Linked Life Data

12603320

Source:http://linkedlifedata.com/resource/pubmed/id/12603320

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2003-2-26
pubmed:abstractText
The effects of physiologically relevant hypoxia on the catalytic activity of cytochrome c oxidase (CytOX), mitochondrial gene expression, and both nuclear and mitochondrial encoded CytOX mRNA levels were investigated in murine monocyte macrophages, mouse C2C12 skeletal myocytes and rat adrenal pheochromocytoma PC12 cells. Our results suggest a coordinated down regulation of mitochondrial genome-coded CytOX I and II and nuclear genome-coded CytOX IV and Vb mRNAs during hypoxia. Hypoxia also caused a severe decrease in mitochondrial transcription rates, and associated decrease in mitochondrial transcription factor A. The enzyme from hypoxia exposed cells exhibited altered subunit content as revealed by blue native gel electrophoresis. There was a generalized decline in mitochondrial function that led to a decrease in total cellular heme and ATP pools. We also observed a decrease in mitochondrial heme aa3 content and decreased levels of CytOX subunit I, IV and Vb, though the catalytic efficiency of the enzyme (TN for cytochrome c oxidase) remained nearly the same. Increased glycolytic flux and alterations in the kinetic characteristics of the CytOX might be the two mechanisms by which hypoxic cells maintain adequate ATP levels to sustain life processes. Reoxygenation nearly completely reversed hypoxia-mediated changes in CytOX mRNA contents, rate of mitochondrial transcription, and the catalytic activity of CytOX enzyme. Our results show adaptive changes in CytOX structure and activity during physiological hypoxia.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0014-2956
pubmed:author
pubmed:issnType
Print
pubmed:volume
270
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
871-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Adaptive changes in the expression of nuclear and mitochondrial encoded subunits of cytochrome c oxidase and the catalytic activity during hypoxia.
pubmed:affiliation
Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, 3800 Spruce Street, Philadelphia, PA 19104, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.