Immune synaptopathies: how maternal immune activation impacts synaptic function during development.

In the last two decades, the term synaptopathy has been largely used to underline the concept that impairments of synaptic structure and function are the major determinant of brain disorders, including neurodevelopmental disorders. This notion emerged from the progress made in understanding the genetic architecture of neurodevelopmental disorders, which highlighted the convergence of genetic risk factors onto molecular pathways specifically localized at the synapse. However, the multifactorial origin of these disorders also indicated the key contribution of environmental factors. It is well recognized that inflammation is a risk factor for neurodevelopmental disorders, and several immune molecules critically contribute to synaptic dysfunction. In the present review, we highlight this concept, which we define by the term "immune-synaptopathy," and we discuss recent evidence suggesting a bi-directional link between the genetic architecture of individuals and maternal activation of the immune system in modulating brain developmental trajectories in health and disease.

Prenatal inflammation exposure accelerates lung cancer tumorigenesis in offspring mouse: possible links to IRE1α/XBP1-mediated M2-like polarization of TAMs and PD-L1 up-expression.

BACKGROUND: Prenatal inflammation exposure (PIE) can increase the disease susceptibility in offspring such as lung cancer. Our purpose was to investigate the mechanisms of PIE on lung cancer. METHODS: Prenatal BALB/c mice were exposed to lipopolysaccharide (LPS), and then, their offspring were intraperitoneally instilled with urethane to establish the two-stage lung cancer carcinogenesis model. At the 48 weeks of age, the offspring mice were killed and lung tissues were collected for HE, immunohistochemistry, immunofluorescence, and Luminex MAGPIX®-based assays. CD11b + F4/80 + tumor-associated macrophages (TAMs) were sorted out from lung tumor tissues by cell sorting technique. Flow cytometry was employed to evaluate the extent of M2-like polarization of TAMs and PD-L1 expression. RESULTS: The offspring of PIE mice revealed more lung lesion changes, including atypical hyperplasia and intrapulmonary metastases. The number of lung nodules, lung organ index, and PCNA, MMP-9 and Vimentin positive cells in lung tissue of PIE group were higher than those of Control group. The increases of mRNA encoding M2 macrophage markers and cytokines in offspring of prenatal LPS-treated mice confirmed the induced effect of PIE on macrophage polarization. Additionally, PIE treatment increased the percentage of CD163 + CD206 + cells in the sorted TAMs. Importantly, endoplasmic reticulum (ER) stress-markers like GRP78/BIP and CHOP, p-IRE1α and XBP1s, and PD-L1 were up-regulated in TAMs from PIE group. Besides, we also observed that IRE1α inhibitor (KIRA6) reversed the M2-like TAMs polarization and metastasis induced by PIE. CONCLUSIONS: IRE1α/XBP1-mediated M2-like TAMs polarization releases the pro-tumorigenic cytokines and PD-L1 expression, which may be the regulatory mechanism of accelerating lung cancer in offspring of mice undergoing PIE.

Overactivated Epithelial NF-κB Disrupts Lung Development in Congenital Diaphragmatic Hernia.

Abnormal lung development is the main cause of morbidity and mortality in neonates with congenital diaphragmatic hernia (CDH), a common birth defect (1:2,500) of largely unknown pathobiology. Recent studies discovered that inflammatory processes, and specifically NF-κB-associated pathways, are enriched in human and experimental CDH. However, the molecular signaling of NF-κB in abnormal CDH lung development and its potential as a therapeutic target require further investigation. Using sections and hypoplastic lung explant cultures from the nitrofen rat model of CDH and human fetal CDH lungs, we demonstrate that NF-κB and its downstream transcriptional targets are hyperactive during abnormal lung formation in CDH. NF-κB activity was especially elevated in the airway epithelium of nitrofen and human CDH lungs at different developmental stages. Fetal rat lung explants had impaired pseudoglandular airway branching after exposure to nitrofen, together with increased phosphorylation and transcriptional activity of NF-κB. Dexamethasone, the broad and clinically applicable antiinflammatory NF-κB antagonist, rescued lung branching and normalized NF-κB signaling in hypoplastic lung explants. Moreover, specific NF-κB inhibition with curcumenol similarly rescued ex vivo lung hypoplasia and restored NF-κB signaling. Last, we showed that prenatal intraperitoneal dexamethasone administration to pregnant rat dams carrying fetuses with hypoplastic lungs significantly improves lung branching and normalizes NF-κB in vivo. Our results indicate that NF-κB is aberrantly activated in human and nitrofen CDH lungs. Antiinflammatory treatment with dexamethasone and/or specific NF-κB inhibition should be investigated further as a therapeutic avenue to target lung hypoplasia in CDH.

Disruptions in Hypothalamic-Pituitary-Gonadal Axis Development and Their IgG Modulation after Prenatal Systemic Inflammation in Male Rats.

The development of the neuroendocrine system, including the hypothalamic-pituitary-gonadal (HPG) axis, is sensitive to environmental impacts during critical developmental periods. Maternal immune system activation by bacterial or viral infection may be one of the negative impacts. This study focused on the effect of systemic inflammation induced by lipopolysaccharides (LPS E. coli) on the HPG axis development in male rat offspring, corrected by the anti-inflammatory action of polyclonal IgG and monoclonal anti-interleukin (IL)-6 receptor antibodies (IL-6RmAbs). A single LPS exposure on the 12th embryonic day (ED) led to a decrease in the number of afferent synaptic inputs on gonadotropin-releasing, hormone-producing neurons in adult male offspring. LPS exposure on ED18 did not lead to such disruptions. Moreover, after the LPS injections on ED12, circulating follicle-stimulating hormone and sex steroid levels were reduced, and the gonadal structure was disrupted. A prenatal IL-6R blockade with IL-6RmAbs and polyclonal IgG reduced the negative effects of inflammation on fetal HPG axis development. Overall, the data obtained confirm the morphogenetic effect of inflammation on fetal HPG development and IL-6 involvement in these processes.

Prenatal inflammation exposure-programmed hypertension exhibits multi-generational inheritance via disrupting DNA methylome.

The multi-generation heredity trait of hypertension in human has been reported, but the molecular mechanisms underlying multi-generational inheritance of hypertension remain obscure. Recent evidence shows that prenatal inflammatory exposure (PIE) results in increased incidence of cardiovascular diseases, including hypertension. In this study we investigated whether and how PIE contributed to multi-generational inheritance of hypertension in rats. PIE was induced in pregnant rats by intraperitoneal injection of LPS or Poly (I:C) either once on gestational day 10.5 (transient stimulation, T) or three times on gestational day 8.5, 10.5, and 12.5 (persistent stimulation, P). Male offspring was chosen to study the paternal inheritance. We showed that PIE, irrespectively induced by LPS or Poly (I:C) stimulation during pregnancy, resulted in multi-generational inheritance of significantly increased blood pressure in rat descendants, and that prenatal LPS exposure led to vascular remodeling and vasoconstrictor dysfunction in both thoracic aorta and superior mesenteric artery of adult F2 offspring. Furthermore, we revealed that PIE resulted in global alteration of DNA methylome in thoracic aorta of F2 offspring. Specifically, PIE led to the DNA hypomethylation of G beta gamma (Gßγ) signaling genes in both the F1 sperm and the F2 thoracic aorta, and activation of PI3K/Akt signaling was implicated in the pathologic changes and dysregulated vascular tone of aortic tissue in F2 LPS-P offspring. Our data demonstrate that PIE reprogrammed DNA methylome of cells from the germline/mature gametes contributes to the development of hypertension in F2 PIE offspring. This study broadens the current knowledge regarding the multi-generation effect of the cumulative early life environmental factors on the development of hypertension.

Maternal viral infection causes global alterations in porcine fetal microglia.

Maternal infections during pregnancy are associated with increased risk of neurodevelopmental disorders, although the precise mechanisms remain to be elucidated. Previously, we established a maternal immune activation (MIA) model using swine, which results in altered social behaviors of piglet offspring. These behavioral abnormalities occurred in the absence of microglia priming. Thus, we examined fetal microglial activity during prenatal development in response to maternal infection with live porcine reproductive and respiratory syndrome virus. Fetuses were obtained by cesarean sections performed 7 and 21 d postinoculation (dpi). MIA fetuses had reduced brain weights at 21 dpi compared to controls. Furthermore, MIA microglia increased expression of major histocompatibility complex class II that was coupled with reduced phagocytic and chemotactic activity compared to controls. High-throughput gene-expression analysis of microglial-enriched genes involved in neurodevelopment, the microglia sensome, and inflammation revealed differential regulation in primary microglia and in whole amygdala tissue. Microglia density was increased in the fetal amygdala at 7 dpi. Our data also reveal widespread sexual dimorphisms in microglial gene expression and demonstrate that the consequences of MIA are sex dependent. Overall, these results indicate that fetal microglia are significantly altered by maternal viral infection, presenting a potential mechanism through which MIA impacts prenatal brain development and function.

Maternal serum C-reactive protein (CRP) and offspring attention deficit hyperactivity disorder (ADHD).

Exposure to infection and inflammation during the fetal period are associated with offspring neuropsychiatric disorders. Few previous studies have examined this association with ADHD with mixed findings. This study aims to examine the association between early gestational maternal C-reactive protein (CRP), prospectively assayed in stored maternal sera and the risk of ADHD in offspring. This study is based on the Finnish Prenatal studies of ADHD (FIPS-ADHD) with a nested case-control design. It includes all singleton-born children in Finland between January 1, 1998 and December 31, 1999 and diagnosed with ADHD. A total of 1079 cases and equal number of controls were matched on date of birth, sex and place of birth. Maternal CRP levels were assessed using a latex immunoassay from archived maternal serum specimens, collected during the first and early second trimester of pregnancy. Elevated maternal CRP when analyzed as a continuous variable was not associated with offspring ADHD (OR 1.05, 95% CI 0.96-1.15). No significant associations were seen in the highest quintile of CRP (OR 1.18, 95% CI 0.88-1.58). The results were similar in both sexes as well as among ADHD cases with or without comorbid ASD or conduct disorder. In this first study examining CRP, a biomarker for inflammation, during early pregnancy in relation to offspring ADHD, we report no significant associations. The lack of any association, when considered with positive findings seen in ASD and schizophrenia, and negative findings in bipolar disorder suggests different pathways linking maternal immune activation and development of various neuropsychiatric disorders.

Gut and immune effects of bioactive milk factors in preterm pigs exposed to prenatal inflammation.

Prenatal inflammation may predispose to preterm birth and postnatal inflammatory disorders such as necrotizing enterocolitis (NEC). Bioactive milk ingredients may help to support gut maturation in such neonates, but mother's milk is often insufficient after preterm birth. We hypothesized that supplementation with bioactive ingredients from bovine milk [osteopontin (OPN), caseinoglycomacropeptide (CGMP), colostrum (COL)] supports gut, immunity, and NEC resistance in neonates born preterm after gram-negative infection before birth. Using preterm pigs as a model for preterm infants, fetal pigs were given intraamniotic injections of lipopolysaccharide (LPS; 1 mg/fetus) and delivered 3 days later (90% gestation). For 5 days, groups of LPS-exposed pigs were fed formula (FOR), bovine colostrum (COL), or formula enriched with OPN or CGMP. LPS induced intraamniotic inflammation and postnatal systemic inflammation but limited effects on postnatal gut parameters and NEC. Relative to FOR, COL feeding to LPS-exposed pigs showed less diarrhea, NEC severity, reduced gut IL-1ß and IL-8 levels, greater gut goblet cell density and digestive enzyme activities, and blood helper T-cell fraction. CGMP improved neonatal arousal and gut lactase activities and reduced LPS-induced IL-8 secretion in intestinal epithelial cells (IECs) in vitro. Finally, OPN tended to reduce diarrhea and stimulated IEC proliferation in vitro. No effects on villus morphology, circulating cytokines, or colonic microbiota were observed among groups. In conclusion, bioactive milk ingredients exerted only modest effects on gut and systemic immune parameters in preterm pigs exposed to prenatal inflammation. Short-term, prenatal exposure to inflammation may render the gut less sensitive to immune-modulatory milk effects. NEW & NOTEWORTHY Prenatal inflammation is a risk factor for preterm birth and postnatal complications including infections. However, from clinical studies, it is difficult to separate the effects of only prenatal inflammation from preterm birth. Using cesarean-delivered preterm pigs with prenatal inflammation, we documented some beneficial gut effects of bioactive milk diets relative to formula, but prenatal inflammation appeared to decrease the sensitivity of enteral feeding. Special treatments and diets may be required for this neonatal population.

Disruptions in the reproductive system of female rats after prenatal lipopolysaccharide-induced immunological stress: role of sex steroids.

Stress signals during fetal or early postnatal periods may disorganize reproductive axis development at different levels. This study was aimed to test the hypothesis that prenatal immunological stress induced by bacterial endotoxin, lipopolysaccharide (LPS), has impact on structure and function of the reproductive system in female offspring. Adult female Wistar rats were divided into two groups, a control group (n = 5) and a LPS group (n = 12). Rats were injected with LPS 50 µg/kg body or 0.9% saline intraperitoneally on the 12th day of pregnancy. After birth the female pups (n = 20 in each group) were divided into four groups: (group 1) 0.9% saline prenatally, sesame oil (vehicle) postnatally; (group 2) LPS prenatally, sesame oil postnatally; (group 3) LPS prenatally, fulvestrant postnatally; (group 4) LPS prenatally, flutamide postnatally. Pups were injected subcutaneously into the neck with fulvestrant (estrogen receptor antagonist), 1.5 mg/kg in sesame oil, from postnatal day (PND) 5 to PND14; or flutamide (androgen receptor antagonist), 20 mg/kg in sesame oil, from PND14 to PND30. Rats of the control group were injected with sesame oil during the same time period. Parameters were evaluated by ELISA (serum estradiol and testosterone) and ovarian histology. The main findings were: (1) prenatal stress during the critical period resulted in delayed vaginal opening, decreased body weight and serum concentrations of sex steroids, and significant disorders in ovarian development; (2) postnatal estradiol and testosterone antagonist treatments decreased follicular atresia through increasing the number of healthy follicles and restored endogenous steroid production. Lay summaryImmunological stress, caused by simulating infection through exposure to a bacterial toxin (LPS), during a critical period of fetal development in laboratory rats results in delayed reproductive maturity, decreased body weight and decreased secretion of sex steroids in female offspring, and abnormalities in the ovaries like those in polycystic ovarian syndrome. These prenatally toxin-induced sexual disorders in females could be corrected by estradiol/testosterone antagonists during the postnatal period.

Abolition of prenatal lipopolysaccharide-induced reproductive disorders in rat male offspring by fulvestrant.

During prenatal and early postnatal periods of development, multiple environmental factors have profound and long-lasting effects on the immune and reproductive functions. The aim of this study was to investigate the effects of maternal lipopolysaccharide (LPS) exposure (50 mg/kg, i.p.) at day 12 of pregnancy and estradiol antagonist treatment (fulvestrant, 1.5 mg/kg, s.c. in neck) at postnatal days 5-14 (PND5-14) with high estradiol levels on reproductive parameters in adult rat males. Serum steroid concentrations were measured in male offspring at PND80 by ELISA. Body, testis weights and ano-genital distance (AGD) were recorded at different stages of postnatal development. Testis was also processed to cytohistological studies at PND80. Our results demonstrate that body weight was decreased from PND14 to 30 after prenatal LPS treatment and was increased after fulvestrant treatment. AGD was decreased after prenatal LPS treatment and was increased after fulvestrant injections. Testis weight, testosterone level, seminiferous tubule diameter, and number of Sertoli and spermatid cells were also decreased in rats exposed prenatally to LPS and were restored to the normal control level after fulvestrant treatment. According to results, we can conclude that the development of sexual disorders in males after prenatal immune stress is potentiated by estradiol during the pre-pubertal period.

Intrauterine inflammation induces sex-specific effects on neuroinflammation, white matter, and behavior.

Exposure to inflammation during pregnancy has been linked to adverse neurodevelopmental consequences for the offspring. One common route through which a developing fetus is exposed to inflammation is with intrauterine inflammation. To that end, we utilized an animal model of intrauterine inflammation (IUI; intrauterine lipopolysaccharide (LPS) administration, 50µg, E15) to assess placental and fetal brain inflammatory responses, white matter integrity, anxiety-related behaviors (elevated zero maze, light dark box, open field), microglial counts, and the CNS cytokine response to an acute injection of LPS in both males and females. These studies revealed that for multiple endpoints (fetal brain cytokine levels, cytokine response to adult LPS challenge) male IUI offspring were uniquely affected by intrauterine inflammation, while for other endpoints (behavior, microglial number) both sexes were similarly affected. These data advance our understanding of sex-specific effects of early life exposure to inflammation in a translationally- relevant model.

Disruptions in the hypothalamic-pituitary-gonadal axis in rat offspring following prenatal maternal exposure to lipopolysaccharide.

Postnatal treatment with bacterial endotoxin lipopolysaccharide (LPS) changes the activity of the hypothalamic-pituitary-gonadal (HPG) axis and the gonadotropin-releasing hormone (GnRH) surge in rats. Exposure to an immune challenge in the critical periods of development has profound and long-lasting effects on the stress response, immune, metabolic, and reproductive functions. Prenatal LPS treatment delays the migration of GnRH neurons associated with increased cytokine release in maternal and fetal compartments. We investigated the effects of a single maternal exposure to LPS (18 µg/kg, i.p.) on day 12 (embryonic day (E)12) of pregnancy on reproductive parameters in rat offspring. Hypothalamic GnRH content, plasma luteinizing hormone (LH), testosterone, and estradiol concentrations were measured in both male and female offsprings at different stages of postnatal development by RIA and ELISA (n = 10 each per group). Body weight and in females day of vaginal opening (VO) were recorded. In offspring exposed to LPS prenatally, compared with controls, body weight was decreased in both sexes at P5 and P30; in females, VO was delayed; hypothalamic GnRH content was decreased at postnatal days 30-60 (P30-P60) in both sexes; plasma LH concentration was decreased at P14-P60 in females; plasma concentrations of testosterone/estradiol were increased at P14 in females, and plasma estradiol was increased at P14 in males. Hence activation of the maternal immune system by LPS treatment at a prenatal critical period leads to decreased GnRH and LH levels in pre- and postpubertal life and sex steroid imbalance in the prepubertal period, and delayed sexual maturation of female offspring.

Microglia shape corpus callosum axon tract fasciculation: functional impact of prenatal inflammation.

Microglia colonise the brain parenchyma at early stages of development and accumulate in specific regions where they participate in cell death, angiogenesis, neurogenesis and synapse elimination. A recurring feature of embryonic microglial is their association with developing axon tracts, which, together with in vitro data, supports the idea of a physiological role for microglia in neurite development. Yet the demonstration of this role of microglia is lacking. Here, we have studied the consequences of microglial dysfunction on the formation of the corpus callosum, the largest commissure of the mammalian brain, which shows consistent microglial accumulation during development. We studied two models of microglial dysfunction: the loss-of-function of DAP12, a key microglial-specific signalling molecule, and a model of maternal inflammation by peritoneal injection of lipopolysaccharide at embryonic day (E)15.5. We also took advantage of the Pu.1(-/-) mouse line, which is devoid of microglia. We performed transcriptional profiling of maternally inflamed and Dap12-mutant microglia at E17.5. The two treatments principally down-regulated genes involved in nervous system development and function, particularly in neurite formation. We then analysed the developmental consequences of these microglial dysfunctions on the formation of the corpus callosum. We show that all three models of altered microglial activity resulted in the defasciculation of dorsal callosal axons. Our study demonstrates that microglia display a neurite-development-promoting function and are genuine actors of corpus callosum development. It further shows that microglial activation impinges on this function, thereby revealing that prenatal inflammation impairs neuronal development through a loss of trophic support.

Prenatal inflammation is associated with adverse neonatal outcomes.

OBJECTIVE: The purpose of this study was to determine whether prenatal inflammation (as assessed by clinical chorioamnionitis, maternal temperature >38°C, or histologic chorioamnionitis) is associated with a composite adverse neonatal outcome. STUDY DESIGN: We performed a prospective cohort study of women at 22 weeks to 33 weeks 6 days' gestation with symptoms of labor (April 2009 to March 2012). Relevant maternal and neonatal exposures and outcomes were recorded. Multivariable logistic regression was performed to determine the association between prenatal inflammation and neonatal outcomes that were controlled for potential confounders. RESULTS: We analyzed 871 mother-infant pairs. The preterm birth rate was 42.0%. When we controlled for infant sex and modified the data by gestational age at delivery, prenatal inflammation remains a significant risk factor for adverse neonatal outcomes, despite advancing gestational age: clinical chorioamnionitis at 32 weeks' gestation (odds ratio [OR], 3.12; 95% confidence interval [CI], 1.02-9.52], at 36 weeks' gestation (OR, 8.88; 95% CI, 4.32-18.25), and at 40 weeks' gestation (OR, 25.30; 95% CI, 9.25-69.19); maternal temperature >38°C at 32 weeks' gestation (OR, 3.18; 95% CI, 0.66-15.42), at 36 weeks gestation (OR, 8.40; 95% CI, 3.60-19.61), and at 40 weeks gestation (OR, 22.19; 95% CI, 8.15-60.44); histologic chorioamnionitis at 32 weeks gestation (OR, 1.25; 95% CI, 0.64-2.46), at 36 weeks gestation (OR, 2.56; 95% CI, 1.54-4.23), and at 40 weeks gestation (OR, 5.23; 95% CI, 1.95-13.99). CONCLUSION: The protective association with advancing gestational age is diminished when prenatal inflammation is present.

Multipotent adult progenitor cells prevent functional impairment and improve development in inflammation driven detriment of preterm ovine lungs.

Background: Perinatal inflammation increases the risk for bronchopulmonary dysplasia in preterm neonates, but the underlying pathophysiological mechanisms remain largely unknown. Given their anti-inflammatory and regenerative capacity, multipotent adult progenitor cells (MAPC) are a promising cell-based therapy to prevent and/or treat the negative pulmonary consequences of perinatal inflammation in the preterm neonate. Therefore, the pathophysiology underlying adverse preterm lung outcomes following perinatal inflammation and pulmonary benefits of MAPC treatment at the interface of prenatal inflammatory and postnatal ventilation exposures were elucidated. Methods: Instrumented ovine fetuses were exposed to intra-amniotic lipopolysaccharide (LPS 5 mg) at 125 days gestation to induce adverse systemic and peripheral organ outcomes. MAPC (10 × 106 cells) or saline were administered intravenously two days post LPS exposure. Fetuses were delivered preterm five days post MAPC treatment and either killed humanely immediately or mechanically ventilated for 72 h. Results: Antenatal LPS exposure resulted in inflammation and decreased alveolar maturation in the preterm lung. Additionally, LPS-exposed ventilated lambs showed continued pulmonary inflammation and cell junction loss accompanied by pulmonary edema, ultimately resulting in higher oxygen demand. MAPC therapy modulated lung inflammation, prevented loss of epithelial and endothelial barriers and improved lung maturation in utero. These MAPC-driven improvements remained evident postnatally, and prevented concomitant pulmonary edema and functional loss. Conclusion: In conclusion, prenatal inflammation sensitizes the underdeveloped preterm lung to subsequent postnatal inflammation, resulting in injury, disturbed development and functional impairment. MAPC therapy partially prevents these changes and is therefore a promising approach for preterm infants to prevent adverse pulmonary outcomes.

Prenatal inflammation remodels lung immunity and function by programming ILC2 hyperactivation.

Here, we examine how prenatal inflammation shapes tissue function and immunity in the lung by reprogramming tissue-resident immune cells from early development. Maternal, but not fetal, type I interferon-mediated inflammation provokes expansion and hyperactivation of group 2 innate lymphoid cells (ILC2s) seeding the developing lung. Hyperactivated ILC2s produce increased IL-5 and IL-13 and are associated with acute Th2 bias, decreased Tregs, and persistent lung eosinophilia into adulthood. ILC2 hyperactivation is recapitulated by adoptive transfer of fetal liver precursors following prenatal inflammation, indicative of developmental programming at the fetal progenitor level. Reprogrammed ILC2 hyperactivation and subsequent lung immune remodeling, including persistent eosinophilia, is concomitant with worsened histopathology and increased airway dysfunction equivalent to papain exposure, indicating increased asthma susceptibility in offspring. Our data elucidate a mechanism by which early-life inflammation results in increased asthma susceptibility in the presence of hyperactivated ILC2s that drive persistent changes to lung immunity during perinatal development.

Prenatal inflammation causes obesity and abnormal lipid metabolism via impaired energy expenditure in male offspring.

INTRODUCTION: Obesity has becoming a global health issue. Fetus exposed to adversity in the uterine are susceptible to unhealth stimulus in adulthood. Prenatal inflammation is related to poor neonatal outcomes like neurodevelopmental impairments and respiratory complications. Recent studies suggested prenatal lipopolysaccharide (LPS) exposure could result in metabolic disorders. Thus, we hypothesized that offspring exposed to prenatal inflammation could develop into metabolic disorder. METHODS: The pregnant C57BL/6J mice were intraperitoneally injected with 50 µg/kg LPS or saline only once at GD15. The male offspring were weighted weekly until sacrificed. Indirect calorimetry and body composition were both performed at 9 and 18 weeks old. At 20 weeks old, mice were fasted overnight before collecting blood samples and liver for metabolomics analysis and RNA sequencing, respectively. Differentially expressed genes were further verified by RT-qPCR and western blotting. RESULTS: Prenatal inflammation resulted in obesity with increased fat percentage and decreased energy expenditure in middle-age male offspring. Abnormal lipid accumulation, changes of gene expression profile and upregulation of multi-component mechanistic target of rapamycin complex 1 (mTOR)/Peroxisome proliferator-activated receptor-γ pathway was observed in liver, accompanied with decreased bile acids level, unsaturated fatty acids androgens and prostaglandins in serum. Indirect calorimetry showed increased respiratory exchange rate and deceased spontaneous activity at 9 weeks in LPS group. Impaired energy expenditure was also observed at 18 weeks in LPS group. CONCLUSION: Prenatal LPS exposure led to obesity and abnormal lipid metabolism through impaired energy expenditure.

Prenatal exposure to inflammation increases anxiety-like behaviors in F1 and F2 generations: possible links to decreased FABP7 in hippocampus.

Anxiety disorder has a high prevalence, and the risk of anxiety increases with age. Prenatal inflammation during key developmental timepoints can result in long-term changes in anxiety phenotype, even over a lifetime and across generations. However, whether maternal inflammation exposure during late gestation has intergenerational transmission effects on age-related anxiety-like behaviors and the possible underlying mechanisms are largely unknown. Fatty acid binding protein 7 (FABP7) is critical in hippocampal neurogenesis and is closely related to neuropsychiatric diseases, including anxiety disorder. The current study investigated the effects of maternal (F0 generation) lipopolysaccharide administration (50 µg/kg, i.p.) during late gestation on anxiety-like behaviors and FABP7 expression in F1 and F2 offspring, as well as the potential sex-specificity of intergenerational effects. Anxiety-like behaviors were evaluated using open field (OF), elevated plus maze, and black-white alley (BWA) tests at 3 and 13 months of age. The protein and messenger RNA levels of FABP7 in the hippocampus were measured using Western blot and real-time quantitative polymerase chain reaction (PCR), respectively. Overall, gestational LPS exposure in the F0 generation increased anxiety levels and decreased FABP7 expression levels in the F1 generation, which carried over to the F2 generation, and the intergenerational effects were mainly transferred via the maternal lineage. Moreover, hippocampal FABP7 expression was significantly correlated with performance in the battery of anxiety tests. The present study suggested that prenatal inflammation could increase age-related anxiety-like behaviors both in F1 and F2 offspring, and these effects possibly link to the FABP7 expression.

Direct Implementation of Intestinal Permeability Test in NMR Metabolomics for Simultaneous Biomarker Discovery-A Feasibility Study in a Preterm Piglet Model.

Measurement of intestinal permeability (IP) is often used in the examination of inflammatory gastrointestinal disorders. IP can be assessed by measurement of urinary recovery of ingested non-metabolizable lactulose (L) and mannitol (M). The present study aimed to examine how measurements of IP can be integrated in a NMR-based metabolomics approach for a simultaneous quantification of L/M ratio and biomarker exploration. For this purpose, plasma and urine samples were collected from five-day-old preterm piglets (n = 20) with gastrointestinal disorders (subjected to intra-amniotic lipopolysaccharide (LPS, 1 mg/fetus)) after they had been administrated a 5% lactulose and 5% mannitol solution (15 mL/kg). The collected plasma and urine samples were analyzed by 1H NMR-based metabolomics. Urine L/M ratio measured by 1H NMR spectroscopy showed high correlation with the standard measurement of the urinary recoveries by enzymatic assays (r = 0.93, p < 0.05). Partial least squares (PLS) regressions and correlation analyses between L/M ratio and NMR metabolomics data revealed that L/M ratio was positively correlated with plasma lactate, acetate and succinate levels and negatively correlated with urinary hippuric acid and glycine. In conclusion, the present study demonstrated that NMR metabolomics enables simultaneous IP testing and discovery of biomarkers associated with an impaired intestinal permeability.

Maternal Inflammation and Neurodevelopmental Programming: A Review of Preclinical Outcomes and Implications for Translational Psychiatry.

Early disruptions to neurodevelopment are highly relevant to understanding both psychiatric risk and underlying pathophysiology that can be targeted by new treatments. Much convergent evidence from the human literature associates inflammation during pregnancy with later neuropsychiatric disorders in offspring. Preclinical models of prenatal inflammation have been developed to examine the causal maternal physiological and offspring neural mechanisms underlying these findings. Here we review the strengths and limitations of preclinical models used for these purposes and describe selected studies that have shown maternal immune impacts on the brain and behavior of offspring. Maternal immune activation in mice, rats, nonhuman primates, and other mammalian model species have demonstrated convergent outcomes across methodologies. These outcomes include shifts and/or disruptions in the normal developmental trajectory of molecular and cellular processes in the offspring brain. Prenatal developmental origins are critical to a mechanistic understanding of maternal immune activation-induced alterations to microglia and immune molecules, brain growth and development, synaptic morphology and physiology, and anxiety- and depression-like, sensorimotor, and social behaviors. These phenotypes are relevant to brain functioning across domains and to anxiety and mood disorders, schizophrenia, and autism spectrum disorder, in which they have been identified. By turning a neurodevelopmental lens on this body of work, we emphasize the importance of acute changes to the prenatal offspring brain in fostering a better understanding of potential mechanisms for intervention. Collectively, overlapping results across maternal immune activation studies also highlight the need to examine preclinical offspring neurodevelopment alterations in terms of a multifactorial immune milieu, or immunome, to determine potential mechanisms of psychiatric risk.