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1.
Sci Rep ; 11(1): 7237, 2021 03 31.
Artículo en Inglés | MEDLINE | ID: mdl-33790343

RESUMEN

After a stroke event, most survivors suffer from arm paresis, poor motor control and other disabilities that make activities of daily living difficult, severely affecting quality of life and personal independence. This randomized controlled trial aimed at evaluating the efficacy of a music-based sonification approach on upper limbs motor functions, quality of life and pain perceived during rehabilitation. The study involved 65 subacute stroke individuals during inpatient rehabilitation allocated into 2 groups which underwent usual care dayweek) respectively of standard upper extremity motor rehabilitation or upper extremity treatment with sonification techniques. The Fugl-Meyer Upper Extremity Scale, Box and Block Test and the Modified Ashworth Scale were used to perform motor assessment and the McGill Quality of Life-it and the Numerical Pain Rating Scale to assess quality of life and pain. The assessment was performed at baseline, after 2 weeks, at the end of treatment and at follow-up (1 month after the end of treatment). Total scores of the Fugl-Meyer Upper Extremity Scale (primary outcome measure) and hand and wrist sub scores, manual dexterity scores of the affected and unaffected limb in the Box and Block Test, pain scores of the Numerical Pain Rating Scale (secondary outcomes measures) significantly improved in the sonification group compared to the standard of care group (time*group interaction < 0.05). Our findings suggest that music-based sonification sessions can be considered an effective standardized intervention for the upper limb in subacute stroke rehabilitation.


Asunto(s)
Musicoterapia , Calidad de Vida , Recuperación de la Función , Rehabilitación de Accidente Cerebrovascular , Accidente Cerebrovascular/fisiopatología , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad
2.
Free Radic Biol Med ; 112: 141-148, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-28739531

RESUMEN

Steatosis intensifies hepatic ischemia/reperfusion (I/R) injury increasing hepatocyte damage and hepatic inflammation. This study evaluates if this process is associated to a differential response of steatotic hepatocytes (HP) and Kupffer cells (KC) to I/R injury and investigates the molecular mechanisms involved. Control or steatotic (treated with 50 µmol palmitic acid, PA) mouse HP or KC were exposed to hypoxia/reoxygenation (H/R). C57BL/6 mice fed 9 week with control or High Fat diet underwent to partial hepatic IR. PA increased H/R damage of HP and further activated the ASK1-JNK axis stimulated by ER stress during H/R. PA also induced the production of oxidant species (OS), and OS prevention nullified the capacity of PA to increase H/R damage and ASK1/JNK stimulation. ASK1 inhibition prevented JNK activation and entirely protected HP damage. In KC, PA directly activated ER stress, ASK1 and p38 MAPK and increased H/R damage. However, in contrast to HP, ASK1 inhibition further increased H/R damage by preventing p38 MAPK activation. In mice liver, steatosis induced the expression of activated ASK1 in only KC, whereas I/R exposure of steatotic liver activated ASK1 expression also in HP. "In vivo", ASK1 inhibition prevented ASK1, JNK and p38 MAPK activation and protected I/R damage and expression of inflammatory markers. CONCLUSIONS: Lipids-induced ASK1 stimulation differentially affects HP and KC by promoting cytotoxic or protective signals. ASK1 increases H/R damage of HP by stimulating JNK and protects KC activating p38MAPK. These data support the potentiality of the therapeutic employment of ASK1 inhibitors that can antagonize the damaging effects of I/R upon fatty liver surgery by the contextual reduction of HP death and of KC-mediated reactions.


Asunto(s)
Hígado Graso/genética , Hepatocitos/enzimología , Macrófagos del Hígado/enzimología , Hígado/enzimología , MAP Quinasa Quinasa Quinasa 5/genética , Daño por Reperfusión/genética , Animales , Dieta Alta en Grasa/efectos adversos , Estrés del Retículo Endoplásmico/genética , Hígado Graso/enzimología , Hígado Graso/etiología , Hígado Graso/patología , Regulación de la Expresión Génica , Hepatocitos/efectos de los fármacos , Hepatocitos/patología , Macrófagos del Hígado/efectos de los fármacos , Macrófagos del Hígado/patología , Hígado/patología , Hígado/cirugía , MAP Quinasa Quinasa 4/genética , MAP Quinasa Quinasa 4/metabolismo , MAP Quinasa Quinasa Quinasa 5/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Estrés Oxidativo , Ácido Palmítico/farmacología , Cultivo Primario de Células , Daño por Reperfusión/enzimología , Daño por Reperfusión/patología , Transducción de Señal , Proteínas Quinasas p38 Activadas por Mitógenos/genética , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo
3.
Eur J Phys Rehabil Med ; 53(2): 240-248, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27676203

RESUMEN

BACKGROUND: Several robotic devices have been proposed for upper limb rehabilitation, but they differ in terms of application fields and the technical solutions implemented. AIM: The aim of this study was to compare the effectiveness of three different robotic devices for shoulder-elbow rehabilitation in reducing motor impairment and improving motor performance in post-stroke patients. DESIGN: Retrospective multi-center study. SETTING: Inpatient rehabilitation hospital. POPULATION: Eighty-seven chronic and subacute post-stroke patients, aged 48-85 years. METHODS: Data were obtained through a retrospective analysis of patients who underwent a 3-week rehabilitation program including robot-assisted therapy of the upper limb and conventional physical therapy. Patients were divided into three groups according to the robot device used for exercise training: 'Braccio di Ferro" (BdF), InMotion2 (IMT), and MEchatronic system for MOtor recovery after Stroke (MEMOS). They were evaluated at the beginning and end of treatment using the Fugl-Meyer (FM) and Modified Ashworth (MAS) clinical scales and by a set of robot measured kinematic parameters. RESULTS: The three groups were homogeneous for age, level of impairment, time since the acute event, and spasticity level. A significant effect of time (P<0.001) was evident on FM and kinematic parameters across all groups. The average change in the FM score was 9.5, 7.3 and 7.1 points, respectively, for BdF, IMT and MEMOS. No significant between-group differences were observed at the MAS pre- vs. post-treatment. A significant interaction between time and groups resulted for the mean velocity (MV, P<0.005) and movement smoothness parameters (nPK, P<0.001 and SM, P<0.02). The effect size (ES) was large for the FM score and MV parameter, independently of the type of robot device used. Further, the ES ranged from moderate to large for the remaining kinematic parameters except for the movement accuracy (mean distance, MD), which exhibited a small ES in the BdF and MEMOS groups. CONCLUSIONS: The motor function gains obtained during robot-assisted therapy of stroke patients seem to be independent of the type of robot device used for the training program. All devices tested in this study were effective in improving the level of impairment and motor performance. CLINICAL REHABILITATION IMPACT: This study could help rehabilitation professionals to set-up comparative studies involving rehabilitation technologies.


Asunto(s)
Terapia por Ejercicio/métodos , Ejercicio Físico/fisiología , Desempeño Psicomotor/fisiología , Robótica/instrumentación , Rehabilitación de Accidente Cerebrovascular/métodos , Accidente Cerebrovascular/fisiopatología , Extremidad Superior/fisiopatología , Anciano , Anciano de 80 o más Años , Enfermedad Crónica , Diseño de Equipo , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Recuperación de la Función , Estudios Retrospectivos , Accidente Cerebrovascular/psicología , Factores de Tiempo
4.
Transl Res ; 182: 75-87, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-28011152

RESUMEN

Lipotoxicity and immunoinflammation are associated with the evolution of steatosis toward nonalcoholic steatohepatitis (NASH). This study reports the ability of adenosine A2a receptor (A2aR) activation to inhibit NASH development by modulating the responses of CD4+ T-helper (Th) cells to avoid an immuno-mediated potentiation of lipotoxicity. The effect of the A2aR agonist CGS21680 on immunoinflammatory signals, CD4+Th cell infiltration and immunolipotoxicity was analyzed in steatotic C57BL/6 mice fed with a methionine-choline-deficient (MCD) diet and in mouse hepatocytes exposed to palmitic acid (PA). CGS21680 inhibited NASH development in steatotic mice and decreased cytokines and chemokines involved in Th cell recruitment or polarization (namely CXCL10, CCL2, tumor necrosis factor alfa [TNFα], tumor growth factor [TGFß], and IL-12). CGS21680 also reduced the expansion of Th17, Th22, and Th1 cells and increased the immunosuppressive activity of T regulatory cells. In PA-treated mice hepatocytes, CGS21680 inhibited the production of CXCL10, TNFα, TGFß, IL-12, and CCL2; CGS21680 also prevented JNK-dependent lipotoxicity and its intensification by IL-17 or IL-17 plus IL-22 through Akt/PI3-kinase stimulation and inhibition of the negative regulator of PI3-kinase, (phosphatase and tensin homologue deleted from chromosome 10 (PTEN), which is upregulated by IL-17. In MCD livers, CGS21680 reduced JNK activation and PTEN expression and increased Akt phosphorylation. In conclusion, A2aR stimulation inhibited NASH development by reducing Th17 cell expansion and inhibiting the exacerbation of the IL-17-induced JNK-dependent lipotoxicity. These data promote the implementation of further studies to evaluate the potential clinical application of A2aR agonists that, by being able to function as both cytoprotective and immunomodulatory agents, could efficiently antagonize the multi-faced pathogenesis of NASH.


Asunto(s)
Lípidos/toxicidad , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Enfermedad del Hígado Graso no Alcohólico/inmunología , Receptor de Adenosina A2A/metabolismo , Transducción de Señal/efectos de los fármacos , Adenosina/análogos & derivados , Adenosina/farmacología , Adenosina/uso terapéutico , Animales , Progresión de la Enfermedad , Activación Enzimática/efectos de los fármacos , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Inflamación/inmunología , Inflamación/patología , Masculino , Ratones Endogámicos C57BL , Enfermedad del Hígado Graso no Alcohólico/enzimología , Enfermedad del Hígado Graso no Alcohólico/patología , Fenetilaminas/farmacología , Fenetilaminas/uso terapéutico , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Linfocitos T Colaboradores-Inductores/efectos de los fármacos , Linfocitos T Colaboradores-Inductores/inmunología , Linfocitos T Reguladores/efectos de los fármacos , Linfocitos T Reguladores/inmunología
5.
Clin Sci (Lond) ; 130(3): 193-203, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26558403

RESUMEN

The mechanisms responsible for the evolution of steatosis towards NASH (non-alcoholic steatohepatitis) and fibrosis are not completely defined. In the present study we evaluated the role of CD4(+) T-helper (Th) cells in this process. We analysed the infiltration of different subsets of CD4(+) Th cells in C57BL/6 mice fed on a MCD (methionine choline-deficient) diet, which is a model reproducing all phases of human NASH progression. There was an increase in Th17 cells at the beginning of NASH development and at the NASH-fibrosis transition, whereas levels of Th22 cells peaked between the first and the second expansion of Th17 cells. An increase in the production of IL (interleukin)-6, TNFα (tumour necrosis factor α), TGFß (transforming growth factor ß) and CCL20 (CC chemokine ligand 20) accompanied the changes in Th17/Th22 cells. Livers of IL-17(-/-) mice were protected from NASH development and characterized by an extensive infiltration of Th22 cells. In vitro, IL-17 exacerbated the JNK (c-Jun N-terminal kinase)-dependent mouse hepatocyte lipotoxicity induced by palmitate. IL-22 prevented lipotoxicity through PI3K (phosphoinositide 3-kinase)-mediated inhibition of JNK, but did not play a protective role in the presence of IL-17, which up-regulated the PI3K/Akt inhibitor PTEN (phosphatase and tensin homologue deleted on chromosome 10). Consistently, livers of IL-17(-/-) mice fed on the MCD diet displayed decreased activation of JNK, reduced expression of PTEN and increased phosphorylation of Akt compared with livers of wild-type mice. Hepatic infiltration of Th17 cells is critical for NASH initiation and development of fibrosis in mice, and reflects an infiltration of Th22 cells. Th22 cells are protective in NASH, but only in the absence of IL-17. These data strongly support the potentiality of clinical applications of IL-17 inhibitors that can prevent NASH by both abolishing the lipotoxic action of IL-17 and allowing IL-22-mediated protection.


Asunto(s)
Enfermedad del Hígado Graso no Alcohólico/inmunología , Linfocitos T Colaboradores-Inductores/fisiología , Linfocitos T Reguladores/fisiología , Animales , Modelos Animales de Enfermedad , Interleucina-17/deficiencia , Interleucinas/metabolismo , Hígado/inmunología , Masculino , Ratones Endogámicos C57BL , Interleucina-22
6.
Biomed Res Int ; 2015: 286746, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26539478

RESUMEN

Ischemic preconditioning (IP) of the liver by a brief interruption of the blood flow protects the damage induced by a subsequent ischemia/reperfusion (I/R) preventing parenchymal and nonparenchymal liver cell damage. The discovery of IP has shown the existence of intrinsic systems of cytoprotection whose activation can stave off the progression of irreversible tissue damage. Deciphering the molecular mediators that underlie the cytoprotective effects of preconditioning can pave the way to important therapeutic possibilities. Pharmacological activation of critical mediators of IP would be expected to emulate or even to intensify its salubrious effects. In vitro and in vivo studies have demonstrated the role of the adenosine A2a receptor (A2aR) as a trigger of liver IP. This review will provide insight into the phenotypic changes that underline the resistance to death of liver cells preconditioned by pharmacological activation of A2aR and their implications to develop innovative strategies against liver IR damage.


Asunto(s)
Citoprotección/efectos de los fármacos , Hígado/efectos de los fármacos , Receptor de Adenosina A2A/uso terapéutico , Daño por Reperfusión/tratamiento farmacológico , Hepatocitos/efectos de los fármacos , Humanos , Precondicionamiento Isquémico , Hígado/irrigación sanguínea , Hígado/lesiones , Daño por Reperfusión/fisiopatología , Transducción de Señal/efectos de los fármacos
7.
J Hepatol ; 62(3): 573-80, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25315650

RESUMEN

BACKGROUND & AIMS: Ischemia-reperfusion (IR) of liver results in hepatocytes (HP) and sinusoidal endothelial cells (LSEC) irreversible damage. Ischemic preconditioning protects IR damage upon adenosine A2a receptor (A2aR) stimulation. Understanding the phenotypic changes that underlie hepatocellular damage and protection is critical to optimize strategies against IR. METHODS: The proteome of HP and LSEC, isolated from sham or IR exposed mice, receiving or not the A2aR agonist CGS21680 (0.5mg/kg b.w.), was analyzed by 2-D DIGE/MALDI-TOF. RESULTS: We identified 64 proteins involved in cytoprotection, regeneration, energy metabolism and response to oxidative stress; among them, 34 were associated with IR injury and A2aR protection. The main pathways, downregulated by IR and upregulated by CGS21680 in HP and LSEC, were related to carbohydrate, protein and lipid supply and metabolism. In LSEC, IR reduced stress response enzymes that were instead upregulated by CGS21680 treatment. Functional validation experiments confirmed the metabolic involvement and showed that inhibition of pyruvate kinase, 3-chetoacylCoA thiolase, and arginase reduced the protection by CGS21680 of in vitro hypoxia-reoxygenation injury, whereas their metabolic products induced liver cell protection. Moreover, LSEC, but not HP, were sensitive to H2O2-induced oxidative damage and CGS21680 protected against this effect. CONCLUSIONS: IR and A2aR stimulation produces pathological and protected liver cell phenotypes, respectively characterized by down- and upregulation of proteins involved in the response to O2 and nutrients deprivation during ischemia, oxidative stress, and reactivation of aerobic energy synthesis at reperfusion. This provides novel insights into IR hepatocellular damage and protection, and suggests additional therapeutic options.


Asunto(s)
Hepatocitos/metabolismo , Hepatocitos/patología , Hígado/lesiones , Receptor de Adenosina A2A/metabolismo , Daño por Reperfusión/etiología , Adenosina/análogos & derivados , Adenosina/farmacología , Agonistas del Receptor de Adenosina A2/farmacología , Animales , Antioxidantes/farmacología , Citoprotección/efectos de los fármacos , Células Endoteliales/efectos de los fármacos , Células Endoteliales/metabolismo , Células Endoteliales/patología , Hepatocitos/efectos de los fármacos , Metabolismo de los Lípidos/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Fenetilaminas/farmacología , Proteoma/metabolismo , Daño por Reperfusión/metabolismo , Daño por Reperfusión/prevención & control
8.
Clin Sci (Lond) ; 123(5): 323-32, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22439844

RESUMEN

NEFA (non-esterified 'free' fatty acid)-mediated lipotoxicity plays a critical role in the pathogenesis of NASH (non-alcoholic steatohepatitis). In the light of the growing need for new therapeutic options for NASH, we investigated the action of A2aR (adenosine A(2a) receptor) stimulation against lipotoxicity. The effects of the A(2a)R agonist CGS21680 [2-p-(2-carboxyethyl)phenethylamino-5'-N-ethylcarboxyamidoadenosine] were evaluated 'in vitro' in liver cells exposed to SA (stearic acid) and 'in vivo' in rats with NASH induced by 8 weeks of feeding with an MCD diet (methionine/choline-deficient diet). In cultured hepatocytes, SA promoted apoptosis by inducing MKK4 (mitogen-activated protein kinase kinase 4)/SEK1 (stress-activated protein kinase/extracellular-signal-regulated kinase kinase-1) and JNK-1/2 (c-Jun N-terminal kinase-1/2) activation. CGS21680 addition prevented JNK-1/2 activation and reduced apoptosis without interfering with lipid accumulation. CGS21680 action required PI3K (phosphoinositide 3-kinase)/Akt-mediated block of MKK4/SEK1. Consistently, PI3K inhibition with wortmannin abolished the cytoprotective action of CGS21680 and reverted MKK4 inhibition. SA lipotoxicity was also prevented by transfecting HTC cells with a specific MKK4/SEK1 siRNA (small interfering RNA). In rats receiving the MCD diet, the development of NASH was associated with MKK4/SEK1 and JNK-1/2 activation. CGS21680 (0.5 mg/kg of body weight, intraperitoneal) administration to MCD-fed rats prevented JNK-1/2 activation by acting on MKK4/SEK1. CGS21680 also effectively reduced NASH-associated ALT (alanine aminotransferase) release, hepatocyte apoptosis, liver inflammation and fibrosis without affecting hepatic steatosis. Taken together, these results demonstrate that, by inhibiting JNK-1/2, A(2a)R stimulation reduces lipotoxicity and ameliorates NASH, giving a rationale to investigate A(2a)R agonists as possible new therapeutic agents in preventing fatty liver progression to NASH.


Asunto(s)
Agonistas del Receptor de Adenosina A2/uso terapéutico , Adenosina/análogos & derivados , Hígado Graso/prevención & control , Fenetilaminas/uso terapéutico , Adenosina/farmacología , Adenosina/uso terapéutico , Agonistas del Receptor de Adenosina A2/farmacología , Animales , Apoptosis/efectos de los fármacos , Biomarcadores/metabolismo , Células Cultivadas , Esquema de Medicación , Hígado Graso/metabolismo , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Inyecciones Intraperitoneales , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Masculino , Enfermedad del Hígado Graso no Alcohólico , Fenetilaminas/farmacología , Ratas , Ratas Wistar , Reacción en Cadena en Tiempo Real de la Polimerasa , Receptores de Adenosina A2/metabolismo , Ácidos Esteáricos/toxicidad
9.
Liver Transpl ; 17(4): 474-82, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21445931

RESUMEN

Postconditioning is a procedure based on the induction of intracellular protective reactions immediately after the onset of reperfusion. Because of the growing need to prevent ischemia/reperfusion (I/R) injury during liver surgery and transplantation, we investigated the possibility of pharmacologically inducing hepatic postconditioning. The effects of the adenosine A2A receptor agonist 2p-(2-carboxyethyl)-phenyl-amino-5'-N-ethylcarboxyamido-adenosine (CGS21680; 5 µmol/L) and the phosphatase and tensin homologue deleted from chromosome 10 (PTEN) inhibitor dipotassium bisperoxo-(5-hydroxypyridine-2-carboxyl)-oxovanadate [bpV(HOpic); 250 nmol/L] were investigated in primary rat hepatocytes during reoxygenation after 24 hours of cold storage and in an in vivo model of rat liver warm I/R. The addition of CGS21680 at reoxygenation significantly reduced hepatocyte death through the activation of the phosphoinositide 3-kinase (PI3K)-protein kinase B (PKB)/Akt signal pathway and through the reduction of the intracellular level of PTEN. PTEN lowering was associated with the increased generation of reactive oxygen species after A2A receptor-mediated stimulation of ß-nicotinamide adenine dinucleotide phosphate oxidase (NOX). The inhibition of PI3K or NOX with wortmannin or diphenyleneiodonium chloride, respectively, and the addition of the antioxidant N,N'-diphenyl-p-phenylenediamine reversed the effects of CGS21680. The PTEN inhibitor bpV(HOpic) mimicked the protection provided by CGS21680 against reoxygenation damage. An in vivo rat treatment with CGS21680 or bpV(HOpic) during reperfusion after 1 hour of partial hepatic ischemia also promoted PKB/Akt activation and ameliorated alanine aminotransferase release and histological lesions induced by 2 hours of reperfusion. We conclude that adenosine A2A receptor agonists and PTEN inhibitors are possibly useful agents for the pharmacological induction of postconditioning in the liver.


Asunto(s)
Agonistas del Receptor de Adenosina A2/farmacología , Adenosina/análogos & derivados , Hígado/irrigación sanguínea , Fenetilaminas/farmacología , Daño por Reperfusión/prevención & control , Adenosina/farmacología , Animales , Masculino , Estrés Oxidativo , Fosfohidrolasa PTEN/análisis , Fosfohidrolasa PTEN/antagonistas & inhibidores , Ratas , Ratas Wistar
10.
World J Gastroenterol ; 16(48): 6058-67, 2010 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-21182220

RESUMEN

Ischemia/reperfusion (I/R) injury still represents an important cause of morbidity following hepatic surgery and limits the use of marginal livers in hepatic transplantation. Transient blood flow interruption followed by reperfusion protects tissues against damage induced by subsequent I/R. This process known as ischemic preconditioning (IP) depends upon intrinsic cytoprotective systems whose activation can inhibit the progression of irreversible tissue damage. Compared to other organs, liver IP has additional features as it reduces inflammation and promotes hepatic regeneration. Our present understanding of the molecular mechanisms involved in liver IP is still largely incomplete. Experimental studies have shown that the protective effects of liver IP are triggered by the release of adenosine and nitric oxide and the subsequent activation of signal networks involving protein kinases such as phosphatidylinositol 3-kinase, protein kinase C δ/ε and p38 MAP kinase, and transcription factors such as signal transducer and activator of transcription 3, nuclear factor-κB and hypoxia-inducible factor 1. This article offers an overview of the molecular events underlying the preconditioning effects in the liver and points to the possibility of developing pharmacological approaches aimed at activating the intrinsic protective systems in patients undergoing liver surgery.


Asunto(s)
Precondicionamiento Isquémico , Hígado/irrigación sanguínea , Hígado/patología , Daño por Reperfusión/patología , Adenosina/metabolismo , Adenosina Trifosfato/metabolismo , Humanos , Factor 1 Inducible por Hipoxia/metabolismo , Óxido Nítrico/metabolismo , Factores de Transcripción STAT/metabolismo , Transducción de Señal/fisiología
11.
J Hepatol ; 50(5): 937-47, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19303157

RESUMEN

BACKGROUND/AIMS: The efficacy of ischemic preconditioning (IPC) in preventing reperfusion injury in human liver transplants is still questioned. Phosphoinositide-3-kinase (PI3K) is essential for IPC development in rodent livers. This work investigates whether PI3K-dependent signals might account for the inconsistent responses to IPC of transplanted human livers. METHODS: Forty livers from deceased donors were randomized to receive or not IPC before recovery. PI3K activation was evaluated in biopsies obtained immediately before IPC and 2 h after reperfusion by measuring the phosphorylation of the PI3K downstream kinase PKB/Akt and the levels of the PI3K antagonist phosphatase tensin-homologue deleted from chromosome 10 (PTEN). RESULTS: IPC increased PKB/Akt phosphorylation (p = 0.01) and decreased PTEN levels (p = 0.03) in grafts, but did not significantly ameliorate post-transplant reperfusion injury. By calculating T(2h)/T(0) PKB/Akt phosphorylation ratios, 10/19 (53%) of the preconditioned grafts had ratios above the control threshold (IPC-responsive), while the remaining nine grafts showed ratios comparable to controls (IPC-non-responsive). T(2h)/T(0) PTEN ratios were also decreased (p < or = 0.03) only in IPC-responsive grafts. The patients receiving IPC-responsive organs had ameliorated (p < or = 0.05) post-transplant aminotransferase and bilirubin levels, while prothrombin activity was unchanged. CONCLUSIONS: Impaired PI3K signaling might account for the variability in the responses to IPC of human grafts from deceased donors.


Asunto(s)
Precondicionamiento Isquémico , Trasplante de Hígado/fisiología , Fosfatidilinositol 3-Quinasas/metabolismo , Daño por Reperfusión/prevención & control , Adulto , Anciano , Anciano de 80 o más Años , Biopsia , Femenino , Humanos , Hígado/enzimología , Hígado/patología , Masculino , Persona de Mediana Edad , Fosfohidrolasa PTEN/metabolismo , Fosfohidrolasa PTEN/fisiología , Fosforilación , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal/fisiología , Tolerancia al Trasplante/fisiología
12.
Hepatology ; 48(1): 230-9, 2008 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-18506850

RESUMEN

UNLABELLED: The cellular mechanisms by which ischemic preconditioning increases liver tolerance to ischemia/reperfusion injury are still poorly understood. This study investigated the role of the hypoxia-inducible factor-1 (HIF-1) in the protection associated with the late phase of liver preconditioning. Late preconditioning was induced in primary cultured rat hepatocytes by a transient (10 minute) hypoxic stress or by 15 minutes incubation with the adenosine A(2A) receptors agonist CGS21680 24 hours before exposure to 90 minutes of hypoxia in a serum-free medium. Late preconditioning induced the nuclear translocation of HIF-1 and the expression of carbonic anhydrase IX (CAIX), a HIF-1-regulated transmembrane enzyme that catalyzes bicarbonate production. Such effects were associated with prevention of hepatocyte killing by hypoxia and the amelioration of intracellular acidosis and Na+ accumulation. The inhibition of PKC-mediated and PI3-kinase-mediated signals with, respectively, chelerythrine and wortmannin abolished HIF-1 activation and blocked both CAIX expression and the protective action of late preconditioning. CAIX expression was also prevented by interfering with the transcriptional activity of HIF-1 using a dominant negative HIF-1beta subunit. The inhibition of CAIX with acetazolamide or the block of bicarbonate influx with disodium-4-acetamido-4'-isothiocyanato-stilben-2,2'-disulfonate also reverted the protective effects of late preconditioning on intracellular acidosis and Na+ accumulation. CONCLUSION: The stimulation of adenosine A(2A) receptors induced late preconditioning in liver cells through the activation of HIF-1. HIF-1-induced expression of CAIX increases hepatocyte tolerance to ischemia by maintaining intracellular Na+ homeostasis. These observations along with the importance of HIF-1 in regulating cell survival indicates HIF-1 activation as a possible key event in liver protection by late preconditioning.


Asunto(s)
Adenosina/metabolismo , Hepatocitos/fisiología , Factor 1 Inducible por Hipoxia/metabolismo , Precondicionamiento Isquémico , Hígado/irrigación sanguínea , Receptor de Adenosina A2A/metabolismo , Receptores Purinérgicos P1/metabolismo , Adenosina/análogos & derivados , Adenosina/farmacología , Agonistas del Receptor de Adenosina A2 , Animales , Transporte Biológico , Anhidrasa Carbónica IV/metabolismo , Hipoxia de la Célula/fisiología , Núcleo Celular/metabolismo , Células Cultivadas , Medio de Cultivo Libre de Suero , Citoprotección , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Masculino , Fenetilaminas/farmacología , Agonistas del Receptor Purinérgico P1 , Ratas , Ratas Wistar , Factores de Tiempo
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