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Ischemic preconditioning of the murine liver protects through the Akt kinase pathway
Author(s) -
Izuishi Kunihiko,
Tsung Allan,
Hossain Mohammad Akram,
Fujiwara Masao,
Wakabayashi Hisao,
Masaki Tsutomu,
Billiar Timothy R.,
Maeta Hajime
Publication year - 2006
Publication title -
hepatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.488
H-Index - 361
eISSN - 1527-3350
pISSN - 0270-9139
DOI - 10.1002/hep.21298
Subject(s) - protein kinase b , ischemic preconditioning , medicine , kinase , pi3k/akt/mtor pathway , reperfusion injury , ischemia , liver injury , pharmacology , gsk 3 , liver transplantation , phosphorylation , endocrinology , apoptosis , transplantation , chemistry , biology , microbiology and biotechnology , biochemistry
Hepatic ischemia-reperfusion (I/R) injury occurs in the settings of transplantation, trauma, and elective liver resection. Ischemic preconditioning has been used as a strategy to reduce inflammation and organ damage from I/R of the liver. However, the mechanisms involved in this process are poorly understood. We examined the role of the phosphatidylinositol 3 (PI3) kinase/Akt-signaling pathway during hepatic ischemic preconditioning (IPC). Prior to a prolonged warm ischemic insult, BALB/c mice were subjected to a 20-minute IPC period consisting of 10 minutes of ischemia and 10 minutes of reperfusion. Mice undergoing IPC demonstrated a significantly greater level and earlier activation of Akt in the liver compared with control animals. IPC also resulted in markedly less hepatocellular injury and improved survival compared with control animals. Akt activation associated with hepatic IPC suppressed the activity of several modulators of apoptosis, including Bad, glycogen synthase kinase beta, and caspase-3. In addition, IPC also inhibited the activities of c-Jun N-terminal kinase and nuclear factor kappaB after I/R. Pretreatment of mice with PI3 kinase inhibitors completely abolished Akt phosphorylation and the protective effects seen with IPC. In conclusion, these results indicate that the PI3 kinase/Akt pathway plays an essential role in the protective effects of IPC in hepatic I/R injury. Modulation of this pathway may be a potential strategy in clinical settings of ischemic liver injury to decrease organ damage.