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1.
Nanotoxicology ; 5(1): 66-78, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21417689

RESUMEN

We have investigated whether short-term nose-only inhalation exposure to electric spark discharge-generated carbon nanoparticles (∼60 nm) causes oxidative stress and DNA damage responses in the lungs of rats (152 µg/m(3); 4 h) and mice (142 µg/m(3); 4 h, or three times 4 h). In both species, no pulmonary inflammation and toxicity were detected by bronchoalveolar lavage or mRNA expression analyses. Oxidative DNA damage (measured by fpg-comet assay), was also not increased in mouse whole lung tissue or isolated lung epithelial cells from rat. In addition, the mRNA expressions of the DNA base excision repair genes OGG1, DNA Polß and XRCC1 were not altered. However, in the lung epithelial cells isolated from the nanoparticle-exposed rats a small but significant increase in APE-1 mRNA expression was measured. Thus, short-term inhalation of carbon nanoparticles under the applied exposure regimen, does not cause oxidative stress and DNA damage in the lungs of healthy mice and rats.


Asunto(s)
Contaminantes Atmosféricos/toxicidad , Carbono/toxicidad , Exposición por Inhalación/efectos adversos , Pulmón/efectos de los fármacos , Nanopartículas/toxicidad , Estrés Oxidativo , Animales , Líquido del Lavado Bronquioalveolar/citología , Daño del ADN , Relación Dosis-Respuesta a Droga , Femenino , Exposición por Inhalación/análisis , Pulmón/metabolismo , Pulmón/fisiopatología , Masculino , Ratones , Ratones Endogámicos C57BL , ARN Mensajero/metabolismo , Ratas , Ratas Endogámicas F344 , Mucosa Respiratoria/efectos de los fármacos , Mucosa Respiratoria/metabolismo
2.
Free Radic Biol Med ; 49(11): 1685-93, 2010 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-20828610

RESUMEN

The carcinogenicity of respirable quartz is considered to be driven by reactive oxygen species (ROS) generation in association with chronic inflammation. The contribution of phagocyte-derived ROS to inflammation, oxidative stress, and DNA damage responses was investigated in the lungs of C57BL/6J wild-type and p47(phox-/-) mice, 24h after pharyngeal aspiration of DQ12 quartz (100 mg/kg bw). Bone-marrow-derived neutrophils from wild-type and p47(phox-/-) mice were used for parallel in vitro investigations in coculture with A549 human alveolar epithelial cells. Quartz induced a marked neutrophil influx in both wild-type and p47(phox-/-) mouse lungs. Significant increases in mRNA expression of the oxidative stress markers HO-1 and γ-GCS were observed only in quartz-treated wild-type animals. Oxidative DNA damage in lung tissue was not affected by quartz exposure and did not differ between p47(phox-/-) and WT mice. Differences in mRNA expression of the DNA repair genes OGG1, APE-1, DNA Polß, and XRCC1 were also absent. Quartz treatment of cocultures containing wild-type neutrophils, but not p47(phox-/-) neutrophils, caused increased oxidative DNA damage in epithelial cells. Our study demonstrates that neutrophil-derived ROS significantly contribute to pulmonary oxidative stress responses after acute quartz exposure, yet their role in the associated induction of oxidative DNA damage could be shown only in vitro.


Asunto(s)
Daño del ADN , Neutrófilos/metabolismo , Estrés Oxidativo/efectos de los fármacos , Cuarzo/efectos adversos , Especies Reactivas de Oxígeno/farmacología , Animales , Células Cultivadas , Técnicas de Cocultivo , Reparación del ADN/efectos de los fármacos , Reparación del ADN/genética , Humanos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , NADPH Oxidasas/genética , NADPH Oxidasas/metabolismo , Nanopartículas/efectos adversos , Neumonía/etiología , Neumonía/genética , Neumonía/metabolismo , Neumonía/patología , Especies Reactivas de Oxígeno/metabolismo
3.
Environ Sci Technol ; 44(9): 3539-45, 2010 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-20355702

RESUMEN

Exposure to ambient particulate matter (PM) is associated with respiratory and cardiovascular disease and lung cancer. In this study, we used size fractionated PM samples (3-7, 1.5-3, 0.95-1.5, 0.5-0.95, and <0.5 microm), collected at four contrasting locations (three urban sites, one remote background) in the UK with a Sierra-Andersen high volume cascade impactor. The H(2)O(2)-dependent oxidant generating capacity of the samples was determined by electron spin resonance with 5,5-dimethyl-1-pyrroline-N-oxide spin trapping. In A549 human lung epithelial cells, we determined the cytotoxicity of samples by LDH assay, and interleukin-8 (IL-8) release as an indicator of their inflammatory potency. Oxidative DNA damage was measured by the formamido-pyrimidine-glycosylase (fpg)-modified comet assay. Marked contrasts were observed for all endpoints. Remote background PM showed the lowest oxidant potential, was neither cytotoxic nor genotoxic and did not increase IL-8 release. For the other samples, effects were found to depend more on sampling location than on size fraction. PM collected at high-traffic locations generally showed the strongest oxidant capacity and toxicity. Significant correlations were observed between the oxidant generating potential and all toxicological endpoints investigated, which demonstrates that measurement of the oxidant generating potential by ESR represents a sensitive method to estimate the toxic potential of PM.


Asunto(s)
Células Epiteliales/química , Pulmón/citología , Oxidantes/química , Material Particulado/química , Línea Celular Tumoral , Ensayo Cometa , Daño del ADN , Ensayo de Inmunoadsorción Enzimática , Humanos , Peróxido de Hidrógeno/química , Interleucina-8/metabolismo , Pulmón/metabolismo , Estrés Oxidativo , Oxígeno/química , Tamaño de la Partícula , Detección de Spin
4.
J Exp Biol ; 210(Pt 20): 3636-43, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17921165

RESUMEN

The chitin portion of the peritrophic matrix in the midgut of the tobacco hornworm, Manduca sexta, is produced by chitin synthase 2 (CHS2), a transmembrane family II glycosyltransferase, located at the apical tips of brush border microvilli. To look for proteins that potentially interact with CHS2, we performed yeast two-hybrid screening, identifying a novel chymotrypsin-like protease (CTLP1) that binds to the extracellular carboxyterminal domain of CHS2. The occurrence of this interaction in vivo is supported by co-localization and co-immunoprecipitation data. Based on our findings we propose that chitin synthesis is controlled by an intestinal proteolytic signalling cascade linking chitin synthase activity to the nutritional state of the larvae.


Asunto(s)
Quitina Sintasa/metabolismo , Quimasas/metabolismo , Sistema Digestivo/enzimología , Manduca/enzimología , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Quitina/biosíntesis , Quitina Sintasa/química , Quitina Sintasa/genética , Quimasas/química , Quimasas/genética , ADN Complementario/genética , ADN Complementario/aislamiento & purificación , Sistema Digestivo/citología , Regulación Enzimológica de la Expresión Génica , Inmunohistoquímica , Inmunoprecipitación , Manduca/citología , Manduca/genética , Datos de Secuencia Molecular , Unión Proteica , Estructura Terciaria de Proteína , Transporte de Proteínas , ARN Mensajero/genética , ARN Mensajero/metabolismo , Análisis de Secuencia de ADN , Técnicas del Sistema de Dos Híbridos
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