Caged vanilloid ligands for activation of TRPV1 receptors by 1-and 2-photon excitation
Caged vanilloid ligands for activation of TRPV1 receptors by 1-and 2-photon excitation
复制标题
DOI：
10.1021/bi052082f
复制
发表时间：
2006-04-18
期刊：
影响因子：
2.9
通讯作者：
Kao, JPY
中科院分区：
文献类型：
--
作者：
Zhao, J;Gover, TD;Kao, JPY
周围神经系统中的伤害性神经元检测有害刺激并将信息报告给中枢神经系统。大多数伤害性神经元表达香草酸受体 TRPV 1，这是一种由香草酸配体（例如辣椒素（辣椒的辛辣精华））门控的非选择性阳离子通道。在这里，我们报告了两种笼状香草酸的合成和生物应用：生物惰性前体，在光解时释放生物活性香草酸配体。两种笼状香草醛 Nb-VNA 和 Nv-VNA 分别以 0. 13 和 0.04 1 的量子效率进行光释放。在闪光光解条件下，Nb-VNA和Nv-VNA的光释放分别在约40μs和约125μs内完成95％。通过紫外光 (360 nm) 的 1 光子激发或红光 (720 nm) 的 2 光子激发，笼状香草素可以原位光释放，激活伤害性神经元上的 TRPV1 受体。随后细胞内游离 Ca2+ 浓度 ([Ca2+](i)) 的增加可以通过负载荧光 Ca2+ 指示剂 Fluo-3 的神经元的激光扫描共聚焦成像来可视化。 TRPV1 受体激活的模拟结果，因为该反应被辣椒西平（一种选择性 TRPV1 拮抗剂）阻断。在无 Ca2+ 的细胞外培养基中，光释放的香草酸仍然可以升高 [Ca2+](i)，这表明 TRPV1 受体也驻留在神经元的内膜上，并且可以介导细胞内储存的 Ca2+ 释放。值得注意的是，全细胞电压钳测量表明香草醛的闪光光释放可以激活 TRPV1 通道
Nociceptive neurons in the peripheral nervous system detect noxious stimuli and report the information to the central nervous system. Most nociceptive neurons express the vanilloid receptor, TRPV 1, a nonselective cation channel gated by vanilloid ligands such as capsaicin, the pungent essence of chili peppers. Here, we report the synthesis and biological application of two caged vanilloids: biologically inert precursors that, when photolyzed, release bioactive vanilloid ligands. The two caged vanilloids, Nb-VNA and Nv-VNA, are photoreleased with quantum efficiency of 0. 13 and 0.04 1, respectively. Under flash photolysis conditions, photorelease of Nb-VNA and Nv-VNA is 95% complete in similar to 40 mu s and similar to 125 mu s, respectively. Through 1 -photon excitation with ultraviolet light (360 nm), or 2-photon excitation with red light (720 nm), the caged vanilloids can be photoreleased in situ to activate TRPV1 receptors on nociceptive neurons. The consequent increase in intracellular free Ca2+ concentration ([Ca2+](i)) can be Visualized by laser-scanning confocal imaging of neurons loaded with the fluorescent Ca2+ indicator, fluo-3. Simulation results from TRPV1 receptor activation, because the response is blocked by capsazepine, a selective TRPV1 antagonist. In Ca2+-free extracellular medium, photoreleased vanilloid can still elevate [Ca2+](i), which suggests that TRPV1 receptors also reside on endomembranes in neurons and can mediate Ca2+ release from intracellular stores. Notably, whole-cell voltage clamp measurements showed that flash photorelease of vanilloid can activate TRPV1 channels in