Stone William L, Qui Min, Smith Milton
Department of Pediatrics, East Tennessee State University, Johnson City, Tennessee 37614-0578, USA.
BMC Cell Biol. 2003 Jan 6;4:1. doi: 10.1186/1471-2121-4-1.
The bacterial endotoxin, lipopolysaccharide (LPS), is a well-characterized inflammatory factor found in the cell wall of Gram-negative bacteria. In this investigation, we studied the cytotoxic interaction between 2-chloroethyl ethyl sulfide (CEES or ClCH2CH2SCH2CH3) and LPS using murine RAW264.7 macrophages. CEES is a sulfur vesicating agent and is an analog of 2,2'-dichlorodiethyl sulfide (sulfur mustard). LPS is a ubiquitous natural agent found in the environment. The ability of LPS and other inflammatory agents (such as TNF-alpha and IL-1beta) to modulate the toxicity of CEES is likely to be an important factor in the design of effective treatments.
RAW 264.7 macrophages stimulated with LPS were found to be more susceptible to the cytotoxic effect of CEES than unstimulated macrophages. Very low levels of LPS (20 ng/ml) dramatically enhanced the toxicity of CEES at concentrations greater than 400 microM. The cytotoxic interaction between LPS and CEES reached a maximum 12 hours after exposure. In addition, we found that tumor necrosis factor-alpha (TNF-alpha) and interleukin-1-beta (IL-1-beta) as well as phorbol myristate acetate (PMA) also enhanced the cytotoxic effects of CEES but to a lesser extent than LPS.
Our in vitro results suggest the possibility that LPS and inflammatory cytokines could enhance the toxicity of sulfur mustard. Since LPS is a ubiquitous agent in the natural environment, its presence is likely to be an important variable influencing the cytotoxicity of sulfur mustard toxicity. We have initiated further experiments to determine the molecular mechanism whereby the inflammatory process influences sulfur mustard cytotoxicity.
细菌内毒素脂多糖（LPS）是革兰氏阴性菌细胞壁中一种特性明确的炎症因子。在本研究中，我们使用小鼠RAW264.7巨噬细胞研究了2-氯乙基乙硫醚（CEES或ClCH2CH2SCH2CH3）与LPS之间的细胞毒性相互作用。CEES是一种硫起泡剂，是2,2'-二氯二乙硫醚（芥子气）的类似物。LPS是环境中普遍存在的天然物质。LPS和其他炎症因子（如肿瘤坏死因子-α和白细胞介素-1β）调节CEES毒性的能力可能是有效治疗设计中的一个重要因素。
发现用LPS刺激的RAW 264.7巨噬细胞比未刺激的巨噬细胞对CEES的细胞毒性作用更敏感。极低水平的LPS（20 ng/ml）在浓度大于400 microM时显著增强了CEES的毒性。LPS与CEES之间的细胞毒性相互作用在暴露后12小时达到最大值。此外，我们发现肿瘤坏死因子-α（TNF-α）、白细胞介素-1-β（IL-1-β）以及佛波酯（PMA）也增强了CEES的细胞毒性作用，但程度低于LPS。
我们的体外研究结果表明，LPS和炎症细胞因子可能增强芥子气的毒性。由于LPS是自然环境中普遍存在的物质，其存在可能是影响芥子气毒性细胞毒性的一个重要变量。我们已开展进一步实验以确定炎症过程影响芥子气细胞毒性的分子机制。
