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Casadei M, Miguel B, Rubione J, Fiore E, Mengelle D, Guerri-Guttenberg RA, Montaner A, Villar MJ, Constandil-Córdova L, Romero-Sandoval AE, Brumovsky PR. Mesenchymal Stem Cell Engagement Modulates Neuroma Microenviroment in Rats and Humans and Prevents Postamputation Pain. THE JOURNAL OF PAIN 2024:104508. [PMID: 38484854 DOI: 10.1016/j.jpain.2024.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 03/05/2024] [Accepted: 03/06/2024] [Indexed: 04/11/2024]
Abstract
Postamputation pain is currently managed unsatisfactorily with neuron-targeted pharmacological and interventional therapies. Non-neuronal pain mechanisms have emerged as crucial factors in the development and persistence of postamputation pain. Consequently, these mechanisms offer exciting prospects as innovative therapeutic targets. We examined the hypothesis that engaging mesenchymal stem cells (MSCs) would foster local neuroimmune interactions, leading to a potential reduction in postamputation pain. We utilized an ex vivo neuroma model from a phantom limb pain patient to uncover that the oligodeoxynucleotide IMT504 engaged human primary MSCs to promote an anti-inflammatory microenvironment. Reverse translation experiments recapitulated these effects. Thus, in an in vivo rat model, IMT504 exhibited strong efficacy in preventing autotomy (self-mutilation) behaviors. This effect was linked to a substantial accumulation of MSCs in the neuroma and associated dorsal root ganglia and the establishment of an anti-inflammatory phenotype in these compartments. Centrally, this intervention reduced glial reactivity in the dorsal horn spinal cord, demonstrating diminished nociceptive activity. Accordingly, the exogenous systemic administration of MSCs phenocopied the behavioral effects of IMT504. Our findings underscore the mechanistic relevance of MSCs and the translational therapeutic potential of IMT504 to engage non-neuronal cells for the prevention of postamputation pain. PERSPECTIVE: The present study suggests that IMT504-dependent recruitment of endogenous MSCs within severely injured nerves may prevent post-amputation pain by modifying the inflammatory scenario at relevant sites in the pain pathway. Reinforcing data in rat and human tissues supports the potential therapeutic value of IMT504 in patients suffering postamputation pain.
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Affiliation(s)
- Mailín Casadei
- Laboratorio de Mecanismos e Innovación Terapéutico en Dolor, Instituto de Investigaciones en Medicina Traslacional, CONICET-Universidad Austral, Buenos Aires, Argentina
| | - Bernardo Miguel
- Laboratorio de Mecanismos e Innovación Terapéutico en Dolor, Instituto de Investigaciones en Medicina Traslacional, CONICET-Universidad Austral, Buenos Aires, Argentina
| | - Julia Rubione
- Laboratorio de Mecanismos e Innovación Terapéutico en Dolor, Instituto de Investigaciones en Medicina Traslacional, CONICET-Universidad Austral, Buenos Aires, Argentina
| | - Esteban Fiore
- Laboratorio de Mecanismos e Innovación Terapéutico en Dolor, Instituto de Investigaciones en Medicina Traslacional, CONICET-Universidad Austral, Buenos Aires, Argentina
| | - Diego Mengelle
- Hospital Universitario Austral, Universidad Austral, Buenos Aires, Argentina
| | | | - Alejandro Montaner
- Laboratorio de Fármacolos Inmunomoduladores, Instituto de Ciencia y Tecnología "César Milstein", CONICET-Fundación Pablo Cassará, Buenos Aires, Argentina
| | - Marcelo J Villar
- Laboratorio de Mecanismos e Innovación Terapéutico en Dolor, Instituto de Investigaciones en Medicina Traslacional, CONICET-Universidad Austral, Buenos Aires, Argentina
| | | | - Alfonso E Romero-Sandoval
- Pain Mechanisms Laboratory, Wake Forest University School of Medicine, Winston Salem, North Carolina
| | - Pablo R Brumovsky
- Laboratorio de Mecanismos e Innovación Terapéutico en Dolor, Instituto de Investigaciones en Medicina Traslacional, CONICET-Universidad Austral, Buenos Aires, Argentina
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Mazzone GL, Coronel MF, Mladinic M, Sámano C. An update to pain management after spinal cord injury: from pharmacology to circRNAs. Rev Neurosci 2023; 34:599-611. [PMID: 36351309 DOI: 10.1515/revneuro-2022-0089] [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: 07/22/2022] [Accepted: 10/19/2022] [Indexed: 08/04/2023]
Abstract
Neuropathic pain (NP) following a spinal cord injury (SCI) is often hard to control and therapies should be focused on the physical, psychological, behavioral, social, and environmental factors that may contribute to chronic sensory symptoms. Novel therapeutic treatments for NP management should be based on the combination of pharmacological and nonpharmacological options. Some of them are addressed in this review with a focus on mechanisms and novel treatments. Several reports demonstrated an aberrant expression of non-coding RNAs (ncRNAs) that may represent key regulatory factors with a crucial role in the pathophysiology of NP and as potential diagnostic biomarkers. This review analyses the latest evidence for cellular and molecular mechanisms associated with the role of circular RNAs (circRNAs) in the management of pain after SCI. Advantages in the use of circRNA are their stability (up to 48 h), and specificity as sponges of different miRNAs related to SCI and nerve injury. The present review discusses novel data about deregulated circRNAs (up or downregulated) that sponge miRNAs, and promote cellular and molecular interactions with mRNAs and proteins. This data support the concept that circRNAs could be considered as novel potential therapeutic targets for NP management especially after spinal cord injuries.
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Affiliation(s)
- Graciela L Mazzone
- Instituto de Investigaciones en Medicina Traslacional (IIMT), CONICET-Universidad Austral, Av. Pte. Perón 1500, B1629AHJ, Pilar, Buenos Aires, Argentina
| | - María F Coronel
- Instituto de Investigaciones en Medicina Traslacional (IIMT), CONICET-Universidad Austral, Av. Pte. Perón 1500, B1629AHJ, Pilar, Buenos Aires, Argentina
| | - Miranda Mladinic
- Laboratory for Molecular Neurobiology, Department of Biotechnology, University of Rijeka, 51000 Rijeka, Croatia
| | - Cynthia Sámano
- Departamento de Ciencias Naturales, Universidad Autónoma Metropolitana, Unidad Cuajimalpa. Avenida Vasco de Quiroga 4871, Col. Santa Fe Cuajimalpa. Alcaldía Cuajimalpa de Morelos, C.P. 05348, Ciudad de México, México
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3
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Rubione J, Sbrascini SM, Miguel B, Leiguarda C, Coronel MF, McCarthy CJ, Montaner A, Villar MJ, Brumovsky PR. Modulation of the Inflammatory Response by Pre-emptive Administration of IMT504 Reduces Postoperative Pain in Rats and has Opioid-Sparing Effects. THE JOURNAL OF PAIN 2023; 24:991-1008. [PMID: 36706889 DOI: 10.1016/j.jpain.2023.01.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 01/12/2023] [Accepted: 01/16/2023] [Indexed: 01/26/2023]
Abstract
Despite the available knowledge on underlying mechanisms and the development of several therapeutic strategies, optimal management of postoperative pain remains challenging. This preclinical study hypothesizes that, by promoting an anti-inflammatory scenario, pre-emptive administration of IMT504, a noncoding, non-CpG oligodeoxynucleotide with immune modulating properties, will reduce postincisional pain, also facilitating therapeutic opioid-sparing. Male adult Sprague-Dawley rats with unilateral hindpaw skin-muscle incision received pre-emptive (48 and 24 hours prior to surgery) or postoperative (6 hours after surgery) subcutaneous vehicle (saline) or IMT504. Various groups of rats were prepared for pain-like behavior analyses, including subgroups receiving morphine or naloxone, as well as for flow-cytometry or quantitative RT-PCR analyses of the spleen and hindpaws (for analysis of inflammatory phenotype). Compared to vehicle-treated rats, pre-emptive IMT504 significantly reduced mechanical allodynia by 6 hours after surgery, and accelerated recovery of basal responses from 72 hours after surgery and onwards. Cold allodynia was also reduced by IMT504. Postoperative administration of IMT504 resulted in similar positive effects on pain-like behavior. In IMT504-treated rats, 3 mg/kg morphine resulted in comparable blockade of mechanical allodynia as observed in vehicle-treated rats receiving 10 mg/kg morphine. IMT504 significantly increased hindpaw infiltration of mesenchymal stem cells, CD4+T and B cells, and caused upregulated or downregulated transcript expressions of interleukin-10 and interleukin-1β, respectively. Also, IMT504 treatment targeted the spleen, with upregulated or downregulated transcript expressions, 6 hours after incision, of interleukin-10 and interleukin-1β, respectively. Altogether, pre-emptive or postoperative IMT504 provides protection against postincisional pain, through participation of significant immunomodulatory actions, and exhibiting opioid-sparing effects. PERSPECTIVE: This preclinical study introduces the noncoding non-CpG oligodeoxynucleotide IMT504 as a novel modulator of postoperative pain and underlying inflammatory events. The opioid-sparing effects observed for IMT504 appear as a key feature that could contribute, in the future, to reducing opioid-related adverse events in patients undergoing surgical intervention.
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Affiliation(s)
- Julia Rubione
- Instituto de Investigaciones en Medicina Traslacional (IIMT) CONICET, Universidad Austral, Pilar, Buenos Aires, Argentina
| | - Sandra M Sbrascini
- Instituto de Investigaciones en Medicina Traslacional (IIMT) CONICET, Universidad Austral, Pilar, Buenos Aires, Argentina; Hospital Universitario Austral, Universidad Austral, Pilar, Buenos Aires, Argentina
| | - Bernardo Miguel
- Instituto de Investigaciones en Medicina Traslacional (IIMT) CONICET, Universidad Austral, Pilar, Buenos Aires, Argentina
| | - Candelaria Leiguarda
- Instituto de Investigaciones en Medicina Traslacional (IIMT) CONICET, Universidad Austral, Pilar, Buenos Aires, Argentina
| | - María F Coronel
- Instituto de Investigaciones en Medicina Traslacional (IIMT) CONICET, Universidad Austral, Pilar, Buenos Aires, Argentina
| | - Carly J McCarthy
- Instituto de Investigaciones en Medicina Traslacional (IIMT) CONICET, Universidad Austral, Pilar, Buenos Aires, Argentina
| | - Alejandro Montaner
- Instituto de Ciencia y Tecnología "Dr. César Milstein", CONICET, Fundación Pablo Cassará, Pilar, Buenos Aires, Argentina
| | - Marcelo J Villar
- Instituto de Investigaciones en Medicina Traslacional (IIMT) CONICET, Universidad Austral, Pilar, Buenos Aires, Argentina
| | - Pablo R Brumovsky
- Instituto de Investigaciones en Medicina Traslacional (IIMT) CONICET, Universidad Austral, Pilar, Buenos Aires, Argentina.
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Belo TCA, Santos GX, da Silva BEG, Rocha BLG, Abdala DW, Freire LAM, Rocha FS, Galdino G. IL-10/β-Endorphin-Mediated Neuroimmune Modulation on Microglia during Antinociception. Brain Sci 2023; 13:brainsci13050789. [PMID: 37239261 DOI: 10.3390/brainsci13050789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 05/09/2023] [Accepted: 05/11/2023] [Indexed: 05/28/2023] Open
Abstract
Microglia are glial cells centrally related to pathophysiology and neuroimmunological regulation of pain through microglia-neuron crosstalk mechanisms. In contrast, anti-inflammatory mechanisms guided by immunological effectors such as IL-10 trigger the secretion of analgesic substances, culminating in the differential expression of genes encoding endogenous opioid peptides, especially β-endorphin. Thus, when β-endorphin binds to the µ-opioid receptor, it generates neuronal hyperpolarization, inhibiting nociceptive stimuli. This review aimed to summarize the recent advances in understanding the mechanism by which IL-10/β-endorphin can reduce pain. For this, databases were searched for articles from their inception up until November 2022. Two independent reviewers extracted the data and assessed the methodological quality of the included studies, and seventeen studies were considered eligible for this review. Several studies have demonstrated the impact of IL-10/β-endorphin in reducing pain, where IL-10 can stimulate GLP-1R, GRP40, and α7nAChR receptors, as well as intracellular signaling pathways, such as STAT3, resulting in increased β-endorphin expression and secretion. In addition, molecules such as gabapentinoids, thalidomide, cynandione A, morroniside, lemairamin, and cinobufagin, as well as non-pharmacological treatments such as electroacupuncture, reduce pain through IL-10 mediated mechanisms, reflecting a microglia-dependent β-endorphin differential increase. This process represents a cornerstone in pain neuroimmunology knowledge, and the results obtained by different studies about the theme are presented in this review.
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Affiliation(s)
| | - Gabriela Xavier Santos
- Laboratory of Neuroimmunobiology of Pain, Federal University of Alfenas, Alfenas 37130-001, Brazil
| | | | | | - Dennis William Abdala
- Laboratory of Movement Analysis, Federal University of Alfenas, Alfenas 37130-001, Brazil
| | - Larissa Alves Moreira Freire
- Laboratory of Neuroscience, Neuroimmunomodulation and Pain Study, Federal University of Alfenas, Alfenas 37130-001, Brazil
| | - Fernanda Santos Rocha
- Laboratory of Neuroimmunobiology of Pain, Federal University of Alfenas, Alfenas 37130-001, Brazil
| | - Giovane Galdino
- Laboratory of Neuroimmunobiology of Pain, Federal University of Alfenas, Alfenas 37130-001, Brazil
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Casadei M, Fiore E, Rubione J, María Domínguez L, Florencia Coronel M, Leiguarda C, García M, Mazzolini G, Villar MJ, Montaner A, Constandil L, Romero-Sandoval A, Brumovsky PR. IMT504 blocks allodynia in rats with spared nerve injury by promoting the migration of mesenchymal stem cells and by favoring an anti-inflammatory milieu at the injured nerve. Pain 2022; 163:1114-1129. [PMID: 34711765 PMCID: PMC8920950 DOI: 10.1097/j.pain.0000000000002476] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 08/31/2021] [Indexed: 11/26/2022]
Abstract
ABSTRACT IMT504, a noncoding, non-CpG oligodeoxynucleotide, modulates pain-like behavior in rats undergoing peripheral nerve injury, through mechanisms that remain poorly characterized. Here, we chose the spared nerve injury model in rats to analyze the contribution of mesenchymal stem cells (MSCs) in the mechanisms of action of IMT504. We show that a single subcutaneous administration of IMT504 reverses mechanical and cold allodynia for at least 5 weeks posttreatment. This event correlated with long-lasting increases in the percentage of MSCs in peripheral blood and injured sciatic nerves, in a process seemingly influenced by modifications in the CXCL12-CXCR4 axis. Also, injured nerves presented with reduced tumor necrosis factor-α and interleukin-1β and increased transforming growth factor-β1 and interleukin-10 protein levels. In vitro analysis of IMT504-pretreated rat or human MSCs revealed internalized oligodeoxynucleotide and confirmed its promigratory effects. Moreover, IMT504-pretreatment induced transcript expression of Tgf-β1 and Il-10 in MSCs; the increase in Il-10 becoming more robust after exposure to injured nerves. Ex vivo exposure of injured nerves to IMT504-pretreated MSCs confirmed the proinflammatory to anti-inflammatory switch observed in vivo. Interestingly, the sole exposure of injured nerves to IMT504 also resulted in downregulated Tnf-α and Il-1β transcripts. Altogether, we reveal for the first time a direct association between the antiallodynic actions of IMT504, its promigratory and cytokine secretion modulating effects on MSCs, and further anti-inflammatory actions at injured nerves. The recapitulation of key outcomes in human MSCs supports the translational potential of IMT504 as a novel treatment for neuropathic pain with a unique mechanism of action involving the regulation of neuroimmune interactions.
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Affiliation(s)
- Mailín Casadei
- Instituto de Investigaciones en Medicina Traslacional (IIMT), CONICET-Universidad Austral, Av. Juan D. Perón 1500, Derqui, Pilar, Buenos Aires, Argentina
| | - Esteban Fiore
- Instituto de Investigaciones en Medicina Traslacional (IIMT), CONICET-Universidad Austral, Av. Juan D. Perón 1500, Derqui, Pilar, Buenos Aires, Argentina
| | - Julia Rubione
- Instituto de Investigaciones en Medicina Traslacional (IIMT), CONICET-Universidad Austral, Av. Juan D. Perón 1500, Derqui, Pilar, Buenos Aires, Argentina
| | - Luciana María Domínguez
- Instituto de Investigaciones en Medicina Traslacional (IIMT), CONICET-Universidad Austral, Av. Juan D. Perón 1500, Derqui, Pilar, Buenos Aires, Argentina
| | - María Florencia Coronel
- Instituto de Investigaciones en Medicina Traslacional (IIMT), CONICET-Universidad Austral, Av. Juan D. Perón 1500, Derqui, Pilar, Buenos Aires, Argentina
| | - Candelaria Leiguarda
- Instituto de Investigaciones en Medicina Traslacional (IIMT), CONICET-Universidad Austral, Av. Juan D. Perón 1500, Derqui, Pilar, Buenos Aires, Argentina
| | - Mariana García
- Instituto de Investigaciones en Medicina Traslacional (IIMT), CONICET-Universidad Austral, Av. Juan D. Perón 1500, Derqui, Pilar, Buenos Aires, Argentina
| | - Guillermo Mazzolini
- Instituto de Investigaciones en Medicina Traslacional (IIMT), CONICET-Universidad Austral, Av. Juan D. Perón 1500, Derqui, Pilar, Buenos Aires, Argentina
| | - Marcelo J. Villar
- Instituto de Investigaciones en Medicina Traslacional (IIMT), CONICET-Universidad Austral, Av. Juan D. Perón 1500, Derqui, Pilar, Buenos Aires, Argentina
| | - Alejandro Montaner
- Instituto de Ciencia y Tecnología “Dr. César Milstein”, CONICET, Fundación Pablo Cassará, Ciudad Autónoma de Buenos Aires, Argentina
| | - Luis Constandil
- Laboratorio de Neurobiología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile
| | - Alfonso Romero-Sandoval
- Department of Anesthesiology, Pain Mechanisms Laboratory, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
| | - Pablo R. Brumovsky
- Instituto de Investigaciones en Medicina Traslacional (IIMT), CONICET-Universidad Austral, Av. Juan D. Perón 1500, Derqui, Pilar, Buenos Aires, Argentina
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Hsu YC, Ma KH, Guo SL, Lin BF, Tsai CS, Yeh CC. The Occurrence of Pain-Induced Depression Is Different between Rat Models of Inflammatory and Neuropathic Pain. J Clin Med 2021; 10:jcm10174016. [PMID: 34501464 PMCID: PMC8432452 DOI: 10.3390/jcm10174016] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 08/18/2021] [Accepted: 09/02/2021] [Indexed: 12/15/2022] Open
Abstract
Various pain conditions may be associated with depressed mood. However, the effect of inflammatory or neuropathic pain on depression-like behavior and its associated time frame has not been well established in rat models. This frontward study investigated the differences in pain behavior, depression-like behavior, and serotonin transporter (SERT) distribution in the brain between rats subjected to spared nerve injury (SNI)-induced neuropathic pain or complete Freund’s adjuvant (CFA)-induced inflammatory pain. A dynamic plantar aesthesiometer and an acetone spray test were used to evaluate mechanical and cold allodynia responses, and depression-like behavior was examined using a forced swimming test and sucrose preference test. We also investigated SERT expression by using positron emission tomography. We found that the inflammation-induced pain was less severe than neuropathic pain from days 3 to 28 after induced pain; however, the CFA-injected rats exhibited more noticeable depression-like behavior and had significantly reduced SERT expression in the brain regions (thalamus and striatum) at an early stage (on days 14, 21, and 28 in two groups of CFA-injected rats versus day 28 in SNI rats). We speculated that not only the pain response after initial injury but also the subsequent neuroinflammation may have been the crucial factors influencing depression-like behavior in rats.
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Affiliation(s)
- Yung-Chi Hsu
- Department of Anesthesiology, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan; (Y.-C.H.); (S.-L.G.); (B.-F.L.)
- Integrated Pain Management Center, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan
| | - Kuo-Hsing Ma
- Department of Biology and Anatomy, National Defense Medical Center, Taipei 114, Taiwan;
| | - Shu-Lin Guo
- Department of Anesthesiology, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan; (Y.-C.H.); (S.-L.G.); (B.-F.L.)
- Department of Anesthesiology, Cathay General Hospital, Taipei 106, Taiwan
- School of Medicine, Fu Jen Catholic University, New Taipei City 242, Taiwan
| | - Bo-Feng Lin
- Department of Anesthesiology, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan; (Y.-C.H.); (S.-L.G.); (B.-F.L.)
- Integrated Pain Management Center, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan
| | - Chien-Sung Tsai
- Division of Cardiovascular Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan;
- Department and Graduate Institute of Pharmacology, National Defense Medical Center, Taipei 114, Taiwan
| | - Chun-Chang Yeh
- Department of Anesthesiology, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan; (Y.-C.H.); (S.-L.G.); (B.-F.L.)
- Integrated Pain Management Center, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan
- Correspondence: ; Tel.: +886-2-8792-3311 (ext. 17051); Fax: +886-2-8792-7127
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Leiguarda C, Villarreal A, Potilinski C, Pelissier T, Coronel MF, Bayo J, Ramos AJ, Montaner A, Villar MJ, Constandil L, Brumovsky PR. Intrathecal Administration of an Anti-nociceptive Non-CpG Oligodeoxynucleotide Reduces Glial Activation and Central Sensitization. J Neuroimmune Pharmacol 2021; 16:818-834. [PMID: 33502706 DOI: 10.1007/s11481-021-09983-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 01/12/2021] [Indexed: 01/18/2023]
Abstract
Inflammatory pain associates with spinal glial activation and central sensitization. Systemic administration of IMT504, a non-CpG oligodeoxynucleotide originally designed as an immunomodulator, exerts remarkable anti-allodynic effects in rats with complete Freund´s adjuvant (CFA)-induced hindpaw inflammation. However, the anti-nociceptive mechanisms of IMT504 remain unknown. Here we evaluated whether IMT504 blocks inflammatory pain-like behavior by modulation of spinal glia and central sensitization. The study was performed in Sprague Dawley rats with intraplantar CFA, and a single lumbosacral intrathecal (i.t.) administration of IMT504 or vehicle was chosen to address if changes in glial activation and spinal sensitization relate to the pain-like behavior reducing effects of the ODN. Naïve rats were also included. Von Frey and Randall-Selitto tests, respectively, exposed significant reductions in allodynia and mechanical hypersensitivity, lasting at least 24 h after i.t. IMT504. Analysis of electromyographic responses to electrical stimulation of C fibers showed progressive reductions in wind-up responses. Accordingly, IMT504 significantly downregulated spinal glial activation, as shown by reductions in the protein expression of glial fibrillary acidic protein, CD11b/c, Toll-like receptor 4 (TLR4) and the phosphorylated p65 subunit of NFκB, evaluated by immunohistochemistry and western blot. In vitro experiments using early post-natal cortical glial cultures provided further support to in vivo data and demonstrated IMT504 internalization into microglia and astrocytes. Altogether, our study provides new evidence on the central mechanisms of anti-nociception by IMT504 upon intrathecal application, and further supports its value as a novel anti-inflammatory ODN with actions upon glial cells and the TLR4/NFκB pathway. Intrathecal administration of the non-CpG ODN IMT504 fully blocks CFA-induced mechanical allodynia and hypersensitivity, in association with reduced spinal sensitization. Administration of the ODN also results in downregulated gliosis and reduced TLR4-NF-κB pathway activation. IMT504 uptake into astrocytes and microglia support the concept of direct modulation of CFA-induced glial activation.
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Affiliation(s)
- C Leiguarda
- Instituto de Investigaciones en Medicina Traslacional (IIMT), Universidad Austral-CONICET, Av. Juan D. Perón 1500, Pilar, Buenos Aires, B1629AHJ, Argentina
| | - A Villarreal
- Laboratorio de Neuropatología Molecular, Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis" UBA-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, 1121, Argentina
| | - C Potilinski
- Instituto de Investigaciones en Medicina Traslacional (IIMT), Universidad Austral-CONICET, Av. Juan D. Perón 1500, Pilar, Buenos Aires, B1629AHJ, Argentina
| | - T Pelissier
- Laboratorio de Neurobiología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, 8320000, Chile
| | - M F Coronel
- Instituto de Investigaciones en Medicina Traslacional (IIMT), Universidad Austral-CONICET, Av. Juan D. Perón 1500, Pilar, Buenos Aires, B1629AHJ, Argentina
| | - J Bayo
- Instituto de Investigaciones en Medicina Traslacional (IIMT), Universidad Austral-CONICET, Av. Juan D. Perón 1500, Pilar, Buenos Aires, B1629AHJ, Argentina
| | - A J Ramos
- Laboratorio de Neuropatología Molecular, Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis" UBA-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, 1121, Argentina
- Departamento de Histología, Embriología, Biología Celular y Genética, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, 1121, Argentina
| | - A Montaner
- Instituto de Ciencia y Tecnología "Dr. César Milstein", CONICET, Fundación Pablo Cassará, Buenos Aires, C1440FFX, Argentina
| | - M J Villar
- Instituto de Investigaciones en Medicina Traslacional (IIMT), Universidad Austral-CONICET, Av. Juan D. Perón 1500, Pilar, Buenos Aires, B1629AHJ, Argentina
| | - L Constandil
- Laboratorio de Neurobiología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, 8320000, Chile
| | - Pablo R Brumovsky
- Instituto de Investigaciones en Medicina Traslacional (IIMT), Universidad Austral-CONICET, Av. Juan D. Perón 1500, Pilar, Buenos Aires, B1629AHJ, Argentina.
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