Exposure to diesel exhaust up-regulates iNOS expression in ApoE knockout mice.
Toxicol Appl Pharmacol
; 255(2): 184-92, 2011 Sep 01.
Article
em En
| MEDLINE
| ID: mdl-21722660
ABSTRACT
UNLABELLED Traffic related particulate matter air pollution is a risk factor for cardiovascular events; however, the biological mechanisms are unclear. We hypothesize that diesel exhaust (DE) inhalation induces up-regulation of inducible nitric oxide synthase (iNOS), which is known to contribute to vascular dysfunction, progression of atherosclerosis and ultimately cardiovascular morbidity and mortality. METHODS:
ApoE knockout mice (30-week) were exposed to DE (at 200 µg/m³ of particulate matter) or filtered-air (control) for 7 weeks (6 h/day, 5 days/week). iNOS expression in the blood vessels and heart was evaluated by immunohistochemistry and western blotting analysis. To examine iNOS activity, thoracic aortae were mounted in a wire myograph, and vasoconstriction stimulated by phenylephrine (PE) was measured with and without the presence of the specific inhibitor for iNOS (1400 W). NF-κB (p65) activity was examined by ELISA. The mRNA expression of iNOS and NF-κB (p65) was determined by real-time PCR.RESULTS:
DE exposure significantly enhanced iNOS expression in the thoracic aorta (4-fold) and heart (1.5 fold). DE exposure significantly attenuated PE-stimulated vasoconstriction by ~20%, which was partly reversed by 1400 W. The mRNA expression of iNOS and NF-κB was significantly augmented after DE exposure. NF-κB activity was enhanced 2-fold after DE inhalation, and the augmented NF-κB activity was positively correlated with iNOS expression (R²=0.5998).CONCLUSIONS:
We show that exposure to DE increases iNOS expression and activity possibly via NF-κB-mediated pathway. We suspect that DE exposure-caused up-regulation of iNOS contributes to vascular dysfunction and atherogenesis, which could ultimately lead to urban air pollution-associated cardiovascular morbidity and mortality.
Texto completo:
1
Coleções:
01-internacional
Contexto em Saúde:
6_ODS3_enfermedades_notrasmisibles
Base de dados:
MEDLINE
Assunto principal:
Apolipoproteínas E
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Emissões de Veículos
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Aterosclerose
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Óxido Nítrico Sintase Tipo II
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Material Particulado
Tipo de estudo:
Risk_factors_studies
Limite:
Animals
Idioma:
En
Revista:
Toxicol Appl Pharmacol
Ano de publicação:
2011
Tipo de documento:
Article