Abstract：
Motile cilia in the ependymal cells that line the brain ventricles play pivotal roles in cerebrospinal fluid (CSF) flow in well-defined directions. However, the substances and pathways which regulate their beating have not been well studied. Here, we used primary cultured cells derived from neonatal mouse brain that possess motile cilia and found that adenosine (ADO) stimulates ciliary beating by increasing the ciliary beat frequency (CBF) in a concentration-dependent manner, with the ED50 value being 5 µM. Ciliary beating stimulated by ADO was inhibited by A2B receptor (A2BR) antagonist MRS1754 without any inhibition by antagonists of other ADO receptor subtypes. The expression of A2BR on the cilia was also confirmed by immunofluorescence. The values of CBF were also increased by forskolin, which is an activator of adenylate cyclase, whereas they were not further increased by the addition of ADO. Furthermore, ciliary beating was not stimulated by ADO in the presence of a protein kinase A (PKA) inhibitors. These results altogether suggest that ADO stimulates ciliary beating through A2BR on the cilia, and activation of PKA.
摘要：
沿脑室排列的室管膜细胞中的运动性纤毛在明确定义的方向的脑脊液（CSF）流动中起关键作用。然而,调节其跳动的物质和途径尚未得到很好的研究。这里,我们使用了来自具有活动纤毛的新生小鼠大脑的原代培养细胞，发现腺苷（ADO）通过以浓度依赖性方式增加纤毛搏动频率（CBF）来刺激纤毛搏动，ED50值为5µM。ADO刺激的纤毛搏动被A2B受体（A2BR）拮抗剂MRS1754抑制，而其他ADO受体亚型的拮抗剂没有任何抑制作用。免疫荧光也证实了A2BR在纤毛上的表达。毛喉素也增加了CBF的值，它是腺苷酸环化酶的激活剂，而添加ADO并没有进一步增加。此外，在蛋白激酶A（PKA）抑制剂存在下，ADO不会刺激纤毛搏动。这些结果完全表明，ADO通过A2BR刺激纤毛跳动，和PKA的激活。
