title: Neuregulin-1 beta attenuates doxorubicin-induced alterations of excitation-contraction coupling and reduces oxidative stress in adult rat cardiomyocytes.
abstract: Treatment of metastatic breast cancer with doxorubicin (Doxo) in combination with trastuzumab, an antibody targeting the ErbB2 receptor, results in an increased incidence of heart failure. Doxo therapy induces reactive oxygen species (ROS) and alterations of calcium homeostasis. Therefore, we hypothesized that neuregulin-1 beta (NRG), a ligand of the cardiac ErbB receptors, reduces Doxo-induced alterations of EC coupling by triggering antioxidant mechanisms. Adult rat ventricular cardiomyocytes (ARVM) were isolated and treated for 18-48 h. SERCA protein was analyzed by Western blot, EC coupling parameters by fura-2 and video edge detection, gene expression by RT-PCR, and ROS by DCF-fluorescence microscopy. At clinically relevant doses Doxo reduced cardiomyocytes contractility, SERCA protein and SR calcium content. NRG, similarly as the antioxidant N-acetylcystein (NAC), did not affect EC coupling alone, but protected against Doxo-induced damage. NRG and Doxo showed an opposite modulation of glutathione reductase gene expression. NRG, similarly as NAC, reduced peroxide- or Doxo-induced oxidative stress. Specific inhibitors showed, that the antioxidant action of NRG depended on signaling via the ErbB2 receptor and on the Akt- and not on the MAPK-pathway. Therefore, NRG attenuates Doxo-induced alterations of EC coupling and reduces oxidative stress in ARVM. Inhibition of the ErbB2/NRG signaling pathway by trastuzumab in patients concomitantly treated with Doxo might prevent beneficial effects of NRG in the myocardium.
authors.affiliation: Swiss Cardiovascular Center, University Hospital, CH-3010 Bern, Switzerland.
authors.forename: Francesco
authors.initials: F
authors.lastname: Timolati
authors.forename: Daniel
authors.initials: D
authors.lastname: Ott
authors.forename: Laura
authors.initials: L
authors.lastname: Pentassuglia
authors.forename: Marie-Noëlle
authors.initials: MN
authors.lastname: Giraud
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Perriard
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Suter
authors.forename: Christian
authors.initials: C
authors.lastname: Zuppinger
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D004317:Doxorubicin / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects*; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000502:physiology; D020890:Neuregulin-1 / Q000494:pharmacology*; D018384:Oxidative Stress; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D015398:Signal Transduction; D016276:Ventricular Function
chemical_list: D000111:Acetylcysteine; D000903:Antibiotics, Antineoplastic; D002118:Calcium; D004317:Doxorubicin; D006861:Hydrogen Peroxide; D020890:Neuregulin-1; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; D018719:Erb-b2 Receptor Tyrosine Kinases; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; C117467:neuregulin beta