TMEM16A Ca2+-Activated Cl- Channel Regulates the Proliferation and Migration of Brain Capillary Endothelial Cells
TMEM16A Ca2+-Activated Cl- Channel Regulates the Proliferation and Migration of Brain Capillary Endothelial Cells
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DOI：
10.1124/mol.119.118844
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发表时间：
2020-05
影响因子：
3.6
通讯作者：
Takahisa Suzuki;Miki Yasumoto;Yoshiaki Suzuki;K. Asai;Y. Imaizumi;H. Yamamura
中科院分区：
文献类型：
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作者：
Takahisa Suzuki;Miki Yasumoto;Yoshiaki Suzuki;K. Asai;Y. Imaizumi;H. Yamamura
血脑屏障（BBB）对于维持脑内稳态至关重要。脑毛细血管内皮细胞（BCEC）构成BBB，因此需要它们的增殖和死亡之间的微妙平衡。尽管BCECs中的离子通道活性参与了血脑屏障的功能，但其潜在的分子机制仍不清楚。在本研究中，使用小鼠BCECs（mBCECs）和来自牛BCECs的细胞系t-BBEC 117检查了Ca 2+激活的Cl−（ClCa）通道的分子组分及其生理作用。表达分析显示TMEM 16 A在mBCECs和t-BBEC 117细胞中强烈表达。在t-BBEC 117细胞中，全细胞Cl−电流对ClCa通道阻断剂100 μM尼氟灭酸和10 μM T16 Ainh-A01敏感，并且也被TMEM 16 A的小干扰RNA（siRNA）敲低显著降低。重要的是，用ClCa通道阻断剂或TMEM 16 A siRNA阻断ClCa电流诱导膜超极化。此外，用TMEM 16 A siRNA处理引起静息胞质Ca 2+浓度（[Ca 2 +]cyt）增加。T16 Ainh-A01以浓度依赖性方式降低细胞活力。ClCa通道阻断剂或TMEM 16 A siRNA也减少细胞增殖和迁移。此外，ClCa通道阻滞剂减弱了跨内皮渗透性。总的来说，这些结果强烈表明TMEM 16 A有助于ClCa通道电导，并且可以调节BCEC中的静息膜电位和[Ca 2 +]cyt。我们的数据还揭示了这些BCEC如何参与BBB功能的维持，因为通道活性的变化会改变增殖和迁移。在血脑屏障（BBB）的脑毛细血管内皮细胞（BCEC）中，TMEM 16 A负责Ca 2+激活的Cl−通道，并可调节静息膜电位和胞浆Ca 2+浓度，有助于BCEC的增殖和迁移。本研究提供了有关BBB中BCEC生理功能的分子机制的新信息，以及与BBB功能障碍相关的疾病的治疗药物的新靶点。
The blood-brain barrier (BBB) is essential for the maintenance of homeostasis in the brain. Brain capillary endothelial cells (BCECs) comprise the BBB, and thus a delicate balance between their proliferation and death is required. Although the activity of ion channels in BCECs is involved in BBB functions, the underlying molecular mechanisms remain unclear. In the present study, the molecular components of Ca2+-activated Cl− (ClCa) channels and their physiological roles were examined using mouse BCECs (mBCECs) and a cell line derived from bovine BCECs, t-BBEC117. Expression analyses revealed that TMEM16A was strongly expressed in mBCECs and t-BBEC117 cells. In t-BBEC117 cells, whole-cell Cl− currents were sensitive to the ClCa channel blockers, 100 μM niflumic acid and 10 μM T16Ainh-A01, and were also reduced markedly by small-interfering RNA (siRNA) knockdown of TMEM16A. Importantly, block of ClCa currents with ClCa channel blockers or TMEM16A siRNA induced membrane hyperpolarization. Moreover, treatment with TMEM16A siRNA caused an increase in resting cytosolic Ca2+ concentration ([Ca2+]cyt). T16Ainh-A01 reduced cell viability in a concentration-dependent manner. Either ClCa channel blockers or TMEM16A siRNA also curtailed cell proliferation and migration. Furthermore, ClCa channel blockers attenuated the trans-endothelial permeability. In combination, these results strongly suggest that TMEM16A contributes to ClCa channel conductance and can regulate both the resting membrane potential and [Ca2+]cyt in BCECs. Our data also reveal how these BCECs may be involved in the maintenance of BBB functions, as both the proliferation and migration are altered following changes in channel activity. SIGNIFICANCE STATEMENT In brain capillary endothelial cells (BCECs) of the blood-brain barrier (BBB), TMEM16A is responsible for Ca2+-activated Cl− channels and can regulate both the resting membrane potential and cytosolic Ca2+ concentration, contributing to the proliferation and migration of BCECs. The present study provides novel information on the molecular mechanisms underlying the physiological functions of BCECs in the BBB and a novel target for therapeutic drugs for disorders associated with dysfunctions in the BBB.