Morphologic characterization of rat taste receptor cells that express components of the phospholipase C signaling pathway
Morphologic characterization of rat taste receptor cells that express components of the phospholipase C signaling pathway
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DOI：
10.1002/cne.10963
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发表时间：
2004-01-12
影响因子：
2.5
通讯作者：
Kinnamon, JC
中科院分区：
文献类型：
--
作者：
Clapp, TR;Yang, RB;Kinnamon, JC
大鼠味蕾含有三种形态上不同的细胞类型，它们是味觉转导的候选者。然而，这些细胞的生理作用尚不清楚。肌醇1，4，5-三磷酸（IP 3）已被牵连作为一个重要的第二信使在苦，甜，和鲜味的味道转导。以前，我们确定III型IP 3受体（IP（3）R3）为主要亚型。味觉感受器细胞。此外，最近的一项研究表明，磷脂酶C β（2）（PLC β（2））对于苦，甜和鲜味刺激的转导至关重要。IP（3）R3和PLC β（2）在相同的细胞亚群中表达。为了鉴定表达PLC信号转导相关蛋白的味觉细胞类型，我们使用3，3 '-二氨基联苯胺四盐酸盐免疫电镜和荧光显微镜来鉴定具有IP（3）R3的细胞。共聚焦显微镜用于比较IP（3）R3或PLC β（2）与一些已知细胞类型标记物如5-羟色胺、蛋白基因调节产物9.5和神经细胞粘附分子的免疫反应性。在这里，我们表明，一个大的子集的II型细胞和一个小的子集的III型细胞显示IP（3）R3免疫反应在其细胞质。这些数据表明，II型细胞是苦，甜，和鲜味的味道转导的主要换能器。然而，我们没有观察到II型味觉细胞和神经纤维之间的突触。有趣的是，我们观察到表面下池的滑面内质网之间的质膜的II型味觉细胞和神经过程的密切appositions。我们推测，一些II型细胞可能沟通的神经系统通过亚表面池的滑面内质网代替传统的突触。(C)2003 Wiley-Liss，Inc.
Rat taste buds contain three morphologically distinct cell types that are candidates for taste transduction. The physiologic roles of these cells are, however, not clear. Inositol 1,4,5-triphosphate (IP3) has been implicated as an important second messenger in bitter, sweet, and umami taste transductions. Previously, we identified the type III IP3 receptor (IP(3)R3) as the dominant isoform. in taste receptor cells. In addition, a recent study showed that phospholipase Cbeta(2) (PLCbeta(2)) is essential for the transduction of bitter, sweet, and umami stimuli. IP(3)R3 and PLCbeta(2) are expressed in the same subset of cells. To identify the taste cell types that express proteins involved in PLC signal transduction, we used 3,3'diaminobenzidine tetrahydrochloride immunoelectron microscopy and fluorescence microscopy to identify cells with IP(3)R3. Confocal microscopy was used to compare IP(3)R3 or PLCbeta(2) immunoreactivity with that of some known cell type markers such as serotonin, protein gene-regulated product 9.5, and neural cell adhesion molecule. Here we show that a large subset of type II cells and a small subset of type III cells display IP(3)R3 immunoreactivity within their cytoplasm. These data suggest that type II cells are the principal transducers of bitter, sweet, and umami taste transduction. However, we did not observe synapses between type II taste cells and nerve fibers. Interestingly, we observed subsurface cisternae of smooth endoplasmic reticulum at the close appositions between the plasma membrane of type II taste cells and nerve processes. We speculate that some type II cells may communicate to the nervous system via subsurface cisternae of smooth endoplasmic reticulum in lieu of conventional synapses. (C) 2003 Wiley-Liss, Inc.