Hypoxia inducible factor-1α accumulation in steatotic liver preservation: Role of nitric oxide

Open-Acces journal.-- et al.[Aim]: To examine the relevance of hypoxia inducible factor (HIF-1) and nitric oxide (NO) on the preservation of fatty liver against cold ischemia-reperfusion injury (IRI). Methods]: We used an isolated perfused rat liver model and we evaluated HIF-1α in steatotic and non-steatotic livers preserved for 24 h at 4°C in University of Wisconsin and IGL-1 solutions, and then subjected to 2 h of normothermic reperfusion. After normoxic reperfusion, liver enzymes, bile production, bromosulfophthalein clearance, as well as HIF-1α and NO [endothelial NO synthase (eNOS) activity and nitrites/nitrates] were also measured. Other factors associated with the higher susceptibility of steatotic livers to IRI, such as mitochondrial damage and vascular resistance were evaluated. [Results]: A significant increase in HIF-1α was found in steatotic and non-steatotic livers preserved in IGL-1 after cold storage. Livers preserved in IGL-1 showed a significant attenuation of liver injury and improvement in liver function parameters. These benefits were enhanced by the addition of trimetazidine (an antiischemic drug), which induces NO and eNOS activation, to IGL-1 solution. In normoxic reperfusion, the presence of NO favors HIF-1α accumulation, promoting also the activation of other cytoprotective genes, such as hemeoxygenase- 1. [Concluison]: We found evidence for the role of the HIF-1α/NO system in fatty liver preservation, especially when IGL-1 solution is used. © 2010 Baishideng.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/020255/08 and A/02987/09), MadridPeer Reviewe

Losartan activates sirtuin 1 in rat reduced-size orthotopic liver transplantation

© 2015 Baishideng Publishing Group Inc. All rights reserved. Aim: To investigate a possible association between losartan and sirtuin 1 (SIRT1) in reduced-size orthotopic liver transplantation (ROLT) in rats. Methods: Livers of male Sprague-Dawley rats (200-250 g) were preserved in University of Wisconsin preservation solution for 1 h at 4°C prior to ROLT. In an additional group, an antagonist of angiotensin II type 1 receptor (AT1R), losartan, was orally administered (5 mg/kg) 24 h and 1 h before the surgical procedure to both the donors and the recipients. Transaminase (as an indicator of liver injury), SIRT1 activity, and nicotinamide adenine dinucleotide (NAD+, a co-factor necessary for SIRT1 activity) levels were determined by biochemical methods. Protein expression of SIRT1, acetylated FoxO1 (ac-FoxO1), NAMPT (the precursor of NAD+), heat shock proteins (HSP70, HO-1) expression, endoplasmic reticulum stress (GRP78, IRE1α, p-eIF2) and apoptosis (caspase 12 and caspase 3) parameters were determined by Western blot. Possible alterations in protein expression of mitogen activated protein kinases (MAPK), such as p-p38 and p-ERK, were also evaluated. Furthermore, the SIRT3 protein expression and mRNA levels were examined. Results: The present study demonstrated that losartan administration led to diminished liver injury when compared to ROLT group, as evidenced by the significant decreases in alanine aminotransferase (358.3 133.44 vs 206 33.61, P + (0.87 0.22 vs 1.195 0.144, P < 0.05) the co-factor necessary for SIRT1 activity, as well as with decreases in ac-FoxO1 expression. Losartan treatment also provoked significant attenuation of endoplasmic reticulum stress parameters (GRP78, IRE1α, p-eIF2) which was consistent with reduced levels of both caspase 12 and caspase 3. Furthermore, losartan administration stimulated HSP70 protein expression and attenuated HO-1 expression. However, no changes were observed in protein or mRNA expression of SIRT3. Finally, the protein expression pattern of p-ERK and p-p38 were not altered upon losartan administration. Conclusion: The present study reports that losartan induces SIRT1 expression and activity, and that it reduces hepatic injury in a ROLT model.Supported by Grants from Fondo de Investigaciones Sanitarias, No. FIS PI12/00519; fellowship from Agència de Gestió d’Ajuts Universitaris i de Recerca, No. 2012FI_B00382; Generalitat de Catalunya, Barcelona, Catalonia, Spain (to Pantazi E)Peer Reviewe

Losartan activates sirtuin 1 in rat reduced-size orthotopic liver transplantation

© 2015 Baishideng Publishing Group Inc. All rights reserved. Aim: To investigate a possible association between losartan and sirtuin 1 (SIRT1) in reduced-size orthotopic liver transplantation (ROLT) in rats. Methods: Livers of male Sprague-Dawley rats (200-250 g) were preserved in University of Wisconsin preservation solution for 1 h at 4°C prior to ROLT. In an additional group, an antagonist of angiotensin II type 1 receptor (AT1R), losartan, was orally administered (5 mg/kg) 24 h and 1 h before the surgical procedure to both the donors and the recipients. Transaminase (as an indicator of liver injury), SIRT1 activity, and nicotinamide adenine dinucleotide (NAD+, a co-factor necessary for SIRT1 activity) levels were determined by biochemical methods. Protein expression of SIRT1, acetylated FoxO1 (ac-FoxO1), NAMPT (the precursor of NAD+), heat shock proteins (HSP70, HO-1) expression, endoplasmic reticulum stress (GRP78, IRE1α, p-eIF2) and apoptosis (caspase 12 and caspase 3) parameters were determined by Western blot. Possible alterations in protein expression of mitogen activated protein kinases (MAPK), such as p-p38 and p-ERK, were also evaluated. Furthermore, the SIRT3 protein expression and mRNA levels were examined. Results: The present study demonstrated that losartan administration led to diminished liver injury when compared to ROLT group, as evidenced by the significant decreases in alanine aminotransferase (358.3 133.44 vs 206 33.61, P + (0.87 0.22 vs 1.195 0.144, P < 0.05) the co-factor necessary for SIRT1 activity, as well as with decreases in ac-FoxO1 expression. Losartan treatment also provoked significant attenuation of endoplasmic reticulum stress parameters (GRP78, IRE1α, p-eIF2) which was consistent with reduced levels of both caspase 12 and caspase 3. Furthermore, losartan administration stimulated HSP70 protein expression and attenuated HO-1 expression. However, no changes were observed in protein or mRNA expression of SIRT3. Finally, the protein expression pattern of p-ERK and p-p38 were not altered upon losartan administration. Conclusion: The present study reports that losartan induces SIRT1 expression and activity, and that it reduces hepatic injury in a ROLT model.Supported by Grants from Fondo de Investigaciones Sanitarias, No. FIS PI12/00519; fellowship from Agència de Gestió d’Ajuts Universitaris i de Recerca, No. 2012FI_B00382; Generalitat de Catalunya, Barcelona, Catalonia, Spain (to Pantazi E)Peer Reviewe

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

Endoplasmic reticulum stress inhibition protects steatotic and non-steatotic livers in partial hepatectomy under ischemia-reperfusion

During partial hepatectomy, ischemia-reperfusion (I/R) is commonly applied in clinical practice to reduce blood flow. Steatotic livers show impaired regenerative response and reduced tolerance to hepatic injury. We examined the effects of tauroursodeoxycholic acid (TUDCA) and 4-phenyl butyric acid (PBA) in steatotic and non-steatotic livers during partial hepatectomy under I/R (PH + I/R). Their effects on the induction of unfolded protein response (UPR) and endoplasmic reticulum (ER) stress were also evaluated. We report that PBA, and especially TUDCA, reduced inflammation, apoptosis and necrosis, and improved liver regeneration in both liver types. Both compounds, especially TUDCA, protected both liver types against ER damage, as they reduced the activation of two of the three pathways of UPR (namely inositol-requiring enzyme and PKR-like ER kinase) and their target molecules caspase 12, c-Jun N-terminal kinase and C/EBP homologous protein-10. Only TUDCA, possibly mediated by extracellular signal-regulated kinase upregulation, inactivated glycogen synthase kinase-3β. This is turn, inactivated mitochondrial voltage-dependent anion channel, reduced cytochrome c release from the mitochondria and caspase 9 activation and protected both liver types against mitochondrial damage. These findings indicate that chemical chaperones, especially TUDCA, could protect steatotic and non-steatotic livers against injury and regeneration failure after PH + I/R. © 2010 Macmillan Publishers Limited.This work was supported by the Ministerio de Educación y Ciencia (project grant SAF 2005-00385; project grant manager BFU2009-07410) (Madrid, Spain) and the Ministerio de Sanidad y Consumo (project grant PIO60021) (Madrid, Spain). Centro de Investigaciones Biomédicas Esther Koplowitz, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas is supported by the Instituto de Salud Carlos III (Spain).Peer Reviewe

Unpublished Mediterranean records of marine alien and cryptogenic species

Good datasets of geo-referenced records of alien species are a prerequisite for assessing the spatio-temporal dynamics of biological invasions, their invasive potential, and the magnitude of their impacts. However, with the exception of first records on a country level or wider regions, observations of species presence tend to remain unpublished, buried in scattered repositories or in the personal databases of experts. Through an initiative to collect, harmonize and make such unpublished data for marine alien and cryptogenic species in the Mediterranean Sea available, a large dataset comprising 5376 records was created. It includes records of 239 alien or cryptogenic taxa (192 Animalia, 24 Plantae, 23 Chromista) from 19 countries surrounding the Mediterranean Sea. In terms of records, the most reported Phyla in descending order were Chordata, Mollusca, Chlorophyta, Arthropoda, and Rhodophyta. The most recorded species was Caulerpa cylindracea, followed by Siganus luridus, Magallana sp. (cf. gigas or angulata) and Pterois miles. The dataset includes records from 1972 to 2020, with the highest number of records observed in 2018. Among the records of the dataset, Dictyota acutiloba is a first record for the Mediterranean Sea. Nine first country records are also included: the alga Caulerpa taxifolia var. distichophylla, the cube boxfish Ostracion cubicus, and the cleaner shrimp Urocaridella pulchella from Israel; the sponge Paraleucilla magna from Libya and Slovenia; the lumpfish Cyclopterus lumpus from Cyprus; the bryozoan Celleporaria vermiformis and the polychaetes Prionospio depauperata and Notomastus aberans from Malta

Unpublished Mediterranean and Black Sea records of marine alien, cryptogenic, and neonative species

To enrich spatio-temporal information on the distribution of alien, cryptogenic, and neonative species in the Mediterranean and the Black Sea, a collective effort by 173 marine scientists was made to provide unpublished records and make them open access to the scientific community. Through this effort, we collected and harmonized a dataset of 12,649 records. It includes 247 taxa, of which 217 are Animalia, 25 Plantae and 5 Chromista, from 23 countries surrounding the Mediterranean and the Black Sea. Chordata was the most abundant taxonomic group, followed by Arthropoda, Mollusca, and Annelida. In terms of species records, Siganus luridus, Siganus rivulatus, Saurida lessepsianus, Pterois miles, Upeneus moluccensis, Charybdis (Archias) longicollis, and Caulerpa cylindracea were the most numerous. The temporal distribution of the records ranges from 1973 to 2022, with 44% of the records in 2020–2021. Lethrinus borbonicus is reported for the first time in the Mediterranean Sea, while Pomatoschistus quagga, Caulerpa cylindracea, Grateloupia turuturu, and Misophria pallida are first records for the Black Sea; Kapraunia schneideri is recorded for the second time in the Mediterranean and for the first time in Israel; Prionospio depauperata and Pseudonereis anomala are reported for the first time from the Sea of Marmara. Many first country records are also included, namely: Amathia verticillata (Montenegro), Ampithoe valida (Italy), Antithamnion amphigeneum (Greece), Clavelina oblonga (Tunisia and Slovenia), Dendostrea cf. folium (Syria), Epinephelus fasciatus (Tunisia), Ganonema farinosum (Montenegro), Macrorhynchia philippina (Tunisia), Marenzelleria neglecta (Romania), Paratapes textilis (Tunisia), and Botrylloides diegensis (Tunisia).peer-reviewe

Noves estratègies per la millora de la conservació dels empelts hepàtics esteatòsics

La síndrome d'isquèmia-reperfusió (IR) inherent al trasplantament hepàtic correspon al dany no immunològic de l'empelt que resulta dels processos peri operatoris implicats en l'extracció, la preservació i la reperfusió del fetge donant. s'han descrit diversos mètodes de preservació de l'empelt hepàtic, el més comú és el de la preservació hipotèrmica, en què s'empra una solució de preservació entre 0 i 4 ºC. La composició de la solució de preservació és un factor crític per a la viabilitat de l'empelt. En el cas de l'empelt hepàtic, la solució de preservació més utilitzada en la pràctica clínica és la solució de la Universitat de Wisconsin (UW). Aquesta solució de preservació ha aconseguit ampliar el temps d'isquèmia freda, però hi ha lesions considerables en l'empelt quan el temps d'isquèmia freda es prolonga més de 24 hores. Una altra de les limitacions de la solució de UW és la presència d'hidroxietilmidó (HEA), que en ser proagregant de glòbuls vermells pot produir un rentat incomplet de l'empelt hepàtic, amb la consegüent estasi venosa i resposta inflamatòria. Se sap també que l'alta concentració de potassi present en la UW pot conduir a arítmies cardíaques. Recentment, una nova solució de preservació, (anomenada IGL-1), caracteritzada per la inversió de la concentració de K+ i de Na+ i la substitució d'HEA present en l'UW, pel polietilénglicol (PEG) ha resultat ser eficaç en trasplantament de fetge. Per causa de la manca de donants, moltes de les investigacions actuals en el camp del trasplantament hepàtic van dirigides a la possible utilització dels òrgans subòptims o marginals com a estratègia per augmentar el nombre d'òrgans disponibles per ser trasplantats. En aquest grup són d'especial interès els fetges esteatòsics, gràcies a la seva alta prevalença entre els possibles donants però presenten una major vulnerabilitat a la lesió per IR. els objectius d'aquesta tesi estan dirigits en primer lloc, a avaluar l'ús de la nova solució de preservació IGL-1 per a la preservació dels fetges esteatòsics, i en segon lloc, a enriquir el líquid amb diferents molècules per optimitzar aquesta etapa de conservació. Amb aquesta finalitat, s'han desenvolupat els objectius següents: 1. Comparar la qualitat de preservació dels empelts hepàtics esteatòsics en les solucions de conservació UW, IGL-1 i IGL-1 enriquida amb La trimetazidina (TMZ) i determinar els mecanismes protectors, 2. Avaluar els efectes de l'enriquiment de la solució IGL-1 amb el factor de creixement IGF-1 sobre la preservació de l'empelt hepàtic esteatòsic i determinar les possibles vies de senyalització implicades en l'efecte protector, 3. I per últim, s'ha avaluat l'efecte de l'addició de la melatonina a la solució IGL-1 després de 24 hores d'isquèmia freda. Els resultats obtinguts en aquesta tesi confirmen que els empelts esteatòsics són més vulnerables a la lesió induïda per isquèmia freda que no els fetges no esteatósics.La preservació d'ambdós tipus de fetges en la solució IGL-1 va dur a nivells més baixos de transaminases i a una major producció de bilis, comparat amb els fetges preservats en la solució estàndard, la UW. En un segon pas vam afegir a la solució IGL-1 la TMZ. La TMZ és una droga anti-isquèmica, l'eficàcia de la qual ja ha estat demostrada en diversos estudis. Els resultats mostren que la TMZ indueix l'acumulació de HIF-1¿ durant les 24 hores de preservació hipotèrmica. Els efectes beneficiosos de l'estabilització de l'HIF-1¿ en normòxia estan relacionats amb l'augment de l'activitat de l'eNOS constitutiva en empelts conservats en IGL-1 enriquida amb TMZ. En el nostre segon estudi, hem avaluat l'efecte de l'addició d'IGF-1 a la solució IGL-1. Hem demostrat que l'addició d'IGF-1 millora la preservació dels fetges, i que els efectes beneficiosos es relacionen amb l'activació de la via de senyalització de la PI-3 cinasa que condueix a l'activació i la fosforilació d'Akt i la seva diana eNOS. En l'últim capítol d'aquesta tesi, ens hem compromès a estudiar l'efecte de la melatonina en la preservació dels empelts esteatòsics. Els nostres resultats en aquest capítol han demostrat que la melatonina redueix els nivells de RLO i la peroxidació lipídica. També, l'addició d'aquesta hormona a la solució IGL-1 augmenta la producció de bilis, disminueix la resistència vascular i redueix la secreció de citocines proinflamatòries com el TNF-¿ i altres adipocitocines com ara l'adiponectina. En conclusió, l'enriquiment de la solució IGL-1 amb l'IGF-1, la TMZ i la melatonina ha millorat la conservació de l'empelt hepàtic esteatòsic via l'activació de diverses vies de senyalització tals com la del sistema HIF-1¿/NO ,la de l' AKT i la de l'eNOS.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