title: Apoptotic cell death is initiated during normothermic ischemia in human kidneys.
abstract: Ischemic damage plays an important role in post-transplant organ failure. Activation of the apoptotic cascade is crucially involved in post-ischemic inflammation resulting in tissue damage and organ dysfunction. Here we investigate the initiation of the apoptotic cascade during normothermic ischemia in human kidneys using a model for normothermic ischemia with kidneys nephrectomized because of renal cell carcinoma. Ex vivo, kidneys were stored at 37 degrees C, and consecutive biopsies were taken from disease-free tissue. Pro- and anti-apoptotic proteins were assessed by Western blotting and immunofluorescence. During normothermic ischemia the pro-apoptotic proteins Bax and activated caspase-9 increased with ischemia time, whereas caspase-8 was not activated. The anti-apoptotic proteins Bcl-2 and cFLIP decreased in time. Data on Bcl-2 and Bax were supported by immunofluorescence for Bcl-2 and activated Bax. However, activation of the central effector caspase-3, essential for execution of the apoptotic process, was not detected. In conclusion, during normothermic ischemia the apoptotic cascade in the human kidney is initiated, but not fulfilled. Our data show that the duration of ischemia significantly correlates with activation of the apoptotic cascade. These findings provide insight in the initiation of apoptotic cell-death during warm ischemia and may be useful in the assessment of ischemic injury.
authors.affiliation: Department of General Surgery, Nutrition and Toxicology Research Institute Maastricht, Maastricht University, Maastricht, the Netherlands.
authors.forename: Tim G A M
authors.initials: TG
authors.lastname: Wolfs
authors.forename: Bart
authors.initials: B
authors.lastname: de Vries
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Walter
authors.forename: Carine J
authors.initials: CJ
authors.lastname: Peutz-Kootstra
authors.forename: L W Ernest
authors.initials: LW
authors.lastname: van Heurn
authors.forename: Gosse O N
authors.initials: GO
authors.lastname: Oosterhof
authors.forename: Wim A
authors.initials: WA
authors.lastname: Buurman
mesh_terms: D017209:Apoptosis; D015153:Blotting, Western; D053446:CASP8 and FADD-Like Apoptosis Regulating Protein; D002292:Carcinoma, Renal Cell / Q000473:pathology; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases / Q000378:metabolism; D004789:Enzyme Activation; D006358:Hot Temperature; D006801:Humans; D007150:Immunohistochemistry; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D007511:Ischemia / Q000378:metabolism; D007668:Kidney / Q000473:pathology*; D007680:Kidney Neoplasms / Q000473:pathology; D008856:Microscopy, Fluorescence; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D013997:Time Factors; D051028:bcl-2-Associated X Protein
chemical_list: C494826:BAX protein, human; D053446:CASP8 and FADD-Like Apoptosis Regulating Protein; C506386:CFLAR protein, human; D047908:Intracellular Signaling Peptides and Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; C505407:CASP3 protein, human; C505530:CASP8 protein, human; C506433:CASP9 protein, human; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases