Radial glial cells (RGCs) which function as neural stem cells are known to be non-excitable and their proliferation depends on the intracellular calcium (Ca²⁺) level. It has been well established that Inositol 1,4,5-trisphosphate (IP₃)-mediated Ca²⁺ release and Ca²⁺ entry through various Ca²⁺ channels are involved in the proliferation of RGCs. Furthermore, RGCs line the ventricular wall and are exposed to a shear stress due to a physical contact with the cerebrospinal fluid (CSF). However, little is known about how the Ca²⁺ entry through mechanosensitive ion channels affects the proliferation of RGCs. Hence, we hypothesized that shear stress due to a flow of CSF boosts the proliferative potential of RGCs possibly via an activation of mechanosensitive Ca²⁺ channel during the embryonic brain development. Here, we developed a new microfluidic two-dimensional culture system to establish a link between the flow shear stress and the proliferative activity of cultured RGCs. Using this microfluidic device, we successfully visualized the artificial CSF and RGCs in direct contact and found a significant enhancement of proliferative capacity of RGCs in response to increased shear stress. To determine if there are any mechanosensitive ion channels involved, a mechanical stimulation by poking was given to individual RGCs. We found that a poking on radial glial cell induced an increase in intracellular Ca²⁺ level, which disappeared under the extracellular Ca²⁺-free condition. Our results suggest that the shear stress by CSF flow possibly activates mechanosensitive Ca²⁺ channels, which gives rise to a Ca²⁺ entry which enhances the proliferative capacity of RGCs.

中文翻译：

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流剪应力可能通过激活机械敏感性钙通道来增强培养的Rad神经胶质细胞的增殖潜能。

已知作为神经干细胞的神经胶质细胞（RGC）是不可激发的，它们的增殖取决于细胞内钙（Ca ²⁺）的水平。已经公认，肌醇1,4,5-三磷酸（IP ₃）介导的Ca ²⁺释放和Ca ²⁺通过各种条目的Ca ²⁺通道涉及视网膜神经节细胞的增殖。此外，由于与脑脊髓液（CSF）物理接触，RGC排列在心室壁上并承受剪切应力。然而，关于Ca ²⁺通过机械敏感离子通道进入会影响RGC的增殖。因此，我们假设由脑脊液流动引起的切应力可能通过激活机械敏感性Ca ^2+来增强RGC的增殖潜能。胚胎脑发育过程中的通道。在这里，我们开发了一种新的微流控二维培养系统，以建立流动剪切应力与培养的RGC的增殖活性之间的联系。使用这种微流控设备，我们成功地可视化了直接接触的人工CSF和RGC，并发现RGC响应于增加的切应力的增殖能力显着增强。为了确定是否涉及任何机械敏感离子通道，对各个RGC进行了戳戳的机械刺激。我们发现在radial骨胶质细胞上戳刺会导致细胞内Ca ²⁺水平升高，而在细胞外Ca ²⁺下消失无状态。我们的结果表明，CSF流动引起的剪切应力可能激活了对机械敏感的Ca ²⁺通道，从而导致Ca ²⁺进入，从而增强了RGC的增殖能力。