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Fiore NT, Hayes JP, Williams SI, Moalem-Taylor G. Interleukin-35 alleviates neuropathic pain and induces an anti-inflammatory shift in spinal microglia in nerve-injured male mice. Brain Behav Immun 2024; 122:287-300. [PMID: 39097202 DOI: 10.1016/j.bbi.2024.07.043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2024] [Revised: 07/25/2024] [Accepted: 07/28/2024] [Indexed: 08/05/2024] Open
Abstract
Immune cells are critical in promoting neuroinflammation and neuropathic pain and in facilitating pain resolution, depending on their inflammatory and immunoregulatory cytokine response. Interleukin (IL)-35, secreted by regulatory immune cells, is a member of the IL-12 family with a potent immunosuppressive function. In this study, we investigated the effects of IL-35 on pain behaviors, spinal microglia phenotype following peripheral nerve injury, and in vitro microglial cultures in male and female mice. Intrathecal recombinant IL-35 treatment alleviated mechanical pain hypersensitivity prominently in male mice, with only a modest effect in female mice after sciatic nerve chronic constriction injury (CCI). IL-35 treatment resulted in sex-specific microglial changes following CCI, reducing inflammatory microglial markers and upregulating anti-inflammatory markers in male mice. Spatial transcriptomic analysis revealed that IL-35 suppressed microglial complement activation in the superficial dorsal horn in male mice after CCI. Moreover, in vitro studies showed that IL-35 treatment of cultured inflammatory microglia mitigated their hypertrophied morphology, increased their cell motility, and decreased their phagocytic activity, indicating a phenotypic shift towards homeostatic microglia. Further, IL-35 altered microglial cytokines/chemokines in vitro, suppressing the release of IL-9 and monocyte-chemoattractant protein-1 and increasing IL-10 in the supernatant of male microglial cultures. Our findings indicate that treatment with IL-35 modulates spinal microglia and alleviates neuropathic pain in male mice, suggesting IL-35 as a potential sex-specific targeted immunomodulatory treatment for neuropathic pain.
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Affiliation(s)
- Nathan T Fiore
- Translational Neuroscience Facility, Department of Physiology, School of Biomedical Sciences, University of New South Wales, UNSW Sydney, NSW, Australia
| | - Jessica P Hayes
- Translational Neuroscience Facility, Department of Physiology, School of Biomedical Sciences, University of New South Wales, UNSW Sydney, NSW, Australia
| | - Sarah I Williams
- Translational Neuroscience Facility, Department of Physiology, School of Biomedical Sciences, University of New South Wales, UNSW Sydney, NSW, Australia
| | - Gila Moalem-Taylor
- Translational Neuroscience Facility, Department of Physiology, School of Biomedical Sciences, University of New South Wales, UNSW Sydney, NSW, Australia.
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2
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Smith PA. Neuropathic pain; what we know and what we should do about it. FRONTIERS IN PAIN RESEARCH 2023; 4:1220034. [PMID: 37810432 PMCID: PMC10559888 DOI: 10.3389/fpain.2023.1220034] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 09/05/2023] [Indexed: 10/10/2023] Open
Abstract
Neuropathic pain can result from injury to, or disease of the nervous system. It is notoriously difficult to treat. Peripheral nerve injury promotes Schwann cell activation and invasion of immunocompetent cells into the site of injury, spinal cord and higher sensory structures such as thalamus and cingulate and sensory cortices. Various cytokines, chemokines, growth factors, monoamines and neuropeptides effect two-way signalling between neurons, glia and immune cells. This promotes sustained hyperexcitability and spontaneous activity in primary afferents that is crucial for onset and persistence of pain as well as misprocessing of sensory information in the spinal cord and supraspinal structures. Much of the current understanding of pain aetiology and identification of drug targets derives from studies of the consequences of peripheral nerve injury in rodent models. Although a vast amount of information has been forthcoming, the translation of this information into the clinical arena has been minimal. Few, if any, major therapeutic approaches have appeared since the mid 1990's. This may reflect failure to recognise differences in pain processing in males vs. females, differences in cellular responses to different types of injury and differences in pain processing in humans vs. animals. Basic science and clinical approaches which seek to bridge this knowledge gap include better assessment of pain in animal models, use of pain models which better emulate human disease, and stratification of human pain phenotypes according to quantitative assessment of signs and symptoms of disease. This can lead to more personalized and effective treatments for individual patients. Significance statement: There is an urgent need to find new treatments for neuropathic pain. Although classical animal models have revealed essential features of pain aetiology such as peripheral and central sensitization and some of the molecular and cellular mechanisms involved, they do not adequately model the multiplicity of disease states or injuries that may bring forth neuropathic pain in the clinic. This review seeks to integrate information from the multiplicity of disciplines that seek to understand neuropathic pain; including immunology, cell biology, electrophysiology and biophysics, anatomy, cell biology, neurology, molecular biology, pharmacology and behavioral science. Beyond this, it underlines ongoing refinements in basic science and clinical practice that will engender improved approaches to pain management.
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Affiliation(s)
- Peter A. Smith
- Neuroscience and Mental Health Institute and Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
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3
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Yang F, Jing JJ, Fu SY, Su XZ, Zhong YL, Chen DS, Wu XZ, Zou YQ. Spinal MCP-1 Contributes to Central Post-stroke Pain by Inducing Central Sensitization in Rats. Mol Neurobiol 2023; 60:2086-2098. [PMID: 36602702 DOI: 10.1007/s12035-022-03184-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 12/18/2022] [Indexed: 01/06/2023]
Abstract
Central post-stroke pain (CPSP) is a highly refractory form of central neuropathic pain that has been poorly studied mechanistically. Recent observations have emphasized the critical role of the spinal dorsal horn in CPSP. However, the underlying mechanisms remain unclear. In this study, rats were subjected to thalamic hemorrhage to investigate the role of spinal monocyte chemoattractant protein-1 (MCP-1) and C-C motif chemokine receptor 2 (CCR2) in the development of CPSP. Immunohistochemical staining and ELISA were used to assess the expression changes of c-Fos, Iba-1, GFAP, MCP-1, and CCR2 in the dorsal horn of the lumbar spinal cord following thalamic hemorrhage, and the involvement of spinal MCP-1 in CPSP was examined by performing intrathecal anti-MCP-1 mAb injection to neutralize the spinal extracellular MCP-1. We demonstrated that intra-thalamic collagenase microinjection induced persistent bilateral mechanical pain hypersensitivity and facilitated the spontaneous pain behaviors evoked by intraplantar bee venom injection. Accompanying CPSP, the expression of c-Fos, Iba-1, and GFAP in the lumbar spinal dorsal horn was significantly increased up to 28 days post-intra-thalamic collagenase microinjection. Intrathecal injection of minocycline and fluorocitrate dramatically reverses the bilateral mechanical pain hypersensitivity. Moreover, intra-thalamic collagenase microinjection dramatically induced the up-regulation of MCP-1 but had no effect on the expression of CCR2 in the bilateral lumbar spinal dorsal horn, and MCP-1 was primarily localized in the neuron. Intrathecal injection of anti-MCP-1 mAb was also able to reverse CPSP and reduce the expression of c-Fos, Iba-1, and GFAP in the lumbar spinal dorsal horn. These findings indicated that spinal MCP-1 contributes to CPSP by mediating the activation of spinal neurons and glial cells following thalamic hemorrhage stroke, which may provide insights into pharmacologic treatment for CPSP.
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Affiliation(s)
- Fei Yang
- Department of Anesthesiology and Perioperative Medicine, Fuzong Clinical College/900th Hospital of the Joint Logistic Support Force, Fujian Medical University, Fuzhou, 350025, China.,Department of Anesthesiology and Perioperative Medicine, Dongfang Hospital, Xiamen University, Fuzhou, 350025, China.,Pain Research Institute, Fujian Medical University, Fuzhou, 350025, China
| | - Jun-Jie Jing
- Department of Neurosurgery, Fujian Children's Hospital, College of Clinical Medicine for Obstetrics & Gynecology and Pediatrics, Fujian Medical University, Fuzhou, 350025, China
| | - Si-Yin Fu
- Department of Anesthesiology and Perioperative Medicine, Fuzong Clinical College/900th Hospital of the Joint Logistic Support Force, Fujian Medical University, Fuzhou, 350025, China.,Department of Anesthesiology and Perioperative Medicine, Dongfang Hospital, Xiamen University, Fuzhou, 350025, China
| | - Xiu-Zhu Su
- Department of Anesthesiology and Perioperative Medicine, Fuzong Clinical College/900th Hospital of the Joint Logistic Support Force, Fujian Medical University, Fuzhou, 350025, China.,Department of Anesthesiology and Perioperative Medicine, Dongfang Hospital, Xiamen University, Fuzhou, 350025, China
| | - Yu-Ling Zhong
- Department of Anesthesiology and Perioperative Medicine, Fuzong Clinical College/900th Hospital of the Joint Logistic Support Force, Fujian Medical University, Fuzhou, 350025, China.,Department of Anesthesiology and Perioperative Medicine, Dongfang Hospital, Xiamen University, Fuzhou, 350025, China
| | - Dong-Sheng Chen
- Department of Anesthesiology and Perioperative Medicine, Fuzong Clinical College/900th Hospital of the Joint Logistic Support Force, Fujian Medical University, Fuzhou, 350025, China. .,Department of Anesthesiology and Perioperative Medicine, Dongfang Hospital, Xiamen University, Fuzhou, 350025, China.
| | - Xiao-Zhi Wu
- Department of Anesthesiology and Perioperative Medicine, Fuzong Clinical College/900th Hospital of the Joint Logistic Support Force, Fujian Medical University, Fuzhou, 350025, China. .,Department of Anesthesiology and Perioperative Medicine, Dongfang Hospital, Xiamen University, Fuzhou, 350025, China.
| | - Yi-Qing Zou
- Department of Anesthesiology and Perioperative Medicine, Fuzong Clinical College/900th Hospital of the Joint Logistic Support Force, Fujian Medical University, Fuzhou, 350025, China. .,Department of Anesthesiology and Perioperative Medicine, Dongfang Hospital, Xiamen University, Fuzhou, 350025, China.
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Liu S, Lan XB, Tian MM, Zhu CH, Ma L, Yang JM, Du J, Zheng P, Yu JQ, Liu N. Targeting the chemokine ligand 2-chemokine receptor 2 axis provides the possibility of immunotherapy in chronic pain. Eur J Pharmacol 2023; 947:175646. [PMID: 36907261 DOI: 10.1016/j.ejphar.2023.175646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 02/26/2023] [Accepted: 03/06/2023] [Indexed: 03/13/2023]
Abstract
Chronic pain affects patients' physical and psychological health and quality of life, entailing a tremendous public health challenge. Currently, drugs for chronic pain are usually associated with a large number of side effects and poor efficacy. Chemokines in the neuroimmune interface combine with their receptors to regulate inflammation or mediate neuroinflammation in the peripheral and central nervous system. Targeting chemokines and their receptor-mediated neuroinflammation is an effective means to treat chronic pain. In recent years, growing evidence has shown that the expression of chemokine ligand 2 (CCL2) and its main chemokine receptor 2 (CCR2) is involved in its occurrence, development and maintenance of chronic pain. This paper summarises the relationship between the chemokine system, CCL2/CCR2 axis, and chronic pain, and the CCL2/CCR2 axis changes under different chronic pain conditions. Targeting chemokine CCL2 and its chemokine receptor CCR2 through siRNA, blocking antibodies, or small molecule antagonists may provide new therapeutic possibilities for managing chronic pain.
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Affiliation(s)
- Shan Liu
- Department of Pharmacology, School of Pharmacy, Ningxia Medical University, 1160 Shengli Street, Yinchuan, 750004, China.
| | - Xiao-Bing Lan
- Department of Pharmacology, School of Pharmacy, Ningxia Medical University, 1160 Shengli Street, Yinchuan, 750004, China.
| | - Miao-Miao Tian
- Department of Pharmacology, School of Pharmacy, Ningxia Medical University, 1160 Shengli Street, Yinchuan, 750004, China.
| | - Chun-Hao Zhu
- Department of Pharmacology, School of Pharmacy, Ningxia Medical University, 1160 Shengli Street, Yinchuan, 750004, China.
| | - Lin Ma
- Department of Pharmacology, School of Pharmacy, Ningxia Medical University, 1160 Shengli Street, Yinchuan, 750004, China.
| | - Jia-Mei Yang
- Department of Pharmacology, School of Pharmacy, Ningxia Medical University, 1160 Shengli Street, Yinchuan, 750004, China.
| | - Juan Du
- Department of Pharmacology, School of Pharmacy, Ningxia Medical University, 1160 Shengli Street, Yinchuan, 750004, China.
| | - Ping Zheng
- Department of Pharmacology, School of Pharmacy, Ningxia Medical University, 1160 Shengli Street, Yinchuan, 750004, China.
| | - Jian-Qiang Yu
- Department of Pharmacology, School of Pharmacy, Ningxia Medical University, 1160 Shengli Street, Yinchuan, 750004, China; Ningxia Special Traditional Medicine Modern Engineering Research Center and Collaborative Innovation Center, Ningxia Medical University, 1160 Shengli Street, Yinchuan, 750004, China.
| | - Ning Liu
- Department of Pharmacology, School of Pharmacy, Ningxia Medical University, 1160 Shengli Street, Yinchuan, 750004, China; Ningxia Special Traditional Medicine Modern Engineering Research Center and Collaborative Innovation Center, Ningxia Medical University, 1160 Shengli Street, Yinchuan, 750004, China.
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5
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Abstract
Inflammatory pain is the perception of noxious stimuli that occurs during inflammation or an immune response. Glial cells are widespread in the central and peripheral nervous systems, supporting and guiding the migration of neurons, participating in the immune response, forming the myelin sheath and blood-brain barrier, and maintaining the concentration of potassium ions outside nerve cells. Recent studies have shown that glial cells have a significant connection with the production and development of inflammatory pain. This article reviews the relationship, mechanisms, therapeutic targets between five types of glial cells and inflammatory pain, and the medicine composition that can effectively inhibit inflammatory pain. It expands the study on the mechanism of glial cells regulating pain and provides new ideas for the therapy of inflammatory pain.
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Affiliation(s)
- Hongji Wang
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang 330006, P.R. China
| | - Changshui Xu
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang 330006, P.R. China
- The Clinical Medical School, Jiangxi Medical College, Shangrao 334000, P.R. China
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6
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Chun S, Lee JH, Yoon SY, Kwon YB. The Peripheral Role of CCL2 in the Anti-Nociceptive Effect of Sigma-1 Receptor Antagonist BD1047 on Inflammatory Hyperalgesia in Rats. Int J Mol Sci 2021; 22:11730. [PMID: 34769165 PMCID: PMC8583891 DOI: 10.3390/ijms222111730] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 10/25/2021] [Accepted: 10/28/2021] [Indexed: 12/02/2022] Open
Abstract
Our recent study demonstrated that the CC-chemokine ligand 2 (CCL2) present in primary afferent fibers (PAFs) plays an important role in the microglia-dependent neuronal activation associated with zymosan-induced inflammatory pain. The present study was aimed to evaluate whether BD1047 (a prototypical sigma-1 receptor (Sig-1R) antagonist) is capable of modifying elevated levels of inflammation-evoked CCL2 as a peripheral antinociceptive mechanism. In DRG primary culture, zymosan dose-dependently increased CCL2 release from isolectin B4 (IB4)-positive DRG neurons, a process that was inhibited by co-culture with BD1047. Single treatment of BD1047 before intraplantar injection of zymosan in rats significantly reduced thermal hyperalgesia and mechanical hyperalgesia, as well as CCL2 expression in DRG neurons and microglia activation in the spinal dorsal horn. In the Complete Freund's adjuvant (CFA)-induced inflammation model, repeated administration of BD1047 dramatically attenuated thermal hyperalgesia and mechanical hyperalgesia, and significantly diminished CCL2 immunoreactivity and microglia activation. Notably, CFA-induced inflammation significantly increased Sig-1R immunoreactivity in DRG neurons, which was co-localized with CCL2 and IB4, respectively. Taken together, our results suggest that BD1047's anti-nociceptive property was substantially mediated by the inhibition of CCL2 release in unmyelinated PAFs and that this may, in turn, have attenuated the spinal microglia activation that is associated with inflammatory pain.
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Affiliation(s)
- Sungkun Chun
- Department of Physiology, Institute for Medical Science, Jeonbuk National University Medical School, Jeonju 54907, Korea;
| | - Jun-Ho Lee
- Department of Anesthesiology and Pain Medicine, Jeonbuk National University Medical School and Hospital, Jeonju 54907, Korea;
| | - Seo-Yeon Yoon
- Department of Pet Animal, Division of Health and Life Science, Daejeon Institute of Science and Technology, Daejeon 35408, Korea;
| | - Young-Bae Kwon
- Department of Pharmacology, Institute for Medical Science, Jeonbuk National University Medical School, Jeonju 54907, Korea
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7
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Boakye PA, Tang SJ, Smith PA. Mediators of Neuropathic Pain; Focus on Spinal Microglia, CSF-1, BDNF, CCL21, TNF-α, Wnt Ligands, and Interleukin 1β. FRONTIERS IN PAIN RESEARCH 2021; 2:698157. [PMID: 35295524 PMCID: PMC8915739 DOI: 10.3389/fpain.2021.698157] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 07/14/2021] [Indexed: 01/04/2023] Open
Abstract
Intractable neuropathic pain is a frequent consequence of nerve injury or disease. When peripheral nerves are injured, damaged axons undergo Wallerian degeneration. Schwann cells, mast cells, fibroblasts, keratinocytes and epithelial cells are activated leading to the generation of an "inflammatory soup" containing cytokines, chemokines and growth factors. These primary mediators sensitize sensory nerve endings, attract macrophages, neutrophils and lymphocytes, alter gene expression, promote post-translational modification of proteins, and alter ion channel function in primary afferent neurons. This leads to increased excitability and spontaneous activity and the generation of secondary mediators including colony stimulating factor 1 (CSF-1), chemokine C-C motif ligand 21 (CCL-21), Wnt3a, and Wnt5a. Release of these mediators from primary afferent neurons alters the properties of spinal microglial cells causing them to release tertiary mediators, in many situations via ATP-dependent mechanisms. Tertiary mediators such as BDNF, tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), and other Wnt ligands facilitate the generation and transmission of nociceptive information by increasing excitatory glutamatergic transmission and attenuating inhibitory GABA and glycinergic transmission in the spinal dorsal horn. This review focusses on activation of microglia by secondary mediators, release of tertiary mediators from microglia and a description of their actions in the spinal dorsal horn. Attention is drawn to the substantial differences in the precise roles of various mediators in males compared to females. At least 25 different mediators have been identified but the similarity of their actions at sensory nerve endings, in the dorsal root ganglia and in the spinal cord means there is considerable redundancy in the available mechanisms. Despite this, behavioral studies show that interruption of the actions of any single mediator can relieve signs of pain in experimental animals. We draw attention this paradox. It is difficult to explain how inactivation of one mediator can relieve pain when so many parallel pathways are available.
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Affiliation(s)
- Paul A. Boakye
- Department of Anesthesiology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, United States
| | - Shao-Jun Tang
- Department of Anesthesiology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, United States
| | - Peter A. Smith
- Neuroscience and Mental Health Institute and Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
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8
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Abstract
In rheumatology, chronic pain most often sets in after a musculoskeletal injury. Its persistence is not always due to the progression of the initial injury, but in some cases to the onset of central sensitization. Much scientific data suggests that this central sensitization is caused by multiple complex interactions between the nervous system and immune system. Afferent nerve fibers carrying pain information are responsible for peripheral sensitization partly linked to inflammation molecules. These afferent fibers release neurotransmitters in the dorsal root ganglion and dorsal horn of the spinal cord, capable of activating microglia, which are the local immune cells. The activated microglia will produce pro-inflammatory cytokines, chemokines and neuropeptides capable of interacting with the second-order neuron, but also segmental and descending inhibitory neurons. This is referred to as neuroinflammation, which will amplify the hypersensitivity of second-order neurons, otherwise called central sensitization. This neuroinflammation will be able to reach the higher brain structures, which are involved in pain modulation and the emotional and cognitive aspects of pain. The aim of this update is to describe the pathophysiology of chronic pain, incorporating the latest scientific data on neuroplasticity and neuroinflammation.
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Affiliation(s)
- Pascale Vergne-Salle
- Service de rhumatologie, CHU de Dupuytren 2, 16, rue Bernard-Descottes, 87042 Limoges, France.
| | - Philippe Bertin
- Service de rhumatologie, CHU de Dupuytren 2, 16, rue Bernard-Descottes, 87042 Limoges, France
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Huhtakangas JA, Huovinen J, Laaksonen S, Voipio HM, Vuolteenaho O, Finnilä MAJ, Thevenot J, Lehenkari PP. A single intra-articular dose of vitamin D analog calcipotriol alleviates synovitis without adverse effects in rats. PLoS One 2021; 16:e0250352. [PMID: 33878143 PMCID: PMC8057567 DOI: 10.1371/journal.pone.0250352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 04/05/2021] [Indexed: 11/19/2022] Open
Abstract
1,25-dihydroxyvitamin-D3 and its derivatives have shown anti-arthritic and chondroprotective effects in experimental animal models with prophylactic dosing. The purpose of this preliminary study was to test the efficacy and safety of calcipotriol, vitamin D analog, as a treatment for a fully-developed knee arthritis in Zymosan-induced arthritis (ZIA) model. Forty 5-month-old male Sprague-Dawley rats were randomized into three arthritis groups and a non-arthritic control group with no injections (10 rats/group). A day after Zymosan (0.1 mg) had been administrated into the right knee joints, the same knees were injected with calcipotriol (0.1 mg/kg), dexamethasone (0.1 mg/kg) or vehicle in a 100 μl volume. The left control knees were injected with saline (PBS) on two consecutive days. All injections, blood sampling and measurements were performed under general anesthesia on days 0, 1, 3 and 8. Internal organs and knees were harvested on day 8 and the histology of the whole knees was assessed blinded. Joints treated with calcipotriol showed a milder histological synovitis than those treated with vehicle (p = 0.041), but there was no statistically significant difference between the dexamethasone and vehicle groups. The clinical severity of arthritis did not differ between the arthritis groups measured by body temperature, swelling of the knee, thermal imaging, clinical scoring or cytokine levels on days 1, 3 and 8. Weight loss was bigger in rats treated with dexamethasone, propably due to loss of appetite,compared to other arthritis groups on days 2-3 (p<0.05). Study drugs did not influence serum calcium ion and glucose levels. Taken together, this preliminary study shows that a single intra-articular injection of calcipotriol reduces histological grade of synovitis a week after the local injection, but dexamethasone did not differ from the vehicle. Calcipotriol may have an early disease-modifying effect in the rat ZIA model without obvious side effects.
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Affiliation(s)
- Johanna A. Huhtakangas
- Cancer Research and Translational Medicine Research Unit, Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland
- Department of Medicine, Rheumatology Unit, Oulu University Hospital, Medical Research Center Oulu, Oulu, Finland
- * E-mail:
| | - Jere Huovinen
- Cancer Research and Translational Medicine Research Unit, Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland
| | - Sakari Laaksonen
- Oulu Laboratory Animal Center, Department of Experimental Surgery, Oulu University Hospital and University of Oulu, Oulu, Finland
| | - Hanna-Marja Voipio
- Oulu Laboratory Animal Center, Department of Experimental Surgery, Oulu University Hospital and University of Oulu, Oulu, Finland
| | - Olli Vuolteenaho
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Mikko A. J. Finnilä
- Faculty of Medicine, Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland
| | - Jérôme Thevenot
- Faculty of Medicine, Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland
| | - Petri P. Lehenkari
- Cancer Research and Translational Medicine Research Unit, Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland
- Division of Operative Care, Oulu University Hospital and University of Oulu, Oulu, Finland
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10
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Singh G, Segura BJ, Georgieff MK, Gisslen T. Fetal inflammation induces acute immune tolerance in the neonatal rat hippocampus. J Neuroinflammation 2021; 18:69. [PMID: 33706765 PMCID: PMC7953777 DOI: 10.1186/s12974-021-02119-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 02/24/2021] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Infants born preterm due to chorioamnionitis are frequently affected by a fetal inflammatory response syndrome (FIRS) and then by subsequent postnatal infections. FIRS and postnatal systemic inflammatory events independently contribute to poor neurocognitive outcomes of preterm infants. Developmental integrity of the hippocampus is crucial for intact neurocognitive outcomes in preterms and hippocampally dependent behaviors are particularly vulnerable to preterm systemic inflammation. How FIRS modulates the hippocampal immune response to acute postnatal inflammatory events is not well understood. METHODS Prenatal LPS exposed (FIRS) and control neonatal rats received i.p. LPS or saline at postnatal day (P) 5. On P7, immune response was evaluated in the hippocampus of four treatment groups by measuring gene expression of inflammatory mediators and cytosolic and nuclear NFκB pathway proteins. Microglial activation was determined by CD11b+ and Iba1+ immunohistochemistry (IHC) and inflammatory gene expression of isolated microglia. Astrocyte reactivity was measured using Gfap+ IHC. RESULTS Postnatal LPS resulted in a robust hippocampal inflammatory response. In contrast, FIRS induced by prenatal LPS attenuated the response to postnatal LPS exposure, evidenced by decreased gene expression of inflammatory mediators, decreased nuclear NFκB p65 protein, and fewer activated CD11b+ and Iba1+ microglia. Isolated microglia demonstrated inflammatory gene upregulation to postnatal LPS without evidence of immune tolerance by prenatal LPS. CONCLUSION Prenatal LPS exposure induced immune tolerance to subsequent postnatal LPS exposure in the hippocampus. Microglia demonstrate a robust inflammatory response to postnatal LPS, but only a partial immune tolerance response.
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Affiliation(s)
- Garima Singh
- Division of Neonatology, Department of Pediatrics, University of Minnesota, East Building MB630, 2450 Riverside Avenue, Minneapolis, MN, 55454, USA
| | - Bradley J Segura
- Division of Pediatric Surgery, Department of Surgery, University of Minnesota, East Building MB630, 2450 Riverside Avenue, Minneapolis, MN, 55454, USA
| | - Michael K Georgieff
- Division of Neonatology, Department of Pediatrics, University of Minnesota, East Building MB630, 2450 Riverside Avenue, Minneapolis, MN, 55454, USA
| | - Tate Gisslen
- Division of Neonatology, Department of Pediatrics, University of Minnesota, East Building MB630, 2450 Riverside Avenue, Minneapolis, MN, 55454, USA.
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11
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Zhang L, Xie W, Zhang J, Shanahan H, Tonello R, Lee SH, Strong JA, Berta T, Zhang JM. Key role of CCR2-expressing macrophages in a mouse model of low back pain and radiculopathy. Brain Behav Immun 2021; 91:556-567. [PMID: 33197543 PMCID: PMC7758110 DOI: 10.1016/j.bbi.2020.11.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 10/12/2020] [Accepted: 11/11/2020] [Indexed: 12/12/2022] Open
Abstract
Chronic low back pain is a common condition, with high societal costs and often ineffectual treatments. Communication between macrophages/monocytes (MØ) and sensory neurons has been implicated in various preclinical pain models. However, few studies have examined specific MØ subsets, although distinct subtypes may play opposing roles. This study used a model of low back pain/radiculopathy involving direct local inflammation of the dorsal root ganglia (DRG). Reporter mice were employed that had distinct fluorescent labels for two key MØ subsets: CCR2-expressing (infiltrating pro-inflammatory) MØ, and CX3CR1-expressing (resident) macrophages. We observed that local DRG inflammation induced pain behaviors in mice, including guarding behavior and mechanical hypersensitivity, similar to the previously described rat model. The increase in MØ in the inflamed DRG was dominated by increases in CCR2+ MØ, which persisted for at least 14 days. The primary endogenous ligand for CCR2, CCL2, was upregulated in inflamed DRG. Three different experimental manipulations that reduced the CCR2+ MØ influx also reduced pain behaviors: global CCR2 knockout; systemic injection of INCB3344 (specific CCR2 blocker); and intravenous injection of liposomal clodronate. The latter two treatments when applied around the time of DRG inflammation reduced CCR2+ but not CX3CR1+ MØ in the DRG. Together these experiments suggest a key role for the CCR2/CCL2 system in establishing the pain state in this model of inflammatory low back pain and radiculopathy. Intravenous clodronate given after pain was established had the opposite effect on pain behaviors, suggesting the role of macrophages or their susceptibility to clodronate may change with time.
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Affiliation(s)
- Li Zhang
- Pain Research Center, Department of Anesthesiology, University of Cincinnati College of Medicine, Cincinnati, OH 45040, USA; Department of Anesthesiology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China
| | - Wenrui Xie
- Pain Research Center, Department of Anesthesiology, University of Cincinnati College of Medicine, Cincinnati, OH 45040, USA
| | - Jingdong Zhang
- Pain Research Center, Department of Anesthesiology, University of Cincinnati College of Medicine, Cincinnati, OH 45040, USA
| | - Hailey Shanahan
- Pain Research Center, Department of Anesthesiology, University of Cincinnati College of Medicine, Cincinnati, OH 45040, USA
| | - Raquel Tonello
- Pain Research Center, Department of Anesthesiology, University of Cincinnati College of Medicine, Cincinnati, OH 45040, USA
| | - Sang Hoon Lee
- Pain Research Center, Department of Anesthesiology, University of Cincinnati College of Medicine, Cincinnati, OH 45040, USA
| | - Judith A Strong
- Pain Research Center, Department of Anesthesiology, University of Cincinnati College of Medicine, Cincinnati, OH 45040, USA
| | - Temugin Berta
- Pain Research Center, Department of Anesthesiology, University of Cincinnati College of Medicine, Cincinnati, OH 45040, USA
| | - Jun-Ming Zhang
- Pain Research Center, Department of Anesthesiology, University of Cincinnati College of Medicine, Cincinnati, OH 45040, USA.
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Ma SB, Xian H, Wu WB, Ma SY, Liu YK, Liang YT, Guo H, Kang JJ, Liu YY, Zhang H, Wu SX, Luo C, Xie RG. CCL2 facilitates spinal synaptic transmission and pain via interaction with presynaptic CCR2 in spinal nociceptor terminals. Mol Brain 2020; 13:161. [PMID: 33228784 PMCID: PMC7685578 DOI: 10.1186/s13041-020-00701-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 11/17/2020] [Indexed: 12/19/2022] Open
Abstract
Previous studies have shown that CCL2 may cause chronic pain, but the exact mechanism of central sensitization is unclear. In this article, we further explore the presynaptic role of CCL2. Behavioral experiments show that intervertebral foramen injection CCR2 antagonists into dorsal root ganglion (DRG) can inhibit the inflammatory pain caused by CCL2 in spinal cord. We raised the question of the role of presynaptic CCR2 in the spinal dorsal horn. Subsequent electron microscopy experiments showed that CCR2 was expressed in the presynaptic CGRP terminal in the spinal dorsal horn. CCL2 can enhance presynaptic calcium signal. Whole-cell patch-clamp recordings showed that CCL2 can enhance NMDAR-eEPSCs through presynaptic effects, and further application of glutamate sensor method proved that CCL2 can act on presynaptic CCR2 to increase the release of presynaptic glutamate. In conclusion, we suggest that CCL2 can directly act on the CCR2 on presynaptic terminals of sensory neurons in the spinal dorsal horn, leading to an increase in the release of presynaptic glutamate and participate in the formation of central sensitization.
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Affiliation(s)
- Sui-Bin Ma
- Department of Neurobiology, Fourth Military Medical University, Xi'an, 710032, China
| | - Hang Xian
- Department of Neurobiology, Fourth Military Medical University, Xi'an, 710032, China.,Department of Orthopedics, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China
| | - Wen-Bin Wu
- The Fourth Regiment, School of Basic Medicine, Fourth Military Medical University, Xi'an, 710032, China
| | - Shuo-Yao Ma
- The Sixth Regiment, School of Basic Medicine, Fourth Military Medical University, Xi'an, 710032, China
| | - Yu-Ke Liu
- The Second Regiment, School of Basic Medicine, Fourth Military Medical University, Xi'an, 710032, China
| | - Yu-Tong Liang
- The Second Regiment, School of Basic Medicine, Fourth Military Medical University, Xi'an, 710032, China
| | - Huan Guo
- Department of Neurobiology, Fourth Military Medical University, Xi'an, 710032, China.,Pain and Related Diseases Research Laboratory, Medical College of Shantou University, Shantou, 515041, China
| | - Jun-Jun Kang
- Department of Neurobiology, Fourth Military Medical University, Xi'an, 710032, China
| | - Ying-Ying Liu
- Department of Neurobiology, Fourth Military Medical University, Xi'an, 710032, China
| | - Hui Zhang
- Department of Neurobiology, Fourth Military Medical University, Xi'an, 710032, China.,Department of Health Statistics, Fourth Military Medical University, Xi'an, 710032, China
| | - Sheng-Xi Wu
- Department of Neurobiology, Fourth Military Medical University, Xi'an, 710032, China
| | - Ceng Luo
- Department of Neurobiology, Fourth Military Medical University, Xi'an, 710032, China.
| | - Rou-Gang Xie
- Department of Neurobiology, Fourth Military Medical University, Xi'an, 710032, China.
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Neuronal/astrocytic expression of chemokine (C-C motif) ligand 2 is associated with monocyte/macrophage recruitment in male chronic pelvic pain. Pain 2020; 161:2581-2591. [PMID: 32541388 DOI: 10.1097/j.pain.0000000000001954] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Chronic pelvic pain syndrome is a multisymptom syndrome with unknown etiology. The experimental autoimmune prostatitis (EAP) mouse model of chronic pelvic pain syndrome is associated with immune cell infiltration into the prostate, expression of C-C chemokine ligand 2 (CCL2), and neuroinflammation in the spinal cord. Here, we studied CCL2 expression in tissues along the nociceptive pathway and its association with neuroimmune cells during pain development. Examination of prostate tissues at days 14 and 28 after EAP induction revealed CCL2 expression was increased in epithelial cells and was associated with increased numbers of macrophages lying in close apposition to PGP9.5-positive afferent neuronal fibers. C-C Chemokine ligand 2 immunoreactivity was elevated to a similar degree in the dorsal root ganglia at day 14 and day 28. D14 of EAP was associated with elevated IBA1 cells in the dorsal root ganglia that were not evident at D28. Adoptive transfer of green fluorescent protein+ leukocytes into EAP mice demonstrated monocytes are capable of infiltrating the spinal cord from peripheral blood with what seemed to be a proinflammatory phenotype. In the lower dorsal spinal cord, CCL2 expression localized to NeuN expressing neurons and GFAP-expressing astrocytes. Myeloid derived cell infiltration into the spinal cord in EAP was observed in the L6-S2 dorsal horn. Myeloid-derived CD45 IBA1+ cells were localized with IBA1+ TMEM199+ microglia in the dorsal horn of the spinal cord in EAP, with intimate association of the 2 cell types suggesting cell-cell interactions. Finally, intrathecal administration of liposomal clodronate ameliorated pelvic pain symptoms, suggesting a mechanistic role for macrophages and microglia in chronic pelvic pain.
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Suppression of Superficial Microglial Activation by Spinal Cord Stimulation Attenuates Neuropathic Pain Following Sciatic Nerve Injury in Rats. Int J Mol Sci 2020; 21:ijms21072390. [PMID: 32235682 PMCID: PMC7177766 DOI: 10.3390/ijms21072390] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 03/27/2020] [Accepted: 03/27/2020] [Indexed: 12/29/2022] Open
Abstract
We evaluated the mechanisms underlying the spinal cord stimulation (SCS)-induced analgesic effect on neuropathic pain following spared nerve injury (SNI). On day 3 after SNI, SCS was performed for 6 h by using electrodes paraspinally placed on the L4-S1 spinal cord. The effects of SCS and intraperitoneal minocycline administration on plantar mechanical sensitivity, microglial activation, and neuronal excitability in the L4 dorsal horn were assessed on day 3 after SNI. The somatosensory cortical responses to electrical stimulation of the hind paw on day 3 following SNI were examined by using in vivo optical imaging with a voltage-sensitive dye. On day 3 after SNI, plantar mechanical hypersensitivity and enhanced microglial activation were suppressed by minocycline or SCS, and L4 dorsal horn nociceptive neuronal hyperexcitability was suppressed by SCS. In vivo optical imaging also revealed that electrical stimulation of the hind paw-activated areas in the somatosensory cortex was decreased by SCS. The present findings suggest that SCS could suppress plantar SNI-induced neuropathic pain via inhibition of microglial activation in the L4 dorsal horn, which is involved in spinal neuronal hyperexcitability. SCS is likely to be a potential alternative and complementary medicine therapy to alleviate neuropathic pain following nerve injury.
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