title: Cardiac myocyte gene expression profiling during H2O2-induced apoptosis.
abstract: High levels of oxidative stress promote cardiac myocyte death, though lower levels are potentially cytoprotective/anabolic. We examined the changes in gene expression in rat neonatal cardiac myocytes exposed to apoptotic (0.2 mM) or nontoxic (0.04 mM) concentrations of H2O2 (2, 4, or 24 h) using Affymetrix microarrays. Using U34B arrays, we identified a ubiquitously expressed, novel H2O2-responsive gene [putative peroxide-inducible transcript 1 (Perit1)], which generates two alternatively spliced transcripts. Using 230 2.0 arrays, H2O2 (0.04 mM) promoted significant changes in expression of only 32 genes, all of which were seen with 0.2 mM H2O2. We failed to detect any increase in the rate of protein synthesis in cardiac myocytes exposed to <0.1 mM H2O2, further suggesting that global, low concentrations of H2O2 are not anabolic in this system. H2O2 (0.2 mM) promoted significant (P < 0.05, >1.75-fold) changes in expression of 649 mRNAs and 187 RNAs corresponding to no established gene. Of the mRNAs, 114 encoded transcriptional regulators including Krüppel-like factors (Klfs). Quantitative PCR independently verified the changes in Klf expression. Thus, H2O2-induced cardiac myocyte apoptosis is associated with dynamic changes in gene expression. The expression of these genes and their protein products potentially influences the progression of the apoptotic response.
authors.affiliation: National Heart and Lung Institute Division, Faculty of Medicine, Imperial College London, London, United Kingdom. a.clerk@imperial.ac.uk
authors.forename: Angela
authors.initials: A
authors.lastname: Clerk
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Kemp
authors.forename: Georgia
authors.initials: G
authors.lastname: Zoumpoulidou
authors.forename: Peter H
authors.initials: PH
authors.lastname: Sugden
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D015152:Blotting, Northern; D019295:Computational Biology; D017931:DNA Primers; D020224:Expressed Sequence Tags; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects*; D006861:Hydrogen Peroxide / Q000633:toxicity*; D046228:Microarray Analysis; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000378:metabolism*; D018384:Oxidative Stress / Q000502:physiology*; D011506:Proteins / Q000235:genetics* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D017931:DNA Primers; C521803:Oser1 protein, rat; D011506:Proteins; D006861:Hydrogen Peroxide