Hydrogen peroxide and ADP-ribose induce TRPM2-mediated calcium influx and cation currents in microglia
Hydrogen peroxide and ADP-ribose induce TRPM2-mediated calcium influx and cation currents in microglia
复制标题
DOI：
10.1152/ajpcell.00331.2003
复制
发表时间：
2004-01-01
影响因子：
5.5
通讯作者：
Harteneck, C
中科院分区：
文献类型：
--
作者：
Kraft, R;Grimm, C;Harteneck, C
小胶质细胞是中枢神经系统中的宿主巨噬细胞，并对脑损伤和各种神经系统疾病作出反应。在这个过程中，小胶质细胞经历了从静息细胞到完全激活的吞噬组织巨噬细胞的多种形态和功能变化。在培养中，细菌脂多糖（LPS）是诱导这种激活的常用工具。应用钙离子成像和膜片钳技术，研究了巨噬细胞释放的过氧化氢（H_2O_2）对培养的大鼠小胶质细胞内钙离子浓度和离子电流的影响。应用0.1 - 5 mM H2 O2几分钟诱导未处理细胞的小反应，但LPS处理的细胞中的大的钙内流和阳离子电流。在未经处理和LPS处理的小胶质细胞，ADPribose（ADPR）通过贴片移液管内部灌注引起大的阳离子电流。两种刺激，H2 O2和ADPR，已被报道激活最近克隆的非选择性阳离子通道TRPM 2。从培养的大鼠神经胶质细胞和神经元细胞的RT-PCR分析证实了TRPM 2在大鼠小胶质细胞中的强表达，但在星形胶质细胞和小脑颗粒细胞中没有。小鼠脑的原位杂交显示TRPM 2的分布，这与小胶质细胞中的表达是相容的。总之，我们在这里描述了一种新的钙离子内流途径在小胶质细胞耦合过氧化氢和ADPR，并提供证据表明，这一途径涉及TRPM 2。在LPS刺激的细胞中对H2 O2的敏感性增加表明TRPM 2在活化的小胶质细胞的钙信号传导中的作用。
Microglial cells are the host macrophages in the central nervous system and respond to brain injury and various neurological diseases. In this process, microglial cells undergo multiple morphological and functional changes from the resting cell toward a fully activated, phagocyting tissue macrophage. In culture, bacterial lipopolysaccharide (LPS) is a frequently used tool to induce this activation. By using calcium-imaging and patch-clamp techniques, we investigated the effect of hydrogen peroxide (H2O2), which is released by macrophagic cells themselves, on the intracellular calcium concentration and ion currents in cultured rat microglia. Application of 0.1 - 5 mM H2O2 for several minutes induced small responses in untreated cells but a large calcium influx and cation current in LPS-treated cells. In both untreated and LPS-treated microglia, internal perfusion of ADPribose (ADPR) via the patch pipette elicited large cation currents. Both stimuli, H2O2 and ADPR, have been reported to activate the recently cloned nonselective cation channel TRPM2. RT-PCR analysis from cultured rat glial and neuronal cells confirmed a strong expression of TRPM2 in rat microglia but not in astrocytes and cerebellar granule cells. In situ hybridizations from mouse brain showed a distribution of TRPM2, which is compatible with the expression in microglial cells. In conclusion, we describe here a novel calcium influx pathway in microglia coupled to hydrogen peroxide and ADPR and provide evidence that this pathway involves TRPM2. The increased sensitivity to H2O2 in LPS-stimulated cells suggests a role for TRPM2 in the calcium signaling of activated microglia.