Sirtuin 1 in rat orthotopic liver transplantation: An IGL-1 preservation solution approach

© The Author(s) 2015. AIM: To investigate the possible involvement of Sirtuin 1 (SIRT1) in rat orthotopic liver transplantation (OLT), when Institute Georges Lopez 1 (IGL-1) preservation solution is enriched with trimetazidine (TMZ). METHODS: Male Sprague-Dawley rats were used as donors and recipients. Livers were stored in IGL-1 preservation solution for 8h at 4 °C, and then underwent OLT according to Kamada's cuff technique without arterialization. In another group, livers were stored in IGL-1 preservation solution supplemented with TMZ, at 10-6 mol/L, for 8 h at 4 °C and then underwent OLT. Rats were sacrificed 24 h after reperfusion, and liver and plasma samples were collected. Liver injury (transaminase levels), mitochondrial damage (glutamate dehydrogenase activity) oxidative stress (malondialdehyde levels), and nicotinamide adenine dinucleotide (NAD+), the co-factor necessary for SIRT1 activity, were determined by biochemical methods. SIRT1 and its substrates (ac-FoxO1, ac-p53), the precursor of NAD+, nicotinamide phosphoribosyltransferase (NAMPT), as well as the phosphorylation of adenosine monophosphate activated protein kinase (AMPK), p-mTOR, p-p70S6K (direct substrate of mTOR), autophagy parameters (beclin-1, LC3B) and MAP kinases (p-p38 and p-ERK) were determined by Western blot. RESULTS: Liver grafts preserved in IGL-1 solution enriched with TMZ presented reduced liver injury and mitochondrial damage compared with those preserved in IGL-1 solution alone. In addition, livers preserved in IGL-1 + TMZ presented reduced levels of oxidative stress. This was consistent with enhanced SIRT1 protein expression and elevated SIRT1 activity, as indicated by decreased acetylation of p53 and FoxO1. The elevated SIRT1 activity in presence of TMZ can be attributed to the enhanced NAMPT protein and NAD+/NADH levels. Up-regulation of SIRT1 was consistent with activation of AMPK and inhibition of phosphorylation of mTOR and its direct substrate (p-p70S6K). As a consequence, autophagy mediators (beclin-1 and LC3B) were overexpressed. Furthermore, MAP kinases were regulated in livers preserved with IGL-1 + TMZ, as they were characterized by enhanced p-ERK and decreased p-p38 protein expression. CONCLUSION: Our study shows that IGL-1 preservation solution enriched with TMZ protects liver grafts from the IRI associated with OLT, through SIRT1 up-regulation.Supported by Fondo de Investigaciones Sanitarias, No. FIS PI12/00519; and Eirini Pantazi is the recipient of a fellowship from AGAUR, No. 2012FI_B00382, Generalitat de Catalunya, Barcelona, Catalonia, Spain.Peer Reviewe

Ischemic preconditioning reduces endoplasmic reticulum stress and upregulates hypoxia inducible factor-1 in ischemic kidney: The role of nitric oxide

Background: Although recent studies indicate that renal ischemic preconditioning (IPC) protects the kidney from ischemia-reperfusion (I/R) injury, the precise protective mechanism remains unclear. In the current study, we investigated whether early IPC could upregulate hypoxia inducible transcription factor-1 (HIF-1) expression and could reduce endoplasmic reticulum (ER) stress after renal I/R and whether pharmacological inhibition of nitric oxide (NO) production would abolish these protective effects. Methods. Kidneys of Wistar rats were subjected to 60 min of warm ischemia followed by 120 min of reperfusion (I/R group), or to 2 preceding cycles of 5 min ischemia and 5 min reperfusion (IPC group), or to intravenously injection of N G-nitro-L- arginine methylester (L-NAME, 5 mg/kg) 5 min before IPC (L-NAME+IPC group). The results of these experimental groups were compared to those of a sham-operated group. Sodium reabsorption rate, creatinine clearance, plasma lactate dehydrogenase (LDH) activity, tissues concentrations of malonedialdehyde (MDA), HIF-1 and nitrite/nitrate were determined. In addition, Western blot analyses were performed to identify the amounts of Akt, endothelial nitric oxide synthase (eNOS) and ER stress parameters. Results: IPC decreased cytolysis, lipid peroxidation and improved renal function. Parallely, IPC enhanced Akt phosphorylation, eNOS, nitrite/nitrate and HIF-1 levels as compared to I/R group. Moreover, our results showed that IPC increased the relative amounts of glucose-regulated protein 78 (GRP78) and decreased those of RNA activated protein kinase (PKR)-like ER kinase (PERK), activating transcription factor 4 (ATF4) and TNF-receptor-associated factor 2 (TRAF2) as judged to I/R group. However, pre treatment with L-NAME abolished these beneficial effects of IPC against renal I/R insults. Conclusion: These findings suggest that early IPC protects kidney against renal I/R injury via reducing oxidative and ER stresses. These effects are associated with phosphorylation of Akt, eNOS activation and NO production contributing thus to HIF-1 stabilization. The beneficial impact of IPC was abolished when NO production is inhibited before IPC application. © 2012 Mahfoudh-Boussaid et al; licensee BioMed Central Ltd.This work was supported by the Tunisian Ministry of Higher Education and Scientific Research and The Spanish Ministry of Foreign Affairs and Cooperation/AECID (A/031197/10).Peer Reviewe

Attenuation of endoplasmic reticulum stress and mitochondrial injury in kidney with ischemic postconditioning application and trimetazidine treatment

This is an Open Access article distributed under the terms of the Creative Commons Attribution License.-- et al.[Background]: Endoplasmic reticulum (ER) and mitochondria have been implicated in the pathology of renal ischemia/reperfusion (I/R). In the present study, we investigated whether the use of ischemic postconditioning (IPostC) and trimetazidine (TMZ) separately or combined could reduce ER stress and mitochondria damage after renal ischemia. [Methods]: Kidneys of Wistar rats were subjected to 60-min of warm ischemia followed by 120-min of reperfusion (I/R group, n = 6), or to 6 cycles of ischemia/reperfusion (10-s each cycle) just after 60-min of warm ischemia (IPostC group, n = 6), or to i.p. injection of TMZ (3 mg/kg) 30-min before ischemia (TMZ group, n = 6), or to the combination of both treatments (IPostC+TMZ group, n = 6). The results of these experimental groups were compared to those of a sham-operated group in which rat renal pedicles were only dissected. Sodium reabsorption rate, creatinine clearance lactate deshydrogenase (LDH) activity in plasma, and concentration of malonedialdehyde (MDA) in tissue were determined. In addition, Western blot analysis was performed to identify the amounts of cytochrome c, c-JunNH2-terminal kinase (JNK), voltage-dependent anion channel (VDAC), glycogen synthase kinase 3-beta (GSK3-β), and ER stress parameters. [Results]: IPostC or/and TMZ significantly decreased cytolysis, oxidative stress and improved renal function in comparison to I/R group. IPostC but not TMZ significantly attenuated ER stress parameters versus I/R group. Indeed, it down-regulated the glucose-regulated protein 78 (GRP78), the activating transcription factor 4 (ATF4), the RNA activated protein kinase (PKR)-like ER kinas (PERK), the X box binding protein-1 (XBP-1) and the caspase12 protein levels. TMZ treatment significantly augmented GSK3-β phosphorylation and reduced levels of cytochrome c and VDAC phosphorylation in comparison to IPostC application. The combination of both treatments gave a synergetic effect. It significantly improved the survival rate, attenuated cytolysis, oxidative stress and improved renal function. [Conclusion]: This study revealed that IPostC protects kidney from I/R injury by suppressing ER stress while the beneficial effects of TMZ are mediated by mitochondria protection. The combination of both treatments ameliorated functional recovery.This work was supported by the Tunisian Ministry of Higher Education and Scientific Research and The Spanish Ministry of Foreign Affairs and Cooperation/ AECID (A/031197/10).Peer Reviewe

Effects of Institut Georges Lopez-1 and Celsior preservation solutions on liver graft injury

To compare Institut Georges Lopez (IGL-1) and Celsior preservation solutions for hepatic endothelium relaxation and liver cold ischemia reperfusion injury (IRI)Tunisian Ministry of Higher Education and Scientific Research, No.UR12ES11Peer reviewe

Role of sirtuins in ischemia-reperfusion injury

Ischemia-reperfusion injury (IRI) remains an unresolved and complicated situation in clinical practice, especially in the case of organ transplantation. Several factors contribute to its complexity; the depletion of energy during ischemia and the induction of oxidative stress during reperfusion initiate a cascade of pathways that lead to cell death and finally to severe organ injury. Recently, the sirtuin family of nicotinamide adenine dinucleotide-dependent deacetylases has gained increasing attention from researchers, due to their involvement in the modulation of a wide variety of cellular functions. There are seven mammalian sirtuins and, among them, the nuclear/cytoplasmic sirtuin 1 (SIRT1) and the mitochondrial sirtuin 3 (SIRT3) are ubiquitously expressed in many tissue types. Sirtuins are known to play major roles in protecting against cellular stress and in controlling metabolic pathways, which are key processes during IRI. In this review, we mainly focus on SIRT1 and SIRT3 and examine their role in modulating pathways against energy depletion during ischemia and their involvement in oxidative stress, apoptosis, microcirculatory stress and inflammation during reperfusion. We present evidence of the beneficial effects of sirtuins against IRI and emphasize the importance of developing new strategies by enhancing their action. © 2013 Baishideng Publishing Group Co., Limited. All rights reservedSupported by AGAUR, No. 2012FI_B00382, Generalitat de Catalunya, Barcelona, Spain, to Pantazi E; CSIC for the development program to Bejaoui M, No. I-COOP0005; The Fondo de Investigaciones Sanitarias, No. FIS PI12/00519Peer reviewe

Trimetazidine and liver preservation against ischaemia-reperfusion injury

Trimetazidine is an anti-ischaemic drug used for angina pectoris treatment. Recently, it has been shown that trimetazidine protects against hepatic ischaemia reperfusion injury. Several hypotheses have been proposed to explain the exact hepatoprotective mechanisms but they still remain unclear. This review assesses the possible mechanisms responsible for the increase of the liver's tolerance against ischaemia-reperfusion injury with special emphasis on: (1) the prevention of oxidative stress and protection of mitochondrial function; (2) the generation of vasoactive mediators such as nitric oxide and endothelins; and finally (3) the preservation of liver energy metabolism. Copyright © 2007 Termedia & Banach.This work was supported by the Ministerio de Educación y Ciencia (project grant SAF 2005-00385), Ministerio de Sanidad y Consumo (project grant PIO60021) and Ministerio de Asuntos Exteriores y de Cooperación Internacional/Agencia Española De Cooperación Internacional.Peer Reviewe

How Institut Georges Lopez preservation solution protects nonsteatotic and steatotic livers against ischemia-reperfusion injury

El pdf es la versión post-print.The Institut Georges Lopez preservation solution (IGL-1) is a serum-free organ preservative that has been shown to protect steatotic livers against hepatic ischemia-reperfusion injury. Although several hypotheses have been proposed to explain the graft protection mechanisms induced by IGL-1 solution, they have not been fully investigated. This review assessed possible IGL-1 mechanisms responsible for the increased liver tolerance of ischemia-reperfusion injury with special emphasis on vasodilatator mediators such as nitric oxide, on oxidative stress prevention, on protection against mitochondrial damage, and finally on induction of cytoprotective factors.This study was supported by the Ministerio de de Sanidad y Consumo (PI 081988), CIBER-ehd, Instituto Carlos III, Madrid and Ministerio de Asuntos Exteriores y de Cooperación Internacionales (A/02987/09 and A/031197/10), Madrid. M.A.Z. is fellowship holder from the Societat Catalana de Trasplantament.Peer Reviewe

Effects of trimetazidine on the Akt/eNOS signaling pathway and oxidative stress in an in vivo rat model of renal ischemia-reperfusion

© 2014 Informa Healthcare USA, Inc. All rights reserved. Renal ischemia reperfusion (I/R) injury, which occurs during renal surgery or transplantation, is the major cause of acute renal failure. Trimetazidine (TMZ), an anti-ischemic drug, protects kidney against the deleterious effects of I/R. However its protective mechanism remains unclear. The aim of this study is to examine the relevance of Akt, endothelial nitric oxide synthase (eNOS), and hypoxia inducible factor-1α (HIF-1α) on TMZ induced protection of kidneys against I/R injury. Wistar rats were subjected to 60 min of warm renal ischemia followed by 120 min of reperfusion, or to intraperitoneal injection of TMZ (3 mg/kg) 30 min before ischemia. In sham operated group renal pedicles were only dissected. Compared to I/R, TMZ treatment decreased lactate dehydrogenase (845 ± 13 vs. 1028 ± 30 U/L). In addition, creatinine clearance and sodium reabsorption rates reached 105 ± 12 versus 31 ± 11 μL/min/g kidney weight and 95 ± 1 versus 68 ± 5%, respectively. Besides, we noted a decrease in malondialdehyde concentration (0.33 ± 0.01 vs. 0.59 ± 0.03 nmol/mg of protein) and an increase in glutathione concentration (2.6 ± 0.2 vs. 0.93 ± 0.16 μg GSH/mg of protein), glutathione peroxidase (95 ± 4 vs. 61 ± 3 μg GSH/min/mg of protein), and superoxide dismutase (25 ± 3 vs. 11 ± 2 U/mg of protein) and catalase (91 ± 12 vs. 38 ± 9 μmol/min/mg of protein) activities. Parallely, we noted a significant increase in p-Akt, eNOS, nitrite and nitrate (18 ± 2 vs. 8 ± 0.1 pomL/mg of protein), HIF-1α (333 ± 48 vs. 177 ± 14 μg/mg of protein) and heme oxygenase-1 (HO-1) levels regarding I/R. TMZ treatment improves renal tolerance to warm I/R. Such protection implicates an activation of Akt/eNOS signaling pathway, HIF-1α stabilization and HO-1 activation.Peer Reviewe

New preservation strategies for preventing liver grafts against cold ischemia reperfusion injury

[Background]: In spite of improvements in University of Wisconsin (UW) preservation solution, the injury from grafts during cold storage is an unresolved problem in liver transplantation. The aim of the present study was to evaluate the beneficial effect on ischemia-reperfusion injury associated with liver transplantation of the inversion of K+ and Na+ concentrations and the replacement of hydroxyethyl starch (HES) by polyethylene glycol (PEG) in UW preservation solution. [Methods]: Using an orthotopic liver transplantation model, the effects on rat liver preservation of a modified preservation solution (UW-PEG) were evaluated, based on the inversion of K+ and Na+ concentration and the replacement of HES by PEG 35 kDa (0.03 mmol/L) in UW preservation solution. [Results]: The use of UW-PEG preservation solution ameliorated the biochemical and histological parameters of hepatic damage. Thus, at 24 h after transplantation, transaminase levels were reduced significantly when livers were preserved during 8 h in UW-PEG preservation solution compared with the original UW solution. In addition, histological findings revealed fewer and smaller areas of hepatocyte necrosis. The benefits of UW-PEG solution cannot be explained by modifications in oxidative stress or neutrophil accumulation associated with liver transplantation. However, the results of hepatic and portal blood flow indicated that the benefits of this modified preservation solution, UW-PEG were associated with improvements in the microcirculatory disorders after reperfusion. [Conclusions]: The UW-PEG solution, while retaining all the advantages of UW solution, improved hepatic ischemia-reperfusion injury associated with liver transplantation. © 2006 The Authors.This study was supported by the Ministerio de Ciencia y Tecnología (project grants SAF 2005-00385 and BFI 2003-00912, and Ramón y Cajal research contract to Carmen Peralta), the Minsterio de Asuntos Exteriores y Cooperación/Agencia Española de Cooperación Internacional (A4251/05 and CN0012/2002 research projects) and the Generalitat de Catalunya (2005 SGR/00781) I. Ben Mosbah holds a fellowship from the AECI.Peer Reviewe

Addition of carvedilol to University Wisconsin solution improves rat steatotic and nonsteatotic liver preservation

et al.Here we examine the effect of adding carvedilol (CVD) to University of Wisconsin (UW) solution on the preservation of steatotic and nonsteatotic livers during cold ischemia and after normothermic reperfusion. We used an isolated perfused rat liver model. The following protocols were evaluated. Protocol 1 concerned the effect of CVD after cold ischemia. Steatotic and nonsteatotic livers were preserved for 24 hours in UW solution alone or with CVD. Livers without cold ischemia were used as controls. Transaminases were evaluated in the flushing effluent. Protocol 2 involved the effect of CVD after reperfusion. Both liver types were preserved for 24 hours in UW solution alone or with CVD and then perfused ex vivo for 2 hours at 37°C. Livers flushed and perfused without ischemia were used as controls. Hepatic injury and functionality [transaminases, bile production, and hepatic clearance of sulfobromophthalein (BSP)] were evaluated after reperfusion. In addition, factors potentially involved in hepatic ischemia-reperfusion injury, including oxidative stress (malondialdehyde and superoxide anion levels), mitochondrial damage (glutamate dehydrogenase activity), microcirculatory disorders (flow rate and vascular resistance), and adenosine triphosphate (ATP) depletion, were evaluated after reperfusion. After cold ischemia, steatotic livers preserved in UW solution showed higher transaminase levels than nonsteatotic livers. After reperfusion, steatotic livers preserved in UW solution showed higher transaminase levels and lower bile production and BSP clearance than nonsteatotic livers. Alterations in the perfusion flow rate and vascular resistance, mitochondrial damage, and reduced ATP content were more evident in steatotic livers preserved in UW solution. The addition of CVD to UW solution reduced hepatic injury, obstructed its mechanisms, and improved hepatic functionality in both liver types. We conclude that CVD is a useful additive for UW solution that improves the preservation of steatotic and nonsteatotic livers subjected to prolonged cold ischemia. © 2010 AASLD.This study was supported by the Ministerio de Sanidad y Consumo (project grants PIO60021 and PI081988), Ministerio de Asuntos Exteriores y de Cooperación Internacional/AECI (project grants A/020255/08 and A/029087/09), the Generality of Catalonia (project 2005SGR/00781, AGAUR, and VALTEC08-02-0033, CIDEM), and the Catalan Foundation of Transplantation. The Network Center for Biomedical Research in Hepatic and Digestive Diseases is funded by the Carlos III Health Institute. Carmen Peralta participates in the Programa de Esatabilització d’Investigadors (Directorate of Strategy and Coordination, Department of Health, Generality of Catalonia).Peer Reviewe