RESUMO
The induction of leukemic cell differentiation is a hopeful therapeutic modality. We studied the effects of monochloramine (NH2Cl) on erythroleukemic K562 cell differentiation, and compared the effects observed with those of U0126 and staurosporine, which are known inducers of erythroid and megakaryocytic differentiation, respectively. CD235 (glycophorin) expression, a marker of erythroid differentiation, was significantly increased by NH2Cl and U0126, along with an increase in cd235 mRNA levels. Other erythroid markers such as γ-globin and CD71 (transferrin receptor) were also increased by NH2Cl and U0126. In contrast, CD61 (integrin ß3) and CD42b (GP1bα) expression, markers of megakaryocytic differentiation, was increased by staurosporine, but did not change significantly by NH2Cl and U0126. NH2Cl retarded cell proliferation without a marked loss of viability. When ERK phosphorylation (T202/Y204) and CD235 expression were compared using various chemicals, a strong negative correlation was observed (r = -0.76). Paradoxically, NH2Cl and staurosporine, but not U0126, induced large cells with multiple or lobulated nuclei, which was characteristic to megakaryocytes. NH2Cl increased the mRNA levels of gata1 and scl, decreased that of gata2, and did not change those of pu.1 and klf1. The changes observed in mRNA expression were different from those of U0126 or staurosporine. These results suggest that NH2Cl induces the bidirectional differentiation of K562. Oxidative stress may be effective in inducing leukemic cell differentiation.
Assuntos
Cloraminas/farmacologia , Leucemia Eritroblástica Aguda/tratamento farmacológico , Leucemia Eritroblástica Aguda/patologia , Megacariócitos/citologia , Butadienos/farmacologia , Técnicas de Cultura de Células , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Glicoforinas/biossíntese , Humanos , Integrina beta3/biossíntese , Células K562 , Leucemia Eritroblástica Aguda/metabolismo , Megacariócitos/efeitos dos fármacos , Megacariócitos/metabolismo , Nitrilas/farmacologia , Estresse Oxidativo , Fosforilação , Estaurosporina/farmacologiaRESUMO
Several lines of epidemiological studies have indicated that caffeine consumption and plasma uric acid (UA) level were negatively correlated with the incidence of some neurodegenerative diseases. We report here a novel mechanism by which these purine derivatives increase neuronal glutathione (GSH) synthesis. Intraperitoneal injection of caffeine or UA into male C57BL/6 mice significantly increased total GSH levels in the hippocampus. Neither SCH58261, an adenosine A2A receptor antagonist, nor rolipram, a phosphodiesterase-4 inhibitor, increased GSH levels. Pretreatment with allopurinol, a drug to inhibit UA production, did not change the GSH level in the caffeine-treated mice. Hippocampal CA1 pyramidal neurons treated with caffeine or UA were resistant to oxidant exposure in the slice culture experiments. In experiments with the SH-SY5Y cell line, cysteine uptake was sodium-dependent and pretreatment with caffeine or UA increased cysteine uptake significantly as compared with the control conditions. Slice culture experiments using the hippocampus also showed increased cysteine and GSH contents after the treatment with caffeine or UA. Immunohistochemical analysis showed increased GSH levels in the hippocampal excitatory amino acid carrier-1 (EAAC1)-positive neurons of mice treated with caffeine or UA. These findings suggest that purine derivatives caffeine and UA induce neuronal GSH synthesis by promoting cysteine uptake, leading to neuroprotection.
Assuntos
Cafeína/farmacologia , Glutationa/agonistas , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Ácido Úrico/farmacologia , Animais , Cafeína/uso terapêutico , Linhagem Celular Tumoral , Glutationa/biossíntese , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fármacos Neuroprotetores/uso terapêutico , Técnicas de Cultura de Órgãos , Estresse Oxidativo/fisiologia , Ácido Úrico/uso terapêuticoRESUMO
Compared to young patients with Takayasu's arteritis (TA), little information about elderly patients with TA has been reported. Additionally, no reports were found regarding TA cases with complications of intestinal amyloidosis. This is a case report of an elderly female, who developed intestinal amyloidosis, during late-stage TA. After years of outpatient management, she developed sudden severe dyspnea with pulmonary effusion, requiring hospitalization. After this event, betamethasone was replaced by methotrexate (MTX) for the next 34 months, but it seemed ineffective. After 1.5 years, she developed intractable diarrhea, followed by increases in BUN and serum creatinine (Cr), requiring several courses of hemodialysis. Colonoscopy revealed the presence of amyloid in her intestine, although she died of complicated sepsis caused by MRSA infection. This may be the first paper describing intestinal amyloidosis in a TA patient. Additionally, her case is rare in that she lived more than 30 years after the onset and diagnosis of TA.
Assuntos
Amiloidose/complicações , Enteropatias/complicações , Arterite de Takayasu/complicações , Idoso , Angiografia Digital , Evolução Fatal , Feminino , Humanos , Pneumopatias/diagnóstico por imagem , Pneumopatias/tratamento farmacológico , Pneumopatias/etiologia , Resistência a Meticilina , Metotrexato/uso terapêutico , Radiografia Torácica , Transtornos Respiratórios/diagnóstico por imagem , Transtornos Respiratórios/etiologia , Infecções Estafilocócicas/complicações , Infecções Estafilocócicas/microbiologia , Staphylococcus/fisiologia , Falha de TratamentoRESUMO
We examined the response of T lymphocytes activated with specific alloantigens following Fas-mediated apoptosis; using a mixed lymphocyte culture (MLC) system. Cells obtained from an MLC after 6 or 7 days of culture were incubated for are additional 24 hours in the presence or absence of the agonistic monoclonal antibody (MoAb), 7C11, or the antagonistic MoAb, ZB4. We assessed DNA fragmentation/specific cytotoxiy of the MoAb-treated cells. Cells harvested after 4 days of culture were sensitive to apoptosis induced by 7C11 with maximum DNA fragmentation observed on day 6. ZB4 slightly inhibited apoptosis of the cells compared with controls. The simultaneous addition of recombinant interleukin-2 (rIL-2) with the MoAbs significantly inhibited DNA fragmentation in control and ZB4-treated cells, but had little effect on the 7C11-treated cells. Control and ZB4-treated MLC cells showed cytotoxic activities against specific target cells, namely >10%. In contrast, the 7C11-treated cells showed <5% cytotoxicity. Although the addition of rIL-2 increased specific percentage cytotoxicity of control and ZB4-treated cells, it had little effect on the specific cytotoxic activity of the 7C11-treated MLC cells. These results suggest that specific cytotoxic T lymphocytes may be eliminated via apoptosis mediated by the Fas/Fas ligand system.
Assuntos
Isoantígenos/imunologia , Ativação Linfocitária/imunologia , Linfócitos T/imunologia , Receptor fas/imunologia , Adulto , Morte Celular/imunologia , Humanos , Valores de Referência , Linfócitos T/citologia , Linfócitos T Citotóxicos/imunologiaRESUMO
BACKGROUND: The roles of matrix metalloproteinases (MMPs) in cancer metastasis have been studied. Macrophages are considered to release MMPs in the tissues of patients with lung cancer. METHODS: Intracellular collagenase activity was measured in CD14+ CD45+ cells from bronchial lavage fluid to establish a new diagnostic tool for lung cancer. Between August 2000 and November 2001 bronchoscopy and bronchial lavage were performed in 45 patients with abnormal shadows on the chest radiograph; 21 had lung cancer and 24 had non-malignant disease. RESULTS: Collagenase activity in patients with primary lung cancer (5.54 (0.65)) or non-small cell lung cancer (NSCLC) (5.62 (0.71)) was significantly higher than in those with non-malignant disease (3.63 (0.78), p=0.006 and p=0.008, respectively). Only three of 18 patients in the low activity group were diagnosed as having cancer compared with 18 of 27 in the high activity group (p=0.001). This significance was not seen in non-smokers but it was apparent in smokers/ex-smokers. Excluding non-smokers improved the specificity of collagenase activity in differentiating cancer and non-malignant disease from 62.5% to 80.0%. The sensitivity of the test was 85.7% in all patients and 88.2% in smokers/ex-smokers. CONCLUSIONS: Measurement of intracellular collagenase activity in macrophages in bronchial lavage fluid is a useful diagnostic tool for distinguishing between cancer and non-malignant diseases, especially in smokers and ex-smokers.
Assuntos
Biomarcadores Tumorais/metabolismo , Líquido da Lavagem Broncoalveolar/citologia , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Colagenases/metabolismo , Neoplasias Pulmonares/diagnóstico , Macrófagos/enzimologia , Metaloproteinases da Matriz/metabolismo , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Proteína C-Reativa/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Fatores Sexuais , Fumar/metabolismoRESUMO
BACKGROUND: Apoptosis (programmed cell death) occurs in various physiological and pathological conditions, exhibits a characteristic mechanism of intracellular sequential reaction and may be involved in determining clinical outcome. The antioxidant activity of propofol (2,6-diisopropylphenol) together with the stimulating effect of protein kinase C suggests that propofol might have the potential to modulate apoptosis. Thus, it is of both clinical interest and biomedical importance to investigate and clarify the effect and mechanism of propofol upon the intracellular reactions underlying apoptotic cell death. METHODS: The effect of propofol on apoptosis was investigated using cultured human promyelocytic leukemia HL-60 cells. This well-characterized cell line is useful for the study of apoptosis because the various biochemical steps occurring during apoptosis have been well documented. RESULTS: Treatment of HL-60 cells with propofol resulted in growth inhibition with the formation of apoptotic bodies in a concentration-dependent manner. DNA fragmentation and ladder formation was also observed in a concentration-dependent manner. Propofol treatment resulted in activation of caspase-3, -6, -8 and -9, thereby suggesting that cell surface death receptor activation of the caspase cascade mediates propofol-induced apoptosis with consequent formation of the cleaved product of Bid (a pro-apoptotic Bcl-2 family member protein) and activation of the mitochondrial pathway with cytosolic release of cytochrome c. CONCLUSION: Propofol may induce apoptosis, which is dependent on the mechanism that activates both the cell surface death receptor pathway and the mitochondrial pathway.
Assuntos
Anestésicos Intravenosos/farmacologia , Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Propofol/farmacologia , Apoptose/fisiologia , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3 , Proteínas de Transporte/metabolismo , Caspases/metabolismo , Divisão Celular/efeitos dos fármacos , Grupo dos Citocromos c/metabolismo , Fragmentação do DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células HL-60 , Humanos , Fragmentos de Peptídeos/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismoRESUMO
Palmitoyl-CoA (Pal-CoA) lowered the respiratory control ratio (RCR), and induced mitochondrial membrane permeability transition (MPT) and cytochrome c (Cyt. c) release from isolated rat liver mitochondria. L-Carnitine suppressed the Pal-CoA-induced dysfunction, MPT, and Cyt. c release of isolated mitochondria. This suppression was inhibited by cephaloridine, an inhibitor of carnitine uptake into mitochondria. Cyclosporin A (CsA), an inhibitor of MPT, and BSA also suppressed the Pal-CoA-induced MPT. In the presence of inorganic phosphate (P(i)), Ca2+-induced MPT was suppressed by BSA, L-carnitine, and chlorpromazine, an inhibitor of phospholipase A2. In the presence of a low concentration of Ca2+, 3,3',5-triiodothyronine, long chain fatty acids, salicylic acid, and diclofenac induced MPT by a mechanism that was suppressed by BSA, L-carnitine, or chlorpromazine. During the incubation of mitochondria on ice, their respiratory competence decreased; L-carnitine and BSA also prevented this decrease. Mitochondrial depolarization in pheochromocytoma PC12 cells was induced by either serum deprivation or arachidonic acid by a mechanism that was suppressed by acetyl-L-carnitine. These results indicate that some MPTs may be regulated by fatty acid metabolism and that the Pal-CoA-induced MPT plays an important role in the induction of apoptosis.
Assuntos
Carnitina/farmacologia , Ácidos Graxos/farmacologia , Mitocôndrias Hepáticas/efeitos dos fármacos , Animais , Senescência Celular/efeitos dos fármacos , Cefaloridina/farmacologia , Cefalosporinas/farmacologia , Clorpromazina/farmacologia , Ciclosporina/farmacologia , Grupo dos Citocromos c/metabolismo , Antagonistas de Dopamina/farmacologia , Interações Medicamentosas , Inibidores Enzimáticos/farmacologia , Mitocôndrias Hepáticas/fisiologia , Dilatação Mitocondrial/efeitos dos fármacos , Células PC12 , Palmitoil Coenzima A/farmacologia , Permeabilidade/efeitos dos fármacos , Fosforilação , Ratos , Ratos Wistar , Soroalbumina Bovina/farmacologiaRESUMO
The biochemical properties and specificity of n-3 and n-6 polyunsaturated fatty acids (PUFAs) are not well known. Because PUFAs induce apoptosis of different cells, we studied the effect of various PUFAs, such as arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosapentaenoic acid (DPA), on the fate of cultured human promyelocytic leukemia cells (HL-60) to elucidate the mechanism of apoptosis and the difference in action between n-3 and n-6 PUFAs. Fairly low concentrations of PUFAs inhibited the growth of HL-60 cells and induced their apoptosis by a mechanism that is sensitive to DMSO, an antioxidant, and z-Val-Ala-Asp(OMe)-fluoromethylketone (z-VAD-fmk), a pan-caspase inhibitor. PUFAs stimulated the generation of reactive oxygen species (ROS) and activated various types of caspase-like proteases, such as caspase-3, -6, -8, and -9, but not caspase-1. In addition, PUFAs triggered the reaction leading to the cleavage of Bid, a death agonist member of the Bcl-2 family, and also released cytochrome c from mitochondria into the cytosol. PUFAs also decreased the mitochondrial membrane potential of intact HL-60 cells. All of these actions of n-3 PUFAs were stronger than those of AA, an n-6 PUFA, although the mechanism is not known. PUFAs stimulate swelling and membrane depolarization of isolated mitochondria in a cyclosporin A-sensitive manner. The results indicated that PUFA-induced apoptosis of HL-60 cells may be caused, in part, by direct action on the cells and by activation of the caspase cascade through cytochrome c release coupled with mitochondrial membrane depolarization.
Assuntos
Apoptose , Ácidos Graxos Insaturados/farmacologia , Células HL-60/efeitos dos fármacos , Triglicerídeos/farmacologia , Clorometilcetonas de Aminoácidos/farmacologia , Caspases/metabolismo , Diferenciação Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Inibidores de Cisteína Proteinase/farmacologia , Grupo dos Citocromos c/metabolismo , DNA/efeitos dos fármacos , DNA/metabolismo , Fragmentação do DNA/efeitos dos fármacos , Ácidos Graxos Ômega-3 , Ácidos Graxos Ômega-6 , Células HL-60/patologia , Humanos , Potenciais da Membrana/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/enzimologiaAssuntos
Biópsia/métodos , Neoplasias Pulmonares/patologia , Sarcoma de Kaposi/patologia , Adulto , Broncoscopia , Humanos , MasculinoRESUMO
Hypermethylation of CpG island is a common mechanism by which tumor suppressor genes are inactivated. The tumor suppressor genes p16(INK4a) and p15(INK4b) are important components of the cell cycles. We have studied the feasibility of detecting tumor-associated aberrant p16(INK4a) and p15(INK4b) methylation in non-small cell lung cancer (NSCLC) using methylation-specific PCR. We found a high frequency of hypermethylation of the p16(INK4a) gene in 17 of 45 cases of NSCLC. In this study, there was no difference between the clinicopathological features or overall survival of patients with and without p16(INK4a) methylation. On the other hand, p15(INK4b) promoter hypermethylation is rare (5/45) in lung cancer and occurs in association with p16(INK4a) methylation. The overall survival of patients with p15(INK4b) methylation was markedly shortened in this series. We also analyzed cells in bronchial washings, and p16(INK4a) methylation was detected in 4 of 17 cases of NSCLC. Moreover, 1 of 10 plasma samples from patients with NSCLC was positive for p16(INK4a) methylation. Our results suggest a possible prognostic role of p15(INK4b) methylation in NSCLC, and that the detection of aberrant p16(INK4a) methylation in both bronchial washings and plasma may be useful for cancer diagnosis.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/patologia , Proteínas de Transporte/genética , Proteínas de Ciclo Celular , Inibidor p16 de Quinase Dependente de Ciclina/genética , Metilação de DNA , Neoplasias Pulmonares/patologia , Proteínas Supressoras de Tumor , Adulto , Idoso , Idoso de 80 Anos ou mais , Líquido da Lavagem Broncoalveolar/citologia , Carcinoma Pulmonar de Células não Pequenas/genética , Inibidor de Quinase Dependente de Ciclina p15 , DNA de Neoplasias/sangue , DNA de Neoplasias/genética , DNA de Neoplasias/metabolismo , Feminino , Humanos , Neoplasias Pulmonares/genética , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Regiões Promotoras Genéticas/genética , Análise de SobrevidaRESUMO
A newly approved oral fluoropyrimidine, TS-1, is a dihydropyrimide dehydrogenase (DPD)-inhibiting fluoropyrimidine (DIF) drug. We describe a case of interstitial pneumonia probably caused by TS-1. A peripheral blood lymphocytes stimulating test (DLST) with TS-1 demonstrated a substantial positive reaction. So far only three cases of TS-1-induced interstitial pneumonia have been reported but the relationship between interstitial pneumonia and TS-1 was demonstrated only in this case. Considering that interstitial pneumonia has also been reported with 5-FU, it is necessary in the future to clarify which component of this drug is directly related to interstitial pneumonia.
Assuntos
Antimetabólitos Antineoplásicos/efeitos adversos , Doenças Pulmonares Intersticiais/induzido quimicamente , Ácido Oxônico/efeitos adversos , Piridinas/efeitos adversos , Tegafur/efeitos adversos , Adenocarcinoma/tratamento farmacológico , Idoso , Combinação de Medicamentos , Humanos , Masculino , Neoplasias Gástricas/tratamento farmacológicoRESUMO
BACKGROUND: The changes in the basement membrane occurring in acutely deteriorated renal allografts (ADR) have not been extensively investigated. Our purpose is to elucidate the alteration of collagen IV, a main constituent of the basement membrane in ADR. METHODS: Fifty biopsy specimens of ADR and 10 of chronic transplant nephropathy (CTN) were examined with two monoclonal antibodies specific for collagen IV. JK199 and JK132 are monoclonal antibodies that recognize triple helical collagen IV containing the alpha1 chain. JK199 recognizes all the basement membrane containing [alpha1 (IV)]2alpha2(IV), although JK132 reacts only with a limited portion of it. In the normal kidney, JK199 reacts with the mesangial matrix, the basement membrane of Bowman's capsule (BBM), and the tubular basement membrane, as well as with the glomelular basement membrane (GBM). JK132 reacts with the mesangial matrix, BBM, and the tubular basement membrane. RESULTS: In ADR, increased intensity of JK199 was observed in GBM, the mesangial matrix, BBM, the tubular basement membrane, and the interstitium. Increased intensity of JK132 was observed in the mesangial matrix, BBM, and the tubular basement membrane, but was not remarkable in GBM or the interstitium. In contrast, biopsy specimens of CTN showed increased intensity of JK132 in GBM, the mesangial matrix, BBM, the tubular basement membrane and the interstitium. CONCLUSION: These results suggest that collagen IV is up-regulated in ADR. Differential staining of collagen IV with JK199 and JK132 in GBM and the interstitium may contribute to diagnose CTN.
Assuntos
Colágeno/metabolismo , Transplante de Rim , Rim/metabolismo , Rim/patologia , Adulto , Feminino , Humanos , Imuno-Histoquímica , Nefropatias/etiologia , Nefropatias/patologia , Transplante de Rim/efeitos adversos , Masculino , Pessoa de Meia-Idade , Transplante HomólogoAssuntos
Apoptose , Caspases/metabolismo , Endopeptidases/química , Endopeptidases/metabolismo , Precursores Enzimáticos/metabolismo , Animais , Cálcio/metabolismo , Carcinoma Hepatocelular , Caspase 3 , Domínio Catalítico , Catepsinas/antagonistas & inibidores , Membrana Celular/metabolismo , Cromatografia por Troca Iônica , Citoplasma/metabolismo , Relação Dose-Resposta a Droga , Eletroforese em Gel de Poliacrilamida , Ativação Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Compostos de Epóxi/farmacologia , Galactosamina/metabolismo , Galactosamina/farmacologia , Humanos , Neoplasias Hepáticas/metabolismo , Lisossomos/metabolismo , Masculino , Camundongos , Camundongos Nus , Modelos Biológicos , Piridinas/farmacologia , Ratos , Proteínas Recombinantes/metabolismo , Fatores de Tempo , Distribuição Tecidual , Células Tumorais CultivadasRESUMO
Although triorganotins are potent inducers of apoptosis in various cell types, the critical targets of these compounds and the mechanisms by which they lead to cell death remain to be elucidated. There are two major pathways by which apoptotic cell death occurs: one is triggered by a cytokine mediator and the other is by a mitochondrion-dependent mechanism. To elucidate the mechanism of triorganotin-induced apoptosis, we studied the effect of tributyltin on mitochondrial function. We found that moderately low doses of tributyltin decrease mitochondrial membrane potential and induce cytochrome c release by a mechanism inhibited by cyclosporine A and bongkrekic acid. Tributyltin-induced cytochrome c release is also prevented by dithiols such as dithiothreitol and 2,3-dimercaptopropanol but not by monothiols such as GSH, N-acetyl-L-cysteine, L-cysteine and 2-mercaptoethanol. Further studies with phenylarsine oxide agarose revealed that tributyltin interacts with the adenine nucleotide translocator, a functional constituent of the mitochondrial permeability transition pore, which is selectively inhibited by dithiothreitol. These results suggest that, at low doses, tributyltin interacts selectively with critical thiol residues in the adenine nucleotide translocator and opens the permeability transition pore, thereby decreasing membrane potential and releasing cytochrome c from mitochondria, a series of events consistent with established mechanistic models of apoptosis.
Assuntos
Grupo dos Citocromos c/metabolismo , Mitocôndrias Hepáticas/efeitos dos fármacos , Mitocôndrias Hepáticas/metabolismo , Compostos de Trialquitina/toxicidade , Animais , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Ácido Egtázico/farmacologia , Técnicas In Vitro , Masculino , Potenciais da Membrana/efeitos dos fármacos , Translocases Mitocondriais de ADP e ATP/metabolismo , Oligomicinas/farmacologia , Ratos , Ratos Wistar , Compostos de Sulfidrila/farmacologiaRESUMO
BACKGROUND/AIMS: The purpose of this study was to determine if induction of HSP70 (heat shock protein 70), a stress protein which plays a cytoprotective role in response to various stimuli, protects hepatocytes from damage caused by partial hepatectomy and, if so, to elucidate the mechanism of such protection. METHODOLOGY: One hundred and eight male F344 rats weighing 190-220 g were randomly assigned to two groups with or without the presence of preconditioning. Fifteen-minute warm ischemia was applied to the liver of rats to induce HSP70, and 70% hepatectomy was performed 48 hours after the induction of HSP70 (ischemia group; n = 72). The rats in the nonischemia group did not undergo 15-min warm ischemia prior to 70% hepatectomy (nonischemia group; n = 36). Six rats, selected randomly from each group, were sacrificed at each measurement point to obtain blood and liver tissue samples. The levels of HSP70 in the liver, serum nitric oxide, levels of catalase and superoxide dismutase activity in the liver as antioxidative enzymes, and levels of Bcl-xL and Bax proteins and caspase-3-like activity in the liver as indices of apoptosis, were measured. RESULTS: The mean +/- SD level of HSP70 in the ischemia group (100 +/- 42 arbitrary unit (au)) was significantly higher than that of the nonischemia group (2 +/- 0.7 au) immediately before hepatectomy (P < 0.05). The ischemic preconditioning attenuated the liver damage caused by the subsequent partial hepatectomy. The levels of superoxide dismutase and catalase activity, serum nitric oxide level, and Bax protein level of the ischemia and nonischemia groups showed no significant differences after the partial hepatectomy. In contrast, the mean +/- SD level of Bcl-xL in the liver of the ischemia group (261 +/- 52 au) was significantly higher than that in the nonischemia group (114 +/- 33 au) 12 hours after the hepatectomy (P < 0.01). Furthermore, the mean +/- SD level of caspase-3-like activity in the liver of the ischemia group (18.1 +/- 4.6 au) was significantly lower than that of the nonischemia group (26.0 +/- 4.8 au) at 12 hours after the hepatectomy (P < 0.05). CONCLUSIONS: HSP70 induced by ischemic preconditioning prior to the partial hepatectomy was considered to protect the liver itself. In addition, the induced HSP70 may affect the Bcl-xL level after partial hepatectomy. Therefore, Bcl-xL seems to be involved in the reduction of liver damage after partial hepatectomy along with HSP.
Assuntos
Proteínas de Choque Térmico HSP70/fisiologia , Hepatectomia , Precondicionamento Isquêmico , Fígado/irrigação sanguínea , Alanina Transaminase/sangue , Animais , Apoptose/fisiologia , Aspartato Aminotransferases/sangue , Western Blotting , Catalase/metabolismo , Hepatócitos/fisiologia , Fígado/enzimologia , Testes de Função Hepática , Masculino , Período Pós-Operatório , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Distribuição Aleatória , Ratos , Ratos Endogâmicos F344 , Superóxido Dismutase/metabolismo , Proteína X Associada a bcl-2 , Proteína bcl-XRESUMO
The cytotoxicity of diesel exhaust particles (DEPs) toward human leukemic promyelocytic cells HL-60 was examined. DEPs were toxic and cytotoxicity increased in a dose-dependent manner. All cells died with 750 microg/ml DEPs in culture media. Apoptosis occurred in HL-60 cells exposed to DEPs. The cytotoxicity of DEP extracts with organic solvents was much lower than those of DEPs and organic solvent-washed residual DEPs. HL-NR6 cells, an HL-60 variant cell line, having higher superoxide dismutase and catalase activities than HL-60 cells, were more resistant to DEP cytotoxicity. When preincubated with the fluorescent probe diacetoxymethyl 6-carboxy-2',7'-dichlorodihydrofluorescinate diacetate and then exposed to DEPs, HL-60 cells emitted green fluorescence under blue illumination, indicating that reactive oxygen species were generated within the cells. The DEP cytotoxicity correlated inversely with the cellular concentration of reduced glutathione (GSH), which had been attenuated with L-buthionine-(R,S)-sulfoximine, a gamma-glutamylcysteine synthetase inhibitor, and was lowered with ethyl reduced glutathionate, a GSH carrier across biomembranes. Further, DEPs themselves decreased the cellular concentration of GSH in a dose-dependent manner. The alpha-tocopherol model compound 2,2,5,7,8-pentamethylchroman-6-ol decreased DEP cytotoxicity, while alpha-tocopherol had no effect. In addition, quinacrine, an endocytosis inhibitor, decreased DEP cytotoxicity. These results show that DEPs are cytotoxic and suggest that the cytotoxicity results from generation of reactive oxygen species by DEPs which have been incorporated into cells.
Assuntos
Emissões de Veículos/toxicidade , Antioxidantes/metabolismo , Butionina Sulfoximina/farmacologia , Morte Celular/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Glutationa/metabolismo , Células HL-60 , Humanos , Microscopia de Fluorescência , Quinacrina/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Vitamina E/farmacologiaRESUMO
We report a patient with diffuse malignant pleural mesothelioma showing marked elevation of neutrophils. The level of serum granulocyte-colony stimulating factor (G-CSF) was elevated (138 pg/mL; normal range, < 20 pg/mL). The patient died 6 weeks after disease progression had been noted, and immunohistochemistry using a specific monoclonal antibody against recombinant G-CSF at autopsy demonstrated that the malignant mesothelioma cells actually produced G-CSF. Only three cases of malignant pleural mesothelioma, including the current patient, have been reported to produce G-CSF. We demonstrated an elevated serum level of G-CSF and G-CSF-bearing tumor cells by immunochemistry.
Assuntos
Fator Estimulador de Colônias de Granulócitos/biossíntese , Mesotelioma/metabolismo , Neoplasias Pleurais/metabolismo , Fator Estimulador de Colônias de Granulócitos/sangue , Humanos , Técnicas Imunoenzimáticas , Masculino , Pessoa de Meia-IdadeRESUMO
The prevalence of antihepatitis virus C (HCV) antibodies in chronic hemodialysis (HD) patients is higher than in normal populations, and yet hepatocellular carcinoma (HCC) is infrequent in chronic HD patients who are HCV antibody positive. In this study, we investigated the characteristics of HCV-antibody-positive patients with HCC on chronic HD. A total of 6,366 cases of HCV-antibody-positive patients on chronic HD therapy was analyzed on the basis of answers to questionnaires on the incidence rate of HCC in 314 Japanese dialysis institutions. HCC was a complication in 114 of 6,222 (1.8%) HCV-antibody-positive patients, and cirrhosis was a complication in 536 of 6,242 (8.6%). The incidence rate of both complications was significantly higher in males than in females, and the incidence rate in the chronic HD patients was much lower than in normal populations. Specific immunological status in patients on chronic HD therapy may be an important key for preventing the progression of chronic HCV hepatitis. However, further research is needed because this study was preliminary and excluded the type of HCV virus, pathological findings, and laboratory data.