Maternal intrahepatic cholestasis of pregnancy and neurodevelopmental conditions in offspring: A population-based cohort study of 2 million Swedish children.

BACKGROUND: Intrahepatic cholestasis of pregnancy (ICP) is the most common obstetric liver disorder and is associated with an increased risk of iatrogenic preterm birth and adverse infant outcomes. Hence, there are several plausible pathways through which ICP could affect offspring neurodevelopment. However, to the best of our knowledge, no studies have investigated these associations. Thus, we aimed to determine whether ICP is associated with offspring neurodevelopmental conditions. METHODS AND FINDINGS: In this Swedish register-based cohort study, we included singleton non-adopted children born in Sweden between the 1st of January 1987 and the 31st of December 2010, who were resident in Sweden >5 years, with no missing covariate information, which we followed until the 31st of December 2016. Maternal ICP diagnosis and the date of the initial diagnosis during pregnancy were obtained from the National Patient Register. Offspring diagnoses of attention deficit/hyperactivity disorder (ADHD), autism, or intellectual disability were obtained from the National Patient Register, and the dispensation of ADHD medications were obtained from the Prescribed Drug Register. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression while controlling for observed confounders and unobserved confounders shared among full siblings and maternal full cousins. A total of 2,375,856 children were included in the study; 81.6% of them were of Nordic origin, and 51.4% were male. Of these, 10,378 (0.44%) were exposed to ICP. During a median of 18 years follow-up (interquartile range 11 to 24), 143,746 (6.05%) of children were diagnosed with a neurodevelopmental condition. After adjusting for child's sex, birth year, birth month, maternal age, highest parental education level, maternal birth country, birth order, maternal psychiatric history, ICP was associated with increased odds of offspring neurodevelopmental conditions (OR 1.22, 95% CI 1.13 to 1.31), particularly among those exposed to early-onset ICP (OR 2.38, 95% CI 1.71 to 3.30) as compared to ICP diagnosed after reaching term (≥37 weeks of gestation) (OR 1.08, 95% CI 0.97 to 1.20). The findings of early-onset ICP were consistent in family-based analyses. Within-family comparisons of full maternal cousins yielded an OR of 2.99 (95% CI 1.48 to 6.04), and comparisons of full siblings showed an OR of 1.92 (95% CI 0.92 to 4.02), though the latter was less precise. The findings were consistent across specific neurodevelopmental conditions and different analytical approaches. The primary limitations of this study included its observational design, the absence of data on ICP therapeutics, and the lack of bile acid measures. CONCLUSIONS: In this study, we observed that exposure to ICP during gestation is associated with an increased likelihood of neurodevelopmental conditions in offspring, particularly in cases of early-onset ICP. Further studies are warranted to better understand the role of early-ICP in offspring neurodevelopment.

Acetaminophen Use During Pregnancy and Children's Risk of Autism, ADHD, and Intellectual Disability.

Importance: Several studies suggest that acetaminophen (paracetamol) use during pregnancy may increase risk of neurodevelopmental disorders in children. If true, this would have substantial implications for management of pain and fever during pregnancy. Objective: To examine the associations of acetaminophen use during pregnancy with children's risk of autism, attention-deficit/hyperactivity disorder (ADHD), and intellectual disability. Design, Setting, and Participants: This nationwide cohort study with sibling control analysis included a population-based sample of 2 480 797 children born in 1995 to 2019 in Sweden, with follow-up through December 31, 2021. Exposure: Use of acetaminophen during pregnancy prospectively recorded from antenatal and prescription records. Main Outcomes and Measures: Autism, ADHD, and intellectual disability based on International Classification of Diseases, Ninth Revision and International Classification of Diseases, Tenth Revision codes in health registers. Results: In total, 185 909 children (7.49%) were exposed to acetaminophen during pregnancy. Crude absolute risks at 10 years of age for those not exposed vs those exposed to acetaminophen were 1.33% vs 1.53% for autism, 2.46% vs 2.87% for ADHD, and 0.70% vs 0.82% for intellectual disability. In models without sibling control, ever-use vs no use of acetaminophen during pregnancy was associated with marginally increased risk of autism (hazard ratio [HR], 1.05 [95% CI, 1.02-1.08]; risk difference [RD] at 10 years of age, 0.09% [95% CI, -0.01% to 0.20%]), ADHD (HR, 1.07 [95% CI, 1.05-1.10]; RD, 0.21% [95% CI, 0.08%-0.34%]), and intellectual disability (HR, 1.05 [95% CI, 1.00-1.10]; RD, 0.04% [95% CI, -0.04% to 0.12%]). To address unobserved confounding, matched full sibling pairs were also analyzed. Sibling control analyses found no evidence that acetaminophen use during pregnancy was associated with autism (HR, 0.98 [95% CI, 0.93-1.04]; RD, 0.02% [95% CI, -0.14% to 0.18%]), ADHD (HR, 0.98 [95% CI, 0.94-1.02]; RD, -0.02% [95% CI, -0.21% to 0.15%]), or intellectual disability (HR, 1.01 [95% CI, 0.92-1.10]; RD, 0% [95% CI, -0.10% to 0.13%]). Similarly, there was no evidence of a dose-response pattern in sibling control analyses. For example, for autism, compared with no use of acetaminophen, persons with low (<25th percentile), medium (25th-75th percentile), and high (>75th percentile) mean daily acetaminophen use had HRs of 0.85, 0.96, and 0.88, respectively. Conclusions and Relevance: Acetaminophen use during pregnancy was not associated with children's risk of autism, ADHD, or intellectual disability in sibling control analysis. This suggests that associations observed in other models may have been attributable to familial confounding.

Random capillary glucose levels throughout pregnancy, obstetric and neonatal outcomes, and long-term neurodevelopmental conditions in children: a group-based trajectory analysis.

BACKGROUND: Gestational diabetes mellitus (GDM) is associated with both short- and long-term risks, although it is unknown if risks vary by severity, timing, and duration of gestational hyperglycemia. We aimed to identify trajectories of random capillary glucose (RCG) levels throughout pregnancy and assess their associations with both obstetric/neonatal outcomes and children's risk of neurodevelopmental conditions (NDCs) (i.e., autism, intellectual disability, and attention-deficit/hyperactivity disorders [ADHD]). METHODS: A population-based cohort study was conducted involving 76,228 children born to 68,768 mothers without pregestational diabetes. Group-based trajectory modeling was utilized to identify distinct glucose trajectories across RCG values throughout the course of pregnancy. The associations between these trajectory groups and obstetric/neonatal outcomes as well as children's NDCs were then assessed using generalized estimating equation models with a logit link. The Benjamini-Hochberg (BH) procedure was employed to adjust P-values for multiple comparisons, controlling the false discovery rate (FDR). RESULTS: Five distinct glucose trajectory groups were identified, each with varying percentages diagnosed with GDM. Their associations with obstetric/neonatal outcomes as well as children's NDCs varied. For example, when compared to the "Persistently Low" group, other groups exhibited varying degrees of increased risk for large-for-gestational-age babies, with the exception of the "High in Early Pregnancy" group. Compared to the "Persistently Low" group, all other trajectory groups were associated with NDC outcomes, except the "High in Mid-Pregnancy" group. However, none of the associations with offspring NDCs remained significant after accounting for the FDR correction. CONCLUSIONS: Persistent high glucose levels or moderately elevated glucose levels throughout pregnancy, as well as transient states of hyperglycemia in early or mid-pregnancy, were found to be associated with increased risks of specific obstetric and neonatal complications, and potentially offspring NDCs. These risks varied depending on the severity, timing, duration, and management of hyperglycemia. The findings underscore the need for continuous surveillance and individualized management strategies for women displaying different glucose trajectories during pregnancy. Limitations such as potential residual confounding, the role of mediators, and small sample size should be addressed in future studies.

Rates of maternal weight gain over the course of pregnancy and offspring risk of neurodevelopmental disorders.

BACKGROUND: Previous studies have suggested that gestational weight gain (GWG) outside an optimal range increases the risks of neurodevelopmental disorders (NDDs) in offspring including autism spectrum disorder (ASD), intellectual disability (ID), and attention deficit/hyperactivity disorder (ADHD). The sequential development of the fetal brain suggests that its vulnerability may vary depending on the timing of exposure. Therefore, we aimed to investigate the associations of not only gestational age-standardized total GWG (GWG z-scores) but also the rate of GWG (RGWG) in the second and third trimesters with risks of NDDs in offspring. METHODS: In this population-based cohort study, we used maternal weight data from antenatal care records collected for 57,822 children born to 53,516 mothers between 2007 and 2010 in the Stockholm Youth Cohort. Children were followed from 2 years of age to December 31, 2016. GWG z-scores and RGWG (kg/week) in the second and third trimesters were considered as continuous variables in cox regression models, clustered on maternal identification numbers. Nonlinear relationships were accommodated using restricted cubic splines with 3 knots. RGWG were also categorized according to the 2009 US Institute of Medicine (IOM) guidelines for optimal GWG. According to the IOM guidelines, the optimal rate of GWG for the second and third trimesters for underweight, normal weight, overweight, and obese categories were 0.44-0.58, 0.35-0.50, 0.23-0.33, and 0.17-0.27 kg/week, respectively. RESULTS: During a mean follow-up of 5.4 years (until children were on average 7.4 years old), 2205 (3.8%) children were diagnosed with NDDs, of which 1119 (1.9%) received a diagnosis of ASD, 1353 (2.3%) ADHD, and 270 (0.5%) ID. We observed a J-shaped association between total GWG z-score and offspring risk of NDDs, with higher total GWG (GWG z-score = 2) associated with 19% increased risk of any NDD (95% CI = 3-37%) and lower total GWG (GWG z-score = - 2) associated with 12% increased risk of any NDDs (95% CI = 2-23%), compared to the reference (GWG z-score = 0). In the second trimester, lower RGWG (0.25 kg/week) was associated with a 9% increased risk of any NDD diagnosis (95% CI = 4-15%) compared to the median of 0.57 kg/week, with no apparent relationship between higher RGWG and risk of NDDs. In the third trimester, there was no apparent association between lower RGWG and risk of NDDs, though higher RGWG (1 kg/week) was associated with a 28% increased risk of NDD diagnosis (95% CI = 16-40%), compared to the median (0.51 kg/week). When considering categorized RGWG, we found that slow weight gain in the second trimester followed by rapid weight gain in the third trimester most significantly increased the risk of ADHD (HRadjusted = 1.55, 1.13-2.13) and ID (HRadjusted = 2.53, 1.15-5.55) in offspring. The main limitations of our study are the relatively few years for which detailed GWG data were available and the relatively short follow-up for the outcomes, limiting power to detect associations and misclassifying children who receive an NDD diagnosis later in childhood. CONCLUSIONS: The relationship between maternal weight gain and children's risk of NDDs varied according to timing in pregnancy, with the greatest risks associated with slow weight gain in the second trimester and rapid weight gain in the third trimester.

Autonomic function and inflammation in pregnant women participating in a randomized controlled study of Mindfulness Based Childbirth and Parenting.

BACKGROUND: Pregnancy and childbirth are significant events in many women's lives, and the prevalence of depressive symptoms increases during this vulnerable period. Apart from well documented cognitive, affective, and somatic symptoms, stress and depression are associated with physiological changes, such as reduced heart-rate variability (HRV) and activation of the inflammatory response system. Mindfulness Based Interventions may potentially have an effect on both HRV, inflammatory biomarkers, and self-assessed mental health. Therefore, the aim of this study was to assess the effects of a Mindfulness Childbirth and Parenting (MBCP) intervention on HRV, serum inflammatory marker levels, through an RCT study design with an active control group. METHODS: This study is a sub-study of a larger RCT, where significant intervention effects were found on perinatal depression (PND) and perceived stress. Participants were recruited through eight maternity health clinics in Stockholm, Sweden. In this sub-study, we included altogether 80 women with increased risk for PND, and blood samples and HRV measures were available from 60 of the participants (26 in the intervention and 34 in the control group). RESULTS: Participants who received MBCP reported a significantly larger reduction in perceived stress and a significantly larger increase in mindfulness, compared to participants who received the active control treatment. However, in this sub-study, the intervention had no significant effect on PND, inflammatory serum markers or measures of HRV. CONCLUSIONS: No significant differences were found regarding changes in HRV measures and biomarkers of inflammation, larger studies may be needed in the future. TRIAL REGISTRATION: ClinicalTrials.gov ID:  NCT02441595 . Registered 12 May 2015 - Retrospectively registered.

Developmental vitamin D and autism spectrum disorders: findings from the Stockholm Youth Cohort.

Animal studies indicate that early life vitamin D is crucial for proper neurodevelopment. Few studies have examined whether maternal and neonatal vitamin D concentrations influence risk of autism spectrum disorders (ASD). Participants were sampled from the Stockholm Youth Cohort, a register-based cohort in Sweden. Concentrations of total 25-hydroxyvitamin D (25OHD) were assessed from maternal and neonatal biosamples using a highly sensitive liquid chromatography tandem mass spectrometry method. The maternal sample consisted of 449 ASD cases and 574 controls, the neonatal sample: 1399 ASD cases and 1607 controls; and the paired maternal-neonatal sample: 340 ASD cases and 426 controls. Maternal 25OHD was not associated with child ASD in the overall sample. However, in Nordic-born mothers, maternal 25OHD insufficiency (25 - <50 nmol/L) at ~11 weeks gestation was associated with 1.58 times higher odds of ASD (95% CI: 1.00, 2.49) as compared with 25OHD sufficiency (≥50 nmol/L). Neonatal 25OHD < 25 nmol/L was associated with 1.33 times higher odds of ASD (95% CI: 1.02, 1.75) as compared with 25OHD ≥ 50 nmol/L. Sibling-matched control analyses indicated these associations were not likely due to familial confounding. Children with both maternal 25OHD and neonatal 25OHD below the median had 1.75 (95% CI: 1.08, 2.86) times the odds of ASD compared with children with maternal and neonatal 25OHD both below the median. Our results are consistent with an increasing body of evidence suggesting that vitamin D concentrations in early life may be associated with increased risk of neurodevelopmental disorders including ASD.

Discovery of thymosin ß4 as a human exerkine and growth factor.

Skeletal muscle is an endocrine organ secreting exercise-induced factors (exerkines), which play a pivotal role in interorgan cross talk. Using mass spectrometry (MS)-based proteomics, we characterized the secretome and identified thymosin ß4 (TMSB4X) as the most upregulated secreted protein in the media of contracting C2C12 myotubes. TMSB4X was also acutely increased in the plasma of exercising humans irrespective of the insulin resistance condition or exercise mode. Treatment of mice with TMSB4X did not ameliorate the metabolic disruptions associated with diet induced-obesity, nor did it enhance muscle regeneration in vivo. However, TMSB4X increased osteoblast proliferation and neurite outgrowth, consistent with its WADA classification as a prohibited growth factor. Therefore, we report TMSB4X as a human exerkine with a potential role in cellular cross talk.

Branched-chain amino acid metabolism is regulated by ERRα in primary human myotubes and is further impaired by glucose loading in type 2 diabetes.

AIMS/HYPOTHESIS: Increased levels of branched-chain amino acids (BCAAs) are associated with type 2 diabetes pathogenesis. However, most metabolomic studies are limited to an analysis of plasma metabolites under fasting conditions, rather than the dynamic shift in response to a metabolic challenge. Moreover, metabolomic profiles of peripheral tissues involved in glucose homeostasis are scarce and the transcriptomic regulation of genes involved in BCAA catabolism is partially unknown. This study aimed to identify differences in circulating and skeletal muscle BCAA levels in response to an OGTT in individuals with normal glucose tolerance (NGT) or type 2 diabetes. Additionally, transcription factors involved in the regulation of the BCAA gene set were identified. METHODS: Plasma and vastus lateralis muscle biopsies were obtained from individuals with NGT or type 2 diabetes before and after an OGTT. Plasma and quadriceps muscles were harvested from skeletal muscle-specific Ppargc1a knockout and transgenic mice. BCAA-related metabolites and genes were assessed by LC-MS/MS and quantitative RT-PCR, respectively. Small interfering RNA and adenovirus-mediated overexpression techniques were used in primary human skeletal muscle cells to study the role of PPARGC1A and ESRRA in the expression of the BCAA gene set. Radiolabelled leucine was used to analyse the impact of oestrogen-related receptor α (ERRα) knockdown on leucine oxidation. RESULTS: Impairments in BCAA catabolism in people with type 2 diabetes under fasting conditions were exacerbated after a glucose load. Branched-chain keto acids were reduced 37-56% after an OGTT in the NGT group, whereas no changes were detected in individuals with type 2 diabetes. These changes were concomitant with a stronger correlation with glucose homeostasis biomarkers and downregulated expression of branched-chain amino acid transaminase 2, branched-chain keto acid dehydrogenase complex subunits and 69% of downstream BCAA-related genes in skeletal muscle. In primary human myotubes overexpressing peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α, encoded by PPARGC1A), 61% of the analysed BCAA genes were upregulated, while 67% were downregulated in the quadriceps of skeletal muscle-specific Ppargc1a knockout mice. ESRRA (encoding ERRα) silencing completely abrogated the PGC-1α-induced upregulation of BCAA-related genes in primary human myotubes. CONCLUSIONS/INTERPRETATION: Metabolic inflexibility in type 2 diabetes impacts BCAA homeostasis and attenuates the decrease in circulating and skeletal muscle BCAA-related metabolites after a glucose challenge. Transcriptional regulation of BCAA genes in primary human myotubes via PGC-1α is ERRα-dependent.

Psychiatric comorbidity among women with endometriosis: nationwide cohort study in Sweden.

BACKGROUND: Endometriosis is a common gynecologic condition affecting women of reproductive age. It has been linked with greater rates of depression and anxiety in small, cross-sectional, and clinical studies. Other studies have reported that women with endometriosis have increased risk of bipolar disorder. These reports suggest that psychiatric disorders might be more common among women with endometriosis, contributing to increased burden of mental ill-health in this population of women. However, this hypothesis has not been adequately studied. OBJECTIVES: In this population-based study, we investigated the overall psychiatric comorbidity among women with endometriosis, and the role of familial liability. STUDY DESIGN: Several Swedish national registers were linked and used to follow all women born in Sweden in 1973-1990 for diagnosed psychiatric disorders and endometriosis from age 14 years until year 2016. Sibling comparison analyses were performed in a subsample of 173,650 families. RESULTS: After adjustment for birth characteristics and education, women with endometriosis had an increased risk of being later diagnosed with depressive-, anxiety and stress-related disorders, alcohol/drug dependence, and attention-deficit hyperactivity disorder compared with the general population and with their sisters without endometriosis. The adjusted hazard ratios ranged from 1.56 (95% confidence interval, 1.29-1.88) for depressive disorders to 1.98 (95% confidence interval, 1.34-2.93) for attention-deficit hyperactivity disorder in the sibling analysis. Also, women with previous affective psychotic disorders, depressive-, anxiety and stress-related disorders, eating disorders, personality disorders, and attention-deficit hyperactivity disorder were more likely to be later diagnosed with endometriosis. The adjusted hazard ratios ranged from 1.51 (95% confidence interval, 1.30-1.76) for depressive disorders to 1.93 (95% confidence interval, 1.47-2.52) for personality disorders. CONCLUSION: These findings reveal a high degree of comorbidity between endometriosis and many psychiatric disorders that was not entirely explained by shared familial confounding. Clinical practice may consider psychosocial support to women with endometriosis and treating them from a multidisciplinary perspective.

Systemic inflammation and intelligence in early adulthood and subsequent risk of schizophrenia and other non-affective psychoses: a longitudinal cohort and co-relative study.

BACKGROUND: Schizophrenia is associated with impaired neurodevelopment as indexed by lower premorbid IQ. We examined associations between erythrocyte sedimentation rate (ESR), a marker of low-grade systemic inflammation, IQ, and subsequent schizophrenia and other non-affective psychoses (ONAP) to elucidate the role of neurodevelopment and inflammation in the pathogenesis of psychosis. METHODS: Population-based data on ESR and IQ from 638 213 Swedish men assessed during military conscription between 1969 and 1983 were linked to National Hospital Discharge Register for hospitalisation with schizophrenia and ONAP. The associations of ESR with IQ (cross-sectional) and psychoses (longitudinal) were investigated using linear and Cox-regression. The co-relative analysis was used to examine effects of shared familial confounding. We examined mediation and moderation of effect between ESR and IQ on psychosis risk. RESULTS: Baseline IQ was associated with subsequent risk of schizophrenia (adjusted HR per 1-point increase in IQ = 0.961; 95% confidence interval (CI) 0.960-0.963) and ONAP (adjusted HR = 0.973; 95% CI 0.971-0.975). Higher ESR was associated with lower IQ in a dose-response fashion. High ESR was associated with increased risk for schizophrenia (adjusted HR = 1.14; 95% CI 1.01-1.28) and decreased risk for ONAP (adjusted HR = 0.85; 95% CI 0.74-0.96), although these effects were specific to one ESR band (7-10 mm/hr). Familial confounding explained ESR-IQ but not ESR-psychoses associations. IQ partly mediated the ESR-psychosis relationships. CONCLUSIONS: Lower IQ is associated with low-grade systemic inflammation and with an increased risk of schizophrenia and ONAP in adulthood. Low-grade inflammation may influence schizophrenia risk by affecting neurodevelopment. Future studies should explore the differential effects of inflammation on different types of psychosis.

Birth seasonality and risk of autism spectrum disorder.

Season of birth has been hypothesized to be a risk factor for autism spectrum disorder (ASD). However, the evidence has been mixed and limited due to methodological challenges. We examine ASD birth trends for 5,464,628 births across 5 countries. ASD birth prevalence data were obtained from the International Collaboration for Autism Registry Epidemiology database, including children born in Denmark, Finland, Norway, Sweden, and Western Australia. Empirical mode decomposition and cosinor modeling were used to assess seasonality. We show seasonal variation in ASD births for the countries of Finland and Sweden. There was a modest increase in risk for children born in the fall and a modest decrease in risk for children born in the spring. Solar radiation levels around conception and the postnatal period were inversely correlated with seasonal trends in ASD risk. In the first multinational study of birth seasonality of ASD, there was evidence supporting the presence of seasonal trends in Finland and Sweden. The observations that risk was highest for fall births (i.e., conceived in the winter) and lowest for spring births (i.e., conceived in the summer), and sunlight levels during critical neurodevelopmental periods explained much of the seasonal trends, are consistent with the hypothesis that a seasonally fluctuating risk factor may influence risk of ASD.

H1N1 influenza virus induces narcolepsy-like sleep disruption and targets sleep-wake regulatory neurons in mice.

An increased incidence in the sleep-disorder narcolepsy has been associated with the 2009-2010 pandemic of H1N1 influenza virus in China and with mass vaccination campaigns against influenza during the pandemic in Finland and Sweden. Pathogenetic mechanisms of narcolepsy have so far mainly focused on autoimmunity. We here tested an alternative working hypothesis involving a direct role of influenza virus infection in the pathogenesis of narcolepsy in susceptible subjects. We show that infection with H1N1 influenza virus in mice that lack B and T cells (Recombinant activating gene 1-deficient mice) can lead to narcoleptic-like sleep-wake fragmentation and sleep structure alterations. Interestingly, the infection targeted brainstem and hypothalamic neurons, including orexin/hypocretin-producing neurons that regulate sleep-wake stability and are affected in narcolepsy. Because changes occurred in the absence of adaptive autoimmune responses, the findings show that brain infections with H1N1 virus have the potential to cause per se narcoleptic-like sleep disruption.

Communication skills training enhances nurses' ability to respond with empathy to parents' emotions in a neonatal intensive care unit.

AIM: We quantitatively analysed the effect of a course in communication on the content of nurse-parent encounters and the ability of nurses to respond to the empathic needs of parents in a level III neonatal intensive care unit. METHODS: We evaluated 36 and 45 nurse-parent encounters audio recorded before and after 13 neonatal nurses attended a communication course. The number of empathic opportunities, the nurses' responses to these and the ways they involved parents in their infants' care were studied. RESULTS: Both before and after the course, the nurses talked more than the parents during the conversations. This nurse-centredness decreased after the course. The use of empathic or exploring responses to empathic opportunities increased from 19.9 ± 9.0% to 53.8 ± 8.9% (p = 0.027), whereas ignoring the feelings of the parents or giving inadequate advice decreased from 63.0 ± 10.0% to 27.5 ± 8.4% (p = 0.043) after the course. Use of statements expressing caring for the parents and encouragement for parents to participate in the care of their infant increased after the course (p = 0.0034 and p = 0.043, respectively). The nurses felt the course was very useful for their profession. CONCLUSION: A course in communication techniques improved nurses' ability to respond to parents' feelings with empathy.

Transcriptional derepression of the ERVWE1 locus following influenza A virus infection.

UNLABELLED: Syncytin-1, a fusogenic protein encoded by a human endogenous retrovirus of the W family (HERV-W) element (ERVWE1), is expressed in the syncytiotrophoblast layer of the placenta. This locus is transcriptionally repressed in adult tissues through promoter CpG methylation and suppressive histone modifications. Whereas syncytin-1 appears to be crucial for the development and functioning of the human placenta, its ectopic expression has been associated with pathological conditions, such as multiple sclerosis and schizophrenia. We previously reported on the transactivation of HERV-W elements, including ERVWE1, during influenza A/WSN/33 virus infection in a range of human cell lines. Here we report the results of quantitative PCR analyses of transcripts encoding syncytin-1 in both cell lines and primary fibroblast cells. We observed that spliced ERVWE1 transcripts and those encoding the transcription factor glial cells missing 1 (GCM1), acting as an enhancer element upstream of ERVWE1, are prominently upregulated in response to influenza A/WSN/33 virus infection in nonplacental cells. Knockdown of GCM1 by small interfering RNA followed by infection suppressed the transactivation of ERVWE1. While the infection had no influence on CpG methylation in the ERVWE1 promoter, chromatin immunoprecipitation assays detected decreased H3K9 trimethylation (H3K9me3) and histone methyltransferase SETDB1 levels along with influenza virus proteins associated with ERVWE1 and other HERV-W loci in infected CCF-STTG1 cells. The present findings suggest that an exogenous influenza virus infection can transactivate ERVWE1 by increasing transcription of GCM1 and reducing H3K9me3 in this region and in other regions harboring HERV-W elements. IMPORTANCE: Syncytin-1, a protein encoded by the env gene in the HERV-W locus ERVWE1, appears to be crucial for the development and functioning of the human placenta and is transcriptionally repressed in nonplacental tissues. Nevertheless, its ectopic expression has been associated with pathological conditions, such as multiple sclerosis and schizophrenia. In the present paper, we report findings suggesting that an exogenous influenza A virus infection can transactivate ERVWE1 by increasing the transcription of GCM1 and reducing the repressive histone mark H3K9me3 in this region and in other regions harboring HERV-W elements. These observations have implications of potential relevance for viral pathogenesis and for conditions associated with the aberrant transcription of HERV-W loci.

Maternal hospitalization with infection during pregnancy and risk of autism spectrum disorders.

Animal models indicate that maternal infection during pregnancy can result in behavioral abnormalities and neuropathologies in offspring. We examined the association between maternal inpatient diagnosis with infection during pregnancy and risk of ASD in a Swedish nationwide register-based birth cohort born 1984-2007 with follow-up through 2011. In total, the sample consisted of 2,371,403 persons with 24,414 ASD cases. Infection during pregnancy was defined from ICD codes. In the sample, 903 mothers of ASD cases (3.7%) had an inpatient diagnosis of infection during pregnancy. Logistic regression models adjusted for a number of covariates yielded odds ratios indicating approximately a 30% increase in ASD risk associated with any inpatient diagnosis of infection. Timing of infection did not appear to influence risk in the total Swedish population, since elevated risk of ASD was associated with infection in all trimesters. In a subsample analysis, infections were associated with greater risk of ASD with intellectual disability than for ASD without intellectual disability. The present study adds to the growing body of evidence, encompassing both animal and human studies, that supports possible immune-mediated mechanisms underlying the etiology of ASD.

Behavioral disturbances in adult mice following neonatal virus infection or kynurenine treatment--role of brain kynurenic acid.

Exposure to infections in early life is considered a risk-factor for developing schizophrenia. Recently we reported that a neonatal CNS infection with influenza A virus in mice resulted in a transient induction of the brain kynurenine pathway, and subsequent behavioral disturbances in immune-deficient adult mice. The aim of the present study was to investigate a potential role in this regard of kynurenic acid (KYNA), an endogenous antagonist at the glycine site of the N-methyl-D-aspartic acid (NMDA) receptor and at the cholinergic α7 nicotinic receptor. C57BL/6 mice were injected i.p. with neurotropic influenza A/WSN/33 virus (2400 plaque-forming units) at postnatal day (P) 3 or with L-kynurenine (2×200 mg/kg/day) at P7-16. In mice neonatally treated with L-kynurenine prepulse inhibition of the acoustic startle, anxiety, and learning and memory were also assessed. Neonatally infected mice showed enhanced sensitivity to D-amphetamine-induced (5 mg/kg i.p.) increase in locomotor activity as adults. Neonatally L-kynurenine treated mice showed enhanced sensitivity to D-amphetamine-induced (5 mg/kg i.p.) increase in locomotor activity as well as mild impairments in prepulse inhibition and memory. Also, D-amphetamine tended to potentiate dopamine release in the striatum in kynurenine-treated mice. These long-lasting behavioral and neurochemical alterations suggest that the kynurenine pathway can link early-life infection with the development of neuropsychiatric disturbances in adulthood.

Maternal Steroid Hormone Levels in Early Pregnancy and Autism in the Offspring: A Population-Based, Nested Case-Control Study.

BACKGROUND: A role for prenatal steroid hormones in the etiology of autism has been proposed, but evidence is conflicting. METHODS: Here, we examined serum levels of maternal estradiol, testosterone, 17-hydroxyprogesterone (OHP), and cortisol from the first trimester of gestation (mean = 10.1 weeks) in relation to the odds of diagnosed autism with and without co-occurring intellectual disability (ID) in the offspring (n = 118 autism with ID, n = 249 autism without ID, n = 477 control). Levels of maternal hormones were measured using highly sensitive liquid chromatography tandem mass spectrometry, standardized according to gestational timing of sample collection, and analyzed with restricted cubic spline logistic regression models adjusting for child's sex and maternal health, demographic, and socioeconomic factors. RESULTS: We observed significant nonlinear associations between maternal estradiol, 17-OHP, and cortisol with autism, which varied with the presence of co-occurring ID. Compared to mean levels, lower levels of estradiol were associated with higher odds of autism with ID (odds ratio for concentrations 1 SD below the mean = 1.66; 95% CI, 1.24-2.11), while higher cortisol levels were associated with lower odds (odds ratio for 1 SD above the mean = 0.55; 95% CI, 0.36-0.88). In contrast, higher 17-OHP was associated with increased odds of autism without ID (odds ratio for 1 SD above the mean = 1.49; 95% CI, 1.11-1.99). We observed no evidence for interaction with sex of the child. CONCLUSIONS: These findings support the notion that the maternal steroid hormonal environment in early pregnancy may contribute to autism, but also emphasize the complex relationship between early-life steroid exposure and autism.

Suppression of 5'-nucleotidase enzymes promotes AMP-activated protein kinase (AMPK) phosphorylation and metabolism in human and mouse skeletal muscle.

The 5'-nucleotidase (NT5) family of enzyme dephosphorylates non-cyclic nucleoside monophosphates to produce nucleosides and inorganic phosphates. We hypothesized that gene silencing of NT5 enzymes to increase the intracellular availability of AMP would increase AMP-activated protein kinase (AMPK) activity and metabolism. We determined the role of cytosolic NT5 in metabolic responses linked to the development of insulin resistance in obesity and type 2 diabetes. Using siRNA to silence NT5C2 expression in cultured human myotubes, we observed a 2-fold increase in the AMP/ATP ratio, a 2.4-fold increase in AMPK phosphorylation (Thr(172)), and a 2.8-fold increase in acetyl-CoA carboxylase phosphorylation (Ser(79)) (p < 0.05). siRNA silencing of NT5C2 expression increased palmitate oxidation by 2-fold in the absence and by 8-fold in the presence of 5-aminoimidazole-4-carboxamide 1-ß-d-ribofuranoside. This was paralleled by an increase in glucose transport and a decrease in glucose oxidation, incorporation into glycogen, and lactate release from NT5C2-depleted myotubes. Gene silencing of NT5C1A by shRNA injection and electroporation in mouse tibialis anterior muscle reduced protein content (60%; p < 0.05) and increased phosphorylation of AMPK (60%; p < 0.05) and acetyl-CoA carboxylase (50%; p < 0.05) and glucose uptake (20%; p < 0.05). Endogenous expression of NT5C enzymes inhibited basal lipid oxidation and glucose transport in skeletal muscle. Reduction of 5'-nucleotidase expression or activity may promote metabolic flexibility in type 2 diabetes.

Childhood infections and autism spectrum disorders and/or intellectual disability: a register-based cohort study.

OBJECTIVE: To explore the associations between childhood infections and subsequent diagnoses of autism spectrum disorder (ASD), intellectual disability (ID), and their co-occurrence. METHODS: The association between specialized care for any infection, defined by ICD-codes, and later ASD or ID was investigated in a register-based cohort of 556,732 individuals born 1987-2010, resident in Stockholm County, followed from birth to their 18th birthday or December 31, 2016. We considered as potential confounders children's characteristics, family socioeconomic factors, obstetric complications, and parental histories of treatment for infection and psychiatric disorders in survival analyses with extended Cox regression models. Residual confounding by shared familial factors was addressed in sibling analyses using within-strata estimation in Cox regression models. Sensitivity analyses with the exclusion of congenital causes of ASD/ID and documented risk for infections were also performed. RESULTS: Crude estimates indicated that infections during childhood were associated with later ASD and ID with the largest risks observed for diagnoses involving ID. Inclusion of covariates, exclusion of congenital causes of ASD/ID from the population, and sibling comparisons highlighted the potential for confounding by both heritable and non-heritable factors, though risks remained in all adjusted models. In adjusted sibling comparisons, excluding congenital causes, infections were associated with later "ASD without ID" (HR 1.24, 95%CI 1.15-1.33), "ASD with ID" (1.57, 1.35-1.82), and "ID without ASD" (2.01, 1.76-2.28). Risks associated with infections varied by age at exposure and by age at diagnosis of ASD/ID. CONCLUSIONS: Infections during childhood may contribute to a later diagnosis of ID and ASD.

Maternal levels of acute phase proteins in early pregnancy and risk of autism spectrum disorders in offspring.

Previous research supports a contribution of early-life immune disturbances in the etiology of autism spectrum disorders (ASD). Biomarker studies of the maternal innate (non-adaptive) immune status related to ASD risk have focused on one of the acute phase proteins (APP), C-reactive protein (CRP), with conflicting results. We evaluated levels of eight different APP in first-trimester maternal serum samples, from 318 mothers to ASD cases and 429 mothers to ASD-unaffected controls, nested within the register-based Stockholm Youth Cohort. While no overall associations between high levels of APP and ASD were observed, associations varied across diagnostic sub-groups based on co-occurring conditions. Maternal levels of CRP in the lowest compared to the middle tertile were associated with increased risk of ASD without ID or ADHD in offspring (OR = 1.92, 95% CI 1.08-3.42). Further, levels of maternal ferritin in the lowest (OR = 1.78, 95% CI 1.18-2.69) and highest (OR = 1.64, 95% CI 1.11-2.43) tertiles were associated with increased risk of any ASD diagnosis in offspring, with stronger associations still between the lowest (OR = 3.81, 95% CI 1.91-7.58) and highest (OR = 3.36, 95% CI 1.73-6.53) tertiles of ferritin and risk of ASD with ID. The biological interpretation of lower CRP levels among mothers to ASD cases is not clear but might be related to the function of the maternal innate immune system. The finding of aberrant levels of ferritin conferring risk of ASD-phenotypes indicates a plausibly important role of iron during neurodevelopment.