title: Corticosteroids inhibit cell death induced by doxorubicin in cardiomyocytes: induction of antiapoptosis, antioxidant, and detoxification genes.
abstract: Psychological or physical stress induces an elevation of corticosteroids in the circulating system. We report here that corticosterone (CT) protects cardiomyocytes from apoptotic cell death induced by doxorubicin (Dox), an antineoplastic drug known to induce cardiomyopathy possibly through reactive oxygen species production. The cytoprotection induced by CT is within the range of physiologically relevant doses. The lowest dose tested, 0.1 microM (or 3.5 microg/dl), inhibited apoptosis by approximately 25% as determined by caspase activity. With 1 microM CT, cardiomyocytes gain a cytoprotective effect after 8 h of incubation and remain protected for at least 72 h. Hydrocortisone, cortisone, dexamethasone, and aldosterone but not androstenedione or cholesterol also induced cytoprotection. Analyses of 20,000 gene expression sequences using Affymetrix high-density oligonucleotide array found that CT caused up-regulation of 140 genes and down-regulation of 108 genes over 1.5-fold. Among the up-regulated genes are bcl-xL, metallothioneins, glutathione peroxidase-3, and glutathione S-transferases. Western blot analyses revealed that CT induced an elevation of bcl-xL but not bcl-2 or proapoptotic factors bax, bak, and bad. Inhibiting the expression of bcl-xL reduced the cytoprotective effect of CT. Our data suggest that CT induces a cytoprotective effect on cardiomyocytes in association with reprogramming gene expression and induction of bcl-xL gene.
authors.affiliation: Department of Pharmacology, University of Arizona, 1501 N. Campbell Avenue, Tucson, AZ 85724, USA. qchen@email.arizona.edu
authors.forename: Qin M
authors.initials: QM
authors.lastname: Chen
authors.forename: Donnia
authors.initials: D
authors.lastname: Alexander
authors.forename: Haipeng
authors.initials: H
authors.lastname: Sun
authors.forename: Lifang
authors.initials: L
authors.lastname: Xie
authors.forename: Yan
authors.initials: Y
authors.lastname: Lin
authors.forename: Jerome
authors.initials: J
authors.lastname: Terrand
authors.forename: Steve
authors.initials: S
authors.lastname: Morrissy
authors.forename: Sally
authors.initials: S
authors.lastname: Purdom
mesh_terms: D000305:Adrenal Cortex Hormones / Q000494:pharmacology*; D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D016923:Cell Death / Q000187:drug effects / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D004317:Doxorubicin / Q000633:toxicity*; D008658:Inactivation, Metabolic / Q000235:genetics*; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D000305:Adrenal Cortex Hormones; D000975:Antioxidants; D004317:Doxorubicin