title: Ubiquitin-proteasome system inhibitors and AMPK regulation in hepatic cold ischaemia and reperfusion injury: possible mechanisms.
abstract: In the present Hypothesis article, we summarize and present data from the literature that support our hypothesis on the potential mechanisms by which UPS (ubiquitin-proteasome system) inhibitors reduce I/R (ischaemia/reperfusion) injury in the liver. I/R is the main cause of primary liver failure and, consequently, minimizing the detrimental effects of this process could increase the number of suitable transplantation grafts and also enhance the survival rate of patients after liver transplantation. A potential strategy to reduce I/R injury is the use of UPS inhibitors either as additives to preservation solutions or as drugs administered to patients. However, there is still controversy over whether the use of UPS inhibitors is beneficial or deleterious with regard to liver injury. From our experience and the few studies that have investigated the role of UPS in hepatic I/R, we believe that the use of UPS inhibitors is a potential strategy to reduce I/R injury in liver transplantation and graft preservation. We hypothesize that one of the main mechanisms of action of UPS inhibitors may be the up-regulation of AMPK (AMP-activated protein kinase) activity and the consequent down-regulation of mTOR (mammalian target of rapamycin), which may finally influence autophagy and preserve the energy state of the cell.
authors.affiliation: Experimental Hepatic Ischemia-Reperfusion Unit, Institut d'Investigacions Biomèdiques de Barcelona-Consejo Superior de Investigaciones Científicas, Barcelona, Spain.
authors.forename: Susagna
authors.initials: S
authors.lastname: Padrissa-Altés
authors.forename: Mohamed Amine
authors.initials: MA
authors.lastname: Zaouali
authors.forename: Ramon
authors.initials: R
authors.lastname: Bartrons
authors.forename: Joan
authors.initials: J
authors.lastname: Roselló-Catafau
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000502:physiology*; D050377:Cold Ischemia; D059865:Endoplasmic Reticulum Stress; D006801:Humans; D008099:Liver / Q000098:blood supply*; D016031:Liver Transplantation; D009569:Nitric Oxide / Q000502:physiology; D061988:Proteasome Inhibitors; D015427:Reperfusion Injury / Q000209:etiology* / Q000517:prevention & control; D025801:Ubiquitin / Q000037:antagonists & inhibitors*
chemical_list: D061988:Proteasome Inhibitors; D025801:Ubiquitin; D009569:Nitric Oxide; D055372:AMP-Activated Protein Kinases