Institute of Anatomy and Cell Biology and Institute for Clinical Immunology and Transfusion Medicine, Justus-Liebig-University, Giessen D-35385, Germany.
Proc Natl Acad Sci U S A. 2011 Jun 7;108(23):9478-83. doi: 10.1073/pnas.1019418108. Epub 2011 May 23.
In the epithelium of the lower airways, a cell type of unknown function has been termed "brush cell" because of a distinctive ultrastructural feature, an apical tuft of microvilli. Morphologically similar cells in the nose have been identified as solitary chemosensory cells responding to taste stimuli and triggering trigeminal reflexes. Here we show that brush cells of the mouse trachea express the receptors (Tas2R105, Tas2R108), the downstream signaling molecules (α-gustducin, phospholipase C(β2)) of bitter taste transduction, the synthesis and packaging machinery for acetylcholine, and are addressed by vagal sensory nerve fibers carrying nicotinic acetylcholine receptors. Tracheal application of an nAChR agonist caused a reduction in breathing frequency. Similarly, cycloheximide, a Tas2R108 agonist, evoked a drop in respiratory rate, being sensitive to nicotinic receptor blockade and epithelium removal. This identifies brush cells as cholinergic sensors of the chemical composition of the lower airway luminal microenvironment that are directly linked to the regulation of respiration.
在下呼吸道的上皮细胞中，有一种功能未知的细胞类型被称为“刷状细胞”，因为其具有独特的超微结构特征，即顶端微绒毛的簇状。在鼻子中形态相似的细胞已被鉴定为对味觉刺激有反应并引发三叉神经反射的单个化学感觉细胞。在这里，我们表明，小鼠气管的刷状细胞表达味觉转导的受体（Tas2R105、Tas2R108）、下游信号分子（α-味觉素、磷脂酶 Cβ2）、乙酰胆碱的合成和包装机制，并且被携带烟碱型乙酰胆碱受体的迷走感觉神经纤维所支配。气管应用烟碱型乙酰胆碱受体激动剂可引起呼吸频率降低。同样，Tas2R108 激动剂环已酰亚胺也可引起呼吸频率下降，对烟碱受体阻断和上皮细胞去除敏感。这表明刷状细胞是下呼吸道腔微环境化学成分的胆碱能传感器，与呼吸调节直接相关。
