Dynamic regulation of the P2X4 receptor in alveolar macrophages by phagocytosis and classical activation
Dynamic regulation of the P2X4 receptor in alveolar macrophages by phagocytosis and classical activation
复制标题
通过吞噬作用和经典激活对肺泡巨噬细胞中 P2X4 受体的动态调节
DOI：
10.1002/eji.200838818
复制
发表时间：
2009
影响因子：
5.4
通讯作者：
A. Surprenant
中科院分区：
文献类型：
--
作者：
L. Stokes;A. Surprenant
巨噬细胞和小胶质细胞中的ATP门控P2 X4受体（P2 X4 R）通过目前尚未确定的机制与神经性和炎性疼痛有关。P2 X4 R主要存在于细胞内溶酶体区室中，但可通过诱导内溶酶体分泌的程序快速运输至表面膜。我们通过Western印迹和生物素化试验研究了人和大鼠肺泡巨噬细胞对酵母聚糖和调理酵母聚糖生物颗粒的吞噬作用以及经典和替代巨噬细胞活化的反应，并通过全细胞膜片钳试验研究了总和表面膜P2 X4 R蛋白表达。未受刺激的巨噬细胞表现出高的总蛋白表达，但非常低的功能表达。吞噬作用迅速（4小时内）使功能性P2 X4 R表达增加2 - 7倍，与氯喹（一种已知诱导溶酶体分泌的药物）一样。相比之下，用IFN-γ和TNF-α或IFN-γ和LPS经典活化巨噬细胞48 h使表面和功能性P2 X4 R表达降低3倍，而不改变总P2 X4 R蛋白水平。用IL-4或IL-13替代活化不会改变P2 X4 R的总表达、表面表达或功能表达。这是第一次研究生理刺激对巨噬细胞中P2 X4 R的调节，并呈现了P2 X4 R响应于初始吞噬刺激而发挥功能，但在经典巨噬细胞激活的持续激活过程中恢复到非功能状态的图片。
ATP‐gated P2X4 receptors (P2X4R) in macrophages and microglia have been implicated in neuropathic and inflammatory pain by currently unidentified mechanisms. P2X4R are found predominantly in intracellular lysosomal compartments but can be rapidly trafficked to the surface membrane by procedures that induce endolysosomal secretion. We studied total and surface membrane P2X4R protein expression by Western blot and biotinylation assays and functional expression by whole‐cell patch clamp assays in human and rat alveolar macrophages in response to phagocytosis of zymosan and opsonized zymosan bioparticles and to classical and alternative macrophage activation. Unstimulated macrophages showed high total protein expression but very low functional expression. Phagocytosis rapidly (within 4 h) increased functional P2X4R expression by 2‐ to 7‐fold as did chloroquine, an agent known to induce lysosomal secretion. In contrast, classical activation of macrophage for 48 h with IFN‐γ and TNF‐α or IFN‐γ and LPS reduced surface and functional P2X4R expression by 3‐fold without altering total P2X4R protein levels. Alternative activation with IL‐4 or IL‐13 did not alter total, surface or functional expression of P2X4R. This is the first study of the regulation of P2X4R in macrophages by physiological stimuli and presents a picture whereby P2X4R become functional in response to initial phagocytic stimuli but return to a non‐functional state during sustained activation by classical macrophage activation.