Arachidonic acid can function as a signaling modulator by activating the TRPM5 cation channel in taste receptor cells
Arachidonic acid can function as a signaling modulator by activating the TRPM5 cation channel in taste receptor cells
复制标题
DOI：
10.1016/j.bbalip.2006.07.005
复制
发表时间：
2006-09-01
影响因子：
4.8
通讯作者：
Abe, Keiko
中科院分区：
文献类型：
--
作者：
Oike, Hideaki;Wakamori, Minoru;Abe, Keiko
脊椎动物的感觉细胞，如犁鼻神经元和果蝇感光细胞使用TRP通道来响应外源性刺激。在哺乳动物的味觉细胞中，苦味和甜味物质以及一些氨基酸由G蛋白偶联受体（T2 R或T1 R）接收。由于G蛋白和磷脂酶C β 2的激活，TPPM 5通道被激活。细胞内Ca 2+是已知的TRPM 5激活剂，但脂质激活剂的参与仍然没有报道。为了阐明花生四烯酸对味觉细胞中TRPM 5的影响，我们研究了参与控制细胞内游离花生四烯酸水平的一系列酶的表达谱，结果表明，在味蕾细胞亚群中，单甘油酯脂肪酶（MGL）和环氧合酶-2（考克斯-2）以及先前报道的IIA族磷脂酶A（2）（PLA（2）-IIA）表达。双标记分析显示，MGL、考克斯-2和PLA（2）-IIA在一些表达TRPM 5的细胞中共表达。然后，我们研究了花生四烯酸是否通过HEK 293细胞中的异源表达系统激活TRPM 5，并发现其激活发生在10 μ M花生四烯酸。这些结果强烈表明花生四烯酸在味觉信号通路中作为TRPN 15的调节剂的可能性。(c)2006 Elsevier B. V.保留所有权利。
Vertebrate sensory cells such as vomeronasal neurons and Drosophila photoreceptor cells use TRP channels to respond to exogenous stimuli. In mammalian taste cells, bitter and sweet substances as well as some amino acids are received by G protein-coupled receptors (T2Rs or T1Rs). As a result of activation of G protein and phospholipase C beta 2, the TPPM5 channel is activated. Intracellular Ca2+ is known to be a TRPM5 activator, but the participation of lipid activators remains unreported. To clarify the effect of arachidonic acid on TRPM5 in taste cells, we investigated the expression profile of a series of enzymes involved in controlling the intracellular free arachidonic acid level, with the result that in a subset of taste bud cells, monoglyceride lipase (MGL) and cyclooxygenase-2 (COX-2) are expressed as well as the previously reported group IIA phospholipase A(2) (PLA(2)-IIA). Double-labeling analysis revealed that MGL, COX-2 and PLA(2)-IIA are co-expressed in some cells that express TRPM5. We then investigated whether arachidonic acid activates TRPM5 via a heterologous expression system in HEK293 cells, and found that its activation occurred at 10 mu M arachidonic acid. These results strongly suggest the possibility that arachidonic acid acts as a modulator of TRPN15 in taste signaling pathways. (c) 2006 Elsevier B.V. All rights reserved.