肺部上皮內襯液體對於微粒引起氧化傷害之影響

Effect of pulmonary epithelial lining fluid on PM-induced oxidative damage

鄭伊玲(Yi-Ling Cheng)

指導教授 ： 鄭尊仁

國立臺灣大學/公共衛生學院/職業醫學與工業衛生研究所/碩士(2004年)

https://doi.org/10.6342/NTU.2004.00137

摘要

過去研究指出，暴露微粒污染物會引起肺部細胞氧化壓力增加，進一步引發發炎反應，然而大氣微粒組成複雜，究竟是何種成分引起細胞毒性有待釐清。過去研究發現細胞暴露在超細粒徑微粒或含有多種組成的汽機車燃燒微粒都能引起細胞產生氧化性物種（Reactive Oxygen Species, ROS），造成氧化壓力的上升。然而人類肺部表面具有多種抗氧化成分的上皮內襯液體（epithelial lining fluid; ELF），能與進入呼吸道的微粒污染物反應減少細胞氧化傷害，但其影響機制並不清楚。本研究目的為探討肺部上皮內襯液體對於各種微粒污染物成分引起細胞氧化傷害的影響。
我們以非細胞系統及細胞系統進行暴露實驗並參考Guobin等人的研究，配製人類肺部上皮內襯液體進行實驗。在非細胞系統中進行各種微粒污染物暴露後的ROS量測，而在細胞系統中利用轉移盤（transwell）進行細胞實驗，在transwell上添加人類肺部上皮內襯液體與肺泡上皮細胞（A-549），測量各種微粒成分與細胞反應後產生之ROS、評估細胞DNA單股斷裂情形及發炎前趨物IL-8量測。微粒濃度方面，選用能產生ROS的最小濃度進行實驗，在超細粒徑碳黑微粒（ufCB）0, 50, 150

關鍵字

肺部上皮內襯液體 ； 反應性氧化物種 ； 大氣微粒

並列摘要

Previous studies have reported that exposure to particulate matter（PM）induces oxidative stress and respiratory tract inflammation. The component of PM responsible for this health effect remained unclear. Pulmonary epithelial lining fluid（ELF）consists of various antioxidants, which can protect lung cells against the oxidative damage of PM. However the exact mechanism remains unclear. The aim of this study was to determine the effect of ELF on PM-induced oxidative damage.
This study was conducted with and without epithelial cells. We also use synthetic human epithelial lining fluids (ELF, Guobin et al., 1999.) in both cell and cell free system. In cell free system, total ROS was measured with DCFH assay after exposure to ultrafine carbon black (ufCB; at 0, 50, 150ug/ml), transitional metal (FeSO4; at 0,100, 500uM) and organic component（DEP extract; at 0, 25, 50ug/ml）. Subsequently, we established an in vitro transwells exposure system consisting with or without of ELF. A549 cells were exposed to particles for four hours. ROS was then measured using DCFH assay and DNA breakage was determined by single-cell gel electrophoreses (Comet assay).
The results indicated that in cell free system, the amounts of ROS increased with exposure concentration and exposure time. ELF significantly decreased ROS by 100% 、56.5% and 1% as compared to culture medium after ufCB、FeSO4 or DEP extract exposure（p<0.05）. Furthermore, in cell system, ROS decreased 91%、 83%and 1% with the treatment of ELF compared to culture medium after cells exposed to ufCB 、FeSO4 and DEP extract. ELF also can decrease DNA single-strand breakage. Furthermore, there was no difference on IL-8 secretion after exposure to different componemts.
Our results suggest that ELF can decrease total ROS induced by ultrafine carbon black、FeSO4 and DEP extract. Therefore ELF can protect A549 cells from oxidative damage.

並列關鍵字

Reactive oxygen species (ROS) ； Epithelial lining fluid（ELF） ； Particulate matter（PM）

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