Doxorubicin-induced expression of LOX-1 in H9c2 cardiac muscle cells and its role in apoptosis

Biochem Biophys Res Commun. 2005 Sep 16;335(1):188-96. doi: 10.1016/j.bbrc.2005.07.064.

Abstract

Up-regulation of LOX-1 is implicated in apoptosis in both vascular smooth muscle cells and in endothelial cells. We examined the effects of doxorubicin on LOX-1 expression in H9c2 cardiomyocytes and the role played by LOX-1 up-regulation in doxorubicin-induced apoptosis. Reactive oxygen species (ROS) formation was assessed by DCF flow cytometry. LOX-1 mRNA and protein expression was assessed by RT-PCR and Western blotting. Apoptosis was evaluated by flow cytometry with annexin/PI double staining. Doxorubicin-induced LOX-1 expression in a concentration- and time-dependent fashion. The doxorubicin-induced ROS formation and the LOX-1 expression were significantly attenuated by pre-treatment with antioxidants. By exposing cells that had been pre-treated with doxorubicin to oxidized-LDL, a LOX-1 agonist, in the presence or in the absence of k-carrageenan, a LOX-1 receptor antagonist, we documented that doxorubicin-induced LOX-1 expression plays a role in inducing apoptosis. These findings suggest that LOX-1 up-regulation is redox-sensitive and may contribute to doxorubicin-induced cardiotoxicity.

MeSH terms

  • Acetylcysteine / pharmacology
  • Animals
  • Apoptosis / drug effects*
  • Atenolol / pharmacology
  • Carbazoles / pharmacology
  • Carvedilol
  • Cell Line
  • Doxorubicin / pharmacology*
  • Flow Cytometry
  • Free Radicals / metabolism
  • Hydrogen Peroxide / metabolism
  • Hydrogen Peroxide / pharmacology
  • Myocytes, Cardiac / cytology
  • Myocytes, Cardiac / drug effects*
  • Myocytes, Cardiac / metabolism*
  • Propanolamines / pharmacology
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Rats
  • Razoxane / pharmacology
  • Receptors, LDL / genetics
  • Receptors, LDL / metabolism*
  • Receptors, Oxidized LDL
  • Scavenger Receptors, Class E
  • Up-Regulation / drug effects

Substances

  • Carbazoles
  • Free Radicals
  • OLR1 protein, rat
  • Propanolamines
  • RNA, Messenger
  • Receptors, LDL
  • Receptors, Oxidized LDL
  • Scavenger Receptors, Class E
  • Carvedilol
  • Atenolol
  • Razoxane
  • Doxorubicin
  • Hydrogen Peroxide
  • Acetylcysteine