title: Role of perfusion medium, oxygen and rheology for endoplasmic reticulum stress-induced cell death after hypothermic machine preservation of the liver.
abstract: Recently, the endoplasmic reticulum (ER) has been disclosed as subcellular target reactive to ischaemia/reperfusion and possibly influenced by hypothermic machine preservation. Here, the respective role of perfusate, perfusion itself, and the effect of continuous oxygenation to trigger ER-stress in the graft should be investigated. Livers were retrieved 30 min after cardiac arrest of male Wistar rats and preserved by cold storage (CS) in histidine-tryptophan-ketoglutarate (HTK) for 18 h at 4 degrees C. Other organs were subjected to aerobic conditions either by oxygenated machine perfusion with HTK (MP-HTK) or Belzer solution (MP-Belzer) at 4 degrees C or by venous insufflation of gaseous oxygen during cold storage (VSOP). Viability of livers was evaluated upon reperfusion in vitro according to previously validated techniques for 120 min at 37 degrees C. Oxygenation during preservation (MP-HTK, MP-Belzer or VSOP) concordantly improved functional recovery (bile flow, ammonia clearance), reduced parenchymal enzyme leakage and histological signs of necrosis and significantly attenuated mitochondrial induction of apoptosis (cleavage of caspase 9) compared to CS. However, MP with either medium produced about 500% elevated protein expression of CHOP/GADD153, suggesting pro-apoptotic ER-stress responses, paralleled by a significant elevation of caspase-12 enzyme activity compared to CS or VSOP. Although MP also promoted a slight (20%) induction of the cytoprotective ER-protein Bax inhibitor protein (BI-1), prevailing of proapoptotic reactions was seen by increased cleavage of caspase-3 and poly (ADP-Ribase)-polymerase (PARP) in both MP-groups. Endoplasmic stress activation is conjectured a specific side effect of long-term machine preservation irrespective of the medium, actually promoting cellular apoptosis via activation of caspase-12. The simple insufflation of gaseous O2 may be considered a feasible alternative, apparently indifferent to the endoplasmic reticulum.
authors.affiliation: Surgical Research Division, University Clinic of Surgery, Bonn, Germany.
authors.forename: Steffen
authors.initials: S
authors.lastname: Manekeller
authors.forename: Andrea
authors.initials: A
authors.lastname: Schuppius
authors.forename: Judith
authors.initials: J
authors.lastname: Stegemann
authors.forename: Andreas
authors.initials: A
authors.lastname: Hirner
authors.forename: Thomas
authors.initials: T
authors.lastname: Minor
mesh_terms: D000241:Adenosine; D000332:Aerobiosis; D000493:Allopurinol; D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D053454:Caspase 12 / Q000378:metabolism; D015925:Cryopreservation; D004721:Endoplasmic Reticulum / Q000473:pathology*; D005947:Glucose; D005978:Glutathione; D007328:Insulin; D008099:Liver / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D008297:Male; D008353:Mannitol; D008565:Membrane Proteins / Q000378:metabolism; D008930:Mitochondria, Liver / Q000502:physiology*; D009926:Organ Preservation; D019188:Organ Preservation Solutions; D010101:Oxygen Consumption; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D011189:Potassium Chloride; D011343:Procaine; D011887:Raffinose; D051381:Rats; D017208:Rats, Wistar; D051742:Transcription Factor CHOP / Q000378:metabolism
chemical_list: D051017:Apoptosis Regulatory Proteins; C039984:Bretschneider cardioplegic solution; D007328:Insulin; D008565:Membrane Proteins; D019188:Organ Preservation Solutions; C484209:TMBIM6 protein, human; C055206:University of Wisconsin-lactobionate solution; D051742:Transcription Factor CHOP; D008353:Mannitol; D011343:Procaine; D000493:Allopurinol; D011189:Potassium Chloride; D011065:Poly(ADP-ribose) Polymerases; D053454:Caspase 12; D005978:Glutathione; D005947:Glucose; D000241:Adenosine; D011887:Raffinose