Cellular permeation of large molecules mediated by TRPM8 channels.
Cellular permeation of large molecules mediated by TRPM8 channels.
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由TRPM8通道介导的大分子的细胞渗透。
DOI：
10.1016/j.neulet.2016.12.063
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发表时间：
2017-02-03
影响因子：
2.5
通讯作者：
McKemy DD
中科院分区：
文献类型：
--
作者：
McCoy DD;Palkar R;Yang Y;Ongun S;McKemy DD
虽然大多数膜通道只能通过小离子，但最近发现某些非选择性阳离子通道具有渗透大阳离子的能力。大分子渗透的机制尚不清楚，但这一特性已被药理学利用来靶向分子，如神经传导阻滞剂，以表达热门控瞬时受体电位(TRP)通道TRPV1的痛敏神经元(伤害性感受器)的特定亚群。然而，目前尚不清楚冷刺激的主要介质TRPM8是否能够介导大分子穿过细胞膜，这表明TRPM8阳性神经不能成为类似的靶点。在这里，我们证明了表达TRPM8通道的异源细胞和本地感觉神经元都允许大的荧光阳离子Po-Pro3渗透。当通道活动不敏感时，TRPM8的特异性拮抗作用可阻断Po-Pro3的内流。强大的激动剂WS-12的作用是TRPM8专一性的，TRPM8通道介导的染料摄取与TRPV1相似。最后，我们发现，与TRPV1一样，激活TRPM8通道可以作为靶向细胞内摄取细胞内不通透性钠通道阻滞剂的手段。在表达TRPM8通道的神经元细胞系中，电压门控钠电流在细胞不通透、带电的利多卡因衍生物QX-314和WS-12存在下被阻断。这些结果表明，体感色氨酸通道促进大阳离子通透性的能力也包括TRPM8，从而提示也可以通过阻断TRPM8阳性感觉神经元的传导来改变冷痛。
While most membrane channels are only capable of passing small ions, certain non-selective cation channels have been recently shown to have the capacity to permeate large cations. The mechanisms underlying large molecule permeation are unclear, but this property has been exploited pharmacologically to target molecules, such nerve conduction blockers, to specific subsets of pain-sensing neurons (nociceptors) expressing the heat-gated transient receptor potential (TRP) channel TRPV1. However, it is not clear if the principal mediator of cold stimuli TRPM8 is capable of mediating the permeation large molecules across cell membranes, suggesting that TRPM8-positive nerves cannot be similarly targeted. Here we show that both heterologous cells and native sensory neurons expressing TRPM8 channels allow the permeation of the large fluorescent cation Po-Pro3. Po-Pro3 influx is blocked by TRPM8-specific antagonism and when channel activity is desensitized. The effects of the potent agonist WS-12 are TRPM8-specific and dye uptake mediated by TRPM8 channels is similar to that observed with TRPV1. Lastly, we find that as with TRPV1, activation of TRPM8 channels can be used as a means to target intracellular uptake of cell-impermeable sodium channel blockers. In a neuronal cell line expressing TRPM8 channels, voltage-gated sodium currents are blocked in the presence of the cell-impermeable, charged lidocaine derivative QX-314 and WS-12. These results show that the ability of somatosensory TRP channels to promote the permeation of large cations also includes TRPM8, thereby suggesting that novel approaches to alter cold pain can also be employed via conduction block in TRPM8-positive sensory neurons.