RESUMO
Tuberculosis (TB) is one of the deadliest infectious diseases in humankind history. Although, drug sensible TB is slowly decreasing, at present the rise of TB cases produced by multidrug-resistant (MDR) and extensively drug-resistant strains is a big challenge. Thus, looking for new therapeutic options against these MDR strains is mandatory. In the present work, we studied, in BALB/c mice infected with MDR strain, the therapeutic effect of supra-pharmacological doses of the conventional primary antibiotics rifampicin and isoniazid (administrated by gavage or intratracheal routes), in combination with recombinant human hepatocyte growth factor (HGF). This high dose of antibiotics administered for 3 months, overcome the resistant threshold of the MDR strain producing a significant reduction of pulmonary bacillary loads but induced liver damage, which was totally prevented by the administration of HGF. To address the long-term efficiency of this combined treatment, groups of animals after 1 month of treatment termination were immunosuppressed by glucocorticoid administration and, after 1 month, mice were euthanized, and the bacillary load was determined in lungs. In comparison with animals treated only with a high dose of antibiotics, animals that received the combined treatment showed significantly lower bacterial burdens. Thus, treatment of MDR-TB with very high doses of primary antibiotics particularly administrated by aerial route can produce a very good therapeutic effect, and its hepatic toxicity can be prevented by the administration of HGF, becoming in a new treatment modality for MDR-TB.
Assuntos
Antibióticos Antituberculose/toxicidade , Antioxidantes/farmacologia , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Fator de Crescimento de Hepatócito/farmacologia , Tuberculose Resistente a Múltiplos Medicamentos , Animais , Quimioterapia Combinada , Humanos , Isoniazida/toxicidade , Fígado/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Mycobacterium tuberculosis , Rifampina/toxicidadeRESUMO
Acute pancreatitis is a multifactorial disease associated with profound changes of the pancreas induced by release of digestive enzymes that lead to increase in proinflammatory cytokine production, excessive tissue necrosis, edema, and bleeding. Elevated levels of hepatocyte growth factor (HGF) and its receptor c-Met have been observed in different chronic and acute pancreatic diseases including experimental models of acute pancreatitis. In the present study, we investigated the protective effects induced by the recombinant human HGF in a mouse model of cerulein-induced acute pancreatitis. Pancreatitis was induced by 8 hourly administrations of supramaximal cerulein injections (50 µg/kg, ip). HGF treatment (20 µg/kg, iv), significantly attenuated lipase content and amylase activity in serum as well as the degree inflammation and edema overall leading to less severe histologic changes such as necrosis, induced by cerulein. Protective effects of HGF were associated with activation of pro-survival pathways such as Akt, Erk1/2, and Nrf2 and increase in executor survival-related proteins and decrease in pro-apoptotic proteins. In addition, ROS content and lipid peroxidation were diminished, and glutathione synthesis increased in pancreas. Systemic protection was observed by lung histology. In conclusion, our data indicate that HGF exerts an Nrf2 and glutathione-mediated protective effect on acute pancreatitis reflected by a reduction in inflammation, edema, and oxidative stress.
Assuntos
Fator de Crescimento de Hepatócito/uso terapêutico , Pancreatite/tratamento farmacológico , Substâncias Protetoras/uso terapêutico , Proteínas Recombinantes/uso terapêutico , Animais , Antioxidantes/metabolismo , Apoptose/efeitos dos fármacos , Ceruletídeo , Modelos Animais de Doenças , Glutationa/biossíntese , Fator de Crescimento de Hepatócito/sangue , Fator de Crescimento de Hepatócito/farmacologia , Humanos , Masculino , Camundongos , Estresse Oxidativo/efeitos dos fármacos , Pancreatite/patologia , Substâncias Protetoras/farmacologia , Proteínas Proto-Oncogênicas c-met/metabolismo , Proteínas Recombinantes/farmacologia , Transdução de Sinais/efeitos dos fármacos , Análise de SobrevidaRESUMO
Cholesterol overload in the liver has shown toxic effects by inducing the aggravation of nonalcoholic fatty liver disease to steatohepatitis and sensitizing to damage. Although the mechanism of damage is complex, it has been demonstrated that oxidative stress plays a prominent role in the process. In addition, we have proved that hepatocyte growth factor induces an antioxidant response in hepatic cells; in the present work we aimed to figure out the protective effect of this growth factor in hepatocytes overloaded with free cholesterol. Hepatocytes from mice fed with a high-cholesterol diet were treated or not with HGF, reactive oxygen species present in cholesterol overloaded hepatocytes significantly decreased, and this effect was particularly associated with the increase in glutathione and related enzymes, such as γ-gamma glutamyl cysteine synthetase, GSH peroxidase, and GSH-S-transferase. Our data clearly indicate that HGF displays an antioxidant response by inducing the glutathione-related protection system.
Assuntos
Colesterol/toxicidade , Fator de Crescimento de Hepatócito/sangue , Hepatócitos/metabolismo , Hepatócitos/patologia , Estresse Oxidativo/efeitos dos fármacos , Animais , Antioxidantes/metabolismo , Estudos de Casos e Controles , Células Cultivadas , Dieta , Ensaio de Imunoadsorção Enzimática , Glutationa/metabolismo , Hepatócitos/efeitos dos fármacos , Humanos , Fígado/efeitos dos fármacos , Fígado/patologia , Masculino , Camundongos , Hepatopatia Gordurosa não Alcoólica/sangue , Hepatopatia Gordurosa não Alcoólica/patologia , Proteínas Proto-Oncogênicas c-met/sangue , Espécies Reativas de Oxigênio/metabolismoRESUMO
Obesity and alcohol consumption are risk factors for hepatic steatosis, and both commonly coexist. Our objective was to evaluate the effect of ethanol and acetaldehyde on primary hepatocytes obtained from mice fed for two days with a high cholesterol (HC) diet. HC hepatocytes increased lipid and cholesterol content. HC diet sensitized hepatocytes to the toxic effect of ethanol and acetaldehyde. Cyp2E1 content increased with HC diet, as well as in those treated with ethanol or acetaldehyde, while the activity of this enzyme determined in microsomes increased in the HC and in all ethanol treated hepatocytes, HC and CW. Oxidized proteins were increased in the HC cultures treated or not with the toxins. Transmission electron microscopy showed endoplasmic reticulum (ER) stress and megamitochondria in hepatocytes treated with ethanol as in HC and the ethanol HC treated hepatocytes. ER stress determined by PERK content was increased in ethanol treated hepatocytes from HC mice and CW. Nuclear translocation of ATF6 was observed in HC hepatocytes treated with ethanol, results that indicate that lipids overload and ethanol treatment favor ER stress. Oxidative stress, ER stress, and mitochondrial damage underlie potential mechanisms for increased damage in steatotic hepatocyte treated with ethanol.
Assuntos
Acetaldeído/toxicidade , Colesterol/farmacologia , Etanol/toxicidade , Hepatócitos/patologia , Animais , Forma Celular/efeitos dos fármacos , Células Cultivadas , Citocromo P-450 CYP2E1/metabolismo , Dieta Hiperlipídica , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Lipídeos/química , Masculino , Camundongos Endogâmicos C57BL , Estresse Oxidativo/efeitos dos fármacosRESUMO
The increment in the prevalence of obesity incidence in Mexico is leading to the increase in many chronic maladies, including liver diseases. It is well known that lipid-induced liver sensitization is related to the kind of lipid rather than the amount of them in the organ. Cholesterol overload in the liver aggravates the toxic effects of canonical liver insults. However, the status on the repair and survival response elicited by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and the hepatocyte growth factor (HGF) is not completely understood. In the present, work we aimed to figure out the HGF/NADPH oxidase-induced cellular protection in the hepatocyte with a cholesterol overload. Our results show that a hypercholesterolemic diet induced liver damage and steatosis in mice. The hepatocytes isolated from these animals exhibited an increase in basal NADPH oxidase activity, although transcriptional levels of some of its components were decreased. No effect on the oxidase activity was observed in HGF treatments. The protective effect of HGF was abrogated as a result of cholesterol cellular overload, calculated by a survival assay. In conclusion, the cholesterol overload in hepatocytes impairs the HGF/NADPH oxidase-induced cellular protection.
Assuntos
Colesterol/metabolismo , Fator de Crescimento de Hepatócito/fisiologia , Hepatócitos/metabolismo , NADPH Oxidases/fisiologia , Animais , Masculino , Camundongos , Camundongos Endogâmicos C57BLRESUMO
In recent years, there has been a growing interest to explore the responsiveness to injury in steatotic hepatocyte. VL-17A cells, which express ADH and Cyp2E1 overloaded with free fatty acids (1 mM of oleic and palmitic acid 2:1) showed an increased oxidative damaged after 24 h free fatty acids treatment when exposed to ethanol (100 mM) for 48 h as a second injury. An increment in reactive oxygen species, determined by DCFH-DA, protein oxidation, and apoptosis were observed although an increase in main antioxidant proteins such as superoxide dismutase 1 and glutathione peroxidase were observed, but failed in gamma-glutamylcysteine synthetase, suggesting a decreased capacity of synthesis of glutathione compared with cells treated only with free fatty acids or ethanol. The increased oxidative stress and toxicity in lipid overloaded VL-17A cells subjected to ethanol exposure were accompanied by increases in Cyp2E1 protein expression. Our data show that lipid loaded in an in vitro model, VL-17A cells, is more susceptible to cell damage and oxidative stress when treated with ethanol.
Assuntos
Etanol/toxicidade , Ácidos Graxos não Esterificados/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Álcool Desidrogenase/metabolismo , Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Citocromo P-450 CYP2E1/genética , Citocromo P-450 CYP2E1/metabolismo , Fluoresceínas/metabolismo , Glutamato-Cisteína Ligase/metabolismo , Glutationa/biossíntese , Células Hep G2 , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Humanos , Espécies Reativas de Oxigênio/metabolismo , Triglicerídeos/metabolismoRESUMO
Alcohol is undoubtedly, the main toxic agent that people consume by recreation and the abuse is associated with liver damage, mainly by the overproduction of reactive oxygen species and the toxic effects of its first metabolite acetaldehyde. It is known that acetaldehyde targets mitochondria inducing redox imbalance and oxidative stress. Mitochondrial superoxide dismutase transforms superoxide radical into hydrogen peroxide, which in addition, is transformed in water by other enzymes. In the present study we demonstrate that acetaldehyde transiently impairs SOD2 activity in HepG2 cells, the decrease in the enzyme activity was associated to a reduction in the protein content, which was rapidly recovered, to basal values, by synthesis de novo in a mechanism mediated by NF-κB and PKC. The SOD2 impairment was not associated with adduct formation. The recovery on SOD2 activity in HepG2 cells can represent survival advantage for cancer cells, the results shown that SOD2 could be considered a therapeutic target in liver cancer.
Assuntos
Acetaldeído/farmacologia , Células Hep G2/efeitos dos fármacos , Superóxido Dismutase/metabolismo , Células Hep G2/metabolismo , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Terapia de Alvo Molecular , NF-kappa B/metabolismo , Proteína Quinase C/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase-1RESUMO
Statins are a group of extremely successful drugs that lower cholesterol levels in blood; decreasing the risk of heath attack or stroke. In recent years, statins have also been reported to have other biological activities and numerous potential therapeutic uses. Natural statins are lovastatin and compactin, while pravastatin is derived from the latter by biotransformation. Simvastatin, the second leading statin in the market, is a lovastatin semisynthetic derivative. Lovastatin is mainly produced by Aspergillus terreus strains, and compactin by Penicillium citrinum. Lovastatin and compactin are produced industrially by liquid submerged fermentation, but can also be produced by the emerging technology of solid-state fermentation, that displays some advantages. Advances in the biochemistry and genetics of lovastatin have allowed the development of new methods for the production of simvastatin. This lovastatin derivative can be efficiently synthesized from monacolin J (lovastatin without the side chain) by a process that uses the Aspergillus terreus enzyme acyltransferase LovD. In a different approach, A. terreus was engineered, using combinational biosynthesis on gene lovF, so that the resulting hybrid polyketide synthase is able to in vivo synthesize 2,2-dimethylbutyrate (the side chain of simvastatin). The resulting transformant strains can produce simvastatin (instead of lovastatin) by direct fermentation.