Microplastics caused embryonic growth retardation and placental dysfunction in pregnant mice by activating GRP78/IRE1α/JNK axis induced apoptosis and endoplasmic reticulum stress.

Microplastics (MPs), a brand-new class of worldwide environmental pollutant, have received a lot of attention. MPs are consumed by both humans and animals through water, food chain and other ways, which may cause potential health risks. However, the effects of MPs on embryonic development, especially placental function, and its related mechanisms still need to be further studied. We investigated the impact on fetal development and placental physiological function of pregnant mice by consecutive gavages of MPs at 0, 25, 50, 100 mg/kg body weight during gestational days (GDs 0-14). The results showed that continuous exposure to high concentrations of MP significantly reduced daily weight gain and impaired reproductive performance of pregnant mice. In addition, MPs could significantly induce oxidative stress and placental dysfunction in pregnant mice. On the other hand, MPs exposure significantly decreased placental barrier function and induced placental inflammation. Specifically, MPs treatment significantly reduced the expression of tight junction proteins in placentas, accompanied by inflammatory cell infiltration and increased mRNA levels of pro-inflammatory cytokines and chemokines in placentas. Finally, we found that MPs induced placental apoptosis and endoplasmic reticulum (ER) stress through the GRP78/IRE1α/JNK axis, leading to placental dysfunction and decreased reproductive performance in pregnant mice. We revealed for the first time that the effects of MPs on placental dysfunction in pregnant animals. Blocking the targets of MPs mediated ER stress will provide potential therapeutic ideas for the toxic effects of MPs on maternal pregnancy.

Sex Differences in Impacts of Early Gestational and Peri-Adolescent Ozone Exposure on Lung Development in Rats: Implications for Later Life Disease in Humans.

Air pollution exposure during pregnancy may affect fetal growth. Fetal growth restriction (FGR) is associated with reduced lung function in children that can persist into adulthood. Using an established model of asymmetrical FGR in Long-Evans rats, this study investigated sex differences in effects of early life ozone exposure on lung development and maturation. Adverse health effects for i) gestational exposure (with impacts on primary alveolarization), ii) peri-adolescent exposure (with impacts on secondary alveolarization), and iii) cumulative exposure across both periods were evaluated. Notably, female offspring were most affected by gestational ozone exposure, likely because of impaired angiogenesis and corresponding decreases in primary alveolarization. Females had diminished lung capacity, fewer mature alveoli, and medial hypertrophy of small and large pulmonary arteries. Males, especially FGR-prone offspring, were more affected by peri-adolescent ozone exposure. Males had increased ductal areas, likely due to disrupted secondary alveolarization. Altered lung development may increase risk of developing diseases, such as pulmonary arterial hypertension or chronic obstructive pulmonary disease. Pulmonary arterial hypertension disproportionately affects women. In the United States, chronic obstructive pulmonary disease prevalence is increasing, especially in women; and prevalence for both men and women is highest in urbanized areas. This investigation underlines the importance of evaluating results separately by sex, and provides biologic plausibility for later consequences of early-life exposure to ozone, a ubiquitous urban air pollutant.

Maternal ozone exposure lowers infant's birthweight: A nationwide cohort of over 4 million livebirths in Iran.

BACKGROUND: Nationwide evidence linking maternal ozone exposure with fetal growth restriction (FGR) was extensively scarce, especially in the Middle East with dry climate and distinct religious culture. METHODS: We carried out a national retrospective birth cohort study using registry-based records from 749 hospitals across 31 provinces in Iran from 2013 to 2018. Monthly concentrations of maximum daily average 8-hour (MDA8) ozone at 0.125° × 0.125° resolution were extracted from well-validated spatiotemporal grid dataset. Linear and logistic regression models were employed to evaluate associations of maternal MDA8 ozone exposure with birthweight outcomes. Assuming causality, the comparative risk assessment framework was utilized to estimate the burden of low birthweight (LBW), small for gestational age (SGA), and birthweight loss per livebirth (BLL) attributable to ambient ozone pollution. RESULTS: Of 4030383 livebirths included in the study, 264304 (6.6%) were LBW and 484405 (12.0%) were SGA. Each 10-ppb increase in MDA8 ozone exposure was associated with an odds ratio of 1.123 (95% confidence interval [CI]: 1.104 to 1.142) for LBW and 1.210 (95% CI: 1.197 to 1.223) for SGA, and a 30.5-g (95% CI: 29.0 to 32.0) reduction in birthweight. We observed approximately linear exposure-response relationships of maternal MDA8 ozone exposure with LBW (Pnonlinear= 0.786), SGA (Pnonlinear= 0.156), and birthweight reduction (Pnonlinear= 0.104). Under the premise of causal association, we estimated 6.6% (95% CI: 5.7 to 7.5) of LBW, 10.1% (95% CI: 9.6 to 10.6) of SGA, and 18.8 g (95% CI: 17.9 to 19.7) of BLL could be attributable to maternal ozone exposure in Iran. Considerably greater risk and burden of ozone-related FGR were observed among younger, less-educated, and rural-dwelling mothers. CONCLUSIONS: Our study provided compelling evidence that maternal ozone exposure was associated with heightened FGR risk and burden, particularly among socioeconomically disadvantaged mothers. These findings underscored the urgent need for government to incorporate socioeconomic factors into future ozone-related health policies, not only to mitigate pollution, but also minimize inequality.

Different Lengths of Gestational Exposure to Secondhand Smoke or e-Cigarette Vapor Induce the Development of Placental Disease Symptoms.

Exposure to cigarette smoke is known to induce disease during pregnancy. Recent evidence showed that exposure to secondhand smoke (SHS) negatively impacts fetal and placental weights, leading to the development of intrauterine growth restriction (IUGR). Electronic cigarettes (eCigs) represent a phenomenon that has recently emerged, and their use is also steadily rising. Even so, the effects of SHS or eCigs during gestation remain limited. In the present study, we wanted to characterize the effects of SHS or eCig exposure at two different important gestational points during mouse pregnancy. C57/Bl6 mice were exposed to SHS or eCigs via a nose-only delivery system for 4 days (from 14.5 to 17.5 gestational days (dGA) or for 6 days (from 12.5 dGA to 17.5 dGA)). At the time of necropsy (18.5 dGA), placental and fetal weights were recorded, maternal blood pressure was determined, and a dipstick test to measure proteinuria was performed. Placental tissues were collected, and inflammatory molecules in the placenta were identified. Treatment with SHS showed the following: (1) a significant decrease in placental and fetal weights following four days of exposure, (2) higher systolic and diastolic blood pressure following six days of exposure, and (3) increased proteinuria after six days of exposure. Treatment with eCigs showed the following: (1) a significant decrease in placental weight and fetal weight following four or six days of exposure, (2) higher systolic and diastolic blood pressure following six days of exposure, and (3) increased proteinuria after six days of exposure. We also observed different inflammatory markers associated with the development of IUGR or PE. We conclude that the detrimental effects of SHS or eCig treatment coincide with the length of maternal exposure. These results could be beneficial in understanding the long-term effects of SHS or eCig exposure in the development of placental diseases.

Polystyrene microplastics disturb maternal glucose homeostasis and induce adverse pregnancy outcomes.

Pregnant women are a special group that is sensitive to adverse external stimuli, causing metabolic abnormalities and adverse pregnancy outcomes. Microplastics (MPs), an environmental pollutant widely used in various fields, can induce a variety of toxic responses in mammals. Recent studies verified an association between MPs and metabolic disorders. Our research built a gestational mouse model in which polystyrene microplastics (PS-MPs) of 1 µm size were consumed at concentrations of 0.1, 1, and 10 mg/L during pregnancy. Results indicated that PS-MPs induced placental malfunction and fetal growth retardation. Significant glucose disorders, decreased liver function, hepatic inflammation, and oxidative stress were also observed after PS-MPs exposure. The hepatic SIRT1/IRS1/PI3K pathway was inhibited in the 10 mg/L PS-MPs exposure group. Our study found that PS-MPs activated inflammatory response and oxidative stress by increasing hepatic lipopolysaccharide (LPS) that inhibited the hepatic SIRT1/IRS1/PI3K pathway, ultimately leading to insulin resistance, glucose metabolism disorders, and adverse pregnancy outcomes. This study provides a basis for preventing environment-related gestational diabetes and concomitant adverse pregnancy outcomes.

NBR1-dependent autophagy activation protects against environmental cadmium-evoked placental trophoblast senescence.

Cadmium (Cd), a well-established developmental toxicant, accumulates in the placentae and disrupts its structure and function. Population study found adverse pregnancy outcomes caused by environmental Cd exposure associated with cell senescence. However, the role of autophagy activation in Cd-induced placental cell senescence and its reciprocal mechanisms are unknown. In this study, we employed animal experiments, cell culture, and case-control study to investigate the above mentioned. We have demonstrated that exposure to Cd during gestation induces placental senescence and activates autophagy. Pharmacological and genetic interventions further exacerbated placental senescence induced by Cd through the suppression of autophagy. Conversely, activation of autophagy ameliorated Cd-induced placental senescence. Knockdown of NBR1 exacerbated senescence in human placental trophoblast cells. Further investigations revealed that NBR1 facilitated the degradation of p21 via LC3B. Our case-control study has demonstrated a positive correlation between placental senescence and autophagy activation in all-cause fetal growth restriction (FGR). These findings offer a novel perspective for mitigating placental aging and placental-origin developmental diseases induced by environmental toxicants.

The associations between maternal and fetal exposure to endocrine-disrupting chemicals and asymmetric fetal growth restriction: a prospective cohort study.

Recent evidence has revealed associations between endocrine-disrupting chemicals (EDCs) and placental insufficiency due to altered placental growth, syncytialization, and trophoblast invasion. However, no epidemiologic study has reported associations between exposure to EDCs and asymmetric fetal growth restriction (FGR) caused by placenta insufficiency. The aim of this study was to evaluate the association between EDC exposure and asymmetric FGR. This was a prospective cohort study including women admitted for delivery to the Maternal Fetal Center at Seoul St. Mary's Hospital between October 2021 and October 2022. Maternal urine and cord blood samples were collected, and the levels of bisphenol-A (BPA), monoethyl phthalates, and perfluorooctanoic acid in each specimen were analyzed. We investigated linear and non-linear associations between the levels of EDCs and fetal growth parameters, including the head circumference (HC)/abdominal circumference (AC) ratio as an asymmetric parameter. The levels of EDCs were compared between fetuses with and without asymmetric FGR. Of the EDCs, only the fetal levels of BPA showed a linear association with the HC/AC ratio after adjusting for confounding variables (ß = 0.003, p < 0.05). When comparing the normal growth and asymmetric FGR groups, the asymmetric FGR group showed significantly higher maternal and fetal BPA levels compared to the normal growth group (maternal urine BPA, 3.99 µg/g creatinine vs. 1.71 µg/g creatinine [p < 0.05]; cord blood BPA, 1.96 µg/L vs. -0.86 µg/L [p < 0.05]). In conclusion, fetal exposure levels of BPA show linear associations with asymmetric fetal growth patterns. High maternal and fetal exposure to BPA might be associated with asymmetric FGR.

Multi-organ developmental toxicity and its characteristics in fetal mice induced by dexamethasone at different doses, stages, and courses during pregnancy.

Dexamethasone is widely used in pregnant women at risk of preterm birth to reduce the occurrence of neonatal respiratory distress syndrome and subsequently reduce neonatal mortality. Studies have suggested that dexamethasone has developmental toxicity, but there is a notable absence of systematic investigations about its characteristics. In this study, we examined the effects of prenatal dexamethasone exposure (PDE) on mother/fetal mice at different doses (0.2, 0.4, or 0.8 mg/kg b.i.d), stages (gestational day 14-15 or 16-17) and courses (single- or double-course) based on the clinical practice. Results showed that PDE increased intrauterine growth retardation rate, and disordered the serum glucose, lipid and cholesterol metabolic phenotypes, and sex hormone level of mother/fetal mice. PDE was further discovered to interfere with the development of fetal lung, hippocampus and bone, inhibits steroid synthesis in adrenal and testis, and promotes steroid synthesis in the ovary and lipid synthesis in the liver, with significant effects observed at high dose, early stage and double course. The order of severity might be: ovary > lung > hippocampus/bone > others. Correlation analysis revealed that the decreased serum corticosterone and insulin-like growth factor 1 (IGF1) levels were closely related to PDE-induced low birth weight and abnormal multi-organ development in offspring. In conclusion, this study systematically confirmed PDE-induced multi-organ developmental toxicity, elucidated its characteristics, and proposed the potential "glucocorticoid (GC)-IGF1" axis programming mechanism. This research provided an experimental foundation for a comprehensive understanding of the effect and characteristics of dexamethasone on fetal multi-organ development, thereby guiding the application of "precision medicine" during pregnancy.

Cannabidiol Exposure During Rat Pregnancy Leads to Labyrinth-Specific Vascular Defects in the Placenta and Reduced Fetal Growth.

Introduction: Cannabis use is increasing among pregnant people, and cannabidiol (CBD), a constituent of cannabis, is often perceived as "natural" and "safe" as it is non-intoxicating. In utero, cannabis exposure is associated with negative health outcomes, including fetal growth restriction (FGR). The placenta supplies oxygen and nutrients to the fetus, and alterations in placental development can lead to FGR. While there has been some investigation into the effects of Δ9-THC, there has been limited investigation into the impacts of in utero gestational CBD exposure on the placenta. Methods: This study used histological and transcriptomic analysis of embryonic day (E)19.5 rat placentas from vehicle and CBD (3 mg/kg intraperitoneal injection) exposed pregnancies (E6.5-18.5). Results: The study revealed that pups from CBD-exposed pregnancies were 10% smaller, with the placentae displaying a decreased fetal blood space perimeter-to-area ratio. The transcriptomic analysis supported compromised angiogenesis and blood vessel formation with downregulated biological processes, including tube morphogenesis, angiogenesis, blood vessel morphogenesis, blood vessel development and vasculature development. Further, the CBD-exposed placentas displayed changed expression of glucose transporters (decreased GLUT1 and GR expression and increased GLUT3 expression). Transcriptomic analysis further revealed upregulated biological processes associated with metabolism. Finally, histological and transcriptomic analysis revealed altered cell populations within the placenta, specifically to syncytiotrophoblast layer II and endothelial cells. Conclusion: Together these results suggest that the structural changes in CDB-exposed placentae, including the altered expression of nutrient transporters and the changes to the placental fetal vasculature, may underlie the reduced fetal growth.

Gut microbiota contributes to bisphenol A-induced maternal intestinal and placental apoptosis, oxidative stress, and fetal growth restriction in pregnant ewe model by regulating gut-placental axis.

BACKGROUND: Bisphenol A (BPA) is an environmental contaminant with endocrine-disrupting properties that induce fetal growth restriction (FGR). Previous studies on pregnant ewes revealed that BPA exposure causes placental apoptosis and oxidative stress (OS) and decreases placental efficiency, consequently leading to FGR. Nonetheless, the response of gut microbiota to BPA exposure and its role in aggravating BPA-mediated apoptosis, autophagy, mitochondrial dysfunction, endoplasmic reticulum stress (ERS), and OS of the maternal placenta and intestine are unclear in an ovine model of gestation. RESULTS: Two pregnant ewe groups (n = 8/group) were given either a subcutaneous (sc) injection of corn oil (CON group) or BPA (5 mg/kg/day) dissolved in corn oil (BPA group) once daily, from day 40 to day 110 of gestation. The maternal colonic digesta and the ileum and placental tissue samples were collected to measure the biomarkers of autophagy, apoptosis, mitochondrial dysfunction, ERS, and OS. To investigate the link between gut microbiota and the BPA-induced FGR in pregnant ewes, gut microbiota transplantation (GMT) was conducted in two pregnant mice groups (n = 10/group) from day 0 to day 18 of gestation after removing their intestinal microbiota by antibiotics. The results indicated that BPA aggravates apoptosis, ERS and autophagy, mitochondrial function injury of the placenta and ileum, and gut microbiota dysbiosis in pregnant ewes. GMT indicated that BPA-induced ERS, autophagy, and apoptosis in the ileum and placenta are attributed to gut microbiota dysbiosis resulting from BPA exposure. CONCLUSIONS: Our findings indicate the underlying role of gut microbiota dysbiosis and gut-placental axis behind the BPA-mediated maternal intestinal and placental apoptosis, OS, and FGR. The findings further provide novel insights into modulating the balance of gut microbiota through medication or probiotics, functioning via the gut-placental axis, to alleviate gut-derived placental impairment or FGR. Video Abstract.

Effect of Anti-TNF Biologic Exposure During Pregnancy on Villitis of Unknown Etiology Diagnoses in Patients with Autoimmune Disease.

Tumor necrosis factor-α (TNF-α) antagonists are highly effective in controlling autoimmune diseases. This has led to speculation that they might also be useful in treating inflammatory placental conditions, such as chronic villitis of unknown etiology (VUE). VUE affects 10-15% of term placentas and is associated with recurrent fetal growth restriction (FGR) and pregnancy loss. We aimed to evaluate outcomes in patients with autoimmune diseases with and without anti-TNF-α biologic exposure during gestation. This retrospective cohort study compared pregnant women with autoimmune disease taking anti-TNF-α biologics (n = 89) to pregnant women with autoimmune disease but not taking a biologic (n = 53). We extracted data on all patients meeting our inclusion criteria over a 20-year period. Our primary outcome was the diagnosis of VUE by histology. Our secondary outcomes were maternal and neonatal complications such as preeclampsia, FGR, and neonatal intensive care admission. Kruskal-Wallis and chi-squared tests were performed as appropriate for statistical analysis. Maternal characteristics were comparable between groups, and there was no increase in adverse pregnancy outcomes based on anti-TNF-α treatment. Exposure to anti-TNF-α therapy had no significant effect on the incidence of VUE or other obstetric complications. Within the cohort exposed to anti-TNF-α biologics during pregnancy, the rate of VUE was 9.3%, which is comparable to the reported general population risk. Our data support the safety profile of biologic use in pregnancy.

N-acetylcysteine and Hydroxychloroquine Ameliorate ADMA-Induced Fetal Growth Restriction in Mice via Regulating Oxidative Stress and Autophagy.

Fetal growth restriction (FGR) seriously threatens perinatal health. The main cause of FGR is placental malperfusion, but the specific mechanism is still unclear, and there is no effective treatment for FGR. We constructed a FGR mouse model by adding exogenous asymmetric dimethylarginine (ADMA) through in vivo experiments and found that ADMA could cause placental dysplasia and induce the occurrence of FGR. Compared with the control group, reactive oxygen species (ROS) production in the placenta was increased in mice with FGR, and the expression of autophagy-related proteins p-AKT/AKT, p-mTOR/mTOR, and P62 was significantly decreased, while the expression of Beclin-1 and LC3-II was significantly increased in the FGR group. Furthermore, ADMA had a favorable effect in promoting the formation of autophagosomes. Hydroxychloroquine (HCQ) and N-acetylcysteine (NAC) improved ADMA-induced disorders of placental development and alleviated ADMA-induced FGR. This study found that ADMA could cause excessive autophagy of trophoblasts by increasing the level of oxidative stress, ultimately leading to the occurrence of FGR, and HCQ and NAC had therapeutic effects on ADMA-induced FGR.

Gestational exposure to 1-NP induces ferroptosis in placental trophoblasts via CYP1B1/ERK signaling pathway leading to fetal growth restriction.

Fetal growth restriction (FGR) is a prevalent complication in obstetrics, yet its exact aetiology remains unknown. Numerous studies suggest that the degradation of the living environment is a significant risk factor for FGR. 1-Nitropyrene (1-NP) is a widespread environmental pollutant as a representative substance of nitro-polycyclic aromatic hydrocarbons. In this study, we revealed that 1-NP induced FGR in fetal mice by constructing 1-NP exposed pregnant mice models. Intriguingly, we found that placental trophoblasts of 1-NP exposed mice exhibited significant ferroptosis, which was similarly detected in placental trophoblasts from human FGR patients. In this regard, we established a 1-NP exposed cell model in vitro using two human trophoblast cell lines, HTR8/SVneo and JEG-3. We found that 1-NP not only impaired the proliferation, migration, invasion and angiogenesis of trophoblasts, but also induced severe cellular ferroptosis. Meanwhile, the ferroptosis inhibitor ferrostatin-1 (Fer-1) effectively rescued 1-NP-induced trophoblast biological function impairment. Mechanistically, we revealed that 1-NP regulated ferroptosis by activating the ERK signaling pathway. Moreover, we innovatively revealed that CYP1B1 was essential for the activation of ERK signaling pathway induced by 1-NP. Overall, our study innovatively identified ferroptosis as a significant contributor to 1-NP induced trophoblastic functional impairment leading to FGR and clarified the specific mechanism by which 1-NP induced ferroptosis via the CYP1B1/ERK signaling pathway. Our study provided novel insights into the aetiology of FGR and revealed new mechanisms of reproductive toxicity of environmental pollutants.

Prenatal caffeine exposure induces autism-like behaviors in offspring under a high-fat diet via the gut microbiota-IL-17A-brain axis.

Prenatal caffeine exposure (PCE) is a significant contributor to intrauterine growth retardation (IUGR) in offspring, which has been linked to an increased susceptibility to autism spectrum disorder (ASD) later in life. Additionally, a high-fat diet (HFD) has been shown to exacerbate ASD-like behaviors, but the underlying mechanisms remain unclear. In this study, we first noted in the rat model of IUGR induced by PCE that male PCE offspring exhibited typical ASD-like behaviors post-birth, in contrast to their female counterparts. The female PCE offspring demonstrated only reduced abilities in free exploration and spatial memory. Importantly, both male and female PCE offspring displayed ASD-like behaviors when exposed to HFD. We further observed that PCE + HFD offspring exhibited damaged intestinal mucus barriers and disturbed gut microbiota, resulting in an increased abundance of Escherichia coli (E. coli). The induced differentiation of colonic Th17 cells by E. coli led to an increased secretion of IL-17A, which entered the hippocampus through peripheral circulation and caused synaptic damage in hippocampal neurons, ultimately resulting in ASD development. Our strain transplantation experiment suggested that E. coli-mediated increase of IL-17A may be the core mechanism of ASD with a fetal origin. In conclusion, PCE and HFD are potential risk factors for ASD, and E. coli-mediated IL-17A may play a crucial role in fetal-originated ASD through the gut-brain axis.

Bisphenol A induces placental ferroptosis and fetal growth restriction via the YAP/TAZ-ferritinophagy axis.

Exposure to bisphenol A (BPA) during gestation leads to fetal growth restriction (FGR), whereby the underlying mechanisms remain unknown. Here, we found that FGR patients showed higher levels of BPA in the urine, serum, and placenta; meanwhile, trophoblast ferroptosis was observed in FGR placentas, as indicated by accumulated intracellular iron, impaired antioxidant molecules, and increased lipid peroxidation products. To investigate the role of ferroptosis in placental and fetal growth, BPA stimulation was performed both in vivo and in vitro. BPA exposure during gestation was associated with FGR in mice; also, it induces ferroptosis in mouse placentas and human placental trophoblast. Pretreatment with ferroptosis inhibitor ferritin-1 (Fer-1) alleviated BPA-induced oxidative damage and cell death. Notably, BPA reduced the trophoblastic expression of Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ), which regulated tissue growth and organ size. YAP or TAZ siRNA enhanced BPA-induced ferroptosis, suggesting that trophoblast ferroptosis is dependent on YAP/TAZ downregulation after BPA stimulation. Consistently, the protein levels of YAP/TAZ were also reduced in FGR placentas. Further results revealed that silencing YAP/TAZ promoted BPA-induced ferroptosis through autophagy. Pretreatment with autophagy inhibitor chloroquine (CQ) attenuated BPA-induced trophoblast ferroptosis. Ferritinophagy, an autophagic degradation of ferritin (FTH1), was observed in FGR placentas. Similarly, BPA reduced the protein level of FTH1 in placental trophoblast. Pretreatment with iron chelator desferrioxamine (DFO) and NCOA4 (an autophagy cargo receptor) siRNA weakened the ferroptosis of trophoblast after exposure to BPA, indicating that autophagy mediates ferroptosis in BPA-stimulated trophoblast by degrading ferritin. In summary, ferroptosis was featured in BPA-associated FGR and trophoblast injury; the regulation of ferroptosis involved the YAP/TAZ-autophagy-ferritin axis.

Microbiota-indole 3-propionic acid-brain axis mediates abnormal synaptic pruning of hippocampal microglia and susceptibility to ASD in IUGR offspring.

BACKGROUND: Autism spectrum disorder (ASD) has been associated with intrauterine growth restriction (IUGR), but the underlying mechanisms are unclear. RESULTS: We found that the IUGR rat model induced by prenatal caffeine exposure (PCE) showed ASD-like symptoms, accompanied by altered gut microbiota and reduced production of indole 3-propionic acid (IPA), a microbiota-specific metabolite and a ligand of aryl hydrocarbon receptor (AHR). IUGR children also had a reduced serum IPA level consistent with the animal model. We demonstrated that the dysregulated IPA/AHR/NF-κB signaling caused by disturbed gut microbiota mediated the hippocampal microglia hyperactivation and neuronal synapse over-pruning in the PCE-induced IUGR rats. Moreover, postnatal IPA supplementation restored the ASD-like symptoms and the underlying hippocampal lesions in the IUGR rats. CONCLUSIONS: This study suggests that the microbiota-IPA-brain axis regulates ASD susceptibility in PCE-induced IUGR offspring, and supplementation of microbiota-derived IPA might be a promising interventional strategy for ASD with a fetal origin. Video Abstract.

Identifying critical windows of air pollution exposure during preconception and gestational period on birthweight: a prospective cohort study.

BACKGROUND: Few studies have assessed air pollution exposure association with birthweight during both preconception and gestational periods. METHODS: Leveraging a preconception cohort consisting of 14220 pregnant women and newborn children in Shanghai, China during 2016-2018, we aim to assess associations of NO2 and PM2.5 exposure, derived from high-resolution spatial-temporal models, during preconception and gestational periods with outcomes including term birthweight, birthweight Z-score, small-for-gestational age (SGA) and large-for-gestational age (LGA). Linear and logistic regressions were used to estimate 3-month preconception and trimester-averaged air pollution exposure associations; and distributed lag models (DLM) were used to identify critical exposure windows at the weekly resolution from preconception to delivery. Two-pollutant models and children's sex-specific associations were explored. RESULTS: After controlling for covariates, one standard deviation (SD) (11.5 µg/m3, equivalent to 6.1 ppb) increase in NO2 exposure during the second and the third trimester was associated with 13% (95% confidence interval: 2 - 26%) and 14% (95% CI: 1 - 29%) increase in SGA, respectively; and one SD (9.6 µg/m3) increase in PM2.5 exposure during the third trimester was associated with 15% (95% CI: 1 - 31%) increase in SGA. No association have been found for outcomes of birthweight, birthweight Z-score and LGA. DLM found that gestational weeks 22-32 were a critical window, when NO2 exposure had strongest associations with SGA. The associations of air pollution exposure tended to be stronger in female newborns than in male newborns. However, no significant associations of air pollution exposure during preconception period on birthweight outcomes were found. CONCLUSION: Consistent with previous studies, we found that air pollution exposure during mid-to-late pregnancy was associated with adverse birthweight outcomes.

Obeticholic acid alleviates intrauterine growth restriction induced by di-ethyl-hexyl phthalate in pregnant female mice by improving bile acid disorder.

Di-(2-ethylhexyl)-phthalate (DEHP) is a ubiquitous environmental pollutant and is widely used in industrial plastics. Intrahepatic cholestasis of pregnancy (ICP), distinguished by maternal pruritus and elevated serum bile acid levels, is linked to unfavorable pregnancy consequences. Few studies have investigated the potential effect of gestational DEHP exposure on the cholestasis in pregnant female mice, and the underlying mechanisms remain unclear. In the present study, a mouse model of cholestasis during pregnancy was established by DEHP exposure. We found that DEHP induces elevated bile acid levels by affecting bile acid synthesis and transporter receptor expression in the maternal liver and placenta of pregnant female mice, ultimately leading to intrauterine growth restriction (IUGR). In addition, DEHP changed the bile acid composition of maternal serum and liver as well as placenta and amniotic fluid in pregnant female mice; Importantly, we found that DEHP down-regulates the expression of farnesoid X receptor (FXR), which is considered to be a bile acid receptor. FXR agonist obeticholic acid (OCA) effectively alleviated the adverse effects of DEHP on pregnant female mice. While, OCA itself had no adverse effects on normal pregnant female mice. In summary, DEHP could induces bile acid disorder and IUGR in pregnant female mice by affect FXR, which was reversed by OCA.

Regulation of sexually dimorphic placental adaptation in LPS exposure-induced intrauterine growth restriction.

BACKGROUND: Sexual dimorphism in placental physiology affects the functionality of placental adaptation during adverse pregnancy. Defects of placental function compromise fetal programming, affecting the offspring's adult life. However, studies focusing on the relationship between sex-specific placental adaptation and consequent fetal maldevelopment under sub-optimal uterus milieu are still elusive. METHODS: Here, we investigated the effects of maternal lipopolysaccharide (LPS) exposure between placental sex. Pregnant ICR mice received intraperitoneal injection of phosphate-buffered saline or 100, 200, and 400 µg/kg LPS on the gestational day (GD) 15.5. To determine whether prenatal maternal LPS exposure resulted in complicated pregnancy outcomes, survival rate of embryos was calculated and the growth of embryos and placentas was examined. To elucidate global transcriptomic changes occurring in the placenta, total RNA-sequencing (RNA-seq) was performed in female and male placentas. RESULTS: LPS administration induced placental inflammation in both sexes at GD 17.5. Prenatal infection resulted in growth retardation in both sexes of embryos, and especially more prevalently in male. Impaired placental development was observed in a sex-specific manner. LPS 400 µg/kg reduced the percentage area of the labyrinth in females and junctional zone in males, respectively. RNA-sequencing revealed widespread sexually dimorphic transcriptional changes in placenta. In particular, representative changes were involved in biological processes such as trophoblast differentiation, nutrient/ion transporter, pregnancy, and immune system. CONCLUSIONS: Our results present the sexually dimorphic responses of placental physiology in intrauterine growth restriction model and provide tentative relationship further to be elucidated between sex-biased placental functional change and long-term effects on the offspring's later life.

Paternal lipopolysaccharide exposure induced intrauterine growth restriction via the inactivation of placental MEST/PI3K/AKT pathway in mice.

Maternal lipopolysaccharide (LPS) exposure during pregnancy has been related to IUGR. Here, we explored whether paternal LPS exposure before mating impaired fetal development. All male mice except controls were intraperitoneally injected with LPS every other day for a total of five injections. The next day after the last LPS, male mice were mated with untreated female mice. Interestingly, fetal weight and crown-rump length were reduced, while the incidence of IUGR was increased in paternal LPS exposure group. Additionally, paternal LPS exposure leaded to poor placental development through causing cell proliferation inhibition and apoptosis. Additional experiment demonstrated that the inactivation of placental PI3K/AKT pathway might be involved in paternal LPS-induced cell proliferation inhibition and apoptosis of trophoblast cells. Furthermore, the mRNA and protein levels of mesoderm specific transcript (MEST), a maternally imprinted gene with paternal expression, were significantly decreased in mouse placentas from paternal LPS exposure. Further analysis showed that paternal LPS exposure caused the inactivation of placental PI3K/AKT pathway and then cell proliferation inhibition and apoptosis might be via down-regulating placental MEST. Overall, our results provide evidence that paternal LPS exposure causes poor placental development and subsequently IUGR may be via down-regulating MEST/PI3K/AKT pathway, and then inducing cell proliferation inhibition and apoptosis in placentas.