1
|
Corriero A, Giglio M, Soloperto R, Inchingolo F, Varrassi G, Puntillo F. Microbial Symphony: Exploring the Role of the Gut in Osteoarthritis-Related Pain. A Narrative Review. Pain Ther 2024; 13:409-433. [PMID: 38678155 PMCID: PMC11111653 DOI: 10.1007/s40122-024-00602-9] [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: 02/22/2024] [Accepted: 04/03/2024] [Indexed: 04/29/2024] Open
Abstract
One of the most common musculoskeletal disorders, osteoarthritis (OA), causes worldwide disability, morbidity, and poor quality of life by degenerating articular cartilage, modifying subchondral bone, and inflaming synovial membranes. OA pathogenesis pathways must be understood to generate new preventative and disease-modifying therapies. In recent years, it has been acknowledged that gut microbiota (GM) can significantly contribute to the development of OA. Dysbiosis of GM can disrupt the "symphony" between the host and the GM, leading to a host immunological response that activates the "gut-joint" axis, ultimately worsening OA. This narrative review summarizes research supporting the "gut-joint axis" hypothesis, focusing on the interactions between GM and the immune system in its two main components, innate and adaptive immunity. Furthermore, the pathophysiological sequence of events that link GM imbalance to OA and OA-related pain is broken down and further investigated. We also suggest that diet and prebiotics, probiotics, nutraceuticals, exercise, and fecal microbiota transplantation could improve OA management and represent a new potential therapeutic tool in the light of the scarce panorama of disease-modifying osteoarthritis drugs (DMOADs). Future research is needed to elucidate these complex interactions, prioritizing how a particular change in GM, i.e., a rise or a drop of a specific bacterial strain, correlates with a certain OA subset to pinpoint the associated signaling pathway that leads to OA.
Collapse
Affiliation(s)
- Alberto Corriero
- Department of Interdisciplinary Medicine - ICU Section, University of Bari Aldo Moro, Piazza G. Cesare 11, 70124, Bari, Italy.
| | - Mariateresa Giglio
- Department of Interdisciplinary Medicine - ICU Section, University of Bari Aldo Moro, Piazza G. Cesare 11, 70124, Bari, Italy
| | - Rossana Soloperto
- Department of Intensive Care, Brussels' University Hospital (HUB), Rue de Lennik 808, 1070, Brussels, Belgium
| | - Francesco Inchingolo
- Department of Interdisciplinary Medicine, University of Bari "Aldo Moro", 70124, Bari, Italy
| | | | - Filomena Puntillo
- Department of Interdisciplinary Medicine - ICU Section, University of Bari Aldo Moro, Piazza G. Cesare 11, 70124, Bari, Italy.
| |
Collapse
|
2
|
Ford AC, Vanner S, Kashyap PC, Nasser Y. Chronic Visceral Pain: New Peripheral Mechanistic Insights and Resulting Treatments. Gastroenterology 2024; 166:976-994. [PMID: 38325759 PMCID: PMC11102851 DOI: 10.1053/j.gastro.2024.01.045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 11/15/2023] [Accepted: 01/05/2024] [Indexed: 02/09/2024]
Abstract
Chronic visceral pain is one of the most common reasons for patients with gastrointestinal disorders, such as inflammatory bowel disease or disorders of brain-gut interaction, to seek medical attention. It represents a substantial burden to patients and is associated with anxiety, depression, reductions in quality of life, and impaired social functioning, as well as increased direct and indirect health care costs to society. Unfortunately, the diagnosis and treatment of chronic visceral pain is difficult, in part because our understanding of the underlying pathophysiologic basis is incomplete. In this review, we highlight recent advances in peripheral pain signaling and specific physiologic and pathophysiologic preclinical mechanisms that result in the sensitization of peripheral pain pathways. We focus on preclinical mechanisms that have been translated into treatment approaches and summarize the current evidence base for directing treatment toward these mechanisms of chronic visceral pain derived from clinical trials. The effective management of chronic visceral pain remains of critical importance for the quality of life of suffers. A deeper understanding of peripheral pain mechanisms is necessary and may provide the basis for novel therapeutic interventions.
Collapse
Affiliation(s)
- Alexander C Ford
- Leeds Institute of Medical Research at St. James's, University of |Leeds, Leeds, United Kingdom; Leeds Gastroenterology Institute, Leeds Teaching Hospitals National Health Service Trust, Leeds, United Kingdom
| | - Stephen Vanner
- Gastrointestinal Diseases Research Unit, Kingston General Hospital, Queen's University, Kingston, Ontario, Canada
| | - Purna C Kashyap
- Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, Minnesota
| | - Yasmin Nasser
- Snyder Institute for Chronic Diseases, Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
| |
Collapse
|
3
|
Masaud K, Collins JM, Rubio RC, Corrigan M, Cotter PD, O'Brien N, Bluett R, Jimenez CK, O'Mahony SM, Shorten GD. The gut microbiota in persistent post-operative pain following breast cancer surgery. Sci Rep 2024; 14:12401. [PMID: 38811609 PMCID: PMC11137075 DOI: 10.1038/s41598-024-62397-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Accepted: 05/16/2024] [Indexed: 05/31/2024] Open
Abstract
Persistent post-surgical pain (PPSP) is defined as pain which continues after a surgical operation in a significant form for at least three months (and is not related to pre-existing painful conditions). PPSP is a common, under-recognised, and important clinical problem which affects millions of patients worldwide. Preventative measures which are currently available include the selection of a minimally invasive surgical technique and an aggressive multimodal perioperative analgesic regimen. More recently, a role for the gut microbiota in pain modulation has become increasingly apparent. This study aims to investigate any relationship between the gut microbiota and PPSP. A prospective observational study of 68 female adult patients undergoing surgery for management of breast cancer was carried out. Stool samples from 45 of these patients were obtained to analyse the composition of the gut microbiota. Measures of pain and state-trait anxiety were also taken to investigate further dimensions in any relationship between the gut microbiota and PPSP. At 12 weeks postoperatively, 21 patients (51.2%) did not have any pain and 20 patients (48.8%) reported feeling pain that persisted at that time. Analysis of the gut microbiota revealed significantly lower alpha diversity (using three measures) in those patients reporting severe pain at the 60 min post-operative and the 12 weeks post-operative timepoints. A cluster of taxa represented by Bifidobacterium longum, and Faecalibacterium prausnitzii was closely associated with those individuals reporting no pain at 12 weeks postoperatively, while Megamonas hypermegale, Bacteroides pectinophilus, Ruminococcus bromii, and Roseburia hominis clustered relatively closely in the group of patients fulfilling the criteria for persistent post-operative pain. We report for the first time specific associations between the gut microbiota composition and the presence or absence of PPSP. This may provide further insights into mechanisms behind the role of the gut microbiota in the development of PPSP and could inform future treatment strategies.
Collapse
Affiliation(s)
- Khaled Masaud
- Department of Anaesthesia and Intensive Care Medicine, Cork University Hospital and University College Cork, Cork, Ireland
| | - James M Collins
- APC Microbiome Ireland, University College Cork, Cork, Ireland
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - Raul Cabrera Rubio
- APC Microbiome Ireland, University College Cork, Cork, Ireland
- Teagasc Food Research Centre, Moorepark, Fermoy, Cork, Ireland
- Department of Biotechnology, Institute of Agrochemistry and Food Technology-National Research Council (IATA-CSIC), Valencia, Spain
| | - Mark Corrigan
- Cork Breast Research Centre, University College Cork, Cork, Ireland
| | - Paul D Cotter
- APC Microbiome Ireland, University College Cork, Cork, Ireland
- Teagasc Food Research Centre, Moorepark, Fermoy, Cork, Ireland
| | - Niall O'Brien
- Department of Anaesthesia and Intensive Care Medicine, Cork University Hospital and University College Cork, Cork, Ireland
| | - Ronan Bluett
- Department of Anaesthesia and Intensive Care Medicine, Cork University Hospital and University College Cork, Cork, Ireland
| | - Clare Keaveney Jimenez
- Department of Anaesthesia and Intensive Care Medicine, Cork University Hospital and University College Cork, Cork, Ireland
| | - Siobhain M O'Mahony
- APC Microbiome Ireland, University College Cork, Cork, Ireland
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - George D Shorten
- Department of Anaesthesia and Intensive Care Medicine, Cork University Hospital and University College Cork, Cork, Ireland.
| |
Collapse
|
4
|
Rodríguez-Palma EJ, Huerta de la Cruz S, Islas-Espinoza AM, Castañeda-Corral G, Granados-Soto V, Khanna R. Nociplastic pain mechanisms and toll-like receptors as promising targets for its management. Pain 2024:00006396-990000000-00571. [PMID: 38595206 DOI: 10.1097/j.pain.0000000000003238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 02/29/2024] [Indexed: 04/11/2024]
Abstract
ABSTRACT Nociplastic pain, characterized by abnormal pain processing without an identifiable organic cause, affects a significant portion of the global population. Unfortunately, current pharmacological treatments for this condition often prove ineffective, prompting the need to explore new potential targets for inducing analgesic effects in patients with nociplastic pain. In this context, toll-like receptors (TLRs), known for their role in the immune response to infections, represent promising opportunities for pharmacological intervention because they play a relevant role in both the development and maintenance of pain. Although TLRs have been extensively studied in neuropathic and inflammatory pain, their specific contributions to nociplastic pain remain less clear, demanding further investigation. This review consolidates current evidence on the connection between TLRs and nociplastic pain, with a specific focus on prevalent conditions like fibromyalgia, stress-induced pain, sleep deprivation-related pain, and irritable bowel syndrome. In addition, we explore the association between nociplastic pain and psychiatric comorbidities, proposing that modulating TLRs can potentially alleviate both pain syndromes and related psychiatric disorders. Finally, we discuss the potential sex differences in TLR signaling, considering the higher prevalence of nociplastic pain among women. Altogether, this review aims to shed light on nociplastic pain, its underlying mechanisms, and its intriguing relationship with TLR signaling pathways, ultimately framing the potential therapeutic role of TLRs in addressing this challenging condition.
Collapse
Affiliation(s)
- Erick J Rodríguez-Palma
- Department of Pharmacology and Therapeutics, College of Medicine, University of Florida, Gainesville, FL, United States
- Neurobiology of Pain Laboratory, Departamento de Farmacobiología, Cinvestav, South Campus, Mexico City, Mexico
| | | | - Ana M Islas-Espinoza
- Neurobiology of Pain Laboratory, Departamento de Farmacobiología, Cinvestav, South Campus, Mexico City, Mexico
| | | | - Vinicio Granados-Soto
- Neurobiology of Pain Laboratory, Departamento de Farmacobiología, Cinvestav, South Campus, Mexico City, Mexico
| | - Rajesh Khanna
- Department of Pharmacology and Therapeutics, College of Medicine, University of Florida, Gainesville, FL, United States
| |
Collapse
|
5
|
Pak R, Cho M, Pride K, Abd-Elsayed A. The Gut Microbiota and Chronic Pain. Curr Pain Headache Rep 2024; 28:259-269. [PMID: 38345694 DOI: 10.1007/s11916-024-01221-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/30/2024] [Indexed: 03/16/2024]
Abstract
PURPOSE OF REVIEW To examine the effects and interactions between gut microbia and chronic pain. RECENT FINDINGS The gut microbiome has been an area of interest in both the scientific and general audience due to a growing body of evidence suggesting its influence in a variety of health and disease states. Communication between the central nervous system (CNS) and gut microbiome is said to be bidirectional, in what is referred to as the gut-brain axis. Chronic pain is a prevalent costly personal and public health burden and so, there is a vested interest in devising safe and efficacious treatments. Numerous studies, many of which are animal studies, have been conducted to examine the gut microbiome's role in the pathophysiology of chronic pain states, such as neuropathy, inflammation, visceral pain, etc. As the understanding of this relationship grows, so does the potential for therapeutic targeting of the gut microbiome in chronic pain.
Collapse
Affiliation(s)
- Ray Pak
- Department of Physical Medicine and Rehabilitation, New York Medical College/Metropolitan, New York, NY, USA
| | - Michelle Cho
- Department of Physical Medicine and Rehabilitation, New York Medical College/Metropolitan, New York, NY, USA
| | - Keth Pride
- Department of Anesthesiology, University of Wisconsin School of Medicine and Public Health, 600 Highland Avenue, B6/319 CSC, Madison, WI, 53792-3272, USA
| | - Alaa Abd-Elsayed
- Department of Anesthesiology, University of Wisconsin School of Medicine and Public Health, 600 Highland Avenue, B6/319 CSC, Madison, WI, 53792-3272, USA.
| |
Collapse
|
6
|
Rahman SO, Bariguian F, Mobasheri A. The Potential Role of Probiotics in the Management of Osteoarthritis Pain: Current Status and Future Prospects. Curr Rheumatol Rep 2023; 25:307-326. [PMID: 37656392 PMCID: PMC10754743 DOI: 10.1007/s11926-023-01108-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/07/2023] [Indexed: 09/02/2023]
Abstract
PURPOSE OF REVIEW This narrative review article comprehensively explains the pathophysiology of osteoarthritis (OA) pain perception, how the gut microbiota is correlated with it, possible molecular pathways involved in probiotics-mediated OA pain reduction, limitations in the current research approaches, and future perspectives. RECENT FINDINGS The initiation and progression of OA, including the development of chronic pain, is intricately associated with activation of the innate immune system and subsequent inflammatory responses. Trauma, lifestyle (e.g., obesity and metabolic disease), and chronic antibiotic treatment can disrupt commensal homeostasis of the human microbiome, thereby affecting intestinal integrity and promoting leakage of bacterial endotoxins and metabolites such as lipopolysaccharides (LPS) into circulation. Increased level of LPS is associated with knee osteophyte severity and joint pain. Both preclinical and clinical studies strongly suggest that probiotics may benefit patients with OA pain through positive gut microbiota modulation and attenuating low-grade inflammation via multiple pathways. Patent data also suggests increased interest in the development of new innovations that involve probiotic use for reducing OA and joint pain. Recent data suggest that probiotics are attracting more and more attention for OA pain management. The advancement of knowledge in this area may pave the way for developing different probiotic strains that can be used to support joint health, improve treatment outcomes in OA, and reduce the huge impact of the disease on healthcare systems worldwide.
Collapse
Affiliation(s)
| | - Frédérique Bariguian
- Haleon (Formerly GSK Consumer Healthcare), Route de L'Etraz 2, Case Postale 1279, 1260, Nyon 1, Switzerland.
| | - Ali Mobasheri
- Research Unit of Health Sciences and Technology, Faculty of Medicine, University of Oulu, 90014, Oulu, FI, Finland.
- Department of Regenerative Medicine, State Research Institute Centre for Innovative Medicine, Vilnius, Lithuania.
- Department of Joint Surgery, First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China.
- World Health Organization Collaborating Centre for Public Health Aspects of Musculoskeletal Health and Aging, Liege, Belgium.
| |
Collapse
|
7
|
Gauthier MM, Hayoz S, Banek CT. Neuroimmune interplay in kidney health and disease: Role of renal nerves. Auton Neurosci 2023; 250:103133. [PMID: 38061177 PMCID: PMC10748436 DOI: 10.1016/j.autneu.2023.103133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 11/15/2023] [Accepted: 11/22/2023] [Indexed: 12/18/2023]
Abstract
Renal nerves and their role in physiology and disease have been a topic of increasing interest in the past few decades. Renal inflammation contributes to many cardiorenal disease conditions, including hypertension, chronic kidney disease, and polycystic kidney disease. Much is known about the role of renal sympathetic nerves in physiology - they contribute to the regulation of sodium reabsorption, renin release, and renal vascular resistance. In contrast, far less is known about afferent, or "sensory," renal nerves, which convey signals from the kidney to the brain. While much remains unknown about these nerves in the context of normal physiology, even less is known about their contribution to disease states. Furthermore, it has become apparent that the crosstalk between renal nerves and the immune system may augment or modulate disease. Research from other fields, especially pain research, has provided critical insight into neuroimmune crosstalk. Sympathetic renal nerve activity may increase immune cell recruitment, but far less work has been done investigating the interplay between afferent renal nerves and the immune system. Evidence from other fields suggests that inflammation may augment afferent renal nerve activity. Furthermore, these nerves may exacerbate renal inflammation through the release of afferent-specific neurotransmitters.
Collapse
Affiliation(s)
- Madeline M Gauthier
- Department of Physiology, University of Arizona Health Sciences Center, Tucson, AZ, USA
| | - Sebastien Hayoz
- Department of Physiology, University of Arizona Health Sciences Center, Tucson, AZ, USA
| | - Christopher T Banek
- Department of Physiology, University of Arizona Health Sciences Center, Tucson, AZ, USA.
| |
Collapse
|
8
|
Lu G, Zhang S, Wang R, Zhang Z, Wang W, Wen Q, Zhang F, Li P. Global Trends in Research of Pain-Gut-Microbiota Relationship and How Nutrition Can Modulate This Link. Nutrients 2023; 15:3704. [PMID: 37686738 PMCID: PMC10490108 DOI: 10.3390/nu15173704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 08/21/2023] [Accepted: 08/22/2023] [Indexed: 09/10/2023] Open
Abstract
INTRODUCTION The link between gut microbiota and chronic painful conditions has recently gained attention. Nutrition, as a common intervention in daily life and medical practice, is closely related to microbiota and pain. However, no published bibliometric reports have analyzed the scientific literature concerning the link. METHODS AND RESULTS We used bibliometrics to identify the characteristics of the global scientific output over the past 20 years. We also aimed to capture and describe how nutrition can modulate the abovementioned link. Relevant papers were searched in the Web of Science database. All necessary publication and citation data were acquired and exported to Bibliometrix for further analyses. The keywords mentioned were illustrated using visualization maps. In total, 1551 papers shed light on the relationship from 2003 to 2022. However, only 122 papers discussed how nutritional interventions can modulate this link. The citations and attention were concentrated on the gut microbiota, pain, and probiotics in terms of the pain-gut relationship. Nutritional status has gained attention in motor themes of a thematic map. CONCLUSIONS This bibliometric analysis was applied to identify the scientific literature linking gut microbiota, chronic painful conditions, and nutrition, revealing the popular research topics and authors, scientific institutions, countries, and journals in this field. This study enriches the evidence moving boundaries of microbiota medicine as a clinical medicine.
Collapse
Affiliation(s)
- Gaochen Lu
- Department of Microbiota Medicine, Medical Center for Digestive Diseases, The Second Affiliated Hospital of Nanjing Medical University, Nanjing 210011, China; (G.L.); (S.Z.); (R.W.); (Z.Z.); (W.W.); (Q.W.)
- Key Lab of Holistic Integrative Enterology, Nanjing Medical University, Nanjing 210011, China
| | - Sheng Zhang
- Department of Microbiota Medicine, Medical Center for Digestive Diseases, The Second Affiliated Hospital of Nanjing Medical University, Nanjing 210011, China; (G.L.); (S.Z.); (R.W.); (Z.Z.); (W.W.); (Q.W.)
- Key Lab of Holistic Integrative Enterology, Nanjing Medical University, Nanjing 210011, China
| | - Rui Wang
- Department of Microbiota Medicine, Medical Center for Digestive Diseases, The Second Affiliated Hospital of Nanjing Medical University, Nanjing 210011, China; (G.L.); (S.Z.); (R.W.); (Z.Z.); (W.W.); (Q.W.)
- Key Lab of Holistic Integrative Enterology, Nanjing Medical University, Nanjing 210011, China
| | - Zulun Zhang
- Department of Microbiota Medicine, Medical Center for Digestive Diseases, The Second Affiliated Hospital of Nanjing Medical University, Nanjing 210011, China; (G.L.); (S.Z.); (R.W.); (Z.Z.); (W.W.); (Q.W.)
- Key Lab of Holistic Integrative Enterology, Nanjing Medical University, Nanjing 210011, China
| | - Weihong Wang
- Department of Microbiota Medicine, Medical Center for Digestive Diseases, The Second Affiliated Hospital of Nanjing Medical University, Nanjing 210011, China; (G.L.); (S.Z.); (R.W.); (Z.Z.); (W.W.); (Q.W.)
- Key Lab of Holistic Integrative Enterology, Nanjing Medical University, Nanjing 210011, China
| | - Quan Wen
- Department of Microbiota Medicine, Medical Center for Digestive Diseases, The Second Affiliated Hospital of Nanjing Medical University, Nanjing 210011, China; (G.L.); (S.Z.); (R.W.); (Z.Z.); (W.W.); (Q.W.)
- Key Lab of Holistic Integrative Enterology, Nanjing Medical University, Nanjing 210011, China
| | - Faming Zhang
- Department of Microbiota Medicine, Medical Center for Digestive Diseases, The Second Affiliated Hospital of Nanjing Medical University, Nanjing 210011, China; (G.L.); (S.Z.); (R.W.); (Z.Z.); (W.W.); (Q.W.)
- Key Lab of Holistic Integrative Enterology, Nanjing Medical University, Nanjing 210011, China
- Department of Microbiotherapy, Sir Run Run Hospital, Nanjing Medical University, Nanjing 211166, China
- National Clinical Research Center for Digestive Diseases, Xi’an 710032, China
| | - Pan Li
- Department of Microbiota Medicine, Medical Center for Digestive Diseases, The Second Affiliated Hospital of Nanjing Medical University, Nanjing 210011, China; (G.L.); (S.Z.); (R.W.); (Z.Z.); (W.W.); (Q.W.)
- Key Lab of Holistic Integrative Enterology, Nanjing Medical University, Nanjing 210011, China
| |
Collapse
|
9
|
Gore R, Esmail T, Pflepsen K, Marron Fernandez de Velasco E, Kitto KF, Riedl MS, Karlen A, McIvor RS, Honda CN, Fairbanks CA, Vulchanova L. AAV-mediated gene transfer to colon-innervating primary afferent neurons. FRONTIERS IN PAIN RESEARCH 2023; 4:1225246. [PMID: 37599864 PMCID: PMC10436501 DOI: 10.3389/fpain.2023.1225246] [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: 05/19/2023] [Accepted: 07/25/2023] [Indexed: 08/22/2023] Open
Abstract
Investigation of neural circuits underlying visceral pain is hampered by the difficulty in achieving selective manipulations of individual circuit components. In this study, we adapted a dual AAV approach, used for projection-specific transgene expression in the CNS, to explore the potential for targeted delivery of transgenes to primary afferent neurons innervating visceral organs. Focusing on the extrinsic sensory innervation of the mouse colon, we first characterized the extent of dual transduction following intrathecal delivery of one AAV9 vector and intracolonic delivery of a second AAV9 vector. We found that if the two AAV9 vectors were delivered one week apart, dorsal root ganglion (DRG) neuron transduction by the second vector was greatly diminished. Following delivery of the two viruses on the same day, we observed colocalization of the transgenes in DRG neurons, indicating dual transduction. Next, we delivered intrathecally an AAV9 vector encoding the inhibitory chemogenetic actuator hM4D(Gi) in a Cre-recombinase dependent manner, and on the same day injected an AAV9 vector carrying Cre-recombinase in the colon. DRG expression of hM4D(Gi) was demonstrated at the mRNA and protein level. However, we were unable to demonstrate selective inhibition of visceral nociception following hM4D(Gi) activation. Taken together, these results establish a foundation for development of strategies for targeted transduction of primary afferent neurons for neuromodulation of peripheral neural circuits.
Collapse
Affiliation(s)
- Reshma Gore
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, United States
| | - Tina Esmail
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, United States
| | - Kelsey Pflepsen
- Department of Pharmaceutics, University of Minnesota, Minneapolis, MN, United States
| | | | - Kelley F. Kitto
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, United States
| | - Maureen S. Riedl
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, United States
| | - Andrea Karlen
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, United States
| | - R. Scott McIvor
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, United States
| | - Christopher N. Honda
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, United States
| | - Carolyn A. Fairbanks
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, United States
- Department of Pharmaceutics, University of Minnesota, Minneapolis, MN, United States
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, United States
| | - Lucy Vulchanova
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, United States
| |
Collapse
|
10
|
Millet A, Jendzjowsky N. Pathogen recognition by sensory neurons: hypotheses on the specificity of sensory neuron signaling. Front Immunol 2023; 14:1184000. [PMID: 37207232 PMCID: PMC10189129 DOI: 10.3389/fimmu.2023.1184000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 04/19/2023] [Indexed: 05/21/2023] Open
Abstract
Sensory neurons cooperate with barrier tissues and resident immune cells to form a significant aspect of defensive strategies in concert with the immune system. This assembly of neuroimmune cellular units is exemplified across evolution from early metazoans to mammalian life. As such, sensory neurons possess the capability to detect pathogenic infiltrates at barrier surfaces. This capacity relies on mechanisms that unleash specific cell signaling, trafficking and defensive reflexes. These pathways exploit mechanisms to amplify and enhance the alerting response should pathogenic infiltration seep into other tissue compartments and/or systemic circulation. Here we explore two hypotheses: 1) that sensory neurons' potential cellular signaling pathways require the interaction of pathogen recognition receptors and ion channels specific to sensory neurons and; 2) mechanisms which amplify these sensing pathways require activation of multiple sensory neuron sites. Where possible, we provide references to other apt reviews which provide the reader more detail on specific aspects of the perspectives provided here.
Collapse
Affiliation(s)
- Antoine Millet
- Respiratory & Exercise Physiology, The Lundquist Institute for Biomedical Innovation at Harbor University of California Los Angeles (UCLA) Medical Center, Torrance, CA, United States
| | - Nicholas Jendzjowsky
- Respiratory & Exercise Physiology, The Lundquist Institute for Biomedical Innovation at Harbor University of California Los Angeles (UCLA) Medical Center, Torrance, CA, United States
- Division of Respiratory and Critical Care Medicine and Physiology, David Geffen School of Medicine, University of California Los Angeles (UCLA), Los Angeles, CA, United States
- *Correspondence: Nicholas Jendzjowsky,
| |
Collapse
|
11
|
Yadav S, Singh A, Kant R, Surolia A. TLR4 activation by lysozyme induces pain without inflammation. Front Immunol 2023; 14:1065226. [PMID: 37197666 PMCID: PMC10183575 DOI: 10.3389/fimmu.2023.1065226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Accepted: 04/18/2023] [Indexed: 05/19/2023] Open
Abstract
Mostly, pain has been studied in association with inflammation, until recent studies which indicate that during bacterial infections, pain mechanisms could be independent of the inflammation. Chronic pain can sustain long after the healing from the injury, even in the absence of any visible inflammation. However, the mechanism behind this is not known. We tested inflammation in lysozyme-injected mice foot paw. Interestingly, we observed no inflammation in mice foot paw. Yet, lysozyme injections induced pain in these mice. Lysozyme induces pain in a TLR4-dependent manner and TLR4 activation by its ligands such as LPS leads to inflammatory response. We compared the intracellular signaling of MyD88 and TRIF pathways upon TLR4 activation by lysozyme and LPS to understand the underlying mechanism behind the absence of an inflammatory response upon lysozyme treatment. We observed a TLR4 induced selective TRIF and not MyD88 pathway activation upon lysozyme treatment. This is unlike any other previously known endogenous TLR4 activators. A selective activation of TRIF pathway by lysozyme induces weak inflammatory cytokine response devoid of inflammation. However, lysozyme activates glutamate oxaloacetate transaminase-2 (GOT2) in neurons in a TRIF-dependent manner, resulting in enhanced glutamate response. We propose that this enhanced glutaminergic response could lead to neuronal activation resulting in pain sensation upon lysozyme injections. Collectively we identify that TLR4 activation by lysozyme can induce pain in absence of a significant inflammation. Also, unlike other known TLR4 endogenous activators, lysozyme does not activate MyD88 signaling. These findings uncover a mechanism of selective activation of TRIF pathway by TLR4. This selective TRIF activation induces pain with negligible inflammation, constituting a chronic pain homeostatic mechanism.
Collapse
Affiliation(s)
- Saurabh Yadav
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
| | - Amrita Singh
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
| | - Ravi Kant
- Institute of Science, Nirma University, Ahmedabad, India
| | - Avadhesha Surolia
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
- *Correspondence: Avadhesha Surolia,
| |
Collapse
|
12
|
Chen Y, Chen H, Li XC, Mi WL, Chu YX, Wang YQ, Mao-Ying QL. Neuronal toll like receptor 9 contributes to complete Freund’s adjuvant-induced inflammatory pain in mice. Front Mol Neurosci 2022; 15:1008203. [PMID: 36277489 PMCID: PMC9582929 DOI: 10.3389/fnmol.2022.1008203] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 09/12/2022] [Indexed: 11/13/2022] Open
Abstract
Toll like receptor 9 (TLR9) is a critical sensor for danger-associated molecular patterns (DAMPs) and a crucial marker of non-sterile/sterile inflammation among all TLRs. However, the significance of TLR9 in inflammatory pain remains unclear. Here, we subcutaneously injected Complete Freund’s adjuvant (CFA) into the plantar surface of the hind paw, to established a mouse model of inflammatory pain, and we examined expression and distribution of TLR9 in this model. There was a significant increase of TLR9 mRNA and reduction of mechanical paw withdrawal threshold in mice intraplantar injected with CFA. By contrast, mechanical paw withdrawal threshold significantly increased in mice treated with TLR9 antagonist ODN2088. Furthermore, TLR9 is found predominantly distributed in the neurons by immunofluorescence experiment. Accordingly, neuronal TLR9 downregulation in the spinal cord prevented CFA-induced persistent hyperalgesia. Overall, these findings indicate that neuronal TLR9 in the spinal cord is closely related to CFA-induced inflammatory pain. It provides a potential treatment option for CFA-induced inflammatory pain by applying TLR9 antagonist.
Collapse
Affiliation(s)
- Yu Chen
- Department of Integrative Medicine and Neurobiology, School of Basic Medical Sciences, Shanghai Medical College, Institute of Acupuncture Research, Institutes of Integrative Medicine, Fudan University, Shanghai, China
| | - Hui Chen
- Department of Integrative Medicine and Neurobiology, School of Basic Medical Sciences, Shanghai Medical College, Institute of Acupuncture Research, Institutes of Integrative Medicine, Fudan University, Shanghai, China
| | - Xiao-Chen Li
- Department of Integrative Medicine and Neurobiology, School of Basic Medical Sciences, Shanghai Medical College, Institute of Acupuncture Research, Institutes of Integrative Medicine, Fudan University, Shanghai, China
| | - Wen-Li Mi
- Department of Integrative Medicine and Neurobiology, School of Basic Medical Sciences, Shanghai Medical College, Institute of Acupuncture Research, Institutes of Integrative Medicine, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Acupuncture Mechanism and Acupoint Function, Fudan University, Shanghai, China
| | - Yu-Xia Chu
- Department of Integrative Medicine and Neurobiology, School of Basic Medical Sciences, Shanghai Medical College, Institute of Acupuncture Research, Institutes of Integrative Medicine, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Acupuncture Mechanism and Acupoint Function, Fudan University, Shanghai, China
| | - Yan-Qing Wang
- Department of Integrative Medicine and Neurobiology, School of Basic Medical Sciences, Shanghai Medical College, Institute of Acupuncture Research, Institutes of Integrative Medicine, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Acupuncture Mechanism and Acupoint Function, Fudan University, Shanghai, China
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Qi-Liang Mao-Ying
- Department of Integrative Medicine and Neurobiology, School of Basic Medical Sciences, Shanghai Medical College, Institute of Acupuncture Research, Institutes of Integrative Medicine, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Acupuncture Mechanism and Acupoint Function, Fudan University, Shanghai, China
- *Correspondence: Qi-Liang Mao-Ying,
| |
Collapse
|
13
|
Liu X, Yang W, Zhu C, Sun S, Wu S, Wang L, Wang Y, Ge Z. Toll-like receptors and their role in neuropathic pain and migraine. Mol Brain 2022; 15:73. [PMID: 35987639 PMCID: PMC9392297 DOI: 10.1186/s13041-022-00960-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Accepted: 08/11/2022] [Indexed: 11/10/2022] Open
Abstract
Migraine is a complex neurological disease of unknown etiology involving both genetic and environmental factors. It has previously been reported that persistent pain may be mediated by the immune and inflammatory systems. Toll-like receptors (TLRs) play a significant role in immune and inflammatory responses and are expressed by microglia and astrocytes. One of the fundamental mechanisms of the innate immune system in coordinating inflammatory signal transduction is through TLRs, which protect the host organism by initiating inflammatory signaling cascades in response to tissue damage or stress. TLRs reside at the neuroimmune interface, and accumulating evidence has suggested that the inflammatory consequences of TLR activation on glia (mainly microglia and astrocytes), sensory neurons, and other cell types can influence nociceptive processing and lead to pain. Several studies have shown that TLRs may play a key role in neuropathic pain and migraine etiology by activating the microglia. The pathogenesis of migraine may involve a TLR-mediated crosstalk between neurons and immune cells. Innate responses in the central nervous system (CNS) occur during neuroinflammatory phenomena, including migraine. Antigens found in the environment play a crucial role in the inflammatory response, causing a broad range of diseases, including migraines. These can be recognized by several innate immune cells, including macrophages, microglia, and dendritic cells, and can be activated through TLR signaling. Given the prevalence of migraine and the insufficient efficacy and safety of current treatment options, a deeper understanding of TLRs is expected to provide novel therapies for managing chronic migraine. This review aimed to justify the view that TLRs may be involved in migraine.
Collapse
|
14
|
Lysophosphatidylcholine: Potential Target for the Treatment of Chronic Pain. Int J Mol Sci 2022; 23:ijms23158274. [PMID: 35955410 PMCID: PMC9368269 DOI: 10.3390/ijms23158274] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 07/22/2022] [Accepted: 07/23/2022] [Indexed: 12/26/2022] Open
Abstract
The bioactive lipid lysophosphatidylcholine (LPC), a major phospholipid component of oxidized low-density lipoprotein (Ox-LDL), originates from the cleavage of phosphatidylcholine by phospholipase A2 (PLA2) and is catabolized to other substances by different enzymatic pathways. LPC exerts pleiotropic effects mediated by its receptors, G protein-coupled signaling receptors, Toll-like receptors, and ion channels to activate several second messengers. Lysophosphatidylcholine (LPC) is increasingly considered a key marker/factor positively in pathological states, especially inflammation and atherosclerosis development. Current studies have indicated that the injury of nervous tissues promotes oxidative stress and lipid peroxidation, as well as excessive accumulation of LPC, enhancing the membrane hyperexcitability to induce chronic pain, which may be recognized as one of the hallmarks of chronic pain. However, findings from lipidomic studies of LPC have been lacking in the context of chronic pain. In this review, we focus in some detail on LPC sources, biochemical pathways, and the signal-transduction system. Moreover, we outline the detection methods of LPC for accurate analysis of each individual LPC species and reveal the pathophysiological implication of LPC in chronic pain, which makes it an interesting target for biomarkers and the development of medicine regarding chronic pain.
Collapse
|
15
|
Acioglu C, Heary RF, Elkabes S. Roles of neuronal toll-like receptors in neuropathic pain and central nervous system injuries and diseases. Brain Behav Immun 2022; 102:163-178. [PMID: 35176442 DOI: 10.1016/j.bbi.2022.02.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 01/12/2022] [Accepted: 02/11/2022] [Indexed: 12/12/2022] Open
Abstract
Toll-like receptors (TLRs) are innate immune receptors that are expressed in immune cells as well as glia and neurons of the central and peripheral nervous systems. They are best known for their role in the host defense in response to pathogens and for the induction of inflammation in infectious and non-infectious diseases. In the central nervous system (CNS), TLRs modulate glial and neuronal functions as well as innate immunity and neuroinflammation under physiological or pathophysiological conditions. The majority of the studies on TLRs in CNS pathologies investigated their overall contribution without focusing on a particular cell type, or they analyzed TLRs in glia and infiltrating immune cells in the context of neuroinflammation and cellular activation. The role of neuronal TLRs in CNS diseases and injuries has received little attention and remains underappreciated. The primary goal of this review is to summarize findings demonstrating the pivotal and unique roles of neuronal TLRs in neuropathic pain, Alzheimer's disease, Parkinson's disease and CNS injuries. We discuss how the current findings warrant future investigations to better define the specific contributions of neuronal TLRs to these pathologies. We underline the paucity of information regarding the role of neuronal TLRs in other neurodegenerative, demyelinating, and psychiatric diseases. We draw attention to the importance of broadening research on neuronal TLRs in view of emerging evidence demonstrating their distinctive functional properties.
Collapse
Affiliation(s)
- Cigdem Acioglu
- The Reynolds Family Spine Laboratory, Department of Neurosurgery, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, United States
| | - Robert F Heary
- Department of Neurological Surgery, Hackensack Meridian School of Medicine, Mountainside Medical Center, Montclair, NJ 07042, United States
| | - Stella Elkabes
- The Reynolds Family Spine Laboratory, Department of Neurosurgery, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, United States.
| |
Collapse
|
16
|
Roversi K, Callai-Silva N, Roversi K, Griffith M, Boutopoulos C, Prediger RD, Talbot S. Neuro-Immunity and Gut Dysbiosis Drive Parkinson's Disease-Induced Pain. Front Immunol 2021; 12:759679. [PMID: 34868000 PMCID: PMC8637106 DOI: 10.3389/fimmu.2021.759679] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 10/21/2021] [Indexed: 12/12/2022] Open
Abstract
Parkinson's disease (PD) is the second most common neurodegenerative disorder, affecting 1-2% of the population aged 65 and over. Additionally, non-motor symptoms such as pain and gastrointestinal dysregulation are also common in PD. These impairments might stem from a dysregulation within the gut-brain axis that alters immunity and the inflammatory state and subsequently drives neurodegeneration. There is increasing evidence linking gut dysbiosis to the severity of PD's motor symptoms as well as to somatosensory hypersensitivities. Altogether, these interdependent features highlight the urgency of reviewing the links between the onset of PD's non-motor symptoms and gut immunity and whether such interplays drive the progression of PD. This review will shed light on maladaptive neuro-immune crosstalk in the context of gut dysbiosis and will posit that such deleterious interplays lead to PD-induced pain hypersensitivity.
Collapse
Affiliation(s)
- Katiane Roversi
- Département de Pharmacologie et Physiologie, Université de Montréal, Montréal, QC, Canada.,Centre de Recherche Hôpital Maisonneuve-Rosemont, Montréal, QC, Canada.,Département d'Ophtalmologie, Université de Montréal, Montréal, QC, Canada.,Departamento de Farmacologia, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Natalia Callai-Silva
- Département de Pharmacologie et Physiologie, Université de Montréal, Montréal, QC, Canada.,Centre de Recherche Hôpital Maisonneuve-Rosemont, Montréal, QC, Canada.,Département d'Ophtalmologie, Université de Montréal, Montréal, QC, Canada
| | - Karine Roversi
- Département de Pharmacologie et Physiologie, Université de Montréal, Montréal, QC, Canada
| | - May Griffith
- Centre de Recherche Hôpital Maisonneuve-Rosemont, Montréal, QC, Canada.,Département d'Ophtalmologie, Université de Montréal, Montréal, QC, Canada
| | - Christos Boutopoulos
- Centre de Recherche Hôpital Maisonneuve-Rosemont, Montréal, QC, Canada.,Département d'Ophtalmologie, Université de Montréal, Montréal, QC, Canada
| | - Rui Daniel Prediger
- Departamento de Farmacologia, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Sébastien Talbot
- Département de Pharmacologie et Physiologie, Université de Montréal, Montréal, QC, Canada
| |
Collapse
|
17
|
Toll-Like Receptors (TLRs) and their potential therapeutic applications in diabetic neuropathy. Int Immunopharmacol 2021; 102:108398. [PMID: 34863652 DOI: 10.1016/j.intimp.2021.108398] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 11/03/2021] [Accepted: 11/19/2021] [Indexed: 02/08/2023]
Abstract
One of the most common diabetic microvascular complications is diabetic neuropathy (DN). Immune cell infiltration in the peripheral nerve system (PNS), myelin loss, Schwann cell death, and axonal damage are all hallmarks of DN, which is currently believed to be a chronic inflammatory disease. Toll-like receptors (TLRs) are found in various types of nervous system cells, including Schwann cells, microglia, oligodendrocytes, astrocytes, and neurons. Proinflammatory mediators released at the end of TLR signal transduction can trigger an inflammatory response involving the nervous system. Studies on the association between TLRs and DN began as early as 2004. Since then, several studies have been conducted to assess the involvement of TLRs in the pathogenesis of DN. The focus of this review is to give a complete summary of the researches that have been done in this context, as well as an overview of the role of TLRs and their therapeutic applications in DN.
Collapse
|
18
|
Malfait F, Colman M, Vroman R, De Wandele I, Rombaut L, Miller RE, Malfait AM, Syx D. Pain in the Ehlers-Danlos syndromes: Mechanisms, models, and challenges. AMERICAN JOURNAL OF MEDICAL GENETICS. PART C, SEMINARS IN MEDICAL GENETICS 2021; 187:429-445. [PMID: 34797601 DOI: 10.1002/ajmg.c.31950] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 10/17/2021] [Accepted: 10/22/2021] [Indexed: 12/27/2022]
Abstract
Chronic pain is one of the most common, yet poorly studied, complaints in people suffering from Ehlers-Danlos syndromes (EDS). This heterogeneous group of heritable connective tissue disorders is typically characterized by skin hyperextensibility, joint hypermobility, and generalized connective tissue fragility. Most EDS types are caused by genetic defects that affect connective tissue biosynthesis, thereby compromising collagen biosynthesis or fibrillogenesis and resulting in a disorganized extracellular matrix. Even though chronic pain is a major source of disability, functional impairment, and psychosocial suffering in EDS, currently used analgesics and other treatment strategies provide inadequate pain relief and thus represents an important unmet medical need. An important contributor to this is the lack of knowledge about the underlying mechanisms. In this narrative review, we summarize the current understanding of pain and the associated mechanisms in EDS based on clinical studies focusing on questionnaires and experimental pain testing as well as studies in animal models of EDS. In addition, we highlight the challenges, gaps, and opportunities in EDS-pain research.
Collapse
Affiliation(s)
- Fransiska Malfait
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium.,Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
| | - Marlies Colman
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium.,Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
| | - Robin Vroman
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium.,Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
| | - Inge De Wandele
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium.,Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
| | - Lies Rombaut
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium.,Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
| | - Rachel E Miller
- Division of Rheumatology, Rush University Medical Center, Chicago, Illinois, USA
| | - Anne-Marie Malfait
- Division of Rheumatology, Rush University Medical Center, Chicago, Illinois, USA
| | - Delfien Syx
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium.,Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
| |
Collapse
|
19
|
Guo CJ, Grabinski NS, Liu Q. Peripheral Mechanisms of Itch. J Invest Dermatol 2021; 142:31-41. [PMID: 34838258 DOI: 10.1016/j.jid.2021.10.024] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 10/15/2021] [Accepted: 10/26/2021] [Indexed: 12/30/2022]
Abstract
Itch is a universally experienced sensation, and chronic itch can be as diabolically debilitating as pain. Recent advances have not only identified the neuronal itch sensing circuitry, but also have uncovered the intricate interactions between skin and immune cells that work together with neurons to identify itch-inducing irritants. In this review, we will summarize the fundamental mechanisms of acute itch detection in the skin, as well as highlight the recent discoveries relating to this topic.
Collapse
Affiliation(s)
- Changxiong J Guo
- Center for the Study of Itch & Sensory Disorders, Department of Anesthesiology, School of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Nathaniel S Grabinski
- Center for the Study of Itch & Sensory Disorders, Department of Anesthesiology, School of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Qin Liu
- Center for the Study of Itch & Sensory Disorders, Department of Anesthesiology, School of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA.
| |
Collapse
|
20
|
Neuro-immune-metabolism: The tripod system of homeostasis. Immunol Lett 2021; 240:77-97. [PMID: 34655659 DOI: 10.1016/j.imlet.2021.10.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 09/30/2021] [Accepted: 10/08/2021] [Indexed: 11/20/2022]
Abstract
Homeostatic regulation of cellular and molecular processes is essential for the efficient physiological functioning of body organs. It requires an intricate balance of several networks throughout the body, most notable being the nervous, immune and metabolic systems. Several studies have reported the interactions between neuro-immune, immune-metabolic and neuro-metabolic pathways. Current review aims to integrate the information and show that neuro, immune and metabolic systems form the triumvirate of homeostasis. It focuses on the cellular and molecular interactions occurring in the extremities and intestine, which are innervated by the peripheral nervous system and for the intestine in particular the enteric nervous system. While the interdependence of neuro-immune-metabolic pathways provides a fallback mechanism in case of disruption of homeostasis, in chronic pathologies of continued disequilibrium, the collapse of one system spreads to the other interacting networks as well. Current review illustrates this domino-effect using diabetes as the main example. Together, this review attempts to provide a holistic picture of the integrated network of neuro-immune-metabolism and attempts to broaden the outlook when devising a scientific study or a treatment strategy.
Collapse
|
21
|
Proskocil BJ, Wai K, Lebold KM, Norgard MA, Michaelis KA, De La Torre U, Cook M, Marks DL, Fryer AD, Jacoby DB, Drake MG. TLR7 is expressed by support cells, but not sensory neurons, in ganglia. J Neuroinflammation 2021; 18:209. [PMID: 34530852 PMCID: PMC8447680 DOI: 10.1186/s12974-021-02269-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Accepted: 08/31/2021] [Indexed: 11/10/2022] Open
Abstract
Background Toll-like receptor 7 (TLR7) is an innate immune receptor that detects viral single-stranded RNA and triggers the production of proinflammatory cytokines and type 1 interferons in immune cells. TLR7 agonists also modulate sensory nerve function by increasing neuronal excitability, although studies are conflicting whether sensory neurons specifically express TLR7. This uncertainty has confounded the development of a mechanistic understanding of TLR7 function in nervous tissues. Methods TLR7 expression was tested using in situ hybridization with species-specific RNA probes in vagal and dorsal root sensory ganglia in wild-type and TLR7 knockout (KO) mice and in guinea pigs. Since TLR7 KO mice were generated by inserting an Escherichia coli lacZ gene in exon 3 of the mouse TLR7 gene, wild-type and TLR7 (KO) mouse vagal ganglia were also labeled for lacZ. In situ labeling was compared to immunohistochemistry using TLR7 antibody probes. The effects of influenza A infection on TLR7 expression in sensory ganglia and in the spleen were also assessed. Results In situ probes detected TLR7 in the spleen and in small support cells adjacent to sensory neurons in the dorsal root and vagal ganglia in wild-type mice and guinea pigs, but not in TLR7 KO mice. TLR7 was co-expressed with the macrophage marker Iba1 and the satellite glial cell marker GFAP, but not with the neuronal marker PGP9.5, indicating that TLR7 is not expressed by sensory nerves in either vagal or dorsal root ganglia in mice or guinea pigs. In contrast, TLR7 antibodies labeled small- and medium-sized neurons in wild-type and TLR7 KO mice in a TLR7-independent manner. Influenza A infection caused significant weight loss and upregulation of TLR7 in the spleens, but not in vagal ganglia, in mice. Conclusion TLR7 is expressed by macrophages and satellite glial cells, but not neurons in sensory ganglia suggesting TLR7’s neuromodulatory effects are mediated indirectly via activation of neuronally-associated support cells, not through activation of neurons directly. Our data also suggest TLR7’s primary role in neuronal tissues is not related to antiviral immunity. Supplementary Information The online version contains supplementary material available at 10.1186/s12974-021-02269-x.
Collapse
Affiliation(s)
- Becky J Proskocil
- Division of Pulmonary and Critical Care Medicine, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, UHN67, Portland, OR, 97239, USA
| | - Karol Wai
- Division of Pulmonary and Critical Care Medicine, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, UHN67, Portland, OR, 97239, USA
| | - Katherine M Lebold
- Division of Pulmonary and Critical Care Medicine, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, UHN67, Portland, OR, 97239, USA
| | - Mason A Norgard
- Papé Family Pediatric Research Institute, Oregon Health & Science University, Portland, OR, USA
| | - Katherine A Michaelis
- Papé Family Pediatric Research Institute, Oregon Health & Science University, Portland, OR, USA
| | - Ubaldo De La Torre
- Division of Pulmonary and Critical Care Medicine, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, UHN67, Portland, OR, 97239, USA
| | - Madeline Cook
- Division of Pulmonary and Critical Care Medicine, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, UHN67, Portland, OR, 97239, USA
| | - Daniel L Marks
- Papé Family Pediatric Research Institute, Oregon Health & Science University, Portland, OR, USA
| | - Allison D Fryer
- Division of Pulmonary and Critical Care Medicine, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, UHN67, Portland, OR, 97239, USA
| | - David B Jacoby
- Division of Pulmonary and Critical Care Medicine, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, UHN67, Portland, OR, 97239, USA
| | - Matthew G Drake
- Division of Pulmonary and Critical Care Medicine, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, UHN67, Portland, OR, 97239, USA.
| |
Collapse
|
22
|
Gershon MD, Margolis KG. The gut, its microbiome, and the brain: connections and communications. J Clin Invest 2021; 131:143768. [PMID: 34523615 PMCID: PMC8439601 DOI: 10.1172/jci143768] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Modern research on gastrointestinal behavior has revealed it to be a highly complex bidirectional process in which the gut sends signals to the brain, via spinal and vagal visceral afferent pathways, and receives sympathetic and parasympathetic inputs. Concomitantly, the enteric nervous system within the bowel, which contains intrinsic primary afferent neurons, interneurons, and motor neurons, also senses the enteric environment and controls the detailed patterns of intestinal motility and secretion. The vast microbiome that is resident within the enteric lumen is yet another contributor, not only to gut behavior, but to the bidirectional signaling process, so that the existence of a microbiota-gut-brain "connectome" has become apparent. The interaction between the microbiota, the bowel, and the brain now appears to be neither a top-down nor a bottom-up process. Instead, it is an ongoing, tripartite conversation, the outline of which is beginning to emerge and is the subject of this Review. We emphasize aspects of the exponentially increasing knowledge of the microbiota-gut-brain "connectome" and focus attention on the roles that serotonin, Toll-like receptors, and macrophages play in signaling as exemplars of potentially generalizable mechanisms.
Collapse
Affiliation(s)
| | - Kara Gross Margolis
- Department of Pediatrics, Columbia University Vagelos College of Physicians and Surgeons, New York, New York, USA
| |
Collapse
|
23
|
Dubový P, Hradilová-Svíženská I, Brázda V, Joukal M. Toll-Like Receptor 9-Mediated Neuronal Innate Immune Reaction Is Associated with Initiating a Pro-Regenerative State in Neurons of the Dorsal Root Ganglia Non-Associated with Sciatic Nerve Lesion. Int J Mol Sci 2021; 22:ijms22147446. [PMID: 34299065 PMCID: PMC8304752 DOI: 10.3390/ijms22147446] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 07/07/2021] [Accepted: 07/08/2021] [Indexed: 12/27/2022] Open
Abstract
One of the changes brought about by Wallerian degeneration distal to nerve injury is disintegration of axonal mitochondria and consequent leakage of mitochondrial DNA (mtDNA)—the natural ligand for the toll-like receptor 9 (TLR9). RT-PCR and immunohistochemical or Western blot analyses were used to detect TLR9 mRNA and protein respectively in the lumbar (L4-L5) and cervical (C7-C8) dorsal root ganglia (DRG) ipsilateral and contralateral to a sterile unilateral sciatic nerve compression or transection. The unilateral sciatic nerve lesions led to bilateral increases in levels of both TLR9 mRNA and protein not only in the lumbar but also in the remote cervical DRG compared with naive or sham-operated controls. This upregulation of TLR9 was linked to activation of the Nuclear Factor kappa B (NFκB) and nuclear translocation of the Signal Transducer and Activator of Transcription 3 (STAT3), implying innate neuronal immune reaction and a pro-regenerative state in uninjured primary sensory neurons of the cervical DRG. The relationship of TLR9 to the induction of a pro-regenerative state in the cervical DRG neurons was confirmed by the shorter lengths of regenerated axons distal to ulnar nerve crush following a previous sciatic nerve lesion and intrathecal chloroquine injection compared with control rats. The results suggest that a systemic innate immune reaction not only triggers the regenerative state of axotomized DRG neurons but also induces a pro-regenerative state further along the neural axis after unilateral nerve injury.
Collapse
|
24
|
Uhelski ML, Li Y, Fonseca MM, Romero-Snadoval EA, Dougherty PM. Role of innate immunity in chemotherapy-induced peripheral neuropathy. Neurosci Lett 2021; 755:135941. [PMID: 33961945 DOI: 10.1016/j.neulet.2021.135941] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 04/28/2021] [Accepted: 04/30/2021] [Indexed: 01/18/2023]
Abstract
It has become increasingly clear that the innate immune system plays an essential role in the generation of many types of neuropathic pain including that which accompanies cancer treatment. In this article we review current findings of the role of the innate immune system in contributing to cancer treatment pain at the distal endings of peripheral nerve, in the nerve trunk, in the dorsal root ganglion and in the spinal dorsal horn.
Collapse
Affiliation(s)
- Megan L Uhelski
- The Department of Pain Medicine Research, The Division of Anesthesiology, Critical Care and Pain Medicine, The University of Texas M.D. Anderson Cancer Center, United States
| | - Yan Li
- The Department of Pain Medicine Research, The Division of Anesthesiology, Critical Care and Pain Medicine, The University of Texas M.D. Anderson Cancer Center, United States
| | - Miriam M Fonseca
- The Department of Anesthesiology, Wake Forest School of Medicine, United States
| | | | - Patrick M Dougherty
- The Department of Pain Medicine Research, The Division of Anesthesiology, Critical Care and Pain Medicine, The University of Texas M.D. Anderson Cancer Center, United States.
| |
Collapse
|
25
|
Fakhri S, Abbaszadeh F, Jorjani M. On the therapeutic targets and pharmacological treatments for pain relief following spinal cord injury: A mechanistic review. Biomed Pharmacother 2021; 139:111563. [PMID: 33873146 DOI: 10.1016/j.biopha.2021.111563] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Revised: 03/29/2021] [Accepted: 03/31/2021] [Indexed: 12/11/2022] Open
Abstract
Spinal cord injury (SCI) is globally considered as one of the most debilitating disorders, which interferes with daily activities and life of the affected patients. Despite many developments in related recognizing and treating procedures, post-SCI neuropathic pain (NP) is still a clinical challenge for clinicians with no distinct treatments. Accordingly, a comprehensive search was conducted in PubMed, Medline, Scopus, Web of Science, and national database (SID and Irandoc). The relevant articles regarding signaling pathways, therapeutic targets and pharmacotherapy of post-SCI pain were also reviewed. Data were collected with no time limitation until November 2020. The present study provides the findings on molecular mechanisms and therapeutic targets, as well as developing the critical signaling pathways to introduce novel neuroprotective treatments of post-SCI pain. From the pathophysiological mechanistic point of view, post-SCI inflammation activates the innate immune system, in which the immune cells elicit secondary injuries. So, targeting the critical signaling pathways for pain management in the SCI population has significant importance in providing new treatments. Indeed, several receptors, ion channels, excitatory neurotransmitters, enzymes, and key signaling pathways could be used as therapeutic targets, with a pivotal role of n-methyl-D-aspartate, gamma-aminobutyric acid, and inflammatory mediators. The current review focuses on conventional therapies, as well as crucial signaling pathways and promising therapeutic targets for post-SCI pain to provide new insights into the clinical treatment of post-SCI pain. The need to develop innovative delivery systems to treat SCI is also considered.
Collapse
Affiliation(s)
- Sajad Fakhri
- Pharmaceutical Sciences Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Fatemeh Abbaszadeh
- Neurobiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Department of Neuroscience, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences (IUMS), Tehran, Iran
| | - Masoumeh Jorjani
- Neurobiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Department of Pharmacology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| |
Collapse
|
26
|
Huang J, Gadotti VM, Zhang Z, Zamponi GW. The IL33 receptor ST2 contributes to mechanical hypersensitivity in mice with neuropathic pain. Mol Brain 2021; 14:35. [PMID: 33596932 PMCID: PMC7888111 DOI: 10.1186/s13041-021-00752-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 02/11/2021] [Indexed: 12/24/2022] Open
Abstract
Pathogen infection triggers pain via activation of the innate immune system. Toll-like receptors (TLRs) and Nod-like receptors (NLRs) are the main components of innate immunity and have been implicated in pain signaling. We previously revealed that the TLR2-NLRP3-IL33 pathway mediates inflammatory pain responses during hyperactivity of innate immunity. However, their roles in neuropathic pain had remained unclear. Here we report that although knockout of TLR2 or NLRP3 does not affect spared nerve injury (SNI)-induced neuropathic pain, intrathecal inhibition of IL33/ST2 signaling with ST2 neutralizing antibodies reverses mechanical thresholds in SNI mice compared to PBS vehicle treated animals. This effect indicates a universal role of IL33 in both inflammatory and neuropathic pain states, and that targeting the IL33/ST2 axis could be a potential therapeutic approach for pain treatment.
Collapse
Affiliation(s)
- Junting Huang
- Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, Guangdong, China. .,Department of Physiology and Pharmacology, Cumming School of Medicine, Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada.
| | - Vinicius M Gadotti
- Department of Physiology and Pharmacology, Cumming School of Medicine, Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Zizhen Zhang
- Department of Physiology and Pharmacology, Cumming School of Medicine, Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Gerald W Zamponi
- Department of Physiology and Pharmacology, Cumming School of Medicine, Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| |
Collapse
|
27
|
Livshits G, Kalinkovich A. Specialized, pro-resolving mediators as potential therapeutic agents for alleviating fibromyalgia symptomatology. PAIN MEDICINE 2021; 23:977-990. [PMID: 33565588 DOI: 10.1093/pm/pnab060] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVE To present a hypothesis on a novel strategy in the treatment of fibromyalgia (FM). DESIGN A narrative review. SETTING FM as a disease remains a challenging concept for numerous reasons, including undefined etiopathogenesis, unclear triggers and unsuccessful treatment modalities. We hypothesize that the inflammatome, the entire set of molecules involved in inflammation, acting as a common pathophysiological instrument of gut dysbiosis, sarcopenia, and neuroinflammation, is one of the major mechanisms underlying FM pathogenesis. In this setup, dysbiosis is proposed as the primary trigger of the inflammatome, sarcopenia as the peripheral nociceptive source, and neuroinflammation as the central mechanism of pain sensitization, transmission and symptomatology of FM. Whereas neuroinflammation is highly-considered as a critical deleterious element in FM pathogenesis, the presumed pathogenic roles of sarcopenia and systemic inflammation remain controversial. Nevertheless, sarcopenia-associated processes and dysbiosis have been recently detected in FM individuals. The prevalence of pro-inflammatory factors in the cerebrospinal fluid and blood has been repeatedly observed in FM individuals, supporting an idea on the role of inflammatome in FM pathogenesis. As such, failed inflammation resolution might be one of the underlying pathogenic mechanisms. In accordance, the application of specialized, inflammation pro-resolving mediators (SPMs) seems most suitable for this goal. CONCLUSIONS The capability of various SPMs to prevent and attenuate pain has been repeatedly demonstrated in laboratory animal experiments. Since SPMs suppress inflammation in a manner that does not compromise host defense, they could be attractive and safe candidates for the alleviation of FM symptomatology, probably in combination with anti-dysbiotic medicine.
Collapse
Affiliation(s)
- Gregory Livshits
- Adelson School of Medicine, Ariel University, Ariel, Israel.,Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Alexander Kalinkovich
- Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| |
Collapse
|
28
|
Lagomarsino VN, Kostic AD, Chiu IM. Mechanisms of microbial-neuronal interactions in pain and nociception. NEUROBIOLOGY OF PAIN 2020; 9:100056. [PMID: 33392418 PMCID: PMC7772816 DOI: 10.1016/j.ynpai.2020.100056] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 11/18/2020] [Accepted: 11/27/2020] [Indexed: 02/06/2023]
Abstract
Molecular mechanisms of how microorganisms communicate with sensory afferent neurons. How pathogenic microorganisms directly communicate with nociceptor neurons to inflict pain on the host. Symbiotic bacterial communication with gut-extrinsic sensory afferent neurons. Plausible roles on how gut symbionts directly mediate pain and nociception.
Nociceptor sensory neurons innervate barrier tissues that are constantly exposed to microbial stimuli. During infection, pathogenic microorganisms can breach barrier surfaces and produce pain by directly activating nociceptors. Microorganisms that live in symbiotic relationships with their hosts, commensals and mutualists, have also been associated with pain, but the molecular mechanisms of how symbionts act on nociceptor neurons to modulate pain remain largely unknown. In this review, we will discuss the known molecular mechanisms of how microbes directly interact with sensory afferent neurons affecting nociception in the gut, skin and lungs. We will touch on how bacterial, viral and fungal pathogens signal to the host to inflict or suppress pain. We will also discuss recent studies examining how gut symbionts affect pain. Specifically, we will discuss how gut symbionts may interact with sensory afferent neurons either directly, through secretion of metabolites or neurotransmitters, or indirectly,through first signaling to epithelial cells or immune cells, to regulate visceral, neuropathic and inflammatory pain. While this area of research is still in its infancy, more mechanistic studies to examine microbial-sensory neuron crosstalk in nociception may allow us to develop new therapies for the treatment of acute and chronic pain.
Collapse
Affiliation(s)
- Valentina N Lagomarsino
- Department of Immunology, Harvard Medical School, Boston, MA 02115, USA.,Joslin Diabetes Center, Boston, MA 02115, USA.,Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA
| | - Aleksandar D Kostic
- Joslin Diabetes Center, Boston, MA 02115, USA.,Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA
| | - Isaac M Chiu
- Department of Immunology, Harvard Medical School, Boston, MA 02115, USA
| |
Collapse
|
29
|
Abstract
The gut-brain axis is a coordinated communication system that not only maintains homeostasis, but significantly influences higher cognitive functions and emotions, as well as neurological and behavioral disorders. Among the large populations of sensory and motor neurons that innervate the gut, insights into the function of primary afferent nociceptors, whose cell bodies reside in the dorsal root ganglia and nodose ganglia, have revealed their multiple crosstalk with several cell types within the gut wall, including epithelial, vascular, and immune cells. These bidirectional communications have immunoregulatory functions, control host response to pathogens, and modulate sensations associated with gastrointestinal disorders, through activation of immune cells and glia in the peripheral and central nervous system, respectively. Here, we will review the cellular and neurochemical basis of these interactions at the periphery, in dorsal root ganglia, and in the spinal cord. We will discuss the research gaps that should be addressed to get a better understanding of the multifunctional role of sensory neurons in maintaining gut homeostasis and regulating visceral sensitivity.
Collapse
Affiliation(s)
- Nasser Abdullah
- Department of Physiology and Pharmacology, Inflammation Research Network-Snyder Institute for Chronic Diseases and Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
| | - Manon Defaye
- Department of Physiology and Pharmacology, Inflammation Research Network-Snyder Institute for Chronic Diseases and Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
| | - Christophe Altier
- Department of Physiology and Pharmacology, Inflammation Research Network-Snyder Institute for Chronic Diseases and Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
| |
Collapse
|
30
|
The Role of the Microbiome and Microbiome-Derived Metabolites in Atopic Dermatitis and Non-Histaminergic Itch. Am J Clin Dermatol 2020; 21:44-50. [PMID: 32910440 PMCID: PMC7584541 DOI: 10.1007/s40257-020-00538-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Recent advances in our understanding of the pathophysiology of atopic dermatitis (AD) have revealed that skin microbiome dysbiosis plays an important role in the disease. In this review, we describe how changes in the structure and function of the microbiome are involved in the pathogenesis of AD. We highlight recent data showing that differential changes in microbial diversity, both within and across communities from different body habitats (including the skin, gut, and oral mucosa), are associated with the development and severity of AD. We also describe recent evidence demonstrating that the metabolic activity of the skin microbiome can act as a regulator of inflammation, with alterations in the level of a skin microbiome-derived tryptophan metabolite, indole-3-aldehyde (IAId), being shown to play a role in AD. The various mechanisms by which interactions between the microbiome and components of the non-histaminergic pathway result in itch in AD are also discussed.
Collapse
|
31
|
Donnelly CR, Chen O, Ji RR. How Do Sensory Neurons Sense Danger Signals? Trends Neurosci 2020; 43:822-838. [PMID: 32839001 DOI: 10.1016/j.tins.2020.07.008] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 07/11/2020] [Accepted: 07/27/2020] [Indexed: 12/27/2022]
Abstract
Sensory neurons are activated by physical and chemical stimuli, eliciting sensations such as temperature, touch, pain, and itch. From an evolutionary perspective, sensing danger is essential for organismal survival. Upon infection and injury, immune cells respond to pathogen/damage-associated molecular patterns (PAMPs/DAMPs) through pattern recognition receptors (PRRs) such as Toll-like receptors (TLRs), and produce inflammatory mediators that activate sensory neurons through neuro-immune interactions. Sensory neurons also express TLRs and other PRRs that directly sense danger signals after injury or during infection, leading to pain, itch, or analgesia. In addition to slow-acting canonical TLR signaling, TLRs function uniquely in sensory neurons through non-canonical coupling to ion channels, enabling rapid modulation of neuronal activity. We discuss how sensory neurons utilize TLRs and other PRR pathways to detect danger signals in their environment.
Collapse
Affiliation(s)
- Christopher R Donnelly
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Ouyang Chen
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA; Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Ru-Rong Ji
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA; Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA; Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA.
| |
Collapse
|
32
|
Ramirez V, Swain S, Murray K, Reardon C. Neural Immune Communication in the Control of Host-Bacterial Pathogen Interactions in the Gastrointestinal Tract. Infect Immun 2020; 88:e00928-19. [PMID: 32341116 PMCID: PMC7440759 DOI: 10.1128/iai.00928-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The orchestration of host immune responses to enteric bacterial pathogens is a complex process involving the integration of numerous signals, including from the nervous system. Despite the recent progress in understanding the contribution of neuroimmune interactions in the regulation of inflammation, the mechanisms and effects of this communication during enteric bacterial infection are only beginning to be characterized. As part of this neuroimmune communication, neurons specialized to detect painful or otherwise noxious stimuli can respond to bacterial pathogens. Highlighting the complexity of these systems, the immunological consequences of sensory neuron activation can be either host adaptive or maladaptive, depending on the pathogen and organ system. These are but one of many types of neuroimmune circuits, with the vagus nerve and sympathetic innervation of numerous organs now known to modulate immune cell function and therefore dictate immunological outcomes during health and disease. Here, we review the evidence for neuroimmune communication in response to bacterial pathogens, and then discuss the consequences to host morbidity and mortality during infection of the gastrointestinal tract.
Collapse
Affiliation(s)
- Valerie Ramirez
- Department. of Anatomy, Physiology, and Cell Biology, UC Davis School of Veterinary Medicine, Davis, California, USA
| | - Samantha Swain
- Department. of Anatomy, Physiology, and Cell Biology, UC Davis School of Veterinary Medicine, Davis, California, USA
| | - Kaitlin Murray
- Department. of Anatomy, Physiology, and Cell Biology, UC Davis School of Veterinary Medicine, Davis, California, USA
| | - Colin Reardon
- Department. of Anatomy, Physiology, and Cell Biology, UC Davis School of Veterinary Medicine, Davis, California, USA
| |
Collapse
|
33
|
Cohen JA, Wu J, Kaplan DH. Neuronal Regulation of Cutaneous Immunity. THE JOURNAL OF IMMUNOLOGY 2020; 204:264-270. [PMID: 31907268 DOI: 10.4049/jimmunol.1901109] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 11/05/2019] [Indexed: 12/11/2022]
Abstract
The skin is innervated by numerous sensory afferent neurons that respond to a diverse array of stimuli ranging from gentle touch to noxious pain. Various features of the immune system-pathogen recognition, secretion of soluble mediators-are shared with the nervous system. This has led to the recognition that neurons share some functions with innate immune cells and have the capacity to recognize pathogens and participate in innate immune responses. Neuroimmune interactions are bidirectional. Soluble mediators from immune cells activate neurons and soluble mediators from neurons can activate immune cells. In this review, we will focus on the interplay between neurons and innate immunity in the skin in the context of host defense and inflammation.
Collapse
Affiliation(s)
- Jonathan A Cohen
- Departments of Dermatology and Immunology, University of Pittsburgh, Pittsburgh, PA 15261
| | - Jianing Wu
- Departments of Dermatology and Immunology, University of Pittsburgh, Pittsburgh, PA 15261.,School of Medicine, Tsinghua University, Haidian District, Beijing 100084, China; and
| | - Daniel H Kaplan
- Departments of Dermatology and Immunology, University of Pittsburgh, Pittsburgh, PA 15261; .,Pittsburgh Center for Pain Research, University of Pittsburgh, Pittsburgh, PA 15261
| |
Collapse
|
34
|
Toll-like receptor 7 contributes to neuropathic pain by activating NF-κB in primary sensory neurons. Brain Behav Immun 2020; 87:840-851. [PMID: 32205121 PMCID: PMC7316623 DOI: 10.1016/j.bbi.2020.03.019] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 03/17/2020] [Accepted: 03/19/2020] [Indexed: 01/01/2023] Open
Abstract
Toll like receptor 7 (TLR7) is expressed in neurons of the dorsal root ganglion (DRG), but whether it contributes to neuropathic pain is elusive. We found that peripheral nerve injury caused by ligation of the fourth lumbar (L4) spinal nerve (SNL) or chronic constriction injury of sciatic nerve led to a significant increase in the expression of TLR7 at mRNA and protein levels in mouse injured DRG. Blocking this increase through microinjection of the adeno-associated virus (AAV) 5 expressing TLR7 shRNA into the ipsilateral L4 DRG alleviated the SNL-induced mechanical, thermal and cold pain hypersensitivities in both male and female mice. This microinjection also attenuated the SNL-induced increases in the levels of phosphorylated extracellular signal-regulated kinase ½ (p-ERK1/2) and glial fibrillary acidic protein (GFAP) in L4 dorsal horn on the ipsilateral side during both development and maintenance periods. Conversely, mimicking this increase through microinjection of AAV5 expressing full-length TLR7 into unilateral L3/4 DRGs led to elevations in the amounts of p-ERK1/2 and GFAP in the dorsal horn, augmented responses to mechanical, thermal and cold stimuli, and induced the spontaneous pain on the ipsilateral side in the absence of SNL. Mechanistically, the increased TLR7 activated the NF-κB signaling pathway through promoting the translocation of p65 into the nucleus and phosphorylation of p65 in the nucleus from the injured DRG neurons. Our findings suggest that DRG TLR7 contributes to neuropathic pain by activating NF-κB in primary sensory neurons. TLR7 may be a potential target for therapeutic treatment of this disorder.
Collapse
|
35
|
Abstract
A limited number of peripheral targets generate pain. Inflammatory mediators can sensitize these. The review addresses targets acting exclusively or predominantly on sensory neurons, mediators involved in inflammation targeting sensory neurons, and mediators involved in a more general inflammatory process, of which an analgesic effect secondary to an anti-inflammatory effect can be expected. Different approaches to address these systems are discussed, including scavenging proinflammatory mediators, applying anti-inflammatory mediators, and inhibiting proinflammatory or facilitating anti-inflammatory receptors. New approaches are contrasted to established ones; the current stage of progress is mentioned, in particular considering whether there is data from a molecular and cellular level, from animals, or from human trials, including an early stage after a market release. An overview of publication activity is presented, considering a IuPhar/BPS-curated list of targets with restriction to pain-related publications, which was also used to identify topics.
Collapse
Affiliation(s)
- Cosmin I Ciotu
- Center of Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse 17, 1090, Vienna, Austria
| | - Michael J M Fischer
- Center of Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse 17, 1090, Vienna, Austria.
| |
Collapse
|
36
|
Carnevale D, Lembo G. Neuroimmune interactions in cardiovascular diseases. Cardiovasc Res 2020; 117:402-410. [PMID: 32462184 DOI: 10.1093/cvr/cvaa151] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 04/27/2020] [Accepted: 05/22/2020] [Indexed: 02/07/2023] Open
Abstract
Our body is continuously in contact with external stimuli that need a fine integration with the internal milieu in order to maintain the homoeostasis. Similarly, perturbations of the internal environment are responsible for the alterations of the physiological mechanisms regulating our main functions. The nervous system and the immune system represent the main interfaces between the internal and the external environment. In carrying out these functions, they share many similarities, being able to recognize, integrate, and organize responses to a wide variety of stimuli, with the final aim to re-establish the homoeostasis. The autonomic nervous system, which collectively refers to the ensemble of afferent and efferent neurons that wire the central nervous system with visceral effectors throughout the body, is the prototype system controlling the homoeostasis through reflex arches. On the other hand, immune cells continuously patrol our body against external enemies and internal perturbations, organizing acute responses and forming memory for future encounters. Interesting to notice, the integration of the two systems provides a further unique opportunity for fine tuning of our body's homoeostasis. In fact, the autonomic nervous system guides the development of lymphoid and myeloid organs, as well as the deployment of immune cells towards peripheral tissues where they can affect and control several physiological functions. In turn, every specific immune cell type can contribute to regulate neural circuits involved in cardiovascular function, metabolism, and inflammation. Here, we review current understanding of the cross-regulation between these systems in cardiovascular diseases.
Collapse
Affiliation(s)
- Daniela Carnevale
- Department of Angiocardioneurology and Translational Medicine, IRCCS Neuromed, Via dell'Elettronica, 86077 Pozzilli IS, Italy.,Department of Molecular Medicine, Sapienza University of Rome, Viale Regina Elena 291, 00161 Rome, Italy
| | - Giuseppe Lembo
- Department of Angiocardioneurology and Translational Medicine, IRCCS Neuromed, Via dell'Elettronica, 86077 Pozzilli IS, Italy.,Department of Molecular Medicine, Sapienza University of Rome, Viale Regina Elena 291, 00161 Rome, Italy
| |
Collapse
|
37
|
Arnaboldi F, Sommariva M, Opizzi E, Rasile M, Camelliti S, Busnelli M, Menegola E, Di Renzo F, Menon A, Barajon I. Expression of Toll-like receptors 4 and 7 in murine peripheral nervous system development. Ann Anat 2020; 231:151526. [PMID: 32380196 DOI: 10.1016/j.aanat.2020.151526] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 02/03/2020] [Accepted: 04/10/2020] [Indexed: 12/18/2022]
Abstract
BACKGROUND Toll-Like Receptors (TLRs) play a critical role in the innate and adaptive immune system. They are the mammalian orthologs of Drosophila melanogaster protein Toll, which has been proved to have an early morphogenetic role in invertebrate embryogenesis that in the adult switches to an immune function. AIM The aim of this study was to evaluate the expression of TLR4 and TLR7 during dorsal root ganglia (DRG), paravertebral ganglia (PVG), and enteric nervous system (ENS) murine development. METHODS Mouse embryos from different stages (i.e. E12 to E18) were processed for immunolocalization analysis on formalin-fixed paraffin-embedded sections, and isolated intestine were processed for whole-mount preparations. RESULTS We observed a differentially regulated expression of TLR4 and TLR7 during embryogenesis and an overall increased expression of both receptors during development. While TLR4 was detectable in neurons of DRG and PVG starting from E14 and only from E18 in the ENS, TLR7 was already expressed in scattered neurons of all the investigated regions at E12. CONCLUSIONS TLR4 and TRL7 expression temporal patterns suggest a morphogenetic role for these receptors in the development of neural crest derivatives in mammals.
Collapse
Affiliation(s)
- Francesca Arnaboldi
- Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Via Mangiagalli 31, 20133 Milano, Italy.
| | - Michele Sommariva
- Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Via Mangiagalli 31, 20133 Milano, Italy
| | - Emanuela Opizzi
- Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Via Mangiagalli 31, 20133 Milano, Italy
| | - Marco Rasile
- Humanitas Clinical and Research Center, Via Manzoni 56, 20089 Rozzano, Milano, Italy; Humanitas University, Via Rita Levi Montalcini 4, 20090 Pieve Emanuele, Milano, Italy
| | - Simone Camelliti
- Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Via Mangiagalli 31, 20133 Milano, Italy
| | - Marco Busnelli
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Via Balzaretti, 9/11/13, 20133 Milano, Italy
| | - Elena Menegola
- Dipartimento di Scienze e Politiche Ambientali, Università degli Studi di Milano, Via Celoria 26, 20133 Milano, Italy
| | - Francesca Di Renzo
- Dipartimento di Scienze e Politiche Ambientali, Università degli Studi di Milano, Via Celoria 26, 20133 Milano, Italy
| | - Alessandra Menon
- Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Via Mangiagalli 31, 20133 Milano, Italy; Clinica Ortopedica, ASST Centro Specialistico Ortopedico Traumatologico Gaetano Pini-CTO, Milan, Italy
| | - Isabella Barajon
- Humanitas University, Via Rita Levi Montalcini 4, 20090 Pieve Emanuele, Milano, Italy
| |
Collapse
|
38
|
Miller RJ, Malfait AM, Miller RE. The innate immune response as a mediator of osteoarthritis pain. Osteoarthritis Cartilage 2020; 28:562-571. [PMID: 31862470 PMCID: PMC6951330 DOI: 10.1016/j.joca.2019.11.006] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 11/20/2019] [Indexed: 02/08/2023]
Abstract
In this narrative review, we discuss the emerging role of innate immunity in osteoarthritis (OA) joint pain. First, we give a brief description of the pain pathway in the context of OA. Then we consider how neuro-immune signaling pathways may promote OA pain. First, activation of neuronal Pattern Recognition Receptors by mediators released in a damaged joint can result in direct excitation of nociceptors, as well as in production of chemokines and cytokines. Secondly, indirect neuro-immune signaling may occur when innate immune cells produce algogenic factors, including chemokines and cytokines, that act on the pain pathway. Neuro-immune crosstalk occurs at different levels of the pathway, starting in the joint but also in the innervating dorsal root ganglia and in the dorsal horn. Synovitis is characterized by recruitment of immune cells, including macrophages, mast cells, and CD4+ lymphocytes, which may contribute to nociceptor sensitization and OA pain through production of algogenic factors that amplify the activation of sensory neurons. We discuss examples where this scenario has been suggested by findings in human OA and in animal models. Overall, increasing evidence suggests that innate immune pathways play an initiating as well as facilitating role in pain, but information on how these pathways operate in OA remains limited. Since these innate pathways are eminently targetable, future studies in this area may provide fruitful leads towards a better management of symptomatic OA.
Collapse
|
39
|
Kaewpitak A, Bauer CS, Seward EP, Boissonade FM, Douglas CWI. Porphyromonas gingivalis
lipopolysaccharide rapidly activates trigeminal sensory neurons and may contribute to pulpal pain. Int Endod J 2020; 53:846-858. [DOI: 10.1111/iej.13282] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Accepted: 02/12/2020] [Indexed: 01/19/2023]
Affiliation(s)
- A. Kaewpitak
- School of Clinical Dentistry University of Sheffield Sheffield UK
| | - C. S. Bauer
- Department of Biomedical Science University of Sheffield Sheffield UK
| | - E. P. Seward
- Department of Biomedical Science University of Sheffield Sheffield UK
| | - F. M. Boissonade
- School of Clinical Dentistry University of Sheffield Sheffield UK
| | - C. W. I. Douglas
- School of Clinical Dentistry University of Sheffield Sheffield UK
| |
Collapse
|
40
|
Wang TT, Xu XY, Lin W, Hu DD, Shi W, Jia X, Wang H, Song NJ, Zhang YQ, Zhang L. Activation of Different Heterodimers of TLR2 Distinctly Mediates Pain and Itch. Neuroscience 2020; 429:245-255. [DOI: 10.1016/j.neuroscience.2020.01.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 01/03/2020] [Accepted: 01/07/2020] [Indexed: 10/25/2022]
|
41
|
Li G, Forero MG, Wentzell JS, Durmus I, Wolf R, Anthoney NC, Parker M, Jiang R, Hasenauer J, Strausfeld NJ, Heisenberg M, Hidalgo A. A Toll-receptor map underlies structural brain plasticity. eLife 2020; 9:52743. [PMID: 32066523 PMCID: PMC7077983 DOI: 10.7554/elife.52743] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 02/12/2020] [Indexed: 12/28/2022] Open
Abstract
Experience alters brain structure, but the underlying mechanism remained unknown. Structural plasticity reveals that brain function is encoded in generative changes to cells that compete with destructive processes driving neurodegeneration. At an adult critical period, experience increases fiber number and brain size in Drosophila. Here, we asked if Toll receptors are involved. Tolls demarcate a map of brain anatomical domains. Focusing on Toll-2, loss of function caused apoptosis, neurite atrophy and impaired behaviour. Toll-2 gain of function and neuronal activity at the critical period increased cell number. Toll-2 induced cycling of adult progenitor cells via a novel pathway, that antagonized MyD88-dependent quiescence, and engaged Weckle and Yorkie downstream. Constant knock-down of multiple Tolls synergistically reduced brain size. Conditional over-expression of Toll-2 and wek at the adult critical period increased brain size. Through their topographic distribution, Toll receptors regulate neuronal number and brain size, modulating structural plasticity in the adult brain. Everything that you experience leaves its mark on your brain. When you learn something new, the neurons involved in the learning episode grow new projections and form new connections. Your brain may even produce new neurons. Physical exercise can induce similar changes, as can taking antidepressants. By contrast, stress, depression, ageing and disease can have the opposite effect, triggering neurons to break down and even die. The ability of the brain to change in response to experience is known as structural plasticity, and it is in a tug-of-war with processes that drive neurodegeneration. Structural plasticity occurs in other species too: for example, it was described in the fruit fly more than a quarter of a century ago. Yet, the molecular mechanisms underlying structural plasticity remain unclear. Li et al. now show that, in fruit flies, this plasticity involves Toll receptors, a family of proteins present in the brain but best known for their role in the immune system. Fruit flies have nine different Toll receptors, the most abundant being Toll-2. When activated, these proteins can trigger a series of molecular events in a cell. Li et al. show that increasing the amount of Toll-2 in the fly brain makes the brain produce new neurons. Activating neurons in a brain region has the same effect, and this increase in neuron number also depends on Toll-2. By contrast, reducing the amount of Toll-2 causes neurons to lose their projections and connections, and to die, and impairs fly behaviour. Li et al. also show that each Toll receptor has a unique distribution across the fly brain. Different types of experiences activate different brain regions, and therefore different Toll receptors. These go on to trigger a common molecular cascade, but they modulate it such as to result in distinct outcomes. By working together in different combinations, Toll receptors can promote either the death or survival of neurons, and they can also drive specific brain cells to remain dormant or to produce new neurons. By revealing how experience changes the brain, Li et al. provide clues to the way neurons work and form; these findings may also help to find new treatments for disorders that change brain structure, such as certain psychiatric conditions. Toll-like receptors in humans could thus represent a promising new target for drug discovery.
Collapse
Affiliation(s)
- Guiyi Li
- Neurodevelopment Lab, School of Biosciences, University of Birmingham, Birmingham, United Kingdom.,Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
| | - Manuel G Forero
- Facultad de Ingeniería, Universidad de Ibagué, Ibagué, Colombia
| | - Jill S Wentzell
- Neurodevelopment Lab, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Ilgim Durmus
- Neurodevelopment Lab, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Reinhard Wolf
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
| | - Niki C Anthoney
- Neurodevelopment Lab, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Mieczyslaw Parker
- Neurodevelopment Lab, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Ruiying Jiang
- Neurodevelopment Lab, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Jacob Hasenauer
- Neurodevelopment Lab, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Nicholas James Strausfeld
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany.,Neuroscience, University of Arizona College of Science, Tucson, United States
| | - Martin Heisenberg
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
| | - Alicia Hidalgo
- Neurodevelopment Lab, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| |
Collapse
|
42
|
Dworsky-Fried Z, Kerr BJ, Taylor AMW. Microbes, microglia, and pain. NEUROBIOLOGY OF PAIN 2020; 7:100045. [PMID: 32072077 PMCID: PMC7016021 DOI: 10.1016/j.ynpai.2020.100045] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 01/23/2020] [Accepted: 01/24/2020] [Indexed: 02/08/2023]
Abstract
Explore the connection between the gut microbiome and microglia in chronic pain. Discuss mechanisms by which gut bacteria might influence microglia to contribute to chronic pain. Highlight gaps in knowledge and discuss future directions for the field.
Globally, it is estimated that one in five people suffer from chronic pain, with prevalence increasing with age. The pathophysiology of chronic pain encompasses complex sensory, immune, and inflammatory interactions within both the central and peripheral nervous systems. Microglia, the resident macrophages of the central nervous system (CNS), are critically involved in the initiation and persistence of chronic pain. Microglia respond to local signals from the CNS but are also modulated by signals from the gastrointestinal tract. Emerging data from preclinical and clinical studies suggest that communication between the gut microbiome, the community of bacteria residing within the gut, and microglia is involved in producing chronic pain. Targeted strategies that manipulate or restore the gut microbiome have been shown to reduce microglial activation and alleviate symptoms associated with inflammation. These data indicate that manipulations of the gut microbiome in chronic pain patients might be a viable strategy in improving pain outcomes. Herein, we discuss the evidence for a connection between microglia and the gut microbiome and explore the mechanisms by which commensal bacteria might influence microglial reactivity to drive chronic pain.
Collapse
Affiliation(s)
- Zoë Dworsky-Fried
- Department of Pharmacology, University of Alberta, Edmonton T6G2H7, Canada
| | - Bradley J Kerr
- Department of Pharmacology, University of Alberta, Edmonton T6G2H7, Canada.,Neuroscience and Mental Health Institute, University of Alberta, Edmonton T6G2H7, Canada.,Department of Anesthesiology and Pain Medicine, University of Alberta, Edmonton T6G2H7, Canada
| | - Anna M W Taylor
- Department of Pharmacology, University of Alberta, Edmonton T6G2H7, Canada.,Neuroscience and Mental Health Institute, University of Alberta, Edmonton T6G2H7, Canada.,Department of Anesthesiology and Pain Medicine, University of Alberta, Edmonton T6G2H7, Canada
| |
Collapse
|
43
|
DeMarco GJ, Nunamaker EA. A Review of the Effects of Pain and Analgesia on Immune System Function and Inflammation: Relevance for Preclinical Studies. Comp Med 2019; 69:520-534. [PMID: 31896389 PMCID: PMC6935697 DOI: 10.30802/aalas-cm-19-000041] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
One of the most significant challenges facing investigators, laboratory animal veterinarians, and IACUCs, is how to balance appropriate analgesic use, animal welfare, and analgesic impact on experimental results. This is particularly true for in vivo studies on immune system function and inflammatory disease. Often times the effects of analgesic drugs on a particular immune function or model are incomplete or don't exist. Further complicating the picture is evidence of the very tight integration and bidirectional functionality between the immune system and branches of the nervous system involved in nociception and pain. These relationships have advanced the concept of understanding pain as a protective neuroimmune function and recognizing pathologic pain as a neuroimmune disease. This review strives to summarize extant literature on the effects of pain and analgesia on immune system function and inflammation in the context of preclinical in vivo studies. The authors hope this work will help to guide selection of analgesics for preclinical studies of inflammatory disease and immune system function.
Collapse
Key Words
- cb,endocannabinoid receptor
- cd,crohn disease
- cfa, complete freund adjuvant
- cgrp,calcitonin gene-related peptide
- cox,cyclooxygenase
- ctl, cytotoxic t-lymphocytes
- damp,damage-associated molecular pattern molecules
- drg,dorsal root ganglion
- dss, dextran sodium sulphate
- ecs,endocannabinoid system
- ibd, inflammatory bowel disease
- ifa,incomplete freund adjuvant
- las, local anesthetics
- pamp,pathogen-associated molecular pattern molecules
- pge2, prostaglandin e2
- p2y, atp purine receptor y
- p2x, atp purine receptor x
- tnbs, 2,4,6-trinitrobenzene sulphonic acid
- trp, transient receptor potential ion channels
- trpv, transient receptor potential vanilloid
- tg,trigeminal ganglion
- uc,ulcerative colitis
Collapse
Affiliation(s)
- George J DeMarco
- Department of Animal Medicine, University of Massachusetts Medical School, Worcester, Massachusetts;,
| | | |
Collapse
|
44
|
Liu F, Chen Y, Liu R, Chen B, Liu C, Xing J. Long noncoding RNA (MEG3) in urinal exosomes functions as a biomarker for the diagnosis of Hunner-type interstitial cystitis (HIC). J Cell Biochem 2019; 121:1227-1237. [PMID: 31595563 DOI: 10.1002/jcb.29356] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 03/22/2019] [Indexed: 01/01/2023]
Abstract
BACKGROUND Toll-like receptor-7 (TLR7) is functionally involved in the pathogenesis of Hunner-type interstitial cystitis (HIC). In addition, maternally expressed gene 3 (MEG3) is implicated in many urethral diseases. In this study, we aimed to verify the hypothesis that exosomal MEG3 in urine can be used as a novel diagnostic biomarker for HIC. METHODS Electron microscopy was utilized to observe the distribution of urinary exosomes between the case group and the control group. Receiver operating characteristic analysis was utilized to compare the diagnostic values of MEG3 and miR-19a-3p. Computational analysis and luciferase assay were conducted to identify the correlation between MEG3 and miR-19a-3p as well as between TLR7 and miR-19a-3p. In addition, real-time polymerase chain reaction and Western blot were performed to establish the signaling pathways implicated in the pathogenesis of HIC. RESULTS When age and gender distributions are excluded, urinary exosomes were equally distributed between case and control groups. The area under the curve of MEG3 was larger than that of miR-19a-3p, indicating that MEG3 has a better value in the diagnosis of HIC. In addition, patients with HIC showed elevated MEG3 expression and inhibited miR-19a-3p expression, thus establishing a negative correlation between MEG3 and miR-19a-3p. MEG3 and TLR7 were both identified as targets of miR-19a-3p, establishing a MEG3/miR-19a-3p/TLR7 signaling pathway, in which MEG3 enhances the expression of TLR7 via inhibiting the expression of miR-19a-3p. CONCLUSION MEG3 level was upregulated in patients with HIC. In addition, MEG3 downregulated miR-19a-3p expression while upregulating TLR7 expression. Furthermore, MEG3 contributes to the pathogenesis of HIC. Therefore, exosomal MEG3 in urine can be used as a biomarker for HIC diagnosis.
Collapse
Affiliation(s)
- Fei Liu
- Department of Urology, Zhujiang Hospital of Southern Medical University, Guangzhou, Guangdong, China.,Department of Urology, The First Affiliated Hospital of Xiamen University, Xiamen, Fujian, China
| | - Yuedong Chen
- Department of Urology, The First Affiliated Hospital of Xiamen University, Xiamen, Fujian, China
| | - Rongfu Liu
- Department of Urology, The First Affiliated Hospital of Xiamen University, Xiamen, Fujian, China
| | - Bin Chen
- Department of Urology, The First Affiliated Hospital of Xiamen University, Xiamen, Fujian, China
| | - Chunxiao Liu
- Department of Urology, Zhujiang Hospital of Southern Medical University, Guangzhou, Guangdong, China
| | - Jinchun Xing
- Department of Urology, The First Affiliated Hospital of Xiamen University, Xiamen, Fujian, China
| |
Collapse
|
45
|
Alves LCV, Lisboa MRP, da Silveira HF, de Sousa LM, Gusmão JNFM, Dias DBS, Ervolino E, Furlaneto FAC, Vale ML, Gondim DV. Electroacupuncture increases immunoexpression of CB1 and CB2 receptors in experimental model of inflammatory bone loss. Bone 2019; 127:59-66. [PMID: 31121356 DOI: 10.1016/j.bone.2019.05.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 05/05/2019] [Accepted: 05/12/2019] [Indexed: 11/22/2022]
Abstract
This study evaluated the participation of CB1 and CB2 receptors in the antiresorptive effect of electroacupuncture (EA) on an experimental model of inflammatory bone loss in rats. 30 rats were divided into five groups: C (control); EP (experimental periodontitis); EA (C+ EA); EP-EA (EP+ EA in the acupoints LI4, LG11, ST36, ST44); EP - EA-sham (EP+ EA in sham acupoints). For the EP groups, a ligature was placed around the right mandibular first molars at day 1. Sessions of EA or EA-sham were assigned every other day. Animals were euthanized at day 11. Histometric analysis was performed to evaluate the percentage of bone area in the furcation area. Immunolabeling patterns in the periodontal tissues and immunofluorescent staining in the trigeminal ganglia and in the trigeminal spinal tract for CB1 and CB2 receptors were performed. It was observed increased bone loss in the furcation in the EP and EP-EA-sham groups, in comparison to the other groups (p < 0.05). Enhanced CB2 immunolabeling was observed in the periodontal tissues in the EP-EA group, when compared to the EP and EP-EA-sham groups (p < 0.05). Increased CB1 immunofluorescent staining was observed in the neural tissues in the EA treated group in comparison with the other groups (p < 0.05), while no expression of CB2 was observed in those regions. Our study showed that in the presence of inflammatory bone disease, EA treatment reduced bone erosion and increased the immunoexpression of CB1 in the neural tissues and CB2 in the periodontal tissues.
Collapse
Affiliation(s)
- Luiza Clertiani Vieira Alves
- Department of Clinical Dentistry, Graduate Program in Dentistry, Faculty of Pharmacy, Dentistry and Nursing, Federal University of Ceará - UFC, Fortaleza, Ceará, Brazil
| | | | | | - Luane Macêdo de Sousa
- Department of Morphology, Faculty of Medicine, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | | | - Diego Bernarde Souza Dias
- Department of Nursing, Faculty of |Pharmacy, Dentistry and Nursing, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | - Edilson Ervolino
- Division of Histology, Department of Basic Sciences, Dental School of Araçatuba, São Paulo State University - UNESP, Araçatuba, SP, Brazil
| | - Flávia Aparecida Chaves Furlaneto
- Department of Oral & Maxillofacial Surgery and Periodontology, School of Dentistry of Ribeirao Preto, University of Sao Paulo - USP, Ribeirao Preto, SP, Brazil
| | - Mariana Lima Vale
- Department of Physiology and Pharmacology, Faculty of Medicine, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | - Delane Viana Gondim
- Department of Morphology, Faculty of Medicine, Federal University of Ceará, Fortaleza, Ceará, Brazil.
| |
Collapse
|
46
|
Microbiota: a novel regulator of pain. J Neural Transm (Vienna) 2019; 127:445-465. [PMID: 31552496 DOI: 10.1007/s00702-019-02083-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 09/16/2019] [Indexed: 02/07/2023]
Abstract
Among the various regulators of the nervous system, the gut microbiota has been recently described to have the potential to modulate neuronal cells activation. While bacteria-derived products can induce aversive responses and influence pain perception, recent work suggests that "abnormal" microbiota is associated with neurological diseases such as Alzheimer's, Parkinson's disease or autism spectrum disorder (ASD). Here we review how the gut microbiota modulates afferent sensory neurons function and pain, highlighting the role of the microbiota/gut/brain axis in the control of behaviors and neurological diseases. We outline the changes in gut microbiota, known as dysbiosis, and their influence on painful gastrointestinal disorders. Furthermore, both direct host/microbiota interaction that implicates activation of "pain-sensing" neurons by metabolites, or indirect communication via immune activation is discussed. Finally, treatment options targeting the gut microbiota, including pre- or probiotics, will be proposed. Further studies on microbiota/nervous system interaction should lead to the identification of novel microbial ligands and host receptor-targeted drugs, which could ultimately improve chronic pain management and well-being.
Collapse
|
47
|
Pain regulation by gut microbiota: molecular mechanisms and therapeutic potential. Br J Anaesth 2019; 123:637-654. [PMID: 31551115 DOI: 10.1016/j.bja.2019.07.026] [Citation(s) in RCA: 165] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 07/15/2019] [Accepted: 07/16/2019] [Indexed: 12/14/2022] Open
Abstract
The relationship between gut microbiota and neurological diseases, including chronic pain, has received increasing attention. The gut microbiome is a crucial modulator of visceral pain, whereas recent evidence suggests that gut microbiota may also play a critical role in many other types of chronic pain, including inflammatory pain, headache, neuropathic pain, and opioid tolerance. We present a narrative review of the current understanding on the role of gut microbiota in pain regulation and discuss the possibility of targeting gut microbiota for the management of chronic pain. Numerous signalling molecules derived from gut microbiota, such as by-products of microbiota, metabolites, neurotransmitters, and neuromodulators, act on their receptors and remarkably regulate the peripheral and central sensitisation, which in turn mediate the development of chronic pain. Gut microbiota-derived mediators serve as critical modulators for the induction of peripheral sensitisation, directly or indirectly regulating the excitability of primary nociceptive neurones. In the central nervous system, gut microbiota-derived mediators may regulate neuroinflammation, which involves the activation of cells in the blood-brain barrier, microglia, and infiltrating immune cells, to modulate induction and maintenance of central sensitisation. Thus, we propose that gut microbiota regulates pain in the peripheral and central nervous system, and targeting gut microbiota by diet and pharmabiotic intervention may represent a new therapeutic strategy for the management of chronic pain.
Collapse
|
48
|
Crosson T, Roversi K, Balood M, Othman R, Ahmadi M, Wang JC, Seadi Pereira PJ, Tabatabaei M, Couture R, Eichwald T, Latini A, Prediger RD, Rangachari M, Seehus CR, Foster SL, Talbot S. Profiling of how nociceptor neurons detect danger - new and old foes. J Intern Med 2019; 286:268-289. [PMID: 31282104 DOI: 10.1111/joim.12957] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The host evolves redundant mechanisms to preserve physiological processing and homeostasis. These functions range from sensing internal and external threats, creating a memory of the insult and generating reflexes, which aim to resolve inflammation. Impairment in such functioning leads to chronic inflammatory diseases. By interacting through a common language of ligands and receptors, the immune and sensory nervous systems work in concert to accomplish such protective functions. Whilst this bidirectional communication helps to protect from danger, it can contribute to disease pathophysiology. Thus, the somatosensory nervous system is anatomically positioned within primary and secondary lymphoid tissues and mucosa to modulate immunity directly. Upstream of this interplay, neurons detect danger, which prompts the release of neuropeptides initiating (i) defensive reflexes (ranging from withdrawal response to coughing) and (ii) chemotaxis, adhesion and local infiltration of immune cells. The resulting outcome of such neuro-immune interplay is still ill-defined, but consensual findings start to emerge and support neuropeptides not only as blockers of TH 1-mediated immunity but also as drivers of TH 2 immune responses. However, the modalities detected by nociceptors revealed broader than mechanical pressure and temperature sensing and include signals as various as cytokines and pathogens to immunoglobulins and even microRNAs. Along these lines, we aggregated various dorsal root ganglion sensory neuron expression profiling datasets supporting such wide-ranging sensing capabilities to help identifying new danger detection modalities of these cells. Thus, revealing unexpected aspects of nociceptor neuron biology might prompt the identification of novel drivers of immunity, means to resolve inflammation and strategies to safeguard homeostasis.
Collapse
Affiliation(s)
- T Crosson
- From the, Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada
| | - K Roversi
- From the, Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada.,Departamento de Farmacologia Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - M Balood
- From the, Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada.,Axe Neurosciences, Centre de recherche du CHU, Université Laval, Québec, QC, Canada.,Département de Médecine Moléculaire, Faculté de Médecine, Université Laval, Québec, QC, Canada
| | - R Othman
- From the, Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada
| | - M Ahmadi
- From the, Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada
| | - J-C Wang
- From the, Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada.,Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | | | - M Tabatabaei
- From the, Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada
| | - R Couture
- From the, Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada
| | - T Eichwald
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - A Latini
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - R D Prediger
- Departamento de Farmacologia Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - M Rangachari
- Axe Neurosciences, Centre de recherche du CHU, Université Laval, Québec, QC, Canada.,Département de Médecine Moléculaire, Faculté de Médecine, Université Laval, Québec, QC, Canada
| | - C R Seehus
- FM Kirby Neurobiology Center, Children's Hospital, Boston, MA, USA
| | - S L Foster
- Depression Clinical Research Program, Massachusetts General Hospital, Boston, MA, USA
| | - S Talbot
- From the, Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada
| |
Collapse
|
49
|
Zhang Z, Zhang X, Zhang Y, Li J, Xing Z, Zhang Y. Spinal circRNA-9119 Suppresses Nociception by Mediating the miR-26a-TLR3 Axis in a Bone Cancer Pain Mouse Model. J Mol Neurosci 2019; 70:9-18. [PMID: 31368062 DOI: 10.1007/s12031-019-01378-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 07/09/2019] [Indexed: 12/28/2022]
Abstract
Altered expression of circular RNA (circRNA) is recognized as a contributor to malignant pain where microRNA (miRNA) exerts an essential effect. We generated a murine model for bone malignancy pain in which 2472 osteolytic sarcoma cells were injected into the femurs of mice. CircRNA microarray and quantitative PCR (qPCR) and revealed that circ9119 expression was repressed in the spinal cord of bone malignancy pain model mice, which is the first relay site involved in the transmission of nociceptive information to the cerebrum of mice that receive spinal analgesics for malignancy pain. Overexpression of circ9119 by plasmid injection in the model mice reduced progressive thermal hyperalgesia and mechanical hyperalgesia. Bioinformatics prediction and dual-luciferase reporter assay showed that circ9119 functions as a sponge of miR-26a, which targets the TLR3 3'-untranslated region. Furthermore, expression of miR-26a was elevated and TLR3 level was repressed in bone malignancy pain model mice, which were counteracted by circ9119 in the spinal cord of tumor-bearing mice. Moreover, excessive expression of miR-26a was involved in the recovery of mice from progressive thermal hyperalgesia and mechanical hyperalgesia triggered via circ9119. TLR3 knockdown in bone malignancy pain model mice thoroughly impaired pain in the initial stages and reduced the effects of circ9119 on hyperalgesia. Our research findings indicate that targeting the circ9119-miR-26a-TLR3 axis may be a promising analgesic strategy to manage malignancy pain.
Collapse
Affiliation(s)
- Zhongqi Zhang
- Department of Anesthesiology, Shunde Hospital of Southern Medical University, No. 1 Lunjiaojiazi Road, Shunde District, Foshan, 528308, Guangdong, China
| | - Xiaoxia Zhang
- Department of Anesthesiology, Shunde Hospital of Southern Medical University, No. 1 Lunjiaojiazi Road, Shunde District, Foshan, 528308, Guangdong, China
| | - Yanjing Zhang
- Department of Anesthesiology, Shunde Hospital of Southern Medical University, No. 1 Lunjiaojiazi Road, Shunde District, Foshan, 528308, Guangdong, China
| | - Jiyuan Li
- Department of Anesthesiology, Shunde Hospital of Southern Medical University, No. 1 Lunjiaojiazi Road, Shunde District, Foshan, 528308, Guangdong, China
| | - Zumin Xing
- Department of Anesthesiology, Shunde Hospital of Southern Medical University, No. 1 Lunjiaojiazi Road, Shunde District, Foshan, 528308, Guangdong, China.
| | - Yiwen Zhang
- Department of Anesthesiology, Shunde Hospital of Southern Medical University, No. 1 Lunjiaojiazi Road, Shunde District, Foshan, 528308, Guangdong, China.
| |
Collapse
|
50
|
Datta G, Miller NM, Afghah Z, Geiger JD, Chen X. HIV-1 gp120 Promotes Lysosomal Exocytosis in Human Schwann Cells. Front Cell Neurosci 2019; 13:329. [PMID: 31379513 PMCID: PMC6650616 DOI: 10.3389/fncel.2019.00329] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 07/03/2019] [Indexed: 12/31/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) associated neuropathy is the most common neurological complication of HIV-1, with debilitating pain affecting the quality of life. HIV-1 gp120 plays an important role in the pathogenesis of HIV neuropathy via direct neurotoxic effects or indirect pro-inflammatory responses. Studies have shown that gp120-induced release of mediators from Schwann cells induce CCR5-dependent DRG neurotoxicity, however, CCR5 antagonists failed to improve pain in HIV- infected individuals. Thus, there is an urgent need for a better understanding of neuropathic pain pathogenesis and developing effective therapeutic strategies. Because lysosomal exocytosis in Schwann cells is an indispensable process for regulating myelination and demyelination, we determined the extent to which gp120 affected lysosomal exocytosis in human Schwann cells. We demonstrated that gp120 promoted the movement of lysosomes toward plasma membranes, induced lysosomal exocytosis, and increased the release of ATP into the extracellular media. Mechanistically, we demonstrated lysosome de-acidification, and activation of P2X4 and VNUT to underlie gp120-induced lysosome exocytosis. Functionally, we demonstrated that gp120-induced lysosome exocytosis and release of ATP from Schwann cells leads to increases in intracellular calcium and generation of cytosolic reactive oxygen species in DRG neurons. Our results suggest that gp120-induced lysosome exocytosis and release of ATP from Schwann cells and DRG neurons contribute to the pathogenesis of HIV-1 associated neuropathy.
Collapse
Affiliation(s)
- Gaurav Datta
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, United States
| | - Nicole M Miller
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, United States
| | - Zahra Afghah
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, United States
| | - Jonathan D Geiger
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, United States
| | - Xuesong Chen
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, United States
| |
Collapse
|