Blanchard D K, Hoffman S L, Djeu J Y
Department of Medical Microbiology and Immunology, University of South Florida College of Medicine, H. Lee Moffitt Cancer Center, Tampa, USA.
J Cell Biochem. 1995 Mar;57(3):452-64. doi: 10.1002/jcb.240570311.
Lysis of human culture-derived macrophages by extracellular ATP has recently been described, and treatment of macrophages with interferon-gamma rendered those cells significantly more sensitive to lysis. In addition, cell death occurred more rapidly in interferon (IFN)-treated cells than in untreated macrophages. In an attempt to identify the mechanism by which extracellular ATP affects macrophages, as well as to explore the differences between interferon-gamma-treated and untreated macrophages, selected metabolic inhibitors were included in the lytic assays. Of the compounds tested, three antagonists of calmodulin-linked pathways (trifluoperazine, KN-62, and calmidazolium) blocked the ATP-mediated lysis of both interferon-gamma-treated and colony-stimulating factor-treated macrophages in a dose-dependent manner. Early signals of the ATP ligation of the P2Z purinoceptors of human macrophages included increases in cytosolic [Ca2+] and depolarization of the plasma membrane. However, the inclusion of calmodulin antagonists in these assays did not abrogate either effect. These results suggest that the mechanism which mediates the efflux of 51Cr-labeled proteins from ATP-lysed macrophages is distinct from calcium mobilization and membrane depolarization, and may involve the generation of secondary pores/channels in the plasma membrane via a calmodulin-linked pathway.
最近有研究报道细胞外ATP可使源自人类培养的巨噬细胞发生溶解，用γ干扰素处理巨噬细胞会使这些细胞对溶解更加敏感。此外，经干扰素（IFN）处理的细胞比未处理的巨噬细胞死亡更快。为了确定细胞外ATP影响巨噬细胞的机制，并探究经γ干扰素处理和未处理的巨噬细胞之间的差异，在溶解试验中加入了选定的代谢抑制剂。在所测试的化合物中，三种钙调蛋白相关途径的拮抗剂（三氟拉嗪、KN-62和氯米帕明）以剂量依赖的方式阻断了ATP介导的经γ干扰素处理和经集落刺激因子处理的巨噬细胞的溶解。人类巨噬细胞P2Z嘌呤受体的ATP连接早期信号包括胞质[Ca2+]增加和质膜去极化。然而，在这些试验中加入钙调蛋白拮抗剂并没有消除这两种效应。这些结果表明，介导51Cr标记蛋白从ATP溶解的巨噬细胞中流出的机制与钙动员和膜去极化不同，可能涉及通过钙调蛋白相关途径在质膜上产生次级孔道。
