Sawyer R T, Fadok V A, Kittle L A, Maier L A, Newman L S
Division of Environmental and Occupational Health Sciences, Department of Medicine, D309 Neustadt, National Jewish Medical and Research Center, 1400 Jackson Street, Denver, CO 80206, USA.
Toxicology. 2000 Aug 21;149(2-3):129-42. doi: 10.1016/s0300-483x(00)00237-7.
In vitro stimulation of bronchoalveolar lavage cells from patients with chronic beryllium disease (CBD) induces the production of TNF-alpha. We tested the hypothesis that beryllium (Be)-stimulated TNF-alpha might induce apoptosis in mouse and human macrophage cell lines. These cell lines were selected because they produce a range of Be-stimulated TNF-alpha. The mouse macrophage cell line H36.12j produces high levels of Be-stimulated TNF-alpha. The mouse macrophage cell line P388D.1 produces low, constitutive, levels of TNF-alpha and does not up-regulate Be-stimulated TNF-alpha production. The DEOHS-1 human CBD macrophage cell line does not produce constitutive or Be-stimulated TNF-alpha. Apoptosis was determined by microscopic observation of propidium iodide stained fragmented nuclei in unstimulated and BeSO(4)-stimulated macrophage cell lines. BeSO(4) induced apoptosis in all macrophage cell lines tested. Beryllium-stimulated apoptosis was dose-responsive and maximal after 24 h of exposure to 100 microM BeSO(4). In contrast, unstimulated and Al(2)(SO(4))(3)-stimulated macrophage cell lines did not undergo apoptosis. The general caspase inhibitor BD-fmk inhibited Be-stimulated macrophage cell line apoptosis at concentrations above 50 microM. Our data show that Be-stimulated macrophage cell line apoptosis was caspase-dependent and not solely dependent on Be-stimulated TNF-alpha levels. We speculate that the release of Be-antigen from apoptotic macrophages may serve to re-introduce Be material back into the lung microenvironment, make it available for uptake by new macrophages, and thereby amplify Be-stimulated cytokine production, promoting ongoing inflammation and granuloma maintenance in CBD.
体外刺激慢性铍病（CBD）患者的支气管肺泡灌洗细胞可诱导肿瘤坏死因子-α（TNF-α）的产生。我们检验了以下假设：铍（Be）刺激产生的TNF-α可能诱导小鼠和人类巨噬细胞系发生凋亡。选择这些细胞系是因为它们产生一系列受Be刺激的TNF-α。小鼠巨噬细胞系H36.12j产生高水平的受Be刺激的TNF-α。小鼠巨噬细胞系P388D.1产生低水平的、组成性的TNF-α，并且不会上调受Be刺激的TNF-α产生。DEOHS-1人类CBD巨噬细胞系不产生组成性的或受Be刺激的TNF-α。通过显微镜观察未刺激的和经硫酸铍（BeSO₄）刺激的巨噬细胞系中碘化丙啶染色的碎片化细胞核来确定凋亡情况。BeSO₄在所有测试的巨噬细胞系中均诱导凋亡。铍刺激的凋亡具有剂量依赖性，在暴露于100微摩尔BeSO₄ 24小时后达到最大值。相比之下，未刺激的和经硫酸铝（Al₂(SO₄)₃）刺激的巨噬细胞系未发生凋亡。通用的半胱天冬酶抑制剂BD-fmk在浓度高于50微摩尔时可抑制受Be刺激的巨噬细胞系凋亡。我们的数据表明，受Be刺激的巨噬细胞系凋亡是半胱天冬酶依赖性的，并非仅依赖于受Be刺激的TNF-α水平。我们推测，凋亡巨噬细胞中Be抗原的释放可能有助于将Be物质重新引入肺微环境，使其可供新的巨噬细胞摄取，从而放大受Be刺激的细胞因子产生，促进CBD中持续的炎症和肉芽肿维持。
