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Kim IY, Park CS, Seo KJ, Lee JY, Yune TY. TRPM7 Mediates Neuropathic Pain by Activating mTOR Signaling in Astrocytes after Spinal Cord Injury in Rats. Mol Neurobiol 2024; 61:5265-5281. [PMID: 38180616 DOI: 10.1007/s12035-023-03888-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 12/14/2023] [Indexed: 01/06/2024]
Abstract
In this study, we investigated whether transient receptor melastatin 7 (TRPM7), known as a non-selective cation channel, inhibits neuropathic pain after spinal cord injury (SCI) and how TRPM7 regulates neuropathic pain. Neuropathic pain was developed 4 weeks after moderate contusive SCI and TRPM7 was markedly upregulated in astrocytes in the lamina I and II of L4-L5 dorsal horn. In addition, both mechanical allodynia and thermal hyperalgesia were significantly alleviated by a TRPM7 inhibitor, carvacrol. In particular, carvacrol treatment inhibited mechanistic target of rapamycin (mTOR) signaling, which was activated in astrocytes. When rats were treated with rapamycin, an inhibitor of mTOR signaling, neuropathic pain was significantly inhibited. Furthermore, blocking TRPM7 and mTOR signaling by carvacrol and rapamycin inhibited astrocyte activation in lamina I and II of dorsal spinal cord and reduced the level of p-JNK and p-c-Jun, which are known to be activated in astrocytes. Finally, inhibiting TRPM7/mTOR signaling also downregulated the production of pain-related factors such as tumor necrosis factor-α, interleukin-6, interleukin-1β, chemokine (C-C motif) ligand (CCL) 2, CCL-3, CCL-4, CCL-20, chemokine C-X-C motif ligand 1, and matrix metalloproteinase 9 which are known to be involved in the induction and/or maintenance of neuropathic pain after SCI. These results suggest an important role of TRPM7-mediated mTOR signaling in astrocyte activation and thereby induction and/or maintenance of neuropathic pain after SCI.
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Affiliation(s)
- In Yi Kim
- Age-Related and Brain Diseases Research Center, Kyung Hee University, Medical Building 10th Floor, Dongdaemun-Gu, Hoegi-Dong 1, Seoul, 02447, Republic of Korea
- Department of Biomedical Science, Kyung Hee University, Seoul, 02447, Republic of Korea
- Biomedical Science Institute, Kyung Hee University, Seoul, 02447, Republic of Korea
| | - Chan Sol Park
- Age-Related and Brain Diseases Research Center, Kyung Hee University, Medical Building 10th Floor, Dongdaemun-Gu, Hoegi-Dong 1, Seoul, 02447, Republic of Korea
- Department of Biomedical Science, Kyung Hee University, Seoul, 02447, Republic of Korea
| | - Kyung Jin Seo
- Age-Related and Brain Diseases Research Center, Kyung Hee University, Medical Building 10th Floor, Dongdaemun-Gu, Hoegi-Dong 1, Seoul, 02447, Republic of Korea
- Department of Biomedical Science, Kyung Hee University, Seoul, 02447, Republic of Korea
- Biomedical Science Institute, Kyung Hee University, Seoul, 02447, Republic of Korea
| | - Jee Youn Lee
- Age-Related and Brain Diseases Research Center, Kyung Hee University, Medical Building 10th Floor, Dongdaemun-Gu, Hoegi-Dong 1, Seoul, 02447, Republic of Korea.
| | - Tae Young Yune
- Age-Related and Brain Diseases Research Center, Kyung Hee University, Medical Building 10th Floor, Dongdaemun-Gu, Hoegi-Dong 1, Seoul, 02447, Republic of Korea.
- Department of Biomedical Science, Kyung Hee University, Seoul, 02447, Republic of Korea.
- Biomedical Science Institute, Kyung Hee University, Seoul, 02447, Republic of Korea.
- Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul, 02447, Republic of Korea.
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Alsalem M, Ellaithy A, Bloukh S, Haddad M, Saleh T. Targeting therapy-induced senescence as a novel strategy to combat chemotherapy-induced peripheral neuropathy. Support Care Cancer 2024; 32:85. [PMID: 38177894 DOI: 10.1007/s00520-023-08287-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 12/20/2023] [Indexed: 01/06/2024]
Abstract
Chemotherapy-induced peripheral neuropathy (CIPN) is a treatment-limiting adverse effect of anticancer therapy that complicates the lifestyle of many cancer survivors. There is currently no gold-standard for the assessment or management of CIPN. Subsequently, understanding the underlying mechanisms that lead to the development of CIPN is essential for finding better pharmacological therapy. Therapy-induced senescence (TIS) is a form of senescence that is triggered in malignant and non-malignant cells in response to the exposure to chemotherapy. Recent evidence has also suggested that TIS develops in the dorsal root ganglia of rodent models of CIPN. Interestingly, several components of the senescent phenotype are commensurate with the currently established primary processes implicated in the pathogenesis of CIPN including mitochondrial dysfunction, oxidative stress, and neuroinflammation. In this article, we review the literature that supports the hypothesis that TIS could serve as a holistic mechanism leading to CIPN, and we propose the potential for investigating senotherapeutics as means to mitigate CIPN in cancer survivors.
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Affiliation(s)
- Mohammad Alsalem
- Department of Anatomy and Histology, School of Medicine, The University of Jordan, Amman, 11942, Jordan
| | - Amr Ellaithy
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Sarah Bloukh
- Department of Anatomy and Histology, School of Medicine, The University of Jordan, Amman, 11942, Jordan
| | - Mansour Haddad
- Department of Clinical Pharmacy and Pharmacy Practice, Faculty of Pharmacy, Yarmouk University, Irbid, 21163, Jordan
| | - Tareq Saleh
- Department of Pharmacology and Public Health, Faculty of Medicine, The Hashemite University, Zarqa, 13133, Jordan.
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3
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Du Y, Cai X. Therapeutic potential of natural compounds from herbs and nutraceuticals in spinal cord injury: Regulation of the mTOR signaling pathway. Biomed Pharmacother 2023; 163:114905. [PMID: 37207430 DOI: 10.1016/j.biopha.2023.114905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 05/13/2023] [Accepted: 05/16/2023] [Indexed: 05/21/2023] Open
Abstract
Spinal cord injury (SCI) is a disease in which the spinal cord is subjected to various external forces that cause it to burst, shift, or, in severe cases, injure the spinal tissue, resulting in nerve injury. SCI includes not only acute primary injury but also delayed and persistent spinal tissue injury (i.e., secondary injury). The pathological changes post-SCI are complex, and effective clinical treatment strategies are lacking. The mammalian target of rapamycin (mTOR) coordinates the growth and metabolism of eukaryotic cells in response to various nutrients and growth factors. The mTOR signaling pathway has multiple roles in the pathogenesis of SCI. There is evidence for the beneficial effects of natural compounds and nutraceuticals that regulate the mTOR signaling pathways in a variety of diseases. Therefore, the effects of natural compounds on the pathogenesis of SCI were evaluated by a comprehensive review using electronic databases, such as PubMed, Web of Science, Scopus, and Medline, combined with our expertise in neuropathology. In particular, we reviewed the pathogenesis of SCI, including the importance of secondary nerve injury after the primary mechanical injury, the roles of the mTOR signaling pathways, and the beneficial effects and mechanisms of natural compounds that regulate the mTOR signaling pathway on pathological changes post-SCI, including effects on inflammation, neuronal apoptosis, autophagy, nerve regeneration, and other pathways. This recent research highlights the value of natural compounds in regulating the mTOR pathway, providing a basis for developing novel therapeutic strategies for SCI.
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Affiliation(s)
- Yan Du
- Department of Emergency Medicine, Shengjing Hospital of China Medical University, Shenyang, Liaoning, PR China
| | - Xue Cai
- Department of Emergency Medicine, Shengjing Hospital of China Medical University, Shenyang, Liaoning, PR China.
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4
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Chen L, Hu Y, Wang S, Cao K, Mai W, Sha W, Ma H, Zeng LH, Xu ZZ, Gao YJ, Duan S, Wang Y, Gao Z. mTOR-neuropeptide Y signaling sensitizes nociceptors to drive neuropathic pain. JCI Insight 2022; 7:159247. [PMID: 36194480 DOI: 10.1172/jci.insight.159247] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 09/29/2022] [Indexed: 12/15/2022] Open
Abstract
Neuropathic pain is a refractory condition that involves de novo protein synthesis in the nociceptive pathway. The mTOR is a master regulator of protein translation; however, mechanisms underlying its role in neuropathic pain remain elusive. Using the spared nerve injury-induced neuropathic pain model, we found that mTOR was preferentially activated in large-diameter dorsal root ganglion (DRG) neurons and spinal microglia. However, selective ablation of mTOR in DRG neurons, rather than microglia, alleviated acute neuropathic pain in mice. We show that injury-induced mTOR activation promoted the transcriptional induction of neuropeptide Y (Npy), likely via signal transducer and activator of transcription 3 phosphorylation. NPY further acted primarily on Y2 receptors (Y2R) to enhance neuronal excitability. Peripheral replenishment of NPY reversed pain alleviation upon mTOR removal, whereas Y2R antagonists prevented pain restoration. Our findings reveal an unexpected link between mTOR and NPY/Y2R in promoting nociceptor sensitization and neuropathic pain.
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Affiliation(s)
- Lunhao Chen
- Spine Lab, Department of Orthopedic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yaling Hu
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Liangzhu Laboratory, Zhejiang University Medical Center, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou, China.,NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou, China
| | - Siyuan Wang
- Spine Lab, Department of Orthopedic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Kelei Cao
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Liangzhu Laboratory, Zhejiang University Medical Center, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou, China.,NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou, China
| | - Weihao Mai
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Liangzhu Laboratory, Zhejiang University Medical Center, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou, China
| | - Weilin Sha
- Institute of Pain Medicine and Special Environmental Medicine, Nantong University, Nantong, China
| | - Huan Ma
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Liangzhu Laboratory, Zhejiang University Medical Center, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou, China.,NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou, China
| | - Ling-Hui Zeng
- Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang Province, School of Medicine, Zhejiang University City College, Hangzhou, China
| | - Zhen-Zhong Xu
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Liangzhu Laboratory, Zhejiang University Medical Center, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou, China.,NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou, China
| | - Yong-Jing Gao
- Institute of Pain Medicine and Special Environmental Medicine, Nantong University, Nantong, China
| | - Shumin Duan
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Liangzhu Laboratory, Zhejiang University Medical Center, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou, China.,NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou, China
| | - Yue Wang
- Spine Lab, Department of Orthopedic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Zhihua Gao
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Liangzhu Laboratory, Zhejiang University Medical Center, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou, China.,NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou, China
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5
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Alotaibi M, Al-Aqil F, Alqahtani F, Alanazi M, Nadeem A, Ahmad SF, Lapresa R, Alharbi M, Alshammari A, Alotaibi M, Saleh T, Alrowis R. Alleviation of cisplatin-induced neuropathic pain, neuronal apoptosis, and systemic inflammation in mice by rapamycin. Front Aging Neurosci 2022; 14:891593. [PMID: 36248001 PMCID: PMC9554141 DOI: 10.3389/fnagi.2022.891593] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 08/15/2022] [Indexed: 11/30/2022] Open
Abstract
Platinum-based chemotherapeutic treatment of cancer patients is associated with debilitating adverse effects. Several adverse effects have been well investigated, and can be managed satisfactorily, but chemotherapy-induced peripheral neuropathy (CIPN) remains poorly treated. Our primary aim in this study was to investigate the neuroprotective effect of the immunomodulatory drug rapamycin in the mitigation of cisplatin-induced neurotoxicity. Pain assays were performed in vivo to determine whether rapamycin would prevent or significantly decrease cisplatin-induced neurotoxicity in adult male Balb/c mice. Neuropathic pain induced by both chronic and acute exposure to cisplatin was measured by hot plate assay, cold plate assay, tail-flick test, and plantar test. Rapamycin co-treatment resulted in significant reduction in cisplatin-induced nociceptive-like symptoms. To understand the underlying mechanisms behind rapamycin-mediated neuroprotection, we investigated its effect on certain inflammatory mediators implicated in the propagation of chemotherapy-induced neurotoxicity. Interestingly, cisplatin was found to significantly increase peripheral IL-17A expression and CD8- T cells, which were remarkably reversed by the pre-treatment of mice with rapamycin. In addition, rapamycin reduced the cisplatin-induced neuronal apoptosis marked by decreased neuronal caspase-3 activity. The rapamycin neuroprotective effect was also associated with reversal of the changes in protein expression of p21Cip1, p53, and PUMA. Collectively, rapamycin alleviated some features of cisplatin-induced neurotoxicity in mice and can be further investigated for the treatment of cisplatin-induced peripheral neuropathy.
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Affiliation(s)
- Moureq Alotaibi
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
- *Correspondence: Moureq Alotaibi,
| | - Faten Al-Aqil
- Deanship of Scientific Research, King Saud University, Riyadh, Saudi Arabia
| | - Faleh Alqahtani
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Miteb Alanazi
- Pharmacy Services, King Saud University Medical City, Riyadh, Saudi Arabia
| | - Ahmed Nadeem
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Sheikh F. Ahmad
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Rebeca Lapresa
- Institute of Functional Biology and Genomics, Consejo Superior de Investigaciones Científicas (CSIC), University of Salamanca, Salamanca, Spain
- Institute of Biomedical Research of Salamanca, University Hospital of Salamanca, Consejo Superior de Investigaciones Científicas (CSIC), University of Salamanca, Salamanca, Spain
| | - Metab Alharbi
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Abdulrahman Alshammari
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Muteb Alotaibi
- Department of Neurology, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Tareq Saleh
- Department of Basic Medical Sciences, Faculty of Medicine, The Hashemite University, Zarqa, Jordan
| | - Raed Alrowis
- Department of Periodotics and Community Dentistry, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
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6
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Zhou K, Wu Q, Yue J, Yu X, Ying X, Chen X, Zhou Y, Yang G, Tu W, Jiang S. Electroacupuncture suppresses spinal nerve ligation-induced neuropathic pain via regulation of synaptic plasticity through upregulation of basic fibroblast growth factor expression. Acupunct Med 2022; 40:379-388. [PMID: 35100811 DOI: 10.1177/09645284211066499] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Background: Improving synaptic plasticity is a good way to alleviate neuropathic pain. Electroacupuncture (EA) is currently used worldwide to treat this disease, but its specific mechanisms of action need further investigation. Evidence has suggested that basic fibroblast growth factor (bFGF) plays an important role in promoting nerve regeneration and can promote the expression of vascular endothelial growth factor (VEGF). Objective: In this study, we examined the effects of EA on synaptic plasticity and its underlying mechanism. Methods: A spinal nerve ligation (SNL) rat model was established. NSC37204 (a specific inhibitor of bFGF) was used to determine the relationship between bFGF and putative EA-mediated improvements in synaptic plasticity. Mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) were assessed to evaluate hyperalgesia in rats with SNL. Tissue morphology was detected by hematoxylin–eosin (HE) and Nissl staining, while neural plasticity and its molecular mechanisms were examined by Western blotting, quantitative real-time polymerase chain reaction (qPCR), dual-label immunohistochemistry and transmission electron microscopy. Results: We found that EA improved synaptic plasticity, consistent with higher levels of expression of bFGF and VEGF. Contrary to the beneficial effects of EA, NSC37204 promoted synaptic reconstruction. Furthermore, EA-induced improvements in the neurobehavioral state and improved synaptic plasticity were blocked by NSC37204, consistent with lower expression levels of bFGF and VEGF. Conclusion: These findings indicate that EA suppresses SNL-induced neuropathic pain by improving synaptic plasticity via upregulation of bFGF expression.
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Affiliation(s)
- Kecheng Zhou
- Department of Physical Medicine and Rehabilitation, The Second Affiliated Hospital and Yuying Children’s Hospital, China-USA Institute for Acupuncture and Rehabilitation, Wenzhou Medical University, Wenzhou, P.R. China
- Integrative & Optimized Medicine Research Center, China-USA Institute for Acupuncture and Rehabilitation, Wenzhou Medical University, Wenzhou, P.R. China
| | - Qiaoyun Wu
- Department of Physical Medicine and Rehabilitation, The Second Affiliated Hospital and Yuying Children’s Hospital, China-USA Institute for Acupuncture and Rehabilitation, Wenzhou Medical University, Wenzhou, P.R. China
- Integrative & Optimized Medicine Research Center, China-USA Institute for Acupuncture and Rehabilitation, Wenzhou Medical University, Wenzhou, P.R. China
| | - Jingjing Yue
- Department of Physical Medicine and Rehabilitation, The Second Affiliated Hospital and Yuying Children’s Hospital, China-USA Institute for Acupuncture and Rehabilitation, Wenzhou Medical University, Wenzhou, P.R. China
- Integrative & Optimized Medicine Research Center, China-USA Institute for Acupuncture and Rehabilitation, Wenzhou Medical University, Wenzhou, P.R. China
| | - Xiaolan Yu
- Department of Physical Medicine and Rehabilitation, The Second Affiliated Hospital and Yuying Children’s Hospital, China-USA Institute for Acupuncture and Rehabilitation, Wenzhou Medical University, Wenzhou, P.R. China
- Integrative & Optimized Medicine Research Center, China-USA Institute for Acupuncture and Rehabilitation, Wenzhou Medical University, Wenzhou, P.R. China
| | - Xinwang Ying
- Department of Physical Medicine and Rehabilitation, The Second Affiliated Hospital and Yuying Children’s Hospital, China-USA Institute for Acupuncture and Rehabilitation, Wenzhou Medical University, Wenzhou, P.R. China
- Integrative & Optimized Medicine Research Center, China-USA Institute for Acupuncture and Rehabilitation, Wenzhou Medical University, Wenzhou, P.R. China
| | - Xiaolong Chen
- Department of Physical Medicine and Rehabilitation, The Second Affiliated Hospital and Yuying Children’s Hospital, China-USA Institute for Acupuncture and Rehabilitation, Wenzhou Medical University, Wenzhou, P.R. China
- Integrative & Optimized Medicine Research Center, China-USA Institute for Acupuncture and Rehabilitation, Wenzhou Medical University, Wenzhou, P.R. China
| | - Ye Zhou
- Department of Physical Medicine and Rehabilitation, The Second Affiliated Hospital and Yuying Children’s Hospital, China-USA Institute for Acupuncture and Rehabilitation, Wenzhou Medical University, Wenzhou, P.R. China
- Integrative & Optimized Medicine Research Center, China-USA Institute for Acupuncture and Rehabilitation, Wenzhou Medical University, Wenzhou, P.R. China
| | - Guanhu Yang
- Department of Physical Medicine and Rehabilitation, The Second Affiliated Hospital and Yuying Children’s Hospital, China-USA Institute for Acupuncture and Rehabilitation, Wenzhou Medical University, Wenzhou, P.R. China
- Integrative & Optimized Medicine Research Center, China-USA Institute for Acupuncture and Rehabilitation, Wenzhou Medical University, Wenzhou, P.R. China
| | - Wenzhan Tu
- Department of Physical Medicine and Rehabilitation, The Second Affiliated Hospital and Yuying Children’s Hospital, China-USA Institute for Acupuncture and Rehabilitation, Wenzhou Medical University, Wenzhou, P.R. China
- Integrative & Optimized Medicine Research Center, China-USA Institute for Acupuncture and Rehabilitation, Wenzhou Medical University, Wenzhou, P.R. China
| | - Songhe Jiang
- Department of Physical Medicine and Rehabilitation, The Second Affiliated Hospital and Yuying Children’s Hospital, China-USA Institute for Acupuncture and Rehabilitation, Wenzhou Medical University, Wenzhou, P.R. China
- Integrative & Optimized Medicine Research Center, China-USA Institute for Acupuncture and Rehabilitation, Wenzhou Medical University, Wenzhou, P.R. China
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Korneeva NL. Integrated Stress Response in Neuronal Pathology and in Health. BIOCHEMISTRY. BIOKHIMIIA 2022; 87:S111-S127. [PMID: 35501991 DOI: 10.1134/s0006297922140103] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 10/29/2021] [Accepted: 11/02/2021] [Indexed: 06/14/2023]
Abstract
Neurodegeneration involves progressive pathological loss of a specific population of neurons, glial activation, and dysfunction of myelinating oligodendrocytes leading to cognitive impairment and altered movement, breathing, and senses. Neuronal degeneration is a hallmark of aging, stroke, drug abuse, toxic chemical exposure, viral infection, chronic inflammation, and a variety of neurological diseases. Accumulation of intra- and extracellular protein aggregates is a common characteristic of cell pathologies. Excessive production of reactive oxygen species and nitric oxide, induction of endoplasmic reticulum stress, and accumulation of misfolded protein aggregates have been shown to trigger a defensive mechanism called integrated stress response (ISR). Activation of ISR is important for synaptic plasticity in learning and memory formation. However, sustaining of ISR may lead to the development of neuronal pathologies and altered patterns in behavior and perception.
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Affiliation(s)
- Nadejda L Korneeva
- Louisiana State University Health Science Center, Shreveport, LA 71103, USA.
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8
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Ding Y, Chen Q. mTOR pathway: A potential therapeutic target for spinal cord injury. Biomed Pharmacother 2021; 145:112430. [PMID: 34800780 DOI: 10.1016/j.biopha.2021.112430] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 11/09/2021] [Accepted: 11/12/2021] [Indexed: 12/12/2022] Open
Abstract
Spinal cord injury (SCI) is the most common disabling spinal injury, and the complex pathological process can eventually lead to severe neurological dysfunction. Many studies have reported that the mammalian target of rapamycin (mTOR) signaling pathway plays an important role in synaptogenesis, neuron growth, differentiation, and survival after central nervous system injury. It is also involved in various traumatic and central nervous system diseases, including traumatic brain injury, neonatal hypoxic-ischemic brain injury, Alzheimer's disease, Parkinson's disease, and cerebral apoplexy. mTOR has also been reported to play an important regulatory role in various pathophysiological processes following SCI. Activation of mTOR signals after SCI can regulate physiological and pathological processes, such as proliferation and differentiation of neural stem cells, regeneration of nerve axons, neuroinflammation, and glial scar formation, through various pathways. Inhibition of mTOR activity has been confirmed to promote repair in SCI. At present, many studies have reported that Chinese herbal medicine can inhibit the SCI-activated mTOR pathway to improve the microenvironment and promote nerve repair after SCI. Due to the role of the mTOR pathway in SCI, it may be a potential therapeutic target for SCI. This review is focused on the pathophysiological process of SCI, characteristics of the mTOR pathway, role of the mTOR pathway in SCI, role of inhibition of mTOR on SCI, and role and significance of inhibition of mTOR by related Chinese herbal medicine inhibitors in SCI. In addition, the review discusses the deficiencies and solutions to mTOR and SCI research shortcomings. This study hopes to provide reference for mTOR and SCI research and a theoretical basis for SCI biotherapy.
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Affiliation(s)
- Yi Ding
- Department of Spine Surgery, Ganzhou People's Hospital, 16 Meiguan Avenue, Ganzhou 342800, PR China; The Affiliated Ganzhou Hospital of Nanchang University, Ganzhou 342800, PR China.
| | - Qin Chen
- Department of Spine Surgery, Ganzhou People's Hospital, 16 Meiguan Avenue, Ganzhou 342800, PR China; The Affiliated Ganzhou Hospital of Nanchang University, Ganzhou 342800, PR China.
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9
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Giraud F, Pereira E, Anizon F, Moreau P. Recent Advances in Pain Management: Relevant Protein Kinases and Their Inhibitors. Molecules 2021; 26:molecules26092696. [PMID: 34064521 PMCID: PMC8124620 DOI: 10.3390/molecules26092696] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 04/20/2021] [Accepted: 04/30/2021] [Indexed: 12/16/2022] Open
Abstract
The purpose of this review is to underline the protein kinases that have been established, either in fundamental approach or clinical trials, as potential biological targets in pain management. Protein kinases are presented according to their group in the human kinome: TK (Trk, RET, EGFR, JAK, VEGFR, SFK, BCR-Abl), CMGC (p38 MAPK, MEK, ERK, JNK, ASK1, CDK, CLK2, DYRK1A, GSK3, CK2), AGC (PKA, PKB, PKC, PKMζ, PKG, ROCK), CAMK, CK1 and atypical/other protein kinases (IKK, mTOR). Examples of small molecule inhibitors of these biological targets, demonstrating an analgesic effect, are described. Altogether, this review demonstrates the fundamental role that protein kinase inhibitors could play in the development of new pain treatments.
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10
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Yousuf MS, Shiers SI, Sahn JJ, Price TJ. Pharmacological Manipulation of Translation as a Therapeutic Target for Chronic Pain. Pharmacol Rev 2021; 73:59-88. [PMID: 33203717 PMCID: PMC7736833 DOI: 10.1124/pharmrev.120.000030] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Dysfunction in regulation of mRNA translation is an increasingly recognized characteristic of many diseases and disorders, including cancer, diabetes, autoimmunity, neurodegeneration, and chronic pain. Approximately 50 million adults in the United States experience chronic pain. This economic burden is greater than annual costs associated with heart disease, cancer, and diabetes combined. Treatment options for chronic pain are inadequately efficacious and riddled with adverse side effects. There is thus an urgent unmet need for novel approaches to treating chronic pain. Sensitization of neurons along the nociceptive pathway causes chronic pain states driving symptoms that include spontaneous pain and mechanical and thermal hypersensitivity. More than a decade of preclinical research demonstrates that translational mechanisms regulate the changes in gene expression that are required for ongoing sensitization of nociceptive sensory neurons. This review will describe how key translation regulation signaling pathways, including the integrated stress response, mammalian target of rapamycin, AMP-activated protein kinase (AMPK), and mitogen-activated protein kinase-interacting kinases, impact the translation of different subsets of mRNAs. We then place these mechanisms of translation regulation in the context of chronic pain states, evaluate currently available therapies, and examine the potential for developing novel drugs. Considering the large body of evidence now published in this area, we propose that pharmacologically manipulating specific aspects of the translational machinery may reverse key neuronal phenotypic changes causing different chronic pain conditions. Therapeutics targeting these pathways could eventually be first-line drugs used to treat chronic pain disorders. SIGNIFICANCE STATEMENT: Translational mechanisms regulating protein synthesis underlie phenotypic changes in the sensory nervous system that drive chronic pain states. This review highlights regulatory mechanisms that control translation initiation and how to exploit them in treating persistent pain conditions. We explore the role of mammalian/mechanistic target of rapamycin and mitogen-activated protein kinase-interacting kinase inhibitors and AMPK activators in alleviating pain hypersensitivity. Modulation of eukaryotic initiation factor 2α phosphorylation is also discussed as a potential therapy. Targeting specific translation regulation mechanisms may reverse changes in neuronal hyperexcitability associated with painful conditions.
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Affiliation(s)
- Muhammad Saad Yousuf
- Center for Advanced Pain Studies, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas (M.S.Y., S.I.S., T.J.P.) and 4E Therapeutics Inc, Austin, Texas (J.J.S.)
| | - Stephanie I Shiers
- Center for Advanced Pain Studies, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas (M.S.Y., S.I.S., T.J.P.) and 4E Therapeutics Inc, Austin, Texas (J.J.S.)
| | - James J Sahn
- Center for Advanced Pain Studies, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas (M.S.Y., S.I.S., T.J.P.) and 4E Therapeutics Inc, Austin, Texas (J.J.S.)
| | - Theodore J Price
- Center for Advanced Pain Studies, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas (M.S.Y., S.I.S., T.J.P.) and 4E Therapeutics Inc, Austin, Texas (J.J.S.)
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11
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Martin PY, Doly S, Hamieh AM, Chapuy E, Canale V, Drop M, Chaumont-Dubel S, Bantreil X, Lamaty F, Bojarski AJ, Zajdel P, Eschalier A, Marin P, Courteix C. mTOR activation by constitutively active serotonin6 receptors as new paradigm in neuropathic pain and its treatment. Prog Neurobiol 2020; 193:101846. [DOI: 10.1016/j.pneurobio.2020.101846] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 05/06/2020] [Accepted: 06/02/2020] [Indexed: 02/06/2023]
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12
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Mateos ME, López-Laso E, Vicente J, Ortega R, Vázquez F, Pérez-Navero JL. Response to everolimus of a progressive plexiform neurofibroma in Neurofibromatosis type 1. Pediatr Int 2020; 62:857-859. [PMID: 32027426 DOI: 10.1111/ped.14183] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 10/18/2019] [Accepted: 02/03/2020] [Indexed: 12/14/2022]
Affiliation(s)
- Maria Elena Mateos
- Pediatric Oncology Unit, Department of Pediatrics, Reina Sofia University Hospital, Córdoba, Spain.,Maimonides Institute for Research in Biomedicine of Córdoba (IMIBIC), Reina Sofia University Hospital, Córdoba, Spain
| | - Eduardo López-Laso
- Maimonides Institute for Research in Biomedicine of Córdoba (IMIBIC), Reina Sofia University Hospital, Córdoba, Spain.,Neuropediatric Unit, Department of Pediatrics, Reina Sofia University Hospital, Córdoba, Spain
| | - Josefina Vicente
- Pediatric Radiology Unit, Department of Radiology, Reina Sofia University Hospital, Córdoba, Spain
| | - Rosa Ortega
- Maimonides Institute for Research in Biomedicine of Córdoba (IMIBIC), Reina Sofia University Hospital, Córdoba, Spain.,Department of Pathology, Reina Sofia University Hospital, Córdoba, Spain
| | - Fernando Vázquez
- Maimonides Institute for Research in Biomedicine of Córdoba (IMIBIC), Reina Sofia University Hospital, Córdoba, Spain.,Department of Pediatric Surgery, Reina Sofia University Hospital, Córdoba, Spain
| | - Juan Luis Pérez-Navero
- Pediatric Oncology Unit, Department of Pediatrics, Reina Sofia University Hospital, Córdoba, Spain.,Maimonides Institute for Research in Biomedicine of Córdoba (IMIBIC), Reina Sofia University Hospital, Córdoba, Spain
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13
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Wang R, Qiu Z, Wang G, Hu Q, Shi N, Zhang Z, Wu Y, Zhou C. Quercetin attenuates diabetic neuropathic pain by inhibiting mTOR/p70S6K pathway-mediated changes of synaptic morphology and synaptic protein levels in spinal dorsal horn of db/db mice. Eur J Pharmacol 2020; 882:173266. [PMID: 32553736 DOI: 10.1016/j.ejphar.2020.173266] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Revised: 06/04/2020] [Accepted: 06/08/2020] [Indexed: 01/27/2023]
Abstract
Numerous studies indicate that the changes of synaptic morphology and synaptic protein levels in spinal dorsal horn neurons contributes to the development and maintenance of neuropathic pain. Quercetin, a bioflavonoid compound, has been shown to have analgesic effect in several pain models. However, the underlying mechanism for quercetin to allieviate pain is unclear. Therefore, in this study, we observed the effect of quercetin on diabetic neuropathic pain in db/db mice and explored the underlying mechanisms. Our results showed that chronic quercetin treatment alleviated thermal hyperalgesia in db/db mice. Moreover, quercetin administration significantly reduced the total dendritic length, the number of dendritic branches, and the dendritic spine density in the spinal dorsal horn neurons of db/db mice. Meanwhile, the up-regulated expressions of synaptic plasticity-associated proteins postsynaptic density protein 95 (PSD-95) and synaptophysin in spinal dorsal horn of db/db mice were decreased by quercetin treatment. In addition, quercetin treatment reduced the phosphorylated levels of mammalian target of rapamycin (mTOR) and p70 ribosomal S6 kinase (p70S6K) in spinal dorsal horn of db/db mice. These results demonstrate that quercetin may alleviate diabetic neuropathic pain by inhibiting mTOR/p70S6K pathway-mediated changes of synaptic morphology and synaptic protein levels in spinal dorsal horn neurons of db/db mice. These findings suggest that quercetin may be a promising therapeutic drug in neuropathic pain.
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Affiliation(s)
- Ruiyao Wang
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, China
| | - Zhuang Qiu
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, China
| | - Guizhi Wang
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, China
| | - Qian Hu
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, China
| | - Naihao Shi
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, China
| | - Zongqin Zhang
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, China
| | - Yuqing Wu
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, China.
| | - Chenghua Zhou
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, China.
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14
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He WY, Zhang B, Zhao WC, He J, Wang Y, Zhang L, Xiong QM, Wang HB. mTOR activation due to APPL1 deficiency exacerbates hyperalgesia via Rab5/Akt and AMPK signaling pathway in streptozocin-induced diabetic rats. Mol Pain 2020; 15:1744806919880643. [PMID: 31530215 PMCID: PMC6878613 DOI: 10.1177/1744806919880643] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Painful diabetic neuropathy is a common complication of diabetes mellitus with obscure underlying mechanisms. The adaptor protein APPL1 is critical in mediating the insulin sensitizing and insulin signaling. In neurons, APPL1 reportedly affects synaptic plasticity, while its role in the pathogenesis of painful diabetic neuropathy is masked. Our Western blotting revealed significantly decreased APPL1 expression in the dorsal horn in streptozocin-induced rats versus the control rats, coupled with concomitant mechanical and thermal hyperalgesia. Afterward, the determination of exact localization of APPL1 in spinal cord by immunofluorescent staining assay revealed highly expressed APPL1 in the lamina of spinal dorsal horn in control rats, with the overexpression in neurons, microglia, and underexpression in astrocytes. The APPL1 expression in laminae I and II was significantly downregulated in painful diabetic neuropathy rats. In addition, APPL1 deficiency or overexpression contributed to the increase or decrease of Map and Bassoon, respectively. The localization and immunoactivity of APPL1 and mammalian target of rapamycin (mTOR) were determined in spinal dorsal horn in painful diabetic neuropathy rats and control rats by immunohistochemistry, suggesting pronounced decrease in APPL1 expression in the superficial layer of the spinal cord in painful diabetic neuropathy rats, with p-mTOR expression markedly augmented. APPL1 knockdown by infection with lentiviral vector facilitated the activation of mTOR and abrogated mechanical withdrawal threshold values in painful diabetic neuropathy rats. Genetically overexpressed APPL1 significantly eliminated the activation of mTOR and resulted in the augmented mechanical withdrawal threshold values and thermal withdrawal latency values. Furthermore, the APPL1 levels affect phosphorylation of adenosine monophosphate-activated protein kinase (AMPK), and Akt, as well as the small GTPase, Rab5 expression in painful diabetic neuropathy rats. Our results uncovered a novel mechanism by which APPL1 deficiency facilitates the mTOR activation and thus exacerbates the hyperalgesia in streptozocin-induced diabetic rats, presumably via the regulation of Rab5/Akt and AMPK signaling pathway.
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Affiliation(s)
- Wan-You He
- Department of Anesthesiology, The First People's Hospital of Foshan, Foshan, China
| | - Bin Zhang
- Department of Anesthesiology, The First People's Hospital of Foshan, Foshan, China
| | - Wei-Cheng Zhao
- Department of Anesthesiology, The First People's Hospital of Foshan, Foshan, China
| | - Jian He
- Department of Anesthesiology, The First People's Hospital of Foshan, Foshan, China
| | - Yunhua Wang
- Department of Anesthesiology, The First People's Hospital of Foshan, Foshan, China
| | - Lei Zhang
- Department of Anesthesiology, The First People's Hospital of Foshan, Foshan, China
| | - Qing-Ming Xiong
- Department of Anesthesiology, The First People's Hospital of Foshan, Foshan, China
| | - Han-Bing Wang
- Department of Anesthesiology, The First People's Hospital of Foshan, Foshan, China
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15
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Abstract
Agrimonia pilosa Ledeb. produces an antinociceptive effect in ICR mice in both chemically induced and thermal pain models. In the present study, we examined the antinociceptive effects of single components isolated from Agrimonia pilosa Ledeb. (AP) extract in ICR mice. Three active compounds isolated from AP, including rutin, luteolin-7-O-glucuronide, and apigenin-7-O-glucuronide, were isolated and identified by comparing EI-MS, 1H-, 13C-NMR, and UV. We studied the antinociceptive effects of three single components administered orally at doses of 10 and 20 mg/kg in monosodium urate (MSU)-treated pain model as measured by von Frey test. Among these compounds, apigenin-7-O-glucuronide was more effective in the production of antinociceptive effects. We further characterized the antinociceptive effects and possible mechanisms of apigenin-7-O-glucuronide in writhing and formalin tests. Oral administration of Apigenin-7-O-glucuronide caused a reduction in the number of writhing and effectively reduced the pain behavior observed during the second phase of the formalin test in a dose-dependent manner. In addition, the pretreatment of yohimbine instead of naloxone or methysergide attenuated apigenin-7-O-glucuronide-induced antinociception in the writhing test. Moreover, apigenin-7-O-glucuronide caused reduction in the expression of p-P38, p-CREB, and p-mTOR induced by formalin injection. Our results indicate that apigenin-7-O-glucuronide shows an antinociceptive effect in various pain models. In addition, spinal α2-adrenergic receptors appear to be involved in the production of antinociception induced by apigenin-7-O-glucuronide. Furthermore, the antinociceptive effect of apigenin-7-O-glucuronide appears to be mediated by reduction in the expression of p-P38, p-CREB and p-mTOR levels in the spinal cord.
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16
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He WY, Zhang B, Zhao WC, He J, Zhang L, Xiong QM, Wang J, Wang HB. Contributions of mTOR Activation-Mediated Upregulation of Synapsin II and Neurite Outgrowth to Hyperalgesia in STZ-Induced Diabetic Rats. ACS Chem Neurosci 2019; 10:2385-2396. [PMID: 30785256 DOI: 10.1021/acschemneuro.8b00680] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Painful diabetic neuropathy (PDN) is among the common complications in diabetes mellitus (DM), with its underlying mechanisms largely unknown. Synapsin II is primarily expressed in the spinal dorsal horn, and its upregulation mediates a superfluous release of glutamate and a deficiency of GABAergic interneuron synaptic transmission, which is directly implicated in the facilitation of pain signals in the hyperalgesic nociceptive response. Recently, synapsin II has been revealed to be associated with the modulation of neurite outgrowth, whereas the process of this neuronal structural neuroplasticity following neuronal hyperexcitability still remains unclear. In this study, we found that under conditions of elevated glucose, TNF-α induced the activation of mTOR, mediating the upregulation of synapsin II and neurite outgrowth in dorsal horn neurons. In vivo, we demonstrated that mTOR and synapsin II were upregulated and coexpressed in the spinal dorsal horn neurons in rats with streptozotocin (STZ)-induced diabetes. Furthermore, the intrathecal administration of the mTOR inhibitor rapamycin or synapsin II shRNA significantly diminished the expression of synapsin II, effectively mitigating hyperalgesia in PDN rats. We are the first to discover that in STZ-induced diabetic rats the activation of mTOR mediates the upregulation of synapsin II and neurite outgrowth, both contributing to hyperalgesia. These findings may benefit the clinical therapy of PDN by provision of a novel target.
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Affiliation(s)
- Wan-you He
- Department of Anesthesiology, The First People’s Hospital of Foshan, 81# North of Ling Nan Road, Foshan 528000, China
| | - Bin Zhang
- Department of Anesthesiology, The First People’s Hospital of Foshan, 81# North of Ling Nan Road, Foshan 528000, China
| | - Wei-cheng Zhao
- Department of Anesthesiology, The First People’s Hospital of Foshan, 81# North of Ling Nan Road, Foshan 528000, China
| | - Jian He
- Department of Anesthesiology, The First People’s Hospital of Foshan, 81# North of Ling Nan Road, Foshan 528000, China
| | - Lei Zhang
- Department of Anesthesiology, The First People’s Hospital of Foshan, 81# North of Ling Nan Road, Foshan 528000, China
| | - Qing-ming Xiong
- Department of Anesthesiology, The First People’s Hospital of Foshan, 81# North of Ling Nan Road, Foshan 528000, China
| | - Jing Wang
- Department of Anesthesiology, The First People’s Hospital of Foshan, 81# North of Ling Nan Road, Foshan 528000, China
| | - Han-bing Wang
- Department of Anesthesiology, The First People’s Hospital of Foshan, 81# North of Ling Nan Road, Foshan 528000, China
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17
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Li S, Guan S, Wang Y, Cheng L, Yang Q, Tian Z, Zhao M, Wang X, Feng B. Nicotine inhibits rapamycin-induced pain through activating mTORC1/S6K/IRS-1-related feedback inhibition loop. Brain Res Bull 2019; 149:75-85. [PMID: 31005665 DOI: 10.1016/j.brainresbull.2019.04.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 04/11/2019] [Accepted: 04/16/2019] [Indexed: 11/19/2022]
Abstract
Mammalian target of rapamycin complex 1 (mTORC1) inhibitors increase the incidence of pain in patients, and this finding has been replicated in animal models. However, reports on possible analgesics for this condition are scant. Accumulating evidence finds that nicotinic acetylcholine receptors (nAChRs) are involved in mediating pain. However, whether nicotine, a full agonist of nAChRs, alleviates mTORC1 inhibition-induced pain and its underlying mechanisms remain unknown. In this study, pain was induced in naïve male C57BL/6J mice by intraperitoneally injecting rapamycin acutely or repeatedly. Subsequently, pain thresholds, including mechanical and thermal pain, were measured. The involving signaling pathway was tested using western blot analysis and immunofluorescent assay. Changes in neuronal excitability caused by different treatments were also analyzed using whole-cell recording. Microinjection into the anterior cingulate cortex (ACC) was used to test the role of nAChRs containing the α4β2 or α7 subtype in this brain region in pain modulation. Our results showed that nicotine significantly reduced hyperalgesia in mice that received acute or repeated rapamycin injections, and reversed the effects of rapamycin on the phosphorylation of S6K, 4E-BP1, insulin receptor substrate-1 (IRS-1) at Ser636/639, AKT at Ser473, and ERK at Thr202/Tyr204. Whole-cell recording results showed that nicotine reduced the firing rates of pyramidal neurons in the ACC, and a pharmacological blockade of nAChRs containing the α4β2 or α7 subtype in ACC inhibited the antinociceptive effects of nicotine in mice with rapamycin-induced pain. Our findings indicate that analgesics targeting nAChRs can be developed to help patients with rapamycin-induced pain.
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Affiliation(s)
- Shuo Li
- Department of Pharmacology, School of Pharmacy, Fourth Military Medical University, Xi'an, China; State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Beijing, 100850, China
| | - Shaoyu Guan
- Department of Pharmacology, School of Pharmacy, Fourth Military Medical University, Xi'an, China
| | - Yurong Wang
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi International Joint Research Center for Oral Diseases, Department of Pharmacy, School of Stomatology, Fourth Military Medical University, Xi'an, China; College of Pharmacy, Shaanxi University of Chinese Medicine, Xianyang, China
| | - Lifei Cheng
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi International Joint Research Center for Oral Diseases, Department of Pharmacy, School of Stomatology, Fourth Military Medical University, Xi'an, China
| | - Qi Yang
- Department of Pharmacology, School of Pharmacy, Fourth Military Medical University, Xi'an, China
| | - Zhen Tian
- Department of Pharmacology, School of Pharmacy, Fourth Military Medical University, Xi'an, China
| | - Minggao Zhao
- Department of Pharmacology, School of Pharmacy, Fourth Military Medical University, Xi'an, China
| | - Xiaojuan Wang
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi International Joint Research Center for Oral Diseases, Department of Pharmacy, School of Stomatology, Fourth Military Medical University, Xi'an, China
| | - Bin Feng
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi International Joint Research Center for Oral Diseases, Department of Pharmacy, School of Stomatology, Fourth Military Medical University, Xi'an, China.
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18
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Gui Y, Duan S, Xiao L, Tang J, Li A. Bexarotent Attenuated Chronic Constriction Injury-Induced Spinal Neuroinflammation and Neuropathic Pain by Targeting Mitogen-Activated Protein Kinase Phosphatase-1. THE JOURNAL OF PAIN 2019; 21:1149-1159. [PMID: 30660765 DOI: 10.1016/j.jpain.2019.01.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 12/23/2018] [Accepted: 01/16/2019] [Indexed: 02/06/2023]
Abstract
It is widely accepted that neuroinflammation in the spinal cord contributes to the development of central sensitization in neuropathic pain. Mitogen-activated protein kinase (MAPK) activation plays a vital role in the development of neuroinflammation in the spinal cord. In this study, we investigated the effect of bexarotene (bex), a retinoid X receptor agonist, on MAPKs activation in chronic constriction injury (CCI)-induced neuropathic pain. The data showed that daily treatment with bex 50 mg/kg significantly alleviated CCI-induced nociceptive hypersensitivity in rats. Bex 50 mg/kg/day inhibited CCI-induced MAPKs (p38MAPK, ERK1/2, and JNK) activation and upregulation of proinflammatory factors (IL-1β, tumor necrosis factor-α and IL-6). Bex also reversed CCI-induced microglia activation in the ipsilateral spinal cord. Furthermore, bex treatment significantly upregulated MKP-1 in the spinal cord. These effects were completely abrogated by MKP-1 inhibitor BCI. These results indicated that bex relieved CCI-induced neuroinflammation and neuropathic pain by targeting MKP-1. Therefore, bex might be a potential agent for the treatment of neuropathic pain. PERSPECTIVE: Bex could relieve neuropathic pain behaviors in animals by reversing MKP-1 downregulation and MAPKs activation in the spinal cord. Therapeutic applications of bex may be extended beyond cutaneous T-cell lymphoma.
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Affiliation(s)
- Yulong Gui
- Department of Anesthesiology, Maternal and Child Hospital of Hunan Province, Changsha, Hunan, China
| | - Shunyuan Duan
- Department of Endocrinology, Yongzhou-affiliated Hospital of University of South China, Yongzhou, Hunan Province, China
| | - Lihong Xiao
- Department of Anesthesiology, Maternal and Child Hospital of Hunan Province, Changsha, Hunan, China
| | - Jing Tang
- Department of Anesthesiology, Maternal and Child Hospital of Hunan Province, Changsha, Hunan, China
| | - Aiyuan Li
- Department of Anesthesiology, Maternal and Child Hospital of Hunan Province, Changsha, Hunan, China.
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19
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Feng XL, Deng HB, Wang ZG, Wu Y, Ke JJ, Feng XB. Suberoylanilide Hydroxamic Acid Triggers Autophagy by Influencing the mTOR Pathway in the Spinal Dorsal Horn in a Rat Neuropathic Pain Model. Neurochem Res 2018; 44:450-464. [PMID: 30560396 DOI: 10.1007/s11064-018-2698-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Revised: 11/05/2018] [Accepted: 12/10/2018] [Indexed: 02/08/2023]
Abstract
Histone acetylation levels can be upregulated by treating cells with histone deacetylase inhibitors (HDACIs), which can induce autophagy. Autophagy flux in the spinal cord of rats following the left fifth lumber spinal nerve ligation (SNL) is involved in the progression of neuropathic pain. Suberoylanilide hydroxamic acid (SAHA), one of the HDACIs can interfere with the epigenetic process of histone acetylation, which has been shown to ease neuropathic pain. Recent research suggest that SAHA can stimulate autophagy via the mammalian target of rapamycin (mTOR) pathway in some types of cancer cells. However, little is known about the role of SAHA and autophagy in neuropathic pain after nerve injury. In the present study, we aim to investigate autophagy flux and the role of the mTOR pathway on spinal cells autophagy activation in neuropathic pain induced by SNL in rats that received SAHA treatment. Autophagy-related proteins and mTOR or its active form were assessed by using western blot, immunohistochemistry, double immunofluorescence staining and transmission electron microscopy (TEM). We found that SAHA decreased the paw mechanical withdrawal threshold (PMWT) of the lower compared with SNL. Autophagy flux was mainly disrupted in the astrocytes and neuronal cells of the spinal cord dorsal horn on postsurgical day 28 and was reversed by daily intrathecal injection of SAHA (n = 100 nmol/day or n = 200 nmol/day). SAHA also decreased mTOR and phosphorylated mTOR (p-mTOR) expression, especially p-mTOR expression in astrocytes and neuronal cells of the spinal dorsal horn. These results suggest that SAHA attenuates neuropathic pain and contributes to autophagy flux in astrocytes and neuronal cells of the spinal dorsal horn via the mTOR signaling pathway.
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Affiliation(s)
- Xiang-Lan Feng
- Department of Anesthesiology, Zhongnan Hospital of Wuhan University, No. 169 Donghu Rd, Wuhan, 430071, Hubei, China
| | - Hong-Bo Deng
- Department of Anesthesiology, Zhongnan Hospital of Wuhan University, No. 169 Donghu Rd, Wuhan, 430071, Hubei, China
| | - Zheng-Gang Wang
- Department of Anesthesiology, Zhongnan Hospital of Wuhan University, No. 169 Donghu Rd, Wuhan, 430071, Hubei, China
| | - Yun Wu
- Department of Anesthesiology, Zhongnan Hospital of Wuhan University, No. 169 Donghu Rd, Wuhan, 430071, Hubei, China
| | - Jian-Juan Ke
- Department of Anesthesiology, Zhongnan Hospital of Wuhan University, No. 169 Donghu Rd, Wuhan, 430071, Hubei, China
| | - Xiao-Bo Feng
- Department of Anesthesiology, Zhongnan Hospital of Wuhan University, No. 169 Donghu Rd, Wuhan, 430071, Hubei, China.
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20
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Khoutorsky A, Price TJ. Translational Control Mechanisms in Persistent Pain. Trends Neurosci 2018; 41:100-114. [PMID: 29249459 DOI: 10.1016/j.tins.2017.11.006] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 11/14/2017] [Accepted: 11/22/2017] [Indexed: 12/21/2022]
Abstract
Persistent pain, which is poorly treated and estimated to afflict one third of the world's population, is largely mediated by the sensitization of nociceptive neurons. This sensitization involves de novo gene expression to support biochemical and structural changes required to maintain amplified pain signaling that frequently persists even after injury to tissue resolves. While transcription-dependent changes in gene expression are important, recent work demonstrates that activity-dependent regulation of mRNA translation is key to controlling the cellular proteome and the development and maintenance of persistent pain. In this review, we highlight recent advances in translational regulation of gene expression in nociceptive circuits, with a focus on key signaling pathways and mRNA targets that may be tractable for the creation of next-generation pain therapeutics.
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Affiliation(s)
- Arkady Khoutorsky
- Department of Anesthesia and Alan Edwards Centre for Research on Pain, McGill University, Montréal, QC, H3A 0G1, Canada.
| | - Theodore J Price
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX 75080, USA.
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21
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Jang SP, Park SH, Jung JS, Lee HJ, Hong JW, Lee JY, Suh HW. Characterization of changes of pain behavior and signal transduction system in food-deprived mice. Anim Cells Syst (Seoul) 2018; 22:227-233. [PMID: 30460102 PMCID: PMC6138332 DOI: 10.1080/19768354.2018.1490348] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Revised: 05/23/2018] [Accepted: 05/28/2018] [Indexed: 12/18/2022] Open
Abstract
Fasting in general causes several metabolic changes. In the present study, we examined the possible changes of several types of nociception during the food deprivation were investigated in mice. After the mice were forced into the fasting for 12, 24, or 48 h, the changes of nociception were measured by the tail-flick, writhing, formalin or von-frey tests. We found that the nociceptive behavior induced by intraperitoneally (i.p.) administered acetic acid (writhing response) or intraplantar injection of 5% formalin into the hind-paw were reduced in fasted group. In addition, the tail-flick response and threshold for nociception in mechanical von-frey test were also elevated in fasted group. Moreover, the p-CREB and p-ERK levels in the dorsal root ganglia (DRG) and the spinal cord were reduced in food-deprived group. Furthermore, p-AMPKα1 expressions in DRG and the spinal cord were up-regulated, whereas p-mTOR in DRG and the spinal cord was down-regulated in food-deprived group. Our results suggest that the chemical, mechanical, and thermal nociceptions appear to be reduced in a food-deprived mouse group. Additionally, reduction of nociception in food-deprived group appears to be closely associated with the expressions of several signal transduction molecules such as ERK, CREB, AMPKα1 and mTOR proteins in DRG and the spinal cord.
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Affiliation(s)
- Sang-Pil Jang
- Department of Pharmacology, Institute of Natural Medicine, College of Medicine, Hallym University, Chuncheon, Korea
| | - Seong-Hwan Park
- Department of Pharmacology, Institute of Natural Medicine, College of Medicine, Hallym University, Chuncheon, Korea
| | - Jun-Sub Jung
- Department of Pharmacology, Institute of Natural Medicine, College of Medicine, Hallym University, Chuncheon, Korea
| | - Hee-Jung Lee
- Department of Life science, Hallym University, Chuncheon, Korea
| | - Jung-Woo Hong
- Department of Biomedical Science, Hallym University, Chuncheon, Korea
| | - Jae-Yong Lee
- Department of Biochemistry, College of Medicine, Hallym University, Chuncheon, Korea
| | - Hong-Won Suh
- Department of Pharmacology, Institute of Natural Medicine, College of Medicine, Hallym University, Chuncheon, Korea
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22
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Gui Y, Chen L, Duan S, Li G, Tang J, Li A. Methyl cinnamate alleviated CCI-induced upregualtion of spinal AMPA receptors and pain hypersensitivity by targeting AMPK. Eur J Pharmacol 2018; 833:183-189. [PMID: 29802834 DOI: 10.1016/j.ejphar.2018.05.033] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2018] [Revised: 05/20/2018] [Accepted: 05/22/2018] [Indexed: 12/22/2022]
Abstract
Various studies proved spinal AMPA receptors were involved in the formation of neuropathic pain. In this study, we investigated the effect of methyl cinnamate (MC), a flavoring agent widely used in food and commodity industry, on CCI-induced upregulation of spinal AMPARs and pain hypersensitive behaviors. Results indicated that MC treatment dosage-dependently inhibited CCI-induced mechanical and thermal hypersensitivity. To further investigate the effect of MC after the formation of neuropathic pain, MC at the dosage of 100 mg/kg was administrated on day 7-14 on CCI rats. Results showed that MC treatment for seven days alleviated CCI-induced pain hypersensitivity after the formation of neuropathic pain. MC treatment reversed CCI-induced upregulation of GluR2, GluR3 and phosphorylation of GluR1. Further, MC dosage-dependently alleviated CCI-induced activation of mTOR and the downstream p70s6k. MC dosage-dependently induced activation of AMPK. All the MC-induced effects in CCI rats were completely reversed by Compound C, a AMPK inhibitor. These results meant MC treatment mitigated CCI-induced upregualtion of spinal AMPA receptors and pain hypersensitive behaviors through actviation of AMPK.
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Affiliation(s)
- Yulong Gui
- Department of Anesthesiology, Hunan Provincial Maternal and Child Health Hospital, Changsha 410000, Hunan Province, China
| | - Liang Chen
- Department of Anesthesiology, Hunan Provincial Maternal and Child Health Hospital, Changsha 410000, Hunan Province, China
| | - Shunyuan Duan
- Department of Endocrinology, Yongzhou-affiliated Hospital of University of South China, Yongzhou 425000, Hunan Province, China
| | - Guan Li
- Department of Anesthesiology, Hunan Provincial Maternal and Child Health Hospital, Changsha 410000, Hunan Province, China
| | - Jing Tang
- Department of Anesthesiology, Hunan Provincial Maternal and Child Health Hospital, Changsha 410000, Hunan Province, China
| | - Aiyuan Li
- Department of Anesthesiology, Hunan Provincial Maternal and Child Health Hospital, Changsha 410000, Hunan Province, China.
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Uttam S, Wong C, Amorim IS, Jafarnejad SM, Tansley SN, Yang J, Prager-Khoutorsky M, Mogil JS, Gkogkas CG, Khoutorsky A. Translational profiling of dorsal root ganglia and spinal cord in a mouse model of neuropathic pain. NEUROBIOLOGY OF PAIN 2018; 4:35-44. [PMID: 30906902 PMCID: PMC6428075 DOI: 10.1016/j.ynpai.2018.04.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Translational landscape in DRG and spinal cord in SNI assay of neuropathic pain was established. ERK is a central hub of both transcriptionally and translationally controlled genes. Changes in translation efficiency and mRNA levels occur in the opposite direction for multiple mRNAs.
Acute pain serves as a protective mechanism, guiding the organism away from actual or potential tissue injury. In contrast, chronic pain is a debilitating condition without any obvious physiological function. The transition to, and the maintenance of chronic pain require new gene expression to support biochemical and structural changes within the pain pathway. The regulation of gene expression at the level of mRNA translation has emerged as an important step in the control of protein expression in the cell. Recent studies show that signaling pathways upstream of mRNA translation, such as mTORC1 and ERK, are upregulated in chronic pain conditions, and their inhibition effectively alleviates pain in several animal models. Despite this progress, mRNAs whose translation is altered in chronic pain conditions remain largely unknown. Here, we performed genome-wide translational profiling of dorsal root ganglion (DRG) and spinal cord dorsal horn tissues in a mouse model of neuropathic pain, spared nerve injury (SNI), using the ribosome profiling technique. We identified distinct subsets of mRNAs that are differentially translated in response to nerve injury in both tissues. We discovered key converging upstream regulators and pathways linked to mRNA translational control and neuropathic pain. Our data are crucial for the understanding of mechanisms by which mRNA translation promotes persistent hypersensitivity after nerve injury.
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Affiliation(s)
- Sonali Uttam
- Department of Anesthesia, McGill University, Montreal, QC H3A 0G1, Canada
| | - Calvin Wong
- Department of Anesthesia, McGill University, Montreal, QC H3A 0G1, Canada
| | - Inês S Amorim
- Patrick Wild Centre and Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Seyed Mehdi Jafarnejad
- Department of Biochemistry and Goodman Cancer Research Centre, McGill University, Montreal, QC H3A 1A3, Canada
| | - Shannon N Tansley
- Department of Anesthesia, McGill University, Montreal, QC H3A 0G1, Canada.,Department of Psychology, McGill University, Montreal QC H3A 1B1, Canada
| | - Jieyi Yang
- Department of Anesthesia, McGill University, Montreal, QC H3A 0G1, Canada
| | | | - Jeffrey S Mogil
- Department of Anesthesia, McGill University, Montreal, QC H3A 0G1, Canada.,Department of Psychology, McGill University, Montreal QC H3A 1B1, Canada.,Alan Edwards Centre for Research on Pain, McGill University, Montreal QC H3A 0G1, Canada
| | - Christos G Gkogkas
- Patrick Wild Centre and Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Arkady Khoutorsky
- Department of Anesthesia, McGill University, Montreal, QC H3A 0G1, Canada.,Alan Edwards Centre for Research on Pain, McGill University, Montreal QC H3A 0G1, Canada
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24
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Tansley SN, Wong C, Uttam S, Mogil JS, Khoutorsky A. Translation regulation in the spinal dorsal horn - A key mechanism for development of chronic pain. NEUROBIOLOGY OF PAIN 2018; 4:20-26. [PMID: 30906901 PMCID: PMC6428080 DOI: 10.1016/j.ynpai.2018.03.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Spinal sensitization shares molecular mechanisms with hippocampal LTP and memory. Changes in mRNA translation are observed in many chronic pain conditions. Targeting translational control mechanisms is a promising strategy to inhibit pain. Targeting spinal reconsolidation can reverse established hypersensitivity.
Chronic pain is a pathological condition characterized by long-lasting pain after damaged tissue has healed. Chronic pain can be caused and maintained by changes in various components of the pain pathway, including sensory neurons, spinal cord and higher brain centers. Exaggerated sensitivity and responsiveness of spinal nociceptive circuits, representing maladaptive plasticity, play key roles in the amplification of peripheral signals in chronic pain conditions. This spinal amplification mechanism profoundly contributes to the development and maintenance of chronic pain hypersensitivity in response to peripheral injury, and in some cases occurs independently of the peripheral stimulus. Long-lasting changes in the activity of spinal neurons are caused by alterations in their cellular proteome, which relies on de novo gene expression. Recent evidence indicates that translational control of gene expression plays a major role in determining protein levels, and is intricately involved in different forms of intrinsic and synaptic plasticity. In this review, we summarize findings supporting a key role for translational control in spinal cord-dependent mechanisms of chronic pain, and present recent approaches to reverse persistent pain by targeting these mechanisms.
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Affiliation(s)
- Shannon N Tansley
- Department of Anesthesia, McGill University, Montréal, QC H3A 0G1, Canada.,Department of Psychology, McGill University, Montréal, QC H3A 1B1, Canada
| | - Calvin Wong
- Department of Anesthesia, McGill University, Montréal, QC H3A 0G1, Canada
| | - Sonali Uttam
- Department of Anesthesia, McGill University, Montréal, QC H3A 0G1, Canada
| | - Jeffrey S Mogil
- Department of Anesthesia, McGill University, Montréal, QC H3A 0G1, Canada.,Department of Psychology, McGill University, Montréal, QC H3A 1B1, Canada.,Alan Edwards Centre for Research on Pain, McGill University, Montréal, QC H3A 0G1, Canada
| | - Arkady Khoutorsky
- Department of Anesthesia, McGill University, Montréal, QC H3A 0G1, Canada.,Alan Edwards Centre for Research on Pain, McGill University, Montréal, QC H3A 0G1, Canada
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25
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Beneficial Effects of Resveratrol-Mediated Inhibition of the mTOR Pathway in Spinal Cord Injury. Neural Plast 2018; 2018:7513748. [PMID: 29780409 PMCID: PMC5892236 DOI: 10.1155/2018/7513748] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Revised: 02/03/2018] [Accepted: 02/18/2018] [Indexed: 12/17/2022] Open
Abstract
Spinal cord injury (SCI) causes a high rate of morbidity and disability. The clinical features of SCI are divided into acute, subacute, and chronic phases according to its pathophysiological events. The mammalian target of rapamycin (mTOR) signaling pathway plays an important role in cell death and inflammation in the acute phase and neuroregeneration in the subacute/chronic phases at different times. Resveratrol has the potential of regulating cell growth, proliferation, metabolism, and angiogenesis through the mTOR signaling pathway. Herein, we explicate the role of resveratrol in the repair of SCI through the inhibition of the mTOR signaling pathway. The inhibition of the mTOR pathway by resveratrol has the potential of serving as a neuronal restorative mechanism following SCI.
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26
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Cho C, Michailidis V, Martin LJ. Revealing brain mechanisms of mTOR-mediated translational regulation: Implications for chronic pain. NEUROBIOLOGY OF PAIN 2018; 4:27-34. [PMID: 31194026 PMCID: PMC6550104 DOI: 10.1016/j.ynpai.2018.03.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 03/15/2018] [Accepted: 03/16/2018] [Indexed: 12/27/2022]
Abstract
mTOR is a major regulator of protein translation. mTOR serves an important role in neural plasticity. mTOR signalling in the brain as a pathology for neurological disorder is known. mTOR signalling in the brain as a chronic pain mechanism is understudied.
In the spinal cord, altered protein transcription and translation have received a lot of recent attention for their role in neural plasticity, a major mechanism leading to the development of chronic pain. However, changes in brain plasticity are also associated with the maintenance of pain symptoms, but these cellular mechanisms remain less clear. The mechanistic/mammalian target of rapamycin (mTOR) is a master regulator of protein synthesis, and controls several neuronal functions, including neural plasticity. While aberrant changes in mTOR signaling are associated with sensitization of the pain pathway (sensory neurons and spinal cord), there are various nervous system diseases that have pain as a comorbidity and altered mTOR activity in the brain. Here, we provide a brief review of mTOR changes in the brain that are associated with some neurological disorders and focus on how these changes may be relevant to the pain of the underlying condition and chronic pain itself.
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Affiliation(s)
- Chulmin Cho
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada
| | - Vassilia Michailidis
- Deptartment of Cell and Systems Biology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada
| | - Loren J. Martin
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada
- Deptartment of Cell and Systems Biology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada
- Corresponding author at: Department of Psychology, University of Toronto Mississauga, 3359 Mississauga Rd., Mississauga, ON L5L 1C6, Canada.
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27
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Carlin D, Golden JP, Mogha A, Samineni VK, Monk KR, Gereau RW, Cavalli V. Deletion of Tsc2 in Nociceptors Reduces Target Innervation, Ion Channel Expression, and Sensitivity to Heat. eNeuro 2018; 5:ENEURO.0436-17.2018. [PMID: 29766046 PMCID: PMC5952427 DOI: 10.1523/eneuro.0436-17.2018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 04/13/2018] [Accepted: 04/16/2018] [Indexed: 01/10/2023] Open
Abstract
The mechanistic target of rapamycin complex 1 (mTORC1) is known to regulate cellular growth pathways, and its genetic activation is sufficient to enhance regenerative axon growth following injury to the central or peripheral nervous systems. However, excess mTORC1 activation may promote innervation defects, and mTORC1 activity mediates injury-induced hypersensitivity, reducing enthusiasm for the pathway as a therapeutic target. While mTORC1 activity is required for full expression of some pain modalities, the effects of pathway activation on nociceptor phenotypes and sensory behaviors are currently unknown. To address this, we genetically activated mTORC1 in mouse peripheral sensory neurons by conditional deletion of its negative regulator Tuberous Sclerosis Complex 2 (Tsc2). Consistent with the well-known role of mTORC1 in regulating cell size, soma size and axon diameter of C-nociceptors were increased in Tsc2-deleted mice. Glabrous skin and spinal cord innervation by C-fiber neurons were also disrupted. Transcriptional profiling of nociceptors enriched by fluorescence-associated cell sorting (FACS) revealed downregulation of multiple classes of ion channels as well as reduced expression of markers for peptidergic nociceptors in Tsc2-deleted mice. In addition to these changes in innervation and gene expression, Tsc2-deleted mice exhibited reduced noxious heat sensitivity and decreased injury-induced cold hypersensitivity, but normal baseline sensitivity to cold and mechanical stimuli. Together, these data show that excess mTORC1 activity in sensory neurons produces changes in gene expression, neuron morphology and sensory behavior.
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Affiliation(s)
- Dan Carlin
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110
| | - Judith P. Golden
- Washington University Pain Center and Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110
| | - Amit Mogha
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110
| | - Vijay K. Samineni
- Washington University Pain Center and Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110
| | - Kelly R. Monk
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110
| | - Robert W. Gereau
- Washington University Pain Center and Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110
| | - Valeria Cavalli
- Department of Neuroscience, Hope Center for Neurological Disorders and Center of Regenerative Medicine, Washington University School of Medicine, St. Louis, MO 63110
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28
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Kays J, Zhang YH, Khorodova A, Strichartz G, Nicol GD. Peripheral Synthesis of an Atypical Protein Kinase C Mediates the Enhancement of Excitability and the Development of Mechanical Hyperalgesia Produced by Nerve Growth Factor. Neuroscience 2017; 371:420-432. [PMID: 29288797 DOI: 10.1016/j.neuroscience.2017.12.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 12/18/2017] [Accepted: 12/20/2017] [Indexed: 12/26/2022]
Abstract
Nerve growth factor (NGF) plays a key role in the initiation as well as the prolonged heightened pain sensitivity of the inflammatory response. Previously, we showed that NGF rapidly augmented both the excitability of isolated rat sensory neurons and the mechanical sensitivity of the rat's hind paw. The increase in excitability and sensitivity was blocked by the myristoylated pseudosubstrate inhibitor of atypical PKCs (mPSI), suggesting that an atypical PKC may play a key regulatory role in generating this heightened sensitivity. Our findings raised the question as to whether NGF directs changes in translational control, as suggested for long-lasting long-term potentiation (LTP), or whether NGF leads to the activation of an atypical PKC by other mechanisms. The current studies demonstrate that enhanced action potential (AP) firing produced by NGF was blocked by inhibitors of translation, but not transcription. In parallel, in vitro studies showed that NGF elevated the protein levels of PKMζ, which was also prevented by inhibitors of translation. Intraplantar injection of NGF in the rat hind paw produced a rapid and maintained increase in mechanical sensitivity whose onset was delayed by translation inhibitors. Established NGF-induced hypersensitivity could be transiently reversed by injection of rapamycin or mPSI. These results suggest that NGF produces a rapid increase in the synthesis of PKMζ protein in the paw that augments neuronal sensitivity and that the ongoing translational expression of PKMζ plays a critical role in generating as well as maintaining the heightened sensitivity produced by NGF.
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Affiliation(s)
- Joanne Kays
- Department of Pharmacology and Toxicology, School of Medicine, Indiana University, Indianapolis, IN 46202, United States
| | - Yi Hong Zhang
- Department of Pharmacology and Toxicology, School of Medicine, Indiana University, Indianapolis, IN 46202, United States
| | - Alla Khorodova
- Pain Research Center, Department of Anesthesiology, Perioperative and Pain Medicine, Brigham & Women's Hospital, Harvard Medical School, Boston, MA 02135-6110, United States
| | - Gary Strichartz
- Pain Research Center, Department of Anesthesiology, Perioperative and Pain Medicine, Brigham & Women's Hospital, Harvard Medical School, Boston, MA 02135-6110, United States
| | - Grant D Nicol
- Department of Pharmacology and Toxicology, School of Medicine, Indiana University, Indianapolis, IN 46202, United States.
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29
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Price TJ, Das V, Dussor G. Adenosine Monophosphate-activated Protein Kinase (AMPK) Activators For the Prevention, Treatment and Potential Reversal of Pathological Pain. Curr Drug Targets 2017; 17:908-20. [PMID: 26521775 DOI: 10.2174/1389450116666151102095046] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 10/20/2015] [Accepted: 10/29/2015] [Indexed: 12/23/2022]
Abstract
Pathological pain is an enormous medical problem that places a significant burden on patients and can result from an injury that has long since healed or be due to an unidentifiable cause. Although treatments exist, they often either lack efficacy or have intolerable side effects. More importantly, they do not reverse the changes in the nervous system mediating pathological pain, and thus symptoms often return when therapies are discontinued. Consequently, novel therapies are urgently needed that have both improved efficacy and disease-modifying properties. Here we highlight an emerging target for novel pain therapies, adenosine monophosphate-activated protein kinase (AMPK). AMPK is capable of regulating a variety of cellular processes including protein translation, activity of other kinases, and mitochondrial metabolism, many of which are thought to contribute to pathological pain. Consistent with these properties, preclinical studies show positive, and in some cases disease-modifying effects of either pharmacological activation or genetic regulation of AMPK in models of nerve injury, chemotherapy-induced peripheral neuropathy (CIPN), postsurgical pain, inflammatory pain, and diabetic neuropathy. Given the AMPK-activating ability of metformin, a widely prescribed and well-tolerated drug, these preclinical studies provide a strong rationale for both retrospective and prospective human pain trials with this drug. They also argue for the development of novel AMPK activators, whether orthosteric, allosteric, or modulators of events upstream of the kinase. Together, this review will present the case for AMPK as a novel therapeutic target for pain and will discuss future challenges in the path toward development of AMPK-based pain therapeutics.
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Affiliation(s)
- Theodore J Price
- School of Behavioral and Brain Sciences, University of Texas at Dallas, JO 4.212 800 W Campbell Rd, Richardson TX 75080, USA.
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30
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The MNK-eIF4E Signaling Axis Contributes to Injury-Induced Nociceptive Plasticity and the Development of Chronic Pain. J Neurosci 2017; 37:7481-7499. [PMID: 28674170 DOI: 10.1523/jneurosci.0220-17.2017] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 05/21/2017] [Accepted: 06/27/2017] [Indexed: 12/18/2022] Open
Abstract
Injury-induced sensitization of nociceptors contributes to pain states and the development of chronic pain. Inhibiting activity-dependent mRNA translation through mechanistic target of rapamycin and mitogen-activated protein kinase (MAPK) pathways blocks the development of nociceptor sensitization. These pathways convergently signal to the eukaryotic translation initiation factor (eIF) 4F complex to regulate the sensitization of nociceptors, but the details of this process are ill defined. Here we investigated the hypothesis that phosphorylation of the 5' cap-binding protein eIF4E by its specific kinase MAPK interacting kinases (MNKs) 1/2 is a key factor in nociceptor sensitization and the development of chronic pain. Phosphorylation of ser209 on eIF4E regulates the translation of a subset of mRNAs. We show that pronociceptive and inflammatory factors, such as nerve growth factor (NGF), interleukin-6 (IL-6), and carrageenan, produce decreased mechanical and thermal hypersensitivity, decreased affective pain behaviors, and strongly reduced hyperalgesic priming in mice lacking eIF4E phosphorylation (eIF4ES209A ). Tests were done in both sexes, and no sex differences were found. Moreover, in patch-clamp electrophysiology and Ca2+ imaging experiments on dorsal root ganglion neurons, NGF- and IL-6-induced increases in excitability were attenuated in neurons from eIF4ES209A mice. These effects were recapitulated in Mnk1/2-/- mice and with the MNK1/2 inhibitor cercosporamide. We also find that cold hypersensitivity induced by peripheral nerve injury is reduced in eIF4ES209A and Mnk1/2-/- mice and following cercosporamide treatment. Our findings demonstrate that the MNK1/2-eIF4E signaling axis is an important contributing factor to mechanisms of nociceptor plasticity and the development of chronic pain.SIGNIFICANCE STATEMENT Chronic pain is a debilitating disease affecting approximately one in three Americans. Chronic pain is thought to be driven by changes in the excitability of peripheral nociceptive neurons, but the precise mechanisms controlling these changes are not elucidated. Emerging evidence demonstrates that mRNA translation regulation pathways are key factors in changes in nociceptor excitability. Our work demonstrates that a single phosphorylation site on the 5' cap-binding protein eIF4E is a critical mechanism for changes in nociceptor excitability that drive the development of chronic pain. We reveal a new mechanistic target for the development of a chronic pain state and propose that targeting the upstream kinase, MAPK interacting kinase 1/2, could be used as a therapeutic approach for chronic pain.
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Kwon M, Han J, Kim UJ, Cha M, Um SW, Bai SJ, Hong SK, Lee BH. Inhibition of Mammalian Target of Rapamycin (mTOR) Signaling in the Insular Cortex Alleviates Neuropathic Pain after Peripheral Nerve Injury. Front Mol Neurosci 2017; 10:79. [PMID: 28377693 PMCID: PMC5359287 DOI: 10.3389/fnmol.2017.00079] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 03/06/2017] [Indexed: 12/30/2022] Open
Abstract
Injury of peripheral nerves can trigger neuropathic pain, producing allodynia and hyperalgesia via peripheral and central sensitization. Recent studies have focused on the role of the insular cortex (IC) in neuropathic pain. Because the IC is thought to store pain-related memories, translational regulation in this structure may reveal novel targets for controlling chronic pain. Signaling via mammalian target of rapamycin (mTOR), which is known to control mRNA translation and influence synaptic plasticity, has been studied at the spinal level in neuropathic pain, but its role in the IC under these conditions remains elusive. Therefore, this study was conducted to determine the role of mTOR signaling in neuropathic pain and to assess the potential therapeutic effects of rapamycin, an inhibitor of mTORC1, in the IC of rats with neuropathic pain. Mechanical allodynia was assessed in adult male Sprague-Dawley rats after neuropathic surgery and following microinjections of rapamycin into the IC on postoperative days (PODs) 3 and 7. Optical recording was conducted to observe the neural responses of the IC to peripheral stimulation. Rapamycin reduced mechanical allodynia and downregulated the expression of postsynaptic density protein 95 (PSD95), decreased neural excitability in the IC, thereby inhibiting neuropathic pain-induced synaptic plasticity. These findings suggest that mTOR signaling in the IC may be a critical molecular mechanism modulating neuropathic pain.
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Affiliation(s)
- Minjee Kwon
- Department of Physiology, Yonsei University College of MedicineSeoul, South Korea; Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of MedicineSeoul, South Korea
| | - Jeongsoo Han
- Department of Physiology, Yonsei University College of MedicineSeoul, South Korea; Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of MedicineSeoul, South Korea
| | - Un Jeng Kim
- Department of Physiology, Yonsei University College of Medicine Seoul, South Korea
| | - Myeounghoon Cha
- Department of Physiology, Yonsei University College of Medicine Seoul, South Korea
| | - Sun Woo Um
- Department of Physiology, Yonsei University College of MedicineSeoul, South Korea; Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of MedicineSeoul, South Korea
| | - Sun Joon Bai
- Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine Seoul, South Korea
| | - Seong-Karp Hong
- Division of Bio and Health Sciences, Mokwon University Daejeon, South Korea
| | - Bae Hwan Lee
- Department of Physiology, Yonsei University College of MedicineSeoul, South Korea; Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of MedicineSeoul, South Korea; Brain Research Institute and Epilepsy Research Institute, Yonsei University College of MedicineSeoul, South Korea
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32
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The mTOR signalling cascade: paving new roads to cure neurological disease. Nat Rev Neurol 2016; 12:379-92. [PMID: 27340022 DOI: 10.1038/nrneurol.2016.81] [Citation(s) in RCA: 262] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Defining the multiple roles of the mechanistic (formerly 'mammalian') target of rapamycin (mTOR) signalling pathway in neurological diseases has been an exciting and rapidly evolving story of bench-to-bedside translational research that has spanned gene mutation discovery, functional experimental validation of mutations, pharmacological pathway manipulation, and clinical trials. Alterations in the dual contributions of mTOR - regulation of cell growth and proliferation, as well as autophagy and cell death - have been found in developmental brain malformations, epilepsy, autism and intellectual disability, hypoxic-ischaemic and traumatic brain injuries, brain tumours, and neurodegenerative disorders. mTOR integrates a variety of cues, such as growth factor levels, oxygen levels, and nutrient and energy availability, to regulate protein synthesis and cell growth. In line with the positioning of mTOR as a pivotal cell signalling node, altered mTOR activation has been associated with a group of phenotypically diverse neurological disorders. To understand how altered mTOR signalling leads to such divergent phenotypes, we need insight into the differential effects of enhanced or diminished mTOR activation, the developmental context of these changes, and the cell type affected by altered signalling. A particularly exciting feature of the tale of mTOR discovery is that pharmacological mTOR inhibitors have shown clinical benefits in some neurological disorders, such as tuberous sclerosis complex, and are being considered for clinical trials in epilepsy, autism, dementia, traumatic brain injury, and stroke.
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33
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Ko MH, Yang ML, Youn SC, Lan CT, Tseng TJ. Intact subepidermal nerve fibers mediate mechanical hypersensitivity via the activation of protein kinase C gamma in spared nerve injury. Mol Pain 2016; 12:12/0/1744806916656189. [PMID: 27296621 PMCID: PMC4956387 DOI: 10.1177/1744806916656189] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Spared nerve injury is an important neuropathic pain model for investigating the role of intact primary afferents in the skin on pain hypersensitivity. However, potential cellular mechanisms remain poorly understood. In phosphoinositide-3 kinase pathway, pyruvate dehydrogenase kinase 1 (PDK1) participates in the regulation of neuronal plasticity for central sensitization. The downstream cascades of PDK1 include: (1) protein kinase C gamma (PKCg) controls the trafficking and phosphorylation of ionotropic glutamate receptor; (2) protein kinase B (Akt)/the mammalian target of rapamycin (mTOR) signaling is responsible for local protein synthesis. Under these statements, we therefore hypothesized that an increase of PKCg activation and mTOR-dependent PKCg synthesis in intact primary afferents after SNI might contribute to pain hypersensitivity. RESULTS The variants of spared nerve injury were performed in Sprague-Dawley rats by transecting any two of the three branches of the sciatic nerve, leaving only one branch intact. Following SNIt (spared tibial branch), mechanical hyperalgesia and mechanical allodynia, but not thermal hyperalgesia, were significantly induced. In the first footpad, normal epidermal innervations were verified by the protein gene product 9.5 (PGP9.5)- and growth-associated protein 43 (GAP43)-immunoreactive (IR) intraepidermal nerve fibers (IENFs) densities. Furthermore, the rapid increases of phospho-PKCg- and phosphomTOR-IR subepidermal nerve fibers (SENFs) areas were distinct gathered from the results of PGP9.5-, GAP43-, and neurofilament 200 (NF200)-IR SENFs areas. The efficacy of PKC inhibitor (GF 109203X) or mTOR complex 1 inhibitor (rapamycin) for attenuating mechanical hyperalgesia and mechanical allodynia by intraplantar injection was dose-dependent. CONCLUSIONS From results obtained in this study, we strongly recommend that the intact SENFs persistently increase PKCg activation and mTOR-dependent PKCg synthesis participate in the initiation and maintenance of mechanical hypersensitivity in spared nerve injury, which represents as a novel insight into the therapeutic strategy of pain in the periphery.
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Affiliation(s)
- Miau-Hwa Ko
- Department of Anatomy, College of Medicine, China Medical University, Taichung, Taiwan
| | - Ming-Ling Yang
- Department of Anatomy, School of Medicine, Chung Shan Medical University, Taichung, Taiwan
- Department of Medical Education, Chung Shan Medical University Hospital, Taichung, Taiwan
| | - Su-Chung Youn
- Department of Anatomy, School of Medicine, Chung Shan Medical University, Taichung, Taiwan
- Department of Medical Education, Chung Shan Medical University Hospital, Taichung, Taiwan
| | - Chyn-Tair Lan
- Department of Anatomy, School of Medicine, Chung Shan Medical University, Taichung, Taiwan
- Department of Medical Education, Chung Shan Medical University Hospital, Taichung, Taiwan
- Chyn-Tair Lan, Department of Anatomy, School of Medicine, Chung Shan Medical University, No. 110, Jian-Guo N. R., Sec. 1, Taichung 40201, Taiwan. To-Jung Tseng, Department of Anatomy, School of Medicine, Chung Shan Medical University, No. 110, Jian-Guo N. R., Sec. 1, Taichung 40201, Taiwan.
| | - To-Jung Tseng
- Department of Anatomy, School of Medicine, Chung Shan Medical University, Taichung, Taiwan
- Department of Medical Education, Chung Shan Medical University Hospital, Taichung, Taiwan
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He WY, Zhang B, Xiong QM, Yang CX, Zhao WC, He J, Zhou J, Wang HB. Intrathecal administration of rapamycin inhibits the phosphorylation of DRG Nav1.8 and attenuates STZ-induced painful diabetic neuropathy in rats. Neurosci Lett 2016; 619:21-8. [DOI: 10.1016/j.neulet.2016.02.064] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 02/27/2016] [Accepted: 02/29/2016] [Indexed: 01/19/2023]
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Abstract
Chronic pain is a major clinical problem that is poorly treated with available therapeutics. Adenosine monophosphate-activated protein kinase (AMPK) has recently emerged as a novel target for the treatment of pain with the exciting potential for disease modification. AMPK activators inhibit signaling pathways that are known to promote changes in the function and phenotype of peripheral nociceptive neurons and promote chronic pain. AMPK activators also reduce the excitability of these cells suggesting that AMPK activators may be efficacious for the treatment of chronic pain disorders, like neuropathic pain, where changes in the excitability of nociceptors is thought to be an underlying cause. In agreement with this, AMPK activators have now been shown to alleviate pain in a broad variety of preclinical pain models indicating that this mechanism might be engaged for the treatment of many types of pain in the clinic. A key feature of the effect of AMPK activators in these models is that they can lead to a long-lasting reversal of pain hypersensitivity even long after treatment cessation, indicative of disease modification. Here, we review the evidence supporting AMPK as a novel pain target pointing out opportunities for further discovery that are likely to have an impact on drug discovery efforts centered around potent and specific allosteric activators of AMPK for chronic pain treatment.
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Khoutorsky A, Bonin RP, Sorge RE, Gkogkas CG, Pawlowski SA, Jafarnejad SM, Pitcher MH, Alain T, Perez-Sanchez J, Salter EW, Martin L, Ribeiro-da-Silva A, De Koninck Y, Cervero F, Mogil JS, Sonenberg N. Translational control of nociception via 4E-binding protein 1. eLife 2015; 4. [PMID: 26678009 PMCID: PMC4695384 DOI: 10.7554/elife.12002] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 11/01/2015] [Indexed: 12/31/2022] Open
Abstract
Activation of the mechanistic/mammalian target of rapamycin (mTOR) kinase in models of acute and chronic pain is strongly implicated in mediating enhanced translation and hyperalgesia. However, the molecular mechanisms by which mTOR regulates nociception remain unclear. Here we show that deletion of the eukaryotic initiation factor 4E-binding protein 1 (4E-BP1), a major mTOR downstream effector, which represses eIF4E activity and cap-dependent translation, leads to mechanical, but not thermal pain hypersensitivity. Mice lacking 4E-BP1 exhibit enhanced spinal cord expression of neuroligin 1, a cell-adhesion postsynaptic protein regulating excitatory synapse function, and show increased excitatory synaptic input into spinal neurons, and a lowered threshold for induction of synaptic potentiation. Pharmacological inhibition of eIF4E or genetic reduction of neuroligin 1 levels normalizes the increased excitatory synaptic activity and reverses mechanical hypersensitivity. Thus, translational control by 4E-BP1 downstream of mTOR effects the expression of neuroligin 1 and excitatory synaptic transmission in the spinal cord, and thereby contributes to enhanced mechanical nociception. DOI:http://dx.doi.org/10.7554/eLife.12002.001 Despite the unpleasant feeling it causes, pain is necessary for survival as it helps individuals to avoid objects, environments and situations that cause damage to their body. However, millions of people experience long-lasting “chronic” pain, or are hypersensitive to pain. There are few treatments available for these conditions, but these treatments do not work well for the majority of patients, and can have serious side effects. To develop new treatments, researchers must first better understand how chronic pain develops. Pain is transmitted to the brain in the form of electrical signals “fired” along nerve fibers. Different nerves transmit information about different types of pain: for example, pain caused by a sharp object pressed against the skin activates a different set of neurons to those activated when touching something dangerously hot. Studies in mice have suggested that a protein called mTOR that is found inside neurons is important for them to fire pain signals. However, it is not clear exactly how mTOR contributes to pain signaling, although it is known to affect the activities of several other proteins in neurons. One protein that mTOR affects the activity of is called 4E-BP1. Now, Khoutorsky, Bonin, Sorge et al. show that mice that lack 4E-BP1 behave in ways that suggest they are hypersensitive to poking or pinching sensations. However, the mice did not show hypersensitivity when they touched a hot surface. Further investigation revealed that the neurons in the spinal cord of mice that lack 4E-BP1 produce abnormally high amounts of a molecule called neuroligin 1, which makes the neurons more likely to fire and thus signal pain. Khoutorsky, Bonin, Sorge et al. found that treating mice that lack 4E-BP1 with a compound that reduces neuroligin 1 production causes their neurons to fire more normally. This also reduces the animals’ apparent signs of hypersensitivity to pressure on their skin. It will be important in future studies to identify additional targets of 4E-BP1 in the spinal cord that could contribute to increased mechanical sensation, and also to study the role of 4E-BP1 in peripheral nerves. DOI:http://dx.doi.org/10.7554/eLife.12002.002
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Affiliation(s)
- Arkady Khoutorsky
- Department of Biochemistry, McGill University, Montréal, Canada.,Rosalind and Morris Goodman Cancer Research Centre, McGill University, Montréal, Canada
| | - Robert P Bonin
- Unité de neurosciences cellulaires et moléculaire, Institut universitaire en santé mentale de Québec, Québec, Canada
| | - Robert E Sorge
- Department of Psychology, McGill University, Montréal, Canada.,Alan Edwards Centre for Research on Pain, McGill University, Montréal, Canada
| | - Christos G Gkogkas
- Department of Biochemistry, McGill University, Montréal, Canada.,Centre for Integrative Physiology and The Patrick Wild Centre, University of Edinburgh, Edinburgh, United Kingdom
| | - Sophie Anne Pawlowski
- Alan Edwards Centre for Research on Pain, McGill University, Montréal, Canada.,Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada
| | - Seyed Mehdi Jafarnejad
- Department of Biochemistry, McGill University, Montréal, Canada.,Rosalind and Morris Goodman Cancer Research Centre, McGill University, Montréal, Canada
| | - Mark H Pitcher
- National Center for Complementary and Alternative Medicine, National Institutes of Health, Porter Neuroscience Research Center, Maryland, United States
| | - Tommy Alain
- Department of Biochemistry, McGill University, Montréal, Canada.,Rosalind and Morris Goodman Cancer Research Centre, McGill University, Montréal, Canada
| | - Jimena Perez-Sanchez
- Unité de neurosciences cellulaires et moléculaire, Institut universitaire en santé mentale de Québec, Québec, Canada
| | - Eric W Salter
- Unité de neurosciences cellulaires et moléculaire, Institut universitaire en santé mentale de Québec, Québec, Canada
| | - Loren Martin
- Department of Psychology, McGill University, Montréal, Canada.,Alan Edwards Centre for Research on Pain, McGill University, Montréal, Canada
| | - Alfredo Ribeiro-da-Silva
- Alan Edwards Centre for Research on Pain, McGill University, Montréal, Canada.,Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada
| | - Yves De Koninck
- Unité de neurosciences cellulaires et moléculaire, Institut universitaire en santé mentale de Québec, Québec, Canada.,Alan Edwards Centre for Research on Pain, McGill University, Montréal, Canada.,Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada.,Department of Psychiatry and Neuroscience, Université Laval, Québec, Canada
| | - Fernando Cervero
- Alan Edwards Centre for Research on Pain, McGill University, Montréal, Canada.,Anesthesia Research Unit, McGill University, Montreal, Canada
| | - Jeffrey S Mogil
- Department of Psychology, McGill University, Montréal, Canada.,Alan Edwards Centre for Research on Pain, McGill University, Montréal, Canada
| | - Nahum Sonenberg
- Department of Biochemistry, McGill University, Montréal, Canada.,Rosalind and Morris Goodman Cancer Research Centre, McGill University, Montréal, Canada
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Izumi Y, Sasaki M, Hashimoto S, Sawa T, Amaya F. mTOR signaling controls VGLUT2 expression to maintain pain hypersensitivity after tissue injury. Neuroscience 2015; 308:169-79. [DOI: 10.1016/j.neuroscience.2015.09.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 08/16/2015] [Accepted: 09/03/2015] [Indexed: 01/09/2023]
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Lutz BM, Nia S, Xiong M, Tao YX, Bekker A. mTOR, a new potential target for chronic pain and opioid-induced tolerance and hyperalgesia. Mol Pain 2015; 11:32. [PMID: 26024835 PMCID: PMC4455918 DOI: 10.1186/s12990-015-0030-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 05/21/2015] [Indexed: 01/25/2023] Open
Abstract
Chronic pain is a major public health problem with limited treatment options. Opioids remain a routine treatment for chronic pain, but extended exposure to opioid therapy can produce opioid tolerance and hyperalgesia. Although the mechanisms underlying chronic pain, opioid-induced tolerance, and opioid-induced hyperalgesia remain to be uncovered, mammalian target of rapamycin (mTOR) is involved in these disorders. The mTOR complex 1 and its triggered protein translation are required for the initiation and maintenance of chronic pain (including cancer pain) and opioid-induced tolerance/hyperalgesia. Given that mTOR inhibitors are FDA-approved drugs and an mTOR inhibitor is approved for the treatment of several cancers, these findings suggest that mTOR inhibitors will likely have multiple clinical benefits, including anticancer, antinociception/anti-cancer pain, and antitolerance/hyperalgesia. This paper compares the role of mTOR complex 1 in chronic pain, opioid-induced tolerance, and opioid-induced hyperalgesia.
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Affiliation(s)
- Brianna Marie Lutz
- Rutgers Graduate School of Biomedical Sciences, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA.,Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA
| | - Sam Nia
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA
| | - Ming Xiong
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA
| | - Yuan-Xiang Tao
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA.
| | - Alex Bekker
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA.
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39
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Li G, Lu X, Zhang S, Zhou Q, Zhang L. mTOR and Erk1/2 Signaling in the Cerebrospinal Fluid-Contacting Nucleus is Involved in Neuropathic Pain. Neurochem Res 2015; 40:1053-62. [DOI: 10.1007/s11064-015-1564-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Revised: 03/24/2015] [Accepted: 03/26/2015] [Indexed: 12/13/2022]
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40
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Huang SY, Sung CS, Chen WF, Chen CH, Feng CW, Yang SN, Hung HC, Chen NF, Lin PR, Chen SC, Wang HMD, Chu TH, Tai MH, Wen ZH. Involvement of phosphatase and tensin homolog deleted from chromosome 10 in rodent model of neuropathic pain. J Neuroinflammation 2015; 12:59. [PMID: 25889774 PMCID: PMC4386079 DOI: 10.1186/s12974-015-0280-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 03/07/2015] [Indexed: 12/30/2022] Open
Abstract
Background Many cancer research studies have extensively examined the phosphatase and tensin homolog deleted from chromosome 10 (PTEN) pathway. There are only few reports that suggest that PTEN might affect pain; however, there is still a lack of evidence to show the role of PTEN for modulating pain. Here, we report a role for PTEN in a rodent model of neuropathic pain. Results We found that chronic constriction injury (CCI) surgery in rats could elicit downregulation of spinal PTEN as well as upregulation of phosphorylated PTEN (phospho-PTEN) and phosphorylated mammalian target of rapamycin (phospho-mTOR). After examining such changes in endogenous PTEN in neuropathic rats, we explored the effects of modulating the spinal PTEN pathway on nociceptive behaviors. The normal rats exhibited mechanical allodynia after intrathecal (i.t.) injection of adenovirus-mediated PTEN antisense oligonucleotide (Ad-antisense PTEN). These data indicate the importance of downregulation of spinal PTEN for nociception. Moreover, upregulation of spinal PTEN by i.t. adenovirus-mediated PTEN (Ad-PTEN) significantly prevented CCI-induced development of nociceptive sensitization, thermal hyperalgesia, mechanical allodynia, cold allodynia, and weight-bearing deficits in neuropathic rats. Furthermore, upregulation of spinal PTEN by i.t. Ad-PTEN significantly attenuated CCI-induced microglia and astrocyte activation, upregulation of tumor necrosis factor-α (TNF-α) and phospho-mTOR, and downregulation of PTEN in neuropathic rats 14 days post injury. Conclusions These findings demonstrate that PTEN plays a key, beneficial role in a rodent model of neuropathic pain.
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Affiliation(s)
- Shi-Ying Huang
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, No. 70, Lienhai Road, Kaohsiung, 80424, Taiwan. .,Center for Neuroscience, National Sun Yat-sen University, No. 70, Lienhai Road, Kaohsiung, 80424, Taiwan.
| | - Chun-Sung Sung
- Department of Anesthesiology, Taipei Veterans General Hospital, No. 201, Section 2, Shipai Road, Taipei, 11217, Taiwan. .,School of Medicine, National Yang-Ming University, No. 155, Section 2, Linong Street, Taipei, 11221, Taiwan.
| | - Wu-Fu Chen
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, No. 70, Lienhai Road, Kaohsiung, 80424, Taiwan. .,Department of Neurosurgery, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, No. 123, DAPI Road, Kaohsiung, 83301, Taiwan. .,Department of Neurosurgery, Xiamen Chang Gung Memorial Hospital, No. 123, Xiafei Road, Fujian, 361026, China.
| | - Chun-Hong Chen
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, No. 70, Lienhai Road, Kaohsiung, 80424, Taiwan. .,Doctoral Degree Program in Marine Biotechnology, National Sun Yat-sen University and Academia Sinica, No. 70, Lienhai Road, Kaohsiung, 80424, Taiwan.
| | - Chien-Wei Feng
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, No. 70, Lienhai Road, Kaohsiung, 80424, Taiwan. .,Doctoral Degree Program in Marine Biotechnology, National Sun Yat-sen University and Academia Sinica, No. 70, Lienhai Road, Kaohsiung, 80424, Taiwan.
| | - San-Nan Yang
- School of Medicine, College of Medicine and Department of Pediatrics, E-DA Hospital, I-Shou University, No. 1, Yida Road, Kaohsiung, 82445, Taiwan.
| | - Han-Chun Hung
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, No. 70, Lienhai Road, Kaohsiung, 80424, Taiwan. .,Doctoral Degree Program in Marine Biotechnology, National Sun Yat-sen University and Academia Sinica, No. 70, Lienhai Road, Kaohsiung, 80424, Taiwan.
| | - Nan-Fu Chen
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, No. 70, Lienhai Road, Kaohsiung, 80424, Taiwan. .,Division of Neurosurgery, Department of Surgery, Kaohsiung Armed Forces General Hospital, No. 2, Zhongzheng 1st Road, Kaohsiung, 80284, Taiwan.
| | - Pey-Ru Lin
- Institute of Biomedical Sciences, National Sun Yat-sen University, #70 Lienhai Road, Kaohsiung, 80424, Taiwan.
| | - San-Cher Chen
- Center for Neuroscience, National Sun Yat-sen University, No. 70, Lienhai Road, Kaohsiung, 80424, Taiwan. .,Institute of Biomedical Sciences, National Sun Yat-sen University, #70 Lienhai Road, Kaohsiung, 80424, Taiwan.
| | - Hui-Min David Wang
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, No. 70, Lienhai Road, Kaohsiung, 80424, Taiwan. .,Department of Fragrance and Cosmetic Science, Kaohsiung Medical University, No. 100, Shiquan 1st Road, Kaohsiung, 80708, Taiwan. .,Graduate Institute of Natural Products, Kaohsiung Medical University, No. 100, Shiquan 1st Road, Kaohsiung, 80708, Taiwan. .,Center for Stem Cell Research, Kaohsiung Medical University, No. 100, Shiquan 1st Road, Kaohsiung, 80708, Taiwan.
| | - Tian-Huei Chu
- Institute of Biomedical Sciences, National Sun Yat-sen University, #70 Lienhai Road, Kaohsiung, 80424, Taiwan.
| | - Ming-Hong Tai
- Center for Neuroscience, National Sun Yat-sen University, No. 70, Lienhai Road, Kaohsiung, 80424, Taiwan. .,Institute of Biomedical Sciences, National Sun Yat-sen University, #70 Lienhai Road, Kaohsiung, 80424, Taiwan. .,Department of Biological Sciences, National Sun Yat-sen University, No. 70, Lienhai Road, Kaohsiung, 80424, Taiwan.
| | - Zhi-Hong Wen
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, No. 70, Lienhai Road, Kaohsiung, 80424, Taiwan. .,Doctoral Degree Program in Marine Biotechnology, National Sun Yat-sen University and Academia Sinica, No. 70, Lienhai Road, Kaohsiung, 80424, Taiwan. .,Marine Biomedical Laboratory and Center for Translational Biopharmaceuticals, Department of Marine Biotechnology and Resources, National Sun Yat-sen University, No. 70, Lienhai Road, Kaohsiung, 80424, Taiwan.
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Melemedjian OK, Khoutorsky A. Translational control of chronic pain. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 131:185-213. [PMID: 25744674 DOI: 10.1016/bs.pmbts.2014.11.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Pain is a crucial physiological response to injury and pathologies. The development and maintenance of pain requires the expression of novel genes. The expression of such genes occurs in highly regulated and orchestrated manner where protein translation provides an exquisite temporal and spatial fidelity within the axons and dendrites of neurons. Signaling pathways that regulate local translation are activated by cytokines, neurotrophic factors, or neurotransmitters, which are released either due to tissue damage or neuronal activity. In recent years, the ERK and mTOR pathways have been demonstrated to be central in regulating local translation in neurons of both the peripheral and central nervous systems in diverse models of chronic pain. The ERK and mTOR pathways converge onto the cap-dependent translational machinery that regulates genes essential for the development of nociceptive sensitization. Moreover, inhibition of these pathways has proved to be effective in normalizing the biochemical changes and the associated pain in various preclinical models.
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Affiliation(s)
- Ohannes K Melemedjian
- Department of Neural and Pain Sciences, School of Dentistry, University of Maryland, Baltimore, Maryland, USA.
| | - Arkady Khoutorsky
- Department of Biochemistry, Rosalind and Morris Goodman Cancer Research Centre, McGill University, Montréal, Quebec, Canada
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Xu JT, Sun L, Lutz BM, Bekker A, Tao YX. Intrathecal rapamycin attenuates morphine-induced analgesic tolerance and hyperalgesia in rats with neuropathic pain. TRANSLATIONAL PERIOPERATIVE AND PAIN MEDICINE 2015; 2:27-34. [PMID: 26339682 PMCID: PMC4556423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Repeated and long-term administration of opioids is often accompanied by the initiation of opioid-induced analgesic tolerance and hyperalgesia in chronic pain patients. Our previous studies showed that repeated intrathecal morphine injection activated the mammalian target of rapamycin complex 1 (mTORC1) in spinal dorsal horn neurons and that blocking this activation prevented the initiation of morphine-induced tolerance and hyperalgesia in healthy rats. However, whether spinal mTORC1 is required for morphine-induced tolerance and hyperalgesia under neuropathic pain conditions remains elusive. We here observed the effect of intrathecal infusion of rapamycin, a specific mTORC1 inhibitor, on morphine-induced tolerance and hyperalgesia in a neuropathic pain model in rats induced by the fifth lumbar spinal nerve ligation (SNL). Continuous intrathecal infusion of morphine for one week starting on day 8 post-SNL led to morphine tolerance demonstrated by morphine-induced reduction in maximal possible analgesic effect (MPAE) to tail heat stimuli and ipsilateral paw withdrawal threshold (PWT) to mechanical stimuli in SNL rats. Such reduction was attenuated by co-infusion of rapamycin. Co-infusion of rapamycin also blocked morphine tolerance demonstrated by attenuation of morphine-induced reduction in MPAE in sham rats and morphine-induced hyperalgesia demonstrated by the reverse of morphine-induced reduction in PWT on both sides of sham rats and on the contralateral side of SNL rats. The results suggest that mTORC1 inhibitors could serve as promising medications for use as adjuvants with opioids in clinical neuropathic pain management.
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Affiliation(s)
- Ji-Tian Xu
- Department of Physiology & Neurobiology, College of Basic Medicine, Zhengzhou University, Zhengzhou, Henan Province 450001, People’s Republic of China
| | - Linlin Sun
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
| | - Brianna Marie Lutz
- Rutgers Graduate School of Biomedical Sciences, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
| | - Alex Bekker
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
| | - Yuan-Xiang Tao
- Department of Physiology & Neurobiology, College of Basic Medicine, Zhengzhou University, Zhengzhou, Henan Province 450001, People’s Republic of China
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
- Departments of Cell Biology & Molecular Medicine, Neurology & Neuroscience, and Physiology & Pharmacology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
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mTOR kinase: a possible pharmacological target in the management of chronic pain. BIOMED RESEARCH INTERNATIONAL 2015; 2015:394257. [PMID: 25685786 PMCID: PMC4313067 DOI: 10.1155/2015/394257] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 09/12/2014] [Indexed: 12/29/2022]
Abstract
Chronic pain represents a major public health problem worldwide. Current pharmacological treatments for chronic pain syndromes, including neuropathic pain, are only partially effective, with significant pain relief achieved in 40-60% of patients. Recent studies suggest that the mammalian target of rapamycin (mTOR) kinase and downstream effectors may be implicated in the development of chronic inflammatory, neuropathic, and cancer pain. The expression and activity of mTOR have been detected in peripheral and central regions involved in pain transmission. mTOR immunoreactivity was found in primary sensory axons, in dorsal root ganglia (DRG), and in dorsal horn neurons. This kinase is a master regulator of protein synthesis, and it is critically involved in the regulation of several neuronal functions, including the synaptic plasticity that is a major mechanism leading to the development of chronic pain. Enhanced activation of this pathway is present in different experimental models of chronic pain. Consistently, pharmacological inhibition of the kinase activity turned out to have significant antinociceptive effects in several experimental models of inflammatory and neuropathic pain. We will review the main evidence from animal and human studies supporting the hypothesis that mTOR may be a novel pharmacological target for the management of chronic pain.
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Hirsch S, Dickenson A, Corradini L. Anesthesia influences neuronal activity and drug effectiveness in neuropathic rats. Pain 2014; 155:2583-2590. [DOI: 10.1016/j.pain.2014.09.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 09/16/2014] [Accepted: 09/16/2014] [Indexed: 01/16/2023]
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45
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Cui J, He W, Yi B, Zhao H, Lu K, Ruan H, Ma D. mTOR pathway is involved in ADP-evoked astrocyte activation and ATP release in the spinal dorsal horn in a rat neuropathic pain model. Neuroscience 2014; 275:395-403. [PMID: 24976516 DOI: 10.1016/j.neuroscience.2014.06.030] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 06/10/2014] [Accepted: 06/13/2014] [Indexed: 01/13/2023]
Abstract
BACKGROUND ATP/ADP-evoked spinal astrocyte activation plays a vital role in the development of neuropathic pain. We aim to investigate the role of mammalian target of rapamycin (mTOR) pathway on the spinal astrocyte activation in the neuropathic pain development in rats. METHODS Sprague Dawley (SD) rats were subjected to chronic constriction of the sciatic nerve (CCI). Rapamycin or ADP was intrathecally injected daily to explore their effects on spinal astrocyte activation and pain development. Expression of glial fibrillary acidic protein (GFAP) and mTOR in the spinal dorsal horn was assessed by immunohistochemistry. Von Frey hairs and Hargreaves paw withdrawal test were conducted to evaluate mechanical allodynia and thermal sensitivity, respectively. Firefly luciferase ATP assay was used to assess the change of ATP level in cerebrospinal fluid (CSF) and medium of cultured astrocytes. RESULTS GFAP expression was enhanced in the ipsilateral spinal dorsal horn from day 3 after surgery. GFAP and mTOR expression in the rat spinal dorsal horn on post-surgical day 14 was enhanced by daily intrathecal injection of ADP, which was inhibited by rapamycin. Rapamycin decreased lower mechanical pain threshold and the thermal withdrawal latency. Intrathecal injection of ADP enhanced the ATP release, which was partially inhibited by rapamycin. Study of cultured astrocytes indicated that ATP could be released from astrocytes. CONCLUSION Our data demonstrated that ADP enhanced neuropathic pain in CCI rats, which was inhibited by rapamycin. This study indicates that targeting mTOR pathway could serve as a novel therapeutic strategy in neuropathic pain management.
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Affiliation(s)
- J Cui
- Department of Anaesthesiology, Southwest Hospital, Third Military Medical University, Chongqing 400038, China
| | - W He
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, College of Basic Medical Sciences, Third Military Medical University, Chongqing 400038, China
| | - B Yi
- Department of Anaesthesiology, Southwest Hospital, Third Military Medical University, Chongqing 400038, China
| | - H Zhao
- Section of Anaesthetics, Pain Medicine and Intensive Care, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Chelsea & Westminster Hospital, London, UK
| | - K Lu
- Department of Anaesthesiology, Southwest Hospital, Third Military Medical University, Chongqing 400038, China.
| | - H Ruan
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, College of Basic Medical Sciences, Third Military Medical University, Chongqing 400038, China.
| | - D Ma
- Section of Anaesthetics, Pain Medicine and Intensive Care, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Chelsea & Westminster Hospital, London, UK
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Hua C, Zehou O, Ducassou S, Minard-Colin V, Hamel-Teillac D, Wolkenstein P, Valeyrie-Allanore L. Sirolimus improves pain in NF1 patients with severe plexiform neurofibromas. Pediatrics 2014; 133:e1792-7. [PMID: 24864177 DOI: 10.1542/peds.2013-1224] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Plexiform neurofibromas (PNs) are common and potentially debilitating complications of neurofibromatosis 1 (NF1). These benign nerve-sheath tumors are associated with significant pain and morbidity because they compress vital structures. The mammalian target of rapamycin (mTOR) pathway is a major mediator involved in tumor growth in NF1. We present 3 cases of patients with NF1, aged 8, 16, and 17 years, followed for inoperable and symptomatic PNs; patients received sirolimus for life-threatening and painful neurofibromas after multidisciplinary consultation. Epidemiologic, clinical, and radiologic data were retrospectively collected. The volume of PNs did not differ between baseline and 12-month follow-up and pain was alleviated, with withdrawal of analgesics in 2 cases at 6 months, and significantly decreased for the third case. Sirolimus for inoperable symptomatic PNs in patients with NF1 permitted stabilization of mass and produced unpredictable and important alleviation of pain in all cases with good tolerance. This treatment was proposed in extreme cases, in absence of therapeutic alternatives, after multidisciplinary consensus. The mTOR pathway may be both a major mediator of NF1 tumor growth and regulator of nociceptor sensitivity. mTOR inhibitors clinically used as anticancer and immunosuppressant drugs could be a potential treatment of chronic pain.
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Affiliation(s)
- Camille Hua
- AP-HP, Hôpital Henri-Mondor, Service de Dermatologie, Centre de référence des Neurofibromatoses, Créteil, France
| | - Ouidad Zehou
- AP-HP, Hôpital Henri-Mondor, Service de Dermatologie, Centre de référence des Neurofibromatoses, Créteil, France
| | - Stéphane Ducassou
- CHU Bordeaux, GH Pellegrin, Service d'Onco-Hématologie Pédiatrique, Bordeaux, France
| | - Véronique Minard-Colin
- Institut Gustave Roussy, Département de Cancérologie de l'Enfant et de l'Adolescent, Villejuif, France
| | | | - Pierre Wolkenstein
- AP-HP, Hôpital Henri-Mondor, Service de Dermatologie, Centre de référence des Neurofibromatoses, Créteil, France
- LIC EA 4393, Hôpital Henri Mondor, Assistance Publique Hôpitaux de Paris, Université Paris-Est Créteil, Créteil, France
| | - Laurence Valeyrie-Allanore
- AP-HP, Hôpital Henri-Mondor, Service de Dermatologie, Centre de référence des Neurofibromatoses, Créteil, France
- LIC EA 4393, Hôpital Henri Mondor, Assistance Publique Hôpitaux de Paris, Université Paris-Est Créteil, Créteil, France
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Kjell J, Codeluppi S, Josephson A, Abrams MB. Spatial and cellular characterization of mTORC1 activation after spinal cord injury reveals biphasic increase mainly attributed to microglia/macrophages. Brain Pathol 2014; 24:557-67. [PMID: 24576152 PMCID: PMC4347463 DOI: 10.1111/bpa.12135] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Accepted: 02/17/2014] [Indexed: 01/07/2023] Open
Abstract
Mechanistic target of rapamycin complex 1 (mTORC1) is an intracellular kinase complex that regulates energy homeostasis and transcription. Modulation of mTORC1 has proven beneficial in experimental spinal cord injury, making this molecular target a candidate for therapeutic intervention in spinal cord injury. However, both inactivation and activation of mTORC1 have been reported beneficial for recovery. To obtain a more complete picture of mTORC1 activity, we aimed to characterize the spatiotemporal activation pattern of mTORC1 and identify activation in particular cell types after contusion spinal cord injury in rats. To be able to provide a spatial characterization of mTORC1 activation, we monitored activation of downstream target S6. We found robust mTORC1 activation both at the site of injury and in spinal segments rostral and caudal to the injury. There was constitutive mTORC1 activation in neurons that was biphasically reduced caudally after injury. We found biphasic mTORC1 activation in glial cells, primarily activated microglia/macrophages. Furthermore, we found mTORC1 activation in proliferating cells, suggesting this may be a function affected by mTORC1 modulation. Our results reveal potential windows of opportunity for therapeutic interference with mTORC1 signaling and immune cells as targets for inhibition of mTORC1 in spinal cord injury.
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Affiliation(s)
- Jacob Kjell
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
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48
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Iannitti T, Kerr BJ, Taylor BK. Mechanisms and pharmacology of neuropathic pain in multiple sclerosis. Curr Top Behav Neurosci 2014; 20:75-97. [PMID: 24590824 PMCID: PMC4464806 DOI: 10.1007/7854_2014_288] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The neuropathic pain of multiple sclerosis is quite prevalent and severely impacts quality of life. A few randomized, placebo-controlled, blinded clinical trials suggest that cannabis- and anticonvulsant-based treatments provide partial pain relief, but at the expense of adverse events. An even smaller, but emerging, number of translational studies are using rodent models of experimental autoimmune encephalomyelitis (EAE), which exhibit pain-like behaviors resembling those of Multiple sclerosis (MS) patients. These studies not only support the possible effectiveness of anticonvulsants, but also compel further clinical trials with serotonin-norepinephrine reuptake inhibitors, the immunosuppressant drug rapamycin, or drugs which interfere with glutamatergic neurotransmission. Future behavioral studies in EAE models are essential toward a new pharmacotherapy of multiple sclerosis pain.
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Affiliation(s)
- T Iannitti
- Department of Physiology, School of Medicine, University of Kentucky Medical Center, Lexington, KY, 40536-0298, USA
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49
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Abstract
The number of approved new molecular entity drugs has been decreasing as the pharmaceutical company investment in research and development is increasing. As we face this painful crisis, called an innovation gap, there is increasing awareness that development of new uses of existing drugs may be a powerful tool to help overcome this obstacle because it takes too long, costs too much and can be risky to release drugs developed de novo. Consequently, drug repositioning is emerging in different therapeutic areas, including the pain research area. Worldwide, pain is the main reason for seeking healthcare, and pain relief represents an unmet global clinical need. Therefore, development of analgesics with better efficacy, safety and cost effectiveness is of paramount importance. Despite the remarkable advancement in research on cellular and molecular mechanisms underlying pain pathophysiology over the past three decades, target-based therapeutic opportunities have not been pursued to the same extent. Phenotypic screening remains a more powerful tool for drug development than target-based screening so far. It sounds somewhat heretical, but some multi-action drugs, rather than very selective ones, have been developed intentionally. In the present review, we first critically discuss the utility of drug repositioning for analgesic drug development and then show examples of 'old' drugs that have been successfully repositioned or that are under investigation for their analgesic actions. We conclude that drug repositioning should be more strongly encouraged to help build a bridge between basic research and pain relief worldwide.
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Affiliation(s)
- Leandro Francisco Silva Bastos
- Laboratório de Imunofarmacologia, sala O4-202, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Avenida Antônio Carlos 6627, Pampulha, Belo Horizonte, CEP 31.270-901, Brazil,
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50
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Jiang F, Hua LM, Jiao YL, Ye P, Fu J, Cheng ZJ, Ding G, Ji YH. Activation of mammalian target of rapamycin contributes to pain nociception induced in rats by BmK I, a sodium channel-specific modulator. Neurosci Bull 2013; 30:21-32. [PMID: 24132796 DOI: 10.1007/s12264-013-1377-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2012] [Accepted: 04/15/2013] [Indexed: 02/02/2023] Open
Abstract
The mammalian target of rapamycin (mTOR) pathway is essential for maintenance of the sensitivity of certain adult sensory neurons. Here, we investigated whether the mTOR cascade is involved in scorpion envenomation-induced pain hypersensitivity in rats. The results showed that intraplantar injection of a neurotoxin from Buthus martensii Karsch, BmK I (10 μg), induced the activation of mTOR, as well as its downstream molecules p70 ribosomal S6 protein kinase (p70 S6K) and eukaryotic initiation factor 4E-binding protein 1 (4E-BP1), in lumbar 5-6 dorsal root ganglia neurons on both sides in rats. The activation peaked at 2 h and recovered 1 day after injection. Compared with the control group, the ratios of p-mTOR/p-p70 S6K/p-4EBP1 in three types of neurons changed significantly. The cell typology of p-mTOR/p-p70 S6K/p-4E-BP1 immuno-reactive neurons also changed. Intrathecal administration of deforolimus, a specific inhibitor of mTOR, attenuated BmK I-induced pain responses (spontaneous flinching, paroxysmal pain-like behavior, and mechanical hypersensitivity). Together, these results imply that the mTOR signaling pathway is mobilized by and contributes to experimental scorpion sting-induced pain.
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Affiliation(s)
- Feng Jiang
- Xinhua Hospital (Chongming) Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai Chongming Xinhua Translational Medical Institute for Cancer Pain, Shanghai, 202150, China
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