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Abstract
Neuropathic pain is a debilitating form of pain arising from injury or disease of the nervous system that affects millions of people worldwide. Despite its prevalence, the underlying mechanisms of neuropathic pain are still not fully understood. Dendritic spines are small protrusions on the surface of neurons that play an important role in synaptic transmission. Recent studies have shown that dendritic spines reorganize in the superficial and deeper laminae of the spinal cord dorsal horn with the development of neuropathic pain in multiple models of disease or injury. Given the importance of dendritic spines in synaptic transmission, it is possible that studying dendritic spines could lead to new therapeutic approaches for managing intractable pain. In this review article, we highlight the emergent role of dendritic spines in neuropathic pain, as well as discuss the potential for studying dendritic spines for the development of new therapeutics.
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Affiliation(s)
- Curtis A Benson
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, CT, USA
- Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, CT, USA
| | - Jared F King
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, CT, USA
- Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, CT, USA
| | - Marike L Reimer
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, CT, USA
- Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, CT, USA
| | - Sierra D Kauer
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, CT, USA
- Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, CT, USA
| | - Stephen G Waxman
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, CT, USA
- Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, CT, USA
| | - Andrew M Tan
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, CT, USA
- Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, CT, USA
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2
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Allahham A, Rowe G, Stevenson A, Fear MW, Vallence AM, Wood FM. The impact of burn injury on the central nervous system. BURNS & TRAUMA 2024; 12:tkad037. [PMID: 38312739 PMCID: PMC10835674 DOI: 10.1093/burnst/tkad037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 05/31/2023] [Accepted: 06/21/2023] [Indexed: 02/06/2024]
Abstract
Burn injuries can be devastating, with life-long impacts including an increased risk of hospitalization for a wide range of secondary morbidities. One area that remains not fully understood is the impact of burn trauma on the central nervous system (CNS). This review will outline the current findings on the physiological impact that burns have on the CNS and how this may contribute to the development of neural comorbidities including mental health conditions. This review highlights the damaging effects caused by burn injuries on the CNS, characterized by changes to metabolism, molecular damage to cells and their organelles, and disturbance to sensory, motor and cognitive functions in the CNS. This damage is likely initiated by the inflammatory response that accompanies burn injury, and it is often long-lasting. Treatments used to relieve the symptoms of damage to the CNS due to burn injury often target inflammatory pathways. However, there are non-invasive treatments for burn patients that target the functional and cognitive damage caused by the burn, including transcranial magnetic stimulation and virtual reality. Future research should focus on understanding the mechanisms that underpin the impact of a burn injury on the CNS, burn severity thresholds required to inflict damage to the CNS, and acute and long-term therapies to ameliorate deleterious CNS changes after a burn.
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Affiliation(s)
- Amira Allahham
- Burn injury research unit, School of Biomedical Sciences, University of Western Australia, 35 Stirling Highway, Crawley, Perth, WA 6009, Australia
- Fiona Wood Foundation, 11 Robin Warren Dr, Murdoch WA 6150, Australia
| | - Grant Rowe
- Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, 90 South Street, Murdoch, Perth 6150, Australia
| | - Andrew Stevenson
- Burn injury research unit, School of Biomedical Sciences, University of Western Australia, 35 Stirling Highway, Crawley, Perth, WA 6009, Australia
- Fiona Wood Foundation, 11 Robin Warren Dr, Murdoch WA 6150, Australia
| | - Mark W Fear
- Burn injury research unit, School of Biomedical Sciences, University of Western Australia, 35 Stirling Highway, Crawley, Perth, WA 6009, Australia
- Fiona Wood Foundation, 11 Robin Warren Dr, Murdoch WA 6150, Australia
| | - Ann-Maree Vallence
- Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, 90 South Street, Murdoch, Perth 6150, Australia
- Centre for Healthy Ageing, Health Futures Institute, Murdoch University, 90 South Street, Murdoch Perth 6150, Australia
- Burn Service of Western Australia, Fiona Stanley Hospital, MNH (B), Level 4, 102-118 Murdoch Drive, Murdoch, Perth, WA 6150, Australia
| | - Fiona M Wood
- Burn injury research unit, School of Biomedical Sciences, University of Western Australia, 35 Stirling Highway, Crawley, Perth, WA 6009, Australia
- Fiona Wood Foundation, 11 Robin Warren Dr, Murdoch WA 6150, Australia
- School of Psychology, College of Health and Education, Murdoch University, 90 South Street, Murdoch, Perth 6150, Australia
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3
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Zhang Z, Zheng H, Yu Q, Jing X. Understanding of Spinal Wide Dynamic Range Neurons and Their Modulation on Pathological Pain. J Pain Res 2024; 17:441-457. [PMID: 38318328 PMCID: PMC10840524 DOI: 10.2147/jpr.s446803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 01/12/2024] [Indexed: 02/07/2024] Open
Abstract
The spinal dorsal horn (SDH) transmits sensory information from the periphery to the brain. Wide dynamic range (WDR) neurons within this relay site play a critical role in modulating and integrating peripheral sensory inputs, as well as the process of central sensitization during pathological pain. This group of spinal multi-receptive neurons has attracted considerable attention in pain research due to their capabilities for encoding the location and intensity of nociception. Meanwhile, transmission, processing, and modulation of incoming afferent information in WDR neurons also establish the underlying basis for investigating the integration of acupuncture and pain signals. This review aims to provide a comprehensive examination of the distinctive features of WDR neurons and their involvement in pain. Specifically, we will examine the regulation of diverse supraspinal nuclei on these neurons and analyze their potential in elucidating the mechanisms of acupuncture analgesia.
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Affiliation(s)
- Zhiyun Zhang
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, People’s Republic of China
| | - Hao Zheng
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, People’s Republic of China
| | - Qingquan Yu
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, People’s Republic of China
| | - Xianghong Jing
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, People’s Republic of China
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Gunawardena DA, Stanley E, Issler-Fisher AC. Understanding Neural Factors in Burn-related Pruritus and Neuropathic Pain. J Burn Care Res 2023; 44:1182-1188. [PMID: 36794899 DOI: 10.1093/jbcr/irad021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Indexed: 02/17/2023]
Abstract
Post-burn pruritus and neuropathic pain significantly affect the quality of life of affected individuals in several domains including psychosocial well-being, sleep and general impairment in activities of daily living. Whilst neural mediators involved in itch in the non-burns setting have been well investigated, there remains a lacuna of literature examining the pathophysiological and histological changes unique to burn-related pruritus and neuropathic pain. The aim of our study was to conduct a scoping review into the neural factors that contribute to burn-related pruritus and neuropathic pain. A scoping review was conducted to provide an overview of the available evidence. The PubMed, EMBASE and Medline databases were searched for publications. Data regarding neural mediators implicated, population demographics, total body surface area (TBSA) affected and sex was extracted. In total, 11 studies were included in this review with a total of 881 patients. The most frequently investigated neurotransmitter was the Substance P (SP) neuropeptide which appeared in 36% of studies (n = 4), followed by calcitonin gene-related peptide (CGRP) in 27% of studies (n = 3). Post-burn pruritus and neuropathic pain are symptomatic experiences that are predicated upon a heterogeneous group of underlying mechanisms. What is clear from the literature, however, is that itch and pain may occur secondary to the influence of both neuropeptides, such as SP, and other neural mediators including Transient receptor protein channels. Of the articles included for review, they were characterized by small sample sizes and large differences in statistical methodology and reporting.
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Affiliation(s)
- Dulan A Gunawardena
- Concord Clinical School, University of Sydney, New South Wales, Australia
- Concord Repatriation General Hospital, Sydney, New South Wales, Australia
| | - Edward Stanley
- Concord Repatriation General Hospital, Sydney, New South Wales, Australia
| | - Andrea C Issler-Fisher
- Concord Clinical School, University of Sydney, New South Wales, Australia
- Concord Repatriation General Hospital, Sydney, New South Wales, Australia
- ANZAC Research Institute, Concord, New South Wales, Australia
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Wu Q, Cai C, Ying X, Zheng Y, Yu J, Gu X, Tu W, Lou X, Yang G, Li M, Jiang S. Electroacupuncture inhibits dendritic spine remodeling through the srGAP3-Rac1 signaling pathway in rats with SNL. Biol Res 2023; 56:26. [PMID: 37211600 DOI: 10.1186/s40659-023-00439-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 05/10/2023] [Indexed: 05/23/2023] Open
Abstract
Previous studies have shown that peripheral nerve injury can lead to abnormal dendritic spine remodeling in spinal dorsal horn neurons. Inhibition of abnormal dendritic spine remodeling can relieve neuropathic pain. Electroacupuncture (EA) has a beneficial effect on the treatment of neuropathic pain, but the specific mechanism remains unclear. Evidence has shown that slit-robo GTPase activating protein 3 (srGAP3) and Rho GTPase (Rac1) play very important roles in dendritic spine remodeling. Here, we used srGAP3 siRNA and Rac1 activator CN04 to confirm the relationship between SrGAP3 and Rac1 and their roles in improving neuropathic pain with EA. Spinal nerve ligation (SNL) was used as the experimental model, and thermal withdrawal latency (TWL), mechanical withdrawal threshold (MWT), Western blotting, immunohistochemistry and Golgi-Cox staining were used to examine changes in behavioral performance, protein expression and dendritic spines. More dendritic spines and higher expression levels of srGAP3 were found in the initial phase of neuropathic pain. During the maintenance phase, dendritic spines were more mature, which was consistent with lower expression levels of srGAP3 and higher expression levels of Rac1-GTP. EA during the maintenance phase reduced the density and maturity of dendritic spines of rats with SNL, increased the levels of srGAP3 and reduced the levels of Rac1-GTP, while srGAP3 siRNA and CN04 reversed the therapeutic effects of EA. These results suggest that dendritic spines have different manifestations in different stages of neuropathic pain and that EA may inhibit the abnormal dendritic spine remodeling by regulating the srGAP3/Rac1 signaling pathway to alleviate neuropathic pain.
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Affiliation(s)
- Qiaoyun Wu
- Department of Physical Medicine and Rehabilitation, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, 268 Xue Yuan Xi Road, Wenzhou, 325027, Zhejiang, People's Republic of China
- Integrative and Optimized Medicine Research Center, China-USA Institute for Acupuncture and Rehabilitation, Wenzhou Medical University, Wenzhou, 325027, Zhejiang, China
- The Wenzhou Key Laboratory for Rehabilitation Research, The Provincial Key Laboratory for Acupuncture and Rehabilitation in Zhejiang Province, Wenzhou, China
| | - Chenchen Cai
- Department of Physical Medicine and Rehabilitation, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, 268 Xue Yuan Xi Road, Wenzhou, 325027, Zhejiang, People's Republic of China
- Integrative and Optimized Medicine Research Center, China-USA Institute for Acupuncture and Rehabilitation, Wenzhou Medical University, Wenzhou, 325027, Zhejiang, China
- The Wenzhou Key Laboratory for Rehabilitation Research, The Provincial Key Laboratory for Acupuncture and Rehabilitation in Zhejiang Province, Wenzhou, China
| | - Xinwang Ying
- Department of Physical Medicine and Rehabilitation, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, 268 Xue Yuan Xi Road, Wenzhou, 325027, Zhejiang, People's Republic of China
- Integrative and Optimized Medicine Research Center, China-USA Institute for Acupuncture and Rehabilitation, Wenzhou Medical University, Wenzhou, 325027, Zhejiang, China
- The Wenzhou Key Laboratory for Rehabilitation Research, The Provincial Key Laboratory for Acupuncture and Rehabilitation in Zhejiang Province, Wenzhou, China
| | - Yujun Zheng
- Department of Physical Medicine and Rehabilitation, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, 268 Xue Yuan Xi Road, Wenzhou, 325027, Zhejiang, People's Republic of China
- Integrative and Optimized Medicine Research Center, China-USA Institute for Acupuncture and Rehabilitation, Wenzhou Medical University, Wenzhou, 325027, Zhejiang, China
- The Wenzhou Key Laboratory for Rehabilitation Research, The Provincial Key Laboratory for Acupuncture and Rehabilitation in Zhejiang Province, Wenzhou, China
| | - Jiaying Yu
- Department of Physical Medicine and Rehabilitation, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, 268 Xue Yuan Xi Road, Wenzhou, 325027, Zhejiang, People's Republic of China
- Integrative and Optimized Medicine Research Center, China-USA Institute for Acupuncture and Rehabilitation, Wenzhou Medical University, Wenzhou, 325027, Zhejiang, China
- The Wenzhou Key Laboratory for Rehabilitation Research, The Provincial Key Laboratory for Acupuncture and Rehabilitation in Zhejiang Province, Wenzhou, China
| | - Xiaoxue Gu
- Department of Physical Medicine and Rehabilitation, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, 268 Xue Yuan Xi Road, Wenzhou, 325027, Zhejiang, People's Republic of China
- Integrative and Optimized Medicine Research Center, China-USA Institute for Acupuncture and Rehabilitation, Wenzhou Medical University, Wenzhou, 325027, Zhejiang, China
- The Wenzhou Key Laboratory for Rehabilitation Research, The Provincial Key Laboratory for Acupuncture and Rehabilitation in Zhejiang Province, Wenzhou, China
| | - Wenzhan Tu
- Department of Physical Medicine and Rehabilitation, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, 268 Xue Yuan Xi Road, Wenzhou, 325027, Zhejiang, People's Republic of China
- Integrative and Optimized Medicine Research Center, China-USA Institute for Acupuncture and Rehabilitation, Wenzhou Medical University, Wenzhou, 325027, Zhejiang, China
- The Wenzhou Key Laboratory for Rehabilitation Research, The Provincial Key Laboratory for Acupuncture and Rehabilitation in Zhejiang Province, Wenzhou, China
| | - Xinfa Lou
- Integrative and Optimized Medicine Research Center, China-USA Institute for Acupuncture and Rehabilitation, Wenzhou Medical University, Wenzhou, 325027, Zhejiang, China
| | - Guanhu Yang
- Department of Physical Medicine and Rehabilitation, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, 268 Xue Yuan Xi Road, Wenzhou, 325027, Zhejiang, People's Republic of China
- Integrative and Optimized Medicine Research Center, China-USA Institute for Acupuncture and Rehabilitation, Wenzhou Medical University, Wenzhou, 325027, Zhejiang, China
- The Wenzhou Key Laboratory for Rehabilitation Research, The Provincial Key Laboratory for Acupuncture and Rehabilitation in Zhejiang Province, Wenzhou, China
| | - Ming Li
- School of Basic Medical Science, Wenzhou Medical University, Wenzhou, 325027, Zhejiang, China
- The Wenzhou Key Laboratory for Rehabilitation Research, The Provincial Key Laboratory for Acupuncture and Rehabilitation in Zhejiang Province, Wenzhou, China
| | - Songhe Jiang
- Department of Physical Medicine and Rehabilitation, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, 268 Xue Yuan Xi Road, Wenzhou, 325027, Zhejiang, People's Republic of China.
- Integrative and Optimized Medicine Research Center, China-USA Institute for Acupuncture and Rehabilitation, Wenzhou Medical University, Wenzhou, 325027, Zhejiang, China.
- The Wenzhou Key Laboratory for Rehabilitation Research, The Provincial Key Laboratory for Acupuncture and Rehabilitation in Zhejiang Province, Wenzhou, China.
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Xu L, Yang L, Wu Y, Wan X, Tang X, Xu Y, Chen Q, Liu Y, Liu S. Rac1/PAK1 signaling contributes to bone cancer pain by Regulation dendritic spine remodeling in rats. Mol Pain 2023; 19:17448069231161031. [PMID: 36938611 PMCID: PMC10028669 DOI: 10.1177/17448069231161031] [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] [Indexed: 03/21/2023] Open
Abstract
Bone cancer pain (BCP) is severe chronic pain caused by tumor metastasis to the bones, often resulting in significant skeletal remodeling and fractures. Currently, there is no curative treatment. Therefore, insight into the underlying mechanisms could guide the development of mechanism-based therapeutic strategies for BCP. We speculated that Rac1/PAK1 signaling plays a critical role in the development of BCP. Tumor cells implantation (TCI) into the tibial cavity resulted in bone cancer-associated mechanical allodynia. Golgi staining revealed changes in the excitatory synaptic structure of WDR (Wide-dynamic range) neurons in the spinal cord, including increased postsynaptic density (PSD) length and thickness, and width of the cleft. Behavioral and western blotting test revealed that the development and persistence of pain correlated with Rac1/PAK1 signaling activation in primary sensory neurons. Intrathecal injection of NSC23766, a Rac1 inhibitor, reduced the persistence of BCP as well as reversed the remodeling of dendrites. Therefore, we concluded that activation of the Rac1/PAK1 signaling pathway in the spinal cord plays an important role in the development of BCP through remodeling of dendritic spines. Modulation of the Rac1/PAK1 pathway may be a potential strategy for BCP treatment.
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Affiliation(s)
- Lingfei Xu
- Jiangsu Province Key Laboratory of
Anesthesiology, Jiangsu Province Key Laboratory of Anesthesia and Analgesia
Application Technology, NMPA Key Laboratory for Research and Evaluation of
Narcotic and Psychotropic Drugs, Xuzhou Medical
University, Jiangsu, China
| | - Long Yang
- Jiangsu Province Key Laboratory of
Anesthesiology, Jiangsu Province Key Laboratory of Anesthesia and Analgesia
Application Technology, NMPA Key Laboratory for Research and Evaluation of
Narcotic and Psychotropic Drugs, Xuzhou Medical
University, Jiangsu, China
| | - Yan Wu
- Jiangsu Province Key Laboratory of
Anesthesiology, Jiangsu Province Key Laboratory of Anesthesia and Analgesia
Application Technology, NMPA Key Laboratory for Research and Evaluation of
Narcotic and Psychotropic Drugs, Xuzhou Medical
University, Jiangsu, China
- Department of Anesthesiology, The Affiliated Hospital of Xuzhou
Medical University, Jiangsu, China
| | - Xinxin Wan
- Department of Anesthesiology, Nanjing Drum Tower
Hospital, Jiangsu, China
| | - Xihui Tang
- Jiangsu Province Key Laboratory of
Anesthesiology, Jiangsu Province Key Laboratory of Anesthesia and Analgesia
Application Technology, NMPA Key Laboratory for Research and Evaluation of
Narcotic and Psychotropic Drugs, Xuzhou Medical
University, Jiangsu, China
- Department of Anesthesiology, The Affiliated Hospital of Xuzhou
Medical University, Jiangsu, China
| | - Yuqing Xu
- Jiangsu Province Key Laboratory of
Anesthesiology, Jiangsu Province Key Laboratory of Anesthesia and Analgesia
Application Technology, NMPA Key Laboratory for Research and Evaluation of
Narcotic and Psychotropic Drugs, Xuzhou Medical
University, Jiangsu, China
- Department of Anesthesiology, The Affiliated Hospital of Xuzhou
Medical University, Jiangsu, China
| | - Qingsong Chen
- Jiangsu Province Key Laboratory of
Anesthesiology, Jiangsu Province Key Laboratory of Anesthesia and Analgesia
Application Technology, NMPA Key Laboratory for Research and Evaluation of
Narcotic and Psychotropic Drugs, Xuzhou Medical
University, Jiangsu, China
- Department of Anesthesiology, The Affiliated Hospital of Xuzhou
Medical University, Jiangsu, China
| | - Yuepeng Liu
- Institute of Xuzhou Medical
Science, Jiangsu, China
| | - Su Liu
- Jiangsu Province Key Laboratory of
Anesthesiology, Jiangsu Province Key Laboratory of Anesthesia and Analgesia
Application Technology, NMPA Key Laboratory for Research and Evaluation of
Narcotic and Psychotropic Drugs, Xuzhou Medical
University, Jiangsu, China
- Department of Anesthesiology, The Affiliated Hospital of Xuzhou
Medical University, Jiangsu, China
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Cui Z, Guo Z, Wei L, Zou X, Zhu Z, Liu Y, Wang J, Chen L, Wang D, Ke Z. Altered pain sensitivity in 5×familial Alzheimer disease mice is associated with dendritic spine loss in anterior cingulate cortex pyramidal neurons. Pain 2022; 163:2138-2153. [PMID: 35384934 PMCID: PMC9578529 DOI: 10.1097/j.pain.0000000000002648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 03/25/2022] [Accepted: 03/28/2022] [Indexed: 11/26/2022]
Abstract
ABSTRACT Chronic pain is highly prevalent. Individuals with cognitive disorders such as Alzheimer disease are a susceptible population in which pain is frequently difficult to diagnosis. It is still unclear whether the pathological changes in patients with Alzheimer disease will affect pain processing. Here, we leverage animal behavior, neural activity recording, optogenetics, chemogenetics, and Alzheimer disease modeling to examine the contribution of the anterior cingulate cortex (ACC) neurons to pain response. The 5× familial Alzheimer disease mice show alleviated mechanical allodynia which can be regained by the genetic activation of ACC excitatory neurons. Furthermore, the lower peak neuronal excitation, delayed response initiation, as well as the dendritic spine reduction of ACC pyramidal neurons in 5×familial Alzheimer disease mice can be mimicked by Rac1 or actin polymerization inhibitor in wild-type (WT) mice. These findings indicate that abnormal of pain sensitivity in Alzheimer disease modeling mice is closely related to the variation of neuronal activity and dendritic spine loss in ACC pyramidal neurons, suggesting the crucial role of dendritic spine density in pain processing.
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Affiliation(s)
- Zhengyu Cui
- Academy of Integrative Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China
- Department of Internal Medicine of Traditional Chinese Medicine, Shanghai East Hospital, Tongji University, Shanghai, China
| | - Zhongzhao Guo
- Academy of Integrative Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Luyao Wei
- Academy of Integrative Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Xiang Zou
- Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Zilu Zhu
- Department of Physiology, School of Basic Medical Sciences, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Yuchen Liu
- Department of Physiology, School of Basic Medical Sciences, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Jie Wang
- Academy of Integrative Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Liang Chen
- Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Deheng Wang
- Department of Physiology, School of Basic Medical Sciences, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Zunji Ke
- Academy of Integrative Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China
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Duman JG, Blanco FA, Cronkite CA, Ru Q, Erikson KC, Mulherkar S, Saifullah AB, Firozi K, Tolias KF. Rac-maninoff and Rho-vel: The symphony of Rho-GTPase signaling at excitatory synapses. Small GTPases 2022; 13:14-47. [PMID: 33955328 PMCID: PMC9707551 DOI: 10.1080/21541248.2021.1885264] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 01/22/2021] [Accepted: 01/28/2021] [Indexed: 01/15/2023] Open
Abstract
Synaptic connections between neurons are essential for every facet of human cognition and are thus regulated with extreme precision. Rho-family GTPases, molecular switches that cycle between an active GTP-bound state and an inactive GDP-bound state, comprise a critical feature of synaptic regulation. Rho-GTPases are exquisitely controlled by an extensive suite of activators (GEFs) and inhibitors (GAPs and GDIs) and interact with many different signalling pathways to fulfill their roles in orchestrating the development, maintenance, and plasticity of excitatory synapses of the central nervous system. Among the mechanisms that control Rho-GTPase activity and signalling are cell surface receptors, GEF/GAP complexes that tightly regulate single Rho-GTPase dynamics, GEF/GAP and GEF/GEF functional complexes that coordinate multiple Rho-family GTPase activities, effector positive feedback loops, and mutual antagonism of opposing Rho-GTPase pathways. These complex regulatory mechanisms are employed by the cells of the nervous system in almost every step of development, and prominently figure into the processes of synaptic plasticity that underlie learning and memory. Finally, misregulation of Rho-GTPases plays critical roles in responses to neuronal injury, such as traumatic brain injury and neuropathic pain, and in neurodevelopmental and neurodegenerative disorders, including intellectual disability, autism spectrum disorder, schizophrenia, and Alzheimer's Disease. Thus, decoding the mechanisms of Rho-GTPase regulation and function at excitatory synapses has great potential for combatting many of the biggest current challenges in mental health.
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Affiliation(s)
- Joseph G. Duman
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Francisco A. Blanco
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Integrative Molecular and Biomedical Science Graduate Program, Baylor College of Medicine, Houston, TX, USA
| | - Christopher A. Cronkite
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
- Medical Scientist Training Program, Baylor College of Medicine, Houston, TX, USA
| | - Qin Ru
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Kelly C. Erikson
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Shalaka Mulherkar
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Ali Bin Saifullah
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Karen Firozi
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Kimberley F. Tolias
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
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Khanal P, Hotulainen P. Dendritic Spine Initiation in Brain Development, Learning and Diseases and Impact of BAR-Domain Proteins. Cells 2021; 10:cells10092392. [PMID: 34572042 PMCID: PMC8468246 DOI: 10.3390/cells10092392] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 09/08/2021] [Accepted: 09/09/2021] [Indexed: 02/08/2023] Open
Abstract
Dendritic spines are small, bulbous protrusions along neuronal dendrites where most of the excitatory synapses are located. Dendritic spine density in normal human brain increases rapidly before and after birth achieving the highest density around 2-8 years. Density decreases during adolescence, reaching a stable level in adulthood. The changes in dendritic spines are considered structural correlates for synaptic plasticity as well as the basis of experience-dependent remodeling of neuronal circuits. Alterations in spine density correspond to aberrant brain function observed in various neurodevelopmental and neuropsychiatric disorders. Dendritic spine initiation affects spine density. In this review, we discuss the importance of spine initiation in brain development, learning, and potential complications resulting from altered spine initiation in neurological diseases. Current literature shows that two Bin Amphiphysin Rvs (BAR) domain-containing proteins, MIM/Mtss1 and SrGAP3, are involved in spine initiation. We review existing literature and open databases to discuss whether other BAR-domain proteins could also take part in spine initiation. Finally, we discuss the potential molecular mechanisms on how BAR-domain proteins could regulate spine initiation.
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Affiliation(s)
- Pushpa Khanal
- Minerva Foundation Institute for Medical Research, Tukholmankatu 8, 00290 Helsinki, Finland;
- HiLIFE-Neuroscience Center, University of Helsinki, 00014 Helsinki, Finland
| | - Pirta Hotulainen
- Minerva Foundation Institute for Medical Research, Tukholmankatu 8, 00290 Helsinki, Finland;
- Correspondence:
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10
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Characterisation of lamina I anterolateral system neurons that express Cre in a Phox2a-Cre mouse line. Sci Rep 2021; 11:17912. [PMID: 34504158 PMCID: PMC8429737 DOI: 10.1038/s41598-021-97105-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 08/10/2021] [Indexed: 11/13/2022] Open
Abstract
A recently developed Phox2a::Cre mouse line has been shown to capture anterolateral system (ALS) projection neurons. Here, we used this line to test whether Phox2a-positive cells represent a distinct subpopulation among lamina I ALS neurons. We show that virtually all lamina I Phox2a cells can be retrogradely labelled from injections targeted on the lateral parabrachial area (LPb), and that most of those in the cervical cord also belong to the spinothalamic tract. Phox2a cells accounted for ~ 50–60% of the lamina I cells retrogradely labelled from LPb or thalamus. Phox2a was preferentially associated with smaller ALS neurons, and with those showing relatively weak neurokinin 1 receptor expression. The Phox2a cells were also less likely to project to the ipsilateral LPb. Although most Phox2a cells phosphorylated extracellular signal-regulated kinases following noxious heat stimulation, ~ 20% did not, and these were significantly smaller than the activated cells. This suggests that those ALS neurons that respond selectively to skin cooling, which have small cell bodies, may be included among the Phox2a population. Previous studies have defined neurochemical populations among the ALS cells, based on expression of Tac1 or Gpr83. However, we found that the proportions of Phox2a cells that expressed these genes were similar to the proportions reported for all lamina I ALS neurons, suggesting that Phox2a is not differentially expressed among cells belonging to these populations. Finally, we used a mouse line that resulted in membrane labelling of the Phox2a cells and showed that they all possess dendritic spines, although at a relatively low density. However, the distribution of the postsynaptic protein Homer revealed that dendritic spines accounted for a minority of the excitatory synapses on these cells. Our results confirm that Phox2a-positive cells in lamina I are ALS neurons, but show that the Phox2a::Cre line preferentially captures specific types of ALS cells.
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11
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Guiler W, Koehler A, Boykin C, Lu Q. Pharmacological Modulators of Small GTPases of Rho Family in Neurodegenerative Diseases. Front Cell Neurosci 2021; 15:661612. [PMID: 34054432 PMCID: PMC8149604 DOI: 10.3389/fncel.2021.661612] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 04/08/2021] [Indexed: 12/22/2022] Open
Abstract
Classical Rho GTPases, including RhoA, Rac1, and Cdc42, are members of the Ras small GTPase superfamily and play essential roles in a variety of cellular functions. Rho GTPase signaling can be turned on and off by specific GEFs and GAPs, respectively. These features empower Rho GTPases and their upstream and downstream modulators as targets for scientific research and therapeutic intervention. Specifically, significant therapeutic potential exists for targeting Rho GTPases in neurodegenerative diseases due to their widespread cellular activity and alterations in neural tissues. This study will explore the roles of Rho GTPases in neurodegenerative diseases with focus on the applications of pharmacological modulators in recent discoveries. There have been exciting developments of small molecules, nonsteroidal anti-inflammatory drugs (NSAIDs), and natural products and toxins for each classical Rho GTPase category. A brief overview of each category followed by examples in their applications will be provided. The literature on their roles in various diseases [e.g., Alzheimer's disease (AD), Parkinson's disease (PD), Amyotrophic lateral sclerosis (ALS), Frontotemporal dementia (FTD), and Multiple sclerosis (MS)] highlights the unique and broad implications targeting Rho GTPases for potential therapeutic intervention. Clearly, there is increasing knowledge of therapeutic promise from the discovery of pharmacological modulators of Rho GTPases for managing and treating these conditions. The progress is also accompanied by the recognition of complex Rho GTPase modulation where targeting its signaling can improve some aspects of pathogenesis while exacerbating others in the same disease model. Future directions should emphasize the importance of elucidating how different Rho GTPases work in concert and how they produce such widespread yet different cellular responses during neurodegenerative disease progression.
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Affiliation(s)
| | | | | | - Qun Lu
- Department of Anatomy and Cell Biology, The Harriet and John Wooten Laboratory for Alzheimer’s and Neurogenerative Diseases Research, Brody School of Medicine, East Carolina University, Greenville, NC, United States
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12
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Conditional RAC1 knockout in motor neurons restores H-reflex rate-dependent depression after spinal cord injury. Sci Rep 2021; 11:7838. [PMID: 33837249 PMCID: PMC8035187 DOI: 10.1038/s41598-021-87476-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 03/30/2021] [Indexed: 12/27/2022] Open
Abstract
A major complication with spinal cord injury (SCI) is the development of spasticity, a clinical symptom of hyperexcitability within the spinal H-reflex pathway. We have previously demonstrated a common structural motif of dendritic spine dysgenesis associated with hyperexcitability disorders after injury or disease insults to the CNS. Here, we used an adeno-associated viral (AAV)-mediated Cre-Lox system to knockout Rac1 protein expression in motor neurons after SCI. Three weeks after AAV9-Cre delivery into the soleus/gastrocnemius of Rac1-“floxed” adult mice to retrogradely infect spinal alpha-motor neurons, we observed significant restoration of RDD and reduced H-reflex excitability in SCI animals. Additionally, viral-mediated Rac1 knockdown reduced presence of dendritic spine dysgenesis on motor neurons. In control SCI animals without Rac1 knockout, we continued to observe abnormal dendritic spine morphology associated with hyperexcitability disorder, including an increase in mature, mushroom dendritic spines, and an increase in overall spine length and spine head size. Taken together, our results demonstrate that viral-mediated disruption of Rac1 expression in ventral horn motor neurons can mitigate dendritic spine morphological correlates of neuronal hyperexcitability, and reverse hyperreflexia associated with spasticity after SCI. Finally, our findings provide evidence of a putative mechanistic relationship between motor neuron dendritic spine dysgenesis and SCI-induced spasticity.
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13
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Wang JL, Wang Y, Sun W, Yu Y, Wei N, Du R, Yang Y, Liang T, Wang XL, Ou CH, Chen J. Spinophilin modulates pain through suppressing dendritic spine morphogenesis via negative control of Rac1-ERK signaling in rat spinal dorsal horn. Neurobiol Dis 2021; 152:105302. [PMID: 33609640 DOI: 10.1016/j.nbd.2021.105302] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 01/07/2021] [Accepted: 02/14/2021] [Indexed: 01/07/2023] Open
Abstract
Both spinophilin (SPN, also known as neurabin 2) and Rac1 (a member of Rho GTPase family) are believed to play key roles in dendritic spine (DS) remodeling and spinal nociception. However, how SPN interacts with Rac1 in the above process is unknown. Here, we first demonstrated natural existence of SPN-protein phosphatase 1-Rac1 complex in the spinal dorsal horn (DH) neurons by both double immunofluorescent labeling and co-immunoprecipitation, then the effects of SPN over-expression and down-regulation on mechanical and thermal pain sensitivity, GTP-bound Rac1-ERK signaling activity, and spinal DS density were studied. Over-expression of SPN in spinal neurons by intra-DH pAAV-CMV-SPN-3FLAG could block both mechanical and thermal pain hypersensitivity induced by intraplantar bee venom injection, however it had no effect on the basal pain sensitivity. Over-expression of SPN also resulted in a significant decrease in GTP-Rac1-ERK activities, relative to naive and irrelevant control (pAAV-MCS). In sharp contrast, knockdown of SPN in spinal neurons by intra-DH pAAV-CAG-eGFP-U6-shRNA[SPN] produced both pain hypersensitivity and dramatic elevation of GTP-Rac1-ERK activities, relative to naive and irrelevant control (pAAV-shRNA [NC]). Moreover, knockdown of SPN resulted in increase in DS density while over-expression of it had no such effect. Collectively, SPN is likely to serve as a regulator of Rac1 signaling to suppress DS morphogenesis via negative control of GTP-bound Rac1-ERK activities at postsynaptic component in rat DH neurons wherein both mechanical and thermal pain sensitivity are controlled.
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Affiliation(s)
- Jiang-Lin Wang
- Institute for Biomedical Sciences of Pain, Tangdu Hospital, The Fourth Military Medical University, Xi'an 710038, Shaanxi Province, PR China; Department of Pain Management, The Affiliated Hospital of Southwest Medical University, Luzhou 646000, Sichuan Province, PR China
| | - Yan Wang
- Institute for Biomedical Sciences of Pain, Tangdu Hospital, The Fourth Military Medical University, Xi'an 710038, Shaanxi Province, PR China; Key Laboratory of Brain Stress and Behavior, People's Liberation Army, Xi'an 710038, PR China
| | - Wei Sun
- Institute for Biomedical Sciences of Pain, Tangdu Hospital, The Fourth Military Medical University, Xi'an 710038, Shaanxi Province, PR China; Key Laboratory of Brain Stress and Behavior, People's Liberation Army, Xi'an 710038, PR China
| | - Yang Yu
- Institute for Biomedical Sciences of Pain, Tangdu Hospital, The Fourth Military Medical University, Xi'an 710038, Shaanxi Province, PR China; Key Laboratory of Brain Stress and Behavior, People's Liberation Army, Xi'an 710038, PR China
| | - Na Wei
- Institute for Biomedical Sciences of Pain, Tangdu Hospital, The Fourth Military Medical University, Xi'an 710038, Shaanxi Province, PR China; Key Laboratory of Brain Stress and Behavior, People's Liberation Army, Xi'an 710038, PR China
| | - Rui Du
- Institute for Biomedical Sciences of Pain, Tangdu Hospital, The Fourth Military Medical University, Xi'an 710038, Shaanxi Province, PR China; Key Laboratory of Brain Stress and Behavior, People's Liberation Army, Xi'an 710038, PR China
| | - Yan Yang
- Institute for Biomedical Sciences of Pain, Tangdu Hospital, The Fourth Military Medical University, Xi'an 710038, Shaanxi Province, PR China; Key Laboratory of Brain Stress and Behavior, People's Liberation Army, Xi'an 710038, PR China
| | - Ting Liang
- Institute for Biomedical Sciences of Pain, Tangdu Hospital, The Fourth Military Medical University, Xi'an 710038, Shaanxi Province, PR China; Key Laboratory of Brain Stress and Behavior, People's Liberation Army, Xi'an 710038, PR China
| | - Xiao-Liang Wang
- Institute for Biomedical Sciences of Pain, Tangdu Hospital, The Fourth Military Medical University, Xi'an 710038, Shaanxi Province, PR China; Key Laboratory of Brain Stress and Behavior, People's Liberation Army, Xi'an 710038, PR China
| | - Ce-Hua Ou
- Department of Pain Management, The Affiliated Hospital of Southwest Medical University, Luzhou 646000, Sichuan Province, PR China
| | - Jun Chen
- Institute for Biomedical Sciences of Pain, Tangdu Hospital, The Fourth Military Medical University, Xi'an 710038, Shaanxi Province, PR China; Key Laboratory of Brain Stress and Behavior, People's Liberation Army, Xi'an 710038, PR China.
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14
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Sculpting Dendritic Spines during Initiation and Maintenance of Neuropathic Pain. J Neurosci 2021; 40:7578-7589. [PMID: 32998955 DOI: 10.1523/jneurosci.1664-20.2020] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/31/2020] [Accepted: 08/21/2020] [Indexed: 12/21/2022] Open
Abstract
Accumulating evidence has established a firm role for synaptic plasticity in the pathogenesis of neuropathic pain. Recent advances have highlighted the importance of dendritic spine remodeling in driving synaptic plasticity within the CNS. Identifying the molecular players underlying neuropathic pain induced structural and functional maladaptation is therefore critical to understanding its pathophysiology. This process of dynamic reorganization happens in unique phases that have diverse pathologic underpinnings in the initiation and maintenance of neuropathic pain. Recent evidence suggests that pharmacological targeting of specific proteins during distinct phases of neuropathic pain development produces enhanced antinociception. These findings outline a potential new paradigm for targeted treatment and the development of novel therapies for neuropathic pain. We present a concise review of the role of dendritic spines in neuropathic pain and outline the potential for modulation of spine dynamics by targeting two proteins, srGAP3 and Rac1, critically involved in the regulation of the actin cytoskeleton.
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15
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Kober KM, Schumacher M, Conley YP, Topp K, Mazor M, Hammer MJ, Paul SM, Levine JD, Miaskowski C. Signaling pathways and gene co-expression modules associated with cytoskeleton and axon morphology in breast cancer survivors with chronic paclitaxel-induced peripheral neuropathy. Mol Pain 2020; 15:1744806919878088. [PMID: 31486345 PMCID: PMC6755139 DOI: 10.1177/1744806919878088] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Background The major dose-limiting toxicity of paclitaxel, one of the most commonly used
drugs to treat breast cancer, is peripheral neuropathy (paclitaxel-induced
peripheral neuropathy). Paclitaxel-induced peripheral neuropathy, which
persists into survivorship, has a negative impact on patient’s mood,
functional status, and quality of life. Currently, no interventions are
available to treat paclitaxel-induced peripheral neuropathy. A critical
barrier to the development of efficacious interventions is the lack of
understanding of the mechanisms that underlie paclitaxel-induced peripheral
neuropathy. While data from preclinical studies suggest that disrupting
cytoskeleton- and axon morphology-related processes are a potential
mechanism for paclitaxel-induced peripheral neuropathy, clinical evidence is
limited. The purpose of this study in breast cancer survivors was to
evaluate whether differential gene expression and co-expression patterns in
these pathways are associated with paclitaxel-induced peripheral
neuropathy. Methods Signaling pathways and gene co-expression modules associated with
cytoskeleton and axon morphology were identified between survivors who
received paclitaxel and did (n = 25) or did not (n = 25) develop
paclitaxel-induced peripheral neuropathy. Results Pathway impact analysis identified four significantly perturbed cytoskeleton-
and axon morphology-related signaling pathways. Weighted gene co-expression
network analysis identified three co-expression modules. One module was
associated with paclitaxel-induced peripheral neuropathy group membership.
Functional analysis found that this module was associated with four
signaling pathways and two ontology annotations related to cytoskeleton and
axon morphology. Conclusions This study, which is the first to apply systems biology approaches using
circulating whole blood RNA-seq data in a sample of breast cancer survivors
with and without chronic paclitaxel-induced peripheral neuropathy, provides
molecular evidence that cytoskeleton- and axon morphology-related mechanisms
identified in preclinical models of various types of neuropathic pain
including chemotherapy-induced peripheral neuropathy are found in breast
cancer survivors and suggests pathways and a module of genes for validation
and as potential therapeutic targets.
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Affiliation(s)
- Kord M Kober
- School of Nursing, University of California, San Francisco, CA, USA
| | - Mark Schumacher
- School of Medicine, University of California, San Francisco, CA, USA
| | - Yvette P Conley
- School of Nursing, University of Pittsburgh, Pittsburgh, PA, USA
| | - Kimberly Topp
- School of Medicine, University of California, San Francisco, CA, USA
| | - Melissa Mazor
- School of Nursing, University of California, San Francisco, CA, USA
| | - Marilynn J Hammer
- Icahn School of Medicine, Mount Sinai Medical Center, New York, NY, USA
| | - Steven M Paul
- School of Nursing, University of California, San Francisco, CA, USA
| | - Jon D Levine
- School of Medicine, University of California, San Francisco, CA, USA
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16
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Patwa S, Benson CA, Dyer L, Olson K, Bangalore L, Hill M, Waxman SG, Tan AM. Spinal cord motor neuron plasticity accompanies second-degree burn injury and chronic pain. Physiol Rep 2019; 7:e14288. [PMID: 31858746 PMCID: PMC6923170 DOI: 10.14814/phy2.14288] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Burn injuries and associated complications present a major public health challenge. Many burn patients develop clinically intractable complications, including pain and other sensory disorders. Recent evidence has shown that dendritic spine neuropathology in spinal cord sensory and motor neurons accompanies central nervous system (CNS) or peripheral nervous system (PNS) trauma and disease. However, no research has investigated similar dendritic spine neuropathologies following a cutaneous thermal burn injury. In this retrospective investigation, we analyzed dendritic spine morphology and localization in alpha-motor neurons innervating a burn-injured area of the body (hind paw). To identify a molecular regulator of these dendritic spine changes, we further profiled motor neuron dendritic spines in adult mice treated with romidepsin, a clinically approved Pak1-inhibitor, or vehicle control at two postburn time points: Day 6 immediately after treatment, or Day 10 following drug withdrawal. In control treated mice, we observed an overall increase in dendritic spine density, including structurally mature spines with mushroom-shaped morphology. Pak1-inhibitor treatment reduced injury-induced changes to similar levels observed in animals without burn injury. The effectiveness of the Pak1-inhibitor was durable, since normalized dendritic spine profiles remained as long as 4 days despite drug withdrawal. This study is the first report of evidence demonstrating that a second-degree burn injury significantly affects motor neuron structure within the spinal cord. Furthermore, our results support the opportunity to study dendritic spine dysgenesis as a novel avenue to clarify the complexities of neurological disease following traumatic injury.
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Affiliation(s)
- Siraj Patwa
- Department of Neurology and Center for Neuroscience and Regeneration ResearchYale University School of MedicineNew HavenConnecticut
- Rehabilitation Research CenterVeterans Affairs Connecticut Healthcare SystemWest HavenConnecticut
| | - Curtis A. Benson
- Department of Neurology and Center for Neuroscience and Regeneration ResearchYale University School of MedicineNew HavenConnecticut
- Rehabilitation Research CenterVeterans Affairs Connecticut Healthcare SystemWest HavenConnecticut
| | - Lauren Dyer
- Department of Neurology and Center for Neuroscience and Regeneration ResearchYale University School of MedicineNew HavenConnecticut
- Rehabilitation Research CenterVeterans Affairs Connecticut Healthcare SystemWest HavenConnecticut
| | - Kai‐Lan Olson
- Department of Neurology and Center for Neuroscience and Regeneration ResearchYale University School of MedicineNew HavenConnecticut
- Rehabilitation Research CenterVeterans Affairs Connecticut Healthcare SystemWest HavenConnecticut
| | - Lakshmi Bangalore
- Department of Neurology and Center for Neuroscience and Regeneration ResearchYale University School of MedicineNew HavenConnecticut
- Rehabilitation Research CenterVeterans Affairs Connecticut Healthcare SystemWest HavenConnecticut
| | - Myriam Hill
- Department of Neurology and Center for Neuroscience and Regeneration ResearchYale University School of MedicineNew HavenConnecticut
- Rehabilitation Research CenterVeterans Affairs Connecticut Healthcare SystemWest HavenConnecticut
| | - Stephen G. Waxman
- Department of Neurology and Center for Neuroscience and Regeneration ResearchYale University School of MedicineNew HavenConnecticut
- Rehabilitation Research CenterVeterans Affairs Connecticut Healthcare SystemWest HavenConnecticut
| | - Andrew M. Tan
- Department of Neurology and Center for Neuroscience and Regeneration ResearchYale University School of MedicineNew HavenConnecticut
- Rehabilitation Research CenterVeterans Affairs Connecticut Healthcare SystemWest HavenConnecticut
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17
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Bayir Y, Un H, Ugan RA, Akpinar E, Cadirci E, Calik I, Halici Z. The effects of Beeswax, Olive oil and Butter impregnated bandage on burn wound healing. Burns 2019; 45:1410-1417. [DOI: 10.1016/j.burns.2018.03.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 02/10/2018] [Accepted: 03/09/2018] [Indexed: 12/29/2022]
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18
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Alterations in evoked and spontaneous activity of dorsal horn wide dynamic range neurons in pathological pain: a systematic review and analysis. Pain 2019; 160:2199-2209. [DOI: 10.1097/j.pain.0000000000001632] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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19
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Morgan M, Deuis JR, Frøsig-Jørgensen M, Lewis RJ, Cabot PJ, Gray PD, Vetter I. Burn Pain: A Systematic and Critical Review of Epidemiology, Pathophysiology, and Treatment. PAIN MEDICINE 2019; 19:708-734. [PMID: 29036469 DOI: 10.1093/pm/pnx228] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Objective This review aims to examine the available literature on the epidemiology, pathophysiology, and treatment of burn-induced pain. Methods A search was conducted on the epidemiology of burn injury and treatment of burn pain utilizing the database Medline, and all relevant articles were systemically reviewed. In addition, a critical review was performed on the pathophysiology of burn pain and animal models of burn pain. Results The search on the epidemiology of burn injury yielded a total of 163 publications of interest, 72 of which fit the inclusion/exclusion criteria, with no publications providing epidemiological data on burn injury pain management outcomes. The search on the treatment of burn pain yielded a total of 213 publications, 14 of which fit the inclusion/exclusion criteria, highlighting the limited amount of evidence available on the treatment of burn-induced pain. Conclusions The pathophysiology of burn pain is poorly understood, with limited clinical trials available to assess the effectiveness of analgesics in burn patients. Further studies are needed to identify new pharmacological targets and treatments for the effective management of burn injury pain.
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Affiliation(s)
- Michael Morgan
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia
| | - Jennifer R Deuis
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia
| | - Majbrit Frøsig-Jørgensen
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia
| | - Richard J Lewis
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia
| | - Peter J Cabot
- School of Pharmacy, The University of Queensland, Wooloongabba, Queensland, Australia
| | - Paul D Gray
- Tess Cramond Multidisciplinary Pain Centre, Royal Brisbane & Women's Hospital, Metro North Health, Herston, Queensland, Australia.,School of Medicine, The University of Queensland, Herston, Queensland, Australia
| | - Irina Vetter
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia.,School of Pharmacy, The University of Queensland, Wooloongabba, Queensland, Australia
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20
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Guo Y, Benson C, Hill M, Henry S, Effraim P, Waxman SG, Dib-Hajj S, Tan AM. Therapeutic potential of Pak1 inhibition for pain associated with cutaneous burn injury. Mol Pain 2018; 14:1744806918788648. [PMID: 29956587 PMCID: PMC6053256 DOI: 10.1177/1744806918788648] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 06/01/2018] [Accepted: 06/08/2018] [Indexed: 01/20/2023] Open
Abstract
Painful burn injuries are among the most debilitating form of trauma, globally ranking in the top 15 leading causes of chronic disease burden. Despite its prevalence, however, chronic pain after burn injury is under-studied. We previously demonstrated the contribution of the Rac1-signaling pathway in several models of neuropathic pain, including burn injury. However, Rac1 belongs to a class of GTPases with low therapeutic utility due to their complex intracellular dynamics. To further understand the mechanistic underpinnings of burn-induced neuropathic pain, we performed a longitudinal study to address the hypothesis that inhibition of the downstream effector of Rac1, Pak1, will improve pain outcome following a second-degree burn injury. Substantial evidence has identified Pak1 as promising a clinical target in cognitive dysfunction and is required for dendritic spine dysgenesis associated with many neurological diseases. In our burn injury model, mice exhibited significant tactile allodynia and heat hyperalgesia and dendritic spine dysgenesis in the dorsal horn. Activity-dependent expression of c-fos also increased in dorsal horn neurons, an indicator of elevated central nociceptive activity. To inhibit Pak1, we repurposed an FDA-approved inhibitor, romidepsin. Treatment with romidepsin decreased dendritic spine dysgenesis, reduced c-fos expression, and rescued pain thresholds. Drug discontinuation resulted in a relapse of cellular correlates of pain and in lower pain thresholds in behavioral tests. Taken together, our findings identify Pak1 signaling as a potential molecular target for therapeutic intervention in traumatic burn-induced neuropathic pain.
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Affiliation(s)
- Yiqun Guo
- Department of Neurology, Center for Neuroscience and
Regeneration Research,
Yale
University School of Medicine, New
Haven, CT, USA
- Rehabilitation Research Center, Veterans Affairs Connecticut
Healthcare System, West Haven, CT, USA
| | - Curtis Benson
- Department of Neurology, Center for Neuroscience and
Regeneration Research,
Yale
University School of Medicine, New
Haven, CT, USA
- Rehabilitation Research Center, Veterans Affairs Connecticut
Healthcare System, West Haven, CT, USA
| | - Myriam Hill
- Department of Neurology, Center for Neuroscience and
Regeneration Research,
Yale
University School of Medicine, New
Haven, CT, USA
- Rehabilitation Research Center, Veterans Affairs Connecticut
Healthcare System, West Haven, CT, USA
| | - Stefanie Henry
- Department of Neurology, Center for Neuroscience and
Regeneration Research,
Yale
University School of Medicine, New
Haven, CT, USA
- Rehabilitation Research Center, Veterans Affairs Connecticut
Healthcare System, West Haven, CT, USA
| | - Philip Effraim
- Department of Neurology, Center for Neuroscience and
Regeneration Research,
Yale
University School of Medicine, New
Haven, CT, USA
- Rehabilitation Research Center, Veterans Affairs Connecticut
Healthcare System, West Haven, CT, USA
| | - Stephen G Waxman
- Department of Neurology, Center for Neuroscience and
Regeneration Research,
Yale
University School of Medicine, New
Haven, CT, USA
- Rehabilitation Research Center, Veterans Affairs Connecticut
Healthcare System, West Haven, CT, USA
| | - Sulayman Dib-Hajj
- Department of Neurology, Center for Neuroscience and
Regeneration Research,
Yale
University School of Medicine, New
Haven, CT, USA
- Rehabilitation Research Center, Veterans Affairs Connecticut
Healthcare System, West Haven, CT, USA
| | - Andrew M Tan
- Department of Neurology, Center for Neuroscience and
Regeneration Research,
Yale
University School of Medicine, New
Haven, CT, USA
- Rehabilitation Research Center, Veterans Affairs Connecticut
Healthcare System, West Haven, CT, USA
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21
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Abstract
Peripheral neuropathy and nerve compression syndromes lead to substantial morbidity following burn injury. Patients present with pain, paresthesias, or weakness along a specific nerve distribution or experience generalized peripheral neuropathy. The symptoms manifest at various times from within one week of hospitalization to many months after wound closure. Peripheral neuropathy may be caused by vascular occlusion of vasa nervorum, inflammation, neurotoxin production leading to apoptosis, and direct destruction of nerves from the burn injury. This article discusses the natural history, diagnosis, current treatments, and future directions for potential interventions for peripheral neuropathy and nerve compression syndromes related to burn injury.
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22
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Kubota T, Ishikawa Y, Ishikawa R. Spinal Cord Stimulation Treatment for Persistent Pain After a Burn Injury: A Case Report. ACTA ACUST UNITED AC 2017; 9:35-37. [PMID: 28306581 DOI: 10.1213/xaa.0000000000000519] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Spinal cord stimulation (SCS) is used to treat neuropathic pain, but there are no published studies on its use to treat burn pain. We used SCS to treat a 67-year-old man suffering from burn pain that could not be managed with high-dose opioids or adjuvant neuropathic analgesics. A trial of SCS markedly reduced the visual analog scale score for pain in the left lateral abdominal and gluteal regions. He underwent permanent implantation of a SCS and achieved an opioid-free state. This case suggests that SCS treatment is a therapeutic option for burn pain refractory to conventional therapy.
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Affiliation(s)
- Takeshi Kubota
- From the Department of Anesthesia, Hachinohe Heiwa Hospital, Hachinohe, Japan
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23
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George E, Elman I, Becerra L, Berg S, Borsook D. Pain in an era of armed conflicts: Prevention and treatment for warfighters and civilian casualties. Prog Neurobiol 2016; 141:25-44. [PMID: 27084355 DOI: 10.1016/j.pneurobio.2016.04.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 03/23/2016] [Accepted: 04/08/2016] [Indexed: 12/13/2022]
Abstract
Chronic pain is a common squealae of military- and terror-related injuries. While its pathophysiology has not yet been fully elucidated, it may be potentially related to premorbid neuropsychobiological status, as well as to the type of injury and to the neural alterations that it may evoke. Accordingly, optimized approaches for wounded individuals should integrate primary, secondary and tertiary prevention in the form of thorough evaluation of risk factors along with specific interventions to contravene and mitigate the ensuing chronicity. Thus, Premorbid Events phase may encompass assessments of psychological and neurobiological vulnerability factors in conjunction with fostering preparedness and resilience in both military and civilian populations at risk. Injuries per se phase calls for immediate treatment of acute pain in the field by pharmacological agents that spare and even enhance coping and adaptive capabilities. The key objective of the Post Injury Events is to prevent and/or reverse maladaptive peripheral- and central neural system's processes that mediate transformation of acute to chronic pain and to incorporate timely interventions for concomitant mental health problems including post-traumatic stress disorder and addiction We suggest that the proposed continuum of care may avert more disability and suffering than the currently employed less integrated strategies. While the requirements of the armed forces present a pressing need for this integrated continuum and a framework in which it can be most readily implemented, this approach may be also instrumental for the care of civilian casualties.
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Affiliation(s)
- E George
- Center for Pain and the Brain, Harvard Medical School (HMS), United States; Department of Anesthesia, Critical Care and Pain Medicine, MGH, HMS, Boston, MA, United States; Commander, MC, USN (Ret), United States
| | - I Elman
- Center for Pain and the Brain, Harvard Medical School (HMS), United States; Department of Psychiatry, Boonshoft School of Medicine and Dayton VA Medical Center, United States; Veterans Administration Medical Center, Dayton, OH, United States
| | - L Becerra
- Center for Pain and the Brain, Harvard Medical School (HMS), United States; Department of Anesthesia, Critical Care and Pain Medicine, BCH, HMS, Boston, MA, United States; Departments of Psychiatry and Radiology, MGH, Boston, MA, United States
| | - Sheri Berg
- Center for Pain and the Brain, Harvard Medical School (HMS), United States; Department of Anesthesia, Critical Care and Pain Medicine, MGH, HMS, Boston, MA, United States
| | - D Borsook
- Center for Pain and the Brain, Harvard Medical School (HMS), United States; Department of Anesthesia, Critical Care and Pain Medicine, BCH, HMS, Boston, MA, United States; Departments of Psychiatry and Radiology, MGH, Boston, MA, United States.
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24
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Zhao P, Hill M, Liu S, Chen L, Bangalore L, Waxman SG, Tan AM. Dendritic spine remodeling following early and late Rac1 inhibition after spinal cord injury: evidence for a pain biomarker. J Neurophysiol 2016; 115:2893-910. [PMID: 26936986 DOI: 10.1152/jn.01057.2015] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 03/01/2016] [Indexed: 12/15/2022] Open
Abstract
Neuropathic pain is a significant complication following spinal cord injury (SCI) with few effective treatments. Drug development for neuropathic pain often fails because preclinical studies do not always translate well to clinical conditions. Identification of biological characteristics predictive of disease state or drug responsiveness could facilitate more effective clinical translation. Emerging evidence indicates a strong correlation between dendritic spine dysgenesis and neuropathic pain. Because dendritic spines are located on dorsal horn neurons within the spinal cord nociceptive system, dendritic spine remodeling provides a unique opportunity to understand sensory dysfunction after SCI. In this study, we provide support for the postulate that dendritic spine profiles can serve as biomarkers for neuropathic pain. We show that dendritic spine profiles after SCI change to a dysgenic state that is characteristic of neuropathic pain in a Rac1-dependent manner. Suppression of the dysgenic state through inhibition of Rac1 activity is accompanied by attenuation of neuropathic pain. Both dendritic spine dysgenesis and neuropathic pain return when inhibition of Rac1 activity is lifted. These findings suggest the utility of dendritic spines as structural biomarkers for neuropathic pain.
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Affiliation(s)
- Peng Zhao
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut; and Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut
| | - Myriam Hill
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut; and Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut
| | - Shujun Liu
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut; and Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut
| | - Lubin Chen
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut; and Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut
| | - Lakshmi Bangalore
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut; and Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut
| | - Stephen G Waxman
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut; and Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut
| | - Andrew M Tan
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut; and Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut
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25
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McIntyre MK, Clifford JL, Maani CV, Burmeister DM. Progress of clinical practice on the management of burn-associated pain: Lessons from animal models. Burns 2016; 42:1161-72. [PMID: 26906668 DOI: 10.1016/j.burns.2016.01.023] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 01/05/2016] [Accepted: 01/21/2016] [Indexed: 02/08/2023]
Abstract
Opioid-based analgesics provide the mainstay for attenuating burn pain, but they have a myriad of side effects including respiratory depression, nausea, impaired gastrointestinal motility, sedation, dependence, physiologic tolerance, and opioid-induced hyperalgesia. To test and develop novel analgesics, validated burn-relevant animal models of pain are indispensable. Herein we review such animal models, which are mostly limited to rodent models of burn-induced, inflammatory, and neuropathic pain. The latter two are pain syndromes that provide insight into the pain caused by systemic pro-inflammatory cytokines and direct injury to nerves (e.g., after severe burn), respectively. To date, no single animal model optimally mimics the complex pathophysiology and pain that a human burn patient experiences. No currently available burn-pain model examines effects of pharmacological intervention on wound healing. As cornerstones of pain and wound healing, pro-inflammatory mediators may be utilized for insight into both processes. Moreover, common clinical concerns such as systemic inflammatory response syndrome and multiple organ dysfunction remain unaddressed. For development of analgesics, these aberrations can significantly alter the potential efficacy and/or adverse effects of a prescribed analgesic following burn trauma. We therefore suggest that a multi-model strategy would be the most clinically relevant when evaluating novel analgesics for use in burn patients.
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Affiliation(s)
- Matthew K McIntyre
- United States Army Institute of Surgical Research, 3650 Chambers Pass, BHT1:Bldg 3610, JBSA Fort Sam Houston, TX 78234-6315, United States.
| | - John L Clifford
- United States Army Institute of Surgical Research, 3650 Chambers Pass, BHT1:Bldg 3610, JBSA Fort Sam Houston, TX 78234-6315, United States.
| | - Christopher V Maani
- Brooke Army Medical Center, Department of Anesthesia and Operative Services, San Antonio Uniformed Services Health Education Consortium (SAUSHEC) Anesthesia Residency Program, 3551 Roger Brooke Drive, JBSA Fort Sam Houston, TX 78234-6315, United States.
| | - David M Burmeister
- United States Army Institute of Surgical Research, 3650 Chambers Pass, BHT1:Bldg 3610, JBSA Fort Sam Houston, TX 78234-6315, United States.
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26
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Wang Y, Lu YF, Li CL, Sun W, Li Z, Wang RR, He T, Yang F, Yang Y, Wang XL, Guan SM, Chen J. Involvement of Rac1 signalling pathway in the development and maintenance of acute inflammatory pain induced by bee venom injection. Br J Pharmacol 2016; 173:937-50. [PMID: 26700000 DOI: 10.1111/bph.13413] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 12/10/2015] [Accepted: 12/12/2015] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE The Rho GTPase, Rac1, is involved in the pathogenesis of neuropathic pain induced by malformation of dendritic spines in the spinal dorsal horn (sDH) neurons. In the present study, the contribution of spinal Rac1 to peripheral inflammatory pain was studied. EXPERIMENTAL APPROACH Effects of s.c. bee venom (BV) injection on cellular localization of Rac1 in the rat sDH was determined with double labelling immunofluorescence. Activation of Rac1 and its downstream effector p21-activated kinase (PAK), ERKs and p38 MAPK in inflammatory pain states was evaluated with a pull-down assay and Western blotting. The preventive and therapeutic analgesic effects of intrathecal administration of NSC23766, a selective inhibitor of Rac1, on BV-induced spontaneous nociception and pain hypersensitivity were investigated. KEY RESULTS Rac1 labelling was mainly localized within neurons in both the superficial and deep layers of the sDH in rats of naïve, vehicle-treated and inflamed (BV injected) groups. GTP-Rac1-PAK and ERKs/p38 were activated following s.c. BV injection. Post-treatment with intrathecal NSC23766 significantly inhibited GTP-Rac1 activity and phosphorylation of Rac1-PAK, ERKs and p38 MAPK in the sDH. Both pre-treatment and post-treatment with intrathecal NSC23766 dose-dependently attenuated the paw flinches, primary thermal and mechanical hyperalgesia and the mirror-image thermal hyperalgesia induced by BV injection, but without affecting the baseline pain sensitivity and motor coordination. CONCLUSIONS AND IMPLICATIONS The spinal GTP-Rac1-PAK-ERK/p38MAPK signalling pathway is involved in both the development and maintenance of peripheral inflammatory pain and can be used as a potential molecular target for developing a novel therapeutic strategy for clinical pain.
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Affiliation(s)
- Yan Wang
- Institute for Biomedical Sciences of Pain, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China.,Institute for Functional Brain Disorders, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China.,Key Laboratory of Brain Stress and Behavior, PLA, Xi'an, 710038, China
| | - Yun-Fei Lu
- Institute for Biomedical Sciences of Pain, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China.,Institute for Functional Brain Disorders, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China.,Key Laboratory of Brain Stress and Behavior, PLA, Xi'an, 710038, China
| | - Chun-Li Li
- Institute for Biomedical Sciences of Pain, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China.,Institute for Functional Brain Disorders, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China.,Key Laboratory of Brain Stress and Behavior, PLA, Xi'an, 710038, China
| | - Wei Sun
- Institute for Biomedical Sciences of Pain, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China.,Institute for Functional Brain Disorders, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China.,Key Laboratory of Brain Stress and Behavior, PLA, Xi'an, 710038, China
| | - Zhen Li
- Institute for Biomedical Sciences of Pain, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China.,Institute for Functional Brain Disorders, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China.,Key Laboratory of Brain Stress and Behavior, PLA, Xi'an, 710038, China
| | - Rui-Rui Wang
- Institute for Biomedical Sciences of Pain, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China.,Institute for Functional Brain Disorders, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China.,Key Laboratory of Brain Stress and Behavior, PLA, Xi'an, 710038, China
| | - Ting He
- Institute for Biomedical Sciences of Pain, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China.,Institute for Functional Brain Disorders, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China.,Key Laboratory of Brain Stress and Behavior, PLA, Xi'an, 710038, China
| | - Fan Yang
- Institute for Biomedical Sciences of Pain, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China.,Institute for Functional Brain Disorders, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China.,Key Laboratory of Brain Stress and Behavior, PLA, Xi'an, 710038, China
| | - Yan Yang
- Institute for Biomedical Sciences of Pain, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China.,Institute for Functional Brain Disorders, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China.,Key Laboratory of Brain Stress and Behavior, PLA, Xi'an, 710038, China
| | - Xiao-Liang Wang
- Institute for Biomedical Sciences of Pain, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China.,Institute for Functional Brain Disorders, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China.,Key Laboratory of Brain Stress and Behavior, PLA, Xi'an, 710038, China
| | - Su-Min Guan
- School of Stomatology, The Fourth Military Medical University, Xi'an, 710032, China
| | - Jun Chen
- Institute for Biomedical Sciences of Pain, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China.,Institute for Functional Brain Disorders, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China.,Key Laboratory of Brain Stress and Behavior, PLA, Xi'an, 710038, China.,Beijing Institute for Brain Disorders, Beijing, 100069, China
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27
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Tejada-Simon MV. Modulation of actin dynamics by Rac1 to target cognitive function. J Neurochem 2015; 133:767-79. [PMID: 25818528 DOI: 10.1111/jnc.13100] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Revised: 03/11/2015] [Accepted: 03/14/2015] [Indexed: 12/14/2022]
Abstract
The small GTPase Rac1 is well known for regulating actin cytoskeleton reorganization in cells. Formation of extensions at the surface of the cell is required for migration and even for cell invasion and metastases. Because an elevated level and hyperactivation of this protein has been associated with metastasis in cancer, direct regulators of Rac1 are currently envisioned as a potential strategy to treat certain cancers. Less research, however, has been done regarding the role of this small GTP-binding protein in brain development, where it has an important role in dendritic spine morphogenesis through the regulation of actin. Alteration of dendritic development and spinogenesis has been often associated with mental disorders. Rac1 is associated with and required for learning and the formation of memories in the brain. Rac1 appears to be dysregulated in certain neurodevelopmental disorders that present all these three alterations: mental retardation, atypical synaptic plasticity and aberrant spine morphology. Thus, to develop novel therapies for rescuing cognitive impairment, a reasonable approach might be to target this protein, Rac1, which plays a pivotal role in directing signals that regulate actin dynamics, which in turn might have an effect in spine cytoarchitecture and synaptic function. It is possible that novel drugs that regulate Rac1 activation and function could modulate actin cytoskeleton and spine dynamics, representing potential candidates to repair intellectual disability in disorders associated with spine abnormalities. Herein, we present a list of the current Rac1 inhibitors that might fulfill this role together with a summary of the latest findings concerning their function as they relate to neuronal studies. While the small GTPase Rac1 is well known for regulating actin cytoskeleton reorganization in different type of cells, it appears to be also required for learning and the formation of memories in the brain. Abnormal regulation of this protein has been associated with cognitive disabilities, atypical synaptic plasticity and abnormal morphology of dendritic spines in certain neurodevelopmental disorders. Thus, modulation of Rac1 activity using novel inhibitors might be a strategy to reestablish cognitive function.
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Affiliation(s)
- Maria V Tejada-Simon
- Department of Pharmacological and Pharmaceutical Sciences, University of Houston, Houston, Texas, USA.,Department of Biology, University of Houston, Houston, Texas, USA.,Department of Psychology, University of Houston, Houston, Texas, USA.,Biology of Behavior Institute (BoBI), University of Houston, Houston, Texas, USA
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28
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Tan AM. Dendritic spine dysgenesis in neuropathic pain. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 131:385-408. [PMID: 25744680 DOI: 10.1016/bs.pmbts.2014.12.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The failure of neuropathic pain to abate even years after trauma suggests that adverse changes to synaptic function must exist in a chronic pathological state in nociceptive pathways. The chronicity of neuropathic pain therefore underscores the importance of understanding the contribution of dendritic spines--micron-sized postsynaptic structures that represent modifiable sites of synaptic contact. Historically, dendritic spines have been of great interest to the learning and memory field. More recent evidence points to the exciting implication that abnormal dendritic spine structure following disease or injury may represent a "molecular memory" for maintaining chronic pain. Dendritic spine dysgenesis in dorsal horn neurons contributes to nociceptive hyperexcitability associated with neuropathic pain, as demonstrated in multiple pain models, i.e., spinal cord injury, peripheral nerve injury, diabetic neuropathy, and thermal burn injury. Because of the relationship between dendritic spine structure and neuronal function, a thorough investigation of dendritic spine behavior in the spinal cord is a unique opportunity to better understand the mechanisms of sensory dysfunction after injury or disease. At a conceptual level, a spinal memory mechanism that engages dendritic spine remodeling would also contribute to a broad range of intractable neurological conditions. Molecules involved in regulating dendritic spine plasticity may offer novel targets for the development of effective and durable therapies for neurological disease.
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Affiliation(s)
- Andrew Michael Tan
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut, USA; Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut, USA; Hopkins School, New Haven, Connecticut, USA.
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29
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Bandaru SP, Liu S, Waxman SG, Tan AM. Dendritic spine dysgenesis contributes to hyperreflexia after spinal cord injury. J Neurophysiol 2014; 113:1598-615. [PMID: 25505110 DOI: 10.1152/jn.00566.2014] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Hyperreflexia and spasticity are chronic complications in spinal cord injury (SCI), with limited options for safe and effective treatment. A central mechanism in spasticity is hyperexcitability of the spinal stretch reflex, which presents symptomatically as a velocity-dependent increase in tonic stretch reflexes and exaggerated tendon jerks. In this study we tested the hypothesis that dendritic spine remodeling within motor reflex pathways in the spinal cord contributes to H-reflex dysfunction indicative of spasticity after contusion SCI. Six weeks after SCI in adult Sprague-Dawley rats, we observed changes in dendritic spine morphology on α-motor neurons below the level of injury, including increased density, altered spine shape, and redistribution along dendritic branches. These abnormal spine morphologies accompanied the loss of H-reflex rate-dependent depression (RDD) and increased ratio of H-reflex to M-wave responses (H/M ratio). Above the level of injury, spine density decreased compared with below-injury spine profiles and spine distributions were similar to those for uninjured controls. As expected, there was no H-reflex hyperexcitability above the level of injury in forelimb H-reflex testing. Treatment with NSC23766, a Rac1-specific inhibitor, decreased the presence of abnormal dendritic spine profiles below the level of injury, restored RDD of the H-reflex, and decreased H/M ratios in SCI animals. These findings provide evidence for a novel mechanistic relationship between abnormal dendritic spine remodeling in the spinal cord motor system and reflex dysfunction in SCI.
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Affiliation(s)
- Samira P Bandaru
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut; and Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut
| | - Shujun Liu
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut; and Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut
| | - Stephen G Waxman
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut; and Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut
| | - Andrew M Tan
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut; and Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut
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30
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Tan AM, Waxman SG. Dendritic spine dysgenesis in neuropathic pain. Neurosci Lett 2014; 601:54-60. [PMID: 25445354 DOI: 10.1016/j.neulet.2014.11.024] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 11/12/2014] [Accepted: 11/15/2014] [Indexed: 12/20/2022]
Abstract
Neuropathic pain is a significant unmet medical need in patients with variety of injury or disease insults to the nervous system. Neuropathic pain often presents as a painful sensation described as electrical, burning, or tingling. Currently available treatments have limited effectiveness and narrow therapeutic windows for safety. More powerful analgesics, e.g., opioids, carry a high risk for chemical dependence. Thus, a major challenge for pain research is the elucidation of the mechanisms that underlie neuropathic pain and developing targeted strategies to alleviate pathological pain. The mechanistic link between dendritic spine structure and circuit function could explain why neuropathic pain is difficult to treat, since nociceptive processing pathways are adversely "hard-wired" through the reorganization of dendritic spines. Several studies in animal models of neuropathic pain have begun to reveal the functional contribution of dendritic spine dysgenesis in neuropathic pain. Previous reports have demonstrated three primary changes in dendritic spine structure on nociceptive dorsal horn neurons following injury or disease, which accompany chronic intractable pain: (I) increased density of dendritic spines, particularly mature mushroom-spine spines, (II) redistribution of spines toward dendritic branch locations close to the cell body, and (III) enlargement of the spine head diameter, which generally presents as a mushroom-shaped spine. Given the important functional implications of spine distribution, density, and shape for synaptic and neuronal function, the study of dendritic spine abnormality may provide a new perspective for investigating pain, and the identification of specific molecular players that regulate spine morphology may guide the development of more effective and long-lasting therapies.
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Affiliation(s)
- Andrew M Tan
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, CT 06510, USA; Department of Neurology and Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, CT 06516, USA.
| | - Stephen G Waxman
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, CT 06510, USA; Department of Neurology and Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, CT 06516, USA
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31
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Rau KK, Spears RC, Petruska JC. The prickly, stressful business of burn pain. Exp Neurol 2014; 261:752-6. [DOI: 10.1016/j.expneurol.2014.08.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 08/18/2014] [Accepted: 08/20/2014] [Indexed: 01/21/2023]
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