Nrf2 deficiency exaggerates doxorubicin-induced cardiotoxicity and cardiac dysfunction

Oxid Med Cell Longev. 2014:2014:748524. doi: 10.1155/2014/748524. Epub 2014 May 6.

Abstract

The anticancer therapy of doxorubicin (Dox) has been limited by its acute and chronic cardiotoxicity. In addition to a causative role of oxidative stress, autophagy appears to play an important role in the regulation of Dox-induced cardiotoxicity. However, the underlying mechanisms remain unclear. Accordingly, we explored a role of nuclear factor erythroid-2 related factor 2 (Nrf2) in Dox-induced cardiomyopathy with a focus on myocardial oxidative stress and autophagic activity. In wild type (WT) mice, a single intraperitoneal injection of 25 mg/kg Dox rapidly induced cardiomyocyte necrosis and cardiac dysfunction, which were associated with oxidative stress, impaired autophagy, and accumulated polyubiquitinated protein aggregates. However, these Dox-induced adverse effects were exaggerated in Nrf2 knockout (Nrf2(-/-)) mice. In cultured cardiomyocytes, overexpression of Nrf2 increased the steady levels of LC3-II, ameliorated Dox-induced impairment of autophagic flux and accumulation of ubiquitinated protein aggregates, and suppressed Dox-induced cytotoxicity, whereas knockdown of Nrf2 exerted opposite effects. Moreover, the exaggerated adverse effects in Dox-intoxicated Nrf2 depleted cardiomyocytes were dramatically attenuated by forced activation of autophagy via overexpression of autophagy related gene 5 (Atg5). Thus, these results suggest that Nrf2 is likely an endogenous suppressor of Dox-induced cardiotoxicity by controlling both oxidative stress and autophagy in the heart.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autophagy / drug effects
  • Autophagy-Related Protein 5
  • Cardiomyopathies / chemically induced
  • Cardiomyopathies / metabolism
  • Cardiomyopathies / pathology
  • Cardiotoxicity
  • Cells, Cultured
  • Doxorubicin / toxicity*
  • Heart / drug effects
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Microtubule-Associated Proteins / metabolism
  • Myocardium / metabolism
  • Myocytes, Cardiac / drug effects*
  • Myocytes, Cardiac / metabolism
  • NF-E2-Related Factor 2 / antagonists & inhibitors
  • NF-E2-Related Factor 2 / genetics
  • NF-E2-Related Factor 2 / metabolism*
  • Necrosis
  • Oxidative Stress / drug effects

Substances

  • Atg5 protein, mouse
  • Autophagy-Related Protein 5
  • Microtubule-Associated Proteins
  • NF-E2-Related Factor 2
  • Nfe2l2 protein, mouse
  • Doxorubicin