Daunorubicin therapy is associated with upregulation of E3 ubiquitin ligases in the heart

Exp Biol Med (Maywood). 2012 Feb;237(2):219-26. doi: 10.1258/ebm.2011.011106. Epub 2012 Feb 10.

Abstract

Daunorubicin (DNR) and doxorubicin (DOX) are two of the most effective anthracycline drugs known for the treatment of systemic neoplasms and solid tumors. However, their clinical use is hampered due to profound cardiotoxicity. The mechanism by which DNR injures the heart remains to be fully elucidated. Recent reports have indicated that DOX activates ubiquitin proteasome-mediated degradation of specific transcription factors; however, no reports exist on the effect of DNR on the E3 ubiquitin ligases, MURF-1 (muscle ring finger 1) and MAFbx (muscle atrophy F-box). The aim of this study was to investigate the effect of DNR treatment on the protein and organelle degradation systems in the heart and to elucidate some of the signalling mechanisms involved. Adult rats were divided into two groups where one group received six intraperitoneal injections of 2 mg/kg DNR on alternate days and the other group received saline injections as control. Hearts were excised and perfused on a working heart system the day after the last injection and freeze-clamped for biochemical analysis. DNR treatment significantly attenuated cardiac function and increased apoptosis in the heart. DNR-induced cardiac cytotoxicity was associated with upregulation of the E3 ligases, MURF-1 and MAFbx and also caused significant increases in two markers of autophagy, beclin-1 and LC3. These changes observed in the heart were also associated with attenuation of the phosphoinositide 3-kinase/Akt signalling pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibiotics, Antineoplastic / pharmacology
  • Apoptosis
  • Apoptosis Regulatory Proteins / biosynthesis
  • Beclin-1
  • Caspase 3 / metabolism
  • Daunorubicin / pharmacology*
  • Gene Expression Regulation, Enzymologic*
  • Male
  • Microtubule-Associated Proteins / biosynthesis
  • Muscle Proteins / metabolism
  • Myocardium / enzymology*
  • Phosphatidylinositol 3-Kinases / metabolism
  • Proteasome Endopeptidase Complex / metabolism
  • Rats
  • Rats, Wistar
  • SKP Cullin F-Box Protein Ligases / metabolism
  • Signal Transduction
  • Tripartite Motif Proteins
  • Ubiquitin / metabolism
  • Ubiquitin-Protein Ligases / metabolism*

Substances

  • Antibiotics, Antineoplastic
  • Apoptosis Regulatory Proteins
  • Beclin-1
  • Becn1 protein, rat
  • LC3 protein, rat
  • Microtubule-Associated Proteins
  • Muscle Proteins
  • Tripartite Motif Proteins
  • Ubiquitin
  • Fbxo32 protein, rat
  • SKP Cullin F-Box Protein Ligases
  • Trim63 protein, rat
  • Ubiquitin-Protein Ligases
  • Phosphatidylinositol 3-Kinases
  • Caspase 3
  • Proteasome Endopeptidase Complex
  • Daunorubicin