Department of Neurosurgery, the 2nd Affiliated Hospital, Harbin Medical University, Harbin 150086, P.R. China.
Oncol Rep. 2013 Dec;30(6):2852-8. doi: 10.3892/or.2013.2777. Epub 2013 Oct 2.
Recent studies have implicated the acid-sensing ion channel 1 (ASIC1), a proton-gated cation channel that belongs to the epithelial sodium channel (ENaC)/Degenerin family, plays an important role in glioma cell migration. Among the ASIC subunits, only ASIC1a has been found be calcium permeable. However, it has not been determined whether Ca2+/calmodulin-dependent protein kinase II (CaMKII) regulates ASIC1 in glioblastoma multiforme (GBM). Herein, we report that ASIC1 and CaMKII assemble to form a functional complex at the plasma membrane of GBM cells. We found that migration ability was significantly attenuated in GBM cells that were pre-treated with autocamtide-2-related inhibitory peptide (AIP), a CaMKII-specific inhibitor, or psalmotoxin 1 (PcTX-1), a selective ASIC1 blocker. Furthermore, the inhibitory effect of AIP or PcTX-1 on migration was diminished when ASIC1 was knocked down in GBM cells; when ASIC1 knockdown GBM cells were concurrently treated with these two inhibitors, cell migration was slightly but significantly decreased. Using whole-cell patch-clamp recordings, we detected an amiloride-sensitive current in GBM cells, and this current was significantly inhibited by both PcTX-1 and AIP. Moreover, the magnitude of this current was dramatically decreased when ASIC1 was knocked down in GBM cells. The addition of AIP failed to further decrease the amplitude of this current. Taken together, these data suggest that ASIC1 and CaMKII form a functional complex in GBM cells. Furthermore, it can be concluded that CaMKII regulates the activity of ASIC1, which is associated with the ability of GBM cells to migrate.
近期研究表明，酸感应离子通道 1（ASIC1）在神经胶质瘤细胞迁移中发挥重要作用。ASIC1 是一种质子门控阳离子通道，属于上皮钠通道（ENaC）/退行离子通道家族。在 ASIC 亚基中，只有 ASIC1a 被发现具有钙通透性。然而，尚未确定 Ca2+/钙调蛋白依赖性蛋白激酶 II（CaMKII）是否调节多形性胶质母细胞瘤（GBM）中的 ASIC1。在此，我们报告 ASIC1 和 CaMKII 在 GBM 细胞的质膜上组装形成功能性复合物。我们发现，在用 CaMKII 特异性抑制剂 autocamtide-2 相关抑制肽（AIP）或选择性 ASIC1 阻断剂 psalmotoxin 1（PcTX-1）预处理的 GBM 细胞中，迁移能力显著减弱。此外，当在 GBM 细胞中敲低 ASIC1 时，AIP 或 PcTX-1 对迁移的抑制作用减弱；当 ASIC1 敲低的 GBM 细胞同时用这两种抑制剂处理时，细胞迁移略有但显著减少。使用全细胞膜片钳记录，我们在 GBM 细胞中检测到阿米洛利敏感电流，该电流被 PcTX-1 和 AIP 均显著抑制。此外，当在 GBM 细胞中敲低 ASIC1 时，该电流的幅度明显降低。向 AIP 中添加未能进一步降低该电流的幅度。总之，这些数据表明 ASIC1 和 CaMKII 在 GBM 细胞中形成功能性复合物。此外，可以得出结论，CaMKII 调节 ASIC1 的活性，这与 GBM 细胞迁移能力有关。
