Chronic maternal interleukin-17 and autism-related cortical gene expression, neurobiology, and behavior

Embryo-restricted responses to maternal IL-17A promote neurodevelopmental disorders in mouse offspring

Prenatal imprinting to interleukin 17A (IL-17A) triggers behavioral disorders in offspring. However, reported models of maternal immune activation utilizing immunostimulants, lack specificity to elucidate the anatomical compartments of IL-17A's action and the distinct behavioral disturbances it causes. By combining transgenic IL-17A overexpression with maternal deficiency in its receptor, we established a novel model of prenatal imprinting to maternal IL-17A (acronym: PRIMA-17 model). This model allowed us to study prenatal imprinting established exclusively through embryo-restricted IL-17A responses. We demonstrated a transfer of transgenic IL-17A across the placental barrier, which triggered the development of selected behavioral deficits in mouse offspring. More specifically, embryonic responses to IL-17A resulted in communicative impairment in early-life measured by reduced numbers of nest retrieval calls. In adulthood, IL-17A-imprinted offspring displayed an increase in anxiety-like behavior. We advocate our PRIMA-17 model as a useful tool to study neurological deficits in mice.

SCUBE1 Promotes Gestational Diabetes Mellitus: A Bioinformatics and Experimental Investigation

Gestational diabetes mellitus (GDM) is one of the most common metabolic diseases in pregnant women, posing significant risks to the life and health of both mothers and fetuses. With improving living standards, the incidence of GDM is increasing rapidly. Therefore, understanding the underlying mechanism of GDM is of paramount importance. We downloaded two datasets from the Gene Expression Omnibus (GEO) database, containing sequencing data specifically related to "gestational diabetes" and "placenta". By merging these two datasets, a mRNA expression dataset was obtained and subjected to bioinformatics analyses. To screen out corresponding genes, differential analysis and weighted correlation network analysis (WGCNA) were carried out. Lasso, support vector machine and random forest analyses were subsequently performed for identifying key genes from the differentially expressed genes (DEGs) jointly screened out through differential analysis and WGCNA. Afterwards, immunoinfiltration and correlation analysis were performed to screen immune cells that play a role in disease progression and explore the correlation between the screened key genes and immune cells, after which Western Blot, quantitative real-time polymerase chain reaction, Immunohistochemistry, methyl thiazolyl tetrazolium, flow cytometry, scratch and Transwell assays were, respectively, performed for verification. For further verification, we found that the expression levels of MAP6D1 and SCUBE1 in embryonic tissues of GDM patients was higher compared to those of healthy pregnant women, which was consistent with the results of bioinformatics analysis. Consequently, SCUBE1 was selected for follow-up experiment. In order to explore the role of SCUBE1 in the development of GDM, we treated the trophoblastic cells HTR-8/SVneo with high glucose, and on this basis downregulated the expression of SCUBE1. Through further analysis, we observed that SCUBE1 had a role in reducing cell activity, migration and invasion, and promoting cell apoptosis. In summary, SCUBE1 promotes the development of GDM by increasing cell apoptosis and reducing cell activity, migration, and invasion.

Maternal immune activation alters the GABAergic system in the prefrontal cortex of female rat offspring: Role of interleukin-6

Maternal immune activation (MIA) induces long-term cognitive impairments by modulating the gamma-aminobutyric acid (GABA)ergic system. Experimental evidence suggests that maternal immune challenge with bacterial active ingredient lipopolysaccharide (LPS) reduces GABAergic tone in the offspring's prefrontal cortex. In this study, we aimed to assess whether interleukin-6 (IL-6) contributes to this reduced GABAergic system in the prefrontal cortex of juvenile offspring. Pregnant rats were given intraperitoneal injections of either LPS (100 µg/Kg) or a pyrogen-free saline solution in the absence or the presence of an IL-6 neutralizing antibody (IL-6Ab, 10 µg/Kg) on gestation day (GD) 15, GD17 and GD19. Parvalbumin and somatostatin GABAergic interneurons and the density of inhibitory synapses were monitored in 30-day-old male and female rat offspring using fluorescent immunohistochemistry. The expression levels of Cl- transporters (NKCC1 and KCC2) were assessed using western blotting. Prenatal LPS induced a significant reduction in the cell density of parvalbumin-containing interneurons in the prefrontal cortex of female but not male rat offspring. LPS-induced MIA led to a reduction in the expression levels of NKCC1 in the prefrontal cortices of both male and female offspring. These long-lasting impacts of the MIA were alleviated when the IL-6Ab was co-administered with LPS during pregnancy. This study shows that the GABAergic system in the prefrontal cortex of female rats is highly sensitive to prenatal immune challenges. These data pave the way for exploring the specific mechanism(s) underlying the sex-dependent effects of early-life immune challenges.

Anti-angiogenic mechanisms and serotonergic dysfunction in the Rgs2 knockout model for the study of psycho-obstetric risk

Psychiatric and obstetric diseases are growing threats to public health and share high rates of co-morbidity. G protein-coupled receptor signaling (e.g., vasopressin, serotonin) may be a convergent psycho-obstetric risk mechanism. Regulator of G Protein Signaling 2 (RGS2) mutations increase risk for both the gestational disease preeclampsia and for depression. We previously found preeclampsia-like, anti-angiogenic obstetric phenotypes with reduced placental Rgs2 expression in mice. Here, we extend this to test whether conserved cerebrovascular and serotonergic mechanisms are also associated with risk for neurobiological phenotypes in the Rgs2 KO mouse. Rgs2 KO exhibited anxiety-, depression-, and hedonic-like behaviors. Cortical vascular density and vessel length decreased in Rgs2 KO; cortical and white matter thickness and cell densities were unchanged. In Rgs2 KO, serotonergic gene expression was sex-specifically changed (e.g., cortical Htr2a, Maoa increased in females but all serotonin targets unchanged or decreased in males); redox-related expression increased in paraventricular nucleus and aorta; and angiogenic gene expression was changed in male but not female cortex. Whole-cell recordings from dorsal raphe serotonin neurons revealed altered 5-HT1A receptor-dependent inhibitory postsynaptic currents (5-HT1A-IPSCs) in female but not male KO neurons. Additionally, serotonin transporter blockade by the SSRI sertraline increased the amplitude and time-to-peak of 5-HT1A-IPSCs in KO neurons to a greater extent than in WT neurons in females only. These results demonstrate behavioral, cerebrovascular, and sertraline hypersensitivity phenotypes in Rgs2 KOs, some of which are sex-specific. Disruptions may be driven by vascular and cell stress mechanisms linking the shared pathogenesis of psychiatric and obstetric disease to reveal future targets.

Serum interleukin-17 A and homocysteine levels in children with autism

BACKGROUND

Autism Spectrum Disorder (ASD) is a neurodevelopmental condition that typically emerges early in childhood. This study aimed to explore the potential link between serum levels of vitamin B12 and homocysteine (Hcy) and the severity of ASD symptoms in children.

METHODS

In this study, 50 children diagnosed with ASD comprised the observation group, while 50 healthy children constituted the control group. Serum levels of IL-17 A, Hcy, folate, and vitamin B12 were compared between the study group and control group, as well as among children with different degrees of ASD severity. The correlation between the Childhood Autism Rating Scale (CARS) score and serum levels of IL-17 A, Hcy, folate, and vitamin B12 was examined. Additionally, the relationship between serum IL-17 A and Hcy levels and their association with the severity ASD were explored.

RESULTS

Compared to the control group, the observation group demonstrated elevated serum Hcy and IL-17 A levels alongside decreased folate and vitamin B12 levels. Individuals with severe ASD exhibited higher Hcy and IL-17 A levels but lower folate and vitamin B12 levels compared to those with mild to moderate ASD. The CARS score showed negative correlations with serum folate and vitamin B12 levels and positive correlations with serum IL-17 A and Hcy levels in ASD patients. Additionally, serum Hcy and IL-17 A levels were correlated with ASD severity.

CONCLUSION

Children diagnosed with ASD presented with reduced serum vitamin B12 levels and increased levels of Hcy, potentially contributing to the onset and severity of ASD.

The role of the placenta-brain axis in psychoneuroimmune programming

Gestational exposures have enduring impacts on brain and neuroimmune development and function. Perturbations of pregnancy leading to placental structure/function deficits, cell stress, immune activation, and endocrine changes (metabolic, growth factors, etc.) all increase neuropsychiatric risk in offspring. The existing literature links obstetric diseases with placental involvement to offspring neuroimmune outcomes and neurodevelopmental risk. Psychoneuroimmune outcomes in offspring brain include changes to microglia, cytokine/chemokine production, cell stress, and long-term immunoreactivity. These outcomes are altered by structural, anti-angiogenic/hypoxic, inflammatory, and metabolic diseases of the placenta. This fetal programming occurs via direct placental passage or production of factors which can act directly on fetal brain substrates, or indirectly via action of circulating factors on intermediates in the placenta. Placental neuroendocrine, vascular/angiogenic, immune, and extracellular vesicular mechanisms are detailed. These mechanisms interact within various placental and pregnancy conditions. An increased understanding of the placental origins of psychoneuroimmunology will yield dividends for human health. Identifying maternal and placental biomarkers for fetal neuroimmune health may also revolutionize early diagnosis and precision psychiatry, empowering patients to make the best healthcare decisions for their families. Targeting placental mechanisms may be a valuable approach for the prevention and mitigation of intergenerational, lifelong neuropathology.

A role for adverse childhood experiences and depression in preeclampsia

Introduction

Adverse childhood experiences (ACEs) are a measure of childhood adversity and are associated with life-long morbidity. The impacts of ACEs on peripartum health including preeclampsia, a common and dangerous hypertensive disorder of pregnancy, remain unclear, however. Therefore, we aimed to determine ACE association with peripartum psychiatric health and prevalence of preeclampsia using a case-control design.

Methods

Clinical data were aggregated and validated using a large, intergenerational knowledgebase developed at our institution. Depression symptoms were measured by standard clinical screeners: the Patient Health Questionnaire-9 (PHQ-9) and the Edinburgh Postnatal Depression Scale (EPDS). ACEs were assessed via survey. Scores were compared between participants with (N = 32) and without (N = 46) prior preeclampsia.

Results

Participants with ACE scores ≥4 had significantly greater odds of preeclampsia than those with scores ≤ 3 (adjusted odds ratio = 6.71, 95% confidence interval:1.13-40.00; p = 0.037). Subsequent speculative analyses revealed that increased odds of preeclampsia may be driven by increased childhood abuse and neglect dimensions of the ACE score. PHQ-9 scores (3.73 vs. 1.86, p = 0.03), EPDS scores (6.38 vs. 3.71, p = 0.01), and the incidence of depression (37.5% vs. 23.9%, p = 0.05) were significantly higher in participants with a history of preeclampsia versus controls.

Conclusions

Childhood sets the stage for life-long health. Our findings suggest that ACEs may be a risk factor for preeclampsia and depression, uniting the developmental origins of psychiatric and obstetric risk.

Evaluation of serum interleukin-17 A and interleukin-22 levels in pediatric patients with autism spectrum disorder: a pilot study

BACKGROUND

Many neurodevelopmental abnormalities are connected to autism spectrum disorder (ASD), which can result in inflammation and elevated cytokine levels due to immune system dysregulation. Interleukin (IL)-17 A and IL-22 have been linked to the regulation of host defense against pathogens at the barrier surface, the regeneration of injured tissue, and the integration of the neurological, endocrine, and immune systems. Several studies have investigated the possible connection between IL-17 A and ASD as well as the severity of behavioral symptoms, but few of them included IL-22.

OBJECTIVES

To measure serum levels of interleukin (IL)-17 A and IL-22 in children with ASD and to investigate their association with disease severity.

METHODS

This pilot study was performed on 24 children with ASD and 24 matched controls. Childhood Autism Rating Scale (CARS) assessed ASD severity, and serum levels of IL-17 A and IL-22 were assessed by enzyme-linked immunosorbent assay (ELISA).

RESULTS

In ASD patients, serum levels of IL-17 A and IL-22 showed a significant increase compared to controls (p-values < 0.001). We compared serum levels of IL-17 A and IL-22 according to the severity categories by CARS and could not find any significant differences (p-values > 0.05). Only IL-22 had a significant positive correlation with ASD severity by CARS scores.

CONCLUSIONS

Raised serum levels of IL-17 A and IL-22 are associated with ASD; only IL-22, not IL-17 A, is correlated with ASD severity. This finding proposes IL-22 as a possible future effective target for ASD treatment. To fully comprehend the significance of these cytokines in ASD and their possible effects on ASD diagnosis and treatment, more research on a wider scale is required.

Alpha-Synuclein Pre-Formed Fibrils Injected into Prefrontal Cortex Primarily Spread to Cortical and Subcortical Structures

BACKGROUND

Parkinson's disease dementia (PDD) and dementia with Lewy bodies (DLB) are characterized by diffuse spread of alpha-synuclein (α-syn) throughout the brain. Patients with PDD and DLB have a neuropsychological pattern of deficits that include executive dysfunction, such as abnormalities in planning, timing, working memory, and behavioral flexibility. The prefrontal cortex (PFC) plays a major role in normal executive function and often develops α-syn aggregates in DLB and PDD.

OBJECTIVE

To investigate the long-term behavioral and cognitive consequences of α-syn pathology in the cortex and characterize pathological spread of α-syn.

METHODS

We injected human α-syn pre-formed fibrils into the PFC of wild-type male mice. We then assessed the behavioral and cognitive effects between 12- and 21-months post-injection and characterized the spread of pathological α-syn in cortical, subcortical, and brainstem regions.

RESULTS

We report that PFC PFFs: 1) induced α-syn aggregation in multiple cortical and subcortical regions with sparse aggregation in midbrain and brainstem nuclei; 2) did not affect interval timing or spatial learning acquisition but did mildly alter behavioral flexibility as measured by intraday reversal learning; and 3) increased open field exploration.

CONCLUSIONS

This model of cortical-dominant pathology aids in our understanding of how local α-syn aggregation might impact some symptoms in PDD and DLB.

Microglia and Microbiome-Gut-Brain Axis

The mammalian gut contains a community of microorganisms called gut microbiome. The gut microbiome is integrated into mammalian physiology, contributing to metabolism, production of metabolites, and promoting immunomodulatory actions. Microglia, the brain's resident innate immune cells, play an essential role in homeostatic neurogenesis, synaptic remodeling, and glial maturation. Microglial dysfunction has been implicated in the pathogenesis of several neuropsychiatric disorders. Recent findings indicate that microglia are influenced by the gut microbiome and their derived metabolites throughout life. The pathways by which microbiota regulate microglia have only started to be understood, but this discovery has the potential to provide valuable insights into the pathogenesis of brain disorders associated with an altered microbiome. Here, we discuss the recent literature on the role of the gut microbiome in modulating microglia during development and adulthood and summarize the key findings on this bidirectional crosstalk in selected examples of neuropsychiatric and neurodegenerative disorders. We also highlight some current caveats and perspectives for the field.

Advances in the study of IL-17 in neurological diseases and mental disorders

Interleukin-17 (IL-17), a cytokine characteristically secreted by T helper 17 (Th17) cells, has attracted increasing attention in recent years because of its importance in the pathogenesis of many autoimmune or chronic inflammatory diseases. Recent studies have shown that neurological diseases and mental disorders are closely related to immune function, and varying degrees of immune dysregulation may disrupt normal expression of immune molecules at critical stages of neural development. Starting from relevant mechanisms affecting immune regulation, this article reviews the research progress of IL-17 in a selected group of neurological diseases and mental disorders (autism spectrum disorder, Alzheimer's disease, epilepsy, and depression) from the perspective of neuroinflammation and the microbiota-gut-brain axis, summarizes the commonalities, and provides a prospective outlook of target application in disease treatment.

Cytokine Dynamics in Autism: Analysis of BMAC Therapy Outcomes

Autism spectrum disorder (ASD) has recently been linked to neuroinflammation and an aberrant immune response within the central nervous system. The intricate relationship between immune response and ASD remains elusive, with a gap in understanding the connection between specific immune mechanisms and neural manifestations in autism. In this study, we employed a comprehensive statistical approach, fusing both overarching and granular methods to examine the concentration of 16 cytokines in the cerebrospinal fluid (CSF) across each autologous bone marrow aspirate concentrate (BMAC) intrathecal administration in 63 male and 17 female autism patients. Following a six-month period post the third administration, patients were stratified into three categories based on clinical improvement: Group 1- no/mild (28 subjects), Group 2-moderate (16 subjects), and Group 3-major improvement (15 subjects). Our integrated analysis revealed pronounced disparities in CSF cytokine patterns and clinical outcomes in autism subjects pre- and post-BMAC transplantation. Crucially, our results suggest that these cytokine profiles hold promise as predictive markers, pinpointing ASD individuals who might not exhibit notable clinical amelioration post-BMAC therapy.

Preeclampsia promotes autism in offspring via maternal inflammation and fetal NFκB signaling

Preeclampsia (PE) is a risk factor for autism spectrum disorder (ASD) in offspring. However, the exact mechanisms underlying the impact of PE on progeny ASD are not fully understood, which hinders the development of effective therapeutic approaches. This study shows the offspring born to a PE mouse model treated by Nω-nitro-L-arginine methyl ester (L-NAME) exhibit ASD-like phenotypes, including neurodevelopment deficiency and behavioral abnormalities. Transcriptomic analysis of the embryonic cortex and adult offspring hippocampus suggested the expression of ASD-related genes was dramatically changed. Furthermore, the level of inflammatory cytokines TNFα in maternal serum and nuclear factor kappa B (NFκB) signaling in the fetal cortex were elevated. Importantly, TNFα neutralization during pregnancy enabled to ameliorate ASD-like phenotypes and restore the NFκB activation level in the offspring exposed to PE. Furthermore, TNFα/NFκB signaling axis, but not L-NAME, caused deficits in neuroprogenitor cell proliferation and synaptic development. These experiments demonstrate that offspring exposed to PE phenocopies ASD signatures reported in humans and indicate therapeutic targeting of TNFα decreases the likelihood of bearing children with ASD phenotypes from PE mothers.

Analysis of potential biomarkers and immune infiltration in autism based on bioinformatics analysis

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder caused by both environmental and genetic factors. However, its etiology and pathogenesis remain unclear. The purpose of this study was to establish an immune-related diagnostic model for ASD using bioinformatics methods and to identify ASD biomarkers. Two ASD datasets, GSE18123 and GSE29691, were integrated into the gene expression Database to eliminate batch effects. 41 differentially expressed genes were identified by microarray data linear model (limma package). Based on the results of the immune infiltration analysis, we speculated that neutrophils, B cells naive, CD8+ T cells, and Tregs are potential core immune cells in ASD and participate in the occurrence of ASD. Finally, the differential genes and immune infiltration in ASD and non-ASD patients were compared, and the most relevant genes were selected to construct the first immune correlation prediction model of ASD. After the calculation, the model exhibited better accuracy. The calculations show that the model has good accuracy.

Mouse In Vivo Placental Targeted CRISPR Manipulation

The placenta is an essential organ that regulates and maintains mammalian development in utero. The placenta is responsible for the transfer of nutrients and waste between the mother and fetus and the production and delivery of growth factors and hormones. Placental genetic manipulations in mice are critical for understanding the placenta's specific role in prenatal development. Placental-specific Cre-expressing transgenic mice have varying effectiveness, and other methods for placental gene manipulation can be useful alternatives. This paper describes a technique to directly alter placental gene expression using CRISPR gene manipulation, which can be used to modify the expression of targeted genes. Using a relatively advanced surgical approach, pregnant dams undergo a laparotomy on embryonic day 12.5 (E12.5), and a CRISPR plasmid is delivered by a glass micropipette into the individual placentas. The plasmid is immediately electroporated after each injection. After dam recovery, the placentas and embryos can continue development until assessment at a later time point. The evaluation of the placenta and offspring after the use of this technique can determine the role of time-specific placental function in development. This type of manipulation will allow for a better understanding of how placental genetics and function impact fetal growth and development in multiple disease contexts.

Neonatal loss of FGFR2 in astroglial cells affects locomotion, sociability, working memory, and glia-neuron interactions in mice

Fibroblast growth factor receptor 2 (FGFR2) is almost exclusively expressed in glial cells in postnatal mouse brain, but its impact in glia for brain behavioral functioning is poorly understood. We compared behavioral effects from FGFR2 loss in both neurons and astroglial cells and from FGFR2 loss in astroglial cells by using either the pluripotent progenitor-driven hGFAP-cre or the tamoxifen-inducible astrocyte-driven GFAP-creERT2 in Fgfr2 floxed mice. When FGFR2 was eliminated in embryonic pluripotent precursors or in early postnatal astroglia, mice were hyperactive, and had small changes in working memory, sociability, and anxiety-like behavior. In contrast, FGFR2 loss in astrocytes starting at 8 weeks of age resulted only in reduced anxiety-like behavior. Therefore, early postnatal loss of FGFR2 in astroglia is critical for broad behavioral dysregulation. Neurobiological assessments demonstrated that astrocyte-neuron membrane contact was reduced and glial glutamine synthetase expression increased only by early postnatal FGFR2 loss. We conclude that altered astroglial cell function dependent on FGFR2 in the early postnatal period may result in impaired synaptic development and behavioral regulation, modeling childhood behavioral deficits like attention deficit hyperactivity disorder (ADHD).

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.

An integrated cytokine and kynurenine network as the basis of neuroimmune communication

Two of the molecular families closely associated with mediating communication between the brain and immune system are cytokines and the kynurenine metabolites of tryptophan. Both groups regulate neuron and glial activity in the central nervous system (CNS) and leukocyte function in the immune system, although neither group alone completely explains neuroimmune function, disease occurrence or severity. This essay suggests that the two families perform complementary functions generating an integrated network. The kynurenine pathway determines overall neuronal excitability and plasticity by modulating glutamate receptors and GPR35 activity across the CNS, and regulates general features of immune cell status, surveillance and tolerance which often involves the Aryl Hydrocarbon Receptor (AHR). Equally, cytokines and chemokines define and regulate specific populations of neurons, glia or immune system leukocytes, generating more specific responses within restricted CNS regions or leukocyte populations. In addition, as there is a much larger variety of these compounds, their homing properties enable the superimposition of dynamic variations of cell activity upon local, spatially limited, cell populations. This would in principle allow the targeting of potential treatments to restricted regions of the CNS. The proposed synergistic interface of 'tonic' kynurenine pathway affecting baseline activity and the superimposed 'phasic' cytokine system would constitute an integrated network explaining some features of neuroimmune communication. The concept would broaden the scope for the development of new treatments for disorders involving both the CNS and immune systems, with safer and more effective agents targeted to specific CNS regions.

Sex-specific association between placental inflammatory cytokine mRNA expression and preschoolers' behavioral development: The Ma'anshan birth cohort study

BACKGROUND

Placental inflammation may contribute to brain abnormalities and childhood neuropsychiatric disorders, but limited knowledge is available on the association of placental inflammatory cytokine levels and offspring's behavioral development. This study aimed to examine the sex-specific association between placental inflammatory cytokine mRNA expression and preschoolers' behavioral development.

METHODS

3474 pregnant women were recruited as the initial study population in the Ma'anshan birth cohort (MABC) study. Placentas (n = 2519) were collected during childbirth, and the mRNA expression of IL-8, IL-1β, CRP, TNF-α, IL-6, IL-10, and IL-4 was assessed. The Child Behavior Checklist 1.5-5 (CBCL 1.5-5) was used to assess children's behavioral development at 4 years old. A T-score ≥ 60 on summary scales or a score ≥ 65 on syndrome scales was regarded as the borderline clinical range. Multiple linear regression models and binary logistic regression models were applied to explore the sex-specific associations between placental inflammatory cytokines mRNA transcript levels and preschoolers' behavioral development.

RESULTS

Sex-specific associations between placental inflammatory cytokines mRNA expression and preschoolers' behavioral development were observed. There was a positive association between IL-8 and CBCL scores for boys on anxious/depressed problems, aggressive behaviors, externalizing problems and total problems. Logistic regression models showed that high levels of IL-8 were associated with a higher risk of girls' emotionally reactive problems and sleep problems compared to low/medium levels. High TNF-α was correlated with increased sleep problem scores in boys, and medium TNF-α (vs. low levels) was associated with an increased risk of girls' externalizing problems. Medium levels of CRP, IL-1β, and IL-6 were found to be associated with a decreased risk of girls' behavioral problems compared to low/high levels. For anti-inflammatory cytokines, medium IL-10 and IL-4 (vs. low levels) were observed to be associated with a lower risk of internalizing problems in boys and externalizing problems in girls, respectively. High IL-10 was correlated with decreased attention problem scores in boys.

CONCLUSION

This study indicates that placental inflammatory cytokine mRNA expression of IL-8, CRP, TNF-α, IL-1β, IL-4 and IL-10 may be associated with preschoolers' behavioral development in a sex-specific manner.

Placental dysfunction: The core mechanism for poor neurodevelopmental outcomes in the offspring of preeclampsia pregnancies

Preeclampsia (PE) is a leading condition threatening pregnant women and their offspring. The offspring of PE pregnancies have a high risk of poor neurodevelopmental outcomes and neuropsychological diseases later in life. However, the pathophysiology and pathogenesis of poor neurodevelopment remain undetermined. Abnormal placental functions are at the core of most PE cases, and recent research evidence supports that the placenta plays an important role in fetal brain development. Here, we summarize the relationship between abnormal fetal brain development and placental dysfunction in PE conditions, which include the dysfunction of nutrient and gas-waste exchange, impaired angiogenesis stimulation, abnormal neurotransmitter regulation, disrupted special protectors, and immune disorders. All these factors could lead to poor neurodevelopmental outcomes.

Aberrant IL-17 Levels in Rodent Models of Autism Spectrum Disorder: A Systematic Review

Autism spectrum disorder (ASD) is a heterogeneous neurodevelopmental disorder characterised by stereotyped behaviours, specific interests, and impaired communication skills. Elevated levels of pro-inflammatory cytokines, such as interleukin-17A (IL-17A or IL-17), have been implicated as part of immune alterations that may contribute to this outcome. In this context, rodent models have helped elucidate the role of T-cell activation and IL-17 secretion in the pathogenesis of ASD. Regarding the preclinical findings, the data available is contradictory in offspring but not in the pregnant dams, pointing to IL-17 as one of the main drivers of altered behaviour in some models ASD, whilst there are no alterations described in IL-17 levels in others. To address this gap in the literature, a systematic review of altered IL-17 levels in rodent models of ASD was conducted. In total, 28 studies that explored IL-17 levels were included and observed that this cytokine was generally increased among the different models of ASD. The data compiled in this review can help the choice of animal models to study the role of cytokines in the development of ASD, seeking a parallel with immune alterations observed in individuals with this condition.

Consequences of Viral Infection and Cytokine Production During Pregnancy on Brain Development in Offspring

Infections during pregnancy can seriously damage fetal neurodevelopment by aberrantly activating the maternal immune system, directly impacting fetal neural cells. Increasing evidence suggests that these adverse impacts involve alterations in neural stem cell biology with long-term consequences for offspring, including neurodevelopmental disorders such as autism spectrum disorder, schizophrenia, and cognitive impairment. Here we review how maternal infection with viruses such as Influenza A, Cytomegalovirus, and Zika during pregnancy can affect the brain development of offspring by promoting the release of maternal pro-inflammatory cytokines, triggering neuroinflammation of the fetal brain, and/or directly infecting fetal neural cells. In addition, we review insights into how these infections impact human brain development from studies with animal models and brain organoids. Finally, we discuss how maternal infection with SARS-CoV-2 may have consequences for neurodevelopment of the offspring.

Interleukin-17a Induces Neuronal Differentiation of Induced-Pluripotent Stem Cell-Derived Neural Progenitors From Autistic and Control Subjects

Prenatal exposure to maternal immune activation (MIA) has been suggested to increase the probability of autism spectrum disorder (ASD). Recent evidence from animal studies indicates a key role for interleukin-17a (IL-17a) in promoting MIA-induced behavioral and brain abnormalities reminiscent of ASD. However, it is still unclear how IL-17a acts on the human developing brain and the cell types directly affected by IL-17a signaling. In this study, we used iPSC-derived neural progenitor cells (NPCs) from individuals with ASD of known and unknown genetic cause as well as from neurotypical controls to examine the effects of exogenous IL-17a on NPC proliferation, migration and neuronal differentiation, and whether IL-17a and genetic risk factors for ASD interact exacerbating alterations in NPC function. We observed that ASD and control NPCs endogenously express IL-17a receptor (IL17RA), and that IL-17a/IL17RA activation modulates downstream ERK1/2 and mTORC1 signaling pathways. Exogenous IL-17a did not induce abnormal proliferation and migration of ASD and control NPCs but, on the other hand, it significantly increased the expression of synaptic (Synaptophysin-1, Synapsin-1) and neuronal polarity (MAP2) proteins in these cells. Also, as we observed that ASD and control NPCs exhibited similar responses to exogenous IL-17a, it is possible that a more inflammatory environment containing other immune molecules besides IL-17a may be needed to trigger gene-environment interactions during neurodevelopment. In conclusion, our results suggest that exogenous IL-17a positively regulates the neuronal differentiation of human NPCs, which may disturb normal neuronal and synaptic development and contribute to MIA-related changes in brain function and behavior.

Neuronal Cell Adhesion Molecules May Mediate Neuroinflammation in Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition characterized by restrictive and repetitive behaviors, alongside deficits in social interaction and communication. The etiology of ASD is largely unknown but is strongly linked to genetic variants in neuronal cell adhesion molecules (CAMs), cell-surface proteins that have important roles in neurodevelopment. A combination of environmental and genetic factors are believed to contribute to ASD pathogenesis. Inflammation in ASD has been identified as one of these factors, demonstrated through the presence of proinflammatory cytokines, maternal immune activation, and activation of glial cells in ASD brains. Glial cells are the main source of cytokines within the brain and, therefore, their activity is vital in mediating inflammation in the central nervous system. However, it is unclear whether the aforementioned neuronal CAMs are involved in modulating neuroimmune signaling or glial behavior. This review aims to address the largely unexplored role that neuronal CAMs may play in mediating inflammatory cascades that underpin neuroinflammation in ASD, primarily focusing on the Notch, nuclear factor-κB (NF-κB), and mitogen-activated protein kinase (MAPK) cascades. We will also evaluate the available evidence on how neuronal CAMs may influence glial activity associated with inflammation. This is important when considering the impact of environmental factors and inflammatory responses on ASD development. In particular, neural CAM1 (NCAM1) can regulate NF-κB transcription in neurons, directly altering proinflammatory signaling. Additionally, NCAM1 and contactin-1 appear to mediate astrocyte and oligodendrocyte precursor proliferation which can alter the neuroimmune response. Importantly, although this review highlights the limited information available, there is evidence of a neuronal CAM regulatory role in inflammatory signaling. This warrants further investigation into the role other neuronal CAM family members may have in mediating inflammatory cascades and would advance our understanding of how neuroinflammation can contribute to ASD pathology.

Maternal and Adult Interleukin-17A Exposure and Autism Spectrum Disorder

Epidemiological evidence in humans has suggested that maternal infections and maternal autoimmune diseases are involved in the pathogenesis of autism spectrum disorder. Animal studies supporting human results have shown that maternal immune activation causes brain and behavioral alterations in offspring. Several underlying mechanisms, including interleukin-17A imbalance, have been identified. Apart from the pro-inflammatory effects of interleukin-17A, there is also evidence to support the idea that it activates neuronal function and defines cognitive behavior. In this review, we examined the signaling pathways in both immunological and neurological contexts that may contribute to the improvement of autism spectrum disorder symptoms associated with maternal blocking of interleukin-17A and adult exposure to interleukin-17A. We first describe the epidemiology of maternal immune activation then focus on molecular signaling of the interleukin-17 family regarding its physiological and pathological roles in the embryonic and adult brain. In the future, it may be possible to use interleukin-17 antibodies to prevent autism spectrum disorder.

The Effects of Maternal Interleukin-17A on Social Behavior, Cognitive Function, and Depression-Like Behavior in Mice with Altered Kynurenine Metabolites

Viral infection and chronic maternal inflammation during pregnancy are correlated with a higher prevalence of autism spectrum disorder (ASD). However, the pathoetiology of ASD is not fully understood; moreover, the key molecules that can cross the placenta following maternal inflammation and contribute to the development of ASD have not been identified. Recently, the pro-inflammatory cytokine, interleukin-17A (IL-17A) was identified as a potential mediator of these effects. To investigate the impact of maternal IL-17A on offspring, C57BL/6J dams were injected with IL-17A-expressing plasmids via the tail vein on embryonic day 12.5 (E12.5), and maternal IL-17A was expressed continuously throughout pregnancy. By adulthood, IL-17A-injected offspring exhibited behavioral abnormalities, including social and cognitive defects. Additionally, maternal IL-17A promoted metabolism of the essential amino acid tryptophan, which produces several neuroactive compounds and may affect fetal neurodevelopment. We observed significantly increased levels of kynurenine in maternal serum and fetal plasma. Thus, we investigated the effects of high maternal concentration of kynurenine on offspring by continuously administering mouse dams with kynurenine from E12.5 during gestation. Obviously, maternal kynurenine administration rapidly increased kynurenine levels in the fetal plasma and brain, pointing to the ability of kynurenine to cross the placenta and change the KP metabolites which are affected as neuroactive compounds in the fetal brain. Notably, the offspring of kynurenine-injected mice exhibited behavioral abnormalities similar to those observed in offspring of IL-17A-conditioned mice. Several tryptophan metabolites were significantly altered in the prefrontal cortex of the IL-17A-conditioned and kynurenine-injected adult mice, but not in the hippocampus. Even though we cannot exclude the possibility or other molecules being related to ASD pathogenesis and the presence of a much lower degree of pathway activation, our results suggest that increased kynurenine following maternal inflammation may be a key factor in changing the balance of KP metabolites in fetal brain during neuronal development and represents a therapeutic target for inflammation-induced ASD-like phenotypes.

IL-17 in the Pathogenesis of Disease: Good Intentions Gone Awry

The IL-17 family is an evolutionarily old cytokine family consisting of six members (IL-17A through IL-17F). IL-17 family cytokines signal through heterodimeric receptors that include the shared IL-17RA subunit, which is widely expressed throughout the body on both hematopoietic and nonhematopoietic cells. The founding family member, IL-17A, is usually referred to as IL-17 and has received the most attention for proinflammatory roles in autoimmune diseases like psoriasis. However, IL-17 is associated with a wide array of diseases with perhaps surprisingly variable pathologies. This review focuses on recent advances in the roles of IL-17 during health and in disease pathogenesis. To decipher the functions of IL-17 in diverse disease processes it is useful to first consider the physiological functions that IL-17 contributes to health. We then discuss how these beneficial functions can be diverted toward pathogenic amplification of deleterious pathways driving chronic disease.

Altered offspring neurodevelopment in an arginine vasopressin preeclampsia model

Preeclampsia is a severe gestational hypertensive condition linked to child neuropsychiatric disorders, although underlying mechanisms are unclear. We used a recently developed, clinically relevant animal model of preeclampsia to assess offspring. C57BL/6J mouse dams were chronically infused with arginine vasopressin (AVP) or saline (24 ng/h) throughout pregnancy. Adult offspring were behaviorally tested (Y-maze, open field, rotarod, social approach, and elevated plus maze). Offspring brain was assessed histologically and by RNA sequencing. Preeclampsia-exposed adult males exhibited increased anxiety-like behavior and social approach while adult females exhibited impaired procedural learning. Adult AVP-exposed males had reduced total neocortical volume. Adult AVP-exposed females had increased caudate-putamen volume, increased caudate-putamen cell number, and decreased excitatory synapse density in hippocampal dentate gyrus (DG), CA1, and CA3. At postnatal day 7 (P7), AVP-exposed male and female offspring both had smaller neocortex. At P7, AVP-exposed males also had smaller caudate-putamen volume, while females had increased caudate-putamen volume relative to neocortical size. Similar to P7, E18 AVP-exposed offspring had smaller dorsal forebrain, mainly in reduced intermediate, subventricular, and ventricular zone volume, particularly in males. Decreased volume was not accounted for by cell size or cerebrovascular vessel diameter changes. E18 cortical RNAseq revealed 49 differentially-expressed genes in male AVP-exposed offspring, over-representing cytoplasmic translation processes. In females, 31 genes were differentially-expressed, over-representing collagen-related and epithelial regulation pathways. Gene expression changes in E18 AVP-exposed placenta indicated potential underlying mechanisms. Deficits in behavior and forebrain development in this AVP-based preeclampsia model were distinctly different in males and females, implicating different neurobiological bases.

Neurodevelopmental signatures of narcotic and neuropsychiatric risk factors in 3D human-derived forebrain organoids

It is widely accepted that narcotic use during pregnancy and specific environmental factors (e.g., maternal immune activation and chronic stress) may increase risk of neuropsychiatric illness in offspring. However, little progress has been made in defining human-specific in utero neurodevelopmental pathology due to ethical and technical challenges associated with accessing human prenatal brain tissue. Here we utilized human induced pluripotent stem cells (hiPSCs) to generate reproducible organoids that recapitulate dorsal forebrain development including early corticogenesis. We systemically exposed organoid samples to chemically defined "enviromimetic" compounds to examine the developmental effects of various narcotic and neuropsychiatric-related risk factors within tissue of human origin. In tandem experiments conducted in parallel, we modeled exposure to opiates (μ-opioid agonist endomorphin), cannabinoids (WIN 55,212-2), alcohol (ethanol), smoking (nicotine), chronic stress (human cortisol), and maternal immune activation (human Interleukin-17a; IL17a). Human-derived dorsal forebrain organoids were consequently analyzed via an array of unbiased and high-throughput analytical approaches, including state-of-the-art TMT-16plex liquid chromatography/mass-spectrometry (LC/MS) proteomics, hybrid MS metabolomics, and flow cytometry panels to determine cell-cycle dynamics and rates of cell death. This pipeline subsequently revealed both common and unique proteome, reactome, and metabolome alterations as a consequence of enviromimetic modeling of narcotic use and neuropsychiatric-related risk factors in tissue of human origin. However, of our 6 treatment groups, human-derived organoids treated with the cannabinoid agonist WIN 55,212-2 exhibited the least convergence of all groups. Single-cell analysis revealed that WIN 55,212-2 increased DNA fragmentation, an indicator of apoptosis, in human-derived dorsal forebrain organoids. We subsequently confirmed induction of DNA damage and apoptosis by WIN 55,212-2 within 3D human-derived dorsal forebrain organoids. Lastly, in a BrdU pulse-chase neocortical neurogenesis paradigm, we identified that WIN 55,212-2 was the only enviromimetic treatment to disrupt newborn neuron numbers within human-derived dorsal forebrain organoids. Cumulatively this study serves as both a resource and foundation from which human 3D biologics can be used to resolve the non-genomic effects of neuropsychiatric risk factors under controlled laboratory conditions. While synthetic cannabinoids can differ from naturally occurring compounds in their effects, our data nonetheless suggests that exposure to WIN 55,212-2 elicits neurotoxicity within human-derived developing forebrain tissue. These human-derived data therefore support the long-standing belief that maternal use of cannabinoids may require caution so to avoid any potential neurodevelopmental effects upon developing offspring in utero.

Developmental Exposure to Air Pollution, Cigarettes, and Lead: Implications for Brain Aging

Brain development is impaired by maternal exposure to airborne toxins from ambient air pollution, cigarette smoke, and lead. Shared postnatal consequences include gray matter deficits and abnormal behaviors as well as elevated blood pressure. These unexpectedly broad convergences have implications for later life brain health because these same airborne toxins accelerate brain aging. Gene-environment interactions are shown for ApoE alleles that influence the risk of Alzheimer disease. The multigenerational trace of these toxins extends before fertilization because egg cells are formed in the grandmaternal uterus. The lineage and sex-specific effects of grandmaternal exposure to lead and cigarettes indicate epigenetic processes of relevance to future generations from our current and recent exposure to airborne toxins.

Adult mouse hippocampal transcriptome changes associated with long-term behavioral and metabolic effects of gestational air pollution toxicity

Gestational exposure to air pollution increases the risk of autism spectrum disorder and cognitive impairments with unresolved molecular mechanisms. This study exposed C57BL/6J mice throughout gestation to urban-derived nanosized particulate matter (nPM). Young adult male and female offspring were studied for behavioral and metabolic changes using forced swim test, fat gain, glucose tolerance, and hippocampal transcriptome. Gestational nPM exposure caused increased depressive behaviors, decreased neurogenesis in the dentate gyrus, and increased glucose tolerance in adult male offspring. Both sexes gained fat and body weight. Gestational nPM exposure induced 29 differentially expressed genes (DEGs) in adult hippocampus related to cytokine production, IL17a signaling, and dopamine degradation in both sexes. Stratification by sex showed twofold more DEGs in males than females (69 vs 37), as well as male-specific enrichment of DEGs mediating serotonin signaling, endocytosis, Gαi, and cAMP signaling. Gene co-expression analysis (WCGNA) identified a module of 43 genes with divergent responses to nPM between the sexes. Chronic changes in 14 DEGs (e.g., microRNA9-1) were associated with depressive behaviors, adiposity and glucose intolerance. These genes enriched neuroimmune pathways such as HMGB1 and TLR4. Based on cerebral cortex transcriptome data of neonates, we traced the initial nPM responses of HMGB1 pathway. In vitro, mixed glia responded to 24 h nPM with lower HMGB1 protein and increased proinflammatory cytokines. This response was ameliorated by TLR4 knockdown. In sum, we identified transcriptional changes that could be associated with air pollution-mediated behavioral and phenotypic changes. These identified genes merit further mechanistic studies for therapeutic intervention development.