Exercise induces age-dependent changes on epigenetic parameters in rat hippocampus: A preliminary study.
ABSTRACT Regular exercise improves learning and memory, including during aging process. Interestingly, the imbalance of epigenetic mechanisms has been linked to age-related cognitive deficits. However, studies about epigenetic alterations after exercise during the aging process are rare. In this preliminary study we investigated the effect of aging and exercise on DNA methyltransferases (DNMT1 and DNMT3b) and H3-K9 methylation levels in hippocampus from 3 and 20-months aged Wistar rats. The animals were submitted to two exercise protocols: single session or chronic treadmill protocol. DNMT1 and H3-K9 methylation levels were decreased in hippocampus from aged rats. The single exercise session decreased both DNMT3b and DNMT1 levels in young adult rats, without any effect in the aged group. Both exercise protocols reduced H3-K9 methylation levels in young adult rats, while the single session reversed the changes on H3-K9 methylation levels induced by aging. Together, these results suggest that an imbalance on DNMTs and H3-K9 methylation levels might be linked to the brain aging process and that the outcome to exercise seems to vary through lifespan.
- SourceAvailable from: Lisa Monteggia[Show abstract] [Hide abstract]
ABSTRACT: Dynamic regulation of chromatin structure in postmitotic neurons plays an important role in learning and memory. Methylation of cytosine nucleotides has historically been considered the strongest and least modifiable of epigenetic marks. Accumulating recent data suggest that rapid and dynamic methylation and demethylation of specific genes in the brain may play a fundamental role in learning, memory formation, and behavioral plasticity. The current review focuses on the emergence of data that support the role of DNA methylation and demethylation, and its molecular mediators in memory formation.Dialogues in clinical neuroscience 09/2014; 16(3):359-71.
- [Show abstract] [Hide abstract]
ABSTRACT: Grandes esfuerzos han sido llevados a cabo para entender los componentes psicobiológicos del estrés y de algunas de las psicopatologías relacionadas con él, tales como los trastornos de ansiedad (ansiedad generalizada o crisis de pánico) e incluso la depresión. Existen evidencias de que procesos como la neurogénesis y la plasticidad se ven enormemente afectados por muchos factores, entre ellos el estrés. En esta revisión se presentan algunos de los principales conceptos sobre la relación entre estrés, plasticidad y neurogénesis, a los que se ha llegado a partir de investigaciones realizadas –principalmente en modelos animales–, desde hace algunas décadas. Se realizará una diferenciación entre los efectos ocasionados por estrés crónico y agudo, tratando de establecer las interacciones que sobre estos efectos ejercen algunas variables tales como el género o el rango de edad, se enfatizarán los efectos comportamentales para finalmente revisar algunas de las formas de intervención actualmente más usadas para el tratamiento del estrés.Universitas Psychologica 09/2014; 13(3):1181-1214. DOI:10.11144/Javeriana.UPSY13-3.eepp · 0.40 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Chromatin modifying enzymes DNA methyltransferases (DNMTs), histone deacetylase (HDAC) 2 and CREB binding protein (CBP) play a crucial role in memory, particularly during consolidation process which declines with advancing age. However, the expression of these enzymes and their effect on memory consolidation during aging are not clearly understood. In the present study, novel object recognition test was used to assess the memory consolidation followed by expression analysis of DNMTs, HDAC2 and CBP in the cerebral cortex and hippocampus of young, adult and old male mice. Object recognition memory was reduced in old as compared to young and adult. DNMT1 protein expression was high in the cerebral cortex and hippocampus of young male mice, but declined gradually with age. On the other hand, HDAC2 mRNA and protein expression increased in the hippocampus of old male mice as compared to young and adult. Alteration in the expression of these enzymes is correlated with reduced recognition memory in old.Biogerontology 06/2014; 15(4). DOI:10.1007/s10522-014-9504-5 · 3.01 Impact Factor