Linked Life Data

7852359

Source:http://linkedlifedata.com/resource/pubmed/id/7852359

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1995-3-16
pubmed:abstractText
Ascorbate is an important cofactor in many cellular metabolic reactions and is intimately linked to iron homeostasis. Continuously cultured cells are ascorbate deficient due to the lability of the vitamin in solution and to the fact that daily supplementation of media with ascorbate is unusual. We found that ascorbate repletion alone did not alter ferritin synthesis. However, ascorbate-replete human hepatoma cells, Hep3B and HepG2, as well as K562 human leukemia cells achieved a substantially higher cellular ferritin content in response to a challenge with iron than did their ascorbate-deficient counterparts grown under standard culture conditions. Most of the elevation in ferritin content was due to an increase in de novo ferritin synthesis of greater than 50-fold, as shown by in vivo labeling with [35S]methionine and immunoprecipitation. RNA-blot analysis showed only minor changes in steady state levels of ferritin mRNA, suggesting that ascorbate enhances iron-induced ferritin synthesis primarily by post-transcriptional events. Transient gene expression experiments using chloramphenicol acetyltransferase reporter gene constructs showed that the ascorbate effect on ferritin translation is not mediated through the stem-loop near the translational start site that transduces ferritin synthesis in response to cytokines. The data suggest that ascorbate possibly modifies the action of the iron-responsive element on ferritin translation, although more precise structure-function studies are needed to clarify this issue. These data demonstrate a novel role of ascorbate as a signaling molecule in post-transcriptional gene regulation. The mechanism by which ascorbate modulates cellular iron metabolism is complex and requires additional detailed investigation.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
270
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2846-52
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Ascorbic acid enhances iron-induced ferritin translation in human leukemia and hepatoma cells.
pubmed:affiliation
Department of Medicine, Harvard Medical School, Brigham and Women's Hospital, Boston, Massachusetts 02115.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.