Linked Life Data

15589375

Source:http://linkedlifedata.com/resource/pubmed/id/15589375

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2004-12-13
pubmed:abstractText
Heme oxygenases (HO-1 and HO-2) catalyze the NADPH-cytochrome P(450) reductase (CPR)-dependent degradation of heme into iron, carbon monoxide, and biliverdin, which is reduced into bilirubin. Under basal conditions, HO-1 is often undetected and can be induced by numerous stress conditions. Although HO-2 is constitutively expressed, its activity appears to be regulated by post-translational modifications. HO activity has been associated with cellular protection, by which it degrades heme, a prooxidant, into bioactive metabolites. Under given circumstances, overexpression of HO-1 can render cells more sensitive to free radicals. Here, we investigated the properties of human HO isoforms that protect against oxidative stress. Considering that CPR can be a limiting factor for optimal HO activity, we tested stable HO-1 and HO-2 cell lines that derived from the CPR cells. Results indicate that the HO-1 and HO-2 cells are more resistant than controls to hemin and to the organic tert-butyl hydroperoxide, t-BuOOH. However, HO-1 cells are less resistant than HO-2 cells to hydrogen peroxide (H(2)O(2)). The levels of oxidatively modified proteins of HO-1 and HO-2 cells in response to t-BuOOH toxicity are identical, but the level of oxidatively modified proteins of HO-2 cells is less than that of HO-1 cells in response to H(2)O(2) toxicity. Performing subcellular fractionations revealed that HO-2 and CPR are found together in the microsomal fractions, whereas HO-1 is partially present in the microsome and also found in other fractions, such as the cytosol. These same findings were observed in non-transfected primary neurons where HO-1 proteins were chemically induced with 15-deoxy-Delta(12,14)-prostaglandin J(2) (15dPGJ(2)). The differences in subcellular localization of HO-1 and HO-2 could explain some of the discrepancies in their cellular activity and enzymatic protective mechanisms.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/15-deoxyprostaglandin J2, http://linkedlifedata.com/resource/pubmed/chemical/HMOX1 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Heme Oxygenase (Decyclizing), http://linkedlifedata.com/resource/pubmed/chemical/Heme Oxygenase-1, http://linkedlifedata.com/resource/pubmed/chemical/Hemin, http://linkedlifedata.com/resource/pubmed/chemical/Hydrogen Peroxide, http://linkedlifedata.com/resource/pubmed/chemical/Isoenzymes, http://linkedlifedata.com/resource/pubmed/chemical/Membrane Proteins, http://linkedlifedata.com/resource/pubmed/chemical/NADPH-Ferrihemoprotein Reductase, http://linkedlifedata.com/resource/pubmed/chemical/Prostaglandin D2, http://linkedlifedata.com/resource/pubmed/chemical/heme oxygenase-2, http://linkedlifedata.com/resource/pubmed/chemical/tert-Butylhydroperoxide
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0891-5849
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
38
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
85-92
pubmed:dateRevised
2009-10-1
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Distinct protective mechanisms of HO-1 and HO-2 against hydroperoxide-induced cytotoxicity.
pubmed:affiliation
Department of Anesthesiology/Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD 21205, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't