Department of Public Health, Hyogo College of Medicine, 1-1 Mukogawacho, 663-8501, Nishinomiya, Japan,
Environ Health Prev Med. 2007 May;12(3):138-42. doi: 10.1007/BF02898028.
Particulate air pollution is a serious problem all over the world, and the development of a method to evaluate the health effects of ambient particles is necessary. In this study, cells cultured in vitro were exposed to particles sampled at the side of a main road, and their protein expression levels were examined.
Ambient particles were collected at the side of a main road using a high-volume air sampler. Some of the collected particles (crude particles) were treated with an organic solvent to remove chemical components, and the resulting residues were used as residual particles. Cells from the mouse alveolar epithelial cell line LA-4 were inoculated into tissue-culture dishes at 1.4×10(4)/cm(2), exposed to each type of particle or artificial carbon particles (Printex 90) that were dispersed using an ultrasonic homogenizer by mixing in the medium twice at 24 and 48 hours, and incubated for up to 72 hours after the start of inoculation. After exposure, the number of cells and intracellular dehydrogenase activity were measured. Proteins extracted from the cells were subjected to two-dimensional gel electrophoresis with isoelectric focusing at pHs 4-7 using a 10% acrylamide gel, and their expression levels were analyzed after fluorescent staining.
The intracellular dehydrogenase activity of the cells significantly decreased as a result of exposure to the residual (0.70-fold) and crude (0.84-fold) particles compared with that of the control, but it showed no change as a result of exposure to Printex 90. The protein expression levels in the cells exposed to the particles increased or decreased similarly, but different expression levels were also observed. There were differences in the effects observed between the cells exposed to the artificial carbon particles and those exposed to particles collected from ambient air.
This study indicates that protein expression levels in cells change in response to exposure to particles collected from ambient air. To evaluate the effects of particles on health, it is considered necessary to use particles collected from ambient air.
颗粒物污染是全世界面临的一个严重问题，因此有必要开发一种评估环境颗粒物健康影响的方法。本研究采用体外细胞培养方法，将细胞暴露于采集自主要交通道路旁的颗粒物，检测细胞的蛋白表达水平。
采用大容量采样器在主要交通道路旁采集环境颗粒物。采集的部分颗粒物（粗颗粒物）用有机溶剂处理，去除化学组分，得到的残余物作为残余颗粒物。将小鼠肺泡上皮细胞系 LA-4 的细胞以 1.4×10(4)/cm(2)的密度接种于组织培养皿中，分别用各类型颗粒物（或人工碳颗粒物，如超声匀浆法分散的 Printex 90）进行处理，在培养液中分别于 24 小时和 48 小时时混合 2 次，接种后培养至 72 小时。暴露后，检测细胞数和细胞内脱氢酶活性。用 10%丙烯酰胺凝胶在 pH4-7 进行等电聚焦二维凝胶电泳，荧光染色后分析蛋白表达水平。
与对照组相比，细胞内脱氢酶活性因暴露于残余颗粒物（降低 70%）和粗颗粒物（降低 84%）而显著降低，但因暴露于 Printex 90 而无变化。暴露于颗粒物的细胞蛋白表达水平增加或减少的情况相似，但也观察到不同的表达水平。暴露于人工碳颗粒物的细胞和暴露于采集自环境空气的颗粒物的细胞的影响存在差异。
本研究表明，细胞对采集自环境空气的颗粒物的暴露会导致蛋白表达水平发生变化。为了评估颗粒物对健康的影响，认为有必要使用采集自环境空气的颗粒物。
