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1.
J Cell Mol Med ; 21(10): 2344-2358, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28374452

RESUMO

The intent of this study was to examine the effects of regulating cortisol levels on damage and regeneration in livers with and without steatosis subjected to partial hepatectomy under ischaemia-reperfusion. Ultimately, we found that lean animals undergoing liver resection displayed no changes in cortisol, whereas cortisol levels in plasma, liver and adipose tissue were elevated in obese animals undergoing such surgery. Such elevations were attributed to enzymatic upregulation, ensuring cortisol production, and downregulation of enzymes controlling cortisol clearance. In the absence of steatosis, exogenous cortisol administration boosted circulating cortisol, while inducing clearance of hepatic cortisol, thus maintaining low cortisol levels and preventing related hepatocellular harm. In the presence of steatosis, cortisol administration was marked by a substantial rise in intrahepatic availability, thereby exacerbating tissue damage and regenerative failure. The injurious effects of cortisol were linked to high hepatic acethylcholine levels. Upon administering an α7 nicotinic acethylcholine receptor antagonist, no changes in terms of tissue damage or regenerative lapse were apparent in steatotic livers. However, exposure to an M3 muscarinic acetylcholine receptor antagonist protected livers against damage, enhancing parenchymal regeneration and survival rate. These outcomes for the first time provide new mechanistic insight into surgically altered steatotic livers, underscoring the compelling therapeutic potential of cortisol-acetylcholine-M3 muscarinic receptors.


Assuntos
Fígado Gorduroso/cirurgia , Hepatectomia/métodos , Hidrocortisona/análise , Fígado/cirurgia , Acetilcolina/metabolismo , Acetilcolina/farmacologia , Tecido Adiposo/metabolismo , Animais , Agonistas Colinérgicos/metabolismo , Agonistas Colinérgicos/farmacologia , Fígado Gorduroso/sangue , Fígado Gorduroso/metabolismo , Hidrocortisona/sangue , Hidrocortisona/farmacologia , Fígado/metabolismo , Fígado/fisiopatologia , Regeneração Hepática/efeitos dos fármacos , Obesidade/sangue , Obesidade/metabolismo , Ratos , Traumatismo por Reperfusão/sangue , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/fisiopatologia
2.
Clin Sci (Lond) ; 131(8): 733-746, 2017 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-28246131

RESUMO

In the present study, we examined the effects of cortisol on steatotic and non-steatotic liver grafts from brain-dead donors and characterized the underlying mechanisms involved. Non-steatotic liver grafts showed reduced cortisol and increased cortisone levels in association with up-regulation of enzymes that inactivate cortisol. Conversely, steatotic liver grafts exhibited increased cortisol and reduced cortisone levels. The enzymes involved in cortisol generation were overexpressed, and those involved in cortisol inactivation or clearance were down-regulated in steatotic liver grafts. Exogenous administration of cortisol negatively affected hepatic damage and survival rate in non-steatotic liver transplantation (LT); however, cortisol treatment up-regulated the phosphoinositide 3-kinase (PI3K)-protein kinase C (PKC) pathway, resulting in protection against the deleterious effects of brain-dead donors on damage and inflammatory response in steatotic LT as well as in increased survival of recipients. The present study highlights the differences in the role of cortisol and hepatic mechanisms that regulate cortisol levels based on the type of liver. Our findings suggest that cortisol treatment is a feasible and highly protective strategy to reduce the adverse effects of brain-dead donor livers in order to ultimately improve liver graft quality in the presence of steatosis, whereas cortisol treatment would not be recommended for non-steatotic liver grafts.


Assuntos
Fígado Gorduroso/metabolismo , Hidrocortisona/uso terapêutico , Transplante de Fígado/métodos , Hormônio Adrenocorticotrópico/sangue , Animais , Glicemia/metabolismo , Morte Encefálica , Cortisona/metabolismo , Avaliação Pré-Clínica de Medicamentos/métodos , Fígado Gorduroso/patologia , Hidrocortisona/metabolismo , Hidrocortisona/farmacologia , Fígado/metabolismo , Fígado/patologia , Hepatopatias/etiologia , Hepatopatias/patologia , Hepatopatias/prevenção & controle , Transplante de Fígado/efeitos adversos , Fosfatidilinositol 3-Quinase/biossíntese , Proteína Quinase C/biossíntese , Ratos Zucker , Transdução de Sinais/efeitos dos fármacos , Taxa de Sobrevida , Síndrome de Resposta Inflamatória Sistêmica/etiologia , Síndrome de Resposta Inflamatória Sistêmica/patologia , Síndrome de Resposta Inflamatória Sistêmica/prevenção & controle , Regulação para Cima/efeitos dos fármacos
3.
J Hepatol ; 62(1): 83-91, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25111175

RESUMO

BACKGROUND & AIMS: Most liver grafts undergoing transplantation derive from brain dead donors, which may also show hepatic steatosis, being both characteristic risk factors in liver transplantation. Ischemic preconditioning shows benefits when applied in non-brain dead clinical situations like hepatectomies, whereas it has been less promising in the transplantation from brain dead patients. This study examined how brain death affects preconditioned steatotic and non-steatotic liver grafts undergoing transplantation. METHODS: Steatotic and non-steatotic grafts from non-brain dead and brain dead-donors were cold stored for 6h and then transplanted. After 2, 4, and 16 h of reperfusion, hepatic damage was analysed. In addition, two therapeutic strategies, ischemic preconditioning and/or acetylcholine pre-treatment, and their underlying mechanisms were characterized. RESULTS: Preconditioning benefits in non-brain dead donors were associated with nitric oxide and acetylcholine generation. In brain dead donors, preconditioning generated nitric oxide but did not promote acetylcholine upregulation, and this resulted in inflammation and damage. Acetylcholine treatment in brain dead donors, through PKC, increased antioxidants and reduced lipid peroxidation, nitrotyrosines and neutrophil accumulation, altogether protecting against damage. The combination of acetylcholine and preconditioning conferred stronger protection against damage, oxidative stress and neutrophil accumulation than acetylcholine treatment alone. These superior beneficial effects were due to a selective preconditioning-mediated generation of nitric oxide and regulation of PPAR and TLR4 pathways, which were not observed when acetylcholine was administered alone. CONCLUSIONS: Our findings propose the combination of acetylcholine+preconditioning as a feasible and highly protective strategy to reduce the adverse effects of brain death and to ultimately improve liver graft quality.


Assuntos
Morte Encefálica , Fígado Gorduroso/cirurgia , Precondicionamento Isquêmico/métodos , Transplante de Fígado , Estresse Oxidativo , Animais , Modelos Animais de Doenças , Fígado Gorduroso/metabolismo , Fígado Gorduroso/patologia , Ratos , Ratos Zucker
4.
Hepatology ; 59(4): 1505-13, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24037970

RESUMO

UNLABELLED: Type-1 hepatorenal syndrome (HRS) is a common complication of bacterial infections in cirrhosis, but its natural history remains undefined. To assess the outcome of kidney function and survival of patients with type-1 HRS associated with infections, 70 patients diagnosed during a 6-year period were evaluated prospectively. Main outcomes were no reversibility of type-1 HRS during treatment of the infection and 3-month survival. Forty-seven (67%) of the 70 patients had no reversibility of type-1 HRS during treatment of the infection. [Correction to previous sentence added March 10, 2014, after first online publication: "Twenty-three (33%)" was changed to "Forty-seven (67%)."] The main predictive factor of no reversibility of type-1 HRS was absence of infection resolution (no reversibility: 96% versus 48% in patients without and with resolution of the infection; P < 0.001). Independent predictive factors of no reversibility of type-1 HRS were age, high baseline serum bilirubin, nosocomial infection, and reduction in serum creatinine <0.3 mg/dL at day 3 of antibiotic treatment. No reversibility was also associated with severity of circulatory dysfunction, as indicated by more marked activity of the vasoconstrictor systems. In the whole series, 3-month probability of survival was only 21%. Factors associated with poor prognosis were baseline serum bilirubin, no reversibility of type-1 HRS, lack of resolution of the infection, and development of septic shock after diagnosis of type-1 HRS. CONCLUSION: Type-1 HRS associated with infections is not reversible in two-thirds of patients with treatment of infection only. No reversibility of type-1 HRS is associated with lack of resolution of the infection, age, high bilirubin, and no early improvement of kidney function and implies a poor prognosis. These results may help advance the management of patients with type-1 HRS associated with infections.


Assuntos
Infecções Bacterianas/complicações , Síndrome Hepatorrenal/etiologia , Síndrome Hepatorrenal/mortalidade , Rim/fisiopatologia , Cirrose Hepática/complicações , Cirrose Hepática/microbiologia , Adulto , Fatores Etários , Idoso , Antibacterianos/uso terapêutico , Infecções Bacterianas/tratamento farmacológico , Bilirrubina/sangue , Creatinina/sangue , Gerenciamento Clínico , Feminino , Seguimentos , Síndrome Hepatorrenal/fisiopatologia , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Estudos Retrospectivos , Taxa de Sobrevida , Resultado do Tratamento
5.
J Hepatol ; 60(1): 87-95, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23968888

RESUMO

BACKGROUND & AIMS: This study examined whether the regulation of resistin and visfatin could reduce damage and improve regeneration in both steatotic and non-steatotic livers undergoing partial hepatectomy under ischemia-reperfusion, a procedure commonly applied in clinical practice to reduce bleeding. METHODS: Resistin and visfatin were pharmacologically modulated in lean and obese animals undergoing partial hepatectomy under ischemia-reperfusion. RESULTS: No evident role for these adipocytokines was observed in non-steatotic livers. However, obese animals undergoing liver surgery showed increased resistin in liver and plasma, without changes in adipose tissue, together with visfatin downregulation in liver and increment in plasma and adipose tissue. Endogenous resistin maintains low levels of visfatin in the liver by blocking its hepatic uptake from the circulation, thus regulating the visfatin detrimental effects on hepatic damage and regenerative failure. Indeed, the administration of anti-resistin antibodies increased hepatic accumulation of adipocyte-derived visfatin, exacerbating damage and regenerative failure. Interestingly, treatment with anti-visfatin antibodies protected steatotic livers, and similar results were obtained with the concomitant inhibition of resistin and visfatin. Thus, when visfatin was inhibited, the injurious effects of anti-resistin antibodies disappeared. Herein we show that upregulation of visfatin increased NAD levels in the remnant steatotic liver, whereas visfatin inhibition decreased them. These later observations suggest that visfatin may favour synthesis of NAD instead of DNA and induces alterations in amino acid metabolism-urea cycle and NO production, overall negatively affecting liver viability. CONCLUSIONS: Our results indicate the clinical potential of visfatin blocking-based therapies in steatotic livers undergoing partial hepatectomy with ischemia-reperfusion.


Assuntos
Citocinas/fisiologia , Fígado Gorduroso/fisiopatologia , Regeneração Hepática/fisiologia , Fígado/metabolismo , Nicotinamida Fosforribosiltransferase/fisiologia , Resistina/fisiologia , Animais , Citocinas/antagonistas & inibidores , Hepatectomia , Masculino , NAD/metabolismo , Nicotinamida Fosforribosiltransferase/antagonistas & inibidores , Ratos , Ratos Wistar , Ratos Zucker , Reperfusão , Resistina/antagonistas & inibidores
6.
Liver Int ; 34(7): e271-89, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24107124

RESUMO

BACKGROUND: Steatosis is a risk factor in partial hepatectomy (PH) under ischaemia-reperfusion (I/R), which is commonly applied in clinical practice to reduce bleeding. Nutritional support strategies, as well as the role of peripheral adipose tissue as energy source for liver regeneration, remain poorly investigated. AIMS: To investigate whether the administration of either glucose or a lipid emulsion could protect steatotic and non-steatotic livers against damage and regenerative failure in an experimental model of PH under I/R. The relevance of peripheral adipose tissue in liver regeneration following surgery is studied. METHODS: Steatotic and non-steatotic rat livers were subjected to surgery and the effects of either glucose or lipid treatment on damage and regeneration, and part of the underlying mechanisms, were investigated. RESULTS: In non-steatotic livers, treatment with lipids or glucose provided the same protection against damage, regeneration failure and ATP drop. Adipose tissue was not required to regenerate non-steatotic livers. In the presence of hepatic steatosis, lipid treatment, but not glucose, protected against damage and regenerative failure by induction of cell cycle, maintenance of ATP levels and elevation of sphingosine-1-phosphate/ceramide ratio and phospholipid levels. Peripheral adipose tissue was required for regenerating the steatotic liver but it was not used as an energy source. CONCLUSION: Lipid treatment in non-steatotic livers provides the same protection as that afforded by glucose in conditions of PH under I/R, whereas the treatment with lipids is preferable to reduce the injurious effects of liver surgery in the presence of steatosis.


Assuntos
Fígado Gorduroso/metabolismo , Glucose/farmacologia , Hepatectomia/efeitos adversos , Isquemia/metabolismo , Lipídeos/farmacologia , Reperfusão , Trifosfato de Adenosina/metabolismo , Análise de Variância , Animais , Ceramidas , Fígado Gorduroso/tratamento farmacológico , Fígado Gorduroso/cirurgia , Glucose/metabolismo , Isquemia/etiologia , Fígado/efeitos dos fármacos , Fígado/fisiologia , Lisofosfolipídeos , Ratos , Regeneração/efeitos dos fármacos , Regeneração/fisiologia , Esfingosina/análogos & derivados
7.
J Hepatol ; 59(6): 1208-14, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23867317

RESUMO

BACKGROUND & AIMS: Numerous steatotic livers are discarded for transplantation because of their poor tolerance to ischemia-reperfusion. Controversial roles for adiponectin and related adipocytokines visfatin and resistin have been described in different liver pathologies, nevertheless it is unknown their possible implication in ischemia-reperfusion injury associated with liver transplantation. Our study aimed at characterizing the role of the adiponectin-derived molecular pathway in transplantation with steatotic and non-steatotic liver grafts. METHODS: Steatotic and non-steatotic liver transplantation was carried out and the hepatic levels of adiponectin, visfatin and resistin were measured and modulated either pharmacologically or surgically. RESULTS: Steatotic liver grafts exhibited downregulation of both adiponectin and resistin when subjected to transplantation. Adiponectin pre-treatment only protected steatotic grafts and did it so through a visfatin-independent and resistin-dependent mechanism. Adiponectin-derived resistin accumulation activated the PI3K/Akt pathway, unravelling AMPK as an upstream mediator of adiponectin's actions in steatotic grafts. Strategies aimed at increasing adiponectin including either AMPK activators or the induction of ischemic preconditioning (which activates AMPK) increased resistin accumulation, prevented the downregulation of PI3K/Akt pathway and protected steatotic liver grafts. Conversely, PI3K/Akt pathway upregulation and hepatic protection induced by adiponectin were abolished when resistin action was inhibited. CONCLUSIONS: Our findings reveal a new protective pathway in steatotic liver transplantation, namely AMPK-adiponectin-resistin-PI3K/Akt, which may help develop new strategies aimed at increasing either adiponectin or resistin in the steatotic liver undergoing transplant to ultimately increase organ donor pool and reduce waiting list.


Assuntos
Adiponectina/fisiologia , Fígado Gorduroso/cirurgia , Transplante de Fígado , Resistina/fisiologia , Proteínas Quinases Ativadas por AMP/fisiologia , Animais , Citocinas/fisiologia , Nicotinamida Fosforribosiltransferase/fisiologia , Fosfatidilinositol 3-Quinases/fisiologia , Proteínas Proto-Oncogênicas c-akt/fisiologia , Ratos , Ratos Zucker , Transdução de Sinais
9.
Liver Transpl ; 18(10): 1198-208, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22685091

RESUMO

Steatotic livers show increased hepatic damage and impaired regeneration after partial hepatectomy (PH) under ischemia/reperfusion (I/R), which is commonly applied in clinical practice to reduce bleeding. The known function of retinol-binding protein 4 (RBP4) is to transport retinol in the circulation. We examined whether modulating RBP4 and/or retinol could protect steatotic and nonsteatotic livers in the setting of PH under I/R. Steatotic and nonsteatotic livers from Zucker rats were subjected to PH (70%) with 60 minutes of ischemia. RBP4 and retinol levels were measured and altered pharmacologically, and their effects on hepatic damage and regeneration were studied after reperfusion. Decreased RBP4 levels were observed in both liver types, whereas retinol levels were reduced only in steatotic livers. RBP4 administration exacerbated the negative consequences of liver surgery with respect to damage and liver regeneration in both liver types. RBP4 affected the mobilization of retinol from steatotic livers, and this revealed actions of RBP4 independent of simple retinol transport. The injurious effects of RBP4 were not due to changes in retinol levels. Treatment with retinol was effective only for steatotic livers. Indeed, retinol increased hepatic injury and impaired liver regeneration in nonsteatotic livers. In steatotic livers, retinol reduced damage and improved regeneration after surgery. These benefits of retinol were associated with a reduced accumulation of hepatocellular fat. Thus, strategies based on modulating RBP4 could be ineffective and possibly even harmful in both liver types in the setting of PH under I/R. In terms of clinical applications, a retinol pretreatment might open new avenues for liver surgery that specifically benefit the steatotic liver.


Assuntos
Fígado Gorduroso/metabolismo , Hepatectomia/métodos , Isquemia/complicações , Fígado/metabolismo , Reperfusão/efeitos adversos , Proteínas Plasmáticas de Ligação ao Retinol/metabolismo , Vitamina A/metabolismo , Animais , Modelos Animais de Doenças , Fígado Gorduroso/cirurgia , Fígado/irrigação sanguínea , Fígado/cirurgia , Regeneração Hepática/efeitos dos fármacos , Masculino , Ratos , Ratos Zucker , Traumatismo por Reperfusão/etiologia , Traumatismo por Reperfusão/prevenção & controle , Proteínas Plasmáticas de Ligação ao Retinol/farmacologia , Fatores de Tempo , Vitamina A/farmacologia , Vitamina A/uso terapêutico
10.
Liver Transpl ; 17(9): 1099-110, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21671350

RESUMO

Numerous steatotic livers are discarded as unsuitable for transplantation (TR) because of their poor tolerance of ischemia/reperfusion (I/R). Cyclic adenosine 3',5'-monophosphate (cAMP)-elevating agents protect against I/R injury both in nonsteatotic livers that have been removed from non-heart-beating donors and subjected to warm ischemia or cold ischemia (CIS) and in perfused, isolated livers. Ischemic preconditioning (PC), which is based on brief periods of I/R, protects steatotic liver grafts, but the mechanism that is responsible is poorly understood. This study examines the role of cAMP in the vulnerability shown by steatotic livers to TR-associated I/R injury and the benefits of PC in this situation. Steatotic livers with or without PC were transplanted into Zucker rats. The hepatic levels of cAMP were measured and altered pharmacologically. Our results indicate that the cAMP levels in the nonsteatotic liver grafts were similar to those found in a sham group. However, high cAMP levels were observed in steatotic liver grafts. The blockage of cAMP generation by adenylate cyclase inhibitor pre-treatment or PC had the following results: reduced hepatic injury and increased survival of steatotic graft recipients; greater preservation of adenosine triphosphate (ATP) and reduced lactate accumulation throughout CI. This blockade of cAMP by a nitric oxide-dependent mechanism protected steatotic liver grafts against oxidative stress and microvascular disorders after reperfusion. In conclusion, cAMP blocking-based strategies could protect patients against the inherent risk of steatotic liver failure after TR.


Assuntos
AMP Cíclico/metabolismo , Fígado Gorduroso/terapia , Transplante de Fígado/métodos , Animais , Fígado Gorduroso/patologia , Homozigoto , Ácido Hialurônico/química , Isquemia/patologia , Precondicionamento Isquêmico , Fígado/patologia , Estresse Oxidativo , Ratos , Ratos Zucker , Fatores de Tempo , Transaminases/metabolismo , Tirosina/análogos & derivados , Tirosina/química
11.
J Pharmacol Exp Ther ; 338(1): 143-53, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21487070

RESUMO

Numerous steatotic livers are discarded for transplantation because of their poor tolerance of ischemia-reperfusion (I/R). The injurious effects of retinol-binding protein 4 (RBP4) in various pathologies are well documented. RBP4 levels are reduced by peroxisome proliferator-activated receptor-γ (PPARγ) agonists. Strategies aimed at increasing PPARγ protect steatotic livers under warm ischemia. Ischemic preconditioning (PC) based on brief periods of I/R protects steatotic liver grafts against I/R injury, but the responsible mechanism is poorly understood. We examined the roles of RBP4 and PPARγ in I/R injury associated with steatotic liver transplantation and the benefits of PC in such situations. We report that RBP4 and PPARγ expression levels in nonsteatotic livers were similar to those found in the sham group. However, reduced RBP4 and increased PPARγ levels were observed in steatotic livers. Treatment with either RBP4 or a PPARγ antagonist was effective only in steatotic livers. PC, which increased RBP4 levels, and RBP4 treatment both reduced PPARγ levels and hepatic injury in steatotic livers. When PPARγ was activated, neither RBP4 treatment nor PC (despite RBP4 induction) protected steatotic livers. In conclusion, steatotic liver grafts are more predisposed to down-regulate RBP4 and overexpress PPARγ. RBP4 treatment and PC, through RBP4 induction, reduced PPARγ levels in steatotic liver grafts, thus protecting them from the PPARγ detrimental effects.


Assuntos
Fígado Gorduroso/metabolismo , Transplante de Fígado/fisiologia , PPAR gama/metabolismo , Proteínas Plasmáticas de Ligação ao Retinol/metabolismo , Animais , Regulação para Baixo/fisiologia , Fígado Gorduroso/patologia , Transplante de Fígado/métodos , PPAR gama/biossíntese , Ratos , Ratos Zucker , Proteínas Plasmáticas de Ligação ao Retinol/antagonistas & inibidores , Proteínas Plasmáticas de Ligação ao Retinol/biossíntese , Regulação para Cima/fisiologia
12.
Gastroenterology ; 140(2): 488-496.e4, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20682324

RESUMO

BACKGROUND & AIMS: The prognostic value of the different causes of renal failure in cirrhosis is not well established. This study investigated the predictive value of the cause of renal failure in cirrhosis. METHODS: Five hundred sixty-two consecutive patients with cirrhosis and renal failure (as defined by serum creatinine > 1.5 mg/dL on 2 successive determinations within 48 hours) hospitalized over a 6-year period in a single institution were included in a prospective study. The cause of renal failure was classified into 4 groups: renal failure associated with bacterial infections, renal failure associated with volume depletion, hepatorenal syndrome (HRS), and parenchymal nephropathy. The primary end point was survival at 3 months. RESULTS: Four hundred sixty-three patients (82.4%) had renal failure that could be classified in 1 of 4 groups. The most frequent was renal failure associated with infections (213 cases; 46%), followed by hypovolemia-associated renal failure (149; 32%), HRS (60; 13%), and parenchymal nephropathy (41; 9%). The remaining patients had a combination of causes or miscellaneous conditions. Prognosis was markedly different according to cause of renal failure, 3-month probability of survival being 73% for parenchymal nephropathy, 46% for hypovolemia-associated renal failure, 31% for renal failure associated with infections, and 15% for HRS (P < .0005). In a multivariate analysis adjusted for potentially confounding variables, cause of renal failure was independently associated with prognosis, together with MELD score, serum sodium, and hepatic encephalopathy at time of diagnosis of renal failure. CONCLUSIONS: A simple classification of patients with cirrhosis according to cause of renal failure is useful in assessment of prognosis and may help in decision making in liver transplantation.


Assuntos
Cirrose Hepática/complicações , Insuficiência Renal/diagnóstico , Insuficiência Renal/etiologia , Idoso , Infecções Bacterianas/complicações , Creatinina/sangue , Feminino , Síndrome Hepatorrenal/complicações , Humanos , Cirrose Hepática/cirurgia , Transplante de Fígado , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Insuficiência Renal/mortalidade , Sódio/sangue
13.
Liver Transpl ; 16(9): 1098-111, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20818748

RESUMO

This study examined the effects of epidermal growth factor (EGF) and insulin-like growth factor-I (IGF-I) supplementation to University of Wisconsin solution (UW) in steatotic and nonsteatotic livers during cold storage. Hepatic injury and function were evaluated in livers preserved for 24 hours at 4 degrees C in UW and in UW with EGF and IGF-I (separately or in combination) and then perfused ex vivo for 2 hours at 37 degrees C. AKT was inhibited pharmacologically. In addition, hepatic injury and survival were evaluated in recipients who underwent transplantation with steatotic and nonsteatotic livers preserved for 6 hours in UW and UW with EGF and IGF-I (separately or in combination). The results, based on isolated perfused liver, indicated that the addition of EGF and IGF-I (separately or in combination) to UW reduced hepatic injury and improved function in both liver types. A combination of EGF and IGF-I resulted in hepatic injury and function parameters in both liver types similar to those obtained by EGF and IGF-I separately. EGF increased IGF-I, and both additives up-regulated AKT in both liver types. This was associated with glycogen synthase kinase-3beta (GSK3(beta)) inhibition in nonsteatotic livers and PPAR gamma overexpression in steatotic livers. When AKT was inhibited, the effects of EGF and IGF-I on GSK3(beta), PPAR gamma, hepatic injury and function disappeared. The benefits of EGF and IGF-I as additives in UW solution were also clearly seen in the liver transplantation model, because the presence of EGF and IGF-I (separately or in combination) in UW solution reduced hepatic injury and improved survival in recipients who underwent transplantation with steatotic and nonsteatotic liver grafts. In conclusion, EGF and IGF-I may constitute new additives to UW solution in steatotic and nonsteatotic liver preservation, whereas a combination of both seems unnecessary.


Assuntos
Fator de Crescimento Epidérmico/farmacologia , Fígado Gorduroso/cirurgia , Fator de Crescimento Insulin-Like I/farmacologia , Transplante de Fígado , Fígado/efeitos dos fármacos , Fígado/cirurgia , Soluções para Preservação de Órgãos/farmacologia , Preservação de Órgãos/métodos , Traumatismo por Reperfusão/prevenção & controle , Adenosina/farmacologia , Alopurinol/farmacologia , Animais , Sobrevivência Celular , Isquemia Fria , Modelos Animais de Doenças , Fígado Gorduroso/patologia , Glutationa/farmacologia , Quinase 3 da Glicogênio Sintase/metabolismo , Glicogênio Sintase Quinase 3 beta , Insulina/farmacologia , Fígado/metabolismo , Fígado/patologia , Transplante de Fígado/efeitos adversos , PPAR gama/metabolismo , Perfusão , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/metabolismo , Rafinose/farmacologia , Ratos , Ratos Zucker , Proteínas Recombinantes/farmacologia , Traumatismo por Reperfusão/etiologia , Traumatismo por Reperfusão/patologia , Fatores de Tempo
14.
Liver Transpl ; 16(2): 163-71, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20104484

RESUMO

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 degrees 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.


Assuntos
Antagonistas Adrenérgicos beta/farmacologia , Carbazóis/farmacologia , Fígado Gorduroso/prevenção & controle , Transplante de Fígado , Soluções para Preservação de Órgãos/farmacologia , Preservação de Órgãos/métodos , Propanolaminas/farmacologia , Adenosina/farmacologia , Trifosfato de Adenosina/metabolismo , Adenilato Quinase/metabolismo , Alopurinol/farmacologia , Animais , Bile/metabolismo , Carvedilol , Temperatura Baixa , Glutationa/farmacologia , Insulina/farmacologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Testes de Função Hepática , Complicações Pós-Operatórias/prevenção & controle , Rafinose/farmacologia , Ratos , Ratos Zucker , Traumatismo por Reperfusão/prevenção & controle , Resistência Vascular/efeitos dos fármacos
15.
Endocrinology ; 150(7): 3153-61, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19282385

RESUMO

Hepatic steatosis is a major risk factor in ischemia-reperfusion (I/R). IGF-binding proteins (IGFBPs) modulate IGF-I action by transporting circulating IGF-I to its sites of action. Epidermal growth factor (EGF) stimulates IGF-I synthesis in vitro. We examined the effect of IGF-I and EGF treatment, separately or in combination, on the vulnerability of steatotic livers to I/R. Our results indicated that I/R impaired IGF-I synthesis only in steatotic livers. Only when a high dose of IGF-I (400 microg/kg) was given to obese animals did they show high circulating IGF-I:IGFBP levels, increased hepatic IGF-I levels, and protection against damage. In lean animals, a dose of 100 microg/kg IGF-I protected nonsteatotic livers. Our results indicated that the combined administration of IGF-I and EGF resulted in hepatic injury parameters in both liver types similar to that obtained by IGF-I and EGF separately. IGF-I increased egf expression in both liver types. The beneficial role of EGF on hepatic I/R injury may be attributable to p38 inhibition in nonsteatotic livers and to PPAR gamma overexpression in steatotic livers. In conclusion, IGF-I and EGF may constitute new pharmacological strategies to reduce the inherent susceptibility of steatotic livers to I/R injury.


Assuntos
Fator de Crescimento Epidérmico/uso terapêutico , Fígado Gorduroso/complicações , Fator de Crescimento Insulin-Like I/uso terapêutico , Traumatismo por Reperfusão/prevenção & controle , Animais , Fator de Crescimento Epidérmico/administração & dosagem , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/metabolismo , Fator de Crescimento Insulin-Like I/administração & dosagem , Fator de Crescimento Insulin-Like I/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , PPAR gama/fisiologia , Ratos , Ratos Zucker , Proteínas Quinases p38 Ativadas por Mitógeno/fisiologia
16.
J Pharmacol Exp Ther ; 329(1): 130-40, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19116369

RESUMO

We examined whether angiotensin (Ang) II receptor antagonists could be considered a therapeutic strategy in steatotic and nonsteatotic livers in conditions of partial hepatectomy under ischemia-reperfusion (I/R), which is commonly applied in clinical practice to reduce blood loss. We report that Ang II type I receptor (AT1R) antagonist, but not Ang II type II receptor (AT2R) antagonist, increased regeneration in nonsteatotic livers. In the presence of steatosis, both AT1R and AT2R antagonists increased liver regeneration. This effect was stronger when the two were combined. Neither of the Ang II receptor antagonists protected nonsteatotic livers against damage. Only the AT1R antagonist, through nitric oxide inhibition, reduced damage in steatotic livers. The combination of the AT1R and AT2R antagonists in steatotic livers conferred a similar degree of protection to AT1R antagonist alone. Herein, we show that p38 mitogen-activated protein kinase (p38) was a key mechanism in the regeneration induced by the Ang II receptor antagonists in both liver types because when this signaling pathway was inhibited, the beneficial effects of the Ang II receptor antagonists on liver regeneration disappeared, regardless of hepatocyte growth factor or transforming growth factor beta-hepatic levels. In conclusion, in conditions of partial hepatectomy under I/R, the AT1R antagonist for nonsteatotic livers and the AT1R and AT2R antagonists for steatotic livers improved regeneration in the remnant liver through p38 activation. In addition, the combination of the AT1R and AT2R antagonists in steatotic livers led to stronger liver regeneration than either antagonists used separately and also provided the same protection against damage as that afforded by AT1R antagonist alone.


Assuntos
Bloqueadores do Receptor Tipo 1 de Angiotensina II/farmacologia , Bloqueadores do Receptor Tipo 2 de Angiotensina II , Fígado Gorduroso/tratamento farmacológico , Hepatectomia , Fígado/patologia , Traumatismo por Reperfusão/tratamento farmacológico , Animais , Western Blotting , Proliferação de Células/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Fígado Gorduroso/patologia , Hepatócitos/efeitos dos fármacos , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase/antagonistas & inibidores , Obesidade/tratamento farmacológico , Obesidade/patologia , Ratos , Ratos Zucker , Receptor Tipo 1 de Angiotensina/genética , Receptor Tipo 2 de Angiotensina/genética , Traumatismo por Reperfusão/patologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
18.
Gastroenterology ; 134(5): 1352-9, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18471512

RESUMO

BACKGROUND & AIMS: Hepatorenal syndrome is common in patients with advanced cirrhosis and constitutes a major problem in liver transplantation. There is no effective medical treatment for hepatorenal syndrome. METHODS: Forty-six patients with cirrhosis and hepatorenal syndrome, hospitalized in a tertiary care center, were randomly assigned to receive either terlipressin (1-2 mg/4 hour, intravenously), a vasopressin analogue, and albumin (1 g/kg followed by 20-40 g/day) (n = 23) or albumin alone (n = 23) for a maximum of 15 days. Primary outcomes were improvement of renal function and survival at 3 months. RESULTS: Improvement of renal function occurred in 10 patients (43.5%) treated with terlipressin and albumin compared with 2 patients (8.7%) treated with albumin alone (P = .017). Independent predictive factors of improvement of renal function were baseline urine volume, serum creatinine and leukocyte count, and treatment with terlipressin and albumin. Survival at 3 months was not significantly different between the 2 groups (terlipressin and albumin: 27% vs albumin 19%, P = .7). Independent predictive factors of 3-month survival were baseline model for end-stage liver disease score and improvement of renal function. Cardiovascular complications occurred in 4 patients treated with albumin alone and in 10 patients treated with terlipressin and albumin, yet permanent terlipressin withdrawal was required in only 3 cases. CONCLUSIONS: As compared with albumin, treatment with terlipressin and albumin is effective in improving renal function in patients with cirrhosis and hepatorenal syndrome. Further studies with large sample sizes should be performed to test whether the improvement of renal function translates into a survival benefit.


Assuntos
Albuminas/administração & dosagem , Síndrome Hepatorrenal/tratamento farmacológico , Cirrose Hepática/tratamento farmacológico , Lipressina/análogos & derivados , Vasoconstritores/administração & dosagem , Adolescente , Adulto , Idoso , Relação Dose-Resposta a Droga , Quimioterapia Combinada , Feminino , Seguimentos , Síndrome Hepatorrenal/etiologia , Síndrome Hepatorrenal/mortalidade , Humanos , Injeções Intravenosas , Testes de Função Renal , Cirrose Hepática/complicações , Cirrose Hepática/mortalidade , Lipressina/administração & dosagem , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Choque Séptico , Taxa de Sobrevida/tendências , Terlipressina , Fatores de Tempo , Resultado do Tratamento , Estados Unidos/epidemiologia
20.
Crit Care Med ; 36(4): 1256-66, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18379253

RESUMO

OBJECTIVE: We examined whether pharmacologic strategies blocking angiotensin II actions protect steatotic livers against ischemia-reperfusion (I/R) injury. The effects of ischemic preconditioning (PC) on angiotensin II were also evaluated. DESIGN: Randomized and controlled animal study. SETTING: Experimental laboratory. SUBJECTS: Zucker rats. INTERVENTIONS: The following experimental groups were studied: I/R, ischemia-reperfusion + angiotensin-converting enzyme inhibitor (I/R+ACE inhibitor), ischemia-reperfusion + angiotensin II type I receptor antagonist (I/R+AT1R antagonist), ischemia-reperfusion + angiotensin II type II receptor antagonist (I/R+AT2R antagonist), and PC (5 mins of ischemia + 10 mins of reperfusion before I/R). In some of these groups, the action of bradykinin (BK) and/or peroxisome-proliferator-activated receptor-gamma (PPARgamma) was altered pharmacologically. MEASUREMENTS AND MAIN RESULTS: I/R+ACE inhibitor, I/R+AT1R antagonist, and I/R+AT2R antagonist reduced hepatic injury in steatotic livers compared with the I/R group. PC reduced angiotensin II generation and hepatic injury in steatotic livers in comparison to I/R group. Our results revealed that I/R+ACE inhibitor, I/R+AT1R antagonist, I/R+AT2R antagonist, and PC increased BK compared with the I/R group. In addition, the effects of PC on BK and hepatic injury were abolished when angiotensin II was administered. Furthermore, administration of BK receptor antagonists to the I/R+ACE inhibitor, I/R+AT1R antagonist, I/R+AT2R antagonist, and PC groups resulted in hepatic injury similar to the I/R group, indicating that the benefits of ACE inhibitor, AT1R antagonist, AT2R antagonist, and PC were abolished when the action of BK was inhibited. Experiments aimed at investigating why BK was protective in steatotic livers indicated that BK acts as a positive regulator of PPARgamma. If PPARgamma action was inhibited, BK did not protect steatotic livers against hepatic injury. CONCLUSIONS: Pharmacologic blockers of angiotensin II action (ACE inhibitors, AT1R antagonists, and AT2R antagonists) and PC, which reduced angiotensin II generation, increased BK generation in steatotic livers after I/R. This in turn increased PPARgamma and protected this type of liver against I/R injury.


Assuntos
Bloqueadores do Receptor Tipo 1 de Angiotensina II/uso terapêutico , Angiotensina II/antagonistas & inibidores , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Bradicinina/uso terapêutico , Fígado Gorduroso/metabolismo , Interleucina-10/uso terapêutico , Traumatismo por Reperfusão/prevenção & controle , Animais , Ratos , Ratos Zucker , Reação em Cadeia da Polimerase Via Transcriptase Reversa
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