The Tunicate Metabolite 2‑(3,5-Diiodo-4-methoxyphenyl)ethan-1-amine Targets Ion Channels of Vertebrate Sensory Neurons
journal contributionposted on 23.08.2021, 15:03 by Noemi D. Paguigan, Yannan Yan, Manju Karthikeyan, Kevin Chase, Jackson Carter, Lee S. Leavitt, Albebson L. Lim, Zhenjian Lin, Tosifa Memon, Sean Christensen, Bo H. Bentzen, Nicole Schmitt, Christopher A. Reilly, Russell W. Teichert, Shrinivasan Raghuraman, Baldomero M. Olivera, Eric W. Schmidt
Marine tunicates produce defensive amino-acid-derived metabolites, including 2-(3,5-diiodo-4-methoxyphenyl)ethan-1-amine (DIMTA), but their mechanisms of action are rarely known. Using an assay-guided approach, we found that out of the many different sensory cells in the mouse dorsal root ganglion (DRG), DIMTA selectively affected low-threshold cold thermosensors. Whole-cell electrophysiology experiments using DRG cells, channels expressed in Xenopus oocytes, and human cell lines revealed that DIMTA blocks several potassium channels, reducing the magnitude of the afterhyperpolarization and increasing the baseline intracellular calcium concentration [Ca2+]i of low-threshold cold thermosensors. When injected into mice, DIMTA increased the threshold of cold sensation by >3 °C. DIMTA may thus serve as a lead in the further design of compounds that inhibit problems in the cold-sensory system, such as cold allodynia and other neuropathic pain conditions.
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assay-guided approachWhole-cell electrophysiology experi...DRG cellsDIMTA blocks-4-methoxyphenylIon Channelscell linescold-sensory systembaseline intracellular calcium conc...Vertebrate Sensory Neurons Marine t...potassium channelsmouse dorsal root ganglionneuropathic pain conditionsamino-acid-derived metaboliteslow-thresholdXenopus oocytesthermosensor