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1.
Proc Natl Acad Sci U S A ; 121(3): e2317668121, 2024 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-38194455

RESUMO

Orofacial clefts of the lip and palate are widely recognized to result from complex gene-environment interactions, but inadequate understanding of environmental risk factors has stymied development of prevention strategies. We interrogated the role of DNA methylation, an environmentally malleable epigenetic mechanism, in orofacial development. Expression of the key DNA methyltransferase enzyme DNMT1 was detected throughout palate morphogenesis in the epithelium and underlying cranial neural crest cell (cNCC) mesenchyme, a highly proliferative multipotent stem cell population that forms orofacial connective tissue. Genetic and pharmacologic manipulations of DNMT activity were then applied to define the tissue- and timing-dependent requirement of DNA methylation in orofacial development. cNCC-specific Dnmt1 inactivation targeting initial palate outgrowth resulted in OFCs, while later targeting during palatal shelf elevation and elongation did not. Conditional Dnmt1 deletion reduced cNCC proliferation and subsequent differentiation trajectory, resulting in attenuated outgrowth of the palatal shelves and altered development of cNCC-derived skeletal elements. Finally, we found that the cellular mechanisms of cleft pathogenesis observed in vivo can be recapitulated by pharmacologically reducing DNA methylation in multipotent cNCCs cultured in vitro. These findings demonstrate that DNA methylation is a crucial epigenetic regulator of cNCC biology, define a critical period of development in which its disruption directly causes OFCs, and provide opportunities to identify environmental influences that contribute to OFC risk.


Assuntos
Fenda Labial , Fissura Palatina , Animais , Camundongos , Fenda Labial/genética , Metilação de DNA , Fissura Palatina/genética , Crista Neural , Metilases de Modificação do DNA , Proliferação de Células
2.
Alzheimers Dement ; 20(2): 1050-1062, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37856321

RESUMO

INTRODUCTION: DNA microarray-based studies report differentially methylated positions (DMPs) in blood between late-onset dementia due to Alzheimer's disease (AD) and cognitively unimpaired individuals, but interrogate < 4% of the genome. METHODS: We used whole genome methylation sequencing (WGMS) to quantify DNA methylation levels at 25,409,826 CpG loci in 281 blood samples from 108 AD and 173 cognitively unimpaired individuals. RESULTS: WGMS identified 28,038 DMPs throughout the human methylome, including 2707 differentially methylated genes (e.g., SORCS3, GABA, and PICALM) encoding proteins in biological pathways relevant to AD such as synaptic membrane, cation channel complex, and glutamatergic synapse. One hundred seventy-three differentially methylated blood-specific enhancers interact with the promoters of 95 genes that are differentially expressed in blood from persons with and without AD. DISCUSSION: WGMS identifies differentially methylated CpGs in known and newly detected genes and enhancers in blood from persons with and without AD. HIGHLIGHTS: Whole genome DNA methylation levels were quantified in blood from persons with and without Alzheimer's disease (AD). Twenty-eight thousand thirty-eight differentially methylated positions (DMPs) were identified. Two thousand seven hundred seven genes comprise DMPs. Forty-eight of 75 independent genetic risk loci for AD have DMPs. One thousand five hundred sixty-eight blood-specific enhancers comprise DMPs, 173 of which interact with the promoters of 95 genes that are differentially expressed in blood from persons with and without AD.


Assuntos
Doença de Alzheimer , Metilação de DNA , Humanos , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Epigênese Genética , Sequenciamento Completo do Genoma
3.
Hum Mol Genet ; 32(24): 3312-3322, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37658766

RESUMO

Autism spectrum disorders (ASD) are polygenic multifactorial disorders influenced by environmental factors. ASD-related differential DNA methylation has been found in human peripheral tissues, such as placenta, paternal sperm, buccal epithelium, and blood. However, these data lack direct comparison of DNA methylation levels with brain tissue from the same individual to determine the extent that peripheral tissues are surrogates for behavior-related disorders. Here, whole genome methylation profiling at all the possible sites throughout the mouse genome (>25 million) from both brain and blood tissues revealed novel insights into the systemic contributions of DNA methylation to ASD. Sixty-six differentially methylated regions (DMRs) share the same genomic coordinates in these two tissues, many of which are linked to risk genes for neurodevelopmental disorders and intellectual disabilities (e.g. Prkch, Ptn, Hcfc1, Mid1, and Nfia). Gene ontological pathways revealed a significant number of common terms between brain and blood (N = 65 terms), and nearly half (30/65) were associated with brain/neuronal development. Furthermore, seven DMR-associated genes among these terms contain methyl-sensitive transcription factor sequence motifs within the DMRs of both tissues; four of them (Cux2, Kcnip2, Fgf13, and Mrtfa) contain the same methyl-sensitive transcription factor binding sequence motifs (HES1/2/5, TBX2 and TFAP2C), suggesting DNA methylation influences the binding of common transcription factors required for gene expression. Together, these findings suggest that peripheral blood is a good surrogate tissue for brain and support that DNA methylation contributes to altered gene regulation in the pathogenesis of ASD.


Assuntos
Transtorno Autístico , Metilação de DNA , Gravidez , Feminino , Masculino , Humanos , Animais , Camundongos , Metilação de DNA/genética , Transtorno Autístico/genética , Epigênese Genética , Sêmen , Fatores de Transcrição/genética , Hipocampo
4.
Am J Respir Cell Mol Biol ; 69(4): 383-390, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37379507

RESUMO

Over the last years, the use of peripheral blood-derived big datasets in combination with machine learning technology has accelerated the understanding, prediction, and management of pulmonary and critical care conditions. The goal of this article is to provide readers with an introduction to the methods and applications of blood omics and other multiplex-based technologies in the pulmonary and critical care medicine setting to better appreciate the current literature in the field. To accomplish that, we provide essential concepts needed to rationalize this approach and introduce readers to the types of molecules that can be obtained from the circulating blood to generate big datasets; elaborate on the differences between bulk, sorted, and single-cell approaches; and the basic analytical pipelines required for clinical interpretation. Examples of peripheral blood-derived big datasets used in recent literature are presented, and limitations of that technology are highlighted to qualify both the current and future value of these methodologies.


Assuntos
Cuidados Críticos , Aprendizado de Máquina , Humanos , Previsões
6.
Cancers (Basel) ; 15(4)2023 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-36831683

RESUMO

Gliomas, the most common type of malignant primary brain tumor, were conventionally classified through WHO Grades I-IV (now 1-4), with low-grade gliomas being entities belonging to Grades 1 or 2. While the focus of the WHO Classification for Central Nervous System (CNS) tumors had historically been on histopathological attributes, the recently released fifth edition of the classification (WHO CNS5) characterizes brain tumors, including gliomas, using an integration of histological and molecular features, including their epigenetic changes such as histone methylation, DNA methylation, and histone acetylation, which are increasingly being used for the classification of low-grade gliomas. This review describes the current understanding of the role of DNA methylation, demethylation, and histone modification in pathogenesis, clinical behavior, and outcomes of brain tumors, in particular of low-grade gliomas. The review also highlights potential diagnostic and/or therapeutic targets in associated cellular biomolecules, structures, and processes. Targeting of MGMT promoter methylation, TET-hTDG-BER pathway, association of G-CIMP with key gene mutations, PARP inhibition, IDH and 2-HG-associated processes, TERT mutation and ARL9-associated pathways, DNA Methyltransferase (DNMT) inhibition, Histone Deacetylase (HDAC) inhibition, BET inhibition, CpG site DNA methylation signatures, along with others, present exciting avenues for translational research. This review also summarizes the current clinical trial landscape associated with the therapeutic utility of epigenetics in low-grade gliomas. Much of the evidence currently remains restricted to preclinical studies, warranting further investigation to demonstrate true clinical utility.

7.
Environ Epigenet ; 9(1): dvad002, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36843857

RESUMO

Human epidemiological studies reveal that dietary and environmental alterations influence the health of the offspring and that the effect is not limited to the F1 or F2 generations. Non-Mendelian transgenerational inheritance of traits in response to environmental stimuli has been confirmed in non-mammalian organisms including plants and worms and are shown to be epigenetically mediated. However, transgenerational inheritance beyond the F2 generation remains controversial in mammals. Our lab previously discovered that the treatment of rodents (rats and mice) with folic acid significantly enhances the regeneration of injured axons following spinal cord injury in vivo and in vitro, and the effect is mediated by DNA methylation. The potential heritability of DNA methylation prompted us to investigate the following question: Is the enhanced axonal regeneration phenotype inherited transgenerationally without exposure to folic acid supplementation in the intervening generations? In the present review, we condense our findings showing that a beneficial trait (i.e., enhanced axonal regeneration after spinal cord injury) and accompanying molecular alterations (i.e., DNA methylation), triggered by an environmental exposure (i.e., folic acid supplementation) to F0 animals only, are inherited transgenerationally and beyond the F3 generation.

8.
Commun Biol ; 6(1): 120, 2023 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-36717618

RESUMO

While embryonic mammalian central nervous system (CNS) axons readily grow and differentiate, only a minority of fully differentiated mature CNS neurons are able to regenerate injured axons, leading to stunted functional recovery after injury and disease. To delineate DNA methylation changes specifically associated with axon regeneration, we used a Fluorescent-Activated Cell Sorting (FACS)-based methodology in a rat optic nerve transection model to segregate the injured retinal ganglion cells (RGCs) into regenerating and non-regenerating cell populations. Whole-genome DNA methylation profiling of these purified neurons revealed genes and pathways linked to mammalian RGC regeneration. Moreover, whole-methylome sequencing of purified uninjured adult and embryonic RGCs identified embryonic molecular profiles reactivated after injury in mature neurons, and others that correlate specifically with embryonic or adult axon growth, but not both. The results highlight the contribution to both embryonic growth and adult axon regeneration of subunits encoding the Na+/K+-ATPase. In turn, both biochemical and genetic inhibition of the Na+/K+-ATPase pump significantly reduced RGC axon regeneration. These data provide critical molecular insights into mammalian CNS axon regeneration, pinpoint the Na+/K+-ATPase as a key regulator of regeneration of injured mature CNS axons, and suggest that successful regeneration requires, in part, reactivation of embryonic signals.


Assuntos
Axônios , Metilação de DNA , Animais , Ratos , Adenosina Trifosfatases/metabolismo , Axônios/metabolismo , Regeneração Nervosa/genética , Células Ganglionares da Retina/fisiologia
9.
Sci Rep ; 12(1): 17177, 2022 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-36266402

RESUMO

Adverse childhood experiences (ACEs, i.e., abuse, neglect, household dysfunction) represent a potential risk factor for a wide range of long-lasting diseases and shorter life expectancy. We recently described a 1-week residential group program, based on mindfulness training, artistic expression and EMDR group therapy, that significantly reduced PTSD-related symptoms and increased attention/awareness-related outcomes in adolescent girls with multiple ACEs in a randomized controlled study. Since epigenetic mechanisms (i.e., DNA methylation) have been associated with the long-lasting effects of ACEs, the present report extends these prior findings by exploring genome-wide DNA methylation changes following the program. Saliva samples from all participants (n = 44) were collected and genomic DNA was extracted prior (T1) and following (T2) the intervention. Genome-wide DNA methylation analysis using the MethylationEPIC beadchip array (Illumina) revealed 49 differentially methylated loci (DML; p value < 0.001; methylation change > 10%) that were annotated to genes with roles in biological processes linked to early childhood adversity (i.e., neural, immune, and endocrine pathways, cancer and cardiovascular disease). DNA sequences flanking these DML showed significant enrichment of transcription factor binding sites involved in inflammation, cancer, cardiovascular disease, and brain development. Methylation changes in SIRT5 and TRAPPC2L genes showed associations with changes in trauma-related psychological measures. Results presented here suggest that this multimodal group program for adolescents with multiple victimization modulates the DNA methylome at sites of potential relevance for health and behavioral disorders associated with ACEs.


Assuntos
Experiências Adversas da Infância , Epigênese Genética , Adolescente , Feminino , Humanos , Doenças Cardiovasculares/genética , Metilação de DNA , Fatores de Transcrição/genética , Inflamação/genética , Neoplasias/genética
10.
Clin Epigenetics ; 14(1): 94, 2022 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-35871090

RESUMO

We recently reported the COVID-19-induced circulating leukocytes DNA methylation profile. Here, we hypothesized that some of these genes would persist differentially methylated after disease resolution. Fifteen participants previously hospitalized for SARS-CoV-2 infection were epityped one year after discharge. Of the 1505 acute illness-induced differentially methylated regions (DMRs) previously identified, we found 71 regions with persisted differentially methylated, with an average of 7 serial CpG positions per DMR. Sixty-four DMRs persisted hypermethylated, and 7 DMR persisted hypomethylated. These data are the first reported evidence that DNA methylation changes in circulating leukocytes endure long after recovery from acute illness.


Assuntos
COVID-19 , Metilação de DNA , Doença Aguda , COVID-19/genética , Ilhas de CpG , Humanos , SARS-CoV-2
11.
Genome Res ; 32(2): 266-279, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34949667

RESUMO

Mouse knockouts of Cntnap2 show altered neurodevelopmental behavior, deficits in striatal GABAergic signaling, and a genome-wide disruption of an environmentally sensitive DNA methylation modification (5-hydroxymethylcytosine [5hmC]) in the orthologs of a significant number of genes implicated in human neurodevelopmental disorders. We tested adult Cntnap2 heterozygous mice (Cntnap2 +/-; lacking behavioral or neuropathological abnormalities) subjected to a prenatal stress and found that prenatally stressed Cntnap2 +/- female mice show repetitive behaviors and altered sociability, similar to the homozygote phenotype. Genomic profiling revealed disruptions in hippocampal and striatal 5hmC levels that are correlated to altered transcript levels of genes linked to these phenotypes (e.g., Reln, Dst, Trio, and Epha5). Chromatin immunoprecipitation coupled with high-throughput sequencing and hippocampal nuclear lysate pull-down data indicated that 5hmC abundance alters the binding of the transcription factor CLOCK near the promoters of these genes (e.g., Palld, Gigyf1, and Fry), providing a mechanistic role for 5hmC in gene regulation. Together, these data support gene-by-environment hypotheses for the origins of mental illness and provide a means to identify the elusive factors contributing to complex human diseases.


Assuntos
Interação Gene-Ambiente , Transtornos do Neurodesenvolvimento , 5-Metilcitosina/análogos & derivados , 5-Metilcitosina/metabolismo , Animais , Metilação de DNA , Epigênese Genética , Feminino , Proteínas de Membrana/metabolismo , Camundongos , Proteínas do Tecido Nervoso/metabolismo , Gravidez
12.
Sleep ; 44(10)2021 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-34145460

RESUMO

STUDY OBJECTIVES: Patients with unexplained hypersomnolence have significant impairment related to daytime sleepiness and excessive sleep duration, the biological bases of which are poorly understood. This investigation sought to examine relationships between objectively measured hypersomnolence phenotypes and epigenetic modification of candidate hypersomnolence genes to advance this line of inquiry. METHODS: Twenty-eight unmedicated clinical patients with unexplained hypersomnolence were evaluated using overnight ad libitum polysomnography, multiple sleep latency testing, infrared pupillometry, and the psychomotor vigilance task. DNA methylation levels on CpG sites annotated to 11 a priori hypersomnolence candidate genes were assessed for statistical association with hypersomnolence measures using independent regression models with adjusted local index of significance (aLIS) P-value threshold of 0.05. RESULTS: Nine CpG sites exhibited significant associations between DNA methylation levels and total sleep time measured using ad libitum polysomnography (aLIS p-value < .05). All nine differentially methylated CpG sites were annotated to the paired box 8 (PAX8) gene and its related antisense gene (PAX8-AS1). Among these nine differentially methylated positions was a cluster of five CpG sites located in the body of the PAX8 gene and promoter of PAX8-AS1. CONCLUSIONS: This study demonstrates that PAX8/PAX8-AS1 DNA methylation levels are associated with total sleep time in persons with unexplained hypersomnolence. Given prior investigations that have implicated single nucleotide polymorphisms in PAX8/PAX8-AS1 with habitual sleep duration, further research that clarifies the role of DNA methylation levels on these genes in the phenotypic expression of total sleep time is warranted.


Assuntos
Metilação de DNA , Distúrbios do Sono por Sonolência Excessiva/genética , Fator de Transcrição PAX8/genética , RNA Longo não Codificante/genética , Humanos , Polissonografia , Latência do Sono , Vigília
13.
Sci Rep ; 11(1): 12181, 2021 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-34108589

RESUMO

Maternal and environmental factors influence brain networks and architecture via both physiological pathways and epigenetic modifications. In particular, prenatal maternal depression and anxiety symptoms appear to impact infant white matter (WM) microstructure, leading us to investigate whether epigenetic modifications (i.e., DNA methylation) contribute to these WM differences. To determine if infants of women with depression and anxiety symptoms exhibit epigenetic modifications linked to neurodevelopmental changes, 52 umbilical cord bloods (CBs) were profiled. We observed 219 differentially methylated genomic positions (DMPs; FDR p < 0.05) in CB that were associated with magnetic resonance imaging measures of WM microstructure at 1 month of age and in regions previously described to be related to maternal depression and anxiety symptoms. Genomic characterization of these associated DMPs revealed 143 unique genes with significant relationships to processes involved in neurodevelopment, GTPase activity, or the canonical Wnt signaling pathway. Separate regression models for female (n = 24) and male (n = 28) infants found 142 associated DMPs in females and 116 associated DMPs in males (nominal p value < 0.001, R > 0.5), which were annotated to 98 and 81 genes, respectively. Together, these findings suggest that umbilical CB DNA methylation levels at birth are associated with 1-month WM microstructure.


Assuntos
Transtornos de Ansiedade/fisiopatologia , Encéfalo/patologia , Metilação de DNA , Transtorno Depressivo/fisiopatologia , Sangue Fetal/química , Efeitos Tardios da Exposição Pré-Natal/patologia , Substância Branca/patologia , Adolescente , Adulto , Encéfalo/metabolismo , Epigênese Genética , Feminino , Humanos , Recém-Nascido , Masculino , Gravidez , Efeitos Tardios da Exposição Pré-Natal/etiologia , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Substância Branca/metabolismo , Adulto Jovem
14.
Clin Epigenetics ; 13(1): 118, 2021 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-34034806

RESUMO

BACKGROUND: There are no prior reports that compare differentially methylated regions of DNA in blood samples from COVID-19 patients to samples collected before the SARS-CoV-2 pandemic using a shared epigenotyping platform. We performed a genome-wide analysis of circulating blood DNA CpG methylation using the Infinium Human MethylationEPIC BeadChip on 124 blood samples from hospitalized COVID-19-positive and COVID-19-negative patients and compared these data with previously reported data from 39 healthy individuals collected before the pandemic. Prospective outcome measures such as COVID-19-GRAM risk-score and mortality were combined with methylation data. RESULTS: Global mean methylation levels did not differ between COVID-19 patients and healthy pre-pandemic controls. About 75% of acute illness-associated differentially methylated regions were located near gene promoter regions and were hypo-methylated in comparison with healthy pre-pandemic controls. Gene ontology analyses revealed terms associated with the immune response to viral infections and leukocyte activation; and disease ontology analyses revealed a predominance of autoimmune disorders. Among COVID-19-positive patients, worse outcomes were associated with a prevailing hyper-methylated status. Recursive feature elimination identified 77 differentially methylated positions predictive of COVID-19 severity measured by the GRAM-risk score. CONCLUSION: Our data contribute to the awareness that DNA methylation may influence the expression of genes that regulate COVID-19 progression and represent a targetable process in that setting.


Assuntos
COVID-19/sangue , COVID-19/mortalidade , Metilação de DNA/fisiologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , New York/epidemiologia , Estudos Prospectivos , SARS-CoV-2
15.
Artigo em Inglês | MEDLINE | ID: mdl-33964519

RESUMO

BACKGROUND: Recent findings in neuroimaging and epigenetics offer important insights into brain structures and biological pathways of altered gene expression associated with posttraumatic stress disorder (PTSD). However, it is unknown to what extent epigenetic mechanisms are associated with PTSD and its neurobiology in youth. METHODS: In this study, we combined a methylome-wide association study and structural neuroimaging measures in a Dutch cohort of youths with PTSD (8-18 years of age). We aimed to replicate findings in a similar independent U.S. cohort. RESULTS: We found significant methylome-wide associations for pediatric PTSD (false discovery rate p < .05) compared with non-PTSD control groups (traumatized and nontraumatized youths). Methylation differences on nine genes were replicated, including genes related to glucocorticoid functioning. In both cohorts, methylation on OLFM3 gene was further associated with anterior hippocampal volume. CONCLUSIONS: These findings point to molecular pathways involved in inflammation, stress response, and neuroplasticity as potential contributors to neural abnormalities and provide potentially unique biomarkers and treatment targets for pediatric PTSD.


Assuntos
Transtornos de Estresse Pós-Traumáticos , Adolescente , Encéfalo , Criança , Metilação de DNA , Epigênese Genética , Hipocampo , Humanos , Transtornos de Estresse Pós-Traumáticos/genética
16.
Epigenetics ; 16(10): 1085-1101, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33172347

RESUMO

Maternal malnutrition remains one of the major adversities affecting brain development and long-term mental health outcomes, increasing the risk to develop anxiety and depressive disorders. We have previously shown that malnutrition-induced anxiety-like behaviours can be rescued by a social and sensory stimulation (enriched environment) in male mice. Here, we expand these findings to adult female mice and profiled genome-wide ventral hippocampal 5hmC levels related to malnutrition-induced anxiety-like behaviours and their rescue by an enriched environment. This approach revealed 508 differentially hydroxymethylated genes associated with protein malnutrition and that several genes (N = 34) exhibited a restored 5hmC abundance to control levels following exposure to an enriched environment, including genes involved in neuronal functions like dendrite outgrowth, axon guidance, and maintenance of neuronal circuits (e.g. Fltr3, Itsn1, Lman1, Lsamp, Nav, and Ror1) and epigenetic mechanisms (e.g. Hdac9 and Dicer1). Sequence motif predictions indicated that 5hmC may be modulating the binding of transcription factors for several of these transcripts, suggesting a regulatory role for 5hmC in response to perinatal malnutrition and exposure to an enriched environment. Together, these findings establish a role for 5hmC in early-life malnutrition and reveal genes linked to malnutrition-induced anxious behaviours that are mitigated by an enriched environment.


Assuntos
Metilação de DNA , Desnutrição , 5-Metilcitosina/análogos & derivados , Animais , Epigênese Genética , Feminino , Masculino , Camundongos
17.
Epigenetics ; 16(1): 64-78, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32633672

RESUMO

Alterations in environmentally sensitive epigenetic mechanisms (e.g., DNA methylation) influence axonal regeneration in the spinal cord following sharp injury. Conventional DNA methylation detection methods using sodium bisulphite treatment do not distinguish between methylated and hydroxymethylated forms of cytosine, meaning that past studies report a composite of 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC). To identify the distinct contributions of DNA methylation modifications to axonal regeneration, we collected spinal cord tissue after sharp injury from untreated adult F3 male rats with enhanced regeneration of injured spinal axons or controls, derived from folate- or water-treated F0 lineages, respectively. Genomic DNA was profiled for genome-wide 5hmC levels, revealing 658 differentially hydroxymethylated regions (DhMRs). Genomic profiling with whole genome bisulphite sequencing disclosed regeneration-related alterations in composite 5mC + 5hmC DNA methylation levels at 2,260 differentially methylated regions (DMRs). While pathway analyses revealed that differentially hydroxymethylated and methylated genes are linked to biologically relevant axon developmental pathways, only 22 genes harbour both DhMR and DMRs. Since these differential modifications were more than 60 kilobases on average away from each other, the large majority of differential hydroxymethylated and methylated regions are unique with distinct functions in the axonal regeneration phenotype. These data highlight the importance of distinguishing independent contributions of 5mC and 5hmC levels in the central nervous system, and denote discrete roles for DNA methylation modifications in spinal cord injury and regeneration in the context of transgenerational inheritance.


Assuntos
Axônios/metabolismo , Metilação de DNA , Regeneração Nervosa/genética , 5-Metilcitosina/análogos & derivados , 5-Metilcitosina/metabolismo , Animais , Epigênese Genética , Feminino , Masculino , Ratos , Ratos Sprague-Dawley , Transcriptoma
18.
Sci Rep ; 10(1): 10781, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32612155

RESUMO

Fragile X mental retardation protein (FMRP) binds to and regulates the translation of amyloid-ß protein precursor (App) mRNA, but the detailed mechanism remains to be determined. Differential methylation of App mRNA could underlie FMRP binding, message localization and translation efficiency. We sought to determine the role of FMRP and N6-methyladeonsine (m6A) on nuclear export of App mRNA. We utilized the m6A dataset by Hsu and colleagues to identify m6A sites in App mRNA and to determine if the abundance of message in the cytoplasm relative to the nucleus is altered in Fmr1 knockout mouse brain cortex. Given that processing of APP to Aß and soluble APP alpha (sAPPα) contributes to disease phenotypes, we also investigated whether Fmr1KO associates with nuclear export of the mRNAs for APP protein processing enzymes, including ß-site amyloid cleaving enzyme (Bace1), A disintegrin and metalloproteinases (Adams), and presenilins (Psen). Fmr1KO did not alter the nuclear/cytoplasmic abundance of App mRNA. Of 36 validated FMRP targets, 35 messages contained m6A peaks but only Agap2 mRNA was selectively enriched in Fmr1KO nucleus. The abundance of the APP processing enzymes Adam9 and Psen1 mRNA, which code for a minor alpha-secretase and gamma-secretase, respectively, were selectively enriched in wild type cytoplasm.


Assuntos
Proteínas ADAM/metabolismo , Adenosina/análogos & derivados , Núcleo Celular/metabolismo , Bases de Dados de Ácidos Nucleicos , Proteína do X Frágil de Retardo Mental/metabolismo , Proteínas de Membrana/metabolismo , Presenilina-1/metabolismo , RNA Mensageiro/metabolismo , Proteínas ADAM/genética , Transporte Ativo do Núcleo Celular/genética , Adenosina/genética , Adenosina/metabolismo , Animais , Núcleo Celular/genética , Proteína do X Frágil de Retardo Mental/genética , Proteínas de Membrana/genética , Camundongos , Presenilina-1/genética , RNA Mensageiro/genética
19.
Curr Top Behav Neurosci ; 42: 51-82, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31392630

RESUMO

Environmentally sensitive molecular mechanisms in the brain, such as DNA methylation, have become a significant focus of neuroscience research because of mounting evidence indicating that they are critical in response to social situations, stress, threats, and behavior. The recent identification of 5-hydroxymethylcytosine (5hmC), which is enriched in the brain (tenfold over peripheral tissues), raises new questions as to the role of this base in mediating epigenetic effects in the brain. The development of genome-wide methods capable of distinguishing 5-methylcytosine (5mC) from 5hmC has revealed that a growing number of behaviors are linked to independent disruptions of 5mC and 5hmC levels, further emphasizing the unique importance of both of these modifications in the brain. Here, we review the recent links that indicate DNA methylation (both 5mC and 5hmC) is highly dynamic and that perturbations in this modification may contribute to behaviors related to psychiatric disorders and hold clinical relevance.


Assuntos
Metilação de DNA , Epigenômica , Encéfalo , Epigênese Genética
20.
Curr Protoc Hum Genet ; 101(1): e81, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30620135

RESUMO

Mapping patterns of DNA methylation throughout the epigenome are critical to our understanding of several important biological and regulatory functions, such as transcriptional regulation, genomic imprinting, and embryonic development. The development and rapid advancement of next-generation sequencing (NGS) technologies have provided clinicians and researchers with accurate and reliable read-outs of genomic and epigenomic information at the nucleotide level. Such improvements have significantly lowered the cost required for genome-wide sequencing, facilitating the vast acquisition of data that has led to many improvements in patient care. However, the torrid rate of NGS data generation has left targeted validation approaches behind, including the confirmation of epigenetic marks such as DNA methylation. To overcome these shortcomings, we present a rapid and robust protocol for the parallel examination of multiple methylated sequences that we have termed simultaneous targeted methylation sequencing (sTM-Seq). Key features of this technique include the elimination of the need for large amounts of high-molecular weight DNA and the nucleotide specific distinction of both 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC). Moreover, sTM-Seq is scalable and can be used to investigate multiple loci in dozens of samples within a single sequencing run. By utilizing freely available web-based software and universal primers for multipurpose barcoding, library preparation, and customized sequencing, sTM-Seq is affordable, efficient, and widely applicable. Together, these features enable sTM-Seq to have wide-reaching clinical applications that will greatly improve turnaround rates for same-day procedures and allow clinicians to collect high-resolution data that can be used in a variety of patient settings. © 2019 by John Wiley & Sons, Inc.


Assuntos
Metilação de DNA/genética , Genoma/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Análise de Sequência de DNA/métodos , 5-Metilcitosina/análogos & derivados , 5-Metilcitosina/química , 5-Metilcitosina/metabolismo , DNA/genética , Primers do DNA/química , Primers do DNA/genética , Epigênese Genética , Genômica/tendências , Humanos , Software
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