38 research outputs found
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The ASD Living Biology: from cell proliferation to clinical phenotype.
Autism spectrum disorder (ASD) has captured the attention of scientists, clinicians and the lay public because of its uncertain origins and striking and unexplained clinical heterogeneity. Here we review genetic, genomic, cellular, postmortem, animal model, and cell model evidence that shows ASD begins in the womb. This evidence leads to a new theory that ASD is a multistage, progressive disorder of brain development, spanning nearly all of prenatal life. ASD can begin as early as the 1st and 2nd trimester with disruption of cell proliferation and differentiation. It continues with disruption of neural migration, laminar disorganization, altered neuron maturation and neurite outgrowth, disruption of synaptogenesis and reduced neural network functioning. Among the most commonly reported high-confidence ASD (hcASD) genes, 94% express during prenatal life and affect these fetal processes in neocortex, amygdala, hippocampus, striatum and cerebellum. A majority of hcASD genes are pleiotropic, and affect proliferation/differentiation and/or synapse development. Proliferation and subsequent fetal stages can also be disrupted by maternal immune activation in the 1st trimester. Commonly implicated pathways, PI3K/AKT and RAS/ERK, are also pleiotropic and affect multiple fetal processes from proliferation through synapse and neural functional development. In different ASD individuals, variation in how and when these pleiotropic pathways are dysregulated, will lead to different, even opposing effects, producing prenatal as well as later neural and clinical heterogeneity. Thus, the pathogenesis of ASD is not set at one point in time and does not reside in one process, but rather is a cascade of prenatal pathogenic processes in the vast majority of ASD toddlers. Despite this new knowledge and theory that ASD biology begins in the womb, current research methods have not provided individualized information: What are the fetal processes and early-age molecular and cellular differences that underlie ASD in each individual child? Without such individualized knowledge, rapid advances in biological-based diagnostic, prognostic, and precision medicine treatments cannot occur. Missing, therefore, is what we call ASD Living Biology. This is a conceptual and paradigm shift towards a focus on the abnormal prenatal processes underlying ASD within each living individual. The concept emphasizes the specific need for foundational knowledge of a living child's development from abnormal prenatal beginnings to early clinical stages. The ASD Living Biology paradigm seeks this knowledge by linking genetic and in vitro prenatal molecular, cellular and neural measurements with in vivo post-natal molecular, neural and clinical presentation and progression in each ASD child. We review the first such study, which confirms the multistage fetal nature of ASD and provides the first in vitro fetal-stage explanation for in vivo early brain overgrowth. Within-child ASD Living Biology is a novel research concept we coin here that advocates the integration of in vitro prenatal and in vivo early post-natal information to generate individualized and group-level explanations, clinically useful prognoses, and precision medicine approaches that are truly beneficial for the individual infant and toddler with ASD
Atypical genomic cortical patterning in autism with poor early language outcome.
Cortical regionalization develops via genomic patterning along anterior-posterior (A-P) and dorsal-ventral (D-V) gradients. Here, we find that normative A-P and D-V genomic patterning of cortical surface area (SA) and thickness (CT), present in typically developing and autistic toddlers with good early language outcome, is absent in autistic toddlers with poor early language outcome. Autistic toddlers with poor early language outcome are instead specifically characterized by a secondary and independent genomic patterning effect on CT. Genes involved in these effects can be traced back to midgestational A-P and D-V gene expression gradients and different prenatal cell types (e.g., progenitor cells and excitatory neurons), are functionally important for vocal learning and human-specific evolution, and are prominent in prenatal coexpression networks enriched for high-penetrance autism risk genes. Autism with poor early language outcome may be explained by atypical genomic cortical patterning starting in prenatal development, which may detrimentally affect later regional functional specialization and circuit formation
Pre-treatment clinical and gene expression patterns predict developmental change in early intervention in autism.
Funder: U.S. Department of Health & Human Services | NIH | National Institute of Mental Health (NIMH)Early detection and intervention are believed to be key to facilitating better outcomes in children with autism, yet the impact of age at treatment start on the outcome is poorly understood. While clinical traits such as language ability have been shown to predict treatment outcome, whether or not and how information at the genomic level can predict treatment outcome is unknown. Leveraging a cohort of toddlers with autism who all received the same standardized intervention at a very young age and provided a blood sample, here we find that very early treatment engagement (i.e., <24 months) leads to greater gains while controlling for time in treatment. Pre-treatment clinical behavioral measures predict 21% of the variance in the rate of skill growth during early intervention. Pre-treatment blood leukocyte gene expression patterns also predict the rate of skill growth, accounting for 13% of the variance in treatment slopes. Results indicated that 295 genes can be prioritized as driving this effect. These treatment-relevant genes highly interact at the protein level, are enriched for differentially histone acetylated genes in autism postmortem cortical tissue, and are normatively highly expressed in a variety of subcortical and cortical areas important for social communication and language development. This work suggests that pre-treatment biological and clinical behavioral characteristics are important for predicting developmental change in the context of early intervention and that individualized pre-treatment biology related to histone acetylation may be key
Large-scale associations between the leukocyte transcriptome and BOLD responses to speech differ in autism early language outcome subtypes.
Heterogeneity in early language development in autism spectrum disorder (ASD) is clinically important and may reflect neurobiologically distinct subtypes. Here, we identified a large-scale association between multiple coordinated blood leukocyte gene coexpression modules and the multivariate functional neuroimaging (fMRI) response to speech. Gene coexpression modules associated with the multivariate fMRI response to speech were different for all pairwise comparisons between typically developing toddlers and toddlers with ASD and poor versus good early language outcome. Associated coexpression modules were enriched in genes that are broadly expressed in the brain and many other tissues. These coexpression modules were also enriched in ASD-associated, prenatal, human-specific, and language-relevant genes. This work highlights distinctive neurobiology in ASD subtypes with different early language outcomes that is present well before such outcomes are known. Associations between neuroimaging measures and gene expression levels in blood leukocytes may offer a unique in vivo window into identifying brain-relevant molecular mechanisms in ASD
Guidance notes for Health Authorities and NHS Trusts on requirements for films, screens and cassettes used in breast screening mammography
Prepared by the King's Centre for Assessment of Radiological Equipment (KCARE)SIGLEGBUnited Kingdo
Motif enrichment analysis using available transcriptome and proteome data of <i>T</i>. <i>brucei</i>.
<p>For each GRAFFER motif, transcripts containing the motif in their 3′-UTR were selected and then tested for a statistically significant pattern in each cell state using standard Mann-Whitney rank sum statistic. (a) Developmental transcriptome responses of the eleven GRAFFER motifs that matched with the previously known RREs in <i>T</i>. <i>brucei</i>. For illustrative purposes, the full transcriptome enrichment analysis for the rest of the predicted motifs is not represented here. The complete results of this analysis are illustrated in S8 and S9 Figs. (b) Proteome enrichment analysis revealed that 19 motifs showed significant enrichment under at least one condition. The outer layer of circle indicates the motif id, excluding “GBM_TB” term due to illustration limitations. The intermediate circular layers indicate the up- or down-regulation of the motifs in a specific condition. The inner circular layer represents the consensus patterns of motifs. The center of circle shows the conditions that were tested for the enrichment with the reference for the study that data was extracted from.</p
Developmentally regulated U-rich RRE in <i>T</i>. <i>brucei</i>.
<p>Comparison of an experimentally established RRE (UAUUUUUU) that is involved in developmental regulation of <i>T</i>. <i>brucei</i> genes, with GRAFFER motif, GBM_TB_17304. (a) Venn-diagram of the transcripts that are targeted by UAUUUUUU and GBM_TB_17304 motifs. (b) Underlined regions show the U-rich regions (extracted from [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0142342#pone.0142342.ref035" target="_blank">35</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0142342#pone.0142342.ref036" target="_blank">36</a>]) with the experimentally-verified regulatory role that were used to infer UAUUUUUU regulatory element. The bold sequence in each U-rich region represents the part region that matches with GBM_TB_17304 motif.</p