Early stress protein gene expression in a human model of ischemic preconditioning.
Intermittent clamping of the porta hepatis (PHC) is commonly performed during liver surgery to reduce blood loss and has been reported to precondition livers resulting in improved outcome after liver surgery (humans) and transplantation (animals). This study investigated the early expression of cytoprotective stress proteins during ischemia-reperfusion induced by PHC. Liver samples were taken before and after each event in a two-cycle ischemia-reperfusion protocol using 15 minutes of PHC followed by 5 minutes of reperfusion. Liver tissue was analyzed by real-time polymerase chain reaction for heme oxygenase (HO)-1 and heat shock protein (HSP)-70 mRNA expression. Extracted protein was analyzed by Western blot for HO-1, and HSP-70 and nuclear extracts were analyzed by DNA mobility shift assay for hypoxia inducible factor (HIF)-1alpha and heat shock factor (HSF)-1. Within minutes of PHC, significant increases in HO-1 mRNA expression were detected, and these were maintained throughout the protocol (P < 0.01). Protein expression of HO-1 (P < 0.03) and HO-1 activity (P < 0.05) were similarly increased between the start and end of ischemia- reperfusion (40 minutes). Binding of active HIF-1alpha to its consensus sequence was increased within 15 minutes of the start of the ischemia-reperfusion cycle. Although evidence of the transcriptionally active form of HSF-1 was detected at the same time point, this was not reflected in measurable changes in HSP-70 mRNA or protein. In conclusion, expression of the cytoprotective protein HO-1 is significantly up-regulated in the liver within minutes of PHC. It is likely that HO-1 contributes to the early protective effects of ischemic preconditioning.
Patel
Anisha
A
Tissue Injury and Repair Group, MRC Centre for Inflammation Research, Medical School, University of Edinburgh, Edinburgh EH8 9AG, UK.
van de Poll
Marcel C G
MC
Greve
Jan W M
JW
Buurman
Wim A
WA
Fearon
Kenneth C H
KC
McNally
Stephen J
SJ
Harrison
Ewen M
EM
Ross
James A
JA
Garden
O James
OJ
Dejong
Cornelis H C
CH
Wigmore
Stephen J
SJ
D000255:Adenosine Triphosphate / Q000378:metabolism; D000328:Adult; D000368:Aged; D015179:Colorectal Neoplasms / Q000601:surgery; D005260:Female; D005786:Gene Expression Regulation; D005949:Glucose Oxidase / Q000378:metabolism; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics*; D006419:Heme Oxygenase (Decyclizing) / Q000378:metabolism; D051547:Heme Oxygenase-1; D006498:Hepatectomy / Q000379:methods*; D006801:Humans; D007150:Immunohistochemistry; D019194:Ischemic Preconditioning / Q000379:methods*; D007728:Kupffer Cells / Q000201:enzymology; D008111:Liver Function Tests; D008113:Liver Neoplasms / Q000556:secondary / Q000601:surgery; D008297:Male; D008565:Membrane Proteins; D008875:Middle Aged; D008954:Models, Biological; D016133:Polymerase Chain Reaction
D018840:HSP70 Heat-Shock Proteins; D008565:Membrane Proteins; D000255:Adenosine Triphosphate; D005949:Glucose Oxidase; C496541:HMOX1 protein, human; D006419:Heme Oxygenase (Decyclizing); D051547:Heme Oxygenase-1