Pulmonary Research Group, Department of Medicine, University of Alberta, 550 HMRC, Edmonton, AB, Canada T6G 2S2.
Biomed Res Int. 2014;2014:803257. doi: 10.1155/2014/803257. Epub 2014 Jul 6.
Eosinophils circulate in the blood and are recruited in tissues during allergic inflammation. Gap junctions mediate direct communication between adjacent cells and may represent a new way of communication between immune cells distinct from communication through cytokines and chemokines. We characterized the expression of connexin (Cx)43 by eosinophils isolated from atopic individuals using RT-PCR, Western blotting, and confocal microscopy and studied the biological functions of gap junctions on eosinophils. The formation of functional gap junctions was evaluated measuring dye transfer using flow cytometry. The role of gap junctions on eosinophil transendothelial migration was studied using the inhibitor 18-a-glycyrrhetinic acid. Peripheral blood eosinophils express Cx43 mRNA and protein. Cx43 is localized not only in the cytoplasm but also on the plasma membrane. The membrane impermeable dye BCECF transferred from eosinophils to epithelial or endothelial cells following coculture in a dose and time dependent fashion. The gap junction inhibitors 18-a-glycyrrhetinic acid and octanol did not have a significant effect on dye transfer but reduced dye exit from eosinophils. The gap junction inhibitor 18-a-glycyrrhetinic acid inhibited eosinophil transendothelial migration in a dose dependent manner. Thus, eosinophils from atopic individuals express Cx43 constitutively and Cx43 may play an important role in eosinophil transendothelial migration and function in sites of inflammation.
嗜酸性粒细胞在血液中循环，并在过敏炎症期间募集到组织中。缝隙连接介导相邻细胞之间的直接通讯，可能代表免疫细胞之间不同于细胞因子和趋化因子通讯的一种新的通讯方式。我们使用 RT-PCR、Western 印迹和共聚焦显微镜对来自特应性个体的嗜酸性粒细胞中连接蛋白 (Cx)43 的表达进行了表征，并研究了缝隙连接对嗜酸性粒细胞的生物学功能。通过流式细胞术测量染料转移来评估功能性缝隙连接的形成。使用抑制剂 18-a-甘草次酸研究了缝隙连接对嗜酸性粒细胞跨内皮迁移的作用。外周血嗜酸性粒细胞表达 Cx43 mRNA 和蛋白。Cx43 不仅定位于细胞质，还定位于质膜上。在共培养中，膜不可渗透的染料 BCECF 以剂量和时间依赖的方式从嗜酸性粒细胞转移到上皮或内皮细胞。缝隙连接抑制剂 18-a-甘草次酸和辛醇对染料转移没有显著影响，但减少了染料从嗜酸性粒细胞中的逸出。缝隙连接抑制剂 18-a-甘草次酸以剂量依赖的方式抑制嗜酸性粒细胞的跨内皮迁移。因此，特应性个体的嗜酸性粒细胞持续表达 Cx43，Cx43 可能在炎症部位的嗜酸性粒细胞跨内皮迁移和功能中发挥重要作用。
