Background Schizophrenia is a severe neuropsychiatric disorder characterized by episodic psychosis and cognitive impairment. Large-scale GWAS and exome sequencing have enabled systematic discovery of schizophrenia risk variants. There is growing evidence to support a role of epigenetic variation in the etiology of schizophrenia. To date, however, epigenetic studies of schizophrenia have profiled only blood or bulk cortex tissue masking cell-type-specific signals. Our study represents the most comprehensive study of DNA methylation yet undertaken, profiling neuron-, oligodendrocyte-, and microglia-enriched nuclei populations isolated from the prefrontal cortex from 197 post-mortem donors enabling the first systematic cell-type-specific epigenome-wide association study (EWAS) of schizophrenia. Methods Using a novel fluorescence-activated nuclei sorting (FANS) protocol we isolated neuronal, oligodendrocyte, and microglial nuclei populations from post-mortem PFC tissue dissected from 197 donors (96 schizophrenia cases, 101 non-psychiatric controls). DNA methylation was assessed genome-wide using the Illumina EPIC array, alongside parallel profiling of bulk PFC tissue. Following rigorous quality control, we performed cell-type-specific EWAS to identify differentially methylated positions (DMPs) and regions (DMRs) associated with schizophrenia. Selected findings were validated via bisulfite pyrosequencing and integrated with matched ATAC-seq and long-read transcriptome data from the same samples. Results We identified 16 DMPs in PFC neurons that reached experiment-wide significance (P < 9 × 10⁻⁸) with 428 additional DMPs identified at P < 1 × 10⁻⁴. Notably, no significant methylation differences were detected in bulk PFC, oligodendrocytes, or microglia. Neuronal DMPs were strongly enriched for sites being hypomethylated in schizophrenia, with genes annotated to these sites being enriched for loci identified in genetic studies of schizophrenia including CACNA1C and TRIO. Discussion Our findings provide robust evidence for neuron-specific DNA methylation alterations in the PFC in schizophrenia. These results underscore the value of cell-type-specific epigenomic profiling, which reveals regulatory changes obscured in bulk tissue analyses. Our results support the notion that neuron-specific gene network dysregulation is central to the pathogenesis of schizophrenia.

There is mounting evidence to support a role for developmentally regulated epigenetic variation in the molecular etiology of schizophrenia. Previous analyses of epigenetic variation in the human brain have been limited to the study of bulk tissue, which is a heterogeneous mix of different cell types. We sought to characterize cell-type-specific epigenetic signatures across human cortex development and relate this to differences identified in schizophrenia. To obtain purified populations of neural cell types from post-mortem prefrontal cortex tissue, we used fluorescence-activated nuclei sorting (FANS) to gate and select NeuN+/SATB2+ (neuronal), SOX10+ (oligodendrocytes) and IRF8+ (microglial) immunolabeled nuclei populations derived from prefrontal cortex tissue from 150 schizophrenia cases and 150 controls, profiling DNA methylation using the Illumina EPIC BeadArray. In parallel we characterized cell-type-specific DNA methylation profiles in 150 fetal cortex samples spanning 6 weeks post-conception (wpc) to 23 wpc. After processing these data though a standardised quality control pipeline, that validates cell identity, we performed a cell-type-specific association analysis of schizophrenia status using a mixed effect models. We identified > 100 positions across the genome with significant epigenetic differences associated with schizophrenia. Many of these associations were specific to a single cell type, although some were associated with consistent differences across all neural cell types tested. We identified dramatic cell-type-specific shifts in DNA methylation across human cortex development, with enrichment of neurodevelopmentally-dynamic sites amongst genomic regions implicated in schizophrenia. Our data support the hypothesis that schizophrenia has an important early neurodevelopmental component, and confirm that epigenetic mechanisms may mediate these effects. Our results advance previous epigenetic analyses of schizophrenia by determining the relevant neural cell-type underlying epigenetic dysregulation in disease.

To determine the prevalence of Chlamydia trachomatis (CT) in the population screened at sexually transmitted infection (STI) clinics on Reunion Island and to identify risk factors for CT infection.This cross-sectional multicenter study was conducted in 2017–2018. Data were obtained from self-administered questionnaires and multiplex PCR tests.The overall prevalence of CT in the screened population was 8.6% (95% CI 7.7–9.5%). The prevalence of urogenital CT was highest in women under 18 (13.2%, 95% CI 9.3–18.1%) and in men who have sex with men under 18 (13.3%, 95% CI 1.6–48.2%). Risk factors associated with CT infection in multivariate analysis were: female gender, being born in Reunion Island, having had a large number of sexual partners in the past year, and being co-infected with another STI.The prevalence of CT in the screened population is higher in Reunion Island than in mainland France, especially in minors. Prevention campaigns targeting minors should be strengthened.

The increasing demand for electricity over the past few decades has been continuously urging for more reliable power systems. Power transmission line networks, due to their vast physical dimensions, are the most critical components of a complex power system concerning the direct lightning strike. Grounding systems are widely used to mitigate the transient overvoltages for the protection of electrical component and human safety. The goal of this paper is to investigate the effect of frequency dependence of soil electrical parameters on the performance of vertical and horizontal grounding electrodes subjected to direct lightning strike, considering a variable water content of soil. Four soil models that take into account the variation of soil water content are reviewed and compared. The numerical simulations are performed using a full-wave electromagnetic model based on the Finite Element Method (FEM) in the frequency range from 1 kHz to 5 MHz and applying different soil models with varying water content. Then, electromagnetic transient (EMT) compatible equivalent circuits of grounding electrodes are developed using Fast Relaxed Vector Fitting (FRVF). Typical first and subsequent return stroke current waveforms measured at two different locations are adopted. The results of this paper demonstrate the importance of considering the variation of soil water content in the transient response of grounding electrodes. Simulation results demonstrate that the frequency dependence of the soil parameters lead to a decrease of the potential rise of the grounding electrodes compared to the case where the soil parameters are assumed constant. The effect of soil water content on the grounding performance is also shown to be dependent on the soil type, value of soil water content, and length of electrode.

Eukaryotic translation initiation factor 1A (eIF1A) functions as an important regulatory factor of protein synthesis and plays a crucial role in responses to abiotic stresses in plants. However, little is known about the eIF1A gene involved in fruit development and stress response of mango. In this study, the MieIF1A-b gene was isolated from Mangifera indica, and contains a 435-bp open reading frame, which encodes a putative protein of 144 amino acids (GenBank accession number: KP676599). The predicted MieIF1A-b protein had a molecular weight of 16.39 kDa with a pI of 4.6. Sequence homology analysis showed that MieIF1A-b shared high homology with Elaeis guineensis, Manihot esculenta, and Populus trichocarpa, with 96 and 95% identity, respectively. Quantitative reverse transcriptative PCR (qRT-PCR) analyses indicated that MieIF1A-b was expressed in all tested tissues, and had the highest expression level in fruit 80 d after flowering. The expression of MieIF1A-b was obviously regulated by NaCl and H2O2 treatments in leaves. Functional analysis indicated that the overexpression of MieIF1A-b in transgenic Arabidopsis thaliana enhanced the growth, phenotype and salinity tolerance compared with wild-type (WT) plants. The results indicated that MieIF1A-b may be correlated with the control of fruit development and salt adaptation, and it was a candidate gene for abiotic stress in mango.

Success in the identification of genetic variants associated with neuropsychiatric disorders is one of the major achievements in contemporary biomedical research. Most genetic variants identified in Genome-Wide Association Studies (GWAS) of complex traits are thought to act via effects on gene regulation rather than directly altering the protein product. As a consequence, the actual genes involved in disease are not necessarily the most proximal to the associated variants. By integrating data from GWAS analyses with that from genetic studies of regulatory variation, it is possible to identify variants pleiotropically-associated with both a complex trait and measures of gene regulation. In this study, we use Summary data–based Mendelian Randomization (SMR), a method developed to identify variants pleiotropically associated with both complex traits and gene expression, to identify associations between neuropsychiatric disorders and DNA methylation. Building on our previous efforts, we increased our catalogue of DNA Methylation Quantitative Trait Loci (mQTL) in whole blood using the Illumina EPIC HumanMethylation array that interrogates over 800,000 genomic loci. These data along with mQTL data identified previously in human fetal brain were used to prioritize genes for psychiatric disorders using GWAS data from the Psychiatric Genomics Consortium (PGC). In this study, we apply the SMR approach to test 129,469 DNA methylation sites against five psychiatric phenotypes (schizophrenia, bipolar disorder, major depressive disorder, autism, ADHD) with robust GWAS data available from the PGC using mQTLs identified in whole blood (n=1,175; mQTL P < 1×10-10) to identify novel associations with psychiatric traits. In addition, we tested 9,261 DNA methylation sites using mQTL identified in fetal brain (n=166; mQTL P < 1×10-8). In total, we identified 107 associations with 37 satisfied addition criteria to be defined as pleiotropic and not an artefact of linkage disequilibrium. We identify multiple examples of variable DNA methylation associated with GWAS variants across the five psychiatric disorders, demonstrating the utility of the SMR approach for refining genetic association signals.

Epigenetic processes play a key role in orchestrating transcriptional regulation during the development of the human central nervous system. We have quantified dynamic changes in DNA methylation (5mC) and DNA hydroxymethylation (5hmC) occurring during human fetal brain development, using a unique collection of human fetal brain samples spanning 23 to 184 days post-conception. We identify widespread changes in both modifications occurring during human brain development, notable sex-differences, and interactions between 5mC and 5hmC at specific sites. We also identify loci where DNA modifications in the fetal brain are associated with genetic variation, highlighting the utility of mQTLs and hmQTLs for fine-mapping GWAS loci of neurodevelopmental phenotypes. Finally, we have examined variation in both 5mC and 5hmC across multiple regions of the adult brain in neurodevelopmental phenotypes including schizophrenia and autism, identifying disease-associated DNA modifications and relating these to neurodevelopmental trajectories of gene regulation. A searchable database of our fetal brain regulatory genomic data is available as a resource to the research community at http://epigenetics.essex.ac.uk/fetalbrain2/.

Accelerated DNA methylation age is linked to all-cause mortality and environmental factors, but studies of associations with socioeconomic position are limited. Researchers generally use small selected samples, and it is unclear how findings obtained with 2 commonly used methods for calculating methylation age (the Horvath method and the Hannum method) translate to general population samples including younger and older adults. Among 1,099 United Kingdom adults aged 28-98 years in 2011-2012, we assessed the relationship of Horvath and Hannum DNA methylation age acceleration with a range of social position measures: current income and employment, education, income and unemployment across a 12-year period, and childhood social class. Accounting for confounders, participants who had been less advantaged in childhood were epigenetically "older" as adults: In comparison with participants who had professional/managerial parents, Hannum age was 1.07 years higher (95% confidence interval: 0.20, 1.94) for participants with parents in semiskilled/unskilled occupations and 1.85 years higher (95% confidence interval: 0.67, 3.02) for those without a working parent at age 14 years. No other robust associations were seen. Results accord with research implicating early life circumstances as critical for DNA methylation age in adulthood. Since methylation age acceleration as measured by the Horvath and Hannum estimators appears strongly linked to chronological age, researchers examining associations with the social environment must take steps to avoid age-related confounding.

s of the XXV World Congress of Psychiatric Genetics (WCPG): Oral Abstracts Saturday, October 14, 2017 Saturday Afternoon Oral Session: Schizophrenia 1:30 p.m. 3:00 p.m. 1. USING GENETIC DIVERSITY FROM EAST ASIA TO IMPROVE THE BIOLOGICAL INSIGHT INTO SCHIZOPHRENIA Hailiang Huang, Max Lam n, Chia-Yen Chen, Alicia Martin, Zhiqiang Li, Stephan Ripke, Michael O'Donovan, Mark Daly, Psychiatric Genomics Consortium Institute of Mental Health Massachusetts General Hospital Bio-X Institute Cardiff University Analytic and Translational Genetics Unit Asian Schizophrenia Working Group Background: Schizophrenia is a chronic and disabling psychiatric disorder affecting about 1% of the world population. While the biological mechanisms of schizophrenia remain largely elusive, much progress has been made in schizophrenia genetics in the past few years, with over 100 genomic loci associated with schizophrenia reported by the recent large-scale genome-wide association study. However, to date, almost all large schizophrenia genetics studies are derived from primarily European descent population, severely limiting our understanding of schizophrenia biology. Methods: Here we present a large-scale schizophrenia genetic study, comprising of 12 schizophrenia case-control cohorts from Singapore, Hong Kong, Taiwan, mainland China, Japan, and Indonesia. After quality control, there are 13,760 cases and 16,883 controls available for genome-wide association. A fixed effect meta-analysis across Asian and Caucasian populations was conducted resulting in a combined sample of 46,945 cases and 59,800 controls. A novel finemapping algorithm was designed and conducted to identify potential causal variants between Caucasian and Asian samples. Results: Twelve loci (po5e-8) were found associated with schizophrenia in the Asian sample. Six were previously associated with schizophrenia, and four are novel. An example is a new locus (Caucasians 0.7%; Asians 45%), which may have been previously missed, implicates CACNA2D2, a calcium channel auxiliary subunit associated with early infantile epileptic encephalopathy. Meta-analysis across Asian and Caucasian populations identified 40 new loci implicated in schizophrenia. Genetic effects are consistent in both populations. Using a published fine-mapping method and a European-only dataset, we mapped 11 schizophrenia associations to a credible set of r5 variants. The number increased to 18 associations when we used the novel finemapping algorithm on a combined European and Asian dataset, demonstrating a significantly improved association resolution. Discussion: The reported results consist of amongst the largest collection of Asian GWAS samples to date. Evidence indicates shared biology across major world populations in schizophrenia. Specifically, across the two populations, all known schizophrenia associations were congruent in effect directions, and effect sizes show no significant heterogeneity. Our approach not only serve to improve detection of common variant loci that implicates two major populations in the world, the approach we have undertaken, improved GWA resolution which in turn allows us to better isolate the causal alleles and facilitate the functional interpretation of schizophrenia associations. Disclosure: Nothing to disclose. http://dx.doi.org/10.1016/j.euroneuro.2017.08.002

Large samples and systematic screens of thousands of DNA markers are needed to detect quantitative trait loci (QTLs) of small effect size. One approach to conduct systematic genome scans for association is to use microarrays which, although expensive and non-reusable, simultaneously genotype thousands of single-nucleotide polymorphisms (SNPs). This brief report provides proof of principle that groups of pooled DNA (for example cases and controls) can be genotyped reliably on a microarray. DNA was pooled for 105 Caucasian males and genotyped three times on microarrays for more than 10,000 SNPs (Affymetrix GeneChip® Mapping 10K Array Xba 131). The average correlation was 0.973 between the allele frequency estimates for the three microarrays using the same DNA pool. The correlation was 0.923 between the average of the three microarray estimates using pooled DNA and individual genotyping estimates for a Caucasian population as provided by Affymetrix (NetAffxTM). Thus, genotyping pooled DNA on microarrays can provide a systematic and powerful approach for identifying QTL associations for complex traits including behavioral dimensions and disorders.