Molecular biological study of leukotoxin and its diol-induced cell activation and injury -experimental model of ARDS-

我们之前报道过白细胞毒素（Lx），一种亚油酸盐的环氧化物，它激活肺血管内皮一氧化氮合酶和黄嘌呤氧化酶，分别产生一氧化氮和O-，可能损伤细胞。我们想知道 Lx 是否可以激活中性粒细胞和肺泡巨噬细胞、炎症吞噬细胞。我们还想知道Lx的环氧二醇（一种据报道是一种重要的细胞毒性物质的Lx-二醇）是否真的对肺血管内皮细胞发挥毒性。为了回答这些问题，我们使用人中性粒细胞（PMN）、大鼠肺泡巨噬细胞（Mac）、人肺动脉内皮细胞（HPAEC）和中国仓鼠卵巢细胞（CHO）测试了实验。 Lx 和 Lx-二醇通过百日咳毒素敏感信号转导引起 PMN 的有效趋化性，而不表达 CDIIb 或 CD18 粘附分子或产生过氧化物。 TSO 诱导的细胞毒性在人可溶性环氧化物水解酶 (hsEH) cDNA 转染的 CHO 中减弱。由于TSO-二醇损伤了谷胱甘肽耗尽的hsEH cDNA转染的CHO，因此谷胱甘肽是对抗环氧化物二醇诱导的损伤的必需物质。我们目前的研究表明 Lx 及其二醇会引发炎症，并进一步表明谷胱甘肽耗尽的病理状态（例如急性肺损伤，包括 ARDS）可能会增强 Lx 和 Lx-二醇的细胞毒性。

We previously reported that leukotoxin (Lx), an epoxide of linolate, which activated pulmonary vascular endothelial nitric oxide synthase and xanthine oxidase, producing nitric oxide and OィイD22ィエD2-respectively, potentially injured cells. We wondered whether Lx could activate neutrophils and alveolar macrophage, inflammatory phagocytic cells. We also wondered whether epoxide-diol of Lx, a Lx-diol which was reported to be an important cellular toxic substance, realy exert its toxicity in pulmonary vascular endothelial cells. To answer these questions we tested the experiments using human neutrophils (PMN), rat alveolar macrophage (Mac), human pulmonary artery endothelial cell (HPAEC) and chinese hamster ovary cell (CHO). Lx and Lx-diol caused potent chemotaxis of PMN via pertussis toxin-sensitive signal transduction without expression of CDIIb or CD18 adhesion molecules or production of peroxides. Lx, however, did not activate Mac in terms of production of nitric oxide or OィイD22ィエD2- with slight enhanced production of TNFα.Lx and its diol caused slight injury of HPAEC, however, when cell glutathione contents were depleted Lx exerted more potent cytotoxicity. TSO, another epoxide, also exerted cytotoxicity in CHO whereas TSO-induced cytotoxicity was attenuated in human soluble epoxide hydrolase (hsEH) cDNA transfected CHO. Since TSO-diol injured glutathione-depleted hsEH cDNA transfected CHO, glutathione was an essential substance against epoxide-diol-induced injury. Our current study suggests inflammation provoking effects of Lx and its diol and further suggests glutathione-depleted pathological state such an acute lung injury including ARDS may augment cytotoxicity of Lx and Lx-diol.