+) and reactive changes in neighboring microglia. There was also a positive correlation between the number of ICs and LAMP1 or LAMP2 immunoreactivity in the fetal brain (LAMP1: rho 0.66; LAMP2: rho 0.54, p < 0.001 for both). Interestingly, ICs were significantly more prevalent in the 5-day FLUAV cohort and the 21-day intermediate ZIKV cohort than in controls (p < 0.005 and p = 0.04, respectively), but this relationship was not apparent in the ZIKV cohort with a shorter (2-3 days) or longer (months) time course. Virologic and immunologic assays indicated that the appearance of these cells was not linked with fetal brain infection. ICs were not observed in a macaque model of perinatal hypoxic ischemic encephalopathy. These alterations in fetal white matter are pathologically abnormal and may represent a transient neuropathologic finding that signifies a subtle brain injury in the fetus after maternal viral infection.

Understanding the potential impact of trimester-specific maternal immune activation due to SARS-CoV-2 on early human neurodevelopment and the role of cytokine balance

Purpose

The COVID-19 pandemic presents significant future health challenges. Its impact on pregnant women and their newborn is a particular area of concern. This study aims to examine the potential role of maternal immune activation (MIA), due to SARS-CoV-2 infection, on early neurodevelopment.

Methods

We analysed 107 mother-infant dyads from the COGESTCOV-19 study in Cantabria, Spain, which included 59 SARS-CoV-2 exposed (cases) and 48 unexposed (controls) mothers, recruited between December 2020 and February 2022. Cytokine levels (IL-6 and IL-10) were obtained from maternal blood and cord blood. Neurodevelopment was assessed using the Neonatal Behavioral Assessment Scale (NBAS) at six weeks of age. Trimester of infection was considered in the main analyses.

Results

Results showed no significant overall delays in early neurodevelopment due to maternal SARS-CoV-2 infection. Control infants performed better in some NBAS items. However, cases infants showed trimester-specific differences. First-trimester exposure was related to motor and reflex delays, second-trimester to poorer performances in motor tasks and autonomic stability, and third-trimester to weaker state organization, regulation, and reflexes. Some correlations between cytokine levels and NBAS performance showed moderate associations.

Conclusions

These findings highlight the need for ongoing neurodevelopmental monitoring of infants born during the COVID-19 pandemic. The study enhances our understanding of MIA's impact on early development, emphasizing the importance of addressing homeostatic mechanisms in mothers and newborns.

Maternal aging reduces female fecundity and alters offspring phenotype in a sex-specific manner

Context The age of childbearing in women has increased, with more babies born to women over 30years old than to those in their 20s. However, increasing maternal age is associated with a range of pregnancy and perinatal complications, such as reduced chance of conception, and higher risk of miscarriage or fetal death. Further, epidemiological studies indicate that advanced maternal age is also linked to a higher incidence of metabolic and neurodevelopmental disorders in offspring, such as Type 1 diabetes and autism spectrum disorder (ASD). Aims Mature female mice recapitulate many of the fertility characteristics seen in older women, such as reduced egg number and quality, providing a robust experimental model. This study examined fertility and offspring phenotypes in female mice at the onset of reproductive aging. Methods Firstly, fecundity in mice was measured from 3 to 18months of age. Secondly, reproductive outcomes in aged female mice (12months old) were compared to those of young females (3months of age). Growth of the offspring was assessed, as well as metabolism, behaviour, and immune function in adulthood. Key results Female aging reduced pregnancy rate, litter size and pup survival to weaning. Maternal age did not affect adult offspring immune function; however, female offspring had higher body weights, and male littermates presented dysregulated glucose tolerance and hyperactivity. Conclusions Maternal age affects offspring survival and health in a sex-specific manner. Implications These findings expand our understanding of maternal programming of offspring health, particularly the effects of increased age at pregnancy.

Prenatal Inflammation Reprograms Hypothalamic-Pituitary-Gonadal Axis Development in Female Rats

The hypothalamic-pituitary-gonadal (HPG) axis development during critical periods of ontogenesis can be disrupted by stress factors, including in particular maternal immune activation by infectious agents. Bacterial lipopolysaccharide (LPS, E.coli) exposure induces inflammation accompanied by proinflammatory cytokine release. The resulting elevated cytokine levels may lead to a disruption of epigenetic mechanisms regulating HPG axis development and to a reduced fertility in the offspring. This study focused on the long-term effects of prenatal LPS exposure on HPG axis development in female rats and the modulation of such effects by anti-inflammatory drugs: polyclonal IgG and monoclonal anti-IL6-receptor antibodies. LPS exposure on embryonic day 12 led to a decrease in the number of synaptic inputs on gonadotropin-releasing-hormone-producing neurons in the hypothalamus, high levels of follicular atresia, and suppressed steroidogenesis in the ovaries of adult female offspring. IgG treatment or IL6 receptor blockade by monoclonal antibodies 40 minutes after LPS exposure prevented these long-term negative effects of LPS. The data obtained suggest that IL6 is involved in the regulation of HPG axis development.

Exploring stress and depressive symptoms in pregnancy and the IL-1β, IL-6, and C-reactive protein pathway: Looking for possible biomarker targets

Background

Individuals undergo significant stress throughout pregnancy and are at high risk for depressive symptoms. Elevated stress and depressive symptoms are associated with inflammatory processes and adverse maternal-infant outcomes. However, the biological processes associated with psychosocial outcomes and the maternal immune system remain unclear. As such, we aimed to examine associations among perceived stress, depressive symptoms, salivary IL-1β, IL-6, and CRP levels, and hair and salivary cortisol levels during the second and third trimesters of pregnancy.

Methods

We conducted an ancillary study consisting of 37 pregnant individuals. Participants collected salivary samples and measures of perceived stress and depression at 17-19 weeks, 25-27 weeks, and 32-34 weeks gestation. We collected a one-time hair sample between 36 and 40 weeks. Provided salivary samples were used to detect changes in cortisol, IL-1β, IL-6, and CRP levels. Hair was used to detect changes in cortisol levels throughout pregnancy.

Results

Elevated levels of perceived stress and depressive symptoms are associated with increased salivary CRP levels, respectively (p = 0.0142, p = 0.0008). Salivary and hair cortisol increased significantly throughout the second and third trimesters of pregnancy (p = 0.0004 and p < 0.0001). We also observed variations in IL-6 during pregnancy (p = 0.029) and significant increases between 25 and 27 weeks (p = 0.016).

Conclusion

Salivary samples may provide a non-invasive measurement of alterations in cytokine and cortisol levels in pregnant individuals reporting elevated stress and depressive symptoms. These may be candidate biomarkers for mechanistic study possibly aiding providers in early detection of deleterious immunological processes which could result in adverse maternal-infant outcomes.

The association between maternal immune activation and brain structure and function in human offspring: a systematic review

Maternal immune activation (MIA) during pregnancy, as a result of infectious or inflammatory stimuli, has gained increasing attention for its potential role in adverse child neurodevelopment, with studies focusing on associations in children born preterm. This systematic review summarizes research on the link between several types of prenatal MIA and subsequent child structural and/or functional brain development outcomes. We identified 111 neuroimaging studies in five MIA areas: inflammatory biomarkers (n = 13), chorioamnionitis (n = 18), other types of infections (n = 18), human immunodeficiency virus (HIV) (n = 42), and Zika virus (n = 20). Overall, there was large heterogeneity in the type of MIA exposure examined and in study methodology. Most studies had a prospective single cohort design and mainly focused on potential effects on the brain up to one year after birth. The median sample size was 53 participants. Severe infections, i.e., HIV and Zika virus, were associated with various types of cerebral lesions (e.g., microcephaly, atrophy, or periventricular leukomalacia) that were consistently identified across studies. For less severe infections and chronic inflammation, findings were generally inconsistent and mostly included deviations in white matter structure/function. Current findings have been mainly observed in the infants' brain, presenting an opportunity for future studies to investigate whether these associations persist throughout development. Additionally, the inconsistent findings, encompassing both regions of interest and null results, call into question whether prenatal exposure to less severe infections and chronic inflammation exerts a small effect or no effect on child brain development.

Maternal Immune Activation and Child Brain Development: A Longitudinal Population-Based Multimodal Neuroimaging Study

BACKGROUND

Maternal immune activation (MIA) has been hypothesized to have an adverse effect on child neurodevelopment, but only a few neuroimaging studies have been performed to date, mostly in neonates. In this population-based cohort study, we investigated the association between MIA and multiple neuroimaging modalities depicting brain development from childhood to adolescence.

METHODS

We used data of mother-child pairs from the Generation R Study. To define our exposure, we measured interleukin (IL) 1β, IL-6, IL-17a, IL-23, interferon gamma, and C-reactive protein at 2 time points during pregnancy. Because levels of these 5 cytokines were highly correlated, we were able to compute a cytokine index. We used multiple brain imaging modalities as outcomes, including global and regional measures of brain morphology (structural magnetic resonance imaging, volume; n = 3295), white matter microstructure (diffusion magnetic resonance imaging, fractional anisotropy and mean diffusivity; n = 3267), and functional connectivity (functional magnetic resonance imaging, graph theory measures, and network-level connectivity; n = 2914) in the children at ages 10 and 14 years. We performed mixed effects models using child's age as a continuous time variable.

RESULTS

We found no significant effect of time on any neuroimaging outcomes in children over time, and there was no time × MIA interaction. These associations were similar for the cytokine index, C-reactive protein, and individual cytokines. We observed no evidence for differential effects of timing of prenatal MIA or child sex after multiple testing correction.

CONCLUSIONS

In this longitudinal population-based study, we found no evidence for an association between MIA and child brain development in the general population. Our findings differ from previous research in neonates that have shown structural and functional brain abnormalities after MIA.

From womb to world: The interplay between maternal immune activation, neuroglia, and neurodevelopment

This chapter introduces and discusses maternal immune activation (MIA) as a contributing factor in increasing the risk of neurodevelopmental disorders, particularly in relation to its interactions with neuroglia. Here we first provide an overview of the neuroglia-astroglia, oligodendroglia, microglia, and radial glial cells-and their important role during early brain development and in adulthood. We then present and discuss MIA, followed by a critical overview of inflammatory molecules and temporal stages associated to maternal inflammation during pregnancy. We provide an overview of animal and human models used to mimic and study MIA. Furthermore, we review the possible interaction between MIA and neuroglia, focusing on the current advances in both modeling and therapeutics. Additionally, we discuss and provide preliminary and interesting insights into the most recent pandemic, COVID-19, and how the infection may be associated to MIA and increased risk for neurodevelopmental disorders. Finally, we provide a critical overview of challenges and future opportunities to study how MIA may contribute to higher risk of developing neurodevelopmental disorders.

Sex-specific associations between maternal prenatal inflammation and offspring cortical morphology in youth: A harmonised study across four birth cohorts

Maternal immune activation (MIA) during pregnancy is implicated in offspring psychiatric disorders. However, it is unknown to what extent MIA affects neurodevelopment, particularly cerebrocortical anatomy, in the general population, and whether effects differ by sex. The current study used vertex-wise statistics to examine the association between maternal prenatal CRP, an archetypal systemic inflammatory marker, and offspring cortical thickness, surface area, and volume, in 2635 mother-child dyads (5.4-26.5 years) from three population-based cohorts, and one clinical cohort enriched for presence of inflammation markers. Maternal CRP within a normal physiological range (<10 mg/L) exhibited sex-specific quadratic associations with cortical morphological measures in 2 regions in males and 1 region in females at childhood. Elevated (>10 mg/L) CRP was associated with regional cortical morphology in females and in a pooled sample of sexes. Overall, MIA is associated with cortical development in a regional and sex-specific manner in studies spanning childhood to adulthood.

Cranial ultrasonographic findings in newborns exposed to SARS-CoV-2: a single-centre cross-sectional analysis

BACKGROUND

SARS-CoV-2's potential consequences on the developing brain are still unknown. The aim of this study was to describe cranial ultrasonographic (cUS) findings in a population of newborns exposed to SARS-CoV-2 born at San Marco Hospital in Catania.

METHODS

Two cohort of newborns, one exposed to SARS-CoV-2 both during gestation and at birth and one unexposed, were enrolled in this cross-sectional study conducted according to the STROBE guidelines (Strenghtening the Reporting of Observational Studies in Epidemiology) and underwent cUS. We performed a statistical analysis using the Fisher's exact test to assess whether significant differences among the two groups existed.

RESULTS

we enrolled 139 exposed newborns (62 females, 77 males with median gestational age 38.4 ± 1.9 W and median weight at birth 3142.8 ± 594.4 g) and 139 unexposed newborns (60 females, 79 males with median gestational age 38,9 ± 1.3 W and median weight at birth 3230 ± 336 g). cUS abnormalities were found in 32 exposed patients (23%) and in 23 (16.5%) unexposed patients. A statistically significant difference was found in the incidence of minor intracranial abnormalities (p 0.036) between exposed and unexposed patients and between newborns exposed during pregnancy and unexposed patients (p 0.016).

CONCLUSIONS

in our experience, the incidence of minor intracranial abnormalities was higher in SARS-COV-2-exposed newborns. Our results must be taken with caution and need further confirmation in larger studies but suggest to consider performing cUS at birth in newborns exposed to SARS-CoV-2 in research contexts.

Transcriptional and cellular response of hiPSC-derived microglia-neural progenitor co-cultures exposed to IL-6

Elevated interleukin (IL-)6 levels during prenatal development have been linked to increased risk for neurodevelopmental disorders (NDD) in the offspring, but the mechanism remains unclear. Human-induced pluripotent stem cell (hiPSC) models offer a valuable tool to study the effects of IL-6 on features relevant for human neurodevelopment in vitro. We previously reported that hiPSC-derived microglia-like cells (MGLs) respond to IL-6, but neural progenitor cells (NPCs) in monoculture do not. Therefore, we investigated whether co-culturing hiPSC-derived MGLs with NPCs would trigger a cellular response to IL-6 stimulation via secreted factors from the MGLs. Using N=4 donor lines without psychiatric diagnosis, we first confirmed that NPCs can respond to IL-6 through trans-signalling when recombinant IL-6Ra is present, and that this response is dose-dependent. MGLs secreted soluble IL-6R, but at lower levels than found in vivo and below that needed to activate trans-signalling in NPCs. Whilst transcriptomic and secretome analysis confirmed that MGLs undergo substantial transcriptomic changes after IL-6 exposure and subsequently secrete a cytokine milieu, NPCs in co-culture with MGLs exhibited a minimal transcriptional response. Furthermore, there were no significant cell fate-acquisition changes when differentiated into post-mitotic cultures, nor alterations in synaptic densities in mature neurons. These findings highlight the need to investigate if trans-IL-6 signalling to NPCs is a relevant disease mechanism linking prenatal IL-6 exposure to increased risk for psychiatric disorders. Moreover, our findings underscore the importance of establishing more complex in vitro human models with diverse cell types, which may show cell-specific responses to microglia-released cytokines to fully understand how IL-6 exposure may influence human neurodevelopment.

Maternal prenatal immune activation associated with brain tissue microstructure and metabolite concentrations in newborn infants

Few human studies have assessed the association of prenatal maternal immune activation (MIA) with measures of brain development and psychiatric risk in newborn offspring. Our goal was to identify the effects of MIA during the 2nd and 3rd trimesters of pregnancy on newborn measures of brain metabolite concentrations, tissue microstructure, and motor development. This was a prospective longitudinal cohort study conducted with nulliparous pregnant women who were aged 14 to 19 years and recruited in their 2nd trimester, as well as their children who were followed through 14 months of age. MIA was indexed by maternal interleukin-6 (IL-6) and C-reactive protein (CRP) in both trimesters of pregnancy. Primary outcomes included: (1) newborn brain metabolite concentrations as ratios to creatine (N-acetylaspartate (NAA)/creatine (Cr) and choline (Cho)/Cr) measured using Magnetic Resonance Spectroscopy; (2) newborn fractional anisotropy and mean diffusivity, measured using Diffusion Tensor Imaging; and (3) indices of motor development, assessed prenatally and postnatally at ages 4- and 14-months. Maternal IL-6 and CRP levels associated significantly with both metabolites in the putamen, thalamus, insula, and the internal capsule. Maternal IL-6 associated significantly with fractional anisotropy in the putamen, caudate, thalamus, insula, and precuneus, and with mean diffusivity in the inferior parietal and middle temporal gyrus. CRP associated significantly with fractional anisotropy in the thalamus, insula, and putamen. Significant associations were found in common regions across imaging modalities, though the direction of associations differed by immune marker. In addition, both maternal IL-6 and CRP (in both trimesters) prenatally associated significantly with offspring motor development at 4- and 14-months of age. The left thalamus mediated effects of IL-6 on postnatal motor development. These findings demonstrate that levels of MIA in mid- to late pregnancy in a generally healthy sample associate with tissue characteristics in newborn brain regions that primarily support motor integration and coordination, as well as behavioral regulation. Those brain effects may contribute to differences in motor development.

Advances in fetal and neonatal neuroimaging and everyday exposures

The complex, tightly regulated process of prenatal brain development may be adversely affected by "everyday exposures" such as stress and environmental pollutants. Researchers are only just beginning to understand the neural sequelae of such exposures, with advances in fetal and neonatal neuroimaging elucidating structural, microstructural, and functional correlates in the developing brain. This narrative review discusses the wide-ranging literature investigating the influence of parental stress on fetal and neonatal brain development as well as emerging literature assessing the impact of exposure to environmental toxicants such as lead and air pollution. These 'everyday exposures' can co-occur with other stressors such as social and financial deprivation, and therefore we include a brief discussion of neuroimaging studies assessing the effect of social disadvantage. Increased exposure to prenatal stressors is associated with alterations in the brain structure, microstructure and function, with some evidence these associations are moderated by factors such as infant sex. However, most studies examine only single exposures and the literature on the relationship between in utero exposure to pollutants and fetal or neonatal brain development is sparse. Large cohort studies are required that include evaluation of multiple co-occurring exposures in order to fully characterize their impact on early brain development. IMPACT: Increased prenatal exposure to parental stress and is associated with altered functional, macro and microstructural fetal and neonatal brain development. Exposure to air pollution and lead may also alter brain development in the fetal and neonatal period. Further research is needed to investigate the effect of multiple co-occurring exposures, including stress, environmental toxicants, and socioeconomic deprivation on early brain development.

Well controlled maternal inflammatory bowel disease does not increase the risk of abnormal neurocognitive outcome screening in offspring

Background

Exposure to maternal inflammation is associated with an increased risk of neurocognitive and developmental disorders in offspring. Early diagnosis and intervention improves childhood motor and cognitive functioning. Neonatal cerebral MRI and remote app-based generalised movement assessments (GMAs) are both predictive of adverse neurocognitive outcomes but have only been used in infants at significantly increased risk for these outcomes, rather than following in utero exposure to maternal inflammatory disorders.

Methods

Pregnant women with inflammatory bowel disease were assessed clinically and biochemically in each trimester of pregnancy in this single centre prospective study. Neonatal cerebral MRIs were performed at 6-12 weeks post-corrected term. Two GMA videos were filmed using the 'BabyMoves' app from 12 to 16 weeks of age. MRIs and GMAs were assessed by a blinded highly qualified practitioner using validated scoring systems.

Results

40/53 of invited maternal-infant dyads were recruited. C-reactive protein was elevated antenatally in less than 13%. 5/37 neonatal MRIs had incidental or obstetric trauma related gross anatomical abnormalities, with none abnormal on validated gross abnormality scoring. 3/35 GMAs were abnormal, with one GMA abnormality being clinically significant. Of those with abnormal GMAs, 2/3 were in exposed to severely active IBD in-utero.

Conclusion

Neonatal cerebral MRI and GMA for neurocognitive screening is feasible in the setting of maternal inflammatory bowel disease, where the risk of cerebral palsy is poorly defined and thus burdensome screening interventions are less appealing to parents. Larger studies are required to stratify adverse neurocognitive outcome risk in infants born to women with maternal inflammatory disorders, but these data are reassuring for women with IBD in remission antenatally.

Prenatal depression outcomes in the next generation: A critical review of recent DOHaD studies and recommendations for future research

Prenatal depression, a common pregnancy-related risk with a prevalence of 10-20 %, may affect in utero development and socioemotional and neurodevelopmental outcomes in the next generation. Although there is a growing body of work that suggests prenatal depression has an independent and long-lasting effect on offspring outcomes, important questions remain, and findings often do not converge. The present review examines work carried out in the last decade, with an emphasis on studies focusing on mechanisms and leveraging innovative technologies and study designs to fill in gaps in research. Overall, the past decade of research continues to suggest that prenatal depression increases risk for offspring socioemotional problems and may alter early brain development by affecting maternal-fetal physiology during pregnancy. However, important limitations remain; lack of diversity in study samples, inconsistent consideration of potential confounders (e.g., genetics, postnatal depression, parenting), and restriction of examination to narrow time windows and single exposures. On the other hand, exciting work has begun uncovering potential mechanisms underlying transmission, including alterations in mitochondria functioning, epigenetics, and the prenatal microbiome. We review the evidence to date, identify limitations, and suggest strategies for the next decade of research to detect mechanisms as well as sources of plasticity and resilience to ensure this work translates into meaningful, actionable science that improves the lives of families.

Inhibitory Systems in Brain Evolution: Pathways of Vulnerability in Neurodevelopmental Disorders

BACKGROUND

The evolution of the primate brain has been characterized by the reorganization of key structures and circuits underlying derived specializations in sensory systems, as well as social behavior and cognition. Among these, expansion and elaboration of the prefrontal cortex has been accompanied by alterations to the connectivity and organization of subcortical structures, including the striatum and amygdala, underlying advanced aspects of executive function, inhibitory behavioral control, and socioemotional cognition seen in our lineages. At the cellular level, the primate brain has further seen an increase in the diversity and number of inhibitory GABAergic interneurons. A prevailing hypothesis holds that disruptions in the balance of excitatory to inhibitory activity in the brain underlies the pathophysiology of many neurodevelopmental and psychiatric disorders.

SUMMARY

This review highlights the evolution of inhibitory brain systems and circuits and suggests that recent evolutionary modifications to GABAergic circuitry may provide the substrate for vulnerability to aberrant neurodevelopment. We further discuss how modifications to primate and human social organization and life history may shape brain development in ways that contribute to neurodivergence and the origins of neurodevelopmental disorders.

KEY MESSAGES

Many brain systems have seen functional reorganization in the mammalian, primate, and human brain. Alterations to inhibitory circuitry in frontostriatal and frontoamygdalar systems support changes in social behavior and cognition. Increased complexity of inhibitory systems may underlie vulnerabilities to neurodevelopmental and psychiatric disorders, including autism and schizophrenia. Changes observed in Williams syndrome may further elucidate the mechanisms by which alterations in inhibitory systems lead to changes in behavior and cognition. Developmental processes, including altered neuroimmune function and age-related vulnerability of inhibitory cells and synapses, may lead to worsening symptomatology in neurodevelopmental and psychiatric disorders.

BACKGROUND

The evolution of the primate brain has been characterized by the reorganization of key structures and circuits underlying derived specializations in sensory systems, as well as social behavior and cognition. Among these, expansion and elaboration of the prefrontal cortex has been accompanied by alterations to the connectivity and organization of subcortical structures, including the striatum and amygdala, underlying advanced aspects of executive function, inhibitory behavioral control, and socioemotional cognition seen in our lineages. At the cellular level, the primate brain has further seen an increase in the diversity and number of inhibitory GABAergic interneurons. A prevailing hypothesis holds that disruptions in the balance of excitatory to inhibitory activity in the brain underlies the pathophysiology of many neurodevelopmental and psychiatric disorders.

SUMMARY

This review highlights the evolution of inhibitory brain systems and circuits and suggests that recent evolutionary modifications to GABAergic circuitry may provide the substrate for vulnerability to aberrant neurodevelopment. We further discuss how modifications to primate and human social organization and life history may shape brain development in ways that contribute to neurodivergence and the origins of neurodevelopmental disorders.

KEY MESSAGES

Many brain systems have seen functional reorganization in the mammalian, primate, and human brain. Alterations to inhibitory circuitry in frontostriatal and frontoamygdalar systems support changes in social behavior and cognition. Increased complexity of inhibitory systems may underlie vulnerabilities to neurodevelopmental and psychiatric disorders, including autism and schizophrenia. Changes observed in Williams syndrome may further elucidate the mechanisms by which alterations in inhibitory systems lead to changes in behavior and cognition. Developmental processes, including altered neuroimmune function and age-related vulnerability of inhibitory cells and synapses, may lead to worsening symptomatology in neurodevelopmental and psychiatric disorders.

Prenatal Programming of Monocyte Chemotactic Protein-1 Signaling in Autism Susceptibility

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder that involves functional and structural defects in selective central nervous system (CNS) regions, harming the individual capability to process and respond to external stimuli, including impaired verbal and non-verbal communications. Etiological causes of ASD have not been fully clarified; however, prenatal activation of the innate immune system by external stimuli might infiltrate peripheral immune cells into the fetal CNS and activate cytokine secretion by microglia and astrocytes. For instance, genomic and postmortem histological analysis has identified proinflammatory gene signatures, microglia-related expressed genes, and neuroinflammatory markers in the brain during ASD diagnosis. Active neuroinflammation might also occur during the developmental stage, promoting the establishment of a defective brain connectome and increasing susceptibility to ASD after birth. While still under investigation, we tested the hypothesis whether the monocyte chemoattractant protein-1 (MCP-1) signaling is prenatally programmed to favor peripheral immune cell infiltration and activate microglia into the fetal CNS, setting susceptibility to autism-like behavior. In this review, we will comprehensively provide the current understanding of the prenatal activation of MCP-1 signaling by external stimuli during the developmental stage as a new selective node to promote neuroinflammation, brain structural alterations, and behavioral defects associated to ASD diagnosis.

Viral infections in pregnancy and impact on offspring neurodevelopment: mechanisms and lessons learned

Pregnant individuals with viral illness may experience significant morbidity and have higher rates of pregnancy and neonatal complications. With the growing number of viral infections and new viral pandemics, it is important to examine the effects of infection during pregnancy on both the gestational parent and the offspring. Febrile illness and inflammation during pregnancy are correlated with risk for autism, attention deficit/hyperactivity disorder, and developmental delay in the offspring in human and animal models. Historical viral epidemics had limited follow-up of the offspring of affected pregnancies. Infants exposed to seasonal influenza and the 2009 H1N1 influenza virus experienced increased risks of congenital malformations and neuropsychiatric conditions. Zika virus exposure in utero can lead to a spectrum of abnormalities, ranging from severe microcephaly to neurodevelopmental delays which may appear later in childhood and in the absence of Zika-related birth defects. Vertical infection with severe acute respiratory syndrome coronavirus-2 has occurred rarely, but there appears to be a risk for developmental delays in the infants with antenatal exposure. Determining how illness from infection during pregnancy and specific viral pathogens can affect pregnancy and neurodevelopmental outcomes of offspring can better prepare the community to care for these children as they grow. IMPACT: Viral infections have impacted pregnant people and their offspring throughout history. Antenatal exposure to maternal fever and inflammation may increase risk of developmental and neurobehavioral disorders in infants and children. The recent SARS-CoV-2 pandemic stresses the importance of longitudinal studies to follow pregnancies and offspring neurodevelopment.

Examining longitudinal associations between prenatal exposure to infections and child brain morphology

BACKGROUND

Maternal infection during pregnancy has been identified as a prenatal risk factor for the later development of psychopathology in exposed offspring. Neuroimaging data collected during childhood has suggested a link between prenatal exposure to maternal infection and child brain structure and function, potentially offering a neurobiological explanation for the emergence of psychopathology. Additionally, preclinical studies utilizing repeated measures of neuroimaging data suggest that effects of prenatal maternal infection on the offspring's brain may normalize over time (i.e., catch-up growth). However, it remains unclear whether exposure to prenatal maternal infection in humans is related to long-term differential neurodevelopmental trajectories. Hence, this study aimed to investigate the association between prenatal exposure to infections on child brain development over time using repeated measures MRI data.

METHODS

We leveraged data from a population-based cohort, Generation R, in which we examined prospectively assessed self-reported infections at each trimester of pregnancy (N = 2,155). We further used three neuroimaging assessments (at mean ages 8, 10 and 14) to obtain cortical and subcortical measures of the offspring's brain morphology with MRI. Hereafter, we applied linear mixed-effects models, adjusting for several confounding factors, to estimate the association of prenatal maternal infection with child brain development over time.

RESULTS

We found that prenatal exposure to infection in the third trimester was associated with a slower decrease in volumes of the pars orbitalis, rostral anterior cingulate and superior frontal gyrus, and a faster increase in the middle temporal gyrus. In the temporal pole we observed a divergent pattern, specifically showing an increase in volume in offspring exposed to more infections compared to a decrease in volume in offspring exposed to fewer infections. We further observed associations in other frontal and temporal lobe structures after exposure to infections in any trimester, though these did not survive multiple testing correction.

CONCLUSIONS

Our results suggest that prenatal exposure to infections in the third trimester may be associated with slower age-related growth in the regions: pars orbitalis, rostral anterior cingulate and superior frontal gyrus, and faster age-related growth in the middle temporal gyrus across childhood, suggesting a potential sensitive period. Our results might be interpreted as an extension of longitudinal findings from preclinical studies, indicating that children exposed to prenatal infections could exhibit catch-up growth. However, given the lack of differences in brain volume between various infection groups at baseline, there may instead be either a longitudinal deviation or a subtle temporal deviation. Subsequent well-powered studies that extend into the period of full brain development (∼25 years) are needed to confirm whether the observed phenomenon is indeed catch-up growth, a longitudinal deviation, or a subtle temporal deviation.

Prenatal maternal Inflammation, childhood cognition and adolescent depressive symptoms

BACKGROUND

Accumulating evidence indicates that higher prenatal maternal inflammation is associated with increased depression risk in adolescent and adult-aged offspring. Prenatal maternal inflammation (PNMI) may increase the likelihood for offspring to have lower cognitive performance, which, in turn, may heighten risk for depression onset. Therefore, this study explored the potential mediating role of childhood cognitive performance in the relationship between PNMI and adolescent depressive symptoms in offspring.

METHODS

Participants included 696 mother-offspring dyads from the Child Health and Development Studies (CHDS) cohort. Biomarkers of maternal inflammation [interleukin (IL)-6, IL-8, IL-1 receptor antagonist (IL-1RA) and soluble TNF receptor-II (sTNF-RII)] were assayed from first (T1) and second trimester (T2) sera. Childhood (ages 9-11) cognitive performance was assessed via standardized Peabody Picture Vocabulary Test (PPVT), a measure of receptive vocabulary correlated with general intelligence. Adolescent (ages 15-17) depressive symptoms were assessed via self-report.

RESULTS

There were no significant associations between T1 biomarkers and childhood PPVT or adolescent depressive symptoms. Higher T2 IL1-RA was directly associated with lower childhood PPVT (b = -0.21, SE = 0.08, t = -2.55, p = 0.01), but not with adolescent depressive symptoms. T2 IL-6 was not directly associated with childhood PPVT, but higher T2 IL-6 was directly associated at borderline significance with greater depressive symptoms in adolescence (b = 0.05, SE = 0.03, t = 1.96, p = 0.05). Lower childhood PPVT predicted significantly higher adolescent depressive symptoms (b = -0.07, SE = 0.02, t = -2.99, p < 0.01). There was a significant indirect effect of T2 IL-1RA on adolescent depressive symptoms via childhood PPVT (b = 0.03, 95 % CI = 0.002-0.03) indicating a partially mediated effect. No significant associations were found with T2 sTNF-RII nor IL-8.

CONCLUSIONS

Lower childhood cognitive performance, such as that indicated by a lower PPVT score, represents a potential mechanism through which prenatal maternal inflammation contributes to adolescent depression risk in offspring.

Aflatoxin B1 exposure deteriorates immune abnormalities in a BTBR T+ Itpr3tf/J mouse model of autism by increasing inflammatory mediators' production in CD19-expressing cells

Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by deficiencies in communication, repetitive and stereotyped behavioral patterns, and difficulties in reciprocal social engagement. The presence of immunological dysfunction in ASD has been well established. Aflatoxin B1 (AFB1) is a prevalent mycotoxin found in food and feed, causing immune toxicity and hepatotoxicity. AFB1 is significantly elevated in several regions around the globe. Existing research indicates that prolonged exposure to AFB1 results in neurological problems. The BTBR T+ Itpr3tf/J (BTBR) mice, which were used as an autism model, exhibit the primary behavioral traits that define ASD, such as repeated, stereotyped behaviors and impaired social interactions. The main objective of this work was to assess the toxic impact of AFB1 in BTBR mice. This work aimed to examine the effects of AFB1 on the expression of Notch-1, IL-6, MCP-1, iNOS, GM-CSF, and NF-κB p65 by CD19+ B cells in the spleen of the BTBR using flow cytometry. We also verified the impact of AFB1 exposure on the mRNA expression levels of Notch-1, IL-6, MCP-1, iNOS, GM-CSF, and NF-κB p65 in the brain of BTBR mice using real-time PCR. The findings of our study showed that the mice treated with AFB1 in the BTBR group exhibited a substantial increase in the presence of CD19+Notch-1+, CD19+IL-6+, CD19+MCP-1+, CD19+iNOS+, CD19+GM-CSF+, and CD19+NF-κB p65+ compared to the mice in the BTBR group that were treated with saline. Our findings also confirmed that administering AFB1 to BTBR mice leads to elevated mRNA expression levels of Notch-1, IL-6, MCP-1, iNOS, GM-CSF, and NF-κB p65 in the brain, in comparison to BTBR mice treated with saline. The data highlight that exposure to AFB1 worsens immunological abnormalities by increasing the expression of inflammatory mediators in BTBR mice.

Sex-Specific Pathways From Prenatal Maternal Inflammation to Adolescent Depressive Symptoms

Importance

Prenatal maternal inflammation has been associated with major depressive disorder in offspring in adulthood as well as with internalizing and externalizing symptoms in childhood; however, the association between prenatal inflammation and offspring depression in adolescence has yet to be examined.

Objective

To determine whether maternal levels of inflammatory biomarkers during pregnancy are associated with depressive symptomatology in adolescent-aged offspring and to examine how gestational timing, offspring sex, and childhood psychiatric symptoms impact these associations.

Design, Setting, and Participants

This was an observational study of a population-based birth cohort from the Child Health and Development Studies (CHDS), which recruited almost all mothers receiving obstetric care from the Kaiser Foundation Health Plan (KFHP) in Alameda County, California, between June 1959 and September 1966. Pregnancy data and blood sera were collected from mothers, and offspring psychiatric symptom data were collected in childhood (ages 9-11 years) and adolescence (ages 15-17 years). Mother-offspring dyads with available maternal prenatal inflammatory biomarkers during first and/or second trimesters and offspring depressive symptom data at adolescent follow-up were included. Data analyses took place between March 2020 and June 2023.

Exposures

Levels of inflammatory biomarkers (interleukin 6 [IL-6], IL-8, IL-1 receptor antagonist [IL-1RA], and soluble tumor necrosis factor receptor-II) assayed from maternal sera in the first and second trimesters of pregnancy.

Main Outcomes and Measures

Self-reported depressive symptoms at adolescent follow-up.

Results

A total of 674 mothers (mean [SD] age, 28.1 [5.9] years) and their offspring (350 male and 325 female) were included in this study. Higher second trimester IL-6 was significantly associated with greater depressive symptoms in offspring during adolescence (b, 0.57; SE, 0.26); P = .03). Moderated mediation analyses showed that childhood externalizing symptoms significantly mediated the association between first trimester IL-6 and adolescent depressive symptoms in male offspring (b, 0.18; 95% CI, 0.02-0.47), while childhood internalizing symptoms mediated the association between second trimester IL-1RA and adolescent depressive symptoms in female offspring (b, 0.80; 95% CI, 0.19-1.75).

Conclusions and Relevance

In this study, prenatal maternal inflammation was associated with depressive symptoms in adolescent-aged offspring. The findings of the study suggest that pathways to adolescent depressive symptomatology from prenatal risk factors may differ based on both the timing of exposure to prenatal inflammation and offspring sex.

Prenatal exposure to maternal disadvantage-related inflammatory biomarkers: associations with neonatal white matter microstructure

Prenatal exposure to heightened maternal inflammation has been associated with adverse neurodevelopmental outcomes, including atypical brain maturation and psychiatric illness. In mothers experiencing socioeconomic disadvantage, immune activation can be a product of the chronic stress inherent to such environmental hardship. While growing preclinical and clinical evidence has shown links between altered neonatal brain development and increased inflammatory states in utero, the potential mechanism by which socioeconomic disadvantage differentially impacts neural-immune crosstalk remains unclear. In the current study, we investigated associations between socioeconomic disadvantage, gestational inflammation, and neonatal white matter microstructure in 320 mother-infant dyads over-sampled for poverty. We analyzed maternal serum levels of four cytokines (IL-6, IL-8, IL-10, TNF-α) over the course of pregnancy in relation to offspring white matter microstructure and socioeconomic disadvantage. Higher average maternal IL-6 was associated with very low socioeconomic status (SES; INR < 200% poverty line) and lower neonatal corticospinal fractional anisotropy (FA) and lower uncinate axial diffusivity (AD). No other cytokine was associated with SES. Higher average maternal IL-10 was associated with lower FA and higher radial diffusivity (RD) in corpus callosum and corticospinal tracts, higher optic radiation RD, lower uncinate AD, and lower FA in inferior fronto-occipital fasciculus and anterior limb of internal capsule tracts. SES moderated the relationship between average maternal TNF-α levels during gestation and neonatal white matter diffusivity. When these interactions were decomposed, the patterns indicated that this association was significant and positive among very low SES neonates, whereby TNF-α was inversely and significantly associated with inferior cingulum AD. By contrast, among the more advantaged neonates (lower-to-higher SES [INR ≥ 200% poverty line]), TNF-α was positively and significantly associated with superior cingulum AD. Taken together, these findings suggest that the relationship between prenatal cytokine exposure and white matter microstructure differs as a function of SES. These patterns are consistent with a scenario where gestational inflammation's effects on white matter development diverge depending on the availability of foundational resources in utero.

Local glycolysis fuels actomyosin contraction during axonal retraction

In response to repulsive cues, axonal growth cones can quickly retract. This requires the prompt activity of contractile actomyosin, which is formed by the non-muscle myosin II (NMII) bound to actin filaments. NMII is a molecular motor that provides the necessary mechanical force at the expense of ATP. Here, we report that this process is energetically coupled to glycolysis and is independent of cellular ATP levels. Induction of axonal retraction requires simultaneous generation of ATP by glycolysis, as shown by chemical inhibition and genetic knock-down of GAPDH. Co-immunoprecipitation and proximal-ligation assay showed that actomyosin associates with ATP-generating glycolytic enzymes and that this association is strongly enhanced during retraction. Using microfluidics, we confirmed that the energetic coupling between glycolysis and actomyosin necessary for axonal retraction is localized to the growth cone and near axonal shaft. These results indicate a tight coupling between on-demand energy production by glycolysis and energy consumption by actomyosin contraction suggesting a function of glycolysis in axonal guidance.

Human brain organoid model of maternal immune activation identifies radial glia cells as selectively vulnerable

Maternal immune activation (MIA) during critical windows of gestation is correlated with long-term neurodevelopmental deficits in the offspring, including increased risk for autism spectrum disorder (ASD) in humans. Interleukin 6 (IL-6) derived from the gestational parent is one of the major molecular mediators by which MIA alters the developing brain. In this study, we establish a human three-dimensional (3D) in vitro model of MIA by treating induced pluripotent stem cell-derived dorsal forebrain organoids with a constitutively active form of IL-6, Hyper-IL-6. We validate our model by showing that dorsal forebrain organoids express the molecular machinery necessary for responding to Hyper-IL-6 and activate STAT signaling upon Hyper-IL-6 treatment. RNA sequencing analysis reveals the upregulation of major histocompatibility complex class I (MHCI) genes in response to Hyper-IL-6 exposure, which have been implicated with ASD. We find a small increase in the proportion of radial glia cells after Hyper-IL-6 treatment through immunohistochemistry and single-cell RNA-sequencing. We further show that radial glia cells are the cell type with the highest number of differentially expressed genes, and Hyper-IL-6 treatment leads to the downregulation of genes related to protein translation in line with a mouse model of MIA. Additionally, we identify differentially expressed genes not found in mouse models of MIA, which might drive species-specific responses to MIA. Finally, we show abnormal cortical layering as a long-term consequence of Hyper-IL-6 treatment. In summary, we establish a human 3D model of MIA, which can be used to study the cellular and molecular mechanisms underlying the increased risk for developing disorders such as ASD.

Placental inflammatory cytokines mRNA expression and preschool children's cognitive performance: a birth cohort study in China

BACKGROUND

The immunologic milieu at the maternal-fetal interface has profound effects on propelling the development of the fetal brain. However, accessible epidemiological studies concerning the association between placental inflammatory cytokines and the intellectual development of offspring in humans are limited. Therefore, we explored the possible link between mRNA expression of inflammatory cytokines in placenta and preschoolers' cognitive performance.

METHODS

Study subjects were obtained from the Ma'anshan birth cohort (MABC). Placental samples were collected after delivery, and real-time quantitative polymerase chain reaction (RT-qPCR) was utilized to measure the mRNA expression levels of IL-8, IL-1β, IL-6, TNF-α, CRP, IFN-γ, IL-10, and IL-4. Children's intellectual development was assessed at preschool age by using the Wechsler Preschool and Primary Scale of Intelligence, Fourth Edition (WPPSI-IV). Multiple linear regression and restricted cubic spline models were used for statistical analysis.

RESULTS

A total of 1665 pairs of mother and child were included in the analysis. After adjusting for confounders and after correction for multiple comparisons, we observed that mRNA expression of IL-8 (β =  - 0.53; 95% CI, - 0.92 to - 0.15), IL-6 (β =  - 0.58; 95% CI, - 0.97 to - 0.19), TNF-α (β =  - 0.37; 95% CI, - 0.71 to - 0.02), and IFN-γ (β =  - 0.31; 95% CI, - 0.61 to - 0.03) in the placenta was negatively associated with preschoolers' full scale intelligence quotient (FSIQ). Both higher IL-8 and IL-6 were associated with lower children's low fluid reasoning index (FRI), and higher IFN-γ was associated with lower children's working memory index (WMI). After further adjusting for confounders and children's age at cognitive testing, the integrated index of six pro-inflammatory cytokines (index 2) was found to be significantly and negatively correlated with both the FSIQ and each sub-dimension (verbal comprehension index (VCI), visual spatial index (VSI), FRI, WMI, processing speed index (PSI)). Sex-stratified analyses showed that the association of IL-8, IFN-γ, and index 2 with children's cognitive development was mainly concentrated in boys.

CONCLUSIONS

Evidence of an association between low cognitive performance and high expression of placental inflammatory cytokines (IL-8, IL-6, TNF-α, and IFN-γ) was found, highlighting the potential importance of intrauterine placental immune status in dissecting offspring cognitive development.

Disruption of Intranasal GnRH Neuronal Migration Route into the Brain Induced by Proinflammatory Cytokine IL-6: Ex Vivo and In Vivo Rodent Models

Maternal immune activation results in altered levels of cytokines in the maternal-fetal system, which has a negative impact on fetal development, including the gonadotropin-releasing hormone (GnRH) system, which is crucial for the reproduction. Suppression of GnRH-neuron migration may be associated with cytokine imbalances, and primarily with proinflammatory cytokine interleukin (IL)-6. This study aimed to determine the effects of IL-6 and monoclonal antibody to IL-6 or IL-6R or polyclonal IgG on the formation of migration route of GnRH-neurons in ex vivo and in vivo rodent models on day 11.5 of embryonic development. The increased level of IL-6 in mouse nasal explants suppressed peripherin-positive fiber outgrowth, while this led to an increase in the number of GnRH-neurons in the nose and olfactory bulbs and a decrease in their number in the fetal brain. This effect is likely to be realized via IL-6 receptors along the olfactory nerves. The suppressive effect of IL-6 was diminished by monoclonal antibodies to IL-6 or its receptors and by IgG.

Long-term effects of prenatal infection on the human brain: a prospective multimodal neuroimaging study

There is convincing evidence from rodent studies suggesting that prenatal infections affect the offspring's brain, but evidence in humans is limited. Here, we assessed the occurrence of common infections during each trimester of pregnancy and examined associations with brain outcomes in adolescent offspring. Our study was embedded in the Generation R Study, a large-scale sociodemographically diverse prospective birth cohort. We included 1094 mother-child dyads and investigated brain morphology (structural MRI), white matter microstructure (DTI), and functional connectivity (functional MRI), as outcomes at the age of 14. We focused on both global and focal regions. To define prenatal infections, we composed a score based on the number and type of infections during each trimester of pregnancy. Models were adjusted for several confounders. We found that prenatal infection was negatively associated with cerebral white matter volume (B = -0.069, 95% CI -0.123 to -0.015, p = 0.011), and we found an association between higher prenatal infection scores and smaller volumes of several frontotemporal regions of the brain. After multiple testing correction, we only observed an association between prenatal infections and the caudal anterior cingulate volume (B = -0.104, 95% CI -0.164 to -0.045, p < 0.001). We did not observe effects of prenatal infection on other measures of adolescent brain morphology, white matter microstructure, or functional connectivity, which is reassuring. Our results show potential regions of interest in the brain for future studies; data on the effect of severe prenatal infections on the offspring's brain in humans are needed.

Beyond TORCH: A narrative review of the impact of antenatal and perinatal infections on the risk of disability

Infections and inflammation during pregnancy or early life can alter child neurodevelopment and increase the risk for structural brain abnormalities and mental health disorders. There is strong evidence that TORCH infections (i.e., Treponema pallidum, Toxoplasma gondii, rubella virus, cytomegalovirus, herpes virus) alter fetal neurodevelopment across multiple developmental domains and contribute to motor and cognitive disabilities. However, the impact of a broader range of viral and bacterial infections on fetal development and disability is less well understood. We performed a literature review of human studies to identify gaps in the link between maternal infections, inflammation, and several neurodevelopmental domains. We found strong and moderate evidence respectively for a higher risk of motor and cognitive delays and disabilities in offspring exposed to a range of non-TORCH pathogens during fetal life. In contrast, there is little evidence for an increased risk of language and sensory disabilities. While guidelines for TORCH infection prevention during pregnancy are common, further consideration for prevention of non-TORCH infections during pregnancy for fetal neuroprotection may be warranted.

Extracellular free water elevations are associated with brain volume and maternal cytokine response in a longitudinal nonhuman primate maternal immune activation model

Maternal infection has emerged as an important environmental risk factor for neurodevelopmental disorders, including schizophrenia and autism spectrum disorders. Animal model systems of maternal immune activation (MIA) suggest that the maternal immune response plays a significant role in the offspring's neurodevelopment and behavioral outcomes. Extracellular free water is a measure of freely diffusing water in the brain that may be associated with neuroinflammation and impacted by MIA. The present study evaluates the brain diffusion characteristics of male rhesus monkeys (Macaca mulatta) born to MIA-exposed dams (n = 14) treated with a modified form of the viral mimic polyinosinic:polycytidylic acid at the end of the first trimester. Control dams received saline injections at the end of the first trimester (n = 10) or were untreated (n = 4). Offspring underwent diffusion MRI scans at 6, 12, 24, 36, and 45 months. Offspring born to MIA-exposed dams showed significantly increased extracellular free water in cingulate cortex gray matter starting as early as 6 months of age and persisting through 45 months. In addition, offspring gray matter free water in this region was significantly correlated with the magnitude of the maternal IL-6 response in the MIA-exposed dams. Significant correlations between brain volume and extracellular free water in the MIA-exposed offspring also indicate converging, multimodal evidence of the impact of MIA on brain development. These findings provide strong evidence for the construct validity of the nonhuman primate MIA model as a system of relevance for investigating the pathophysiology of human neurodevelopmental psychiatric disorders. Elevated free water in individuals exposed to immune activation in utero could represent an early marker of a perturbed or vulnerable neurodevelopmental trajectory.

Gestational and postnatal age associations for striatal tissue iron deposition in early infancy

Striatal development is crucial for later motor, cognitive, and reward behavior, but age-related change in striatal physiology during the neonatal period remains understudied. An MRI-based measure of tissue iron deposition, T2*, is a non-invasive way to probe striatal physiology neonatally, linked to dopaminergic processing and cognition in children and adults. Striatal subregions have distinct functions that may come online at different time periods in early life. To identify if there are critical periods before or after birth, we measured if striatal iron accrued with gestational age at birth [range= 34.57-41.85 weeks] or postnatal age at scan [range= 5-64 days], using MRI to probe the T2* signal in N = 83 neonates in three striatal subregions. We found iron increased with postnatal age in the pallidum and putamen but not the caudate. No significant relationship between iron and gestational age was observed. Using a subset of infants scanned at preschool age (N = 26), we show distributions of iron shift between time points. In infants, the pallidum had the least iron of the three regions but had the most by preschool age. Together, this provides evidence of distinct change for striatal subregions, a possible differentiation between motor and cognitive systems, identifying a mechanism that may impact future trajectories.

Fetal Frontolimbic Connectivity Prospectively Associates With Aggression in Toddlers

Background

Aggression is a major public health concern that emerges early in development and lacks optimized treatment, highlighting need for improved mechanistic understanding regarding the etiology of aggression. The present study leveraged fetal resting-state functional magnetic resonance imaging to identify candidate neurocircuitry for the onset of aggressive behaviors before symptom emergence.

Methods

Pregnant mothers were recruited during the third trimester of pregnancy to complete a fetal resting-state functional magnetic resonance imaging scan. Mothers subsequently completed the Child Behavior Checklist to assess child aggression at 3 years postpartum (n = 79). Independent component analysis was used to define frontal and limbic regions of interest.

Results

Child aggression was not related to within-network connectivity of subcortical limbic regions or within-medial prefrontal network connectivity in fetuses. However, weaker functional coupling between the subcortical limbic network and medial prefrontal network in fetuses was prospectively associated with greater maternal-rated child aggression at 3 years of age even after controlling for maternal emotion dysregulation and toddler language ability. We observed similar, but weaker, associations between fetal frontolimbic functional connectivity and toddler internalizing symptoms.

Conclusions

Neural correlates of aggressive behavior may be detectable in utero, well before the onset of aggression symptoms. These preliminary results highlight frontolimbic connections as potential candidate neurocircuitry that should be further investigated in relation to the unfolding of child behavior and psychiatric risk.

Effects of physical activity in child and adolescent depression and anxiety: role of inflammatory cytokines and stress-related peptide hormones

Depression and anxiety are the most common mental illnesses affecting children and adolescents, significantly harming their well-being. Research has shown that regular physical activity can promote cognitive, emotional, fundamental movement skills, and motor coordination, as a preventative measure for depression while reducing the suicide rate. However, little is known about the potential role of physical activity in adolescent depression and anxiety. The studies reviewed in this paper suggest that exercise can be an effective adjunctive treatment to improve depressive and anxiety symptoms in adolescents, although research on its neurobiological effects remains limited.

Maternal prenatal immune activation associated with brain tissue microstructure and metabolite concentrations in newborn infants

Importance

Few translational human studies have assessed the association of prenatal maternal immune activation with altered brain development and psychiatric risk in newborn offspring.

Objective

To identify the effects of maternal immune activation during the 2nd and 3rd trimesters of pregnancy on newborn brain metabolite concentrations, tissue microstructure, and longitudinal motor development.

Design

Prospective longitudinal cohort study conducted from 2012 - 2017.

Setting

Columbia University Irving Medical Center and Weill Cornell Medical College.

Participants

76 nulliparous pregnant women, aged 14 to 19 years, were recruited in their 2nd trimester, and their children were followed through 14 months of age.

Exposure

Maternal immune activation indexed by maternal interleukin-6 and C-reactive protein in the 2nd and 3rd trimesters of pregnancy.

Main Outcomes and Measures

The main outcomes included (1) newborn metabolite concentrations, measured as N-acetylaspartate, creatine, and choline using Magnetic Resonance Spectroscopy; (2) newborn fractional anisotropy and mean diffusivity measured using Diffusion Tensor Imaging; and (3) indices of motor development assessed prenatally and postnatally at ages 4- and 14-months.

Results

Maternal interleukin-6 and C-reactive protein levels in the 2nd or 3rd trimester were significantly positively associated with the N-acetylaspartate, creatine, and choline concentrations in the putamen, thalamus, insula, and anterior limb of the internal capsule. Maternal interleukin-6 was associated with fractional anisotropy in the putamen, insula, thalamus, precuneus, and caudate, and with mean diffusivity in the inferior parietal and middle temporal gyrus. C-reactive protein was associated with fractional anisotropy in the thalamus, insula, and putamen. Regional commonalities were found across imaging modalities, though the direction of the associations differed by immune marker. In addition, a significant positive association was observed between offspring motor development and both maternal interleukin-6 and C-reactive protein (in both trimesters) prenatally and 4- and 14-months of age.

Conclusions and Relevance

Using a healthy sample, these findings demonstrate that levels of maternal immune activation in mid- to late pregnancy associate with tissue characteristics in newborn brain regions primarily supporting motor integration/coordination and behavioral regulation and may lead to alterations in motor development.

Gestational and postnatal age associations for striatal tissue iron deposition in early infancy

Striatal development is crucial for later motor, cognitive, and reward behavior, but age-related change in striatal physiology during the neonatal period remains understudied. An MRI-based measure of tissue iron deposition, T2*, is a non-invasive way to probe striatal physiology neonatally, linked to dopaminergic processing and cognition in children and adults. Striatal subregions have distinct functions that may come online at different time periods in early life. To identify if there are critical periods before or after birth, we measured if striatal iron accrued with gestational age at birth [range=34.57-41.85 weeks] or postnatal age at scan [range=5-64 days], using MRI to probe the T2* signal in N=83 neonates in three striatal subregions. We found iron increased with postnatal age in the pallidum and putamen but not the caudate. No significant relationship between iron and gestational age was observed. Using a subset of infants scanned at preschool age (N=26), we show distributions of iron shift between timepoints. In infants, the pallidum had the least iron of the three regions but had the most by preschool age. Together, this provides evidence of distinct change for striatal subregions, a possible differentiation between motor and cognitive systems, identifying a mechanism that may impact future trajectories.

Highlights

Neonatal striatal tissue iron can be measured using the T2* signal from rsfMRInT2* changed with postnatal age in the pallidum and putamen but not in the caudatenT2* did not change with gestational age in any of the three regionsPatterns of iron deposition (nT2*) among regions shift from infancy to preschool.

Fetal inflammatory response and risk for psychiatric disorders

Inflammation contributes to numerous neuropsychiatric disorders, especially those that first appear in childhood. Maternal intrauterine environment, including the placenta, has a role in brain development and risk for neuropsychiatric disorders. This study examines the link between fetal inflammatory syndrome (FIRS), which is placental inflammation in the peri-partem period, and neuropsychiatric disorders during childhood.This is a retrospective cohort study using data from electronic medical records over a 19-year period at one women's hospital. The study includes 4851 children born with placentas meeting criteria for and 31,927 controls identified with normal placentas born during the same period. To be diagnosed with FIRS placenta must contain chorionic vasculitis and/or funisitis. Children had to be in study period for at least 5 years. The primary outcome of the study is incidence of neuropsychiatric disorders during childhood. The secondary outcomes were psychiatric medications prescribed, and psychiatric hospitalizations and treatment. Children born to placentas meeting criteria for FIRS were more likely to be diagnosed with neuropsychiatric disorders (OR = 1.21, CI 95% [1.09,1.35]). Specifically, they were more likely to be diagnosed with autism spectrum disorder (OR = 1.35, CI 95% [1.08, 1.67]), ADHD (OR = 1.27, CI 95% [1.07, 1.49]), conduct disorder (OR = 1.50, CI 95% [1.24, 1.81]), PTSD (OR = 2.46. CI 95% [1.21, 5.04]), adjusting for maternal history of psychiatric disorders, intra-partem substance use, and prescriptions of anti-inflammatory drugs. Children born with placental inflammation are at an increased risk to develop neuropsychiatric disorders. This has profound implications for future research, and early detection, monitoring, and treatment in these children.

Acute IL-6 exposure triggers canonical IL6Ra signaling in hiPSC microglia, but not neural progenitor cells

BACKGROUND

Prenatal exposure to elevated interleukin (IL)-6 levels is associated with increased risk for psychiatric disorders with a putative neurodevelopmental origin, such as schizophrenia (SZ), autism spectrum condition (ASC) and bipolar disorder (BD). Although rodent models provide causal evidence for this association, we lack a detailed understanding of the cellular and molecular mechanisms in human model systems. To close this gap, we characterized the response of human induced pluripotent stem cell (hiPSC-)derived microglia-like cells (MGL) and neural progenitor cells (NPCs) to IL-6 in monoculture.

RESULTS

We observed that human forebrain NPCs did not respond to acute IL-6 exposure in monoculture at both protein and transcript levels due to the absence of IL6R expression and soluble (s)IL6Ra secretion. By contrast, acute IL-6 exposure resulted in STAT3 phosphorylation and increased IL6, JMJD3 and IL10 expression in MGL, confirming activation of canonical IL6Ra signaling. Bulk RNAseq identified 156 up-regulated genes (FDR < 0.05) in MGL following acute IL-6 exposure, including IRF8, REL, HSPA1A/B and OXTR, which significantly overlapped with an up-regulated gene set from human post-mortem brain tissue from individuals with schizophrenia. Acute IL-6 stimulation significantly increased MGL motility, consistent with gene ontology pathways highlighted from the RNAseq data and replicating rodent model indications that IRF8 regulates microglial motility. Finally, IL-6 induces MGLs to secrete CCL1, CXCL1, MIP-1α/β, IL-8, IL-13, IL-16, IL-18, MIF and Serpin-E1 after 3 h and 24 h.

CONCLUSION

Our data provide evidence for cell specific effects of acute IL-6 exposure in a human model system, ultimately suggesting that microglia-NPC co-culture models are required to study how IL-6 influences human cortical neural progenitor cell development in vitro.

Intra-amniotic inflammation in the mid-trimester of pregnancy is a risk factor for neuropsychological disorders in childhood

OBJECTIVES

Intra-amniotic inflammation is a subclinical condition frequently caused by either microbial invasion of the amniotic cavity or sterile inflammatory stimuli, e.g., alarmins. An accumulating body of evidence supports a role for maternal immune activation in the genesis of fetal neuroinflammation and the occurrence of neurodevelopmental disorders such as cerebral palsy, schizophrenia, and autism. The objective of this study was to determine whether fetal exposure to mid-trimester intra-amniotic inflammation is associated with neurodevelopmental disorders in children eight to 12 years of age.

METHODS

This is a retrospective case-control study comprising 20 children with evidence of prenatal exposure to intra-amniotic inflammation in the mid-trimester and 20 controls matched for gestational age at amniocentesis and at delivery. Amniotic fluid samples were tested for concentrations of interleukin-6 and C-X-C motif chemokine ligand 10, for bacteria by culture and molecular microbiologic methods as well as by polymerase chain reaction for eight viruses. Neuropsychological testing of children, performed by two experienced psychologists, assessed cognitive and behavioral domains. Neuropsychological dysfunction was defined as the presence of an abnormal score (<2 standard deviations) on at least two cognitive tasks.

RESULTS

Neuropsychological dysfunction was present in 45% (9/20) of children exposed to intra-amniotic inflammation but in only 10% (2/20) of those in the control group (p=0.03). The relative risk (RR) of neuropsychological dysfunction conferred by amniotic fluid inflammation remained significant after adjusting for gestational age at delivery [aRR=4.5 (1.07-16.7)]. Of the 11 children diagnosed with neuropsychological dysfunction, nine were delivered at term and eight of them had mothers with intra-amniotic inflammation. Children exposed to intra-amniotic inflammation were found to have abnormalities in neuropsychological tasks evaluating complex skills, e.g., auditory attention, executive functions, and social skills, whereas the domains of reasoning, language, and memory were not affected in the cases and controls.

CONCLUSIONS

Asymptomatic sterile intra-amniotic inflammation in the mid-trimester of pregnancy, followed by a term birth, can still confer to the offspring a substantial risk for neurodevelopmental disorders in childhood. Early recognition and treatment of maternal immune activation in pregnancy may be a strategy for the prevention of subsequent neurodevelopmental disorders in offspring.

Racial differences in the associations between adiposity, placental growth hormone and inflammatory cytokines in pregnant women

Background

The prevalence of obesity among women of child-bearing age has contributed to an increased risk of pregnancy complications with a disproportional impact on women of lower socioeconomic status and among certain racial groups. In particular, socio-demographic and historical factors have resulted in higher rates of premature births and small-for-gestational age infants among Black women, which may be associated with placental function during pregnancy. The current study investigated the influence of maternal pre-pregnancy adiposity and race on the associations between inflammatory proteins, placental growth hormone (PGH), and infant birthweight. This information was collected for a subsample of 109 participants (Black, n = 39 vs. White, n = 70) from the Brain and Early Experiences (BEE) study.

Methods

Serum samples were acquired late in the second trimester to assess PGH levels, C-reactive protein (CRP), interleukin 6 (IL-6), interleukin 8 (IL-8), and interleukin-1 receptor antagonist (IL-1Ra). Participant questionnaire responses provided information on pre-pregnancy BMI, health, race, educational attainment, and infant birthweight. Bivariate correlations and multiple linear regression models were utilized to evaluate associations by race between preconception adiposity, inflammatory markers and PGH.

Results

After controlling for covariates including maternal age and education, gestational age, and fetal sex, regression models indicated that pre-pregnancy BMI was negatively associated with PGH (β=-0.42, p<0.05) and IL-8 was positively associated with PGH (β=0.35, p<0.05) among the Black mothers only; neither were significantly associated with PGH in the White mothers. When extending models to birth outcomes, BMI was positively associated with birthweight corrected for gestational age (BWz) (β=0.24, p<0.05) and educational attainment was negatively associated with BWz (β=0.28, p<0.05) for infants of White women. In contrast, neither variable was predictive of BWz for infants of Black mothers.

Conclusion

Future work is needed to investigate racial differences in the association between adiposity and placental functioning, which are likely to contribute to differential effects on pregnancy outcomes and fetal growth.

Altered dendritic morphology in dorsolateral prefrontal cortex of nonhuman primates prenatally exposed to maternal immune activation

Women who contract a viral or bacterial infection during pregnancy have an increased risk of giving birth to a child with a neurodevelopmental or psychiatric disorder. The effects of maternal infection are likely mediated by the maternal immune response, as preclinical animal models have confirmed that maternal immune activation (MIA) leads to long lasting changes in offspring brain and behavior development. The present study sought to determine the impact of MIA-exposure during the first or second trimester on neuronal morphology in dorsolateral prefrontal cortex (DLPFC) and hippocampus from brain tissue obtained from MIA-exposed and control male rhesus monkey (Macaca mulatta) during late adolescence. MIA-exposed offspring display increased neuronal dendritic branching in pyramidal cells in DLPFC infra- and supragranular layers relative to controls, with no significant differences observed between offspring exposed to maternal infection in the first and second trimester. In addition, the diameter of apical dendrites in DLPFC infragranular layer is significantly decreased in MIA-exposed offspring relative to controls, irrespective of trimester exposure. In contrast, alterations in hippocampal neuronal morphology of MIA-exposed offspring were not evident. These findings demonstrate that a maternal immune challenge during pregnancy has long-term consequences for primate offspring dendritic structure, selectively in a brain region vital for socioemotional and cognitive development.

Associations between the human immune system and gut microbiome with neurodevelopment in the first 5 years of life: A systematic scoping review

The aim of this review was to map the literature assessing associations between maternal or infant immune or gut microbiome biomarkers and child neurodevelopmental outcomes within the first 5 years of life. We conducted a PRISMA-ScR compliant review of peer-reviewed, English-language journal articles. Studies reporting gut microbiome or immune system biomarkers and child neurodevelopmental outcomes prior to 5 years were eligible. Sixty-nine of 23,495 retrieved studies were included. Of these, 18 reported on the maternal immune system, 40 on the infant immune system, and 13 on the infant gut microbiome. No studies examined the maternal microbiome, and only one study examined biomarkers from both the immune system and the gut microbiome. Additionally, only one study included both maternal and infant biomarkers. Neurodevelopmental outcomes were assessed from 6 days to 5 years. Associations between biomarkers and neurodevelopmental outcomes were largely nonsignificant and small in effect size. While the immune system and gut microbiome are thought to have interactive impacts on the developing brain, there remains a paucity of published studies that report biomarkers from both systems and associations with child development outcomes. Heterogeneity of research designs and methodologies may also contribute to inconsistent findings. Future studies should integrate data across biological systems to generate novel insights into the biological underpinnings of early development.

Maternal early life stress is associated with pro-inflammatory processes during pregnancy

Early life stress (ELS) is common in the United States and worldwide, and contributes to the development of psychopathology in individuals with these experiences and their offspring. A growing body of research suggests that early life stress may contribute to adverse health partly through modulation of immune (and particularly inflammatory) responses. Therefore, increased maternal prenatal inflammation has been proposed as a mechanistic pathway by which the observed cross-generational effects of parental early life stress on child neuropsychiatric outcomes may be exerted. We examined associations between early life stress and molecular markers of inflammation (specifically pro-inflammatory gene expression and receptor-mediated transcription factor activity) and a commonly studied circulating marker of inflammation (C-Reactive Protein) in a diverse group of women in or near their third trimester of pregnancy, covarying for age, race/ethnicity, BMI, concurrent infection, concurrent perceived stress, and per capita household income. Mothers who experienced higher levels of early life stress had significantly increased pro-inflammatory (NF-κB) and decreased anti-viral (IRF) transcription factor activity. Transcripts that were up or down regulated in mothers with high ELS were preferentially derived from both CD16+ and CD16- monocytes. Early life stress was not associated with elevated CRP. Taken together, these findings provide preliminary evidence for an association between ELS and a pro-inflammatory transcriptional phenotype during pregnancy that may serve as a mechanistic pathway for cross-generational transmission of the effects of early life stress on mental and physical health.

Maternal pre-pregnancy body mass index is associated with newborn offspring hypothalamic mean diffusivity: a prospective dual-cohort study

BACKGROUND

An extensive body of animal literature supports the premise that maternal obesity during pregnancy can alter the development of the fetal hypothalamus (HTH, a critical regulator of energy balance) with implications for offspring obesity risk (i.e., long-term energy imbalance). Yet, the relationship in humans between maternal overweight/obesity during pregnancy and fetal hypothalamic development remains largely unknown. Here, using an international (Finland and California, USA) multi-site diffusion tensor imaging (DTI) dataset, we test the hypothesis that maternal pre-pregnancy BMI is associated with newborn offspring HTH mean diffusivity (HTH MD, a replicable neural correlate of BMI in adults).

METHODS

HTH MD was independently quantified in two separate BMI-matched cohorts (up to class II obesity; BMIRange = 17-35) using a high-resolution atlas-based definition of HTH. A total of n = 231 mother-child dyads were available for this analysis (nSite,1 = 152, age at MRI = 26.7 ± 8.1 days, gestational age at birth = 39.9 ± 1.2 weeks, nM/F = 82/70, BMI = 24.2 ± 3.8; nSite,2 = 79, age at MRI = 25.6 ± 12.5 days, gestational age at birth = 39.3 ± 1.5 weeks, nM/F = 45/34, BMI = 25.1 ± 4.0). The association between maternal pre-pregnancy BMI and newborn offspring HTH MD was examined separately in each cohort using linear regression adjusting for gestational age at birth, postnatal age at scan, sex, whole white matter mean diffusivity, and DTI quality control criteria. In post hoc analyses, additional potentially confounding factors including socioeconomic status, ethnicity, and obstetric risk were adjusted where appropriate.

RESULTS

The distribution of maternal pre-pregnancy BMI was comparable across sites but differed by ethnicity and socioeconomic status. A positive linear association between maternal pre-pregnancy BMI and newborn offspring HTH MD was observed at both sites ([Formula: see text]Site,1 = 0.17, pSite,1 = 0.01; [Formula: see text]Site,2 = 0.22, pSite,2 = 0.03) and remained significant after adjusting for cohort-relevant covariates.

CONCLUSIONS

These findings translate the preclinically established association between maternal obesity during pregnancy and offspring hypothalamic microstructure to the human context. In addition to further replication/generalization, future efforts to identify biological mediators of the association between maternal obesity and fetal HTH development are warranted to develop targeted strategies for the primary prevention of childhood obesity.

Risk of attention deficit hyperactivity and autism spectrum disorders among the children of parents with autoimmune diseases: a nationwide birth cohort study

Studies have suggested that maternal autoimmune diseases are associated with an increased risk of attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD). However, research on the association of paternal autoimmune diseases with ADHD and ASD risk has remained inconclusive. Using the Taiwan National Health Insurance Research Database, we selected 708,517 family triads (father-mother-child) between 2001 and 2008 and followed them until the end of 2011. Parental autoimmune diseases as well as ADHD and ASD in children were identified during the study period. Increased ADHD risk in children in terms of hazard ratios (HRs) and 95% confidence intervals (CIs) was associated with prenatal exposure to paternal autoimmune diseases, including Sjögren's syndrome (HR: 8.41, 95% CI: 2.72-26.05), psoriasis (HR: 1.95, 95% CI: 1.05-3.63), and ankylosing spondylitis (HR: 2.02, 95% CI: 1.29-2.15), as well as maternal autoimmune diseases, such as systemic lupus erythematosus (HR: 1.53, 95% CI: 1.09-2.15), type 1 diabetes mellitus (HR: 1.55, 95% CI: 1.02-2.36), inflammatory bowel disease (HR: 2.37, 95% CI: 1.59-3.52), psoriasis (HR: 1.70, 95% CI: 1.00-2.87), and ankylosing spondylitis (HR: 2.07, 95% CI: 1.11-3.86). However, ASD was only associated with paternal inflammatory bowel disease (HR: 3.08, 95% CI: 1.15-8.28) and ankylosing spondylitis (HR: 2.65, 95% CI: 1.10-6.39). Both paternal and maternal autoimmune diseases were associated with increased likelihood of ADHD in children. However, only paternal autoimmune diseases were related to offspring ASD risk. The precise pathomechanism underlying the correlation between parental autoimmunity and child neurodevelopment requires further investigation.

Maternal pre-eclampsia serum increases neurite growth and mitochondrial function through a potential IL-6-dependent mechanism in differentiated SH-SY5Y cells

Introduction: Pre-eclampsia (PE) is a common and serious hypertensive disorder of pregnancy, which affects 3%-5% of first-time pregnancies and is a leading cause of maternal and neonatal morbidity and mortality. Prenatal exposure to PE is associated with an increased risk of neurodevelopmental disorders in affected offspring, although the cellular and molecular basis of this increased risk is largely unknown. Methods: Here, we examined the effects of exposure to maternal serum from women with PE or a healthy uncomplicated pregnancy on the survival, neurite growth and mitochondrial function of neuronally differentiated human SH-SY5Y neuroblastoma cells, which are commonly used to study neurite growth. Neurite growth and mitochondrial function are two strongly linked neurodevelopmental parameters in which alterations have been implicated in neurodevelopmental disorders. Following this, we investigated the pleiotropic cytokine interleukin-6 (IL-6) levels as a potential mechanism. Results: Cells exposed to 3% (v/v) PE serum for 72 h exhibited increased neurite growth (p < 0.05), which was validated in the human neural progenitor cell line, ReNcell^® VM (p < 0.01), and mitochondrial respiration (elevated oxygen consumption rate (p < 0.05), basal mitochondrial respiration, proton leak, ATP synthesis, and non-mitochondrial respiration) compared to control serum-treated cells. ELISA analysis showed elevations in maternal IL-6 in PE sera (p < 0.05) and placental explants (p < 0.05). In support of this, SH-SY5Y cells exposed to 3% (v/v) PE serum for 24 h had increased phospho-STAT3 levels, which is a key intracellular mediator of IL-6 signalling (p < 0.05). Furthermore, treatment with anti-IL-6 neutralizing antibody blocked the effects of PE serum on neurite growth (p < 0.05), and exposure to IL-6 promoted neurite growth in SH-SY5Y cells (p < 0.01). Discussion: Collectively these data show elevated serum levels of maternal IL-6 in PE, which increases neurite growth and mitochondrial function in SH-SY5Y cells. This rationalizes the further study of IL-6 as a potential mediator between PE exposure and neurodevelopmental outcome in the offspring.