| Summary: | 碩士 === 中國醫藥大學 === 基礎醫學研究所碩士班 === 100 === Nanoparticles (NPs) were widely employed in our living environments. Among
those NPs, zinc oxide nanoparticles (ZnONPs) were commonly used in cosmetics
because of the excellent protective effect to ultraviolet. Moreover, ZnONPs also have
been used in numerous fields to prevent microbial growth. Nontypeable Haemophilus
influenzae (NTHi) is an extracellular Gram-negative and coccobacilli bacteria lacking
of capsule that frequently colonizes human respiratory mucosa and often produces
localized respiratory tract diseases. Recently, several reports indicated inhalation of
ZnONPs may be a risk factor for human health. But only few researches discussed the
relationship between NPs and immune responses. In this study, we used in vitro and
in vivo platforms to assess the potential effect of NTHi clearance after exposure with
ZnONPs. Our data showed that after infection of mice with 1×10
7
NTHi, which
survived in bronchial alveolar lavage fluids (BALF) and lung tissues, and the
inflammatory cells were infiltrated in lung. After exposure with 140 μg/ml ZnONPs
and ZnOMPs for 14 days, we found that the total numbers of inflammatory cells in
BALF and lung did not show obviously change compared to only infection with
NTHi group. However, our data showed that the numbers of active macrophages and
inducible nitric oxide synthase (iNOS) expression were significantly decreased in
BALF. In addition, we found that 10 μg/ml ZnONPs reduced macrophage
extracellular clearance of NTHi and inhibited nitric oxide production in RAW264.7
cells. Our findings reveal that ZnONPs impair NO production and macrophage
activation which may lead to reduce the NTHi clearance.
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