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1.
Eur J Pharmacol ; 975: 176644, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38754535

RESUMO

Metabolic dysfunction-associated fatty liver disease is a metabolic disease caused by abnormal lipid accumulation in the liver. Excessive lipid accumulation results in liver inflammation and fibrosis. Previous studies have demonstrated that the chalcone licochalcone D, which is isolated from Glycyrrhiza inflata Batal, has anti-tumor and anti-inflammatory effects. The present study explored whether licochalcone D can regulate lipid accumulation in fatty liver cells. FL83B hepatocytes were incubated with oleic acid to establish a fatty liver cell model, and then treated with licochalcone D to evaluate the molecular mechanisms underlying the regulation of lipid metabolism. In addition, male C57BL/6 mice were fed a methionine/choline-deficient diet to induce an animal model of metabolic dysfunction-associated steatohepatitis (MASH) and given 5 mg/kg licochalcone D by intraperitoneal injection. In cell experiments, licochalcone D significantly reduced lipid accumulation in fatty liver cells and reduced sterol regulatory element-binding protein 1c expression, blocking fatty acid synthase production. Licochalcone D increased adipose triglyceride lipase and carnitine palmitoyltransferase 1 expression, enhancing lipolysis and fatty acid ß-oxidation, respectively. Licochalcone D also significantly increased SIRT-1 and AMPK phosphorylation, reducing acetyl-CoA carboxylase phosphorylation and inhibiting fatty acid synthesis. Licochalcone D also increased the fusion of autophagosomes and lysosomes to promote autophagy, reducing oil droplet accumulation in fatty liver cells. In the animal experiments, licochalcone D effectively reduced the number of lipid vacuoles and degree of fibrosis in liver tissue and inhibited liver inflammation. Thus, licochalcone D can improve MASH by reducing lipid accumulation, inhibiting inflammation, and increasing autophagy.

2.
Kaohsiung J Med Sci ; 39(12): 1213-1221, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37819590

RESUMO

Mulberroside F is isolated from the leaves and roots of Morus alba L. Here, we investigated whether mulberroside F could alleviate airway inflammation and eosinophil infiltration in the lungs of asthmatic mice. We also examined whether mulberroside F attenuated inflammatory responses in human tracheal epithelial BEAS-2B cells. Female BALB/c mice were sensitized and challenged with ovalbumin (OVA), and administered different doses of mulberroside F via intraperitoneal injection. Additionally, tumor necrosis factor (TNF)-α-stimulated BEAS-2B cells were treated with various doses of mulberroside F, followed by detection of the expressions of inflammatory cytokines and chemokines. The results demonstrated that mulberroside F mitigated the levels of proinflammatory cytokines and chemokines, and CCL11, in inflammatory BEAS-2B cells. Mulberroside F also suppressed reactive oxygen species (ROS) production and ICAM-1 expression in TNF-α-stimulated BEAS-2B cells, which effectively suppressed monocyte cell adherence. In an animal model of asthma, mulberroside F treatment attenuated airway hyperresponsiveness, eosinophil infiltration, and goblet cell hyperplasia. Mulberroside F treatment also decreased lung fibrosis and airway inflammation in OVA-sensitized mice. Moreover, mulberroside F significantly reduced expressions of Th2-associated cytokines (including interleukin(IL)-4, IL-5, and IL-13) in bronchoalveolar lavage fluid compared to OVA-sensitized mice. Our results confirmed that mulberroside F is a novel bioactive compound that can effectively reduce airway inflammation and eosinophil infiltration in asthmatic mice via inhibition of Th2-cell activation.


Assuntos
Asma , Hipersensibilidade Respiratória , Feminino , Humanos , Animais , Camundongos , Ovalbumina/metabolismo , Ovalbumina/farmacologia , Ovalbumina/uso terapêutico , Asma/tratamento farmacológico , Asma/metabolismo , Pulmão/patologia , Hipersensibilidade Respiratória/metabolismo , Hipersensibilidade Respiratória/patologia , Citocinas/metabolismo , Quimiocinas/metabolismo , Inflamação/patologia , Fator de Necrose Tumoral alfa/metabolismo , Camundongos Endogâmicos BALB C , Modelos Animais de Doenças
4.
BMB Rep ; 52(9): 548-553, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31072446

RESUMO

Ets-1 is a prototype of the ETS protein family. Members of the ETS protein family contain a unique ETS domain. Ets-1 is associated with cancer progression and metastasis in many types of cancer. Many studies have shown a link between elevated expression of Ets-1 in cancer biopsies and poor survival. CCR7 is a chemokine that binds to specific ligand CCL21/CCL19. CCR7 expression is associated with tumor metastasis and infiltration into lymph nodes. The objective of this study was to test whether Ets-1 could regulate CCR7 expression and enhance tumor metastasis. Our data showed that CCR7 expression was downregulated in Ets-1-deficient T cells upon T-cell stimulation. Overexpression of Ets-1 increased CCR7 expression in breast cancer cell lines. In contrast, knockdown of Ets-1 reduced CCR7 expression. Ets-1 could directly bind to CCR7 promoter and mediate CCR7 expression in luciferase reporter assays and chromatin immunoprecipitation assays. Transactivation activity of Ets-1 was independent of the Pointed domain of Ets-1. Ets-1 could also enhance NF-κB and CBP transactivation of CCR7 promoter. Our results also showed that Ets-1 could modulate cancer cell transmigration by altering CCR7 expression in transwell assay and wound healing assay. Taken together, our data suggest that Ets-1 can enhance CCR7 expression and contribute to tumor cell migration. [BMB Reports 2019; 52(9): 548-553].


Assuntos
Regulação Neoplásica da Expressão Gênica/genética , Proteína Proto-Oncogênica c-ets-1/metabolismo , Receptores CCR7/genética , Receptores CCR7/metabolismo , Linhagem Celular Tumoral , Movimento Celular/genética , Quimiocina CCL19/genética , Quimiocina CCL19/metabolismo , Quimiocina CCL21/genética , Quimiocina CCL21/metabolismo , Feminino , Humanos , NF-kappa B/metabolismo , Proteína Proto-Oncogênica c-ets-1/genética , Transdução de Sinais/genética , Transdução de Sinais/fisiologia
5.
Phytomedicine ; 61: 152852, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31035052

RESUMO

BACKGROUND: A compound isolated from Sophora flavescens-sophoraflavanone G (SG)-showed anti-tumor and anti-inflammatory properties. We previously demonstrated that SG promoted apoptosis in human leukemia HL-60 cells. In the present study, we investigated the effects of SG on apoptosis in human breast cancer MDA-MB-231 cells, and explored the underlying molecular mechanisms. METHODS: MDA-MB-231 cells were treated with various SG concentrations, and cell viability was evaluated by MTT assay. Apoptotic signal proteins were detected by western blotting, and cell apoptosis was assessed using flow cytometry. RESULTS: Our results demonstrated that SG induced nuclear condensation, DNA fragmentation, reactive oxygen species production, and increased cell apoptosis in MDA-MB-231 cells. SG also suppressed migration and invasion, likely via blockage of the MAPK pathway. In the apoptotic signaling pathway, SG increased cleaved caspase-8, caspase-3, and caspase-9. SG treatment also decreased Bcl-2 and Bcl-xL expression, increased Bax expression, and prompted release of more cytochrome c from mitochondria to the cytoplasm in MDA-MB-231 cells. CONCLUSION: Overall, our findings suggest that SG might increase apoptosis, and decrease migration and invasion, in MDA-MB-231 cells through suppression of a MAPK-related pathway.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Flavanonas/farmacologia , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/patologia , Apoptose/fisiologia , Autofagia/efeitos dos fármacos , Caspases/metabolismo , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Citocromos c/metabolismo , Feminino , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Sophora/química , Neoplasias de Mama Triplo Negativas/metabolismo
6.
Cells ; 8(3)2019 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-30841634

RESUMO

A compound isolated from Glycyrrhizauralensis, licochalcone A (LA) exhibits anti-inflammatory and anti-tumor properties in various cell lines. LA has been found to promote autophagy and suppress specificity protein 1, inducing apoptosis in breast cancer cells. However, the regulation of breast cancer cell invasion and migration by LA is elusive. Thus, the present study investigated whether LA induces apoptosis and cellular motility in MDA-MB-231 breast cells, and investigated the underlying molecular mechanisms. MDA-MB-231 cells treated with LA and cell viability measured by cell counting kit-8 assay. Apoptotic signal proteins checked by flow cytometry, fluorescent staining, and Western blot. LA effectively suppressed cell migration, and modulated E-cadherin and vimentin expression by blocking MAPK and AKT signaling. LA inhibited cell proliferation and cell cycle, modulated mitochondrial membrane potential and DNA damage, and reduced oxidative stress in MDA-MB-231 cells. LA also activated cleaved-caspase 3 and 9, significantly decreased Bcl-2 expression, ultimately causing the release of cytochrome c from the mitochondria into the cytoplasm. Overall, our findings suggest that LA decreases cell proliferation and increases reactive oxygen species production for induced apoptosis, and regulates E-cadherin and vimentin by reducing MAPK and AKT signaling, resulting in suppressed MDA-MB-231 cell migration and invasion.


Assuntos
Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Caderinas/metabolismo , Movimento Celular/efeitos dos fármacos , Chalconas/farmacologia , Sistema de Sinalização das MAP Quinases , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Neoplasias da Mama/enzimologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Chalconas/química , Dano ao DNA , Feminino , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Modelos Biológicos , Receptores Ativados por Proliferador de Peroxissomo/metabolismo , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Cicatrização/efeitos dos fármacos
7.
Molecules ; 23(12)2018 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-30551590

RESUMO

Bulnesia sarmientoi (BS) has long been used as an analgesic, wound-healing and anti-inflammatory medicinal plant. The aqueous extract of its bark has been demonstrated to have anti-cancer activity. This study investigated the anti-proliferative and anti-metastatic effects of BS supercritical fluid extract (BSE) on the A549 and H661 lung cancer cell lines. The cytotoxicity on cancer cells was assessed by an MTT assay. After 72 h treatment of A549 and H661 cells, the IC50 values were 18.1 and 24.7 µg/mL, respectively. The cytotoxicity on MRC-5 normal cells was relatively lower (IC50 = 61.1 µg/mL). BSE arrested lung cancer cells at the S and G2/M growth phase. Necrosis of A549 and H661 cells was detected by flow cytometry with Annexin V-FITC/PI double staining. Moreover, the cytotoxic effect of BSE on cancer cells was significantly reverted by Nec-1 pretreatment, and BSE induced TNF-α and RIP-1 expression in the absence of caspase-8 activity. These evidences further support that BSE exhibited necroptotic effects on lung cancer cells. By wound healing and Boyden chamber assays, the inhibitory effects of BSE on the migration and invasion of lung cancer cells were elucidated. Furthermore, the chemical composition of BSE was examined by gas chromatography-mass analysis where ten constituents of BSE were identified. α-Guaiene, (-)-guaiol and ß-caryophyllene are responsible for most of the cytotoxic activity of BSE against these two cancer cell lines. Since BSE possesses significant cytotoxicity and anti-metastatic activity on A549 and H661 cells, it may serve as a potential target for the treatment of lung cancer.


Assuntos
Apoptose/efeitos dos fármacos , Cromatografia com Fluido Supercrítico , Neoplasias Pulmonares/patologia , Extratos Vegetais/farmacologia , Zygophyllaceae/química , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Cisplatino/farmacologia , Humanos , Necrose , Invasividade Neoplásica , Metástase Neoplásica , Extratos Vegetais/química , Cicatrização/efeitos dos fármacos
8.
Onco Targets Ther ; 9: 4453-64, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27499639

RESUMO

Lapatinib is an oral-form dual tyrosine kinase inhibitor of epidermal growth factor receptor (EGFR or ErbB/Her) superfamily members with anticancer activity. In this study, we examined the effects and mechanism of action of lapatinib on several human leukemia cells lines, including acute myeloid leukemia (AML), chronic myeloid leukemia (CML), and acute lymphoblastic leukemia (ALL) cells. We found that lapatinib inhibited the growth of human AML U937, HL-60, NB4, CML KU812, MEG-01, and ALL Jurkat T cells. Among these leukemia cell lines, lapatinib induced apoptosis in HL-60, NB4, and Jurkat cells, but induced nonapoptotic cell death in U937, K562, and MEG-01 cells. Moreover, lapatinib treatment caused autophagic cell death as shown by positive acridine orange staining, the massive formation of vacuoles as seen by electronic microscopy, and the upregulation of LC3-II, ATG5, and ATG7 in AML U937 cells. Furthermore, autophagy inhibitor 3-methyladenine and knockdown of ATG5, ATG7, and Beclin-1 using short hairpin RNA (shRNA) partially rescued lapatinib-induced cell death. In addition, the induction of phagocytosis and ROS production as well as the upregulation of surface markers CD14 and CD68 was detected in lapatinib-treated U937 cells, suggesting the induction of macrophagic differentiation in AML U937 cells by lapatinib. We also noted the synergistic effects of the use of lapatinib and cytotoxic drugs in U937 leukemia cells. These results indicate that lapatinib may have potential for development as a novel antileukemia agent.

9.
Molecules ; 21(8)2016 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-27527140

RESUMO

Type II endometrial carcinoma typically exhibits aggressive metastasis and results in a poor prognosis. Siegesbeckia orientalis Linne is a traditional Chinese medicinal herb with several medicinal benefits, including the cytotoxicity against various cancers. This study investigates the inhibitory effects of S. orientalis ethanol extract (SOE) on the migration and invasion of endometrial cancer cells, which were stimulated by transforming growth factor ß (TGFß). The inhibitory effects were evaluated by determining wound healing and performing the Boyden chamber assay. This study reveals that SOE can inhibit TGFß1-induced cell wound healing, cell migration, and cell invasion in a dose-dependent manner in RL95-2 and HEC-1A endometrial cancer cells. SOE also reversed the TGFß1-induced epithelial-mesenchymal transition, including the loss of the cell-cell junction and the lamellipodia-like structures. Western blot analysis revealed that SOE inhibited the phosphorylation of ERK1/2, JNK1/2, and Akt, as well as the expression of MMP-9, MMP-2, and u-PA in RL95-2 cells dose-dependently. The results of this investigation suggest that SOE is a potential anti-metastatic agent against human endometrial tumors.


Assuntos
Asteraceae/química , Neoplasias do Endométrio/metabolismo , Etanol/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Fator de Crescimento Transformador beta1/efeitos adversos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Neoplasias do Endométrio/tratamento farmacológico , Neoplasias do Endométrio/patologia , Etanol/química , Feminino , Humanos , Invasividade Neoplásica , Extratos Vegetais/química , Extratos Vegetais/farmacologia
10.
BMC Complement Altern Med ; 15: 237, 2015 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-26179175

RESUMO

BACKGROUND: Antrodia camphorata is a geographically special fungus and is one of the precious traditional medicines of Taiwan. A lot of reports have addressed its antioxidant activities and anticancer activities. In order to understand whether these protection effects were resulted from its ability of preventing DNA against hydroxyl radical damage, the A. camphorata extract was used to examine its antioxidant, antimutagenic and DNA-protective activities. METHODS: A. camphorata extract was prepared by extracting the lyophilized powder of A. camphorata mycelium with distilled water. The antioxidative activity of this A. camphorata extract was then evaluated by 2,2-diphenyl-1-picrylhydrozyl (DPPH) radical-scavenging assay, and the antimutagenic activities of the extract against direct mutagen 4-nitroquinoline N-oxide (4NQNO) and indirect mutagen benzo[a]pyrene (B[a]P) were evaluated by Ames test. The effects of the A. camphorata extract in terms of DNA protection against hydroxyl radical damage were also investigated. RESULTS: It was found that the higher the concentration of A. camphorata extracts, the higher the DPPH radical-scavenging effect. A. camphorata extract at concentrations between 0.625 and 10 mg/ml was found to be neither toxic nor mutagenic. However, the higher A. camphorata concentration (10 mg/ml) used in the test showed higher inhibitory effects on 4NQNO in a dose-dependent manner. The A. camphorata extract also showed reducing and scavenging activities against superoxide anion radical and also exhibited protective effects on DNA against hydroxyl radical-induced damage. CONCLUSIONS: Results suggested that A. camphorata is a non-toxic and novel material with antioxidant, antimutagenic and DNA-protective activities and could be developed into health foods.


Assuntos
Antioxidantes/farmacologia , Antrodia , Produtos Biológicos/farmacologia , DNA/efeitos dos fármacos , Radical Hidroxila/metabolismo , Mutagênese/efeitos dos fármacos , Medicina Tradicional Chinesa , Mutagênicos , Micélio/efeitos dos fármacos , Oxirredução , Taiwan
11.
Inflamm Res ; 64(8): 577-88, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26059394

RESUMO

OBJECTIVES AND DESIGN: Sesamol is a lignan isolated from sesame seed oil. In recent years, it was found that sesamol could decrease lung inflammation and lipopolysaccharide (LPS)-induced lung injury in rats. In this study, we investigated whether sesamol exhibited anti-inflammatory activity in LPS-stimulated macrophages. MATERIALS AND METHODS: RAW 264.7 cells were treated with sesamol, then treated with LPS to induce inflammation. The levels of proinflammatory cytokines were analyzed with ELISA. The gene and protein expression of cyclooxygenase (COX)-2, inducible nitric oxide synthase (iNOS), and nuclear factor erythroid-2-related factor 2 (Nrf2) were evaluated with real-time PCR and Western blots, respectively. We also examined inflammatory signaling pathways, including nuclear transcription factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways. RESULTS: Sesamol inhibited production of nitric oxide, prostaglandin E2 (PGE2), and proinflammatory cytokines. Sesamol markedly suppressed mRNA and protein expression of iNOS and COX-2. Sesamol enhanced the protective antioxidant pathway represented by Nrf2 and HO-1. Moreover, sesamol suppressed NF-κB transport into the nucleus and decreased MAPK activation, but it promoted adenosine monophosphate-activated protein kinase (AMPK) activation. CONCLUSIONS: These data suggested that sesamol ameliorated inflammatory and oxidative damage by upregulating AMPK activation and Nrf2 signaling and blocking the NF-κB and MAPK signaling pathways.


Assuntos
Anti-Inflamatórios/farmacologia , Benzodioxóis/farmacologia , Macrófagos/efeitos dos fármacos , Fenóis/farmacologia , Adenilato Quinase/metabolismo , Animais , Linhagem Celular , Ciclo-Oxigenase 2/genética , Ciclo-Oxigenase 2/metabolismo , Citocinas/metabolismo , Dinoprostona/metabolismo , Heme Oxigenase-1/metabolismo , Macrófagos/metabolismo , Proteínas de Membrana/metabolismo , Camundongos , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fator 2 Relacionado a NF-E2/genética , NF-kappa B/antagonistas & inibidores , NF-kappa B/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Regulação para Cima
12.
J Immunol ; 190(10): 5065-77, 2013 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-23589610

RESUMO

Mesenchymal stem/stromal cells (MSCs) are promising potential candidates for the treatment of immunological diseases because of their immunosuppressive functions. However, the molecular mechanisms that mediate MSCs' immunosuppressive activity remain elusive. In this article, we report for the first time, to our knowledge, that secreted growth-regulated oncogene (GRO) chemokines, specifically GRO-γ, in human MSC-conditioned media have an effect on the differentiation and the function of human monocyte-derived dendritic cells. The monocyte-derived dendritic cells were driven toward a myeloid-derived suppressor cell (MDSC)-like phenotype by the GRO chemokines. GRO-γ-treated MDSCs had a tolerogenic phenotype that was characterized by an increase in the secretion of IL-10 and IL-4, and a reduction in the production of IL-12 and IFN-γ. We have also shown that the mRNA expression levels of the arginase-1 and inducible NO synthase genes, which characterize MDSCs, were upregulated by GRO-γ-primed mouse bone marrow cells. In addition, the ability of GRO-γ-treated bone marrow-derived dendritic cells to stimulate the OVA-specific CD8(+) T (OT-1) cell proliferation and the cytokine production of IFN-γ and TNF-α were significantly decreased in vivo. Our findings allow a greater understanding of how MDSCs can be generated and offer new perspectives to exploit the potential of MDSCs for alternative approaches to treat chronic inflammation and autoimmunity, as well as for the prevention of transplant rejection.


Assuntos
Linfócitos T CD8-Positivos/metabolismo , Quimiocinas CXC/metabolismo , Células Dendríticas/metabolismo , Células-Tronco Mesenquimais/metabolismo , Células Mieloides/citologia , Animais , Arginase/biossíntese , Arginase/genética , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/metabolismo , Diferenciação Celular/imunologia , Proliferação de Células , Células Cultivadas , Quimiocina CXCL1/farmacologia , Quimiocina CXCL2/farmacologia , Quimiocinas CXC/fisiologia , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Humanos , Interferon gama/biossíntese , Interferon gama/metabolismo , Interleucina-10/metabolismo , Interleucina-12/metabolismo , Interleucina-4/metabolismo , Receptores de Lipopolissacarídeos/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Monócitos/metabolismo , Células Mieloides/imunologia , Óxido Nítrico Sintase Tipo II/biossíntese , Óxido Nítrico Sintase Tipo II/genética , Fenótipo , RNA Mensageiro/biossíntese , Fator de Necrose Tumoral alfa/biossíntese
13.
J Immunol ; 180(5): 3238-49, 2008 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-18292548

RESUMO

Death-associated protein kinase (DAPK) is a unique multidomain kinase acting both as a tumor suppressor and an apoptosis inducer. The molecular mechanism underlying the effector function of DAPK is not fully understood, while the role of DAPK in T lymphocyte activation is mostly unknown. DAPK was activated after TCR stimulation. Through the expression of a dominant-negative and a constitutively active form of DAPK in T cells, we found that DAPK negatively regulated T cell activation. DAPK markedly affected T cell proliferation and IL-2 production. We identified TCR-induced NF-kappaB activation as a target of DAPK. In contrast, IL-1beta- and TNF-alpha-triggered NF-kappaB activation was not affected by DAPK. We further found that DAPK selectively modulated the TCR-induced translocation of protein kinase Ctheta, Bcl-10, and IkappaB kinase into membrane rafts. Notably, the effect of DAPK on the raft entry was specific for the NF-kappaB pathway, as other raft-associated molecules, such as linker for activation of T cells, were not affected. Our results clearly demonstrate that DAPK is a novel regulator targeted to TCR-activated NF-kappaB and T cell activation.


Assuntos
Proteínas Reguladoras de Apoptose/fisiologia , Proteínas Quinases Dependentes de Cálcio-Calmodulina/fisiologia , Regulação para Baixo/imunologia , Marcação de Genes , NF-kappa B/metabolismo , Receptores de Antígenos de Linfócitos T/fisiologia , Linfócitos T/enzimologia , Proteínas Supressoras de Tumor/fisiologia , Animais , Proteínas Reguladoras de Apoptose/antagonistas & inibidores , Proteínas Reguladoras de Apoptose/genética , Proteínas Quinases Dependentes de Cálcio-Calmodulina/antagonistas & inibidores , Proteínas Quinases Dependentes de Cálcio-Calmodulina/genética , Células Cultivadas , Proteínas Quinases Associadas com Morte Celular , Regulação para Baixo/genética , Humanos , Células Jurkat , Ativação Linfocitária/genética , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , NF-kappa B/genética , NF-kappa B/fisiologia , Fosforilação , RNA Interferente Pequeno/genética , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Proteínas Supressoras de Tumor/antagonistas & inibidores , Proteínas Supressoras de Tumor/genética
14.
J Biol Chem ; 279(1): 13-8, 2004 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-14578361

RESUMO

Cellular FLICE (FADD-like interleukin-1-beta-converting enzyme)-inhibitory protein (c-FLIP) inhibits death receptor-induced apoptosis by binding to FADD (Fas-associated death domain protein) and pro-caspase-8. c-FLIP has also been shown to transmit activation signals and to enhance interleukin (IL)-2 production. However, c-FLIP-mediated T cell activation is difficult to detect in most cells. We found that in DO11.10 T cells, c-FLIP expression led to inhibition of IL-2 production, in contrast to the readily detectable c-FLIP-induced activation in Jurkat cells. A direct comparison revealed that distinct signal pathways were regulated by c-FLIP in Jurkat cells and DO11.10 cells. We investigated whether constitutively activated phosphatidylinositide 3-kinase (PI3K) in Jurkat cells stimulated c-FLIP. Inhibition of PI3K in Jurkat cells abrogated a c-FLIP-mediated increase in IL-2 production. In addition, c-FLIP coordinated with active PI3K for ERK activation. Furthermore, introduction of PTEN back into Jurkat cells eliminated the stimulatory effect of c-FLIP on IL-2 production and ERK activation. Our results suggest that priming with PI3K promotes the coupling of c-FLIP to T cell activation.


Assuntos
Proteínas de Transporte/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular , Ativação Linfocitária/imunologia , Fosfatidilinositol 3-Quinases/metabolismo , Linfócitos T/imunologia , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD , Proteínas de Transporte/genética , Proteínas de Transporte/imunologia , Linhagem Celular , Ativação Enzimática , Humanos , Interleucina-2/antagonistas & inibidores , Interleucina-2/biossíntese , Células Jurkat , Sistema de Sinalização das MAP Quinases/fisiologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , PTEN Fosfo-Hidrolase , Monoéster Fosfórico Hidrolases/genética , Monoéster Fosfórico Hidrolases/metabolismo , Proteínas Recombinantes/metabolismo , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo
15.
Oncogene ; 22(50): 8168-77, 2003 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-14603257

RESUMO

DNA-damaging reagents may kill tumor cells through the generation of reactive oxygen species (ROS). Cytotoxic reagents may also induce apoptosis of cancer cells in Fas-FADD-dependent manners. In this study, we explored the possible link between these two apparently distinct pathways in T leukemia cell Jurkat. Our results demonstrated that gamma-irradiation, similar to cisplatin, induced apoptosis by triggering Fas aggregation and activating FADD-caspase-8 apoptotic cascade. The absence of caspase-8 or Fas greatly reduced the sensitivity to apoptosis mediated by DNA-damaging agents. In addition, apoptosis induced by cisplatin and gamma-irradiation, but not by Fas, was inhibited by ROS scavengers, including N-acetyl cysteine, MnTBAP, and C60. Importantly, these ROS scavengers effectively prevented the clustering of Fas receptor induced by cisplatin and gamma-irradiation. Our results suggest that cisplatin and gamma-irradiation promote ROS production, which in turn contributes to Fas receptor aggregation and cell death. The novel coupling between ROS and Fas clustering likely plays a significant role in apoptosis triggered by DNA-damaging reagents in Fas-expressing leukemia cells.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Apoptose/efeitos da radiação , Dano ao DNA/efeitos da radiação , Espécies Reativas de Oxigênio/metabolismo , Receptor fas/efeitos da radiação , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Proteínas de Transporte/metabolismo , Caspase 8 , Caspase 9 , Caspases/metabolismo , Cisplatino/farmacologia , Proteína Ligante Fas , Proteína de Domínio de Morte Associada a Fas , Raios gama , Humanos , Células Jurkat , Glicoproteínas de Membrana/metabolismo
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