title: Levosimendan inhibits peroxidation in hepatocytes by modulating apoptosis/autophagy interplay.
abstract: BACKGROUND
  Levosimendan protects rat liver against peroxidative injuries through mechanisms related to nitric oxide (NO) production and mitochondrial ATP-dependent K (mitoKATP) channels opening. However, whether levosimendan could modulate the cross-talk between apoptosis and autophagy in the liver is still a matter of debate. Thus, the aim of this study was to examine the role of levosimendan as a modulator of the apoptosis/autophagy interplay in liver cells subjected to peroxidation and the related involvement of NO and mitoKATP.
  
  
  RESULTS
  In primary rat hepatocytes that have been subjected to oxidative stress, Western blot was performed to examine endothelial and inducible NO synthase isoforms (eNOS, iNOS) activation, apoptosis/autophagy and survival signalling detection in response to levosimendan. In addition, NO release, cell viability, mitochondrial membrane potential and mitochondrial permeability transition pore opening (MPTP) were examined through specific dyes. Some of those evaluations were also performed in human hepatic stellate cells (HSC). Pre-treatment of hepatocytes with levosimendan dose-dependently counteracted the injuries caused by oxidative stress and reduced NO release by modulating eNOS/iNOS activation. In hepatocytes, while the autophagic inhibition reduced the effects of levosimendan, after the pan-caspases inhibition, cell survival and autophagy in response to levosimendan were increased. Finally, all protective effects were prevented by both mitoKATP channels inhibition and NOS blocking. In HSC, levosimendan was able to modulate the oxidative balance and inhibit autophagy without improving cell viability and apoptosis.
  
  
  CONCLUSIONS
  Levosimendan protects hepatocytes against oxidative injuries by autophagic-dependent inhibition of apoptosis and the activation of survival signalling. Such effects would involve mitoKATP channels opening and the modulation of NO release by the different NOS isoforms. In HSC, levosimendan would also play a role in cell activation and possible evolution toward fibrosis. These findings highlight the potential of levosimendan as a therapeutic agent for the treatment or prevention of liver ischemia/reperfusion injuries.
authors.affiliation: Laboratory of Physiology and Experimental Surgery, Department of Translational Medicine, University Eastern Piedmont "Amedeo Avogadro", Via Solaroli 17, Azienda Ospedaliera Universitaria Maggiore della Carità, corso Mazzini 36, Novara, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Grossini
authors.affiliation: Laboratory of Physiology and Experimental Surgery, Department of Translational Medicine, University Eastern Piedmont "Amedeo Avogadro", Via Solaroli 17, Azienda Ospedaliera Universitaria Maggiore della Carità, corso Mazzini 36, Novara, Italy.
authors.forename: Kevin
authors.initials: K
authors.lastname: Bellofatto
authors.affiliation: Laboratory of Physiology and Experimental Surgery, Department of Translational Medicine, University Eastern Piedmont "Amedeo Avogadro", Via Solaroli 17, Azienda Ospedaliera Universitaria Maggiore della Carità, corso Mazzini 36, Novara, Italy.
authors.forename: Serena
authors.initials: S
authors.lastname: Farruggio
authors.affiliation: Laboratory of Physiology and Experimental Surgery, Department of Translational Medicine, University Eastern Piedmont "Amedeo Avogadro", Via Solaroli 17, Azienda Ospedaliera Universitaria Maggiore della Carità, corso Mazzini 36, Novara, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Sigaudo
authors.affiliation: Laboratory of Physiology and Experimental Surgery, Department of Translational Medicine, University Eastern Piedmont "Amedeo Avogadro", Via Solaroli 17, Azienda Ospedaliera Universitaria Maggiore della Carità, corso Mazzini 36, Novara, Italy.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Marotta
authors.affiliation: Laboratory of Physiology and Experimental Surgery, Department of Translational Medicine, University Eastern Piedmont "Amedeo Avogadro", Via Solaroli 17, Azienda Ospedaliera Universitaria Maggiore della Carità, corso Mazzini 36, Novara, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Raina
authors.affiliation: Laboratory of Physiology and Experimental Surgery, Department of Translational Medicine, University Eastern Piedmont "Amedeo Avogadro", Via Solaroli 17, Azienda Ospedaliera Universitaria Maggiore della Carità, corso Mazzini 36, Novara, Italy.
authors.forename: Veronica
authors.initials: V
authors.lastname: De Giuli
authors.affiliation: Laboratory of Physiology and Experimental Surgery, Department of Translational Medicine, University Eastern Piedmont "Amedeo Avogadro", Via Solaroli 17, Azienda Ospedaliera Universitaria Maggiore della Carità, corso Mazzini 36, Novara, Italy.
authors.forename: David
authors.initials: D
authors.lastname: Mary
authors.affiliation: Laboratory of Physiology and Experimental Surgery, Department of Translational Medicine, University Eastern Piedmont "Amedeo Avogadro", Via Solaroli 17, Azienda Ospedaliera Universitaria Maggiore della Carità, corso Mazzini 36, Novara, Italy.
authors.forename: Piero
authors.initials: P
authors.lastname: Pollesello
authors.affiliation: Internal Medicine, Department of Translational Medicine, University Eastern Piedmont "Amedeo Avogadro", Via Solaroli 17, Azienda Ospedaliera Universitaria Maggiore della Carità, corso Mazzini 36, Novara, Italy.
authors.forename: Rosalba
authors.initials: R
authors.lastname: Minisini
authors.affiliation: Internal Medicine, Department of Translational Medicine, University Eastern Piedmont "Amedeo Avogadro", Via Solaroli 17, Azienda Ospedaliera Universitaria Maggiore della Carità, corso Mazzini 36, Novara, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Pirisi
authors.affiliation: Laboratory of Physiology and Experimental Surgery, Department of Translational Medicine, University Eastern Piedmont "Amedeo Avogadro", Via Solaroli 17, Azienda Ospedaliera Universitaria Maggiore della Carità, corso Mazzini 36, Novara, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Vacca
mesh_terms: D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D001343:Autophagy / Q000187:drug effects*; D015153:Blotting, Western; D022781:Hepatocytes / Q000166:cytology / Q000187:drug effects*; D006801:Humans; D006835:Hydrazones / Q000494:pharmacology*; D015227:Lipid Peroxidation / Q000187:drug effects*; D008297:Male; D033681:Mitochondrial Membrane Transport Proteins / Q000187:drug effects*; D000083162:Mitochondrial Permeability Transition Pore; D009569:Nitric Oxide / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects*; D015221:Potassium Channels / Q000378:metabolism; D011724:Pyridazines / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D000077464:Simendan
chemical_list: D000889:Anti-Arrhythmia Agents; D006835:Hydrazones; D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D015221:Potassium Channels; D011724:Pyridazines; C117780:mitochondrial K(ATP) channel; D009569:Nitric Oxide; D000077464:Simendan; D052247:Nitric Oxide Synthase Type II