Therapeutic effects of nanosilibinin in valproic acid-zebrafish model of autism spectrum disorder: Focusing on Wnt signaling pathway and autism spectrum disorder-related cytokines

In this study, we delved into the intricate world of autism spectrum disorder (ASD) and its connection to the disturbance in the Wnt signaling pathway and immunological abnormalities. Our aim was to evaluate the impact of silibinin, a remarkable modulator of both the Wnt signaling pathway and the immune system, on the neurobehavioral and molecular patterns observed in a zebrafish model of ASD induced by valproic acid (VPA). Because silibinin is a hydrophobic molecule and highly insoluble in water, it was used in the form of silibinin nanoparticles (nanosilibinin, NS). After assessing survival, hatching rate, and morphology of zebrafish larvae exposed to different concentrations of NS, the appropriate concentrations were chosen. Then, zebrafish embryos were exposed to VPA (1 μM) and NS (100 and 200 μM) at the same time for 120 h. Next, anxiety and inattentive behaviors and the expression of CHD8, CTNNB, GSK3beta, LRP6, TNFalpha, IL1beta, and BDNF genes were assessed 7 days post fertilization. The results indicated that higher concentrations of NS had adverse effects on survival, hatching, and morphological development. The concentrations of 100 and 200 μM of NS could ameliorate the anxiety-like behavior and learning deficit and decrease ASD-related cytokines (IL1beta and TNFalpha) in VPA-treated larvae. In addition, only 100 μM of NS prevented raising the gene expression of Wnt signaling-related factors (CHD8, CTNNB, GSK3beta, and LRP6). In conclusion, NS treatment for the first 120 h showed therapeutic effect on an autism-like phenotype probably via reducing the expression of pro-inflammatory cytokines genes and changing the expression of Wnt signaling components genes.

Intrauterine position effects in a mouse model of maternal immune activation

Rodent models of maternal immune activation (MIA) are increasingly used as experimental tools in preclinical research of immune-mediated neurodevelopmental disorders and mental illnesses. Using a viral-like MIA model that is based on prenatal poly(I:C) exposure in mice, we have recently identified the existence of subgroups of MIA-exposed offspring that show dissociable behavioral, transcriptional, brain network and inflammatory profiles even under conditions of genetic homogeneity and identical MIA. Here, we tested the hypothesis that the intrauterine positions of fetuses, which are known to shape individual variability in litter-bearing mammals through variations in fetal hormone exposure, may contribute to the variable outcomes of MIA in mice. MIA was induced by maternal administration of poly(I:C) on gestation day 12 in C57BL/6N mice. Determining intrauterine positions using delivery by Cesarean section (C-section), we found that MIA-exposed offspring developing between female fetuses only (0M-MIA offspring) displayed significant deficits in sociability and sensorimotor gating at adult age, whereas MIA-exposed offspring developing between one or two males in utero (1/2M-MIA offspring) did not show the same deficits. These intrauterine position effects similarly emerged in male and female offspring. Furthermore, while MIA elevated fetal brain levels of pro- and anti-inflammatory cytokines independently of the precise intrauterine position and sex of adjacent fetuses during the acute phase, fetal brain levels of TNF-α remained elevated in 0M-MIA but not 1/2M-MIA offspring until the post-acute phase in late gestation. As expected, 1/2M offspring generally showed higher testosterone levels in the fetal brain during late gestation as compared to 0M offspring, confirming the transfer of testosterone from male fetuses to adjacent male or female fetuses. Taken together, our findings identify a novel source of within-litter variability contributing to heterogeneous outcomes of short- and long-term effects in a mouse model of MIA. In broader context, our findings highlight that individual differences in fetal exposure to hormonal and inflammatory signals may be a perinatal factor that shapes risk and resilience to MIA.

Immune Alterations in the Intrauterine Environment Shape Offspring Brain Development in a Sex-Specific Manner

Exposure to immune dysregulation in utero or in early life has been shown to increase risk for neuropsychiatric illness. The sources of inflammation can be varied, including acute exposures due to maternal infection or acute stress, or persistent exposures due to chronic stress, obesity, malnutrition, or autoimmune diseases. These exposures may cause subtle alteration in brain development, structure, and function that can become progressively magnified across the life span, potentially increasing the likelihood of developing a neuropsychiatric conditions. There is some evidence that males are more susceptible to early-life inflammatory challenges than females. In this review, we discuss the various sources of in utero or early-life immune alteration and the known effects on fetal development with a sex-specific lens. To do so, we leveraged neuroimaging, behavioral, cellular, and neurochemical findings. Gaining clarity about how the intrauterine environment affects offspring development is critically important for informing preventive and early intervention measures that may buffer against the effects of these early-life risk factors.

In Utero Exposure to Maternal COVID-19 Vaccination and Offspring Neurodevelopment at 12 and 18 Months

Importance

Uptake of COVID-19 vaccines among pregnant individuals was hampered by safety concerns around potential risks to unborn children. Data clarifying early neurodevelopmental outcomes of offspring exposed to COVID-19 vaccination in utero are lacking.

Objective

To determine whether in utero exposure to maternal COVID-19 vaccination was associated with differences in scores on the Ages and Stages Questionnaire, third edition (ASQ-3), at 12 and 18 months of age.

Design, Setting, and Participants

This prospective cohort study, Assessing the Safety of Pregnancy During the Coronavirus Pandemic (ASPIRE), enrolled pregnant participants from May 2020 to August 2021; follow-up of children from these pregnancies is ongoing. Participants, which included pregnant individuals and their offspring from all 50 states, self-enrolled online. Study activities were performed remotely.

Exposure

In utero exposure of the fetus to maternal COVID-19 vaccination during pregnancy was compared with those unexposed.

Main Outcomes and Measures

Neurodevelopmental scores on validated ASQ-3, completed by birth mothers at 12 and 18 months. A score below the established cutoff in any of 5 subdomains (communication, gross motor, fine motor, problem solving, social skills) constituted an abnormal screen for developmental delay.

Results

A total of 2487 pregnant individuals (mean [SD] age, 33.3 [4.2] years) enrolled at less than 10 weeks' gestation and completed research activities, yielding a total of 2261 and 1940 infants aged 12 and 18 months, respectively, with neurodevelopmental assessments. In crude analyses, 471 of 1541 exposed infants (30.6%) screened abnormally for developmental delay at 12 months vs 203 of 720 unexposed infants (28.2%; χ2 = 1.32; P = .25); the corresponding prevalences at 18 months were 262 of 1301 (20.1%) vs 148 of 639 (23.2%), respectively (χ2 = 2.35; P = .13). In multivariable mixed-effects logistic regression models adjusting for maternal age, race, ethnicity, education, income, maternal depression, and anxiety, no difference in risk for abnormal ASQ-3 screens was observed at either time point (12 months: adjusted risk ratio [aRR], 1.14; 95% CI, 0.97-1.33; 18 months: aRR, 0.88; 95% CI, 0.72-1.07). Further adjustment for preterm birth and infant sex did not affect results (12 months: aRR, 1.16; 95% CI, 0.98-1.36; 18 months: aRR, 0.87; 95% CI, 0.71-1.07).

Conclusions and Relevance

Results of this cohort study suggest that COVID-19 vaccination was safe during pregnancy from the perspective of infant neurodevelopment to 18 months of age. Additional longer-term research should be conducted to corroborate these findings and buttress clinical guidance with a strong evidence base.

Dominance of Pro-Inflammatory Cytokines Over Anti-Inflammatory Ones in Placental Bed of Creta Cases

Objective

The objective of the study is to investigate changes occurring in key inflammatory cytokines at molecular level (including genetic and protein) in placental bed of placenta creta compared to that of normal placenta and their correlation to interstitial extravillous trophoblasts (EVT) number.

Subjects and Methods

Case-control study including placentas of patients with invasive placentation (creta placentas, n = 19) compared with those of normal placentation (n = 19). Besides routine histology and immunocytochemistry detection (cytokeratin-7 [CK-7]), addition to biochemical evaluation of expression of various cytokines including tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), IL6, IL-1RA, IL-8, IL-10, and IL-13 was carried out.

Results

Routine histological examination of placentas of creta cases revealed CK-7+ extravillous trophoblasts (EVT) penetrating deeply the myometrium with various histopathological arrangements and trophoblastic vascular invasion of the deep myometrial blood vessels. A significant increase (P < 0.05) in the mRNA expression of TNF-α, IL-1 β, and IL6 with an insignificant decrease in placental bed IL-1RA, IL-8, IL-10, and IL-13 was observed in creta cases compared to the control ones. A corresponding significant increase was detected in the protein levels of TNF-α, IL-1 β, and IL-6 as well as an insignificant decrease in placental bed IL-1RA, IL-8, IL-10, and IL-13 in creta cases compared to the normal ones. Moreover, we displayed a significant positive correlation (P < 0.05) between interstitial EVT number and mRNA expression of almost all pro-inflammatory cytokines with negative but insignificant correlation with anti-inflammatory cytokines in creta cases.

Conclusion

The upregulated pro-inflammatory cytokines and the correlation of their expression with the increased interstitial EVT provide a supporting evidence of their potentially more relevant role in the development of placenta creta than the anti-inflammatory ones.

The early life exposome and autism risk: a role for the maternal microbiome?

Autism spectrum disorders (ASD) are highly heritable, heterogeneous neurodevelopmental disorders characterized by clinical presentation of atypical social, communicative, and repetitive behaviors. Over the past 25 years, hundreds of ASD risk genes have been identified. Many converge on key molecular pathways, from translational control to those regulating synaptic structure and function. Despite these advances, therapeutic approaches remain elusive. Emerging data unearthing the relationship between genetics, microbes, and immunity in ASD suggest an integrative physiology approach could be paramount to delivering therapeutic breakthroughs. Indeed, the advent of large-scale multi-OMIC data acquisition, analysis, and interpretation is yielding an increasingly mechanistic understanding of ASD and underlying risk factors, revealing how genetic susceptibility interacts with microbial genetics, metabolism, epigenetic (re)programming, and immunity to influence neurodevelopment and behavioral outcomes. It is now possible to foresee exciting advancements in the treatment of some forms of ASD that could markedly improve quality of life and productivity for autistic individuals. Here, we highlight recent work revealing how gene X maternal exposome interactions influence risk for ASD, with emphasis on the intrauterine environment and fetal neurodevelopment, host-microbe interactions, and the evolving therapeutic landscape for ASD.

Sex-Specific Dysconnective Brain Injuries and Neuropsychiatric Conditions such as Autism Spectrum Disorder Caused by Group B Streptococcus-Induced Chorioamnionitis

Global health efforts have increased against infectious diseases, but issues persist with pathogens like Group B Streptococcus (GBS). Preclinical studies have elaborated on the mechanistic process of GBS-induced chorioamnionitis and its impact on the fetal programming of chronic neuropsychiatric diseases. GBS inoculation in rodents demonstrated the following: (i) silent and self-limited placental infection, similar to human chorioamnionitis; (ii) placental expression of chemokines attracting polymorphonuclear (PMN) cells; (iii) in vitro cytokine production; (iv) PMN infiltration in the placenta (histologic hallmark of human chorioamnionitis), linked to neurobehavioral impairments like cerebral palsy and autism spectrum disorders (ASD); (v) upregulation of interleukin-1β (IL-1β) in the placenta and fetal blood, associated with higher ASD risk in humans; (vi) sex-specific effects, with higher IL-1β release and PMN recruitment in male placenta; (vii) male offspring exhibiting ASD-like traits, while female offspring displayed attention deficit and hyperactivity disorder (ADHD)-like traits; (viii) IL-1 and/or NF-kB blockade alleviate placental and fetal inflammation, as well as subsequent neurobehavioral impairments. These findings offer potential therapeutic avenues, including sex-adapted anti-inflammatory treatment (e.g., blocking IL-1; repurposing of FDA-approved IL-1 receptor antagonist (IL-1Ra) treatment). Blocking the IL-1 pathway offers therapeutic potential to alleviate chorioamnionitis-related disabilities, presenting an opportunity for a human phase II RCT that uses IL-1 blockade added to the classic antibiotic treatment of chorioamnionitis.

The eNAMPT/TLR4 inflammatory cascade drives the severity of intra-amniotic inflammation in pregnancy and predicts infant outcomes

Introduction: Intra-amniotic inflammation (IAI) or chorioamnionitis is a common complication of pregnancy producing significant maternal morbidity/mortality, premature birth and neonatal risk of chronic lung diseases such as bronchopulmonary dysplasia (BPD). We examined eNAMPT (extracellular nicotinamide phosphoribosyltransferase), a critical inflammatory DAMP and TLR4 ligand, as a potential therapeutic target to reduce IAI severity and improve adverse fetal/neonatal outcomes. Methods: Blood/tissue samples were examined in: 1) women with histologically-proven chorioamnionitis, 2) very low birth weight (VLBW) neonates, and 3) a preclinical murine pregnancy model of IAI. Groups of pregnant IAI-exposed mice and pups were treated with an eNAMPT-neutralizing mAb. Results: Human placentas from women with histologically-proven chorioamnionitis exhibited dramatic NAMPT expression compared to placentas without chorioamnionitis. Increased NAMPT expression in whole blood from VLBW neonates (day 5) significantly predicted BPD development. Compared to untreated LPS-challenged murine dams (gestational day 15), pups born to eNAMPT mAb-treated dams (gestational days 15/16) exhibited a > 3-fold improved survival, reduced neonate lung eNAMPT/cytokine levels, and reduced development and severity of BPD and pulmonary hypertension (PH) following postnatal exposure to 100% hyperoxia days 1-14. Genome-wide gene expression studies of maternal uterine and neonatal cardiac tissues corroborated eNAMPT mAb-induced reductions in inflammatory pathway genes. Discussion: The eNAMPT/TLR4 inflammatory pathway is a highly druggable contributor to IAI pathobiology during pregnancy with the eNAMPT-neutralizing mAb a novel therapeutic strategy to decrease premature delivery and improve short- and long-term neonatal outcomes. eNAMPT blood expression is a potential biomarker for early prediction of chronic lung disease among premature neonates.

Epidural-related maternal fever: incidence, pathophysiology, outcomes, and management

Epidural-related maternal fever affects 15% to 25% of patients who receive a labor epidural. Two meta-analyses demonstrated that epidural-related maternal fever is a clinical phenomenon, which is unlikely to be caused by selection bias. All commonly used neuraxial techniques, local anesthetics with or without opioids, and maintenance regimens are associated with epidural-related maternal fever, however, the impact of each component is unknown. Two major theories surrounding epidural-related maternal fever development have been proposed. First, labor epidural analgesia may lead to the development of hyperthermia through a sterile (noninfectious) inflammatory process. This process may involve reduced activation of caspase-1 (a protease involved in cell apoptosis and activation of proinflammatory pathways) secondary to bupivacaine, which impairs the release of the antipyrogenic cytokine, interleukin-1-receptor antagonist, from circulating leucocytes. Detailed mechanistic processes of epidural-related maternal fever remain to be determined. Second, thermoregulatory mechanisms secondary to neuraxial blockade have been proposed, which may also contribute to epidural-related maternal fever development. Currently, there is no prophylactic strategy that can safely prevent epidural-related maternal fever from occurring nor can it easily be distinguished clinically from other causes of intrapartum fever, such as chorioamnionitis. Because intrapartum fever (of any etiology) is associated with adverse outcomes for both the mother and baby, it is important that all parturients who develop intrapartum fever are investigated and treated appropriately, irrespective of labor epidural utilization. Institution of treatment with appropriate antimicrobial therapy is recommended if an infectious cause of fever is suspected. There is currently insufficient evidence to warrant a change in recommendations regarding provision of labor epidural analgesia and the benefits of good quality labor analgesia must continue to be reiterated to expectant mothers.

Maternal immune activation impairs endocannabinoid signaling in the mesolimbic system of adolescent male offspring

Prenatal infections can increase the risk of developing psychiatric disorders such as schizophrenia in the offspring, especially when combined with other postnatal insults. Here, we tested, in a rat model of prenatal immune challenge by the viral mimic polyriboinosinic-polyribocytidilic acid, whether maternal immune activation (MIA) affects the endocannabinoid system and endocannabinoid-mediated modulation of dopamine functions. Experiments were performed during adolescence to assess i) the behavioral endophenotype (locomotor activity, plus maze, prepulse inhibition of startle reflex); ii) the locomotor activity in response to Δ9-Tetrahydrocannabinol (THC) and iii) the properties of ventral tegmental area (VTA) dopamine neurons in vivo and their response to THC; iv) endocannabinoid-mediated synaptic plasticity in VTA dopamine neurons; v) the expression of cannabinoid receptors and enzymes involved in endocannabinoid synthesis and catabolism in mesolimbic structures and vi) MIA-induced neuroinflammatory scenario evaluated by measurements of levels of cytokine and neuroinflammation markers. We revealed that MIA offspring displayed an altered locomotor activity in response to THC, a higher bursting activity of VTA dopamine neurons and a lack of response to cumulative doses of THC. Consistently, MIA adolescence offspring showed an enhanced 2-arachidonoylglycerol-mediated synaptic plasticity and decreased monoacylglycerol lipase activity in mesolimbic structures. Moreover, they displayed a higher expression of cyclooxygenase 2 (COX-2) and ionized calcium-binding adaptor molecule 1 (IBA-1), associated with latent inflammation and persistent microglia activity. In conclusion, we unveiled neurobiological mechanisms whereby inflammation caused by MIA influences the proper development of endocannabinoid signaling that negatively impacts the dopamine system, eventually leading to psychotic-like symptoms in adulthood.

Interleukin-1: an important target for perinatal neuroprotection?

Perinatal inflammation is a significant risk factor for lifelong neurodevelopmental impairments such as cerebral palsy. Extensive clinical and preclinical evidence links the severity and pattern of perinatal inflammation to impaired maturation of white and grey matters and reduced brain growth. Multiple pathways are involved in the pathogenesis of perinatal inflammation. However, studies of human and experimental perinatal encephalopathy have demonstrated a strong causative link between perinatal encephalopathy and excessive production of the pro-inflammatory effector cytokine interleukin-1. In this review, we summarize clinical and preclinical evidence that underpins interleukin-1 as a critical factor in initiating and perpatuating systemic and central nervous system inflammation and subsequent perinatal brain injury. We also highlight the important role of endogenous interleukin-1 receptor antagonist in mitigating interleukin-1-driven neuroinflammation and tissue damage, and summarize outcomes from clinical and mechanistic animal studies that establish the commercially available interleukin-1 receptor antagonist, anakinra, as a safe and effective therapeutic intervention. We reflect on the evidence supporting clinical translation of interleukin-1 receptor antagonist for infants at the greatest risk of perinatal inflammation and impaired neurodevelopment, and suggest a path to advance interleukin-1 receptor antagonist along the translational path for perinatal neuroprotection.

Limosilactobacillus reuteri normalizes blood-brain barrier dysfunction and neurodevelopment deficits associated with prenatal exposure to lipopolysaccharide

Maternal immune activation (MIA) derived from late gestational infection such as seen in chorioamnionitis poses a significantly increased risk for neurodevelopmental deficits in the offspring. Manipulating early microbiota through maternal probiotic supplementation has been shown to be an effective means to improve outcomes; however, the mechanisms remain unclear. In this study, we demonstrated that MIA modeled by exposing pregnant dams to lipopolysaccharide (LPS) induced an underdevelopment of the blood vessels, an increase in permeability and astrogliosis of the blood-brain barrier (BBB) at prewean age. The BBB developmental and functional deficits early in life impaired spatial learning later in life. Maternal Limosilactobacillus reuteri (L. reuteri) supplementation starting at birth rescued the BBB underdevelopment and dysfunction-associated cognitive function. Maternal L. reuteri-mediated alterations in β-diversity of the microbial community and metabolic responses in the offspring provide mechanisms and potential targets for promoting BBB integrity and long-term neurodevelopmental outcomes.

Alpinetin Suppresses Zika Virus-Induced Interleukin-1β Production and Secretion in Human Macrophages

Zika virus (ZIKV) infection has been recognized to cause adverse sequelae in the developing fetus. Specially, this virus activates the excessive release of IL-1β causing inflammation and altered physiological functions in multiple organs. Although many attempts have been invested to develop vaccine, antiviral, and antibody therapies, development of agents focusing on limiting ZIKV-induced IL-1β release have not gained much attention. We aimed to study the effects of alpinetin (AP) on IL-1β production in human macrophage upon exposure to ZIKV. Our study demonstrated that ZIKV stimulated IL-1β release in the culture supernatant of ZIKV-infected cells, and AP could effectively reduce the level of this cytokine. AP exhibited no virucidal activities against ZIKV nor caused alteration in viral production. Instead, AP greatly inhibited intracellular IL-1β synthesis. Surprisingly, this compound did not inhibit ZIKV-induced activation of NF-κB and its nuclear translocation. However, AP could significantly inhibit ZIKV-induced p38 MAPK activation without affecting the phosphorylation status of ERK1/2 and JNK. These observations suggest the possibility that AP may reduce IL-1β production, in part, through suppressing p38 MAPK signaling. Our current study sheds light on the possibility of using AP as an alternative agent for treating complications caused by ZIKV infection-induced IL-1β secretion.

P2X7 receptor as a potential therapeutic target for perinatal brain injury associated with preterm birth

Inflammation-induced preterm birth is the leading cause of perinatal mortality and long-term sequelae in surviving children. IL-1β is a major contributor to inflammation-induced preterm labor and its sequelae. It has recently been demonstrated that the cytokine storm and its progression depend on IL-1β release into circulation and that the P2X7 receptor (P2X7R) is the key player of the ATP-driven NLRP3/caspase-1 activation, necessary for the cleavage of pro-IL-1β to its mature form as well as its subsequent secretion. Being a key component to the inflammatory cascade, P2X7R illuminates a new therapeutic avenue to halt progression of inflammation prior to perinatal brain injury. In this review, we summarize the basic role of the P2X7 receptor in the inflammatory signaling cascade and the possibility of it being used as a therapeutic target in perinatal brain injury. We discuss the antagonists and agonists of the receptor as well as its role in other inflammatory diseases, showing the importance of discovering the functions of the receptor.

Associations Between Late Pregnancy Dietary Inflammatory Index (DII) and Offspring Bone Mass: A Meta-Analysis of the Southampton Women's Survey (SWS) and the Avon Longitudinal Study of Parents and Children (ALSPAC)

Systemic inflammation is associated with reduced bone mineral density and may be influenced by pro-inflammatory diets. We undertook an observational analysis of associations between late pregnancy energy-adjusted dietary inflammatory index (E-DII) scores and offspring bone outcomes in childhood. E-DII scores (higher scores indicating pro-inflammatory diets) were derived from food frequency questionnaires in late pregnancy in two prospective mother-offspring cohorts: the Southampton Women's Survey (SWS) and the Avon Longitudinal Study of Parents and Children (ALSPAC). The mean (SD) offspring age at dual-energy X-ray absorptiometry (DXA) scanning was 9.2 (0.2) years. Linear regression was used to assess associations between E-DII and bone outcomes, adjusting for offspring sex and age at DXA and maternal age at childbirth, educational level, pre-pregnancy body mass index (BMI), parity, physical activity level, and smoking in pregnancy. Associations were synthesized using fixed-effect meta-analysis. Beta coefficients represent the association per unit E-DII increment. In fully adjusted models (total n = 5910) late pregnancy E-DII was negatively associated with offspring whole body minus head bone area (BA: β = -3.68 [95% confidence interval -6.09, -1.27] cm2 /unit), bone mineral content (BMC: β = -4.16 [95% CI -6.70, -1.62] g/unit), and areal bone mineral density (aBMD: β = -0.0012 [95% CI -0.0020, -0.0004] g.cm-2 /unit), but there was only a weak association with BMC adjusted for BA (β = -0.48 [95% CI -1.11, 0.15] g/unit) at 9 years. Adjustment for child height partly or, for weight, fully attenuated the associations. Higher late pregnancy E-DII scores (representing a more pro-inflammatory diet) are negatively associated with offspring bone measures, supporting the importance of maternal and childhood diet on longitudinal offspring bone health. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

The impact of maternal high-fat diet on offspring neurodevelopment

A maternal high-fat diet affects offspring neurodevelopment with long-term consequences on their brain health and behavior. During the past three decades, obesity has rapidly increased in the whole human population worldwide, including women of reproductive age. It is known that maternal obesity caused by a high-fat diet may lead to neurodevelopmental disorders in their offspring, such as autism spectrum disorder, attention deficit hyperactivity disorder, anxiety, depression, and schizophrenia. A maternal high-fat diet can affect offspring neurodevelopment due to inflammatory activation of the maternal gut, adipose tissue, and placenta, mirrored by increased levels of pro-inflammatory cytokines in both maternal and fetal circulation. Furthermore, a maternal high fat diet causes gut microbial dysbiosis further contributing to increased inflammatory milieu during pregnancy and lactation, thus disturbing both prenatal and postnatal neurodevelopment of the offspring. In addition, global molecular and cellular changes in the offspring's brain may occur due to epigenetic modifications including the downregulation of brain-derived neurotrophic factor (BDNF) expression and the activation of the endocannabinoid system. These neurodevelopmental aberrations are reflected in behavioral deficits observed in animals, corresponding to behavioral phenotypes of certain neurodevelopmental disorders in humans. Here we reviewed recent findings from rodent models and from human studies to reveal potential mechanisms by which a maternal high-fat diet interferes with the neurodevelopment of the offspring.

Astrocytes and Microglia in Stress-Induced Neuroinflammation: The African Perspective

Background: Africa is laden with a youthful population, vast mineral resources and rich fauna. However, decades of unfortunate historical, sociocultural and leadership challenges make the continent a hotspot for poverty, indoor and outdoor pollutants with attendant stress factors such as violence, malnutrition, infectious outbreaks and psychological perturbations. The burden of these stressors initiate neuroinflammatory responses but the pattern and mechanisms of glial activation in these scenarios are yet to be properly elucidated. Africa is therefore most vulnerable to neurological stressors when placed against a backdrop of demographics that favor explosive childbearing, a vast population of unemployed youths making up a projected 42% of global youth population by 2030, repressive sociocultural policies towards women, poor access to healthcare, malnutrition, rapid urbanization, climate change and pollution. Early life stress, whether physical or psychological, induces neuroinflammatory response in developing nervous system and consequently leads to the emergence of mental health problems during adulthood. Brain inflammatory response is driven largely by inflammatory mediators released by glial cells; namely astrocytes and microglia. These inflammatory mediators alter the developmental trajectory of fetal and neonatal brain and results in long-lasting maladaptive behaviors and cognitive deficits. This review seeks to highlight the patterns and mechanisms of stressors such as poverty, developmental stress, environmental pollutions as well as malnutrition stress on astrocytes and microglia in neuroinflammation within the African context.

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.

Virus-Induced Maternal Immune Activation as an Environmental Factor in the Etiology of Autism and Schizophrenia

Maternal immune activation (MIA) is mediated by activation of inflammatory pathways resulting in increased levels of cytokines and chemokines that cross the placental and blood-brain barriers altering fetal neural development. Maternal viral infection is one of the most well-known causes for immune activation in pregnant women. MIA and immune abnormalities are key players in the etiology of developmental conditions such as autism, schizophrenia, ADHD, and depression. Experimental evidence implicating MIA in with different effects in the offspring is complex. For decades, scientists have relied on either MIA models or human epidemiological data or a combination of both. MIA models are generated using infection/pathogenic agents to induce an immunological reaction in rodents and monitor the effects. Human epidemiological studies investigate a link between maternal infection and/or high levels of cytokines in pregnant mothers and the likelihood of developing conditions. In this review, we discuss the importance of understanding the relationship between virus-mediated MIA and neurodevelopmental conditions, focusing on autism and schizophrenia. We further discuss the different methods of studying MIA and their limitations and focus on the different factors contributing to MIA heterogeneity.

COVID-19 in pregnancy: implications for fetal brain development

The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during pregnancy on the developing fetal brain is poorly understood. Other antenatal infections such as influenza have been associated with adverse neurodevelopmental outcomes in offspring. Although vertical transmission has been rarely observed in SARS-CoV-2 to date, given the potential for profound maternal immune activation (MIA), impact on the developing fetal brain is likely. Here we review evidence that SARS-CoV-2 and other viral infections during pregnancy can result in maternal, placental, and fetal immune activation, and ultimately in offspring neurodevelopmental morbidity. Finally, we highlight the need for cellular models of fetal brain development to better understand potential short- and long-term impacts of maternal SARS-CoV-2 infection on the next generation.

Differential effects of early or late exposure to prenatal maternal immune activation on mouse embryonic neurodevelopment

Exposure to maternal immune activation (MIA) in utero is a risk factor for neurodevelopmental and psychiatric disorders. MIA-induced deficits in adolescent and adult offspring have been well characterized; however, less is known about the effects of MIA exposure on embryo development. To address this gap, we performed high-resolution ex vivo MRI to investigate the effects of early (gestational day [GD]9) and late (GD17) MIA exposure on embryo (GD18) brain structure. We identify striking neuroanatomical changes in the embryo brain, particularly in the late-exposed offspring. We further examined the putative neuroanatomical underpinnings of MIA timing in the hippocampus using electron microscopy and identified differential effects due to MIA timing. An increase in apoptotic cell density was observed in the GD9-exposed offspring, while an increase in the density of neurons and glia with ultrastructural features reflective of increased neuroinflammation and oxidative stress was observed in GD17-exposed offspring, particularly in females. Overall, our findings integrate imaging techniques across different scales to identify differential impact of MIA timing on the earliest stages of neurodevelopment.

Differential Brain and Cerebrospinal Fluid Proteomic Responses to Acute Prenatal Endotoxin Exposure

Chorioamnionitis (CA) is a risk factor for preterm birth and is associated with neurodevelopmental delay and cognitive disorders. Prenatal inflammation-induced brain injury may resolve during the immediate postnatal period when rapid brain remodeling occurs. Cerebrospinal fluid (CSF) collected at birth may be a critical source of predictive biomarkers. Using pigs as a model of preterm infants exposed to CA, we hypothesized that prenatal lipopolysaccharide (LPS) exposure induces proteome changes in the CSF and brain at birth and postnatally. Fetal piglets (103 days gestation of full-term at 117 days) were administered intra-amniotic (IA) lipopolysaccharide (LPS) 3 days before preterm delivery by caesarian section. CSF and brain tissue were collected on postnatal Days 1 and 5 (P1 and P5). CSF and hippocampal proteins were profiled by LC-MS-based quantitative proteomics. Neuroinflammatory responses in the cerebral cortex, periventricular white matter and hippocampus were evaluated by immunohistochemistry, and gene expression was evaluated by qPCR. Pigs exposed to LPS in utero showed changes in CSF protein levels at birth but not at P5. Complement protein C3, hemopexin, vasoactive intestinal peptide, carboxypeptidase N subunit 2, ITIH1, and plasminogen expression were upregulated in the CSF, while proteins associated with axon growth and synaptic functions (FGFR1, BASP1, HSPD1, UBER2N, and RCN2), adhesion (talin1), and neuronal survival (Atox1) were downregulated. Microglia, but not astrocytes, were activated by LPS at P5 in the hippocampus but not in other brain regions. At this time, marginal increases in complement protein C3, LBP, HIF1a, Basp1, Minpp1, and FGFR1 transcription indicated hippocampal proinflammatory responses. In conclusion, few days exposure to endotoxin prenatally induce proteome changes in the CSF and brain at birth, but most changes resolve a few days later. The developing hippocampus has high neuronal plasticity in response to perinatal inflammation. Changes in CSF protein expression at birth may predict later structural brain damage in preterm infants exposed to variable types and durations of CA-related inflammation in utero.

Distinctive Neuroimaging Pattern in Term Newborns With Neonatal Placental Encephalopathy: A Case Series

BACKGROUND

Identifying antepartum versus intrapartum timing and the cause of neonatal encephalopathy (NE) often remains elusive owing to our limited understanding of the underlying pathophysiological processes and lack of appropriate biomarkers.

OBJECTIVES

This retrospective observational study describes a case series of term newborns with NE who displayed a recognizable magnetic resonance imaging pattern of immediately postnatal brain abnormalities that rapidly evolved toward cavitation. Our aim is to (1) report this neuroimaging pattern, (2) look for placental determinants, and (3) depict the outcome.

DESIGN/METHODS

This is a unicentric retrospective case series reporting the clinical, radiological, and laboratory findings of NE associated with a distinctive neuroimaging pattern, that is, immediately postnatal extensive corticosubcortical T2 hyperintensities, followed by rapid corticosubcortical cavitation that does not match the neuroimaging picture of intrapartum hypoxic-ischemic encephalopathy (HIE).

RESULTS

Seven term newborns presented bilateral corticosubcortical hyperintensities that were detected on T2 between day of life (DOL) 1-4, which rapidly evolved toward cystic encephalomalacia, that is, between DOL9 and DOL12. All these newborns presented with moderate/severe NE. The outcome was either neonatal death or quadriplegic cerebral palsy and epilepsy. None of the reported patients fulfilled the criteria of a high likelihood of acute intrapartum hypoxic-ischemic or quadriplegic cerebral palsy. All these newborns were exposed to chronic and/or acute placental inflammation and/or hypoxic-ischemic.

CONCLUSIONS

To further define the antepartum causes of NE, early neuroimaging and a placental examination are recommended. Brain T2 hyperintense injuries before DOL4 followed by rapid cavitation before DOL12 might be biomarkers of NE from an antepartum/placental origin.

Dendrimer-Based N-Acetyl Cysteine Maternal Therapy Ameliorates Placental Inflammation via Maintenance of M1/M2 Macrophage Recruitment

Intrauterine inflammation (IUI) is the primary cause of spontaneous preterm birth and predisposes neonates to long-term sequelae, including adverse neurological outcomes. N-acetyl-L-cysteine (NAC) is the amino acid L-cysteine derivative and a precursor to the antioxidant glutathione (GSH). NAC is commonly used clinically as an antioxidant with anti-inflammatory properties. Poor bioavailability and high protein binding of NAC necessitates the use of high doses resulting in side effects including nausea, vomiting, and gastric disruptions. Therefore, dendrimer-based therapy can specifically target the drug to the cells involved in inflammation, reducing side effects with efficacy at much lower doses than the free drug. Towards development of the new therapies for the treatment of maternal inflammation, we successfully administered dendrimer-based N-Acetyl Cysteine (DNAC) in an animal model of IUI to reduce preterm birth and perinatal inflammatory response. This study explored the associated immune mechanisms of DNAC treatment on placental macrophages following IUI, especially on M1/M2 type macrophage polarization. Our results demonstrated that intraperitoneal maternal DNAC administration significantly reduced the pro-inflammatory cytokine mRNA of Il1β and Nos2, and decreased CD45⁺ leukocyte infiltration in the placenta following IUI. Furthermore, we found that DNAC altered placental immune profile by stimulating macrophages to change to the M2 phenotype while decreasing the M1 phenotype, thus suppressing the inflammatory responses in the placenta. Our study provides evidence for DNAC therapy to alleviate IUI via the maintenance of macrophage M1/M2 imbalance in the placenta.

Interleukin-1 receptor antagonist, mode of analgesia and risk of Caesarean delivery after onset of labour: a Mendelian randomisation analysis

BACKGROUND

Lower circulating levels of the anti-inflammatory cytokine interleukin-1 receptor antagonist (IL-1ra) are associated with intrapartum inflammation and epidural analgesia-related maternal fever, both of which increase the rate of obstetric interventions. We hypothesised that genetic variants determining IL-1ra levels would be associated with Caesarean delivery rates after the onset of labour.

METHODS

We performed Mendelian randomisation analyses in parous women ≥16 yr old who received either non-neuraxial or neuraxial analgesia for their first two labours (UK Biobank). We used an established genetic score (calculated as 0-4, determined by the presence/absence of rs6743376 and rs1542176 alleles), in which the complete absence of both alleles causes the lowest IL-1ra levels. The primary outcome was Caesarean delivery after the onset of labour (odds ratio [OR]: 95% confidence intervals).

RESULTS

There were 7731 women (mean [standard deviation] age at first birth: 25 [5] yr) who had complete genetic scores and delivery data. For women who received non-neuraxial analgesia, Caesarean delivery rates were different across allele scores (χ²=12.4; P=0.015): 104/596 (17.4%) women with zero allele score underwent Caesarean delivery, compared with 654/5015 (13.0%) with allele score ≥1 (OR 1.41; 1.12-1.77). For women who had neuraxial analgesia, Caesarean delivery was not different across allele scores, ranging from 18.1% to 20.8% (χ²=0.29; P=0.99). Caesarean delivery was independent of type of analgesia for 818/7731 (10.6%) women with zero allele scores (OR 0.93; 0.63-1.39), but was higher in women receiving neuraxial analgesia with allele scores ≥1 (OR 1.55; 1.35-1.79; P<0.001).

CONCLUSIONS

Mendelian randomisation analysis suggests that higher IL-1ra levels are associated with reduced Caesarean delivery rate. Neuraxial analgesia appears to disrupt this link.

CLINICAL TRIAL REGISTRATION

UK Biobank study 62745.

Protective Effects of Interleukin-1 Blockade on Group B Streptococcus-Induced Chorioamnionitis and Subsequent Neurobehavioral Impairments of the Offspring

Group B Streptococcus (GBS) is one of the most common bacteria isolated in human chorioamnionitis. Placental infection due to GBS is a major risk factor for fetal organ injuries, preterm birth, perinatal morbidity and mortality, and life-long multiorgan morbidities. Preclinical and clinical studies have shown that GBS-induced infection drives polymorphonuclear (PMN) cell infiltration within the placenta, the hallmark of human chorioamnionitis. In preclinical and clinical studies, the upregulation of interleukin(IL)-1β in the placenta and maternal/fetal blood was associated with a high risk of neurodevelopmental impairments in the progeny. We hypothesized that targeted IL-1 blockade administered to the dam alleviates GBS-induced chorioamnionitis and the downstream fetal inflammatory response syndrome (FIRS). IL-1 receptor antagonist (IL-1Ra) improved the gestational weight gain of GBS-infected dams and did not worsen the infectious manifestations. IL-1Ra reduced the IL-1β titer in the maternal sera of GBS-infected dams. IL-1Ra decreased the levels of IL-1β, IL-6, chemokine (C-X-C motif) ligand 1 (CXCL1), and polymorphonuclear (PMN) infiltration in GBS-infected placenta. IL-1Ra treatment reduced the IL-1β titer in the fetal sera of GBS-exposed fetuses. IL-1 blockade also alleviated GBS-induced FIRS and subsequent neurobehavioral impairments of the offspring without worsening the outcome of GBS infection. Altogether, these results showed that IL-1 plays a key role in the physiopathology of live GBS-induced chorioamnionitis and consequent neurobehavioral impairments.

A Systematic Review of the Safety of Blocking the IL-1 System in Human Pregnancy

Blockade of the interleukin-1 (IL-1) pathway has been used therapeutically in several inflammatory diseases including arthritis and cryopyrin-associated periodic syndrome (CAPS). These conditions frequently affect women of childbearing age and continued usage of IL-1 specific treatments throughout pregnancy has been reported. IL-1 is involved in pregnancy complications and its blockade could have therapeutic potential. We systematically reviewed all reported cases of IL-1 blockade in human pregnancy to assess safety and perinatal outcomes. We searched several databases to find reports of specific blockade of the IL-1 pathway at any stage of pregnancy, excluding broad spectrum or non-specific anti-inflammatory intervention. Our literature search generated 2439 references of which 22 studies included, following extensive review. From these, 88 different pregnancies were assessed. Most (64.8%) resulted in healthy term deliveries without any obstetrical/neonatal complications. Including pregnancy exposed to Anakinra or Canakinumab, 12 (15.0%) resulted in preterm birth and one stillbirth occurred. Regarding neonatal complications, 2 cases of renal agenesis (2.5%) were observed, and 6 infants were diagnosed with CAPS (7.5%). In conclusion, this systematic review describes that IL-1 blockade during pregnancy is not associated with increased adverse perinatal outcomes, considering that treated women all presented an inflammatory disease associated with elevated risk of pregnancy complications.

Prenatal administration of IL-1Ra attenuate the neurodevelopmental impacts following non-pathogenic inflammation during pregnancy

Prenatal inflammation negatively affects placental function, subsequently altering fetal development. Pathogen-associated molecular patterns (PAMPs) are used to mimics infections in preclinical models but rarely detected during pregnancy. Our group previously developed an animal model of prenatal exposure to uric acid (endogenous mediator), leading to growth restriction alongside IL-1-driven placental inflammation (Brien et al. in J Immunol 198(1):443–451, 2017). Unlike PAMPs, the postnatal impact of prenatal non-pathogenic inflammation is still poorly understood. Therefore, we investigated the effects of prenatal uric acid exposure on postnatal neurodevelopment and the therapeutic potential of the IL-1 receptor antagonist; IL-1Ra. Uric acid induced growth restriction and placental inflammation, which IL-1Ra protected against. Postnatal evaluation of both structural and functional aspects of the brain revealed developmental changes. Both astrogliosis and microgliosis were observed in the hippocampus and white matter at postnatal day (PND)7 with IL-1Ra being protective. Decreased myelin density was observed at PND21, and reduced amount of neuronal precursor cells was observed in the Dentate Gyrus at PND35. Functionally, motor impairments were observed as evaluated with the increased time to fully turn upward (180 degrees) on the inclined plane and the pups were weaker on the grip strength test. Prenatal exposure to sterile inflammation, mimicking most clinical situation, induced growth restriction with negative impact on neurodevelopment. Targeted anti-inflammatory intervention prenatally could offer a strategy to protect brain development during pregnancy.

Inflammatory cytokines, placental pathology, and neurological outcomes in infants born to preterm preeclamptic mothers

Preeclampsia is both a vascular and inflammatory disorder. Since the placenta is a conduit for fetal development, preeclampsia should be a presumed cause of adverse infant outcomes. Yet, the relationship of placental pathology, inflammation and neurological outcomes after preeclampsia are understudied. We prospectively examined a cohort of maternal-infant dyads with preeclampsia for maternal inflammatory cytokines at time of preeclampsia diagnosis and delivery, and fetal cord blood cytokines (IL-1β, IL-6, IL-8, and TNF-α). Placentas were analyzed for inflammatory and vascular pathologies. Neurodevelopmental assessment of infants utilizing the Pediatric Stroke Outcome Measure (PSOM) was conducted at 6-month corrected gestational age. Eighty-one maternal-newborn dyads were examined. Worse neurological outcomes were not associated with elevated maternal / fetal cytokines. Early preterm birth (gestational age ≤ 32 weeks) was associated with worse neurological outcomes at 6-months regardless of maternal/ fetal cytokine levels, placental pathology, or cranial ultrasound findings (OR 1.70, [1.16-2.48], p = 0.006). When correcting for gestational age, elevated IL-6 approached significance as a predictor for worse developmental outcome (OR 1.025 [0.985-1.066], p = 0.221). Pathological evidence of maternal malperfusion and worse outcomes were noted in early preterm, although our sample size was small. Our study did not demonstrate an obvious association of inflammation and placental pathology in preeclampsia and adverse neurodevelopmental outcome at 6-month corrected age but does suggest maternal malperfusion at earlier gestational age may be a risk factor for worse outcome.

The Role of Maternal Immune Activation in the Pathogenesis of Autism: A Review of the Evidence, Proposed Mechanisms and Implications for Treatment

Autism spectrum disorder (ASD) is a neurodevelopmental disease that is characterized by a deficit in social interactions and communication, as well as repetitive and restrictive behaviors. Increasing lines of evidence suggest an important role for immune dysregulation and/or inflammation in the development of ASD. Recently, a relationship between inflammation, oxidative stress, and mitochondrial dysfunction has been reported in the brain tissue of individuals with ASD. Some recent studies have also reported oxidative stress and mitochondrial abnormalities in animal models of maternal immune activation (MIA). This review is focused on the hypothesis that MIA induces microglial activation, oxidative stress, and mitochondrial dysfunction, a deleterious trio in the brain that can lead to neuroinflammation and neurodevelopmental pathologies in offspring. Infection during pregnancy activates the mother’s immune system to release proinflammatory cytokines, such as IL-6, TNF-α, and others. Furthermore, these cytokines can directly cross the placenta and enter the fetal circulation, or activate resident immune cells, resulting in an increased production of proinflammatory cytokines, including IL-6. Proinflammatory cytokines that cross the blood–brain barrier (BBB) may initiate a neuroinflammation cascade, starting with the activation of the microglia. Inflammatory processes induce oxidative stress and mitochondrial dysfunction that, in turn, may exacerbate oxidative stress in a self-perpetuating vicious cycle that can lead to downstream abnormalities in brain development and behavior.

Lipopolysaccharide-induced maternal immune activation modulates microglial CX3CR1 protein expression and morphological phenotype in the hippocampus and dentate gyrus, resulting in cognitive inflexibility during late adolescence

Inflammation during pregnancy can disturb brain development and lead to disorders in the progeny, including autism spectrum disorder and schizophrenia. However, the mechanism by which a prenatal, short-lived increase of cytokines results in adverse neurodevelopmental outcomes remains largely unknown. Microglia-the brain's resident immune-cells-stand as fundamental cellular mediators, being highly sensitive and responsive to immune signals, which also play key roles during normal development. The fractalkine signaling axis is a neuron-microglia communication mechanism used to regulate neurogenesis and network formation. Previously, we showed hippocampal reduction of fractalkine receptor (Cx3cr1) mRNA at postnatal day (P) 15 in male offspring exposed to maternal immune activation induced with lipopolysaccharide (LPS) during late gestation, which was concomitant to an increased dendritic spine density in the dentate gyrus, a neurogenic niche. The current study sought to evaluate the origin and impact of this reduced hippocampal Cx3cr1 mRNA expression on microglia and cognition. We found that microglial total cell number and density are not affected in the dorsal hippocampus and dentate gyrus, respectively, but that the microglial CX3CR1 protein is decreased in the hippocampus of LPS-male offspring at P15. Further characterization of microglial morphology in the dentate gyrus identified a more ameboid phenotype in LPS-exposed offspring, predominantly in males, at P15. We thus explored maternal plasma and fetal brain cytokines to understand the mechanism behind microglial priming, showing a robust immune activation in the mother at 2 and 4 hrs after LPS administration, while only IL-10 tended towards upregulation at 2 hrs after LPS in fetal brains. To evaluate the functional long-term consequences, we assessed learning and cognitive flexibility behavior during late adolescence, finding that LPS affects only the latter with a male predominance on perseveration. A CX3CR1 gene variant in humans that results in disrupted fractalkine signaling has been recently associated with an increased risk for neurodevelopmental disorders. We show that an acute immune insult during late gestation can alter fractalkine signaling by reducing the microglial CX3CR1 protein expression, highlighting neuron-microglial fractalkine signaling as a relevant target underlying the outcomes of environmental risk factors on neurodevelopmental disorders.

Astroglial Hemichannels and Pannexons: The Hidden Link between Maternal Inflammation and Neurological Disorders

Maternal inflammation during pregnancy causes later-in-life alterations of the offspring’s brain structure and function. These abnormalities increase the risk of developing several psychiatric and neurological disorders, including schizophrenia, intellectual disability, bipolar disorder, autism spectrum disorder, microcephaly, and cerebral palsy. Here, we discuss how astrocytes might contribute to postnatal brain dysfunction following maternal inflammation, focusing on the signaling mediated by two families of plasma membrane channels: hemi-channels and pannexons. [Ca²⁺]_i imbalance linked to the opening of astrocytic hemichannels and pannexons could disturb essential functions that sustain astrocytic survival and astrocyte-to-neuron support, including energy and redox homeostasis, uptake of K⁺ and glutamate, and the delivery of neurotrophic factors and energy-rich metabolites. Both phenomena could make neurons more susceptible to the harmful effect of prenatal inflammation and the experience of a second immune challenge during adulthood. On the other hand, maternal inflammation could cause excitotoxicity by producing the release of high amounts of gliotransmitters via astrocytic hemichannels/pannexons, eliciting further neuronal damage. Understanding how hemichannels and pannexons participate in maternal inflammation-induced brain abnormalities could be critical for developing pharmacological therapies against neurological disorders observed in the offspring.

Human Placental Trophoblasts Infected by Listeria monocytogenes Undergo a Pro-Inflammatory Switch Associated With Poor Pregnancy Outcomes

The placenta controls the growth of the fetus and ensures its immune protection. Key to these functions, the syncytiotrophoblast (SYN) is a syncytium formed by fusion of underlying mononuclear trophoblasts. The SYN covers the placental surface and is bathed in maternal blood to mediate nutritional and waste exchanges between the mother and fetus. The bacterial pathogen Listeria monocytogenes breaches the trophoblast barrier and infects the placental/fetal unit resulting in poor pregnancy outcomes. In this work, we analyzed the L. monocytogenes intracellular lifecycle in primary human trophoblasts. In accordance with previous studies, we found that the SYN is 20-fold more resistant to infection compared to mononuclear trophoblasts, forming a protective barrier to infection at the maternal interface. We show for the first time that this is due to a significant reduction in L. monocytogenes uptake by the SYN rather than inhibition of the bacterial intracellular division or motility. We here report the first transcriptomic analysis of L. monocytogenes-infected trophoblasts (RNA sequencing). Pathway analysis showed that infection upregulated TLR2, NOD-like, and cytosolic DNA sensing pathways, as well as downstream pro-inflammatory circuitry (NF-κB, AP-1, IRF4, IRF7) leading to the production of mediators known to elicit the recruitment and activation of maternal leukocytes (IL8, IL6, TNFα, MIP-1). Signature genes associated with poor pregnancy outcomes were also upregulated upon infection. Measuring the release of 54 inflammatory mediators confirmed the transcriptomic data and revealed sustained production of tolerogenic factors (IL-27, IL-10, IL-1RA, TSLP) despite infection. Both the SYN and mononuclear trophoblasts produced cytokines, but surprisingly, some cytokines were predominantly produced by the SYN (IL-8, IL-6) or by non-fused trophoblasts (TNFα). Collectively, our data support that trophoblasts act as placental gatekeepers that limit and detect L. monocytogenes infection resulting in a pro-inflammatory response, which may contribute to the poor pregnancy outcomes if the pathogen persists.

The effects of antivenom administrations on the brain tissue of experimentally envenomed pregnant rats and their pups with Androctonus crassicauda scorpion venom during organogenesis period

This study aims to show the changing effects of Androctonus crassicauda venom and A. crasicauda specific antivenom during pregnancy in brain tissue of dams and their pups. Totally, 12 pregnant-Wistar Albino rats were randomly divided into two groups as venom-antivenom administration (n = 6) and control groups (n = 6). In venom-antivenom administration group (VAV), the sublethal dose of A. crassicauda venom dissolved in 1 mL physiological saline solution was subcutaneously (s.c.) injected into pregnant rats during organogenesis period (between 7 and 13 days of pregnancy). Four hours after each venom injection, 1 mL/s.c. dose of the specific anti-venom was administered to rats of VAV group. The rats in control group were given sterile saline solution 1 mL/s.c. In both groups, the fetuses were surgically delivered on the 21st day of pregnancy; dams and pups were sacrificed on postnatal 21 days, and their brain tissues were removed. The brain tissue of dams and their pups were evaluated histopathologically and immunohistochemically. To show the neuronal damages, 8-hydroxy-2-deoxyguanosine (8-OHDG) and amyloid beta precursor protein (ABPP) immunoexpressions were scored in cerebrum, cerebellum, pons and medulla oblongata of brain. To show the neuroprotection, reelin and beta-arrestin immunoexpressions were scored again in the same way. In this context, 8-OHDG immunoexpressions were increased in neocortex, hippocampus and nucleus accumbens when compared with that of control group. Amyloid beta precursor protein was negative in both groups. Reelin and beta-arrestin partly increased in fore and mid brain of VAV group as a reaction against neuronal damages when compared with that of control pups. The authors believe that prompt intervention using anti-venom to scorpion envenomation can partly stop neuronal damages. This neuroprotection may be increased to high and serial doses of anti-venom to save neonatal lives.

CCR2 mediates the adverse effects of LPS in the pregnant mouse

In our earlier work, we found that intrauterine (i.u.) and intraperitoneal (i.p.) injection of LPS (10-μg serotype 0111:B4) induced preterm labor (PTL) with high pup mortality, marked systemic inflammatory response and hypotension. Here, we used both i.u. and i.p. LPS models in pregnant wild-type (wt) and CCR2 knockout (CCR2-/-) mice on E16 to investigate the role played by the CCL2/CCR2 system in the response to LPS. Basally, lower numbers of monocytes and macrophages and higher numbers of neutrophils were found in the myometrium, placenta, and blood of CCR2-/- vs. wt mice. After i.u. LPS, parturition occurred at 14 h in both groups of mice. At 7 h post-injection, 70% of wt pups were dead vs. 10% of CCR2-/- pups, but at delivery 100% of wt and 90% of CCR2-/- pups were dead. Myometrial and placental monocytes and macrophages were generally lower in CCR2-/- mice, but this was less consistent in the circulation, lung, and liver. At 7 h post-LPS, myometrial ERK activation was greater and JNK and p65 lower and the mRNA levels of chemokines were higher and of inflammatory cytokines lower in CCR2-/- vs. wt mice. Pup brain and placental inflammation were similar. Using the IP LPS model, we found that all measures of arterial pressure increased in CCR2-/- but declined in wt mice. These data suggest that the CCL2/CCR2 system plays a critical role in the cardiovascular response to LPS and contributes to pup death but does not influence the onset of inflammation-induced PTL.

The anti-inflammatory role of placental Hofbauer cells is altered in patients with chorioamnionitis: Are CYP2C8 and soluble epoxide hydrolase involved in immunomodulation?

AIMS

Hofbauer cells (HBCs) are placental macrophages playing various roles during normal and complicated pregnancies, and of the latter, chorioamnionitis is the most frequent.

METHODS

In placenta with chorioamnionitis, we examined immunohistochemical expression profiles of IL-1β, IL-10, and their potential regulators, CYP2C8 and soluble epoxide hydrolase (sEH), in Hofbauer cells and compared the results with our previously published data for normal placenta.

RESULTS

We found that the expression profiles of the studied proteins in Hofbauer cells in chorioamnionitis differs from normal placenta. In chorioamnionitis, HBCs showed a moderate expression of IL-1β together with a weak expression of IL-10 and CYP2C8. Contrary to normal placenta, HBCs in chorioamnionitis express sEH. We demonstrated a moderate positive correlation between the expression of CYP2C8 and sEH in chorioamnionitis (Spearman r = 0.5654), suggesting enhanced degradation of anti-inflammatory epoxyeicosatrienoic acids. Moreover, the relations of IL-1β and IL-10 to CYP2C8, previously described in normal placenta, disappeared. Furthermore, a weak expression of anti-inflammatory IL-10 in chorioamnionitis was accompanied by change in circularity of HBCs (Spearman r = 0.8193).

CONCLUSION

Taken together, these findings suggest a possible alteration of the anti-inflammatory role of HBCs and its regulation in chorioamnionitis.

Anti-Inflammatory Therapies for Treatment of Inflammation-Related Preterm Brain Injury

Despite the prevalence of preterm brain injury, there are no established neuroprotective strategies to prevent or alleviate mild-to-moderate inflammation-related brain injury. Perinatal infection and inflammation have been shown to trigger acute neuroinflammation, including proinflammatory cytokine release and gliosis, which are associated with acute and chronic disturbances in brain cell survival and maturation. These findings suggest the hypothesis that the inhibition of peripheral immune responses following infection or nonspecific inflammation may be a therapeutic strategy to reduce the associated brain injury and neurobehavioral deficits. This review provides an overview of the neonatal immunity, neuroinflammation, and mechanisms of inflammation-related brain injury in preterm infants and explores the safety and efficacy of anti-inflammatory agents as potentially neurotherapeutics.

Hypoxia and oxidative stress induce sterile placental inflammation in vitro

Fetal growth restriction (FGR) and stillbirth are associated with placental dysfunction and inflammation and hypoxia, oxidative and nitrative stress are implicated in placental damage. Damage-associated molecular patterns (DAMPs) are elevated in pregnancies at increased risk of FGR and stillbirth and are associated with increase in pro-inflammatory placental cytokines. We hypothesised that placental insults lead to release of DAMPs, promoting placental inflammation. Placental tissue from uncomplicated pregnancies was exposed in vitro to hypoxia, oxidative or nitrative stress. Tissue production and release of DAMPs and cytokines was determined. Oxidative stress and hypoxia caused differential release of DAMPs including uric acid, HMGB1, S100A8, cell-free fetal DNA, S100A12 and HSP70. After oxidative stress pro-inflammatory cytokines (IL-1α, IL-1β, IL-6, IL-8, TNFα, CCL2) were increased both within explants and in conditioned culture medium. Hypoxia increased tissue IL-1α/β, IL-6, IL-8 and TNFα levels, and release of IL-1α, IL-6 and IL-8, whereas CCL2 and IL-10 were reduced. IL1 receptor antagonist (IL1Ra) treatment prevented hypoxia- and oxidative stress-induced IL-6 and IL-8 release. These findings provide evidence that relevant stressors induce a sterile inflammatory profile in placental tissue which can be partially blocked by IL1Ra suggesting this agent has translational potential to prevent placental inflammation evident in FGR and stillbirth.

Impact of maternal immune activation on dendritic spine development

Dendritic spines are small dendritic protrusions that harbor most excitatory synapses in the brain. The proper generation and maturation of dendritic spines are crucial for the regulation of synaptic transmission and formation of neuronal circuits. Abnormalities in dendritic spine density and morphology are common pathologies in autism and schizophrenia. According to epidemiological studies, one risk factor for these neurodevelopmental disorders is maternal infection during pregnancy. This review discusses spine alterations in animal models of maternal immune activation in the context of neurodevelopmental disorders. We describe potential mechanisms that might be responsible for prenatal infection-induced changes in the dendritic spine phenotype and behavior in offspring.

Inflammation Biomarkers in Psychiatry

Introduction:

There has long been a need for diagnostic, theragnostic, and prognostic biomarkers for psychiatric disorders. Biomarkers help in reducing ambiguity and arbitrariness and increase objectivity. In this context, many candidates for hormonal, immunological, serological, and neuroimaging markers have been proposed, but none of these marker candidates alone nor a biomarker panel has been approved for any disease. The fact that almost all psychiatric disorders are heterogeneous makes this process challenging. However, strong biomarker candidates have been identified, especially in light of the large number of clinical and preclinical studies conducted within the last five years.

Objective:

The aim of this article was to compile and discuss the current information on immune biomarkers in major psychiatric disorders, such as schizophrenia, depression, bipolar disorder, and anxiety disorders.

Methods:

In this study, respected scientific databases were searched using key terms related to the subject, and the related literature was examined in detail.

Results:

There are many relationships between psychiatric disorders and immune system parameters. Evidence also suggests that neuroinflammation is involved in the etiopathogenesis of psychiatric disorders. Markers, such as proinflammatory cytokines, tumor necrosis factor alpha, and C-reactive protein have been associated with psychiatric disorders in numerous studies.

Conclusions:

The neuroinflammation hypothesis has an important place in the etiopathogenesis of psychiatric disorders. Uncertainty remains as to whether neuroinflammation is a cause or consequence of psychiatric disorders. Some researchers have indicated that intestinal microbiota composition disorders and dysbiosis are sources of neuroinflammation. Immune marker studies are of great importance in terms of eliminating this uncertainty and overcoming diagnostic and treatment difficulties in the clinic. In this review, biomarker studies on psychiatric disorders were examined from the viewpoint of the immune system and discussed in light of the current studies.

Critical Role of the Maternal Immune System in the Pathogenesis of Autism Spectrum Disorder

Autism spectrum disorders (ASD) are a group of neurodevelopmental disorders characterised by impairments in communication, social interaction, and the presence of restrictive and repetitive behaviours. Over the past decade, most of the research in ASD has focused on the contribution of genetics, with the identification of a variety of different genes and mutations. However, the vast heterogeneity in clinical presentations associated with this disorder suggests that environmental factors may be involved, acting as a “second hit” in already genetically susceptible individuals. To this regard, emerging evidence points towards a role for maternal immune system dysfunctions. This literature review considered evidence from epidemiological studies and aimed to discuss the pathological relevance of the maternal immune system in ASD by looking at the proposed mechanisms by which it alters the prenatal environment. In particular, this review focuses on the effects of maternal immune activation (MIA) by looking at foetal brain-reactive antibodies, cytokines and the microbiome. Despite the arguments presented here that strongly implicate MIA in the pathophysiology of ASD, further research is needed to fully understand the precise mechanisms by which they alter brain structure and behaviour. Overall, this review has not only shown the importance of the maternal immune system as a risk factor for ASD, but more importantly, has highlighted new promising pathways to target for the discovery of novel therapeutic interventions for the treatment of such a life-changing disorder.

Maternal inflammation leads to different mTORC1 activity varied by anatomic locations in mouse placenta†

Maternal inflammation (MI) is associated with many adverse perinatal outcomes. The placenta plays a vital role in mediating maternal-fetal resource allocation. Studies have shown that MI contributes to placental dysfunction, which then leads to adverse birth outcomes and high health risks throughout childhood. Placental mammalian target of rapamycin complex 1 (mTORC1) signaling pathway links maternal nutrient availability to fetal growth; however, the impact of MI on mTORC1 signaling in the placenta remains unclear. In this study, we sought to explore the changes of mTORC1 signaling in the mouse placenta at late gestation by using two models of MI employing lipopolysaccharide (LPS) and interleukin-1β (IL-1β) to mimic acute (aMI) and sub-chronic (cMI) inflammatory states, respectively. We determined placental mTORC1 activity by measuring the activity of mTORC1 downstream molecules, including S6k, 4Ebp1, and rpS6. In the aMI model, we found that mTORC1 activity was significantly decreased in the placental decidual and junctional zone at 2 and 6 h after LPS surgery, respectively; however, mTORC1 activity was significantly increased in the placental labyrinth zone at 2, 6, and 24 h after LPS treatment, respectively. In the cMI model, we observed that mTORC1 activity was increased only in the placental labyrinth zone after consecutive IL-1β exposure. Our study reveals that different parts of the mouse placenta react differently to MI, leading to variable mTORC1 activity throughout the placenta. This suggests that different downstream molecules of mTORC1 from different parts of the mouse placenta may be used in clinical research to monitor the fetal well-being during MI.

NLRP3 inflammasome function and pyroptotic cell death in human placental Hofbauer cells

Alterations in the number and protein/gene expression of Hofbauer cells (HBCs) may play a role in microbial-driven/cytokine-mediated placental inflammation, and in subsequent pregnancy complications such as villitis, histologic chorioamnionitis, and the fetal inflammatory response syndrome. Pyroptosis is an inflammatory form of cell death mediated by the inflammasome, a multi-protein complex which drives the processing and secretion of interleukin 1 beta (IL-1β). Pyroptosis can be triggered by bacterial lipopolysaccharide (LPS) and adenosine triphosphate (ATP) in non-placental macrophages through activation of the NLRP3 inflammasome. However, the role of inflammasome activation and pyroptosis in HBC pathophysiology remains unclear. HBCs isolated from human term placentas were treated with or without LPS or ATP, alone or in combination. Treatment of HBCs with both LPS and ATP induced the rapid secretion of high levels of IL-1β and at the same time, cell death associated with nuclear condensation and cellular swelling. HBC treatment with both LPS and ATP induced caspase-1 activation, gasdermin D (GSDMD) cleavage, which mediates pyroptosis, and IL-1β processing. Caspase-1 activation, GSDMD cleavage, IL-1β processing, and IL-1β secretion were all significantly reduced following NLRP3 knockdown; inhibition of caspase-1; and inhibition of P2X7, the receptor that mediates K⁺ efflux. Together, our data indicate that LPS and ATP treatment stimulated NLRP3 inflammasome activation and pyroptosis in HBCs leading to the rapid release of IL-1β. Since the localization of HBCs confers a unique ability to influence microbial-associated placental and fetal inflammation, these studies suggest a key role for the inflammasome and pyroptosis in mediating HBC driven inflammation.

In utero inflammatory challenge induces an early activation of the hepatic innate immune response in late gestation fetal sheep

Chorioamnionitis is associated with inflammatory end-organ damage in the fetus. Tissues in direct contact with amniotic fluid drive a pro-inflammatory response and contribute to this injury. However, due to a lack of direct contact with the amniotic fluid, the liver contribution to this response has not been fully characterized. Given its role as an immunologic organ, we hypothesized that the fetal liver would demonstrate an early innate immune response to an in utero inflammatory challenge. Fetal sheep (131 ± 1 d gestation) demonstrated metabolic acidosis and high cortisol and norepinephrine values within 5 h of exposure to intra-amniotic LPS. Likewise, expression of pro-inflammatory cytokines increased significantly at 1 and 5 h of exposure. This was associated with NF-κB activation, by inhibitory protein IκBα degradation, and nuclear translocation of NF-κB subunits (p65/p50). Corroborating these findings, LPS exposure significantly increased pro-inflammatory innate immune gene expression in fetal sheep hepatic macrophages in vitro. Thus, an in utero inflammatory challenge induces an early hepatic innate immune response with systemic metabolic and stress responses. Within the fetal liver, hepatic macrophages respond robustly to LPS exposure. Our results demonstrate that the fetal hepatic innate immune response must be considered when developing therapeutic approaches to attenuate end-organ injury associated with in utero inflammation.

Aminophylline and progesterone prevent inflammation-induced preterm parturition in the mouse†

Although progesterone (P4) supplementation is the most widely used therapy for the prevention of preterm labor (PTL), reports of its clinical efficacy have been conflicting. We have previously shown that the anti-inflammatory effects of P4 can be enhanced by increasing intracellular cyclic adenosine monophosphate (cAMP) levels in primary human myometrial cells. Here, we have examined whether adding aminophylline (Am), a non-specific phosphodiesterase inhibitor that increases intracellular cAMP levels, to P4 might improve its efficacy using in vivo and in vitro models of PTL. In a mouse model of lipopolysaccharide (LPS)-induced PTL, we found that the combination of P4 and Am delayed the onset of LPS-induced PTL, while the same dose of P4 and Am alone had no effect. Pup survival was not improved by either agent alone or in combination. Myometrial prolabor and inflammatory cytokine gene expression was reduced, but the reduction was similar in P4 and P4/Am treated mice. There was no effect of the combination of P4 and Am on an ex vivo assessment of myometrial contractility. In human myometrial cells and myometrial tissue explants, we found that the combination had marked anti-inflammatory effects, reducing cytokine and COX-2 mRNA and protein levels to a greater extent than either agent alone. These data suggest that the combination of P4 and Am has a more potent anti-inflammatory effect than either agent alone and may be an effective combination in women at high-risk of PTL.

Perinatal inflammation is associated with social and motor impairments in preterm children without severe neonatal brain injury

OBJECTIVE

To test the association between exposure to perinatal inflammation - i.e. clinical chorioamnionitis or early-onset neonatal infection - in preterm children without severe neonatal brain injury and neurodevelopmental outcome at 30 months of corrected age (CA).

DESIGN

Cross-sectional study from a French regional cohort of clinical follow-up (SEVE Network).

PATIENTS

One hundred sixty-four surviving neonates without severe brain injury - namely, grade III and IV cerebral hemorrhage and cystic periventricular leukomalacia - and without late-onset neonatal inflammation exposure - namely, late-onset neonatal infection and necrotizing enterocolitis -, born at less than 33 weeks of gestational age from November 2011 to June 2015 and enrolled in the SEVE Network.

MAIN OUTCOME MEASURE

Global developmental quotient (DQ) score of the revised Brunet-Lézine scale and its four indices measured by the same neuropsychologist at 30 months of CA.

RESULTS

After multivariate analysis, exposure to perinatal inflammation was not found significantly associated with a modification of the global DQ score (coefficient -1.7, 95% CI -4.8 to 1.3; p = 0.26). Exposure to perinatal inflammation was associated with a decrease of the gross motor function DQ score (coefficient -6.0, 95% CI -9.9 to -2.1; p < 0.01) and a decrease of the sociability DQ score (coefficient -5.1, 95% CI -9.2 to -0.9; p = 0.02). Language and visuospatial coordination DQ scores were not affected by exposure to perinatal inflammation.

CONCLUSION

Exposure to perinatal inflammation in preterm children without severe neonatal brain injury is independently associated with decreased motor and social abilities at 30 months of CA.

The prenatal challenge with lipopolysaccharide and polyinosinic:polycytidylic acid disrupts CX3CL1-CX3CR1 and CD200-CD200R signalling in the brains of male rat offspring: a link to schizophrenia-like behaviours

BACKGROUND

The bidirectional communication between neurons and microglia is fundamental for the homeostasis and biological function of the central nervous system. Maternal immune activation (MIA) is considered to be one of the factors affecting these interactions. Accordingly, MIA has been suggested to be involved in several neuropsychiatric diseases, including schizophrenia. The crucial regulatory systems for neuron-microglia crosstalk are the CX3CL1-CX3CR1 and CD200-CD200R axes.

METHODS

We aimed to clarify the impact of MIA on CX3CL1-CX3CR1 and CD200-CD200R signalling pathways in the brains of male Wistar rats in early and adult life by employing two neurodevelopmental models of schizophrenia based on the prenatal challenge with lipopolysaccharide (LPS) and polyinosinic:polycytidylic acid (Poly I:C). We also examined the effect of MIA on the expression of microglial markers and the profile of cytokines released in the brains of young offspring, as well as the behaviour of adult animals. Moreover, we visualized the localization of ligand-receptor systems in the hippocampal regions (CA1, CA3 and DG) and the frontal cortex of young rats exposed to MIA. The differences between groups were analysed using Student's t test.

RESULTS

We observed that MIA altered developmental trajectories in neuron-microglia communication in the brains of young offspring, as evidenced by the disruption of CX3CL1-CX3CR1 and/or CD200-CD200R axes. Our data demonstrated the presence of abnormalities after LPS-induced MIA in levels of Cd40, Il-1β, Tnf-α, Arg1, Tgf-β and Il-10, as well as IBA1, IL-1β and IL-4, while after Poly I:C-generated MIA in levels of Cd40, iNos, Il-6, Tgf-β, Il-10, and IBA1, IL-1β, TNF-α, IL-6, TGF-β and IL-4 early in the life of male animals. In adult male rats that experienced prenatal exposure to MIA, we observed behavioural changes resembling a schizophrenia-like phenotype.

CONCLUSIONS

Our study provides evidence that altered CX3CL1-CX3CR1 and/or CD200-CD200R pathways, emerging after prenatal immune challenge with LPS and Poly I:C, might be involved in the aetiology of schizophrenia.

The Role of Immune Factors in Shaping Fetal Neurodevelopment

Fetal neurodevelopment in utero is profoundly shaped by both systemic maternal immunity and local processes at the maternal-fetal interface. Immune pathways are a critical participant in the normal physiology of pregnancy and perturbations of maternal immunity due to infections during this period have been increasingly linked to a diverse array of poor neurological outcomes, including diseases that manifest much later in postnatal life. While experimental models of maternal immune activation (MIA) have provided groundbreaking characterizations of the maternal pathways underlying pathogenesis, less commonly examined are the immune factors that serve pathogen-independent developmental functions in the embryo and fetus. In this review, we explore what is known about the in vivo role of immune factors in fetal neurodevelopment during normal pregnancy and provide an overview of how MIA perturbs the proper orchestration of this sequence of events. Finally, we discuss how the dysregulation of immune factors may contribute to the manifestation of a variety of neurological disorders.

[Clinical and laboratory parallels at pathological and borderline states associated with lipopolysaccharides.]

The review systematizes data on the structure of lipopolysaccharides (LPS) and their role in physiological and systemic pathological processes. The analysis of literature and our own data is of scientific and practical interest for specialists in the field of clinical laboratory diagnostics, anesthesiologists, resuscitators, therapists, immunologists and obstetrician-gynecologists, including studies on the role of LPS in unique three-component systems - «mother-placenta-fetus». The prospects of using LPS as immunomodulatory, including for the treatment of infectious diseases, are justified. It is shown that along with their use for the correction of immunodeficiency or the development of new adjuvants and vaccines, it is possible to use their high regulatory activity even at the epigenetic level. The possibility of the prophylactic and therapeutic use of LPS in the context of an alternative solution to the problem of antibiotic resistance of bacteria is discussed.

Dose-dependent structural and immunological changes in the placenta and fetal brain in response to systemic inflammation during pregnancy

PROBLEM

Systemic maternal inflammation is associated with adverse neonatal sequelae. We tested the hypothesis that IL-1β is a key inflammatory regulator of adverse pregnancy outcomes.

METHOD OF STUDY

Pregnant mice were treated with intraperitoneal injections of IL-1β (0, 0.1, 0.5, or 1 μg) from embryonic day (E)14 to E17. Placenta and fetal brains were harvested and analyzed for morphologic changes and IL-1β signaling markers.

RESULTS

As compared with non-treated dams, maternal injections with IL-1β resulted in increased p-NF-κB and caspase-1 in placentas and fetal brains, but not consistently in spleens, suggesting induction of intrinsic IL-1β production. These findings were confirmed by increased levels of IL-1β in the placentas of the IL-1β-treated dams. Systemic treatment of dams with IL-1β suppressed Stat1 signaling. Maternal inflammation caused by IL-1β treatment reduced fetal viability to 80.6% and 58.9%, in dams treated with either 0.5 or 1 μg of IL-1β, respectively. In the placentas, there was an IL-1β dose-dependent distortion of the labyrinth structure, decreased numbers of mononuclear trophoblast giant cells, and reduced proportions of endothelial cells as compared to placentas from control dams. In fetal brains collected at E17, there was an IL-1β dose-dependent reduction in cortical neuronal morphology.

CONCLUSION

This work demonstrates that systemic IL-1β injection causes dose-dependent structural and functional changes in the placenta and fetal brain.