RESUMO
Helicobacter pylori (H. pylori) is one of the main causes of gastric gancer. TNF-related apoptosis-inducing ligand (TRAIL) is a protein able to promote apoptosis in cancer cells, however not in gastric cancer, which presents resistance to apoptosis via TRAIL. It is believed that MicroRNA-106b-5p might be involved in this resistance, although its role in Gastric Cancer is unclear. We aimed to determine the expression of microRNA-106b-5p and TRAIL in patients with gastric diseases, infected by H. pylori, and understand the relationship between these genes and their role in apoptosis and the gastric cancer pathways. H. pylori was detected by PCR, gene expression analysis was performed by real-time-qPCR, and bioinformatics analysis was performed using the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Cytoscape software. A total of 244 patients were divided into groups (Control, Gastritis, and Cancer); H. pylori was detected in 42.2% of the samples. The cancer group had a poor expression of TRAIL (p < 0.0001) and overexpression of microRNA-106b-5p (p=0.0005), however, our results confirmed that these genes are not directly related to each other although both are apoptosis-related regulators. Our results also indicated that H. pylori decreases microRNA-106b-5p expression and that this is a carcinogenic bacterium responsible for gastric diseases.
Assuntos
Infecções por Helicobacter/genética , MicroRNAs/genética , Neoplasias Gástricas/genética , Ligante Indutor de Apoptose Relacionado a TNF/genética , Apoptose/genética , Feminino , Gastrite/genética , Gastrite/microbiologia , Gastrite/patologia , Regulação Neoplásica da Expressão Gênica/genética , Infecções por Helicobacter/microbiologia , Infecções por Helicobacter/patologia , Helicobacter pylori/genética , Helicobacter pylori/patogenicidade , Humanos , Masculino , Pessoa de Meia-Idade , Transdução de Sinais/genética , Neoplasias Gástricas/microbiologia , Neoplasias Gástricas/patologiaRESUMO
BACKGROUND: Natural killer cells (NKC) are a major component of the innate immune response to HCV, mediating their effects through TRAIL and IFN-γ. However, their function is diminished in chronic HCV patients (HCVp). Prolactin is an immunomodulatory hormone capable of activating NKC. OBJECTIVE: The study aims to explore if hyperprolactinemia can activate NKC in HCVp. METHODS: We treated twelve chronic HCVp (confidence level =95%, power =80%) for 15 days with Levosulpiride plus Cimetidine to induce mild hyperprolactinemia. Before and after treatment, we determined TRAIL and NKG2D expression on peripheral blood NKC, along with cytokine profiles, viral loads and liver function. We also evaluated in vitro effects of prolactin and/or IL-2 on NKC TRAIL or NKG2D expression and IFN-γ levels on cultured blood mononuclear cells from 8 HCVp and 7 healthy controls. RESULTS: The treatment induced mild hyperprolactinemia and increased TRAIL expression on NKC as well as the secretion of IL-1ra, IL-2, PDGF and IFN-γ. Viral loads decreased in six HCVp. IL-2 and TRAIL together explained the viral load decrease. In vitro, prolactin plus IL-2 synergized to increase TRAIL and NKG2D expression on NKC from HCVp but not in controls. CONCLUSION: Levosulpiride/Cimetidine treatment induced mild hyperprolactinaemia that was associated with NKC activation and Th1-type cytokine profile. Also, an increase in TRAIL and IL-2 was associated with viral load decrease. This treatment could potentially be used to reactivate NKC in HCVp.
Assuntos
Hepatite C Crônica/sangue , Hepatite C Crônica/tratamento farmacológico , Interleucina-2/biossíntese , Células Matadoras Naturais/metabolismo , Prolactina/sangue , Ligante Indutor de Apoptose Relacionado a TNF/biossíntese , Células Cultivadas , Cimetidina/uso terapêutico , Cimetidina/toxicidade , Expressão Gênica , Humanos , Hiperprolactinemia/sangue , Hiperprolactinemia/induzido quimicamente , Interleucina-2/genética , Células Matadoras Naturais/efeitos dos fármacos , Masculino , Estudo de Prova de Conceito , Sulpirida/análogos & derivados , Sulpirida/uso terapêutico , Sulpirida/toxicidade , Ligante Indutor de Apoptose Relacionado a TNF/genética , Carga Viral/efeitos dos fármacos , Carga Viral/fisiologiaRESUMO
Multidrug resistance (MDR) has been associated with expression of ABC transporter genes including P-glycoprotein (Pgp, MDR1, ABCB1). However, deregulation of apoptotic pathways also renders cells resistant to chemotherapy. To discover apoptosis-related genes affected by Pgp expression, we used the HeLa MDR-off system. We found that using doxycycline to control Pgp expression has a significant advantage over tetracycline, in that doxycycline caused less endogenous gene expression modification/perturbation, and was more potent than tetracycline in suppressing Pgp expression. Cells overexpressing Pgp have lower TNFSF10 (TRAIL) expression than their parental cells. Controlled downregulation of Pgp increased endogenous TRAIL protein expression. Also, ectopic overexpression of TRAIL in Pgp-positive cells was associated with a reduction in Pgp levels. However, cells expressing a functionally defective mutant Pgp showed an increase in TRAIL expression, suggesting that Pgp function is required for TRAIL suppression. Cells in which Pgp is knocked down by upregulation of TRAIL expression are less susceptible to TRAIL ligand (sTRAIL)-induced apoptosis. Our findings reveal an inverse correlation between functional Pgp and endogenous TRAIL expression. Pgp function plays an important role in the TRAIL-mediated apoptosis pathway by regulating endogenous TRAIL expression and the TRAIL-mediated apoptosis pathway in MDR cancer cells.
Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Apoptose/genética , Resistencia a Medicamentos Antineoplásicos/genética , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/genética , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/biossíntese , Linhagem Celular Tumoral , Regulação para Baixo , Doxiciclina/farmacologia , Resistência a Múltiplos Medicamentos/genética , Células HeLa , Humanos , Interferência de RNA , RNA Interferente Pequeno , Ligante Indutor de Apoptose Relacionado a TNF/biossíntese , Tetraciclina/farmacologiaRESUMO
We investigated the roles of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and its receptor death receptor 5 (DR5) in the onset of acute leukemia and changes in their expression during chemotherapy. Bone marrow samples from 16 patients newly diagnosed with acute leukemia were collected before chemotherapy. Bone marrow samples from patients with non-hematologic malignancies served as the control group. Peripheral blood samples of patients with acute leukemia were also collected before chemotherapy and at 1 and 3 days after chemotherapy. Mononuclear cells in the bone marrow and peripheral blood were isolated and used to detect the expression of TRAIL and DR5 by flow cytometry. Compared with mononuclear cells from the control group, mononuclear cells from newly diagnosed patients with acute leukemia showed no significant difference in the expression of TRAIL (P > 0.05) but showed significantly increased expression of DR5 (P < 0.05). TRAIL and DR5 expression in peripheral blood mononuclear cells after chemotherapy was significantly increased compared to expression before chemotherapy (P < 0.05). Patients showing high expression of DR5 had a higher remission rate. One of the mechanisms underlying the treatment of leukemia with chemotherapy drugs may be the induction of TRAIL and DR5, which may promote apoptosis in leukemia cells. TRAIL-mediated apoptosis is regulated by DR5 expression.
Assuntos
Expressão Gênica , Leucemia/genética , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/genética , Ligante Indutor de Apoptose Relacionado a TNF/genética , Doença Aguda , Adolescente , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Feminino , Humanos , Leucemia/diagnóstico , Leucemia/tratamento farmacológico , Leucemia/metabolismo , Masculino , Pessoa de Meia-Idade , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Indução de Remissão , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Adulto JovemRESUMO
Follicular atresia, a key phenomenon in follicle development, eliminates most of the follicles in mammalian ovaries. To investigate the molecular mechanism of follicular atresia in porcine ovaries, we investigated the mRNA expression of three important cell death ligand-receptor systems and Fox O1 in follicles with a diameter of 3-5 mm. The phosphorylation and subcellular localization of Fox O1 during granulosa cell apoptosis was also determined. TRAIL and Fas L played an important role in follicular atresia at this stage. Fox O1 expression was upregulated during atresia, and was confined to the nucleus of granulosa cells; however, phosphorylated Fox O1 was localized to the cytoplasm. These results suggest Fox O1 involvement in the regulation of TRAIL and Fas L expression during follicular atresia in pigs.
Assuntos
Proteína Ligante Fas/genética , Atresia Folicular/genética , Fatores de Transcrição Forkhead/genética , Ovário/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/genética , Animais , Apoptose/genética , Proteína Ligante Fas/metabolismo , Feminino , Atresia Folicular/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Expressão Gênica , Células da Granulosa/metabolismo , Células da Granulosa/patologia , Imuno-Histoquímica , Ovário/patologia , Fosforilação , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Suínos , Ligante Indutor de Apoptose Relacionado a TNF/metabolismoRESUMO
Allergic asthma can vanish over time either spontaneously or induced by allergen-specific immunotherapy. In mice with established airway allergic inflammation, chronic intranasal (IN) allergen challenges decreases progressively airway allergic inflammation. Here we compared the contribution of different regulatory pathways that could be associated with this phenomenon, known as local inhalational tolerance. We found that inhalational tolerance was not associated with increased number of regulatory T cells or suppressive cytokines. Instead, it was associated with increased apoptosis of airway inflammatory leukocytes revealed by annexin-V staining and the expression of apical caspase 8 and effector caspase 3. Also, the transition from acute to chronic phase was associated with a shift in the expression of pro-allergic to pro-apoptotic molecules. The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) was found to be a key molecule in mediating resolution of allergic inflammation because anti-TRAIL treatment blocked apoptosis and increased the infiltration of T helper type 2 (Th2) cells and eosinophils. Notably, repeated IN treatment with recombinant TRAIL in established airway allergic inflammation augmented leukocyte apoptosis and decreased the frequency of interleukin-5-producing Th2 cells and eosinophils to airways. Our data indicate that TRAIL signaling is sufficient for downmodulation of allergic airway disease, suggesting a potential therapeutic use of TRAIL for asthma treatment.
Assuntos
Alérgenos/imunologia , Hipersensibilidade Respiratória/imunologia , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Animais , Anticorpos Monoclonais/imunologia , Apoptose/imunologia , Caspase 3/genética , Caspase 3/metabolismo , Caspase 8/genética , Caspase 8/metabolismo , Doença Crônica , Feminino , Regulação da Expressão Gênica/imunologia , Inflamação/tratamento farmacológico , Inflamação/imunologia , Pulmão/imunologia , Pulmão/fisiopatologia , Camundongos , Camundongos Knockout , Proteínas Recombinantes/genética , Hipersensibilidade Respiratória/tratamento farmacológico , Ligante Indutor de Apoptose Relacionado a TNF/genética , Ligante Indutor de Apoptose Relacionado a TNF/uso terapêutico , Células Th2/imunologiaRESUMO
Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is expressed in different tissues and cells, including the pancreas and lymphocytes, and it can selectively induce apoptosis in tumor cells but not in most normal cells. TRAIL plays critical roles in type 1 diabetes mellitus, and is involved in type 2 diabetes mellitus (T2DM). We recently discovered the association of nonalcoholic fatty liver disease, a risk factor for T2DM, with a single nucleotide polymorphism (SNP) in the TRAIL (TNFSF10) gene at site 1595C/T (rs1131580), indicating the possible association of T2DM with this TRAIL polymorphism. The aim of this study was to investigate the relationship of the TRAIL SNP at site 1595C/T (rs1131580) with T2DM susceptibility and the biometabolic parameters of T2DM in a Han Chinese population. The polymerase chain reaction-restriction fragment length polymorphism method was used to genotype SNP rs1131580 in 292 patients with T2DM and 266 healthy controls. We found that the frequency of the CC genotype and that of the C allele of rs1131580 were significantly higher in T2DM patients than in the control group. Additionally, the triglyceride and serum creatinine levels of T2DM patients with the CC genotype were significantly higher than those of patients with the TT genotype. Thus, the CC genotype of the TRAIL SNP at 1595C/T (rs1131580) confers increased susceptible to T2DM in a Han Chinese population from Shandong Province. These data suggest that the CC genotype at this SNP is related to diabetic severity and it might be a candidate for the prognostic assessment of T2DM.
Assuntos
Diabetes Mellitus Tipo 2/genética , Estudos de Associação Genética , Ligante Indutor de Apoptose Relacionado a TNF/genética , Diabetes Mellitus Tipo 2/patologia , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , PrognósticoRESUMO
Infected dogs are urban reservoirs of Leishmania chagasi, which is a causative agent of visceral leishmaniasis (VL). Dogs exhibit immune suppression during the course of this disease, and lymphocyte apoptosis is involved in this process. To investigate apoptosis and the expression levels of FAS-FAS-associated death domain protein (CD95 or APO-1), FASL-FAS ligand protein (CD178), and TRAIL-TNF-related apoptosis-inducing ligand (CD253) receptors in peripheral blood mononuclear cells and spleen leukocytes from 38 symptomatic dogs with moderate VL and 25 healthy dogs were evaluated by flow cytometry. The apoptosis rate of blood and splenic CD4+ and CD8+ cells was higher in infected dogs than in healthy dogs. The expression levels of FAS and FASL in blood and splenic CD4+ cells were lower in infected dogs than in healthy dogs. FAS expression in CD8+ cells was higher in infected dogs than in healthy dogs; in contrast, FASL expression was lower in infected dogs. The expression of the TRAIL receptor increased only in splenic CD8+ cells from infected dogs. The FAS and FAS-L blocking antibodies confirmed the importance of these receptors in apoptosis. Our results enhance the current understanding of the immune response in dogs infected with L. chagasi, facilitating the future development of therapeutic interventions to reduce lymphocyte depletion.
Assuntos
Apoptose/efeitos dos fármacos , Doenças do Cão/parasitologia , Proteína Ligante Fas/metabolismo , Leishmaniose/veterinária , Receptor fas/metabolismo , Animais , Linfócitos T CD4-Positivos , Linfócitos T CD8-Positivos , Doenças do Cão/imunologia , Cães , Proteína Ligante Fas/genética , Feminino , Regulação da Expressão Gênica/fisiologia , Masculino , Baço/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/genética , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Receptor fas/genéticaRESUMO
Nuclear factor of activated T cells (NFAT) was described as an activation and differentiation factor in T cells. NFAT1 protein is expressed in several cell types and has been implicated in the control of the cell cycle, death and migration. Overexpression or activation of NFAT1 has been demonstrated to induce cell death in different cell types, such as T lymphocytes, Burkitt's lymphoma, and fibroblasts. Although these findings indicate a role for NFAT1 transcription factor in control of cell death, the precise mechanisms involved in this process regulated by NFAT1 are still poorly understood. The Ras/Raf/MEK/ERK pathway is activated by many growth factors and cytokines that are important in driving proliferation and preventing apoptosis and is widely implicated in cell transformation and cancer development. We show that NFAT1 protein can cooperate with Ras/Raf/MEK/ERK, but not with the JNK, p38 or NFκB pathways in cell death induction. NFAT1 can induce a cell death pathway consistent with apoptosis, which can be shifted to programmed necrosis by caspase inhibitors. Finally, through screening genes involved in cell death regulation, although we determined that TNF-α, TRAIL and PAK7 genes were up-regulated, only TNF-α expression was responsible for cell death in this context. These data suggest that NFAT1 protein activation can shift oncogenic Ras/Raf/MEK/ERK signaling to acting as a tumor suppressor pathway. These data support a potential role for regulating NFAT1 expression in gene therapy in tumors that display an activated Ras pathway, which could lead to more specific, target-directed TNF-α expression and, thus, tumor suppression.
Assuntos
Apoptose/fisiologia , Sistema de Sinalização das MAP Quinases/fisiologia , Fatores de Transcrição NFATC/metabolismo , Proteínas Proto-Oncogênicas c-raf/genética , Fatores de Transcrição/genética , Fator de Necrose Tumoral alfa/genética , Proteínas ras/metabolismo , Animais , Caspases/genética , Caspases/metabolismo , Morte Celular/genética , Linhagem Celular , Sistema de Sinalização das MAP Quinases/genética , Camundongos , Fatores de Transcrição NFATC/genética , Células NIH 3T3 , Necrose/genética , Necrose/metabolismo , Proteínas Proto-Oncogênicas c-raf/metabolismo , Transdução de Sinais , Ligante Indutor de Apoptose Relacionado a TNF/genética , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Fatores de Transcrição/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Regulação para Cima , Quinases Ativadas por p21/genética , Quinases Ativadas por p21/metabolismo , Proteínas ras/genéticaRESUMO
Tumor necrosis factor-related apoptosis-inducing ligand-TNFSF10 (TRAIL), a member of the TNF-α family and a death receptor ligand, was shown to selectively kill tumor cells. Not surprisingly, TRAIL is downregulated in a variety of tumor cells, including BCR-ABL-positive leukemia. Although we know much about the molecular basis of TRAIL-mediated cell killing, the mechanism responsible for TRAIL inhibition in tumors remains elusive because (a) TRAIL can be regulated by retinoic acid (RA); (b) the tumor antigen preferentially expressed antigen of melanoma (PRAME) was shown to inhibit transcription of RA receptor target genes through the polycomb protein, enhancer of zeste homolog 2 (EZH2); and (c) we have found that TRAIL is inversely correlated with BCR-ABL in chronic myeloid leukemia (CML) patients. Thus, we decided to investigate the association of PRAME, EZH2 and TRAIL in BCR-ABL-positive leukemia. Here, we demonstrate that PRAME, but not EZH2, is upregulated in BCR-ABL cells and is associated with the progression of disease in CML patients. There is a positive correlation between PRAME and BCR-ABL and an inverse correlation between PRAME and TRAIL in these patients. Importantly, knocking down PRAME or EZH2 by RNA interference in a BCR-ABL-positive cell line restores TRAIL expression. Moreover, there is an enrichment of EZH2 binding on the promoter region of TRAIL in a CML cell line. This binding is lost after PRAME knockdown. Finally, knocking down PRAME or EZH2, and consequently induction of TRAIL expression, enhances Imatinib sensibility. Taken together, our data reveal a novel regulatory mechanism responsible for lowering TRAIL expression and provide the basis of alternative targets for combined therapeutic strategies for CML.