高原城市室内灰尘对人角膜上皮细胞损伤研究

Damage to human corneal epithelial cells caused by indoor dust in plateau city

收集高海拔城市昆明不同功能区室内灰尘,利用等离子发射光谱仪分析不同粒径(F1~F4:100~2000,75~100,63~75,45~63μm)灰尘中Pb,Cu,Cd,Zn,Cr,Ni,Co,As和Mn的含量,借助人工泪液提取的方法,测定目标重金属的可溶出率(生物可给性),并分析室内灰尘人工泪提取液对人角膜上皮细胞的毒性效应.结果表明,办公室灰尘中Ni,Mn,Zn显著高于家庭及学生宿舍(P<0.01),且Cd,Ni,Zn的含量高于昆明市土壤背景值的39.3、9.5、12.3倍.居民住宅Co(10.6%)、办公室As(16.1%)及学生宿舍Mn(36.0%)溶出率最高.重金属元素在粒径分布规律上表现出不同特征,办公室及宿舍灰尘重金属易在63~100μm粒径范围内富集.人角膜上皮细胞经室内灰尘人工泪提取液暴露24h后,低浓度(20μg/mL)、高浓度(1280μg/mL)分别促进和抑制细胞增殖,与对照组相比较均具有统计学意义(P<0.05).细胞炎症因子IL-1β和TNF-α相对表达量显著增加,提示昆明室内灰尘暴露有诱发角膜炎症疾病发生的风险.

The indoor dust samples were collected from houses,office,and dormitory in a typical high-altitude city Kunming.Each sample was separated into 4size fractions(F1~F4:100~2000,75~100,63~75,45~63μm),and the concentrations of nine heavy metals(Pb,Cu,Cd,Zn,Cr,Ni,Co,As,and Mn)in indoor dust were detected using ICP-OES.In addition,the solubility rates(bioaccessibility)of the target heavy metals in artificial tears extraction and their cytotoxicity on human corneal epithelial cells(HCECs)were determined.The results showed that Ni,Mn,and Zn in office dust were significantly higher than those in residence and dormitory dust(P<0.01),and the contents of Cd,Ni,and Zn were 39.3,9.5 and 12.3times higher than the background values of Kunming soils.The solubility rates of Co in residence dust,As in office dust and Mn in dormitory dust were the highest at 10.6%,16.1%,and 36%,respectively.Heavy metals were highly susceptible to accumulate in office and dormitory dust with particle size ranging from 63 to 100μm.Moreover,the typical polygonal and cobblestone appearance of HCECs became spindle shape after artificial tear extracts of office dust exposure.Cell proliferation was enhanced at 20μg/mL whereas inhibited at higher concentration(P<0.05).The elevated mRNA expression of pro-inflammatory mediators(IL-1βand TNF-α)suggested that indoor dust from Kunming may pose a risk to inducing human corneal inflammation.