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• Review of Hi-C genome-scale chromosome conformation ('3D Genome') mappings in brain. • Discussion of developmental 3DG reorganization in differentiating neurons. • Discussion of chromosomal contacts associated with schizophrenia risk sequences. • Monogenic neurological disorders and DNA repeats at chromatin domain boundaries. The 'non-linear' genome, or the spatial proximity of non-contiguous sequences, emerges as an important regulatory layer for genome organization and function, including transcriptional regulation. Here, we review recent genome-scale chromosome conformation mappings ('Hi-C') in developing and adult human and mouse brain. Neural differentiation is associated with widespread remodeling of the chromosomal contact map, reflecting dynamic changes in cell-type-specific gene expression programs, with a massive (estimated 20–50%) net loss of chromosomal contacts that is specific for the neuronal lineage. Hi-C datasets provided an unexpected link between locus-specific abnormal expansion of repeat sequences positioned at the boundaries of self-associating topological chromatin domains, and monogenic neurodevelopmental and neurodegenerative disease. Furthermore, integrative cell-type-specific Hi-C and transcriptomic analysis uncovered an expanded genomic risk space for sequences conferring liability for schizophrenia and other cognitive disease. We predict that spatial genome exploration will deliver radically new insights into the brain nucleome in health and disease. [ABSTRACT FROM AUTHOR]

Background: Trained medical interpreters are instrumental to patient satisfaction and quality of care. They are especially important in student-run clinics, where many patients have limited English proficiency. Because studentrun clinics have ties to their medical schools, they have access to bilingual students who may volunteer to interpret, but are not necessarily formally trained. Methods: To study the feasibility and efficacy of leveraging medical student volunteers to improve interpretation services, we performed a pilot study at the student-run clinic at the Icahn School of Medicine at Mount Sinai. In each fall semester in 2012-2015, we implemented a 6-h course providing didactic and interactive training on medical Spanish interpreting techniques and language skills to bilingual students. We then assessed the impact of the course on interpreter abilities. Results: Participants' comfort levels, understanding of their roles, and understanding of terminology significantly increased after the course (p < 0.05), and these gains remained several months later (p < 0.05) and were repeated in an independent cohort. Patients and student clinicians also rated participants highly (averages above 4.5 out of 5) on these measures in real clinical encounters. Conclusions: These findings suggest that a formal interpreter training course tailored for medical students in the setting of a student-run clinic is feasible and effective. This program for training qualified student interpreters can serve as a model for other settings where medical students serve as interpreters. [ABSTRACT FROM AUTHOR]

Cannabis remains one of the most widely abused drugs during pregnancy. In utero exposure to its principal psychoactive component, Δ9-tetrahydrocannabinol (THC), can result in long-term neuropsychiatric risk for the progeny. This study investigated epigenetic signatures underlying these enduring consequences. Rat dams were exposed daily to THC (0.15 mg/kg) during pregnancy, and adult male offspring were examined for reward and depressive-like behavioral endophenotypes. Using unbiased sequencing approaches, we explored transcriptional and epigenetic profiles in the nucleus accumbens (NAc), a brain area central to reward and emotional processing. An in vitro CRISPR (clustered regularly interspaced short palindromic repeats) activation model coupled with RNA sequencing was also applied to study specific consequences of epigenetic dysregulation, and altered molecular signatures were compared with human major depressive disorder transcriptome datasets. Prenatal THC exposure induced increased motivation for food, heightened learned helplessness and anhedonia, and altered stress sensitivity. We identified a robust increase specific to males in the expression of Kmt2a (histone-lysine N -methyltransferase 2A) that targets H3K4 (lysine 4 on histone H3) in cellular chromatin. Normalizing Kmt2a in the NAc rescued the motivational phenotype of prenatally THC-exposed animals. Comparison of RNA- and H3K4me3-sequencing datasets from the NAc of rat offspring with the in vitro model of Kmt2a upregulation revealed overlapping, significant disturbances in pathways that mediate synaptic plasticity. Similar transcriptional alterations were detected in human major depressive disorder. These studies provide direct evidence for the persistent effects of prenatal cannabis exposure on transcriptional and epigenetic deviations in the NAc via Kmt2a dysregulation and associated psychiatric vulnerability. [ABSTRACT FROM AUTHOR]

Background and Objectives: Immune checkpoint inhibitors (ICIs) are increasingly used against various cancers but are associated with immune-related adverse events (irAEs). Risk of irAEs may be higher in patients with certain preexisting autoimmune diseases, and these patients may also experience exacerbation of the underlying autoimmune disease following ICI initiation. People with multiple sclerosis (MS) have mostly been excluded from clinical trials of ICIs, so data on the safety of ICIs in MS are limited. This study aims to assess the rate of MS activity, as well as neurologic and nonneurologic irAEs in persons with MS treated with ICIs for cancer., Methods: Participating sites were invited to this retrospective observational study through the Medical Partnership 4 MS+ listserv. Seven large academic centers participated in the study, each conducting a systematic search of their electronic medical record system for patients with MS and history of ICI treatment. The participating neurologist reviewed each chart individually to ensure the inclusion criteria were met. Demographics and data on MS and cancer history, treatments, and outcomes were abstracted from patient charts using a structured instrument., Results: We identified 66 people with MS (median age 66 years, 73% female, 68% not on disease-modifying therapy for MS) who were treated with ICIs for lung cancer (35%), melanoma (21%), or another oncologic indication. During post-ICI follow-up (median: 11.7 months, range 0.2-106.3 months), 2 patients (3%) had relapse or MRI activity, 3 (5%) had neurologic irAEs, and 21 (32%) had nonneurologic irAEs. At the last follow-up, 25 (38%) participants had partial or complete remission of their cancer, while 35 (53%) were deceased., Discussion: In this multi-institutional systematic retrospective study of predominantly older patients with MS, most of whom were not on disease-modifying therapy, MS activity and neurologic irAEs following ICI treatment were rare. These data suggest that preexisting MS should not preclude the use of ICIs for cancer in older patients, but the results may not be generalizable to younger patients with active MS. Prospective studies of ICI safety that enroll younger patients with MS are needed.

While germline copy-number variants (CNVs) contribute to schizophrenia (SCZ) risk, the contribution of somatic CNVs (sCNVs)-present in some but not all cells-remains unknown. We identified sCNVs using blood-derived genotype arrays from 12,834 SCZ cases and 11,648 controls, filtering sCNVs at loci recurrently mutated in clonal blood disorders. Likely early-developmental sCNVs were more common in cases (0.91%) than controls (0.51%, p = 2.68e-4), with recurrent somatic deletions of exons 1-5 of the NRXN1 gene in five SCZ cases. Hi-C maps revealed ectopic, allele-specific loops forming between a potential cryptic promoter and non-coding cis -regulatory elements upon 5' deletions in NRXN1 . We also observed recurrent intragenic deletions of ABCB11 , encoding a transporter implicated in anti-psychotic response, in five treatment-resistant SCZ cases and showed that ABCB11 is specifically enriched in neurons forming mesocortical and mesolimbic dopaminergic projections. Our results indicate potential roles of sCNVs in SCZ risk., Competing Interests: The authors declare no competing interests., (© 2023 The Author(s).)

Schizophrenia is a debilitating psychiatric disorder with a complex genetic architecture and limited understanding of its neuropathology, reflected by the lack of diagnostic measures and effective pharmacological treatments. Geneticists have recently identified more than 145 risk loci comprising hundreds of common variants of small effect sizes, most of which lie in noncoding genomic regions. This review will discuss how the epigenetic toolbox can be applied to contextualize genetic findings in schizophrenia. Progress in next-generation sequencing, along with increasing methodological complexity, has led to the compilation of genome-wide maps of DNA methylation, histone modifications, RNA expression, and more. Integration of chromatin conformation datasets is one of the latest efforts in deciphering schizophrenia risk, allowing the identification of genes in contact with regulatory variants across 100s of kilobases. Large-scale multiomics studies will facilitate the prioritization of putative causal risk variants and gene networks that contribute to schizophrenia etiology, informing clinical diagnostics and treatment downstream.
., (© 2019, AICH Servier GroupCopyright © 2019 AICH Servier Group. All rights reserved.)

Chromosomal conformations, including promoter-enhancer loops, provide a critical regulatory layer for the transcriptional machinery. Therefore, schizophrenia, a common psychiatric disorder associated with broad changes in neuronal gene expression in prefrontal cortex and other brain regions implicated in psychosis, could be associated with alterations in higher-order chromatin. Here, we review early studies on spatial genome organization in the schizophrenia postmortem brain and discuss how integrative approaches using cell culture and animal model systems could gain deeper insight into the potential roles of higher-order chromatin for the neurobiology of and novel treatment avenues for common psychiatric disease., (Copyright © 2017. Published by Elsevier Inc.)

Modulation of transcription, either synthetic activation or repression, via dCas9-fusion proteins is a relatively new methodology with the potential to facilitate high-throughput up- or downregulation studies of gene function. Genetic studies of neurodevelopmental disorders have identified a growing list of risk variants, including both common single-nucleotide variants and rare copy-number variations, many of which are associated with genes having limited functional annotations. By applying a CRISPR-mediated gene-activation/repression platform to populations of human-induced pluripotent stem cell-derived neural progenitor cells, neurons, and astrocytes, we demonstrate that it is possible to manipulate endogenous expression levels of candidate neuropsychiatric risk genes across these three cell types. Although proof-of-concept studies using catalytically inactive Cas9-fusion proteins to modulate transcription have been reported, here we present a detailed survey of the reproducibility of gRNA positional effects across a variety of neurodevelopmental disorder-relevant risk genes, donors, neural cell types, and dCas9 effectors., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)

We report locus-specific disintegration of megabase-scale chromosomal conformations in brain after neuronal ablation of Setdb1 (also known as Kmt1e; encodes a histone H3 lysine 9 methyltransferase), including a large topologically associated 1.2-Mb domain conserved in humans and mice that encompasses >70 genes at the clustered protocadherin locus (hereafter referred to as cPcdh). The cPcdh topologically associated domain (TAD cPcdh ) in neurons from mutant mice showed abnormal accumulation of the transcriptional regulator and three-dimensional (3D) genome organizer CTCF at cryptic binding sites, in conjunction with DNA cytosine hypomethylation, histone hyperacetylation and upregulated expression. Genes encoding stochastically expressed protocadherins were transcribed by increased numbers of cortical neurons, indicating relaxation of single-cell constraint. SETDB1-dependent loop formations bypassed 0.2-1 Mb of linear genome and radiated from the TAD cPcdh fringes toward cis-regulatory sequences within the cPcdh locus, counterbalanced shorter-range facilitative promoter-enhancer contacts and carried loop-bound polymorphisms that were associated with genetic risk for schizophrenia. We show that the SETDB1 repressor complex, which involves multiple KRAB zinc finger proteins, shields neuronal genomes from excess CTCF binding and is critically required for structural maintenance of TAD cPcdh .