Environmental enrichment modulates 5-hydroxymethylcytosine dynamics in hippocampus
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE61194 | GEO | 2014/09/11
SECONDARY ACCESSION(S): PRJNA260671
REPOSITORIES: GEO
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Project description:Gene-environment interactions mediated at the epigenetic level may provide an initial step in delivering an appropriate response to environmental changes. 5-hydroxymethylcytosine (5hmC), a DNA base derived from 5-methylcytosine (5mC), accounts for ~40% of modified cytosine in brain and has been implicated in DNA methylation-related plasticity. To identify the role of 5hmC in gene-environment interactions, we exposed both young (6-week-old) and aged (18-month-old) mice to both an enriched environment and a standard environment. Exposure to EE significantly improves learning and memory in aged mice and reduces 5hmC abundance in mouse hippocampus. Furthermore, we mapped the genome-wide distribution of 5hmC and found that the alteration of 5hmC modification occurred mainly at gene bodies. In particular, genes involved in axon guidance are enriched among the genes with altered 5hmC modification. These results together suggest that environmental enrichment could modulate the dynamics of 5hmC in hippocampus, which could potentially contribute to improved learning and memory in aged animals. To identify the role of 5hmC in gene-environment interactions, we exposed both young (6-week-old) and aged (18-month-old) C57B/6 mice to both an enriched environment (EE) and a standard environment. Exposure of mice to EE was achieved by keeping a group of mice in the EE chamber, which is larger than the standard cage, includes novel objects, such as toys of varied color and texture, tunnels, an exercise wheel for voluntary exercise, and extra bedding material, along with free access to food and water. Daily exposure to EE was kept at 5 hours during the daylight cycle for 4 consecutive weeks. Control animals were kept in their small cages that are used as standard housing cages (CE) containing bedding, food and access to water. YC, young mice exposing to control environment, YE, young mice exposing to enriched environment, AC, aged mice exposing to control environment, AE, aged mice exposed to enriched environment. Please note that 5hmC-containing DNA enrichment method was inspired by a unique character of beta-glucotransferase that can specifically add glucose to 5hmC modification. With a modified glucose conjugated with biotin, we are able to purify the 5hmC-containing DNA by biotin-streptavidin-based immunoprecipitation.
2014-09-11 | E-GEOD-61194 | biostudies-arrayexpress
Project description:Aging is associated with a decline in hippocampal mediated learning and memory, a process which can be ameliorated by dietary (caloric) restriction. We used Affymetrix gene expression analysis to monitor changes in three regions of the hippocampus (CA1, CA3, DG) of middle aged (18 months) and old (28 month) rats that were exposed to dietary restriction. Old rats were determined to be good performers (GP) or poor performers (PP) in behavioural tests to assess their hippocampal function. We used Affymetrix gene expression analysis to monitor changes in three regions of the hippocampus (CA1, CA3, DG) of middle aged (18 months) and old (28 month) rats that were exposed to dietary restriction.
2010-06-08 | E-GEOD-21681 | biostudies-arrayexpress
Project description:The epigenetic changes of the chromatin represent an attractive molecular substrate for adaptation to the environment. We examined here the role of CBP, a histone acetyltransferase involved in mental retardation, in the genesis and maintenance of long-lasting systemic and behavioral adaptations to environmental enrichment (EE). Morphological and behavioral analyses demonstrated that EE ameliorates deficits associated to CBP-deficiency. However, CBP-deficient mice also showed a strong defect in environment-induced neurogenesis and impaired EE-enhanced spatial navigation and patter separation ability. These defects correlated with an attenuation of the transcriptional program induced in response to EE and with deficits in histone acetylation at the promoters of EE-regulated, neurogenesis-related genes. Additional experiments in CBP restricted and inducible knockout mice indicated that environment-induced adult neurogenesis is extrinsically regulated by CBP function in mature granule cells. Overall, our experiments demonstrate that the environment alters gene expression by impinging on activities involved in modifying the epigenome and identify CBP-dependent transcriptional neuroadaptation as an important mediator of EE-induced benefits, a finding with important implications for mental retardation therapeutics. To identify those genes whose expression was altered in the hippocampus of cbp heterozygous mice both under basal conditions and after 2 weeks of exposure to environmental enrichment, we performed a gene profiling analysis of hippocampal tissue using high-density oligonucleotide microarrays. We obtained quintuplicate (standard housing) and triplicate (environmental enrichment) samples containing total RNA from the hippocampi of four 3-month old females of either genotype (in total 32 cbp+/- mice and 32 wild type littermates were used in the experiment).
2011-08-29 | E-GEOD-30880 | biostudies-arrayexpress
Project description:Aging is often associated with cognitive decline, but many elderly individuals maintain a high level of function throughout life. Here we studied outbred rats, which also exhibit individual differences across a spectrum of outcomes that includes both preserved and impaired spatial memory. Previous work in this model identified the CA3 subfield of the hippocampus as a region critically affected by age and integral to differing cognitive outcomes. Earlier microarray profiling revealed distinct gene expression profiles in the CA3 region, under basal conditions, for aged rats with intact memory and those with impairment. Because prominent age-related deficits within the CA3 occur during neural encoding of new information, here we used microarray analysis to gain a broad perspective of the aged CA3 transcriptome under activated conditions. Behaviorally induced CA3 expression profiles differentiated aged rats with intact memory from those with impaired memory. In the activated profile, we observed substantial numbers of genes (greater than 1000) exhibiting increased expression in aged unimpaired rats relative to aged impaired, including many involved in synaptic plasticity and memory mechanisms. This unimpaired aged profile also overlapped significantly with a learning induced gene profile previously acquired in young adults. Alongside the increased transcripts common to both young learning and aged rats with preserved memory, many transcripts behaviorally-activated in the current study had previously been identified as repressed in the aged unimpaired phenotype in basal expression. A further distinct feature of the activated profile of aged rats with intact memory is the increased expression of an ensemble of genes involved in inhibitory synapse function, which could control the phenotype of neural hyperexcitability found in the CA3 region of aged impaired rats. These data support the conclusion that aged subjects with preserved memory recruit adaptive mechanisms to retain tight control over excitability under both basal and activated conditions. RNA profiles from cognitively unimpaired and impaired aged rats were compared under 2 conditions: spatial learning task and a non-spatial learning task.
2013-12-16 | E-GEOD-47867 | biostudies-arrayexpress
Project description:Aging is associated with a decline in hippocampal mediated learning and memory, a process wich can be ameliorated by dietary (caloric) restriction. We used Affymetrix gene expression analysis to monitor changes in three regions of the hippocampus (CA1, CA3, DG) of middle aged (18 months) and old (28 month) rats that were exposed to dietary restriction. Old rats were determined to be good performers (GP) or poor performers (PP) in behavioral tests to assess thier hippocampal function.
2010-05-25 | GSE21681 | GEO
Project description:We carried out a global survey of age-related changes in mRNA levels in the C57BL/6NIA mouse hippocampus and found a difference in the hippocampal gene expression profile between 2-month-old young mice and 15-month-old middle-aged mice correlated with an age-related cognitive deficit in hippocampal-based explicit memory formation. Middle-aged mice displayed a mild but specific deficit in spatial memory in the Morris water maze. Experiment Overall Design: No technical replicates; 14 biological replicates for 15-month-old mice, 9 biological replicates for 2-month-old mice. Whole hippocampus.
2007-11-27 | E-GEOD-5078 | biostudies-arrayexpress
Project description:Aged brain is associated with an inevitable decline in cognitive functions and increased vulnerability to neurodegenerative disorders. Multiple molecular hallmarks have been associated with the aging nervous system through transcriptomics and proteomic studies. Recently, the field of epitranscriptomics highlights the role of RNA chemical modification in various biological processes. In particular, N6-methyladenosine (m6A), the most abundant internal modification in eukaryotic mRNAs, has been functionally linked to multiple aspects of RNA processing. Importantly, the functional roles of m6A in neurophysiology, such as in the process of learning and memory, have led to our current investigation of how m6A-transcriptomic landscape is shaped during aging. Using the inbred C57Bl/6 line, we compared the m6A-transcriptomic profiles from the hippocampi of young (3-month-old) and aged (20-month-old) mice. The methylated RNA immunoprecipitation (MeRIP)-sequencing analysis revealed hyper- and hypo-methylation in 426 and 102 genes, respectively, in the aged hippocampus (fold-change >1.5, FDR<0.05). By correlating the methylation changes to their steady state transcript levels in the RNA-seq, we found a significant concordance between m6A and transcript levels in either direction.
2022-11-28 | GSE217883 | GEO
Project description:Aged brain is associated with an inevitable decline in cognitive functions and increased vulnerability to neurodegenerative disorders. Multiple molecular hallmarks have been associated with the aging nervous system through transcriptomics and proteomic studies. Recently, the field of epitranscriptomics highlights the role of RNA chemical modification in various biological processes. In particular, N6-methyladenosine (m6A), the most abundant internal modification in eukaryotic mRNAs, has been functionally linked to multiple aspects of RNA processing. Importantly, the functional roles of m6A in neurophysiology, such as in the process of learning and memory, have led to our current investigation of how m6A-transcriptomic landscape is shaped during aging. Using the inbred C57Bl/6 line, we compared the m6A-transcriptomic profiles from the hippocampi of young (3-month-old) and aged (20-month-old) mice. The methylated RNA immunoprecipitation (MeRIP)-sequencing analysis revealed hyper- and hypo-methylation in 426 and 102 genes, respectively, in the aged hippocampus (fold-change >1.5, FDR<0.05). By correlating the methylation changes to their steady state transcript levels in the RNA-seq, we found a significant concordance between m6A and transcript levels in either direction.
2022-11-28 | GSE217882 | GEO
Project description:The epigenetic changes of the chromatin represent an attractive molecular substrate for adaptation to the environment. We examined here the role of CBP, a histone acetyltransferase involved in mental retardation, in the genesis and maintenance of long-lasting systemic and behavioral adaptations to environmental enrichment (EE). Morphological and behavioral analyses demonstrated that EE ameliorates deficits associated to CBP-deficiency. However, CBP-deficient mice also showed a strong defect in environment-induced neurogenesis and impaired EE-enhanced spatial navigation and patter separation ability. These defects correlated with an attenuation of the transcriptional program induced in response to EE and with deficits in histone acetylation at the promoters of EE-regulated, neurogenesis-related genes. Additional experiments in CBP restricted and inducible knockout mice indicated that environment-induced adult neurogenesis is extrinsically regulated by CBP function in mature granule cells. Overall, our experiments demonstrate that the environment alters gene expression by impinging on activities involved in modifying the epigenome and identify CBP-dependent transcriptional neuroadaptation as an important mediator of EE-induced benefits, a finding with important implications for mental retardation therapeutics. To identify those genes whose expression was altered in the hippocampus of cbp heterozygous mice both under basal conditions and after 2 weeks of exposure to environmental enrichment, we performed a gene profiling analysis of hippocampal tissue using high-density oligonucleotide microarrays.
2011-08-30 | GSE30880 | GEO
Project description:The ability to form memories is a prerequisite for an organismâs behavioural adaptation to environmental changes. At the molecular level, the acquisition and maintenance of memory requires changes in chromatin modifications. In an effort to unravel the epigenetic network underlying both short- and long-term memory, we examined chromatin modification changes in two distinct mouse brain regions, two cell-types, and three time-points before and after contextual learning. Here we show that histone modifications predominantly change during memory acquisition and correlate surprisingly little with changes in gene expression. While long-lasting changes are almost exclusive to neurons, learning-related histone modification and DNA methylation changes occur also in non-neuronal cell types, suggesting a functional role for non-neuronal cells in epigenetic learning. Finally, our data provides evidence for a molecular framework of memory acquisition and maintenance, wherein DNA methylation could alter the expression and splicing of genes involved in functional plasticity and synaptic wiring. We examined chromatin modification changes in two distinct mouse brain regions (CA1 and ACC), two cell-types (neurons, non-neurons), and three time-points before and after contextual learning (naive, 1h, 4w).
2015-11-24 | E-GEOD-74966 | biostudies-arrayexpress