Lipid Signaling, Lipidomics, and Vasculotoxicity Laboratory, Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Dorothy M. Davis Heartand Lung Research Institute and Division of Pharmacology, Colleges of Medicineand Pharmacy, The Ohio State University, Columbus, OH, USA.
Int J Toxicol. 2011 Dec;30(6):619-38. doi: 10.1177/1091581811422413. Epub 2011 Oct 12.
Here, we investigated thiol-redox-mediated phospholipase D (PLD) signaling as a mechanism of mercury cytotoxicity in mouse aortic endothelial cell (MAEC) in vitro model utilizing the novel lipid-soluble thiol-redox antioxidant and heavy metal chelator, N,N'-bis(2-mercaptoethyl)isophthalamide (NBMI) and the novel PLD-specific inhibitor, 5-fluoro-2-indolyl des-chlorohalopemide (FIPI). Our results demonstrated (i) mercury in the form of mercury(II) chloride, methylmercury, and thimerosal induced PLD activation in a dose- and time-dependent manner; (ii) NBMI and FIPI completely attenuated mercury- and oxidant-induced PLD activation; (iii) mercury induced upstream phosphorylation of extracellular-regulated kinase 1/2 (ERK1/2) leading to downstream threonine phosphorylation of PLD(1) which was attenuated by NBMI; (iv) mercury caused loss of intracellular glutathione which was restored by NBMI; and (v) NBMI and FIPI attenuated mercury- and oxidant-induced cytotoxicity in MAECs. For the first time, this study demonstrated that redox-dependent and PLD-mediated bioactive lipid signaling was involved in mercury-induced vascular EC cytotoxicity which was protected by NBMI and FIPI.
在这里，我们利用新型脂溶性巯基-氧化还原抗氧化剂和重金属螯合剂 N,N'-双(2-巯基乙基)异酞酰胺 (NBMI) 以及新型 PLD 特异性抑制剂 5-氟-2-吲哚基去氯卤代肽 (FIPI)，研究了巯基-氧化还原介导的磷脂酶 D (PLD) 信号转导作为体外小鼠主动脉内皮细胞 (MAEC) 中汞细胞毒性的机制。我们的结果表明：(i) 氯化汞、甲基汞和硫柳汞以汞 (II) 盐、甲基汞和硫柳汞的形式诱导 PLD 激活呈剂量和时间依赖性；(ii) NBMI 和 FIPI 完全阻断汞和氧化剂诱导的 PLD 激活；(iii) 汞诱导细胞外调节激酶 1/2 (ERK1/2) 的上游磷酸化，导致 PLD(1)的下游苏氨酸磷酸化，NBMI 可减弱该磷酸化；(iv) 汞导致细胞内谷胱甘肽减少，NBMI 可恢复该减少；(v) NBMI 和 FIPI 可减轻 MAEC 中汞和氧化剂诱导的细胞毒性。这项研究首次表明，氧化还原依赖和 PLD 介导的生物活性脂质信号参与了汞诱导的血管内皮细胞毒性，NBMI 和 FIPI 可对其进行保护。
