Chloride Channel Blockers Suppress Formation of Engulfment Pseudopodia in Microglial Cells
Chloride Channel Blockers Suppress Formation of Engulfment Pseudopodia in Microglial Cells
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DOI：
10.1159/000343370
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发表时间：
2013-01-01
影响因子：
--
通讯作者：
Kerschbaum, Hubert H.
中科院分区：
文献类型：
--
作者：
Harl, Barbara;Schmoelzer, Judith;Kerschbaum, Hubert H.
背景/目的：吞噬作用依赖于目标周围吞噬伪足的形成。我们测试了在小胶质细胞，单核细胞衍生的细胞在大脑中，无论是膨胀激活的Cl-电流（I-Cl，I-膨胀），所需的全球细胞体积（CV）的调节，也有助于局部扩张和收缩的吞噬伪足。研究方法：我们使用扫描电子显微镜（SEM）和共聚焦激光扫描显微镜（CLSM）来可视化和量化小胶质细胞对聚苯乙烯微珠（MB）的摄取。流式细胞仪测定细胞体积，全细胞膜片钳法测定I-Cl、I-swell。结果如下：我们发现，暴露的小胶质细胞BV-2细胞的MB在无Cl-细胞外溶液衰减MB的摄取和Cl-通道阻断剂DIOA，氟芬那酸，NPPB和DCPIB抑制MB的BV-2细胞和原代小胶质细胞的摄取。在存在Cl-通道阻断剂的情况下，暴露于MB的小胶质细胞未能延长吞噬伪足。我们观察到，含有至少三个MB的细胞显示与没有MB的细胞相比，I-Cl，I-溶胀的电流密度增加约两倍。在暴露于MB之前刺激全局CV调节的渗透挑战调节吞噬作用。细胞在低渗或高渗培养基中预处理12-16小时导致MB摄取减少。结论：这些结果表明，I-Cl，I-swell有助于吞噬伪足的形成，并参与小胶质细胞的吞噬和颗粒摄取。版权所有（C）2013 S. Karger AG，巴塞尔
Background/Aims: Phagocytosis depends on the formation of engulfment pseudopodia surrounding the target. We tested in microglia, monocyte-derived cells in the brain, whether a swelling-activated Cl--current (I-Cl,I- swell), required for global cell volume (CV) regulation, also contributes to local expansion and retraction of engulfment pseudopodia. Methods: We used scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) to visualize and quantify the uptake of polystyrene microbeads (MBs) by microglial cells. Flow cytometry was used for cell volume measurments and I-Cl,I- swell was measured by whole-cell patch clamp. Results: We found that exposure of microglial BV-2 cells to MBs in Cl--free extracellular solution attenuated MB uptake and that the Cl--channel blockers DIOA, flufenamic acid, NPPB and DCPIB suppressed the uptake of MBs in BV-2 cells and in primary microglial cells. Microglial cells exposed to MBs in the presence of Cl- channel blockers failed to extend engulfment pseudopodia. We observed that cells containing at least three MBs revealed an about twofold increase in current density of I-Cl,I- swell compared to cells without MB. Osmotic challenges to stimulate global CV regulation before exposure to MBs modulated phagocytosis. Pre-conditioning of cells in hypo- or hypertonic medium for 12-16 hours caused a decrease in MB uptake. Conclusion: These findings indicate that I-Cl,I- swell contributes to formation of engulfment pseudopodia and participates in engulfment and particle uptake in microglial cells. Copyright (C) 2013 S. Karger AG, Basel