The successful use of
anthracyclines like
doxorubicin in
chemotherapy is limited by their severe
cardiotoxicity. Despite decades of clinical application, a satisfying description of the molecular mechanisms involved and a preventive treatment have not yet been achieved. Here we address
doxorubicin-induced changes in cell signaling as a novel potential mediator of
doxorubicin toxicity by applying a non-biased screen of the cardiac phosphoproteome. Two-dimensional gel electrophoresis, phosphospecific staining, quantitative image analysis, and MALDI-TOF/TOF mass spectrometry were combined to identify (de)phosphorylation events occurring in the isolated rat heart upon Langendorff-perfusion with clinically relevant (5 μM) and supraclinical concentrations (25 μM) of
doxorubicin. This approach identified 22
proteins with a significantly changed phosphorylation status and these results were validated by immunoblotting for selected phosphosites. Overrepresentation of
mitochondrial proteins (>40%) identified this compartment as a prime target of
doxorubicin. Identified
proteins were mainly involved in energy metabolism (e.g.
pyruvate dehydrogenase and
acyl-CoA dehydrogenase), sarcomere structure and function (e.g.
desmin) or chaperone-like activities (e.g. α-
crystallin B chain and
prohibitin). Changes in phosphorylation of
pyruvate dehydrogenase, regulating
pyruvate entry into the Krebs cycle, and
desmin, maintaining myofibrillar array, are relevant for main symptoms of cardiac dysfunction related to
doxorubicin treatment, namely energy imbalance and myofibrillar disorganization. This article is part of a Special Issue entitled: Translational Proteomics.