A Role of Epigenetics in Aging and the Age-Dependent Response to Ionizing Radiation
Date
2014-10-03
Authors
Sidler, Corinne
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Journal ISSN
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Publisher
Lethbridge, Alta. : University of Lethbridge, Dept. of Biological Sciences.
Abstract
Aging is associated with the functional decline of organs, and results in age-dependent differences in stress-sensitivity. Younger animals are more sensitive to mutagenic insults than adults, whereas in plants, the transition to reproductive growth is the most stress-sensitive.
Here, we show a role of reduced H3K9 trimethylation and corresponding genomic instability in the aging rat thymus and in senescence of human fibroblasts. A similar reduction of SUV39H1 expression was observed in response to ionizing radiation (IR), which correlated with the induction of senescence.
In plants exposed to IR during the transition to reproductive growth, histone methyltransferases were up-regulated, which correlated with reduced transcription of transposable elements.
This difference in response may be reflected in the differences in life cycles. Whereas plants rely on the survival and genome integrity of meristematic cells for their reproductive success, in mammals, limiting the cell division in cells that have incurred damage may be crucial.
Description
Keywords
aging , genomic instability , histone methyltransferases , human fibroblasts , ionizing radiation , life cyces