Flow Shear Stress Enhances the Proliferative Potential of Cultured Radial Glial Cells Possibly Via an Activation of Mechanosensitive Calcium Channel.
- Author:
Min Gu PARK
1
;
Heeyeong JANG
;
Sang Hoon LEE
;
C Justin LEE
Author Information
- Publication Type:Original Article
- Keywords: Radial glial cell; Shear stress; Mechanosensitive ion channel
- MeSH: Brain; Calcium Channels*; Calcium*; Cerebrospinal Fluid; Ependymoglial Cells*; Inositol 1,4,5-Trisphosphate; Ion Channels; Lab-On-A-Chip Devices; Microfluidics; Neural Stem Cells
- From:Experimental Neurobiology 2017;26(2):71-81
- CountryRepublic of Korea
- Language:English
- Abstract: 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.
