Hippocampal TET1 and TET2 expression and DNA hydroxymethylation are affected by physical exercise in aged mice

The function of 5-hydroxymethylcytosine (5hmC) is poorly understood. 5hmC is an epigenetic modification of DNA, resulting from the oxidation of 5-methylcytosine (5mC) by the Fe2+, and 2-oxoglutarate-dependent, 10–11 translocation methylcytosine dioxygenases (TET1, TET2, and TET3). Recent evidence su...

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Main Authors: Jessop, Peter, Toledo-Rodriguez, Maria
Format: Article
Language:English
Published: Frontiers Media 2018
Subjects:
Online Access:https://eprints.nottingham.ac.uk/51371/
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author Jessop, Peter
Toledo-Rodriguez, Maria
author_facet Jessop, Peter
Toledo-Rodriguez, Maria
author_sort Jessop, Peter
building Nottingham Research Data Repository
collection Online Access
description The function of 5-hydroxymethylcytosine (5hmC) is poorly understood. 5hmC is an epigenetic modification of DNA, resulting from the oxidation of 5-methylcytosine (5mC) by the Fe2+, and 2-oxoglutarate-dependent, 10–11 translocation methylcytosine dioxygenases (TET1, TET2, and TET3). Recent evidence suggests that, in addition to being an intermediate in active demethylation, 5hmC may also have an epigenetic role. 5hmC is enriched in the adult brain, where it has been implicated in regulating neurogenesis. The rate of adult neurogenesis decreases with age, however physical exercise has been shown to counteract this deficit. Here, we investigated the impact of voluntary exercise on the age-related changes of TET1, TET2, expression and 5hmC content in the hippocampus and hypothalamus. For this purpose, we used voluntary exercise in young adult (3 months) and aged (18 months) mice as a rodent model of healthy brain aging. We measured the levels of hippocampal and hypothalamic TET1, TET2 mRNA, and 5hmC and memory [Object Location (OL) test] in mice that either exercised for 1 month or remained sedentary. While aging was associated with decreased TET1 and TET2 expression, voluntary exercise counteracted the decline in expression. Moreover, aged mice that exercised had higher hippocampal 5hmC content in the promoter region of miR-137, an miRNA involved in adult neurogenesis. Exercise improved memory in aged mice, and there was a positive correlation between 5hmC miR-137 levels and performance in the OL test. In the hypothalamus neither exercise nor aging affected TET1 or TET2 expression. These results suggest that exercise partially restores the age-related decrease in hippocampal TET1 and TET2 expression, which may be linked to the improvement in memory. Future studies should further determine the specific genes where changes in 5hmC levels may mediate the exercise-induced improvements in memory and neurogenesis in aged animals.
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spelling nottingham-513712018-04-26T01:30:29Z https://eprints.nottingham.ac.uk/51371/ Hippocampal TET1 and TET2 expression and DNA hydroxymethylation are affected by physical exercise in aged mice Jessop, Peter Toledo-Rodriguez, Maria The function of 5-hydroxymethylcytosine (5hmC) is poorly understood. 5hmC is an epigenetic modification of DNA, resulting from the oxidation of 5-methylcytosine (5mC) by the Fe2+, and 2-oxoglutarate-dependent, 10–11 translocation methylcytosine dioxygenases (TET1, TET2, and TET3). Recent evidence suggests that, in addition to being an intermediate in active demethylation, 5hmC may also have an epigenetic role. 5hmC is enriched in the adult brain, where it has been implicated in regulating neurogenesis. The rate of adult neurogenesis decreases with age, however physical exercise has been shown to counteract this deficit. Here, we investigated the impact of voluntary exercise on the age-related changes of TET1, TET2, expression and 5hmC content in the hippocampus and hypothalamus. For this purpose, we used voluntary exercise in young adult (3 months) and aged (18 months) mice as a rodent model of healthy brain aging. We measured the levels of hippocampal and hypothalamic TET1, TET2 mRNA, and 5hmC and memory [Object Location (OL) test] in mice that either exercised for 1 month or remained sedentary. While aging was associated with decreased TET1 and TET2 expression, voluntary exercise counteracted the decline in expression. Moreover, aged mice that exercised had higher hippocampal 5hmC content in the promoter region of miR-137, an miRNA involved in adult neurogenesis. Exercise improved memory in aged mice, and there was a positive correlation between 5hmC miR-137 levels and performance in the OL test. In the hypothalamus neither exercise nor aging affected TET1 or TET2 expression. These results suggest that exercise partially restores the age-related decrease in hippocampal TET1 and TET2 expression, which may be linked to the improvement in memory. Future studies should further determine the specific genes where changes in 5hmC levels may mediate the exercise-induced improvements in memory and neurogenesis in aged animals. Frontiers Media 2018-04-19 Article PeerReviewed application/pdf en cc_by https://eprints.nottingham.ac.uk/51371/1/fcell-06-00045.pdf Jessop, Peter and Toledo-Rodriguez, Maria (2018) Hippocampal TET1 and TET2 expression and DNA hydroxymethylation are affected by physical exercise in aged mice. Frontiers in Cell and Developmental Biology, 6 . 45/1-45/9. ISSN 2296-634X TET1; TET2; 5hmC; Exercise; Aging; Hippocampus https://doi.org/10.3389/fcell.2018.00045 doi:10.3389/fcell.2018.00045 doi:10.3389/fcell.2018.00045
spellingShingle TET1; TET2; 5hmC; Exercise; Aging; Hippocampus
Jessop, Peter
Toledo-Rodriguez, Maria
Hippocampal TET1 and TET2 expression and DNA hydroxymethylation are affected by physical exercise in aged mice
title Hippocampal TET1 and TET2 expression and DNA hydroxymethylation are affected by physical exercise in aged mice
title_full Hippocampal TET1 and TET2 expression and DNA hydroxymethylation are affected by physical exercise in aged mice
title_fullStr Hippocampal TET1 and TET2 expression and DNA hydroxymethylation are affected by physical exercise in aged mice
title_full_unstemmed Hippocampal TET1 and TET2 expression and DNA hydroxymethylation are affected by physical exercise in aged mice
title_short Hippocampal TET1 and TET2 expression and DNA hydroxymethylation are affected by physical exercise in aged mice
title_sort hippocampal tet1 and tet2 expression and dna hydroxymethylation are affected by physical exercise in aged mice
topic TET1; TET2; 5hmC; Exercise; Aging; Hippocampus
url https://eprints.nottingham.ac.uk/51371/
https://eprints.nottingham.ac.uk/51371/
https://eprints.nottingham.ac.uk/51371/