Department of Psychiatry, Brudnick Neuropsychiatric Research Institute; Graduate School of Biomedical Sciences, Program In Neuroscience
Molecular and Cellular Neuroscience
The mammalian target of rapamycin (mTOR) is known to regulate cell proliferation and growth by controlling protein translation. Recently, it has been shown that mTOR signaling pathway is involved in long-term synaptic plasticity. However, the role of mTOR under different pain conditions is less clear. In this study, the spatiotemporal activation of mTOR that contributes to pain-related behaviors was investigated using a novel animal inflammatory pain model induced by BmK I, a sodium channel-specific modulator purified from scorpion venom. In this study, intraplantar injections of BmK I were found to induce the activation of mTOR, p70 ribosomal S6 protein kinase (p70 S6K) and eukaryotic initiation factor 4E-binding protein 1 (4E-BP1) in rat L5-L6 spinal neurons. In the spinal cord, mTOR, p70 S6K and 4E-BP1 were observed to be activated in the ipsilateral and contralateral regions, peaking at 1-2 h and recovery at 24 h post-intraplantar (i.pl.) BmK I administration. In addition, intrathecal (i.t.) injection of rapamycin - a specific inhibitor of mTOR - was observed to result in the reduction of spontaneous pain responses and the attenuation of unilateral thermal and bilateral mechanical hypersensitivity elicited by BmK I. Thus, these results indicate that the mTOR signaling pathway is mobilized in the induction and maintenance of pain-activated hypersensitivity.
BmK I, mTOR, p70S6K, 4E-BP1, Rapamycin, Pain, Mirror-image mechanical hypersensitivity
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Copyright 2013 Jiang et al.; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
DOI of Published Version
Jiang F, Pang XY, Niu QS, Hua LM, Cheng M, Ji YH. Activation of mammalian target of rapamycin mediates rat pain-related responses induced by BmK I, a sodium channel-specific modulator. Mol Pain. 2013 Oct 8;9:50. doi:10.1186/1744-8069-9-50. Link to article on publisher's site
Jiang, Feng; Pang, Xue-Yan; Niu, Qing-Shan; Hua, Li-Ming; Cheng, Ming; and Ji, Yong-Hua, "Activation of mammalian target of rapamycin mediates rat pain-related responses induced by BmK I, a sodium channel-specific modulator" (2013). University of Massachusetts Medical School Faculty Publications. 320.