title: Prior starvation mitigates acute doxorubicin cardiotoxicity through restoration of autophagy in affected cardiomyocytes.
abstract: OBJECTIVE
  Active autophagy has recently been reported in doxorubicin-induced cardiotoxicity; here we investigated its pathophysiological role.
  
  
  RESULTS
  Acute cardiotoxicity was induced in green fluorescent protein-microtubule-associated protein 1 light chain 3 (GFP-LC3) transgenic mice by administering two intraperitoneal injections of 10 mg/kg doxorubicin with a 3 day interval. A starvation group was deprived of food for 48 h before each injection to induce autophagy in advance. Doxorubicin treatment caused left ventricular dilatation and dysfunction within 6 days. Cardiomyocyte autophagy appeared to be activated in the doxorubicin group, based on LC3, p62, and cathepsin D expression, while it seemed somewhat diminished by starvation prior to doxorubicin treatment. Unexpectedly, however, myocardial ATP levels were reduced in the doxorubicin group, and this reduction was prevented by earlier starvation. Electron microscopy revealed that the autophagic process was indeed initiated in the doxorubicin group, as shown by the increased lysosomes, but was not completed, i.e. autophagolysosome formation was rare. Starvation prior to doxorubicin treatment partly restored autophagosome formation towards control levels. Autophagic flux assays in both in vivo and in vitro models confirmed that doxorubicin impairs completion of the autophagic process in cardiomyocytes. The activities of both AMP-activated protein kinase and the autophagy-initiating kinase unc-51-like kinase 1 (ULK1) were found to be decreased by doxorubicin, and these were restored by prior starvation.
  
  
  CONCLUSIONS
  Prior starvation mitigates acute doxorubicin cardiotoxicity; the underlying mechanism may be, at least in part, restoration and further augmentation of myocardial autophagy, which is impaired by doxorubicin, probably through inactivation of AMP-activated protein kinase and ULK1.
authors.affiliation: Department of Cardiology,  Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu 501-1194,  Japan.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Kawaguchi
authors.forename: Genzou
authors.initials: G
authors.lastname: Takemura
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Kanamori
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Takeyama
authors.forename: Takatomo
authors.initials: T
authors.lastname: Watanabe
authors.forename: Kentaro
authors.initials: K
authors.lastname: Morishita
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ogino
authors.forename: Akiko
authors.initials: A
authors.lastname: Tsujimoto
authors.forename: Kazuko
authors.initials: K
authors.lastname: Goto
authors.forename: Rumi
authors.initials: R
authors.lastname: Maruyama
authors.forename: Masanori
authors.initials: M
authors.lastname: Kawasaki
authors.forename: Atsushi
authors.initials: A
authors.lastname: Mikami
authors.forename: Takako
authors.initials: T
authors.lastname: Fujiwara
authors.forename: Hisayoshi
authors.initials: H
authors.lastname: Fujiwara
authors.forename: Shinya
authors.initials: S
authors.lastname: Minatoguchi
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D000903:Antibiotics, Antineoplastic; D001343:Autophagy / Q000187:drug effects*; D000071189:Autophagy-Related Protein-1 Homolog; D002402:Cathepsin D / Q000378:metabolism; D002478:Cells, Cultured; D004317:Doxorubicin; D004734:Energy Metabolism; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006333:Heart Failure / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*; D017379:Hypertrophy, Left Ventricular / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*; D051379:Mice; D008822:Mice, Transgenic; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D032383:Myocytes, Cardiac / Q000378:metabolism / Q000473:pathology*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D051381:Rats; D013217:Starvation / Q000150:complications* / Q000378:metabolism; D013318:Stroke Volume; D013997:Time Factors; D018487:Ventricular Dysfunction, Left / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*; D016277:Ventricular Function, Left; D017725:Ventricular Pressure
chemical_list: D055372:AMP-Activated Protein Kinases; D000255:Adenosine Triphosphate; D000903:Antibiotics, Antineoplastic; D000071189:Autophagy-Related Protein-1 Homolog; D002402:Cathepsin D; D004317:Doxorubicin; D049452:Green Fluorescent Proteins; D008869:Microtubule-Associated Proteins; D017346:Protein Serine-Threonine Kinases; C526109:Anxa3 protein, rat; C112444:Ulk1 protein, mouse; C533923:Ctsd protein, mouse