北京大气PM_(2.5)对A549细胞炎性因子及DNA损伤的毒性

为探讨大气PM_(2.5)及其不同组分对人肺上皮细胞A549的毒性作用及其剂量-反应关系,将前期采集的PM_(2.5)颗粒物用不同方法进一步制备PM_(2.5)水溶性组分、PM_(2.5)脂溶性组分和PM_(2.5)单纯颗粒物,将制备的PM_(2.5)颗粒物及其组分以不同浓度(10,50,100,200,400μg/m L)对A549细胞染毒,用MTS法分别在染毒6,10,24,48,72h后测定细胞活力,染毒24h后用ELISA及RT-QPCR法测定炎性因子IL-6和TNF-α表达量,AP位点计数法测定细胞DNA损伤情况.结果表明:除PM_(2.5)水溶性组分外,其余染毒样本高浓度染毒时始终对细胞生长表现出抑制作用,其中低浓度染毒时可在较短时间对细胞生长表现出抑制作用,染毒时间较长时抑制作用减弱或消失,PM_(2.5)水溶性组分对细胞生长抑制作用并不显著;除PM_(2.5)水溶性组分外,其余染毒样本都显著升高了IL-6m RNA的相对表达量和IL-6蛋白的分泌,除PM_(2.5)脂溶性组分外,其余染毒样本都显著升高了TNF-αm RNA的相对表达量;除PM_(2.5)水溶性组分外,其余染毒样本都显著提高了DNA碱基缺失程度.总的来说,PM_(2.5)水溶性组分在抑制细胞活力、造成炎性损伤及DNA损伤方面作用相对较小,而PM_(2.5)所产生的毒性作用并不仅限于其所吸附的复杂成分,其中作为载体的固体核心颗粒对机体可能造成的毒性作用也不容忽视.

Toxicological study at inflammatory factors and DNA damages effects of Beijing atmospheric PM2.5 and its different fractions to pulmonary epithelial cells A549 of human

In order to investigate the toxicity effect of atmospheric PM_2.5 and its different fractions to human pulmonary epithelial cells A549 with respect to the relationship between PM_2.5 dosage and cell response, the water-soluble, fat-soluble, pure particle fractions of PM_2.5 (designated WSP_2.5, FSP_2.5 and PPP_2.5, respectively) prepared from original PM_2.5 samples (designated OP_2.5) and OP_2.5 were to treat A549 cells at different PM concentrations (10, 50, 100, 200, 400μg/mL, respectively). The MTS method was used to test the cell viability at 6h, 10h, 24h, 48h and 72h post-treatment, while ELISA and RT-QPCR were employed to detect the production of inflammatory cytokines IL-6 and TNF-α and the AP-sites counting was conducted to determine the level of intracellular DNA damage at 24h post-treatment. WSP_2.5 had very limited effect to inhibit cell growth and induce inflammatory damages and DNA base deletion. FSP_2.5, PPP_2.5 and OP_2.5 at high concentrations showed the inhibitory effect to cell growth across treatment; when cells were treated with low concentrations of FSP_2.5, PPP_2.5 or OP_2.5, the inhibition of cell growth occurred within a short period and then disappeared over time. FSP_2.5, PPP_2.5 and OP_2.5 treatment significantly induced the production of IL-6at both mRNA and protein levels, while WSP_2.5, PPP_2.5 and OP_2.5 treatment significantly induced the mRNA expression of TNF-α. FSP_2.5, PPP_2.5 and OP_2.5 treatment also induced the considerable DNA base deletion. In a word, not only the complex components adsorbed on the solid core granules of PM_2.5, but also the solid core granules themselves contributed to the cytotoxicity effects.