Activation of nuclear factor-kappaB during doxorubicin-induced apoptosis in endothelial cells and myocytes is pro-apoptotic: the role of hydrogen peroxide.
Doxorubicin (DOX) is a widely used anti-tumour drug. Cardiotoxicity is a major toxic side effect of DOX therapy. Although recent studies implicated an apoptotic pathway in DOX-induced cardiotoxicity, the mechanism of DOX-induced apoptosis remains unclear. In the present study, we investigated the role of reactive oxygen species and the nuclear transcription factor nuclear factor kappaB (NF-kappaB) during apoptosis induced by DOX in bovine aortic endothelial cells (BAECs) and adult rat cardiomyocytes. DOX-induced NF-kappaB activation is both dose- and time-dependent, as demonstrated using electrophoretic mobility-shift assay and luciferase and p65 (Rel A) nuclear-translocation assays. Addition of a cell-permeant iron metalloporphyrin significantly suppressed NF-kappaB activation and apoptosis induced by DOX. Overexpression of glutathione peroxidase, which detoxifies cellular H(2)O(2), significantly decreased DOX-induced NF-kappaB activation and apoptosis. Inhibition of DOX-induced NF-kappaB activation by a cell-permeant peptide SN50 that blocks translocation of the NF-kappaB complex into the nucleus greatly diminished DOX-induced apoptosis. Apoptosis was inhibited when IkappaB mutant vector, another NF-kappaB inhibitor, was added to DOX-treated BAECs. These results suggest that NF-kappaB activation in DOX-treated endothelial cells and myocytes is pro-apoptotic, in contrast with DOX-treated cancer cells, where NF-kappaB activation is anti-apoptotic. Removal of intracellular H(2)O(2) protects endothelial cells and myocytes from DOX-induced apoptosis, possibly by inhibiting NF-kappaB activation. These findings suggest a novel mechanism for enhancing the therapeutic efficacy of DOX.
Biophysics Research Institute and Free Radical Research Center, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.
Suwei
S
Wang
Srigiridhar
S
Kotamraju
Eugene
E
Konorev
Shasi
S
Kalivendi
Joy
J
Joseph
Balaraman
B
Kalyanaraman
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D001483:Base Sequence; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002417:Cattle; D002478:Cells, Cultured; D017931:DNA Primers; D004317:Doxorubicin / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D004789:Enzyme Activation; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D008297:Male; D009206:Myocardium / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley
D000975:Antioxidants; D017931:DNA Primers; D016328:NF-kappa B; D004317:Doxorubicin; D006861:Hydrogen Peroxide; C505410:Casp3 protein, rat; D053148:Caspase 3; D020169:Caspases