Down-regulation of acyl-CoA oxidase gene expression and increased NF-kappaB activity in etomoxir-induced cardiac hypertrophy.
Activation of nuclear factor-kappaB (NF-kappaB) is required for hypertrophic growth of cardiomyocytes. Etomoxir is an irreversible inhibitor of carnitine palmitoyltransferase I (CPT-I) that activates peroxisome proliferator-activated receptor alpha (PPARalpha) and induces cardiac hypertrophy through an unknown mechanism. We studied the mRNA expression of genes involved in fatty acid oxidation in the heart of mice treated for 1 or 10 days with etomoxir (100 mg/kg/day). Etomoxir administration for 1 day significantly increased (4.4-fold induction) the mRNA expression of acyl-CoA oxidase (ACO), which catalyzes the rate-limiting step in peroxisomal beta-oxidation. In contrast, etomoxir treatment for 10 days dramatically decreased ACO mRNA levels by 96%. The reduction in ACO expression in the hearts of 10-day etomoxir-treated mice was accompanied by an increase in the mRNA expression of the antioxidant enzyme glutathione peroxidase and the cardiac marker of oxidative stress bax. Moreover, the activity of the redox-regulated transcription factor NF-kappaB was increased in heart after 10 days of etomoxir treatment. Overall, the findings here presented show that etomoxir treatment may induce cardiac hypertrophy via increased cellular oxidative stress and NF-kappaB activation.
Cabrero
Agatha
A
Unitat de Farmacologia, Departament de Farmacologia i Química Terapeùtica, Facultat de Farmàcia, Universitat de Barcelona, Spain.
Merlos
Manuel
M
Laguna
Juan C
JC
Carrera
Manuel Vázquez
MV
D042962:Acyl-CoA Oxidase / Q000235:genetics* / Q000378:metabolism*; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D051836:COUP Transcription Factors; D006332:Cardiomegaly / Q000139:chemically induced / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D015536:Down-Regulation; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D004852:Epoxy Compounds / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects*; D008297:Male; D051379:Mice; D009206:Myocardium / Q000166:cytology / Q000201:enzymology; D016328:NF-kappa B / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D018384:Oxidative Stress; D012333:RNA, Messenger / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism; D018168:Receptors, Retinoic Acid / Q000235:genetics / Q000378:metabolism; D011987:Receptors, Steroid; D047488:Retinoid X Receptors; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
D001786:Blood Glucose; D051836:COUP Transcription Factors; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D004852:Epoxy Compounds; D016328:NF-kappa B; D009687:Nuclear Proteins; D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D018168:Receptors, Retinoic Acid; D011987:Receptors, Steroid; D047488:Retinoid X Receptors; D014157:Transcription Factors; D042962:Acyl-CoA Oxidase; C054207:etomoxir