title: Acute toxicity of doxorubicin on isolated perfused heart: response of kinases regulating energy supply.
abstract: Doxorubicin (DXR) is a widely used and efficient anticancer drug. However, its application is limited by the risk of severe cardiotoxicity. Impairment of cardiac high-energy phosphate homeostasis is an important manifestation of both acute and chronic DXR cardiotoxic action. Using the Langendorff model of the perfused rat heart, we characterized the acute effects of 1-h perfusion with 2 or 20 microM DXR on two key kinases in cardiac energy metabolism, creatine kinase (CK) and AMP-activated protein kinase (AMPK), and related them to functional responses of the perfused heart and structural integrity of the contractile apparatus as well as drug accumulation in cardiomyocytes. DXR-induced changes in CK were dependent on the isoenzyme, with a shift in protein levels of cytosolic isoenzymes from muscle-type CK to brain-type CK, and a destabilization of octamers of the mitochondrial isoenzyme (sarcometric mitochondrial CK) accompanied by drug accumulation in mitochondria. Interestingly, DXR rapidly reduced the protein level and phosphorylation of AMPK as well as phosphorylation of its target, acetyl-CoA-carboxylase. AMPK was strongly affected already at 2 microM DXR, even before substantial cardiac dysfunction occurred. Impairment of CK isoenzymes was mostly moderate but became significant at 20 microM DXR. Only at 2 microM DXR did upregulation of brain-type CK compensate for inactivation of other isoenzymes. These results suggest that an impairment of kinase systems regulating cellular energy homeostasis is involved in the development of DXR cardiotoxicity.
authors.affiliation: Institute of Cell Biology, Swiss Federal Institute of Technology, Hönggerberg HPM F23, CH-8093 Zürich, Switzerland. schlattn@cell.biol.ethz.ch
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Tokarska-Schlattner
authors.forename: Michael
authors.initials: M
authors.lastname: Zaugg
authors.forename: Rafaela
authors.initials: R
authors.lastname: da Silva
authors.forename: Eliana
authors.initials: E
authors.lastname: Lucchinetti
authors.forename: Marcus C
authors.initials: MC
authors.lastname: Schaub
authors.forename: Theo
authors.initials: T
authors.lastname: Wallimann
authors.forename: Uwe
authors.initials: U
authors.lastname: Schlattner
mesh_terms: D055372:AMP-Activated Protein Kinases; D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000633:toxicity*; D002467:Cell Nucleus / Q000378:metabolism; D003402:Creatine Kinase / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism; D045304:Cytochromes c / Q000037:antagonists & inhibitors / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004317:Doxorubicin / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000633:toxicity*; D004734:Energy Metabolism / Q000187:drug effects*; D004795:Enzyme Stability; D006321:Heart / Q000187:drug effects* / Q000503:physiopathology; D066298:In Vitro Techniques; D007425:Intracellular Membranes / Q000378:metabolism; D007527:Isoenzymes / Q000378:metabolism; D008297:Male; D008929:Mitochondria, Heart / Q000378:metabolism; D009097:Multienzyme Complexes / Q000378:metabolism; D009206:Myocardium / Q000201:enzymology / Q000378:metabolism*; D010770:Phosphotransferases / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012518:Sarcomeres / Q000187:drug effects / Q000648:ultrastructure; D015398:Signal Transduction / Q000187:drug effects; D014018:Tissue Distribution
chemical_list: D000903:Antibiotics, Antineoplastic; D007527:Isoenzymes; D009097:Multienzyme Complexes; D004317:Doxorubicin; D045304:Cytochromes c; D010770:Phosphotransferases; D017346:Protein Serine-Threonine Kinases; D055372:AMP-Activated Protein Kinases; D003402:Creatine Kinase