IRON, CALCIUM AND OXIDATIVE STRESS IN LUNG INJURY

尽管不同煤矿地区的粉尘暴露水平相当，但煤矿工人尘肺病和慢性阻塞性支气管肺病的患病率存在显著差异。本研究的目的是验证生物可利用的Fe2+是煤尘氧化应激途径细胞损伤的活性成分，而方解石（CaCO）可能通过抑制Fe2+的溶解作用，使Fe2+的生物可利用性降低，从而在这种损伤中发挥保护作用。豚鼠肺泡巨噬细胞（AMs）和人肺II型细胞（A549）的原代培养将用于煤处理。将对来自三个煤矿地区的30个煤样本进行测试，CWP患病率分别为4%（犹他州），10%（西弗吉尼亚州）和26%（宾夕法尼亚州）。测定这些细胞中煤尘释放的Fe2+、Ca2+以及其他微量金属（as、Cd、Ni、Zn、Co、Cu）和石英的生物利用度。铁蛋白和金属硫蛋白将作为这些细胞中铁离子和微量金属的生物利用度的指标。细胞Fe2+和Ca2+水平也将使用比色法确定。低温灰化晶胞基质后，用x射线衍射测定晶胞中的石英含量。测定煤处理前后细胞膜脂质过氧化、H2O2形成及AP-1表达。肿瘤坏死因子- α (tnf - α)、白细胞介素-1 （IL-1）和纤维连接蛋白的水平也将作为本研究的一部分进行测定。以tnf - α、IL-1等生化参数为自变量，通过多元回归分析确定生物可利用性Fe2+、微量金属和石英的独立效应。在细胞处理之前，将预先确定百分比的方解石添加到宾夕法尼亚州和西弗吉尼亚州的煤中。AMs和A549细胞在暴露于未处理的煤之前也将用Ca2+预处理。将测量上述终点并评估治疗效果。我们期望，通过确认Fe2+在煤致损伤中的作用，我们将能够预测哪种煤可能毒性更大，甚至在开采之前。通过确定方解石的作用，有可能提出预防肺部疾病的替代方法。

Striking differences in the prevalence of coal workers' pneumoconiosis and chronic obstructive bronchopneumopathy exist between different coal mine regions despite comparable levels of dust exposure. The goal of this proposal is to test the hypothesis that bio-available Fe2+ is the active component in coal dust-induced cell injury through oxidative stress pathway, and that calcite (CaCO) may play a protective role in such injury by inhibiting solubilization of Fe2+, making Fe2+ less bio- available. Primary cultures of guinea pig alveolar macrophages (AMs) and human lung type II cells (A549) will be used for coal treatments. Total of thirty coal samples from three coal mine regions with a CWP prevalence of 4 percent (Utah), 10 percent (West Virginia), and 26 percent (Pennsylvania), respectively, will be tested. The bio-availability of Fe2+ and Ca2+, as well as other trace metals (i.e. As, Cd, Ni, Zn, Co, Cu) and quartz released from coal dusts in these cells will be determined. Ferritin and metallothionein will be measured as indices of the bio-availability of Fe2+ and trace metals in these cells. Cellular Fe2+ and Ca2+ levels will also be determined using colorimetric methods. Quartz content in the cells will be quantitated using X-ray diffraction after low temperature ashing of cell matrix. Lipid peroxidation of cell membranes, H2O2 formation, and AP-1 expression will be measured before and after treatment with coals. The levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1), and fibronectin will also be determined as a part of this study. Using TNF-alpha, IL-1, and other biochemical parameters as independent variables, the independent effect of bio-available Fe2+, trace metals, and quartz will be identified by multiple regression analyses. A pre-determined percentage of calcite will be added to the Pennsylvania and West Virginia coals before cell treatment. AMs and A549 cells will also be pretreated with Ca2+ before exposure to the untreated coals. The above mentioned end-points will be measured and effects of treatments assessed. We expect that, by confirming the role of Fe2+ in coal-induced injury, we will be able to predict which coal is likely to be more toxic, even before mining. By determining the role of calcite, it is possible to propose alternative methods for lung disease prevention.