Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Pharmaceutics ; 13(4)2021 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-33807390

RESUMO

Patients need medications at a dosage suited to their physiological characteristics. Three-dimensional printing (3DP) technology by fused-filament fabrication (FFF) is a solution for manufacturing medication on demand. The aim of this work was to identify important parameters for the production of reproducible filament batches used by 3DP for oral formulations. Amiodarone hydrochloride, an antiarrhythmic and insoluble drug, was chosen as a model drug because of dosage adaptation need in children. Polyethylene oxide (PEO) filaments containing amiodarone hydrochloride were produced by hot-melt extrusion (HME). Different formulation storage conditions were investigated. For all formulations, the physical form of the drug following HME and fused-deposition modeling (FDM) 3D-printing processes were assessed using thermal analysis and X-ray powder diffraction (XRPD). Filament mechanical properties, linear mass density and surface roughness, were investigated by, respectively, 3-point bending, weighing, and scanning electron microscopy (SEM). Analysis results showed that the formulation storage condition before HME-modified filament linear mass density and, therefore, the oral forms masses from a batch to another. To obtain constant filament apparent density, it has been shown that a constant and reproducible drying condition is required to produce oral forms with constant mass.

2.
Inflamm Res ; 66(11): 981-992, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28676918

RESUMO

OBJECTIVE AND DESIGN: The aim of this study was to determine potential effects of gold (+) and gold (-) nanoparticles, AuNP(+) and AuNP(-), on neutrophil biology. MATERIAL OR SUBJECTS: Freshly isolated human neutrophils were used for the in vitro aspects and CD-1 mice were used in the in vivo murine air pouch model of acute neutrophilic inflammation. TREATMENT: Human neutrophils were treated with the indicated concentrations of AuNP(+) or AuNP(-) in vitro and mice received 100 or 500 µg/ml AuNP(+) or AuNP(-) into air pouches. METHODS: Cellular uptake of AuNP by neutrophils was confirmed by transmission electron microscopy and the ability of the NP to modulate apoptosis, gelatinase activity, and chemokine production and chemotaxis was determined by cytology, zymography, ELISArray, antibody array, and ELISA and by a micro-chemotaxis chamber, respectively. In vivo, exudates were harvested after 6 h to determine the leukocyte infiltration to detect the production of several cytokines by an antibody array approach and ELISA. One-way analysis of variance was used for statistical analysis. RESULTS: AuNP possess proinflammatory activities in vitro and induce mainly a neutrophil influx in vivo, albeit at different degrees. CONCLUSIONS: AuNP(+) and AuNP(-) should be added as new candidates into a growing list of NP having proinflammatory activities by themselves.


Assuntos
Ouro/toxicidade , Nanopartículas Metálicas/toxicidade , Neutrófilos/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Sobrevivência Celular , Células Cultivadas , Quimiotaxia , Citocinas/imunologia , Feminino , Gelatinases/metabolismo , Humanos , Lipopolissacarídeos , Camundongos , Microscopia Eletrônica de Transmissão , Neutrófilos/imunologia , Neutrófilos/fisiologia , Neutrófilos/ultraestrutura
3.
J Immunotoxicol ; 13(6): 817-826, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27404512

RESUMO

Eosinophilic inflammation is frequently observed in response to nanoparticle (NP) exposure in airway rodent models of allergies where the number of eosinophils is increased in lungs. Despite this, it is surprising that the potential cytotoxic effect of NP, as well as their direct role on eosinophils is poorly documented. The present study investigated how different NP can alter the biology of the human eosinophilic cell line AML14.3D10. It was found that among NP forms of CeO2, ZnO, TiO2, and nanosilver of 20 nm (AgNP20) or 70 nm (AgNP70) diameters, only ZnO and AgNP20 induced apoptosis. Caspases-7 and -9 were not activated by the tested NP while caspase-3 was activated by AgNP20 only. However, both ZnO and AgNP20 induced cytoskeletal breakdown as evidenced by the cleavage of lamin B1. Using an ELISArray approach for the simultaneous detection of several analytes (cytokines/chemokines), it was found that only ZnO and AgNP20 increased the production of different analytes including the potent pro-inflammatory CXCL8 (IL-8) chemokine. From the data here, we conclude that toxic effects of some NP could be observed in human eosinophil-like cells and that this could be related, at least partially, by induction of apoptosis and production of cytokines and chemokines involved in inflammation. The results of this study also indicate that distinct NP do not activate similarly human eosinophils, since ZnO and AgNP20 induce apoptosis and cytokine production while others such as TiO2, CeO2, and AgNP70 do not.


Assuntos
Apoptose , Eosinófilos/imunologia , Nanopartículas Metálicas , Animais , Caspase 3/metabolismo , Linhagem Celular , Citoesqueleto/metabolismo , Humanos , Imunomodulação , Lamina Tipo B/metabolismo , Camundongos , Proteólise , Ratos , Prata , Zinco
4.
Sci Signal ; 9(421): ra32, 2016 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-27025876

RESUMO

HSN2is a nervous system predominant exon of the gene encoding the kinase WNK1 and is mutated in an autosomal recessive, inherited form of congenital pain insensitivity. The HSN2-containing splice variant is referred to as WNK1/HSN2. We created a knockout mouse specifically lacking theHsn2exon ofWnk1 Although these mice had normal spinal neuron and peripheral sensory neuron morphology and distribution, the mice were less susceptible to hypersensitivity to cold and mechanical stimuli after peripheral nerve injury. In contrast, thermal and mechanical nociceptive responses were similar to control mice in an inflammation-induced pain model. In the nerve injury model of neuropathic pain, WNK1/HSN2 contributed to a maladaptive decrease in the activity of the K(+)-Cl(-)cotransporter KCC2 by increasing its inhibitory phosphorylation at Thr(906)and Thr(1007), resulting in an associated loss of GABA (γ-aminobutyric acid)-mediated inhibition of spinal pain-transmitting nerves. Electrophysiological analysis showed that WNK1/HSN2 shifted the concentration of Cl(-)such that GABA signaling resulted in a less hyperpolarized state (increased neuronal activity) rather than a more hyperpolarized state (decreased neuronal activity) in mouse spinal nerves. Pharmacologically antagonizing WNK activity reduced cold allodynia and mechanical hyperalgesia, decreased KCC2 Thr(906)and Thr(1007)phosphorylation, and restored GABA-mediated inhibition (hyperpolarization) of injured spinal cord lamina II neurons. These data provide mechanistic insight into, and a compelling therapeutic target for treating, neuropathic pain after nerve injury.


Assuntos
Hiperalgesia/metabolismo , Neuralgia/metabolismo , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Nervos Espinhais/metabolismo , Transmissão Sináptica , Ácido gama-Aminobutírico/metabolismo , Animais , Modelos Animais de Doenças , Éxons , Hiperalgesia/genética , Hiperalgesia/fisiopatologia , Hiperalgesia/prevenção & controle , Camundongos , Camundongos Transgênicos , Antígenos de Histocompatibilidade Menor/genética , Antígenos de Histocompatibilidade Menor/metabolismo , Neuralgia/genética , Neuralgia/fisiopatologia , Neuralgia/prevenção & controle , Traumatismos dos Nervos Periféricos/genética , Traumatismos dos Nervos Periféricos/metabolismo , Traumatismos dos Nervos Periféricos/fisiopatologia , Traumatismos dos Nervos Periféricos/prevenção & controle , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Nervos Espinhais/patologia , Simportadores/genética , Simportadores/metabolismo , Proteína Quinase 1 Deficiente de Lisina WNK , Ácido gama-Aminobutírico/genética , Cotransportadores de K e Cl-
5.
J Biol Chem ; 290(9): 5926-39, 2015 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-25593314

RESUMO

In the past decade, the increasing amount of nanoparticles (NP) and nanomaterials used in multiple applications led the scientific community to investigate the potential toxicity of NP. Many studies highlighted the cytotoxic effects of various NP, including titanium dioxide, zinc oxide, and silver nanoparticles (AgNP). In a few studies, endoplasmic reticulum (ER) stress was found to be associated with NP cytotoxicity leading to apoptosis in different cell types. In this study, we report for the first time that silver nanoparticles of 15 nm (AgNP15), depending on the concentration, induced different signature ER stress markers in human THP-1 monocytes leading to a rapid ER stress response with degradation of the ATF-6 sensor. Also, AgNP15 induced pyroptosis and activation of the NLRP-3 inflammasome as demonstrated by the processing and increased activity of caspase-1 and secretion of IL-1ß and ASC (apoptosis-associated speck-like protein containing a CARD domain) pyroptosome formation. Transfection of THP-1 cells with siRNA targeting NLRP-3 decreased the AgNP15-induced IL-1ß production. The absence of caspase-4 expression resulted in a significant reduction of pro-IL-1ß. However, caspase-1 activity was significantly higher in caspase-4-deficient cells when compared with WT cells. Inhibition of AgNP15-induced ATF-6 degradation with Site-2 protease inhibitors completely blocked the effect of AgNP15 on pyroptosis and secretion of IL-1ß, indicating that ATF-6 is crucial for the induction of this type of cell death. We conclude that AgNP15 induce degradation of the ER stress sensor ATF-6, leading to activation of the NLRP-3 inflammasome regulated by caspase-4 in human monocytes.


Assuntos
Fator 6 Ativador da Transcrição/metabolismo , Proteínas de Transporte/metabolismo , Inflamassomos/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Prata/química , Apoptose/efeitos dos fármacos , Western Blotting , Proteínas de Transporte/genética , Caspase 1/metabolismo , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Células Cultivadas , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Humanos , Inflamassomos/metabolismo , Interleucina-1beta/metabolismo , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Microscopia Confocal , Microscopia Eletrônica de Transmissão , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR , Proteólise/efeitos dos fármacos , Interferência de RNA
6.
Am J Hum Genet ; 89(2): 219-30, 2011 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-21820098

RESUMO

Hereditary sensory and autonomic neuropathy type II (HSANII) is a rare autosomal-recessive disorder characterized by peripheral nerve degeneration resulting in a severe distal sensory loss. Although mutations in FAM134B and the HSN2 exon of WNK1 were associated with HSANII, the etiology of a substantial number of cases remains unexplained. In addition, the functions of WNK1/HSN2 and FAM134B and their role in the peripheral nervous system remain poorly understood. Using a yeast two-hybrid screen, we found that KIF1A, an axonal transporter of synaptic vesicles, interacts with the domain encoded by the HSN2 exon. In parallel to this screen, we performed genome-wide homozygosity mapping in a consanguineous Afghan family affected by HSANII and identified a unique region of homozygosity located on chromosome 2q37.3 and spanning the KIF1A gene locus. Sequencing of KIF1A in this family revealed a truncating mutation segregating with the disease phenotype. Subsequent sequencing of KIF1A in a series of 112 unrelated patients with features belonging to the clinical spectrum of ulcero-mutilating sensory neuropathies revealed truncating mutations in three additional families, thus indicating that mutations in KIF1A are a rare cause of HSANII. Similarly to WNK1 mutations, pathogenic mutations in KIF1A were almost exclusively restricted to an alternatively spliced exon. This study provides additional insights into the molecular pathogenesis of HSANII and highlights the potential biological relevance of alternative splicing in the peripheral sensory nervous system.


Assuntos
Axônios/metabolismo , Neuropatias Hereditárias Sensoriais e Autônomas/genética , Cinesinas/genética , Mutação/genética , Vesículas Sinápticas/metabolismo , Afeganistão , Processamento Alternativo/genética , Transporte Biológico , Células Cultivadas , Éxons/genética , Família , Feminino , Técnicas de Silenciamento de Genes , Testes Genéticos , Genoma Humano/genética , Haplótipos/genética , Homozigoto , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Cinesinas/metabolismo , Masculino , Antígenos de Histocompatibilidade Menor , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Neurônios/metabolismo , Linhagem , Ligação Proteica , Proteínas Serina-Treonina Quinases/genética , Estrutura Terciária de Proteína , RNA Interferente Pequeno/metabolismo , Proteína Quinase 1 Deficiente de Lisina WNK
7.
Br J Haematol ; 138(4): 545-54, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17659056

RESUMO

The role of the anti-cancer agent Viscum album agglutinin-I (VAA-I) in leukaemia PLB-985 cells differentiated toward a neutrophil-like phenotype by dimethylsulphoxide (PLB-985D) has never been studied. This study investigated whether or not VAA-I can induce cytoskeletal breakdown in PLB-985D cells, as previously observed in undifferentiated PLB-985 cells. VAA-I was found to induce apoptosis in PLB-985D cells, as assessed by cytology and by degradation of gelsolin, an event known to occur via caspase-3 activation. VAA-I induced cytoskeletal breakdown based on the disruption of the F-actin network and cleavage of paxillin, vimentin and lamin B(1). In addition, we demonstrated, for the first time, that non-muscle myosin heavy chain IIA (NMHC-IIA) was cleaved by VAA-I treatment. Degradation of NMHC-IIA was reversed by the pan caspase inhibitor z-VAD-fmk in PLB-985D cells and neutrophils. However, unlike lamin B(1), no NMHC-IIA was detected on the cell surface of apoptotic neutrophils. In conclusion, PLB-985D cells responded in a similar manner to neutrophils regarding the degradation of the tested cytoskeletal. Therefore, PLB-985D cells may provide a suitable substitute for neutrophils in screening experiments, preventing extensive neutrophil cell isolation.


Assuntos
Antineoplásicos/uso terapêutico , Caspases/metabolismo , Leucemia/tratamento farmacológico , Neutrófilos/imunologia , Miosina não Muscular Tipo IIA/metabolismo , Preparações de Plantas/uso terapêutico , Proteínas de Plantas/uso terapêutico , Toxinas Biológicas/uso terapêutico , Apoptose/efeitos dos fármacos , Caspases/genética , Diferenciação Celular , Linhagem Celular Tumoral , Citoesqueleto/efeitos dos fármacos , Citoesqueleto/metabolismo , Citometria de Fluxo , Humanos , Lamina Tipo B/análise , Lamina Tipo B/metabolismo , Leucemia/metabolismo , Miosina não Muscular Tipo IIA/análise , Paxilina/análise , Paxilina/metabolismo , RNA Mensageiro/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteínas Inativadoras de Ribossomos , Proteínas Inativadoras de Ribossomos Tipo 2 , Vimentina/análise , Vimentina/metabolismo
8.
Leuk Res ; 29(12): 1443-53, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16242777

RESUMO

Viscum album agglutinin-I (VAA-I) is a potent inducer of cell apoptosis and possesses anti-tumoral activity. Using PLB-985 and chronic granulomatous disease (X-CGD) cells, which lack expression of gp91(phox), VAA-I was found to induce apoptosis in both cell lines as assessed by cytology, DNA laddering and degradation of the cytoskeletal protein gelsolin. Both cell lines expressed caspase-3 and -8 and VAA-I activated these caspases. We demonstrated that lamin B(1) is a novel target to VAA-I and its degradation was reversed by a pan-caspase inhibitor and by a caspase-6, but not a caspase-8, inhibitor.


Assuntos
Apoptose/efeitos dos fármacos , Proteínas do Citoesqueleto/efeitos dos fármacos , Leucemia/patologia , Lectinas de Plantas/farmacologia , Preparações de Plantas/farmacologia , Proteínas de Plantas/farmacologia , Toxinas Biológicas/farmacologia , Caspase 3 , Caspase 8 , Caspases/efeitos dos fármacos , Caspases/metabolismo , Linhagem Celular Tumoral , Proteínas do Citoesqueleto/metabolismo , Gelsolina/antagonistas & inibidores , Humanos , Lamina Tipo B/antagonistas & inibidores , Leucemia/tratamento farmacológico , Proteínas Inativadoras de Ribossomos , Proteínas Inativadoras de Ribossomos Tipo 2 , Viscum album/química
9.
Br J Haematol ; 130(4): 527-35, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16098066

RESUMO

Although there are several agents that induce neutrophil apoptosis, few are known as inducers of eosinophil apoptosis. As eosinophils are potent effector cells contributing to allergic inflammation and asthma, we investigated whether the pro-apoptotic agent Viscum album agglutinin-I (VAA-I) could induce eosinophil apoptosis. VAA-I was found to induce apoptosis in eosinophilic AML14.3D10 (3D10) cells and that these cells expressed caspases-1, -2, -3, -4, -7, -8, -9 and -10. VAA-I-induced gelsolin degradation was reversed by the pan-caspase inhibitor N-benzyloxycarbonyl-V-A-D-O-methylfluoromethyl ketone (z-VAD). Also, paxillin, vimentin and lamin B1 were cleaved by caspases in VAA-I-induced 3D10 cells. VAA-I activated caspase-3 and -8 in 3D10 cells but, unlike z-VAD, treatment with a caspase-8 inhibitor slightly reversed apoptosis. Treatment of purified human eosinophils with VAA-I was found to induce apoptosis, degradation of gelsolin and lamin B1, but unlike 3D10 cells, cleavage of lamin B1 and cell apoptosis was not reversed by z-VAD. We conclude that VAA-I is a potent inducer of eosinophil apoptosis and that proteases other than those inhibited by z-VAD in 3D10 cells are involved in VAA-I-induced peripheral blood eosinophil apoptosis and lamin B1 cleavage. Thus, VAA-I represents a potential candidate for the reduction of the number of eosinophils in diseases where they play important roles.


Assuntos
Caspases/metabolismo , Proteínas do Citoesqueleto/metabolismo , Leucemia Mieloide/metabolismo , Preparações de Plantas/farmacologia , Proteínas de Plantas/farmacologia , Toxinas Biológicas/farmacologia , Doença Aguda , Apoptose , Caspase 3 , Caspase 8 , Caspases/análise , Linhagem Celular Tumoral , Proteínas do Citoesqueleto/análise , Proteínas do Citoesqueleto/efeitos dos fármacos , Fragmentação do DNA , Eosinófilos/metabolismo , Gelsolina/análise , Gelsolina/metabolismo , Humanos , Laminina/metabolismo , Paxilina , Fosfoproteínas/análise , Fosfoproteínas/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteínas Inativadoras de Ribossomos , Proteínas Inativadoras de Ribossomos Tipo 2 , Vimentina/análise , Vimentina/metabolismo
10.
Toxicol Sci ; 69(1): 210-6, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12215676

RESUMO

Air pollutant exposure may induce deterioration of respiratory health. Concentrations of air particles, ozone, nitrogen dioxide, sulfur dioxide, and sulfate are among the players involved in the initiation and/or exacerbation of lung diseases. We have previously documented that the pollutant sodium sulfite (Na(2)SO(3)) is a human neutrophil agonist. To date, there is no evidence in the literature that Na(2)SO(3) can activate epithelial lung cells. In the present study, we found that Na(2)SO(3) (0.01-10 mM) induces tyrosine phosphorylation events and interleukin-8 production in human epithelial lung A549 cells. In addition, we found that Na(2)SO(3) did not promote A549 cell apoptosis as assessed by the degradation of the cytoskeletal gelsolin protein and by FITC-annexin-V binding. Human neutrophil adhesion to Na(2)SO(3)-induced A549 cells was increased when compared with untreated A549 cells. As assessed by flow cytometry, cell surface expression of intercellular adhesion molecule (ICAM)-1, ICAM-3, and vascular cell adhesion molecule-1 (VCAM-1) on A549 cells was not affected by Na(2)SO(3). We conclude that Na(2)SO(3) can activate A549 cells. In addition, we conclude that neutrophil adhesion to Na(2)SO(3)-induced A549 cells is increased via an ICAM-1-, ICAM-3-, and VCAM-1-independent mechanism.


Assuntos
Poluentes Atmosféricos/toxicidade , Adesão Celular/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Neutrófilos/efeitos dos fármacos , Sulfitos/toxicidade , Antígenos de Superfície/biossíntese , Antígenos de Superfície/genética , Apoptose/efeitos dos fármacos , Linhagem Celular , Separação Celular , Células Cultivadas , Humanos , Molécula 1 de Adesão Intercelular/biossíntese , Interleucina-8/biossíntese , Neutrófilos/metabolismo , Fosforilação , Tirosina/metabolismo , Molécula 1 de Adesão de Célula Vascular/biossíntese
11.
J Toxicol Environ Health A ; 65(14): 1013-24, 2002 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-12133234

RESUMO

Tributyltin (TBT) has frequently been used as a pesticide and in biocidal paints for marine vessels, leading to its presence in the environment. Although TBT was recently found to induce apoptosis in different immune cells, by a mechanism that is not fully established, its effect on neutrophils is not known. In this study, it was found that TBT induced apoptosis in human neutrophils as assessed by cytology, flow cytometry, and degradation of the microfilament-associated protein gelsolin. Furthermore, data showed that TBT induced neutrophil apoptosis by a caspase-dependent mechanism, since addition of z-Val-Ala-Asp(MOe)-CH(2)F (z-VAD-FMK) in the culture prevented the effect of TBT. It was also found that the cytoskeletal proteins gelsolin, paxillin, and vimentin, but not vinculin, were degraded by TBT via caspases, as assessed by immunoblotting. Data indicate that gelsolin, paxillin, and vimentin are three caspase substrates involved in both spontaneous and TBT-induced neutrophil apoptosis. Cells were not necrotic as assessed by trypan blue dye exclusion, and this is in agreement with the absence of vinculin degradation. Evidence indicates that TBT-induced fragmentation of cytoskeletal proteins via caspases is a process that is tightly regulated.


Assuntos
Apoptose/efeitos dos fármacos , Caspases/metabolismo , Neutrófilos/efeitos dos fármacos , Compostos de Trialquitina/toxicidade , Poluentes da Água/toxicidade , Adulto , Membrana Celular/efeitos dos fármacos , Proteínas do Citoesqueleto/efeitos dos fármacos , Relação Dose-Resposta a Droga , Feminino , Gelsolina/efeitos dos fármacos , Humanos , Immunoblotting , Masculino , Paxilina , Fosfoproteínas/efeitos dos fármacos , Compostos de Trialquitina/administração & dosagem , Vimentina/efeitos dos fármacos , Poluentes da Água/administração & dosagem
12.
Clin Immunol ; 104(1): 40-8, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12139946

RESUMO

Chemicals of environmental concern are known to alter the immune system. Recent data indicate that some contaminants possess proinflammatory properties by activating neutrophils, an area of research that is still poorly investigated. We have previously documented that toxaphene activates human neutrophils to produce reactive oxygen species (ROS) and accelerates apoptosis by a yet unknown mechanism. In this study, we found that toxaphene induces another neutrophil function, chemotaxis. Furthermore, we found that toxaphene induces both chemotaxis and apoptosis via a ROS-dependent mechanism, since these responses were blocked by the addition of catalase to the culture. In addition, toxaphene was found to induce the degradation of the cytoskeletal proteins gelsolin, paxillin, and vimentin during apoptosis, and this was reversed by the addition of z-VAD-FMK (caspase inhibitor) or catalase, demonstrating the importance of caspases and ROS in this process. In contrast to toxaphene, we found that beryllium does not induce superoxide production, and, this correlates with its inability to induce chemotaxis and apoptosis. We conclude that toxaphene induces chemotaxis and apoptosis via ROS and that caspases and ROS are involved in the degradation of cytoskeletal proteins.


Assuntos
Apoptose , Berílio/farmacologia , Inibidores de Caspase , Quimiotaxia de Leucócito/fisiologia , Proteínas do Citoesqueleto/metabolismo , Neutrófilos/efeitos dos fármacos , Preparações de Plantas , Proteínas de Plantas , Espécies Reativas de Oxigênio/metabolismo , Toxafeno/farmacologia , Clorometilcetonas de Aminoácidos/farmacologia , Inibidores de Cisteína Proteinase/farmacologia , Radicais Livres , Gelsolina/metabolismo , Humanos , Neutrófilos/metabolismo , Neutrófilos/fisiologia , Paxilina , Fosfoproteínas/metabolismo , Proteínas Inativadoras de Ribossomos Tipo 2 , Superóxidos/metabolismo , Toxinas Biológicas/farmacologia , Vimentina/metabolismo
13.
J Immunol ; 168(3): 1419-27, 2002 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-11801684

RESUMO

Viscum album agglutinin-I (VAA-I) is a plant lectin that possesses interesting potential therapeutic properties and immunomodulatory activities. We have recently found that VAA-I is a potent inducer of human neutrophil apoptosis, but the mechanism(s) involved require further elucidation. In this study, we found that VAA-I alters mitochondrial transmembrane potential and increases intracellular levels of reactive oxygen species (ROS). Despite these observations, treatment with the mitochondrial stabilizer, bongkrekic acid, or with catalase, known to degrade H(2)O(2), fails to reverse VAA-I-induced apoptosis. Moreover, VAA-I was found to induce apoptosis in PLB-985 cells deficient in gp91(phox), indicating that the lectin acts via an ROS-independent mechanism. Pretreatment of neutrophils with brefeldin A, an inhibitor of vesicular transport, was found to reverse VAA-I-induced apoptosis. Protein expression of Mcl-1 was decreased by VAA-I. The role of caspases in the degradation of cytoskeletal proteins during both spontaneous and VAA-I-induced neutrophil apoptosis was also investigated. Paxillin and vimentin were markedly degraded by VAA-I when compared with neutrophils that undergo spontaneous apoptosis, but not vinculin or alpha- and beta-tubulin. Caspases were involved in cytoskeletal protein degradation because preincubation with the pan-caspase inhibitor N-benzyloxycarbonyl-V-A-D-O-methylfluoromethyl ketone was found to reverse protein cleavage. We conclude that VAA-I needs to be internalized to mediate apoptosis and that its activity is not dependent on a cell surface receptor-mediated pathway. Also, we conclude that VAA-I induces apoptosis by ROS-independent and Mcl-1-dependent mechanisms and that caspases are involved in cytoskeletal protein degradation in both spontaneous and VAA-I-induced neutrophil apoptosis.


Assuntos
Apoptose/efeitos dos fármacos , Caspases/fisiologia , Proteínas do Citoesqueleto/metabolismo , Proteínas de Neoplasias/antagonistas & inibidores , Neutrófilos/metabolismo , Fosfoproteínas/metabolismo , Preparações de Plantas , Proteínas de Plantas , Inibidores da Síntese de Proteínas/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2 , Toxinas Biológicas/farmacologia , Vimentina/metabolismo , Brefeldina A/farmacologia , Proteínas do Citoesqueleto/antagonistas & inibidores , Citometria de Fluxo , Humanos , Filamentos Intermediários/efeitos dos fármacos , Filamentos Intermediários/metabolismo , Membranas Intracelulares/efeitos dos fármacos , Membranas Intracelulares/fisiologia , Potenciais da Membrana/efeitos dos fármacos , Microtúbulos/efeitos dos fármacos , Microtúbulos/metabolismo , Erva-de-Passarinho , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/fisiologia , Proteína de Sequência 1 de Leucemia de Células Mieloides , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/metabolismo , Neutrófilos/citologia , Neutrófilos/efeitos dos fármacos , Neutrófilos/enzimologia , Paxilina , Fosfoproteínas/antagonistas & inibidores , Espécies Reativas de Oxigênio/metabolismo , Proteínas Inativadoras de Ribossomos , Proteínas Inativadoras de Ribossomos Tipo 2 , Células Tumorais Cultivadas , Regulação para Cima/efeitos dos fármacos , Vimentina/antagonistas & inibidores
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA