Cotrina M L, Lin J H, Nedergaard M
Departments of Cell Biology and Anatomy, Pathology, and Neurosurgery, New York Medical College, Valhalla, New York 10595, USA.
J Neurosci. 1998 Nov 1;18(21):8794-804. doi: 10.1523/JNEUROSCI.18-21-08794.1998.
We have studied the role of actin fiber assembly on calcium signaling in astrocytes. We found that (1) after astrocytes have been placed in culture, it takes several hours for organization of the definitive actin cytoskeleton. Actin organization and the number of cells engaged in calcium signaling increased in parallel. (2) Disruption of the actin cytoskeleton attenuated the calcium wave propagation; cytochalasin D treatment reduced the number of astrocytes engaged in calcium signaling. (3) Propagation of calcium waves depends on cytoskeletal function; inhibition of myosin light chain kinase suppressed wave activity. (4) Astrocytic calcium signaling is mediated by release of ATP and purinergic receptor stimulation, because agents that interfere with this cascade attenuated or reduced calcium signaling. Because purinergic receptors are fully functional shortly after plating and not affected by cytochalasin D, these observations indicate that cytoskeleton organization is a prerequisite for interastrocytic calcium signaling mediated by release of ATP.
我们研究了肌动蛋白纤维组装在星形胶质细胞钙信号传导中的作用。我们发现：（1）星形胶质细胞接种于培养物后，需要数小时才能形成确定的肌动蛋白细胞骨架。肌动蛋白组织和参与钙信号传导的细胞数量呈平行增加。（2）肌动蛋白细胞骨架的破坏减弱了钙波传播；细胞松弛素D处理减少了参与钙信号传导的星形胶质细胞数量。（3）钙波的传播依赖于细胞骨架功能；肌球蛋白轻链激酶的抑制抑制了波活动。（4）星形胶质细胞的钙信号传导由ATP释放和嘌呤能受体刺激介导，因为干扰该级联反应的试剂会减弱或减少钙信号传导。由于嘌呤能受体在接种后不久就完全发挥功能且不受细胞松弛素D影响，这些观察结果表明细胞骨架组织是由ATP释放介导的星形胶质细胞间钙信号传导的先决条件。
