101
|
Zhang Y, Liu J, Wang X, Zhang J, Xie C. Extracellular vesicle-encapsulated microRNA-23a from dorsal root ganglia neurons binds to A20 and promotes inflammatory macrophage polarization following peripheral nerve injury. Aging (Albany NY) 2021; 13:6752-6764. [PMID: 33621204 PMCID: PMC7993670 DOI: 10.18632/aging.202532] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 09/24/2020] [Indexed: 12/12/2022]
Abstract
Extracellular vesicles (EVs) are capable of transferring microRNAs (miRNAs or miRs) between two different types of cells and also serve as vehicles for delivery of therapeutic molecules. After peripheral nerve injury, abnormal expression patterns of miRNAs have been observed in dorsal root ganglia (DRG) sensory neurons. We hypothesized that sensory neurons secrete miRs-containing EVs to communicate with macrophages. We demonstrated that miR-23a was upregulated in DRG neurons in spared nerve injury (SNI) mouse models. We also found that miR-23a was enriched in EVs released by cultured DRG neurons following capsaicin treatment. miR-23a-containing EVs were taken up into macrophages in which increased intracellular miR-23a promoted pro-inflammatory phenotype. A20 was verified as a target gene of miR-23a. Moreover, intrathecal delivery of EVs-miR-23a antagomir attenuated neuropathic hypersensitivity and reduced the number of M1 macrophages in injured DRGs by targeting A20. In conclusion, these results demonstrate that sensory neurons transfer EVs-encapsulated miR-23a to activate M1 macrophages and enhance neuropathic pain following the peripheral nerve injury. The study highlighted a new therapeutic approach to alleviate chronic neuropathic pain after nerve trauma by targeting detrimental miRNA in sensory neurons.
Collapse
Affiliation(s)
- Yamei Zhang
- Sichuan Medicine Key Laboratory of Clinical Genetics/Central Laboratory, Affiliated Hospital of Chengdu University, Chengdu 610081, P.R. China
| | - Junying Liu
- Sichuan Medicine Key Laboratory of Clinical Genetics/Central Laboratory, Affiliated Hospital of Chengdu University, Chengdu 610081, P.R. China
| | - Xin Wang
- Sichuan Medicine Key Laboratory of Clinical Genetics/Central Laboratory, Affiliated Hospital of Chengdu University, Chengdu 610081, P.R. China
| | - Jinfeng Zhang
- Department of Pediatrics, Affiliated Hospital of Chengdu University, Chengdu 610081, P.R. China
| | - Chenchen Xie
- Department of Neurology, Affiliated Hospital of Chengdu University, Chengdu 610081, P.R. China
| |
Collapse
|
102
|
Peripheral Mechanisms of Neuropathic Pain-the Role of Neuronal and Non-Neuronal Interactions and Their Implications for Topical Treatment of Neuropathic Pain. Pharmaceuticals (Basel) 2021; 14:ph14020077. [PMID: 33498496 PMCID: PMC7909513 DOI: 10.3390/ph14020077] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 01/13/2021] [Accepted: 01/16/2021] [Indexed: 12/16/2022] Open
Abstract
Neuropathic pain in humans arises as a consequence of injury or disease of somatosensory nervous system at peripheral or central level. Peripheral neuropathic pain is more common than central neuropathic pain, and is supposed to result from peripheral mechanisms, following nerve injury. The animal models of neuropathic pain show extensive functional and structural changes occurring in neuronal and non-neuronal cells in response to peripheral nerve injury. These pathological changes following damage lead to peripheral sensitization development, and subsequently to central sensitization initiation with spinal and supraspinal mechanism involved. The aim of this narrative review paper is to discuss the mechanisms engaged in peripheral neuropathic pain generation and maintenance, with special focus on the role of glial, immune, and epithelial cells in peripheral nociception. Based on the preclinical and clinical studies, interactions between neuronal and non-neuronal cells have been described, pointing out at the molecular/cellular underlying mechanisms of neuropathic pain, which might be potentially targeted by topical treatments in clinical practice. The modulation of the complex neuro-immuno-cutaneous interactions in the periphery represents a strategy for the development of new topical analgesics and their utilization in clinical settings.
Collapse
|
103
|
King CD, Boggero IA, Schulert GS, Pickerill HM, Cole S. Preliminary evidence for conserved transcriptional response to adversity in adults with temporomandibular disorder. Pain Rep 2021; 6:e874. [PMID: 33458557 PMCID: PMC7803915 DOI: 10.1097/pr9.0000000000000874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 09/25/2020] [Accepted: 10/21/2020] [Indexed: 12/02/2022] Open
Abstract
Temporomandibular disorder (TMD) is one of the most common orofacial pain conditions. Alteration in immune functioning is one promising biological mechanism underlying pain in TMD. However, there is a gap in the understanding of molecular bases contributing to altered immune functioning in these patients. OBJECTIVES In the current study, we investigated whether individuals with TMD would exhibit differential activity of 3 specific transcription factors involved in inflammatory (nuclear factor-kappa B, NF-kB), antiviral (interferon-regulatory factors, IRF), and sympathetic (cAMP response element-binding protein, CREB) processes using a promoter-based bioinformatics analysis, which is characterized as the "Conserved Transcriptional Response to Adversity." METHODS Adults with TMD (n = 19) and without (n = 17) underwent a standardized clinical examination for TMD. A blood sample was collected for genome-wide transcriptional RNA profiling. Bioinformatic analyses tested for differential prevalence of proinflammatory and antiviral transcription factor activity in core promoter sequences from all genes showing >1.2-fold differential expression in TMD vs controls. RESULTS Promoter-based bioinformatic analyses of genome-wide transcriptome profiles confirmed upregulation of genes bearing response elements for proinflammatory transcription factor (NF-kB, P = 0.002) and downregulation of genes with response elements for IRF (P = 0.037) in patients with TMD relative to controls. Results also indicated upregulated activity of CREB in patients with TMD (P = 0.08), consistent with increased activity of the sympathetic nervous system. CONCLUSION These results provide initial support that the regulation of immune pathways is altered in individuals with TMD. A shift of transcriptional resources to a proinflammatory state may be driven by psychosocial stress and contributes to symptoms associated with TMD.
Collapse
Affiliation(s)
- Christopher D. King
- Center for Understanding Pediatric Pain (CUPP), Cincinnati Children's, Cincinnati, OH, USA
- Division of Behavioral Medicine and Clinical Psychology, Cincinnati Children's, Cincinnati, OH, USA
- Orofacial Pain Center, Department of Oral Health Science, University of Kentucky College of Dentistry, Kentucky, USA
| | - Ian A. Boggero
- Department of Pediatrics, University of Cincinnati, College of Medicine, Cincinnati, OH, USA
| | - Grant S. Schulert
- Department of Pediatrics, University of Cincinnati, College of Medicine, Cincinnati, OH, USA
- Division of Rheumatology, Cincinnati Children's, Cincinnati, OH, USA
| | - Hannah M. Pickerill
- Center for Understanding Pediatric Pain (CUPP), Cincinnati Children's, Cincinnati, OH, USA
- Division of Behavioral Medicine and Clinical Psychology, Cincinnati Children's, Cincinnati, OH, USA
| | - Steve Cole
- Psychiatry and Biobehavioral Sciences and Medicine, University of California, Los Angeles, CA, USA
| |
Collapse
|
104
|
miR-223 Inhibits the Polarization and Recruitment of Macrophages via NLRP3/IL-1 β Pathway to Meliorate Neuropathic Pain. Pain Res Manag 2021; 2021:6674028. [PMID: 34408803 PMCID: PMC8367593 DOI: 10.1155/2021/6674028] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 03/23/2021] [Accepted: 07/14/2021] [Indexed: 12/15/2022]
Abstract
Background miRNA is an essential factor in neuropathic pain. However, the underlying mechanism of miRNA in neuropathic pain remains unclear. Objective To explore the potential role of miR-223 in neuropathic pain in a mice model of chronic sciatic nerve injury. Methods Mice were divided into the sham group, CCI group, CCI + Lenti-vector group, and CCI + Lenti-miR-223 group. Flow cytometry was used to detect the neuronal apoptosis and the proportion of M1/M2 macrophages in each group. Western blot was used to detect the protein expression levels of ASC, caspase-1, IL-1β, and IL-18 in each group. Luciferase activity assay detects the binding of miR-223 and NLRP3. Macrophage chemotaxis experiments verified the anti-inflammatory effect of miR-223 in vitro. Results The overexpression of miR-233 significantly reduced the neuropathic pain caused by CCI and reduced the apoptosis and inflammatory factor expression. miR-223 inhibits the expression of NLRP3 by directly binding to the 3'-untranslated region. Overexpression of miR-223 reduces the protein levels of NLRP3, ASC, caspase-1, IL-1β, and IL-18 in the spinal cord of CCI mice, increases the proportion of M2-type macrophages, and reduces the proportion of M1-type macrophages. Conclusion miR-223 may facilitate the development of neuropathic pain in CCI mice by inhibiting NLRP3-mediated neuroinflammation.
Collapse
|
105
|
Lacagnina MJ, Li J, Lorca S, Rice KC, Sullivan K, O'Callaghan JP, Grace PM. A role for neuroimmune signaling in a rat model of Gulf War Illness-related pain. Brain Behav Immun 2021; 91:418-428. [PMID: 33127584 PMCID: PMC7749855 DOI: 10.1016/j.bbi.2020.10.022] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 10/07/2020] [Accepted: 10/24/2020] [Indexed: 12/14/2022] Open
Abstract
More than a quarter of veterans of the 1990-1991 Persian Gulf War suffer from Gulf War Illness (GWI), a chronic, multi-symptom illness that commonly includes musculoskeletal pain. Exposure to a range of toxic chemicals, including sarin nerve agent, are a suspected root cause of GWI. Moreover, such chemical exposures induce a neuroinflammatory response in rodents, which has been linked to several GWI symptoms in rodents and veterans with GWI. To date, a neuroinflammatory basis for pain associated with GWI has not been investigated. Here, we evaluated development of nociceptive hypersensitivity in a model of GWI. Male Sprague Dawley rats were treated with corticosterone in the drinking water for 7 days, to mimic high physiological stress, followed by a single injection of the sarin nerve agent surrogate, diisopropyl fluorophosphate. These exposures alone were insufficient to induce allodynia. However, an additional sub-threshold challenge (a single intramuscular injection of pH 4 saline) induced long-lasting, bilateral allodynia. Such allodynia was associated with elevation of markers for activated microglia/macrophages (CD11b) and astrocytes/satellite glia (GFAP) in the lumbar dorsal spinal cord and dorsal root ganglia (DRG). Additionally, Toll-like receptor 4 (TLR4) mRNA was elevated in the lumbar dorsal spinal cord, while IL-1β and IL-6 were elevated in the lumbar dorsal spinal cord, DRG, and gastrocnemius muscle. Demonstrating a casual role for such neuroinflammatory signaling, allodynia was reversed by treatment with either minocycline, the TLR4 inhibitor (+)-naltrexone, or IL-10 plasmid DNA. Together, these results point to a role for neuroinflammation in male rats in the model of musculoskeletal pain related to GWI. Therapies that alleviate persistent immune dysregulation may be a strategy to treat pain and other symptoms of GWI.
Collapse
Affiliation(s)
- Michael J Lacagnina
- Laboratories of Neuroimmunology, Department of Symptom Research, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Jiahe Li
- Drug Design and Synthesis Section, National Institute on Alcohol Abuse and Alcoholism and National Institute on Drug Abuse, Bethesda, MD, USA
| | - Sabina Lorca
- Laboratories of Neuroimmunology, Department of Symptom Research, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Kenner C Rice
- Laboratories of Neuroimmunology, Department of Symptom Research, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Kimberly Sullivan
- Department of Environmental Health, Boston University School of Public Health, Boston, MA, USA
| | - James P O'Callaghan
- Health Effects Laboratory Division, Centers for Disease Control and Prevention National Institute for Occupational Safety and Health, Morgantown, WV, USA
| | - Peter M Grace
- Laboratories of Neuroimmunology, Department of Symptom Research, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
| |
Collapse
|
106
|
Ruel HLM, Watanabe R, Evangelista MC, Beauchamp G, Auger JP, Segura M, Steagall PV. Pain burden, sensory profile and inflammatory cytokines of dogs with naturally-occurring neuropathic pain treated with gabapentin alone or with meloxicam. PLoS One 2020; 15:e0237121. [PMID: 33253197 PMCID: PMC7703878 DOI: 10.1371/journal.pone.0237121] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 11/10/2020] [Indexed: 11/20/2022] Open
Abstract
Canine neuropathic pain (NeuP) has been poorly investigated. This study aimed to evaluate the pain burden, sensory profile and inflammatory cytokines in dogs with naturally-occurring NeuP. Twenty-nine client-owned dogs with NeuP were included in a prospective, partially masked, randomized crossover clinical trial, and treated with gabapentin/placebo/gabapentin-meloxicam or gabapentin-meloxicam/placebo/gabapentin (each treatment block of 7 days; total 21 days). Pain scores, mechanical (MNT) and electrical (ENT) nociceptive thresholds and descending noxious inhibitory controls (DNIC) were assessed at baseline, days 7, 14, and 21. DNIC was evaluated using ΔMNT (after-before conditioning stimulus). Positive or negative ΔMNT corresponded to inhibitory or facilitatory pain profiles, respectively. Pain scores were recorded using the Client Specific Outcome Measures (CSOM), Canine Brief Pain Inventory (CBPI), and short-form Glasgow Composite Measure Pain Scale (CMPS-SF). Data from baseline were compared to those of sixteen healthy controls. ΔMNT, but not MNT and ENT, was significantly larger in controls (2.3 ± 0.9 N) than in NeuP (-0.2 ± 0.7 N). The percentage of dogs with facilitatory sensory profile was similar at baseline and after placebo (61.5–63%), and between controls and after gabapentin (33.3–34.6%). The CBPI scores were significantly different between gabapentin (CBPI pain and CBPI overall impression) and/or gabapentin-meloxicam (CBPI pain and interference) when compared with baseline, but not placebo. The CBPI scores were not significantly different between placebo and baseline. The concentration of cytokines was not different between groups or treatments. Dogs with NeuP have deficient inhibitory pain mechanisms. Pain burden was reduced after gabapentin and/or gabapentin-meloxicam when compared with baseline using CBPI and CMPS-SF scores. However, these scores were not superior than placebo, nor placebo was superior to baseline evaluations. A caregiver placebo effect may have biased the results.
Collapse
Affiliation(s)
- Hélène L. M. Ruel
- Department of Clinical Sciences, Faculté de médecine vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec, Canada
| | - Ryota Watanabe
- Department of Clinical Sciences, Faculté de médecine vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec, Canada
| | - Marina C. Evangelista
- Department of Clinical Sciences, Faculté de médecine vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec, Canada
| | - Guy Beauchamp
- Faculté de médecine vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec, Canada
| | - Jean-Philippe Auger
- Research Group on Infectious Diseases in Production Animals (GREMIP) and Swine and Poultry Infectious Diseases Research Centre (CRIPA), Faculté de médecine vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec, Canada
| | - Mariela Segura
- Research Group on Infectious Diseases in Production Animals (GREMIP) and Swine and Poultry Infectious Diseases Research Centre (CRIPA), Faculté de médecine vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec, Canada
| | - Paulo V. Steagall
- Department of Clinical Sciences, Faculté de médecine vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec, Canada
- * E-mail:
| |
Collapse
|
107
|
The Neuroimmunology of Chronic Pain: From Rodents to Humans. J Neurosci 2020; 41:855-865. [PMID: 33239404 DOI: 10.1523/jneurosci.1650-20.2020] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 09/29/2020] [Accepted: 10/04/2020] [Indexed: 12/11/2022] Open
Abstract
Chronic pain, encompassing conditions, such as low back pain, arthritis, persistent post-surgical pain, fibromyalgia, and neuropathic pain disorders, is highly prevalent but remains poorly treated. The vast majority of therapeutics are directed solely at neurons, despite the fact that signaling between immune cells, glia, and neurons is now recognized as indispensable for the initiation and maintenance of chronic pain. This review highlights recent advances in understanding fundamental neuroimmune signaling mechanisms and novel therapeutic targets in rodent models of chronic pain. We further discuss new technological developments to study, diagnose, and quantify neuroimmune contributions to chronic pain in patient populations.
Collapse
|
108
|
Huang SS, Cao S, Lu CE, Qin YB, Yang JP. Effects of nicorandil on p120 expression in the spinal cord and dorsal root ganglion of rats with chronic postsurgical pain. Mol Med Rep 2020; 22:4821-4827. [PMID: 33173987 PMCID: PMC7646919 DOI: 10.3892/mmr.2020.11546] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 08/21/2020] [Indexed: 01/25/2023] Open
Abstract
Chronic postsurgical pain (CPSP) has a high incidence, but the underlying mechanism is not well understood. Accumulating evidence has suggested that central sensitization is the main mechanism of pain. To study the role of p120 in CPSP, a skin/muscle incision and retraction (SMIR) model was established, and immunofluorescence staining and western blotting were performed to analyze the expression of p120 in the spinal cord and dorsal root ganglion (DRG). The results demonstrated that SMIR increased the expression of p120 in the DRG and the spinal cord compared with the naive group. Furthermore, it was demonstrated that p120 was mainly distributed in the glial fibrillary acidic protein-positive astrocytes in the spinal cord, and in the neurofilament 200-positive medium and large neurons in the DRG. Our previous studies have shown that adenosine triphosphate-sensitive potassium channel (KATP) agonists can reduce postoperative pain in rats. Therefore, the changes in p120 were observed in the DRG and spinal cord of rats following the intraperitoneal injection of nicorandil, a KATP agonist. It was demonstrated that nicorandil administration could relieve mechanical pain experienced following SMIR in rats, and decrease the expression of p120 in the DRG and spinal cord. The results revealed that p120 may contribute to the prophylactic analgesic effect of nicorandil, thus providing a novel insight into the mechanism of CPSP prevention.
Collapse
Affiliation(s)
- Sai-Sai Huang
- Department of Anesthesiology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215000, P.R. China
| | - Su Cao
- Department of Anesthesiology, Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, P.R. China
| | - Cui E Lu
- Department of Anesthesiology, Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, P.R. China
| | - Yi-Bin Qin
- Department of Anesthesiology, Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, P.R. China
| | - Jian-Ping Yang
- Department of Anesthesiology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215000, P.R. China
| |
Collapse
|
109
|
Wang J, Zheng X, Liu B, Yin C, Chen R, Li X, Li Y, Nie H, Zeng D, He X, Jiang Y, Fang J, Liu B. Electroacupuncture Alleviates Mechanical Allodynia of a Rat Model of CRPS-I and Modulates Gene Expression Profiles in Dorsal Root Ganglia. Front Neurol 2020; 11:580997. [PMID: 33193035 PMCID: PMC7661737 DOI: 10.3389/fneur.2020.580997] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 09/30/2020] [Indexed: 12/19/2022] Open
Abstract
Complex regional pain syndrome type-I (CRPS-I) is chronic neurological disorder accompanied with devastating pain. Most conventional medical treatments lack effectiveness, making CRPS-I a challenging clinical condition. Electroacupuncture (EA) showed effectiveness in alleviating the pain symptoms of CRPS-I patients. However, the molecular mechanisms underlying EA's therapeutic effect are still not well-understood. Here, we established the rat chronic post-ischemic pain (CPIP) model to mimic CRPS-I and performed repetitive EA on bilateral hind limbs of the CPIP model rats. We then performed RNA-sequencing (RNA-Seq) to study the differences in gene expression, gene networks, and molecular pathways in ipsilateral DRGs innervating the hind limb of the CPIP model rats with and without repetitive EA treatment. Our results found that repetitive EA treatment significantly alleviated mechanical allodynia in bilateral hind limbs of CPIP model rats. RNA-Seq analysis indicated that EA modulated the expression of multiple genes and gene networks in the DRGs of CPIP model rats. Further bioinformatics analysis identified the up-regulation of an array of genes involved in biological process such as neutrophil chemotaxis and immune response in the DRGs of CPIP model rats after EA treatment. Thus, these results suggest that EA may alleviate pain response in CPIP model rats via regulating multiple genes. Our work may help to further advance the understandings of the molecular mechanisms underlying EA's therapeutic effects on CRPS-I and help to identify novel targets for CRPS-I treatment.
Collapse
Affiliation(s)
- Jie Wang
- Key Laboratory of Acupuncture and Neurology of Zhejiang Province, Department of Neurobiology and Acupuncture Research, The Third Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, China
| | - Xiaoli Zheng
- Key Laboratory of Acupuncture and Neurology of Zhejiang Province, Department of Neurobiology and Acupuncture Research, The Third Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, China
| | - Boyu Liu
- Key Laboratory of Acupuncture and Neurology of Zhejiang Province, Department of Neurobiology and Acupuncture Research, The Third Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, China
| | - Chengyu Yin
- Key Laboratory of Acupuncture and Neurology of Zhejiang Province, Department of Neurobiology and Acupuncture Research, The Third Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, China
| | - Ruixiang Chen
- Key Laboratory of Acupuncture and Neurology of Zhejiang Province, Department of Neurobiology and Acupuncture Research, The Third Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, China
| | - Xiaojie Li
- Key Laboratory of Acupuncture and Neurology of Zhejiang Province, Department of Neurobiology and Acupuncture Research, The Third Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, China
| | - Yuanyuan Li
- Key Laboratory of Acupuncture and Neurology of Zhejiang Province, Department of Neurobiology and Acupuncture Research, The Third Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, China
| | - Huimin Nie
- Key Laboratory of Acupuncture and Neurology of Zhejiang Province, Department of Neurobiology and Acupuncture Research, The Third Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, China
| | - Danyi Zeng
- Key Laboratory of Acupuncture and Neurology of Zhejiang Province, Department of Neurobiology and Acupuncture Research, The Third Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, China
| | - Xiaofen He
- Key Laboratory of Acupuncture and Neurology of Zhejiang Province, Department of Neurobiology and Acupuncture Research, The Third Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, China
| | - Yongliang Jiang
- Key Laboratory of Acupuncture and Neurology of Zhejiang Province, Department of Neurobiology and Acupuncture Research, The Third Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, China
| | - Jianqiao Fang
- Key Laboratory of Acupuncture and Neurology of Zhejiang Province, Department of Neurobiology and Acupuncture Research, The Third Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, China
| | - Boyi Liu
- Key Laboratory of Acupuncture and Neurology of Zhejiang Province, Department of Neurobiology and Acupuncture Research, The Third Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, China
| |
Collapse
|
110
|
Conti PCR, Bonjardim LR, Stuginski-Barbosa J, Costa YM, Svensson P. Pain complications of oral implants: Is that an issue? J Oral Rehabil 2020; 48:195-206. [PMID: 33047362 DOI: 10.1111/joor.13112] [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: 06/29/2020] [Revised: 09/08/2020] [Accepted: 10/05/2020] [Indexed: 01/03/2023]
Abstract
The use of oral implants as a form of replacing missing teeth in partial or total edentulous patients is considered the gold standard in oral rehabilitation. Although considered a history of success in contemporary dentistry, surgical complications may occur, as excessive bleeding, damage to the adjacent teeth and mandibular fractures. Persistent pain and abnormal somatosensory responses after the surgery ordinary healing time are also potential problems and may lead to the development of a condition named posttraumatic trigeminal neuropathic pain (PTNP). Though relatively rare, PTNP has a profound impact on patient's quality of life. Appropriated previous image techniques, effective anaesthetic procedures and caution during the surgical procedure and implant installation are recommended for the prevention of this condition. In case of the PTNP, different management modalities, including antidepressant and membrane stabilizer medications, as well as peripheral strategies, as the use of topical medication and the botulin toxin are presented and discussed.
Collapse
Affiliation(s)
- Paulo César Rodrigues Conti
- Department of Prosthodontics, Bauru School of Dentistry, University of São Paulo, Brazil.,Bauru Orofacial Pain Group, University of São Paulo, Bauru, Brazil
| | - Leonardo Rigoldi Bonjardim
- Section of Head and Face Physiology, Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, Brazil.,Department of Biosciences, Piracicaba Dental School, University of Campinas, Piracicaba, Brazil
| | | | - Yuri Martins Costa
- Bauru Orofacial Pain Group, University of São Paulo, Bauru, Brazil.,Department of Biosciences, Piracicaba Dental School, University of Campinas, Piracicaba, Brazil
| | - Peter Svensson
- Section of Orofacial Pain and Jaw Function, Department of Dentistry and Oral Health, Aarhus University, Aarhus, Denmark.,Department of Orofacial Pain and Jaw Function, Faculty of Odontology, Malmø University, Malmø, Sweden.,Scandinavian Center for Orofacial Neurosciences (SCON)
| |
Collapse
|
111
|
Abstract
AbstractPain is a challenge to rheumatologists. Not only patients with active arthritis
but also patients with a good therapeutic response and even in remission
complain of persistent joint pain. It has been proposed that a chronic pain
stimulus may have a greater impact in a chronic inflammatory state, and the
process towards a pain condition may be influenced by individual predisposition
for development of chronic pain. In addition, features of peripheral pain
processing may be exacerbated by inflammation, and disturbed pain processing may
be a feature contributing to widespread pain. Furthermore, a neuropathic
component may be part of the total pain experience of our patients. There are
many different strategies of pain therapy in patients with rheumatic diseases,
such as pharmacological and non- pharmacological modalities.
Collapse
Affiliation(s)
- Olga Seifert
- Abteilung für Rheumatologie, Medizinische Klinik III,
Universitätskliniken Leipzig, Leipzig
| | - Christoph Baerwald
- Abteilung für Rheumatologie, Medizinische Klinik III,
Universitätskliniken Leipzig, Leipzig
| |
Collapse
|
112
|
Cappoli N, Tabolacci E, Aceto P, Dello Russo C. The emerging role of the BDNF-TrkB signaling pathway in the modulation of pain perception. J Neuroimmunol 2020; 349:577406. [PMID: 33002723 DOI: 10.1016/j.jneuroim.2020.577406] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 09/15/2020] [Accepted: 09/22/2020] [Indexed: 02/07/2023]
Abstract
The brain derived neurotrophic factor (BDNF) is a crucial neuromodulator in pain transmission both in peripheral and central nervous system (CNS). Despite evidence of a pro-nociceptive role of BDNF, recent studies have reported contrasting results, including anti-nociceptive and anti-inflammatory activities. Moreover, BDNF polymorphisms can interfere with BDNF role in pain perception. In Val66Met carriers, the Met allele may have a dual role, with anti-nociceptive actions in normal condition and pro-nociceptive effects during chronic pain. In order to elucidate the main effects of BDNF in nociception, we reviewed the main characteristics of this neurotrophin, focusing on its involvement in pain.
Collapse
Affiliation(s)
- Natalia Cappoli
- Università Cattolica del Sacro Cuore, Dipartimento di Sicurezza e Bioetica, Sezione di Farmacologia, Rome, Italy
| | - Elisabetta Tabolacci
- Università Cattolica del Sacro Cuore, Dipartimento di Scienze della Vita e Sanità Pubblica, Sezione di Medicina Genomica, Rome, Italy; Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | - Paola Aceto
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Dipartimento di Scienze dell'Emergenza, Anestesiologiche e della Rianimazione, Rome, Italy; Università Cattolica del Sacro Cuore, Dipartimento di Scienze biotecnologiche di base, cliniche intensivologiche e perioperatorie, Rome, Italy.
| | - Cinzia Dello Russo
- Università Cattolica del Sacro Cuore, Dipartimento di Sicurezza e Bioetica, Sezione di Farmacologia, Rome, Italy; Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| |
Collapse
|
113
|
|
114
|
Allen BL, Montague-Cardoso K, Simeoli R, Colas RA, Oggero S, Vilar B, McNaughton PA, Dalli J, Perretti M, Sher E, Malcangio M. Imbalance of proresolving lipid mediators in persistent allodynia dissociated from signs of clinical arthritis. Pain 2020; 161:2155-2166. [PMID: 32379221 PMCID: PMC7431142 DOI: 10.1097/j.pain.0000000000001908] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 04/23/2020] [Indexed: 12/15/2022]
Abstract
ABSTRACT Rheumatoid arthritis-associated pain is poorly managed, often persisting when joint inflammation is pharmacologically controlled. Comparably, in the mouse K/BxN serum-transfer model of inflammatory arthritis, hind paw nociceptive hypersensitivity occurs with ankle joint swelling (5 days after immunisation) persisting after swelling has resolved (25 days after immunisation). In this study, lipid mediator (LM) profiling of lumbar dorsal root ganglia (DRG), the site of sensory neuron cell bodies innervating the ankle joints, 5 days and 25 days after serum transfer demonstrated a shift in specialised proresolving LM profiles. Persistent nociception without joint swelling was associated with low concentrations of the specialised proresolving LM Maresin 1 (MaR1) and high macrophage numbers in DRG. MaR1 application to cultured DRG neurons inhibited both capsaicin-induced increase of intracellular calcium ions and release of calcitonin gene-related peptide in a dose-dependent manner. Furthermore, in peritoneal macrophages challenged with lipopolysaccharide, MaR1 reduced proinflammatory cytokine expression. Systemic MaR1 administration caused sustained reversal of nociceptive hypersensitivity and reduced inflammatory macrophage numbers in DRG. Unlike gabapentin, which was used as positive control, systemic MaR1 did not display acute antihyperalgesic action. Therefore, these data suggest that MaR1 effects observed after K/BxN serum transfer relate to modulation of macrophage recruitment, more likely than to direct actions on sensory neurons. Our study highlights that, in DRG, aberrant proresolution mechanisms play a key role in arthritis joint pain dissociated from joint swelling, opening novel approaches for rheumatoid arthritis pain treatment.
Collapse
Affiliation(s)
- Benjamin L Allen
- Wolfson Centre for Age Related Diseases, King's College London, London, United Kingdom
| | | | - Raffaele Simeoli
- Wolfson Centre for Age Related Diseases, King's College London, London, United Kingdom
- Laboratory of Metabolic Biochemistry Unit, Department of Pediatric Medicine, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Romain A Colas
- Barts and The London School of Medicine, The William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Silvia Oggero
- Barts and The London School of Medicine, The William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Bruno Vilar
- Wolfson Centre for Age Related Diseases, King's College London, London, United Kingdom
| | - Peter A McNaughton
- Wolfson Centre for Age Related Diseases, King's College London, London, United Kingdom
| | - Jesmond Dalli
- Barts and The London School of Medicine, The William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Mauro Perretti
- Barts and The London School of Medicine, The William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Emanuele Sher
- Neuroscience Discovery, Lilly Research Centre, Eli Lilly and Company Ltd, Surrey, United Kingdom
| | - Marzia Malcangio
- Wolfson Centre for Age Related Diseases, King's College London, London, United Kingdom
| |
Collapse
|
115
|
Gao Y, Bai L, Zhou W, Yang Y, Zhang J, Li L, Jiang M, Mi Y, Li TT, Zhang X, Zhang W, Xu JT. PARP-1-regulated TNF-α expression in the dorsal root ganglia and spinal dorsal horn contributes to the pathogenesis of neuropathic pain in rats. Brain Behav Immun 2020; 88:482-496. [PMID: 32283287 DOI: 10.1016/j.bbi.2020.04.019] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 04/08/2020] [Accepted: 04/09/2020] [Indexed: 01/04/2023] Open
Abstract
Emerging evidence has implicated poly-(ADP-ribose) polymerase 1 (PARP-1), a transcriptional coregulator, in a variety of inflammatory diseases. In the current study, the role of PARP-1 in neuropathic pain and the underlying mechanisms were investigated. Neuropathic pain was determined by assessing the paw withdrawal threshold (PWT) and paw withdrawal latency (PWL) following lumbar 5 spinal nerve ligation (SNL) in male rates. Western blotting, qRT-PCR, immunohistochemistry, chromatin immunoprecipitation (ChIP), and Co-IP assays were performed to elucidate the mechanisms. The results showed that SNL resulted in a significant increase in the expression and activation of PARP-1 in the ipsilateral L4/5 dorsal root ganglia (DRG) and spinal dorsal horn, which occurred on day one, reached peak on day 7, and persisted more than 2 weeks after surgery. Double immunofluorescence staining revealed that PARP-1 was expressed exclusively in DRG A-type and C-type neurons. In the spinal cord, PARP-1 mainly colocalized with the neuronal marker NeuN and the astrocytic marker GFAP specifically in the superficial lamina. Prior intrathecal (i.t.) injection of PJ-34, a PARPs inhibitor, or Tiq-A, a specific PARP-1 inhibitor, dose-dependently prevented the reductions in PWT and PWL following SNL. Established neuropathic pain-like hypersensitivity was also attenuated with i.t. injection of PJ-34 and Tiq-A starting on day 7 following SNL, a timepoint at which neuropathic pain was fully established. SNL-induced mechanical allodynia and thermal hyperalgesia were also alleviated by i.t. injection of PARP-1 siRNA following a reduction in PARP-1 expression in the dorsal horn. Moreover, the SNL-induced increases in TNF-α protein and mRNA in the dorsal horn and DRG were dramatically suppressed by i.t. injection of Tiq-A or PARP-1 siRNA. The i.t. lipopolysaccharide (LPS)-induced increase in the production of TNF-α in the dorsal horn was also inhibited by prior to i.t. injection of PARP-1 siRNA. Results of ChIP assay showed that SNL-induced PARP-1 activation promoted the binding of NF-κB p65 with the TNF-α promoter in the dorsal horn and that PARP-1 inhibition reduced this binding and suppressed TNF-α expression. Co-IP assay revealed that SNL caused a significant increase in the level of histone H1 poly(ADP)-ribosylation. Together, these results indicate that PARP-1-regulated TNF-α expression in the DRG and spinal dorsal horn following SNL contributes to the development and maintenance of neuropathic pain. Targeting PARP-1 might be a promising therapeutic strategy for the treatment of the chronic pain.
Collapse
Affiliation(s)
- Yan Gao
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, 100 Science Avenue, Zhengzhou 450001, China
| | - Liying Bai
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, 100 Science Avenue, Zhengzhou 450001, China; Department of Anesthesiology, Pain and Perioperative Medicine, The First Affiliated Hospital, Zhengzhou University, 1 Jianshe East Road, Zhengzhou 450052, China
| | - Wenjuan Zhou
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, 100 Science Avenue, Zhengzhou 450001, China; Department of Anesthesiology, Pain and Perioperative Medicine, The First Affiliated Hospital, Zhengzhou University, 1 Jianshe East Road, Zhengzhou 450052, China
| | - Yin Yang
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, 100 Science Avenue, Zhengzhou 450001, China
| | - Jian Zhang
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, 100 Science Avenue, Zhengzhou 450001, China
| | - Liren Li
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, 100 Science Avenue, Zhengzhou 450001, China
| | - Mingjun Jiang
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, 100 Science Avenue, Zhengzhou 450001, China
| | - Yang Mi
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, 100 Science Avenue, Zhengzhou 450001, China
| | - Tong-Tong Li
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, 100 Science Avenue, Zhengzhou 450001, China
| | - Xuan Zhang
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, 100 Science Avenue, Zhengzhou 450001, China
| | - Wei Zhang
- Department of Anesthesiology, Pain and Perioperative Medicine, The First Affiliated Hospital, Zhengzhou University, 1 Jianshe East Road, Zhengzhou 450052, China
| | - Ji-Tian Xu
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, 100 Science Avenue, Zhengzhou 450001, China; Neuroscience Research Institute, Zhengzhou University, 100 Science Avenue, Zhengzhou 450001, China.
| |
Collapse
|
116
|
Temporal arteritis, Sjögren's syndrome and mixed pain components as manifestations in a diabetic older adult: systematic review based on a case report. Reumatologia 2020; 58:179-183. [PMID: 32684652 PMCID: PMC7362268 DOI: 10.5114/reum.2020.96684] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Accepted: 06/02/2020] [Indexed: 12/11/2022] Open
Abstract
Temporal arteritis (TA) is an inflammatory vascular disease common in the European population. It is mainly characterized by sudden onset headache. TA is rarely associated with other autoimmune diseases, such as Sjögren's syndrome (SS). We present the case of a Peruvian 71 year-old man with SS history, who was admitted to the emergency department due to severe headache evolved in 4 days, periocular pain and right ptosis. The authors also performed a systematic review of case reports or case series of patients diagnosed with both TA and SS. This temporal arteritis case is an atypical presentation because headache was characterized by mixed nociceptive and neuropathic pain components. Despite the infrequency, new studies should be carried out to identify comorbidities in TA patients.
Collapse
|
117
|
Chambel SS, Tavares I, Cruz CD. Chronic Pain After Spinal Cord Injury: Is There a Role for Neuron-Immune Dysregulation? Front Physiol 2020; 11:748. [PMID: 32733271 PMCID: PMC7359877 DOI: 10.3389/fphys.2020.00748] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 06/08/2020] [Indexed: 12/14/2022] Open
Abstract
Spinal cord injury (SCI) is a devastating event with a tremendous impact in the life of the affected individual and family. Traumatic injuries related to motor vehicle accidents, falls, sports, and violence are the most common causes. The majority of spinal lesions is incomplete and occurs at cervical levels of the cord, causing a disruption of several ascending and descending neuronal pathways. Additionally, many patients develop chronic pain and describe it as burning, stabbing, shooting, or shocking and often arising with no stimulus. Less frequently, people with SCI also experience pain out of context with the stimulus (e.g., light touch). While abolishment of the endogenous descending inhibitory circuits is a recognized cause for chronic pain, an increasing number of studies suggest that uncontrolled release of pro- and anti-inflammatory mediators by neurons, glial, and immune cells is also important in the emergence and maintenance of SCI-induced chronic pain. This constitutes the topic of the present mini-review, which will focus on the importance of neuro-immune dysregulation for pain after SCI.
Collapse
Affiliation(s)
- Sílvia S Chambel
- Department of Biomedicine, Experimental Biology Unit, Faculty of Medicine, University of Porto, Porto, Portugal.,Translational NeuroUrology Group, Instituto de Investigação e Inovação em Saúde - i3S, Universidade do Porto, Porto, Portugal
| | - Isaura Tavares
- Department of Biomedicine, Experimental Biology Unit, Faculty of Medicine, University of Porto, Porto, Portugal.,Pain Research Group, Instituto de Investigação e Inovação em Saúde - i3S, Universidade do Porto, Porto, Portugal
| | - Célia D Cruz
- Department of Biomedicine, Experimental Biology Unit, Faculty of Medicine, University of Porto, Porto, Portugal.,Translational NeuroUrology Group, Instituto de Investigação e Inovação em Saúde - i3S, Universidade do Porto, Porto, Portugal
| |
Collapse
|
118
|
Type I Interferons Act Directly on Nociceptors to Produce Pain Sensitization: Implications for Viral Infection-Induced Pain. J Neurosci 2020; 40:3517-3532. [PMID: 32245829 DOI: 10.1523/jneurosci.3055-19.2020] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Revised: 03/04/2020] [Accepted: 03/19/2020] [Indexed: 12/25/2022] Open
Abstract
One of the first signs of viral infection is body-wide aches and pain. Although this type of pain usually subsides, at the extreme, viral infections can induce painful neuropathies that can last for decades. Neither of these types of pain sensitization is well understood. A key part of the response to viral infection is production of interferons (IFNs), which then activate their specific receptors (IFNRs) resulting in downstream activation of cellular signaling and a variety of physiological responses. We sought to understand how type I IFNs (IFN-α and IFN-β) might act directly on nociceptors in the dorsal root ganglion (DRG) to cause pain sensitization. We demonstrate that type I IFNRs are expressed in small/medium DRG neurons and that their activation produces neuronal hyper-excitability and mechanical pain in mice. Type I IFNs stimulate JAK/STAT signaling in DRG neurons but this does not apparently result in PKR-eIF2α activation that normally induces an anti-viral response by limiting mRNA translation. Rather, type I IFNs stimulate MNK-mediated eIF4E phosphorylation in DRG neurons to promote pain hypersensitivity. Endogenous release of type I IFNs with the double-stranded RNA mimetic poly(I:C) likewise produces pain hypersensitivity that is blunted in mice lacking MNK-eIF4E signaling. Our findings reveal mechanisms through which type I IFNs cause nociceptor sensitization with implications for understanding how viral infections promote pain and can lead to neuropathies.SIGNIFICANCE STATEMENT It is increasingly understood that pathogens interact with nociceptors to alert organisms to infection as well as to mount early host defenses. Although specific mechanisms have been discovered for diverse bacterial and fungal pathogens, mechanisms engaged by viruses have remained elusive. Here we show that type I interferons, one of the first mediators produced by viral infection, act directly on nociceptors to produce pain sensitization. Type I interferons act via a specific signaling pathway (MNK-eIF4E signaling), which is known to produce nociceptor sensitization in inflammatory and neuropathic pain conditions. Our work reveals a mechanism through which viral infections cause heightened pain sensitivity.
Collapse
|
119
|
Kalpachidou T, Kummer K, Kress M. Non-coding RNAs in neuropathic pain. Neuronal Signal 2020; 4:NS20190099. [PMID: 32587755 PMCID: PMC7306520 DOI: 10.1042/ns20190099] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 03/31/2020] [Accepted: 04/02/2020] [Indexed: 02/07/2023] Open
Abstract
Neuro-immune alterations in the peripheral and central nervous system play a role in the pathophysiology of chronic pain in general, and members of the non-coding RNA (ncRNA) family, specifically the short, 22 nucleotide microRNAs (miRNAs) and the long non-coding RNAs (lncRNAs) act as master switches orchestrating both immune as well as neuronal processes. Several chronic disorders reveal unique ncRNA expression signatures, which recently generated big hopes for new perspectives for the development of diagnostic applications. lncRNAs may offer perspectives as candidates indicative of neuropathic pain in liquid biopsies. Numerous studies have provided novel mechanistic insight into the role of miRNAs in the molecular sequelae involved in the pathogenesis of neuropathic pain along the entire pain pathway. Specific processes within neurons, immune cells, and glia as the cellular components of the neuropathic pain triad and the communication paths between them are controlled by specific miRNAs. Therefore, nucleotide sequences mimicking or antagonizing miRNA actions can provide novel therapeutic strategies for pain treatment, provided their human homologues serve the same or similar functions. Increasing evidence also sheds light on the function of lncRNAs, which converge so far mainly on purinergic signalling pathways both in neurons and glia, and possibly even other ncRNA species that have not been explored so far.
Collapse
Affiliation(s)
| | - Kai K. Kummer
- Institute of Physiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Michaela Kress
- Institute of Physiology, Medical University of Innsbruck, Innsbruck, Austria
| |
Collapse
|