Linked Life Data

19828835

Source:http://linkedlifedata.com/resource/pubmed/id/19828835

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2009-12-1
pubmed:abstractText
Transferrin receptor (TFR) 1 and 2 are expressed in the liver; TFR1 levels are regulated by cellular iron levels while TFR2 levels are regulated by transferrin saturation. The aims of this study were to 1) determine the relative importance of TFR1 and TFR2 in transferrin-bound iron (TBI) uptake by HuH7 human hepatoma cells and 2) characterize the role of metal-transferrin complexes in the regulation of these receptors. TFR expression was altered by 1) incubation with metal-transferrin (Tf) complexes, 2) TFR1 and TFR2 small interfering RNA knockdown, and 3) transfection with a human TFR2 plasmid. TBI uptake was measured using (59)Fe-(125)I-labeled Tf and mRNA and protein expression by real-time PCR and Western blot analysis, respectively. Fe(2)Tf, Co(2)Tf, and Mn(2)Tf increased TFR2 protein expression, indicating that the upregulation was not specifically regulated by iron-transferrin but also other metal-transferrins. In addition, Co(2)Tf and Mn(2)Tf upregulated TFR1, reduced ferritin, and increased hypoxia-inducible factor-1alpha protein expression, suggesting that TFR1 upregulation was due to a combination of iron deficiency and chemical hypoxia. TBI uptake correlated with changes in TFR1 but not TFR2 expression. TFR1 knockdown reduced iron uptake by 80% while TFR2 knockdown did not affect uptake. At 5 microM transferrin, iron uptake was not affected by combined TFR1 and TFR2 knockdown. Transfection with a hTFR2 plasmid increased TFR2 protein expression, causing a 15-20% increase in iron uptake and ferritin levels. This shows for the first time that TFR-mediated TBI uptake is mediated primarily via TFR1 but not TFR2 and that a high-capacity TFR-independent pathway exists in hepatoma cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1522-1563
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
297
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
C1567-75
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
The role of transferrin receptor 1 and 2 in transferrin-bound iron uptake in human hepatoma cells.
pubmed:affiliation
The Univ. of Western Australia, Fremantle Hospital, Australia.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't