Enhanced development of caspase-independent cortical cell death during cold storage in kidneys of non-heart-beating donors.
BACKGROUND
Understanding the mechanisms of injury associated with cardiac arrest is essential for defining strategies aimed at improving preservation and function of kidneys harvested in non-heart-beating (NHB) donors.


METHODS
We standardized a model of NHB donors in rats and studied the kinetics and types (apoptosis vs. necrosis) of renal cell death developing during cold storage. Using quantitative polymerase chain reaction, immunoblotting, and caspase inhibition, we also studied the molecular pathways regulating renal cell death in this model.


RESULTS
The kinetics and extent of cell death developing in cortical tubules during cold storage were found to be increased in non-heart-beating (NHB) kidneys. Apoptosis of cortical tubules predominated in NHB kidneys exposed to 10 hr of cold storage, whereas necrosis increased after longer periods of cold ischemia. Shortly after cardiac arrest, a rapid up-regulation of Bax and Hsp 70 was found at the protein level in NHB kidneys. After 24 hr of cold storage, induction of Bax was maintained, whereas protein levels of Hsp70 returned to levels comparable to heart-beating (HB) controls. Also, mRNA levels of Bax were found to increase during cold storage in NHB kidneys. Cortical cell death was found to be largely caspase-independent but responsive to hydroxyl-radical scavenging with dimethyl sulfoxide (DMSO).


CONCLUSIONS
Cardiac arrest promotes activation of death-inducing molecules such as Bax and is associated with increased development of caspase-independent renal cell death during cold storage. Developing strategies, such as free radical scavenging, aimed at inhibiting cell death during cold storage, could prove useful for improving preservation of NHB kidneys.
Bellemare
Sarah
S
CHUM-Research Centre, University of Montreal, 1560 Sherbrooke Est, Montreal, Quebec H2L 4M1, Canada.
Vigneault
Normand
N
Madore
François
F
Raymond
Marc-André
MA
Cailhier
Jean-François
JF
Hébert
Marie-Josée
MJ
D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D000818:Animals; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism; D016923:Cell Death / Q000502:physiology*; D003080:Cold Temperature; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics; D006323:Heart Arrest; D007511:Ischemia / Q000473:pathology; D007672:Kidney Cortex / Q000473:pathology* / Q000502:physiology; D016030:Kidney Transplantation; D008297:Male; D009336:Necrosis; D011518:Proto-Oncogene Proteins / Q000235:genetics; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics; D051381:Rats; D011916:Rats, Inbred F344; D016159:Tumor Suppressor Protein p53 / Q000235:genetics; D051028:bcl-2-Associated X Protein; D051020:bcl-X Protein
D000590:Amino Acid Chloromethyl Ketones; C494828:Bax protein, rat; C494813:Bcl2l1 protein, rat; D061945:Caspase Inhibitors; D015853:Cysteine Proteinase Inhibitors; D018840:HSP70 Heat-Shock Proteins; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D016159:Tumor Suppressor Protein p53; D051028:bcl-2-Associated X Protein; D051020:bcl-X Protein; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; D020169:Caspases