title: The CORM ALF-186 Mediates Anti-Apoptotic Signaling via an Activation of the p38 MAPK after Ischemia and Reperfusion Injury in Retinal Ganglion Cells.
abstract: OBJECTIVE
  Ischemia and reperfusion injury may induce apoptosis and lead to sustained tissue damage and loss of function, especially in neuronal organs. While carbon monoxide is known to exert protective effects after various harmful events, the mechanism of carbon monoxide releasing molecules in neuronal tissue has not been investigated yet. We hypothesize that the carbon monoxide releasing molecule (CORM) ALF-186, administered after neuronal ischemia-reperfusion injury (IRI), counteracts retinal apoptosis and its involved signaling pathways and consecutively reduces neuronal tissue damage.
  
  
  METHODS
  IRI was performed in rat´s retinae for 1 hour. The water-soluble CORM ALF-186 (10 mg/kg) was administered intravenously via a tail vein after reperfusion. After 24 and 48 hours, retinal tissue was harvested to analyze mRNA and protein expression of Bcl-2, Bax, Caspase-3, ERK1/2, p38 and JNK. Densities of fluorogold pre-labeled retinal ganglion cells (RGC) were analyzed 7 days after IRI. Immunohistochemistry was performed on retinal cross sections.
  
  
  RESULTS
  ALF-186 significantly reduced IRI mediated loss of RGC. ALF-186 treatment differentially affected mitogen-activated protein kinases (MAPK) phosphorylation: ALF-186 activated p38 and suppressed ERK1/2 phosphorylation, while JNK remained unchanged. Furthermore, ALF-186 treatment affected mitochondrial apoptosis, decreasing pro-apoptotic Bax and Caspase-3-cleavage, but increasing anti-apoptotic Bcl-2. Inhibition of p38-MAPK using SB203580 reduced ALF-186 mediated anti-apoptotic effects.
  
  
  CONCLUSIONS
  In this study, ALF-186 mediated substantial neuroprotection, affecting intracellular apoptotic signaling, mainly via MAPK p38. CORMs may thus represent a promising therapeutic alternative treating neuronal IRI.
authors.affiliation: Department of Anesthesiology and Critical Care, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: Ulbrich
authors.affiliation: Department of Anesthesiology and Critical Care, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
authors.forename: Kai B
authors.initials: KB
authors.lastname: Kaufmann
authors.affiliation: Department of Anesthesiology and Critical Care, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Meske
authors.affiliation: Eye Center, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
authors.forename: Wolf A
authors.initials: WA
authors.lastname: Lagrèze
authors.affiliation: Eye Center, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Augustynik
authors.affiliation: Department of Anesthesiology and Critical Care, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
authors.forename: Hartmut
authors.initials: H
authors.lastname: Buerkle
authors.affiliation: Instituto de Tecnologia Química e Biológica-António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.|Alfama Ltd., Instituto de Biologia Experimental e Tecnológica, IBET, Oeiras, Portugal.
authors.forename: Carlos C
authors.initials: CC
authors.lastname: Ramao
authors.affiliation: Eye Center, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Biermann
authors.affiliation: Department of Anesthesiology and Critical Care, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
authors.forename: Ulrich
authors.identifier: http://orcid.org/0000-0002-9991-3226
authors.initials: U
authors.lastname: Goebel
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D056831:Coordination Complexes / Q000737:chemistry / Q000494:pharmacology*; D004195:Disease Models, Animal; D005260:Female; D007093:Imidazoles / Q000494:pharmacology; D008297:Male; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D018696:Neuroprotective Agents / Q000494:pharmacology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism; D011725:Pyridines / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000378:metabolism / Q000473:pathology*; D012165:Retinal Ganglion Cells / Q000166:cytology / Q000378:metabolism / Q000473:pathology; D015398:Signal Transduction / Q000187:drug effects*; D051028:bcl-2-Associated X Protein / Q000235:genetics / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D056831:Coordination Complexes; D007093:Imidazoles; D018696:Neuroprotective Agents; D019253:Proto-Oncogene Proteins c-bcl-2; D011725:Pyridines; D012333:RNA, Messenger; D051028:bcl-2-Associated X Protein; C000620213:triscarbonyl(histidinato)molybdate(III); D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D048051:p38 Mitogen-Activated Protein Kinases; D053148:Caspase 3; C093642:SB 203580