Linked Life Data

12609979

Source:http://linkedlifedata.com/resource/pubmed/id/12609979

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
19
pubmed:dateCreated
2003-5-5
pubmed:abstractText
Aging is generally accompanied by reduced tolerance to oxidative stress and altered responsiveness to proliferative signals. We have shown that hepatocytes derived from aged rats (24-26 months) exhibit greater sensitivity to H(2)O(2) treatment and reduced proliferation following epidermal growth factor (EGF) treatment than cells of young adult rats (5-6 months). Here we examined the effects of aging and calorie restriction (CR) on expression of the oxidative stress-inducible and pro-apoptotic gene gadd153 (chop) in these hepatocytes, and we investigated its influence on sensitivity to oxidants. We show that aging was associated with elevated expression of gadd153, both basally and in response to H(2)O(2) treatment. CR, which attenuates age-associated declines in stress tolerance, prevented the age-related increase in gadd153 expression. EGF treatment also resulted in gadd153 induction in old cells. This effect was absent in young cells and in old cells of CR rats. gadd153 induction by EGF was reactive oxygen species-dependent and correlated with heightened sensitivity to subsequent H(2)O(2) treatment, suggesting that elevated Gadd153 contributes to the greater sensitivity of EGF-pretreated old cells to oxidative stress. Additional support for this hypothesis was provided by experiments with Rat1 fibroblasts in which conditional expression of Gadd153 conferred increased sensitivity to H(2)O(2). We propose a model whereby the diminished ability of old hepatocytes to overcome an EGF-triggered reactive oxygen species load leads to induction of the proapoptotic gene gadd153, which, in turn, sensitizes the cells to oxidant injury. Our findings point to gadd153 expression levels as an important factor in liver aging.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
9
pubmed:volume
278
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
16726-31
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Expression of the pro-apoptotic gene gadd153/chop is elevated in liver with aging and sensitizes cells to oxidant injury.
pubmed:affiliation
Laboratory of Cellular and Molecular Biology, National Institute on Aging-IRP, Baltimore, Maryland 21224, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.