1
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Hao Y, Wu L, Wang Y, Shan D, Liu Y, Feng J, Chang Y, Wang T. LPS exacerbates TRPV4-mediated itch through the intracellular TLR4-PI3K signalling. J Cell Mol Med 2024; 28:e18509. [PMID: 38957035 PMCID: PMC11220342 DOI: 10.1111/jcmm.18509] [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: 09/25/2023] [Revised: 06/03/2024] [Accepted: 06/05/2024] [Indexed: 07/04/2024] Open
Abstract
Pruritus is often accompanied with bacterial infections, but the underlying mechanism is not fully understood. Although previous studies revealed that lipopolysaccharides (LPS) could directly activate TRPV4 channel and TRPV4 is involved in the generation of both acute itch and chronic itch, whether and how LPS affects TRPV4-mediated itch sensation remains unclear. Here, we showed that LPS-mediated TRPV4 sensitization exacerbated GSK101-induced scratching behaviour in mice. Moreover, this effect was compromised in TLR4-knockout mice, suggesting LPS acted through a TLR4-dependent mechanism. Mechanistically, LPS enhanced GSK101-evoked calcium influx in mouse ear skin cells and HEK293T cells transfected with TRPV4. Further, LPS sensitized TRPV4 channel through the intracellular TLR4-PI3K-AKT signalling. In summary, our study found a modulatory role of LPS in TRPV4 function and highlighted the TLR4-TRPV4 interaction in itch signal amplification.
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Affiliation(s)
- Yanping Hao
- Shanghai Institute of Materia Medica, Chinese Academy of SciencesShanghaiChina
- University of Chinese Academy of SciencesBeijingChina
- Yangpu Hospital, School of MedicineTongji UniversityShanghaiChina
| | - Liyan Wu
- Shanghai Institute of Materia Medica, Chinese Academy of SciencesShanghaiChina
- University of Chinese Academy of SciencesBeijingChina
| | - Yuhui Wang
- Department of Anesthesiology, Plastic Surgery HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
| | - Dongmei Shan
- Shanghai Institute of Materia Medica, Chinese Academy of SciencesShanghaiChina
- University of Chinese Academy of SciencesBeijingChina
| | - Yifei Liu
- Shanghai Institute of Materia Medica, Chinese Academy of SciencesShanghaiChina
| | - Jing Feng
- Shanghai Institute of Materia Medica, Chinese Academy of SciencesShanghaiChina
- University of Chinese Academy of SciencesBeijingChina
| | - Yi Chang
- Yangpu Hospital, School of MedicineTongji UniversityShanghaiChina
| | - Ting Wang
- Shanghai Institute of Materia Medica, Chinese Academy of SciencesShanghaiChina
- University of Chinese Academy of SciencesBeijingChina
- Yunnan Key Laboratory of Gastrodia and Fungi Symbiotic BiologyZhaotong UniversityZhaotongYunnanChina
- Yunnan Engineering Research Center of Green Planting and Processing of GastrodiaZhaotong UniversityZhaotongYunnanChina
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2
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Gervason S, Meleine M, Lolignier S, Meynier M, Daugey V, Birer A, Aissouni Y, Berthon JY, Ardid D, Filaire E, Carvalho FA. Antihyperalgesic properties of gut microbiota: Parabacteroides distasonis as a new probiotic strategy to alleviate chronic abdominal pain. Pain 2024; 165:e39-e54. [PMID: 37756665 DOI: 10.1097/j.pain.0000000000003075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 08/08/2023] [Indexed: 09/29/2023]
Abstract
ABSTRACT The potential role of gut microbiota in pain modulation is arousing an emerging interest since recent years. This study investigated neuromodulatory properties of gut microbiota to identify next-generation probiotics to propose alternative therapies for visceral pain management. Neuromodulation ability of 10 bacterial strains isolated from a healthy donor was assessed both on ND7/23 immortalized cell line and primary neuronal cells from rat dorsal root ganglia. This screening highlighted the neuroinhibitory property of Parabacteroides distasonis (F1-2) strain, supported both by its intracellular content and membrane fraction, which was further investigated in visceral pain mouse models. Oral administration of F1-2 resulted in a significant decrease of colonic hypersensitivity (CHS) in dextran sulfate sodium (0.5%) model associated with low-grade inflammation and a significant decrease of CHS in Citrobacter rodentium postinfectious models. No effect of F1-2 oral administration on CHS was observed in a neonatal maternal separation stress model. Antihyperalgesic effect unlikely involved modulation of inflammatory processes or restoration of intestinal barrier. Exploration of direct dialogue mechanisms between this strain and nervous system, assessed by calcium imaging experiments, revealed that F1-2 interacts directly with nociceptors by reducing activation level on capsaicin, inflammatory soup, and bradykinin stimulations. Our study provides new insights about bacteria-host interaction and places P distasonis as a potential therapeutic strategy in the treatment of visceral pain observed in leaky gut-associated pathologies.
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Affiliation(s)
- Sandie Gervason
- NeuroDol, UMR 1107 INSERM, University of Clermont Auvergne, Clermont-Ferrand, France
| | - Mathieu Meleine
- NeuroDol, UMR 1107 INSERM, University of Clermont Auvergne, Clermont-Ferrand, France
| | - Stéphane Lolignier
- NeuroDol, UMR 1107 INSERM, University of Clermont Auvergne, Clermont-Ferrand, France
| | - Maëva Meynier
- NeuroDol, UMR 1107 INSERM, University of Clermont Auvergne, Clermont-Ferrand, France
- M2iSH, UMR 1071 INSERM, University of Clermont Auvergne, Clermont-Ferrand, France
| | - Valentine Daugey
- NeuroDol, UMR 1107 INSERM, University of Clermont Auvergne, Clermont-Ferrand, France
| | - Aurélien Birer
- M2iSH, UMR 1071 INSERM, University of Clermont Auvergne, Clermont-Ferrand, France
- Centre National de Référence de la Résisitance aux Antibiotiques, Service de Bactériologie, Clermont-Ferrand, France
| | - Youssef Aissouni
- NeuroDol, UMR 1107 INSERM, University of Clermont Auvergne, Clermont-Ferrand, France
| | | | - Denis Ardid
- NeuroDol, UMR 1107 INSERM, University of Clermont Auvergne, Clermont-Ferrand, France
| | - Edith Filaire
- ECREIN Team, Human Nutrition Unit (UNH), UMR 1019 INRAE-UCA, University of Clermont-Auvergne, Clermont-Ferrand, France
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3
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Diogenes A. A Case of Respiratory Epithelium-Lined Cyst with Enriched Nociceptor Innervation. J Endod 2024; 50:389-394. [PMID: 38141830 DOI: 10.1016/j.joen.2023.12.003] [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] [Received: 11/14/2023] [Revised: 12/15/2023] [Accepted: 12/16/2023] [Indexed: 12/25/2023]
Abstract
Apical lesions of endodontic origin can be classified as either granulomas or cysts. In rare cases, respiratory epithelium can proliferate and encapsulate a lesion, forming a cyst. Moreover, the innervation of apical lesions has only been previously reported in animal models of apical periodontitis. This report demonstrates an unusual case in which tooth #15 was initially treated with nonsurgical root canal therapy. Still, the patient remained in moderate to severe pain for several days following the procedure. Next, an intentional replantation was performed in which a periapical cyst was curetted from the alveolus. The patient experienced immediate pain relief following the procedure. Histological analysis revealed that the periapical cyst was lined entirely with respiratory epithelium, and immunohistochemical analysis showed it to be densely innervated. In addition, these nerve fibers expressed the LPS receptor, TLR4. This is the first demonstration of the innervation pattern of a periapical cyst. Further studies are warranted to evaluate innervation in apical lesions and its correlation with pre- and intra-operative symptoms and their participation in the pathogenesis of apical periodontitis.
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Affiliation(s)
- Anibal Diogenes
- Department of Endodontics, University of Texas Health San Antonio, San Antonio, Texas.
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4
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Amin MF, Ariwibowo T, Putri SA, Kurnia D. Moringa oleifera: A Review of the Pharmacology, Chemical Constituents, and Application for Dental Health. Pharmaceuticals (Basel) 2024; 17:142. [PMID: 38276015 PMCID: PMC10819732 DOI: 10.3390/ph17010142] [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: 11/14/2023] [Revised: 01/13/2024] [Accepted: 01/16/2024] [Indexed: 01/27/2024] Open
Abstract
Moringa oleifera L., commonly known as Kelor in Indonesia and miracle tree in English, has a rich history of utilization for medicinal, nutritional, and water treatment purposes dating back to ancient times. The plant is renowned for its abundance of vitamins, minerals, and various chemical constituents, making it a valuable resource. Among its notable pharmacological properties are its effectiveness as an anti-diabetic, anti-diarrheal, anti-helmintic, anti-leishmanial, anti-fungal, anti-bacterial, anti-allergic, anti-cancer, anti-inflammatory, and anti-oxidant agent. In this comprehensive review, we delve into the extensive pharmacological applications and phytochemical constituents of M. oleifera and its application in dental health.
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Affiliation(s)
- Meiny Faudah Amin
- Department Conservative Dentistry, Faculty of Dentistry, Universitas Trisakt, Jakarta Barat 11440, Indonesia;
| | - Taufiq Ariwibowo
- Department Conservative Dentistry, Faculty of Dentistry, Universitas Trisakt, Jakarta Barat 11440, Indonesia;
| | - Salsabila Aqila Putri
- Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, Sumedang 45363, Indonesia; (S.A.P.); (D.K.)
| | - Dikdik Kurnia
- Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, Sumedang 45363, Indonesia; (S.A.P.); (D.K.)
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5
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Patel B, Eskander MA, Fang-Mei Chang P, Chapa B, Ruparel SB, Lai Z, Chen Y, Akopian A, Ruparel NB. Understanding painful versus non-painful dental pain in female and male patients: A transcriptomic analysis of human biopsies. PLoS One 2023; 18:e0291724. [PMID: 37733728 PMCID: PMC10513205 DOI: 10.1371/journal.pone.0291724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 09/05/2023] [Indexed: 09/23/2023] Open
Abstract
Dental pain from apical periodontitis is an infection induced-orofacial pain condition that presents with diversity in pain phenotypes among patients. While 60% of patients with a full-blown disease present with the hallmark symptom of mechanical allodynia, nearly 40% of patients experience no pain. Furthermore, a sexual dichotomy exists, with females exhibiting lower mechanical thresholds under basal and diseased states. Finally, the prevalence of post-treatment pain refractory to commonly used analgesics ranges from 7-19% (∼2 million patients), which warrants a thorough investigation of the cellular changes occurring in different patient cohorts. We, therefore, conducted a transcriptomic assessment of periapical biopsies (peripheral diseased tissue) from patients with persistent apical periodontitis. Surgical biopsies from symptomatic male (SM), asymptomatic male (AM), symptomatic female (SF), and asymptomatic female (AF) patients were collected and processed for bulk RNA sequencing. Using strict selection criteria, our study found several unique differentially regulated genes (DEGs) between symptomatic and asymptomatic patients, as well as novel candidate genes between sexes within the same pain group. Specifically, we found the role of cells of the innate and adaptive immune system in mediating nociception in symptomatic patients and the role of genes involved in tissue homeostasis in potentially inhibiting nociception in asymptomatic patients. Furthermore, sex-related differences appear to be tightly regulated by macrophage activity, its secretome, and/or migration. Collectively, we present, for the first time, a comprehensive assessment of peripherally diseased human tissue after a microbial insult and shed important insights into the regulation of the trigeminal system in female and male patients.
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Affiliation(s)
- Biraj Patel
- Department of Endodontics, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Michael A. Eskander
- Department of Endodontics, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Phoebe Fang-Mei Chang
- Department of Endodontics, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Brett Chapa
- Department of Endodontics, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Shivani B. Ruparel
- Department of Endodontics, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Zhao Lai
- Greehey Children’s Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
- Department of Molecular Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Yidong Chen
- Greehey Children’s Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
- Department of Population Health Sciences, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Armen Akopian
- Department of Endodontics, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Nikita B. Ruparel
- Department of Endodontics, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
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6
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Menon N, Kishen A. Nociceptor-Macrophage Interactions in Apical Periodontitis: How Biomolecules Link Inflammation with Pain. Biomolecules 2023; 13:1193. [PMID: 37627258 PMCID: PMC10452348 DOI: 10.3390/biom13081193] [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] [Received: 06/20/2023] [Revised: 07/20/2023] [Accepted: 07/24/2023] [Indexed: 08/27/2023] Open
Abstract
Periradicular tissues have a rich supply of peripheral afferent neurons, also known as nociceptive neurons, originating from the trigeminal nerve. While their primary function is to relay pain signals to the brain, these are known to be involved in modulating innate and adaptive immunity by initiating neurogenic inflammation (NI). Studies have investigated neuroanatomy and measured the levels of biomolecules such as cytokines and neuropeptides in human saliva, gingival crevicular fluid, or blood/serum samples in apical periodontitis (AP) to validate the possible role of trigeminal nociceptors in inflammation and tissue regeneration. However, the contributions of nociceptors and the mechanisms involved in the neuro-immune interactions in AP are not fully understood. This narrative review addresses the complex biomolecular interactions of trigeminal nociceptors with macrophages, the effector cells of the innate immune system, in the clinical manifestations of AP.
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Affiliation(s)
| | - Anil Kishen
- Dental Research Institute, Faculty of Dentistry, University of Toronto, Toronto, ON M5G 1G6, Canada;
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7
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Siddiqui YD, Nie X, Wang S, Abbasi Y, Park L, Fan X, Thumbigere-Math V, Chung MK. Substance P aggravates ligature-induced periodontitis in mice. Front Immunol 2023; 14:1099017. [PMID: 37122730 PMCID: PMC10140340 DOI: 10.3389/fimmu.2023.1099017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 03/23/2023] [Indexed: 05/02/2023] Open
Abstract
Periodontitis is one of the most common oral diseases in humans, affecting over 40% of adult Americans. Pain-sensing nerves, or nociceptors, sense local environmental changes and often contain neuropeptides. Recent studies have suggested that nociceptors magnify host response and regulate bone loss in the periodontium. A subset of nociceptors projected to periodontium contains neuropeptides, such as calcitonin gene-related peptide (CGRP) or substance P (SP). However, the specific roles of neuropeptides from nociceptive neural terminals in periodontitis remain to be determined. In this study, we investigated the roles of neuropeptides on host responses and bone loss in ligature-induced periodontitis. Deletion of tachykinin precursor 1 (Tac1), a gene that encodes SP, or treatment of gingiva with SP antagonist significantly reduced bone loss in ligature-induced periodontitis, whereas deletion of calcitonin related polypeptide alpha (Calca), a gene that encodes CGRP, showed a marginal role on bone loss. Ligature-induced recruitment of leukocytes, including neutrophils, and increase in cytokines leading to bone loss in periodontium was significantly less in Tac1 knockout mice. Furthermore, intra-gingival injection of SP, but not neurokinin A, induced a vigorous inflammatory response and osteoclast activation in alveolar bone and facilitated bone loss in ligature-induced periodontitis. Altogether, our data suggest that SP plays significant roles in regulating host responses and bone resorption in ligature-induced periodontitis.
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Affiliation(s)
- Yasir Dilshad Siddiqui
- Program in Neuroscience, Center to Advance Chronic Pain Research, Department of Neural and Pain Sciences, School of Dentistry, University of Maryland, Baltimore, MD, United States
- Department of Preventive Dentistry, College of Dentistry, Jouf University, Sakaka, Saudi Arabia
| | - Xuguang Nie
- Program in Neuroscience, Center to Advance Chronic Pain Research, Department of Neural and Pain Sciences, School of Dentistry, University of Maryland, Baltimore, MD, United States
| | - Sheng Wang
- Program in Neuroscience, Center to Advance Chronic Pain Research, Department of Neural and Pain Sciences, School of Dentistry, University of Maryland, Baltimore, MD, United States
| | - Yasaman Abbasi
- Program in Neuroscience, Center to Advance Chronic Pain Research, Department of Neural and Pain Sciences, School of Dentistry, University of Maryland, Baltimore, MD, United States
| | - Lauren Park
- Program in Neuroscience, Center to Advance Chronic Pain Research, Department of Neural and Pain Sciences, School of Dentistry, University of Maryland, Baltimore, MD, United States
| | - Xiaoxuan Fan
- Department of Microbiology and Immunology, Flow Cytometry Shared Service, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Vivek Thumbigere-Math
- Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, MD, United States
| | - Man-Kyo Chung
- Program in Neuroscience, Center to Advance Chronic Pain Research, Department of Neural and Pain Sciences, School of Dentistry, University of Maryland, Baltimore, MD, United States
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8
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Oral and Intestinal Bacterial Substances Associated with Disease Activities in Patients with Rheumatoid Arthritis: A Cross-Sectional Clinical Study. J Immunol Res 2022; 2022:6839356. [PMID: 35224112 PMCID: PMC8881124 DOI: 10.1155/2022/6839356] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Revised: 01/19/2022] [Accepted: 01/27/2022] [Indexed: 01/02/2023] Open
Abstract
Intestinal bacterial compositions of rheumatoid arthritis (RA) patients have been reported to be different from those of healthy people. Dysbiosis, imbalance of the microbiota, is widely known to cause gut barrier damage, resulting in an influx of bacteria and their substances into host bloodstreams in animal studies. However, few studies have investigated the effect of bacterial substances on the pathophysiology of RA. In this study, eighty-seven active RA patients who had inadequate responses to conventional synthetic disease-modifying antirheumatic drugs or severe comorbidities were analyzed for correlations between many factors such as disease activities, disease biomarkers, intestinal bacterial counts, fecal and serum lipopolysaccharide (LPS), LPS-binding protein (LBP), endotoxin neutralizing capacity (ENC), and serum antibacterial substance IgG and IgA antibody levels by multiple regression analysis with consideration for demographic factors such as age, sex, smoking, and methotrexate treatment. Serum LBP levels, fecal LPS levels, total bacteria counts, serum anti-LPS from Porphyromonas gingivalis (Pg-LPS) IgG antibody levels, and serum anti-Pg-LPS IgA antibody levels were selected for multiple regression analysis using Spearman’s correlation analysis. Serum LBP levels were correlated with disease biomarker levels, such as erythrocyte sedimentation rate (
), C-reactive protein (
), matrix metalloproteinase-3 (
), and IL-6 (
), and were inversely correlated with hemoglobin (
). Anti-Pg-LPS IgG antibody levels were inversely correlated with activity indices such as patient global assessments using visual analogue scale (VAS) (
) and painVAS (
). Total bacteria counts were correlated with ENC (
), and inversely correlated with serum LPS (
) and anti-Pg-LPS IgA antibody levels (
). These results suggest that substances from oral and gut microbiota may influence disease activity in RA patients.
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9
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Mustafa S, Evans S, Barry B, Barratt D, Wang Y, Lin C, Wang X, Hutchinson MR. Toll-Like Receptor 4 in Pain: Bridging Molecules-to-Cells-to-Systems. Handb Exp Pharmacol 2022; 276:239-273. [PMID: 35434749 DOI: 10.1007/164_2022_587] [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] [Indexed: 06/14/2023]
Abstract
Pain impacts the lives of billions of people around the world - both directly and indirectly. It is complex and transcends beyond an unpleasant sensory experience to encompass emotional experiences. To date, there are no successful treatments for sufferers of chronic pain. Although opioids do not provide any benefit to chronic pain sufferers, they are still prescribed, often resulting in more complications such as hyperalgesia and dependence. In order to develop effective and safe medications to manage, and perhaps even treat pain, it is important to evaluate novel contributors to pain pathologies. As such, in this chapter we review the role of Toll-like receptor 4, a receptor of the innate immune system, that continues to gain substantial attention in the field of pain research. Positioned in the nexus of the neuro and immune systems, TLR4 may provide one of the missing pieces in understanding the complexities of pain. Here we consider how TLR4 enables a mechanistical understanding of pain as a multidimensional biopsychosocial state from molecules to cells to systems and back again.
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Affiliation(s)
- Sanam Mustafa
- Adelaide Medical School, The University of Adelaide, Adelaide, SA, Australia.
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, The University of Adelaide, Adelaide, SA, Australia.
| | - Samuel Evans
- Adelaide Medical School, The University of Adelaide, Adelaide, SA, Australia
| | - Benjamin Barry
- Adelaide Medical School, The University of Adelaide, Adelaide, SA, Australia
| | - Daniel Barratt
- Adelaide Medical School, The University of Adelaide, Adelaide, SA, Australia
| | - Yibo Wang
- Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, China
| | - Cong Lin
- Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, China
| | - Xiaohui Wang
- Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, Anhui, China
| | - Mark R Hutchinson
- Adelaide Medical School, The University of Adelaide, Adelaide, SA, Australia
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, The University of Adelaide, Adelaide, SA, Australia
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10
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Michot B, Casey SM, Gibbs JL. Effects of CGRP-Primed Dental Pulp Stem Cells on Trigeminal Sensory Neurons. J Dent Res 2021; 100:1273-1280. [PMID: 33840300 DOI: 10.1177/00220345211004872] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Dental pulp stem cells (DPSCs) are important in tooth physiology, contributing to development, repair, regeneration, and immunomodulatory processes. However, their role in inflammatory mechanisms underlying pulpitis is not well understood. We evaluated the influence of DPSCs stimulated with calcitonin gene-related peptide (CGRP), a proinflammatory neuropeptide, on the expression of mediators released from DPSCs and the effect of these mediators on sensory neuron activity. Human DPSCs were treated with either control media or media containing CGRP (10-8 M) for 7 d, and the conditioned media (CM) containing DPSC-released mediators was collected. The expression of cytokines and chemokines from DPSCs was evaluated by reverse transcription quantitative polymerase chain reaction. The effects of the CM from CGRP-primed DPSCs (primed DPSC-CM) were evaluated on sensory afferents by using primary cultures of mouse trigeminal neurons and an organotypic model of cultured human pulp slices. Mouse trigeminal neurons and human pulp explants were pretreated for 24 h with control or primed DPSC-CM and then stimulated with capsaicin. Afferent activity was measured by quantifying the response to capsaicin via live cell calcium imaging in mouse neurons and CGRP released from pulp explants. Gene expression analysis showed that primed DPSCs overexpressed some proinflammatory cytokines and chemokines, including chemokines CXCL1 and CXCL8, which are both agonists of the receptor CXCR2 expressed in sensory neurons. Primed DPSC-CM increased human pulp sensory afferent activity as compared with control DPSC-CM. Similarly, primed DPSC-CM increased the intensity of calcium responses in cultured mouse trigeminal neurons. Furthermore, the CXCR2 antagonist SB225002 prevented trigeminal neuron sensitization to capsaicin induced by primed DPSC-CM. In conclusion, mediators released by DPSCs, primed with the proinflammatory mediator CGRP, induce neuronal sensitization through CXCR2 receptor. These data suggest that DPSCs might contribute to pain symptoms that develop in pulpitis.
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Affiliation(s)
- B Michot
- Department of Restorative Dentistry and Biomaterials Sciences, Harvard School of Dental Medicine, Boston, MA, USA.,Department of Endodontics, College of Dentistry, New York University, New York, NY, USA
| | - S M Casey
- Department of Restorative Dentistry and Biomaterials Sciences, Harvard School of Dental Medicine, Boston, MA, USA.,Department of Endodontics, College of Dentistry, New York University, New York, NY, USA
| | - J L Gibbs
- Department of Restorative Dentistry and Biomaterials Sciences, Harvard School of Dental Medicine, Boston, MA, USA.,Department of Endodontics, College of Dentistry, New York University, New York, NY, USA
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11
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Araya EI, Barroso AR, Turnes JDM, Radulski DR, Jaganaught JRA, Zampronio AR, Chichorro JG. Toll-like receptor 4 (TLR4) signaling in the trigeminal ganglion mediates facial mechanical and thermal hyperalgesia in rats. Physiol Behav 2020; 226:113127. [DOI: 10.1016/j.physbeh.2020.113127] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 08/04/2020] [Accepted: 08/05/2020] [Indexed: 02/07/2023]
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12
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Zhan C, Huang M, Yang X, Hou J. Dental nerves: a neglected mediator of pulpitis. Int Endod J 2020; 54:85-99. [PMID: 32880979 DOI: 10.1111/iej.13400] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Accepted: 08/26/2020] [Indexed: 12/18/2022]
Abstract
As one of the most densely innervated tissues, the dental pulp contains abundant nerve fibres, including sensory, sympathetic and parasympathetic nerve fibres. Studies in animal models and human patients with pulpitis have revealed distinct alterations in protein expression and histological appearance in all types of dental nerve fibres. Various molecules secreted by neurons, such as classical neurotransmitters, neuropeptides and amino acids, not only contribute to the induction, sensitization and maintenance of tooth pain, but also regulate non-neuronal cells, including fibroblasts, odontoblasts, immune cells and vascular endothelial cells. Dental nerves are particularly important for the microcirculatory and immune responses in pulpitis via their release of a variety of functional substances. Further, nerve fibres are found to be involved in dental soft and hard tissue repair. Thus, understanding how dental nerves participate in pulpitis could have important clinical ramifications for endodontic treatment. In this review, the roles of dental nerves in regulating pulpal inflammatory processes are highlighted and their implications for future research on this topic are discussed.
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Affiliation(s)
- C Zhan
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - M Huang
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - X Yang
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - J Hou
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China
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13
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Lin B, Wang Y, Zhang P, Yuan Y, Zhang Y, Chen G. Gut microbiota regulates neuropathic pain: potential mechanisms and therapeutic strategy. J Headache Pain 2020; 21:103. [PMID: 32807072 PMCID: PMC7433133 DOI: 10.1186/s10194-020-01170-x] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 08/10/2020] [Indexed: 02/08/2023] Open
Abstract
Neuropathic pain (NP) is a sustained and nonreversible condition characterized by long-term devastating physical and psychological damage. Therefore, it is urgent to identify an effective treatment for NP. Unfortunately, the precise pathogenesis of NP has not been elucidated. Currently, the microbiota-gut-brain axis has drawn increasing attention, and the emerging role of gut microbiota is investigated in numerous diseases including NP. Gut microbiota is considered as a pivotal regulator in immune, neural, endocrine, and metabolic signaling pathways, which participates in forming a complex network to affect the development of NP directly or indirectly. In this review, we conclude the current understanding of preclinical and clinical findings regarding the role of gut microbiota in NP and provide a novel therapeutic method for pain relief by medication and dietary interventions.
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Affiliation(s)
- Binbin Lin
- Department of Anesthesiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, 3 Qingchun East Road, Zhejiang, 310016, Hangzhou, China
| | - Yuting Wang
- Department of Anesthesiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, 3 Qingchun East Road, Zhejiang, 310016, Hangzhou, China
| | - Piao Zhang
- Department of Anesthesiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, 3 Qingchun East Road, Zhejiang, 310016, Hangzhou, China
| | - Yanyan Yuan
- Department of Anesthesiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, 3 Qingchun East Road, Zhejiang, 310016, Hangzhou, China
| | - Ying Zhang
- Department of Anesthesiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, 3 Qingchun East Road, Zhejiang, 310016, Hangzhou, China
| | - Gang Chen
- Department of Anesthesiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, 3 Qingchun East Road, Zhejiang, 310016, Hangzhou, China.
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14
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Hu J, Chen W, Qiu Z, Lv H. Robust expression of SIRT6 inhibits pulpitis via activation of the TRPV1 channel. Cell Biochem Funct 2020; 38:676-682. [PMID: 32236974 DOI: 10.1002/cbf.3528] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 03/02/2020] [Accepted: 03/13/2020] [Indexed: 12/20/2022]
Abstract
Invasion of dentinal tubules and pulp tissue by pathogenic bacteria may cause infection leading to pulpitis. Sirtuin 6 (SIRT6) is a NAD-dependent protein deacetylase encoded by the SIRT6 gene. The effect of SIRT6 on lipopolysaccharide (LPS)-induced pulpitis and its mechanism of action were discussed in this study. Dental pulp cells (DPCs) were extracted from human teeth and injected with LPS to induce inflammation. The cells injected with LPS showed substantially decreased expression of SIRT6. The overexpression of SIRT6, induced by plasmid-transfection of DPCs with SIRT6 overexpressing vector, led to a marked decrease in proinflammatory cytokines (IL-6, IL-1β, and TNF-α) and deactivation of NF kappa B pathway. Additionally, dentin matrix protein-1 (DMP1), a promoter of inflammation in dental pulp tissues, was downregulated. Further investigation revealed that SIRT6 promotes ubiquitination of the transient receptor potential vanilloid 1 (TRPV1) channel, leading to its degradation and deactivation. The role of TRPV1 in the anti-inflammatory effects of SIRT6 was determined through incubation of SIRT6-expressing dental pulp stem cells (DPSCs) with capsaicin. This incubation counteracted the effect of SIRT6 on cytokines and DMP1. The injection of lentivirus-SIRT6 attenuated LPS-induced pulpitis in vivo by suppressing TRPV1 activity. Thus, SIRT6 inhibits the TRPV1 channel during LPS-induced inflammation of dental pulp. SIGNIFICANCE OF THE STUDY: This study discussed the effect of sirtuin 6 (SIRT6) on lipopolysaccharide (LPS)-induced pulpitis as well as its mechanism of action and found that SIRT6 may be a negative regulator of pulpitis. Additionally, low expression of SIRT6 and high expression of transient receptor potential vanilloid 1 (TRPV1) in LPS-treated human dental pulp cells are closely associated with proinflammatory cytokines, dentin matrix protein 1 expression, and activation of the NF-κB pathway, which indicated that TRPV1 may be a biomarker for pulpitis and the SIRT6-TRPV1-CGRP axis maybe a clinical target due to their role regulating inflammation and neuropathic pain.
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Affiliation(s)
- Jia Hu
- Department of Endodontics, Affiliated Stomatological Hospital of Fujian Medical University, Fuzhou, Fujian, China.,Fujian Provincial Key Laboratory of Stomatology, Fuzhou, Fujian, China
| | - Weiran Chen
- Fujian Provincial Key Laboratory of Stomatology, Fuzhou, Fujian, China.,Affiliated Stomatological Hospital of Fujian Medical University, Fuzhou, Fujian, China
| | - Zailing Qiu
- Fujian Provincial Key Laboratory of Stomatology, Fuzhou, Fujian, China.,Affiliated Stomatological Hospital of Fujian Medical University, Fuzhou, Fujian, China
| | - Hongbing Lv
- Department of Endodontics, Affiliated Stomatological Hospital of Fujian Medical University, Fuzhou, Fujian, China.,Fujian Provincial Key Laboratory of Stomatology, Fuzhou, Fujian, China
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15
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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
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16
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Mohaved SB, Shilpa G, Li Q, Austah O, Bendele M, Brock R, Ruparel NB. Apical periodontitis-induced mechanical allodynia: A mouse model to study infection-induced chronic pain conditions. Mol Pain 2020; 16:1744806919900725. [PMID: 31902318 PMCID: PMC6977224 DOI: 10.1177/1744806919900725] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Infection-induced chronic pain is an under-studied pain condition. One example is apical periodontitis, which evokes considerable mechanical allodynia that persists after treatment in 7% to 12% of patients. Available analgesics often provide incomplete relief. However, a preclinical model to study pain mechanisms associated with apical periodontitis is not available. Here, we report a mouse model of apical periodontitis to facilitate studies determining mechanisms mediating persistent infection-induced pain. Mice were anesthetized and the left first molar was exposed to the oral environment for six weeks. Bone resorption, as an indicator of apical periodontitis, was quantified using microcomputed tomography. Mechanical allodynia was determined using extraoral von-Frey filaments in both male and female mice. The expression of c-fos in the medullary dorsal horn was assessed using immunohistochemistry. Mice with apical periodontitis developed significant mechanical allodynia by day 7 that was maintained for 42 days. Mechanical thresholds were significantly lower in females compared to males. Administration of ibuprofen, morphine, or MK-801 reversed mechanical allodynia. Finally, apical periodontitis triggered an upregulation of c-fos in the medullary dorsal horn. Collectively, this model simulates signs of clinical pain experienced by patients with apical periodontitis, detects sex differences in allodynia, and permits the study of peripheral and central trigeminal pain mechanisms.
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Affiliation(s)
- Saeed B Mohaved
- Department of Endodontics, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Ganatra Shilpa
- Department of Endodontics, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Qun Li
- Department of Endodontics, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Obadah Austah
- Department of Endodontics, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Michelle Bendele
- Department of Endodontics, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Robert Brock
- Department of Endodontics, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Nikita B Ruparel
- Department of Endodontics, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
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17
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Mazgaeen L, Gurung P. Recent Advances in Lipopolysaccharide Recognition Systems. Int J Mol Sci 2020; 21:ijms21020379. [PMID: 31936182 PMCID: PMC7013859 DOI: 10.3390/ijms21020379] [Citation(s) in RCA: 177] [Impact Index Per Article: 44.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 01/03/2020] [Accepted: 01/05/2020] [Indexed: 02/07/2023] Open
Abstract
Lipopolysaccharide (LPS), commonly known as endotoxin, is ubiquitous and the most-studied pathogen-associated molecular pattern. A component of Gram-negative bacteria, extracellular LPS is sensed by our immune system via the toll-like receptor (TLR)-4. Given that TLR4 is membrane bound, it recognizes LPS in the extracellular milieu or within endosomes. Whether additional sensors, if any, play a role in LPS recognition within the cytoplasm remained unknown until recently. The last decade has seen an unprecedented unfolding of TLR4-independent LPS sensing pathways. First, transient receptor potential (TRP) channels have been identified as non-TLR membrane-bound sensors of LPS and, second, caspase-4/5 (and caspase-11 in mice) have been established as the cytoplasmic sensors for LPS. Here in this review, we detail the brief history of LPS discovery, followed by the discovery of TLR4, TRP as the membrane-bound sensor, and our current understanding of caspase-4/5/11 as cytoplasmic sensors.
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Affiliation(s)
- Lalita Mazgaeen
- Inflammation Program, University of Iowa, Iowa City, IA 52242, USA;
- Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, Iowa City, IA 52242, USA
| | - Prajwal Gurung
- Inflammation Program, University of Iowa, Iowa City, IA 52242, USA;
- Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, Iowa City, IA 52242, USA
- Immunology Graduate Program, University of Iowa, Iowa City, IA 52242, USA
- Correspondence: ; Tel.: +1-(319)335-4536; Fax: +1-(319)335-4194
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18
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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.
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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
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Affiliation(s)
- George J DeMarco
- Department of Animal Medicine, University of Massachusetts Medical School, Worcester, Massachusetts;,
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19
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Iqbal S, Parker LM, Everest-Dass AV, Moh ESX, Sayyadi N, Hutchinson MR, Packer NH. Lipopolysaccharide and Morphine-3-Glucuronide-Induced Immune Signalling Increases the Expression of Polysialic Acid in PC12 Cells. Mol Neurobiol 2019; 57:964-975. [PMID: 31646464 DOI: 10.1007/s12035-019-01791-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 09/22/2019] [Indexed: 11/26/2022]
Abstract
Polysialic acid (polySia), a long homopolymer of 2,8-linked sialic acids, is abundant in the embryonic brain and is restricted largely in adult brain to regions that exhibit neurogenesis and structural plasticity. In the central nervous system (CNS), polySia is highly important for cell-cell interactions, differentiation, migration and cytokine responses, which are critical neuronal functions regulating intercellular interactions that underlie immune signalling in the CNS. In recent reports, a metabolite of morphine, morphine-3-glucuronide (M3G), has been shown to cause immune signalling in the CNS. In this study, we compared the effects of neurite growth factor (NGF), lipopolysaccharide (LPS) and M3G exposure on the expression of polySia in PC12 cells using immunocytochemistry and Western blot analysis. PolySia was also extracted from stimulated cell proteins by endo-neuraminidase digestion and quantitated using fluorescent labelling followed by HPLC analysis. PolySia expression was significantly increased following NGF, M3G or LPS stimulation when compared with unstimulated cells or cells exposed to the TLR4 antagonist LPS-RS. Additionally, we analyzed the effects of test agent exposure on cell migration and the oxidative stress response of these cells in the presence and absence of polySia expression on their cell surface. We observed an increase in oxidative stress in cells without polySia as well as following M3G or LPS stimulation. Our study provides evidence that polySia expression in neuronal-like PC12 cells is influenced by M3G and LPS exposure alike, suggestive of a role of TLR4 in triggering these events.
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Affiliation(s)
- Sameera Iqbal
- Department of Molecular Sciences and ARC Centre of Excellence for Nanoscale Biophotonics, Macquarie University, Sydney, NSW, Australia
| | - Lindsay M Parker
- Department of Molecular Sciences and ARC Centre of Excellence for Nanoscale Biophotonics, Macquarie University, Sydney, NSW, Australia
| | - Arun V Everest-Dass
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia
| | - Edward S X Moh
- Department of Molecular Sciences and ARC Centre of Excellence for Nanoscale Biophotonics, Macquarie University, Sydney, NSW, Australia
| | - Nima Sayyadi
- Department of Molecular Sciences and ARC Centre of Excellence for Nanoscale Biophotonics, Macquarie University, Sydney, NSW, Australia
| | - Mark R Hutchinson
- ARC Centre of Excellence for Nanoscale Biophotonics, University of Adelaide, Adelaide, South Australia, Australia
- Adelaide Medical School, University of Adelaide, Adelaide, South Australia, Australia
| | - Nicolle H Packer
- Department of Molecular Sciences and ARC Centre of Excellence for Nanoscale Biophotonics, Macquarie University, Sydney, NSW, Australia.
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia.
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20
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Martinho FC, de Rabello DGD, Ferreira LL, Nascimento GG. Participation of endotoxin in root canal infections: A systematic review and meta-analysis. Eur J Dent 2019; 11:398-406. [PMID: 28932155 PMCID: PMC5594974 DOI: 10.4103/ejd.ejd_84_17] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
This systematic review and meta-analysis aimed to evaluate the relationship between endotoxin levels and presence of clinical signs/symptoms and radiographic features in patients with endodontic infection. Electronic searches were performed on Medline/PubMed, Embase, Cochrane Library, Scielo, Science Direct, Web of Knowledge and Scopus databases for identification of relevant studies published up to December 2016. Grey literature was searched in Google Scholar. The selected literature was reviewed independently by two authors. Clinical studies evaluating the levels of endotoxin and the presence of clinical and radiographic features were included in this review. In order to determine the relationship between endotoxin levels and presence of clinical signs/symptoms and radiographic features meta-analyses were performed. Among the 385 articles identified in the initial search, 30 were included for full-text appraisal and only eight studies met the inclusion criteria for this systematic review. Meta-analysis revealed that individuals having teeth with tenderness to percussion (TTP) (P = 0.04; I2 57%) and previous episode of pain (PEP) (P = 0.001; I2 81%) had higher levels of endotoxin than their counterparts. Size of radiographic lesion >2 mm (P = 0.02; I2 68%) and presence of root canal exudation (EX) (P = 0.0007; I2 0%) were associated with higher levels of endotoxin. This systematic review and meta-analyses provided a strong evidence that endotoxin are related with the presence of clinical signs/symptoms and radiographic features in patients with endodontic infection.
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Affiliation(s)
- Frederico Canato Martinho
- Department of Restorative Dentistry, São José dos Campos Dental School, State University of São Paulo, São Paulo
| | | | - Luciana Louzada Ferreira
- Department of Restorative Dentistry, São José dos Campos Dental School, State University of São Paulo, São Paulo
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21
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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.
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22
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Qi S, Qian J, Chen F, Zhou P, Yue J, Tang F, Zhang Y, Gong S, Shang G, Cui C, Xu Y. Expression of autophagy‑associated proteins in rat dental irreversible pulpitis. Mol Med Rep 2019; 19:2749-2757. [PMID: 30816453 PMCID: PMC6423575 DOI: 10.3892/mmr.2019.9944] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Accepted: 01/25/2019] [Indexed: 11/23/2022] Open
Abstract
Autophagy serves an important role in numerous diseases, as well as in infection and inflammation. Irreversible pulpitis (IP) is one of the most common inflammatory endodontic diseases, and autophagy has been reported to regulate IP in vitro. However, the level of autophagy in the IP pathogenic process in vivo remains unknown. The aim of the current study was, thus, to investigate the levels of autophagy-associated proteins in rats with IP in vivo. A rat dental IP model was successfully constructed, and five different time points (0, 1, 3, 5 and 7 days) were investigated. The levels of the autophagy-related 5 (ATG5), ATG7, light chain 3 (LC3) and Beclin-1 proteins exhibited a time-dependent increase in rats with IP, whereas the levels of mammalian target of rapamycin and p62/sequestosome 1 were decreased. In addition, the levels of ATG proteins were specifically increased in odontoblasts and microvascular endothelial cells in pulpitis tissue. Based on these findings, autophagy may serve an important role in IP, and the present study data provide a new insight into the IP pathogenesis and treatment.
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Affiliation(s)
- Shengcai Qi
- Department of Stomatology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China
| | - Jun Qian
- Jiangsu Key Laboratory of Oral Diseases, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
| | - Fubo Chen
- Department of Stomatology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China
| | - Peng Zhou
- Jiangsu Key Laboratory of Oral Diseases, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
| | - Jing Yue
- Department of Stomatology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China
| | - Fengqin Tang
- Department of Stomatology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China
| | - Yiming Zhang
- Department of Stomatology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China
| | - Shiqiang Gong
- Center of Stomatology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
| | - Guangwei Shang
- Department of Stomatology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China
| | - Chun Cui
- Center of Stomatology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
| | - Yuanzhi Xu
- Department of Stomatology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China
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23
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Hossain MZ, Bakri MM, Yahya F, Ando H, Unno S, Kitagawa J. The Role of Transient Receptor Potential (TRP) Channels in the Transduction of Dental Pain. Int J Mol Sci 2019; 20:ijms20030526. [PMID: 30691193 PMCID: PMC6387147 DOI: 10.3390/ijms20030526] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Revised: 01/18/2019] [Accepted: 01/24/2019] [Indexed: 12/18/2022] Open
Abstract
Dental pain is a common health problem that negatively impacts the activities of daily living. Dentine hypersensitivity and pulpitis-associated pain are among the most common types of dental pain. Patients with these conditions feel pain upon exposure of the affected tooth to various external stimuli. However, the molecular mechanisms underlying dental pain, especially the transduction of external stimuli to electrical signals in the nerve, remain unclear. Numerous ion channels and receptors localized in the dental primary afferent neurons (DPAs) and odontoblasts have been implicated in the transduction of dental pain, and functional expression of various polymodal transient receptor potential (TRP) channels has been detected in DPAs and odontoblasts. External stimuli-induced dentinal tubular fluid movement can activate TRP channels on DPAs and odontoblasts. The odontoblasts can in turn activate the DPAs by paracrine signaling through ATP and glutamate release. In pulpitis, inflammatory mediators may sensitize the DPAs. They could also induce post-translational modifications of TRP channels, increase trafficking of these channels to nerve terminals, and increase the sensitivity of these channels to stimuli. Additionally, in caries-induced pulpitis, bacterial products can directly activate TRP channels on DPAs. In this review, we provide an overview of the TRP channels expressed in the various tooth structures, and we discuss their involvement in the development of dental pain.
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Affiliation(s)
- Mohammad Zakir Hossain
- Department of Oral Physiology, School of Dentistry, Matsumoto Dental University, 1780 Gobara Hirooka, Shiojiri, Nagano 399-0781, Japan.
| | - Marina Mohd Bakri
- Department of Oral and Craniofacial Sciences, Faculty of Dentistry, University of Malaya, Kuala Lumpur 50603, Malaysia.
| | - Farhana Yahya
- Department of Oral and Craniofacial Sciences, Faculty of Dentistry, University of Malaya, Kuala Lumpur 50603, Malaysia.
| | - Hiroshi Ando
- Department of Biology, School of Dentistry, Matsumoto Dental University, 1780 Gobara, Hirooka, Shiojiri, Nagano 399-0781, Japan.
| | - Shumpei Unno
- Department of Oral Physiology, School of Dentistry, Matsumoto Dental University, 1780 Gobara Hirooka, Shiojiri, Nagano 399-0781, Japan.
| | - Junichi Kitagawa
- Department of Oral Physiology, School of Dentistry, Matsumoto Dental University, 1780 Gobara Hirooka, Shiojiri, Nagano 399-0781, Japan.
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24
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Boonen B, Alpizar YA, Meseguer VM, Talavera K. TRP Channels as Sensors of Bacterial Endotoxins. Toxins (Basel) 2018; 10:toxins10080326. [PMID: 30103489 PMCID: PMC6115757 DOI: 10.3390/toxins10080326] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Revised: 08/02/2018] [Accepted: 08/08/2018] [Indexed: 02/07/2023] Open
Abstract
The cellular and systemic effects induced by bacterial lipopolysaccharides (LPS) have been solely attributed to the activation of the Toll-like receptor 4 (TLR4) signalling cascade. However, recent studies have shown that LPS activates several members of the Transient Receptor Potential (TRP) family of cation channels. Indeed, LPS induces activation of the broadly-tuned chemosensor TRPA1 in sensory neurons in a TLR4-independent manner, and genetic ablation of this channel reduced mouse pain and inflammatory responses triggered by LPS and the gustatory-mediated avoidance to LPS in fruit flies. LPS was also shown to activate TRPV4 channels in airway epithelial cells, an effect leading to an immediate production of bactericidal nitric oxide and to an increase in ciliary beat frequency. In this review, we discuss the role of TRP channels as sensors of bacterial endotoxins, and therefore, as crucial players in the timely detection of invading gram-negative bacteria.
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Affiliation(s)
- Brett Boonen
- Laboratory for Ion Channel Research, Department of Cellular and Molecular Medicine, KU Leuven, VIB Center for Brain & Disease Research, O&N1 Herestraat 49 - box 802, 3000 Leuven, Belgium.
| | - Yeranddy A Alpizar
- Laboratory for Ion Channel Research, Department of Cellular and Molecular Medicine, KU Leuven, VIB Center for Brain & Disease Research, O&N1 Herestraat 49 - box 802, 3000 Leuven, Belgium.
| | - Victor M Meseguer
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, 03550 San Juan de Alicante, Spain.
| | - Karel Talavera
- Laboratory for Ion Channel Research, Department of Cellular and Molecular Medicine, KU Leuven, VIB Center for Brain & Disease Research, O&N1 Herestraat 49 - box 802, 3000 Leuven, Belgium.
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25
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Yu CY, Abbott PV. Pulp microenvironment and mechanisms of pain arising from the dental pulp: From an endodontic perspective. AUST ENDOD J 2018. [DOI: 10.1111/aej.12257] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Christine Y. Yu
- Discipline of Endodontics; UWA Dental School; Oral Health Centre of Western Australia; The University of Western Australia (M512); Crawley Western Australia Australia
| | - Paul V. Abbott
- Discipline of Endodontics; UWA Dental School; Oral Health Centre of Western Australia; The University of Western Australia (M512); Crawley Western Australia Australia
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Diogenes A, Hargreaves KM. Microbial Modulation of Stem Cells and Future Directions in Regenerative Endodontics. J Endod 2018; 43:S95-S101. [PMID: 28844309 DOI: 10.1016/j.joen.2017.07.012] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Regenerative endodontic procedures (REPs) have been shown to promote the resolution of signs and symptoms of disease and increase survival compared with traditional treatment procedures. However, there is still variable predictability of continued root development and evidence that the tissues formed do not recapitulate the native pulp-dentin complex. There is growing evidence that the apical papilla is capable of surviving prolonged endodontic infection and apical periodontitis and that it represents a rich source of undifferentiated mesenchymal stem cells in REPs. The survival and proper differentiation of stem cells transferred into infected root canals are fraught with challenges. Residual antigens, such as lipopolysaccharides, have been shown to be present in dentin even after adequate chemomechanical debridement. These antigens have a profound effect on stem cell fate by modulating their proliferative capacity and postdifferentiation phenotype. Thus, root canals must be detoxified in addition to disinfection. There is a strong need for translational studies that incorporate all aspects of tissue engineering in endodontics in models that include an existing infection to promote further advancement of the field. This is particularly important to make REPs more predictable when treating immature teeth in young patients. Importantly, regenerative procedures could eventually promote tooth longevity in our aging population. Lessons learned from translational studies that best mimic the clinical challenges could be evaluated in pragmatic clinical trials to determine the effectiveness of these procedures to promote desirable patient-centered outcomes.
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Affiliation(s)
- Anibal Diogenes
- Department of Endodontics at University of Texas Health Science Center at San Antonio, San Antonio, Texas.
| | - Kenneth M Hargreaves
- Department of Endodontics at University of Texas Health Science Center at San Antonio, San Antonio, Texas
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Boonen B, Alpizar YA, Sanchez A, López-Requena A, Voets T, Talavera K. Differential effects of lipopolysaccharide on mouse sensory TRP channels. Cell Calcium 2018; 73:72-81. [PMID: 29689522 DOI: 10.1016/j.ceca.2018.04.004] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 03/24/2018] [Accepted: 04/10/2018] [Indexed: 12/24/2022]
Abstract
Acute neurogenic inflammation and pain associated to bacterial infection have been traditionally ascribed to sensitization and activation of sensory nerve afferents secondary to immune cell stimulation. However, we recently showed that lipopolysaccharides (LPS) directly activate the Transient Receptor Potential channels TRPA1 in sensory neurons and TRPV4 in airway epithelial cells. Here we investigated whether LPS activates other sensory TRP channels expressed in sensory neurons. Using intracellular Ca2+ imaging and patch-clamp we determined the effects of LPS on recombinant TRPV1, TRPV2, TRPM3 and TRPM8, heterologously expressed in HEK293T cells. We found that LPS activates TRPV1, although with lower potency than for TRPA1. Activation of TRPV1 by LPS was not affected by mutations of residues required for activation by electrophilic agents or by diacylglycerol and capsaicin. On the other hand, LPS weakly activated TRPM3, activated TRPM8 at 25 °C, but not at 35 °C, and was ineffective on TRPV2. Experiments performed in mouse dorsal root ganglion (DRG) neurons revealed that genetic ablation of Trpa1 did not abolish the responses to LPS, but remain detected in 30% of capsaicin-sensitive cells. The population of neurons responding to LPS was dramatically lower in double Trpa1/Trpv1 KO neurons. Our results show that, in addition to TRPA1, other TRP channels in sensory neurons can be targets of LPS, suggesting that they may contribute to trigger and regulate innate defenses against gram-negative bacterial infections.
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Affiliation(s)
- Brett Boonen
- Laboratory for Ion Channel Research, Department of Cellular and Molecular Medicine, KU Leuven, VIB Center for Brain & Disease Research, O&N1 Herestraat 49 - box 802, 3000, Leuven, Belgium
| | - Yeranddy A Alpizar
- Laboratory for Ion Channel Research, Department of Cellular and Molecular Medicine, KU Leuven, VIB Center for Brain & Disease Research, O&N1 Herestraat 49 - box 802, 3000, Leuven, Belgium
| | - Alicia Sanchez
- Laboratory for Ion Channel Research, Department of Cellular and Molecular Medicine, KU Leuven, VIB Center for Brain & Disease Research, O&N1 Herestraat 49 - box 802, 3000, Leuven, Belgium
| | - Alejandro López-Requena
- Laboratory for Ion Channel Research, Department of Cellular and Molecular Medicine, KU Leuven, VIB Center for Brain & Disease Research, O&N1 Herestraat 49 - box 802, 3000, Leuven, Belgium
| | - Thomas Voets
- Laboratory for Ion Channel Research, Department of Cellular and Molecular Medicine, KU Leuven, VIB Center for Brain & Disease Research, O&N1 Herestraat 49 - box 802, 3000, Leuven, Belgium
| | - Karel Talavera
- Laboratory for Ion Channel Research, Department of Cellular and Molecular Medicine, KU Leuven, VIB Center for Brain & Disease Research, O&N1 Herestraat 49 - box 802, 3000, Leuven, Belgium.
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Maqboul A, Elsadek B. Expression profiles of TRPV1, TRPV4, TLR4 and ERK1/2 in the dorsal root ganglionic neurons of a cancer-induced neuropathy rat model. PeerJ 2018; 6:e4622. [PMID: 29637027 PMCID: PMC5889703 DOI: 10.7717/peerj.4622] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 03/25/2018] [Indexed: 01/09/2023] Open
Abstract
Background The spread of tumors through neural routes is common in several types of cancer in which patients suffer from a moderate-to-severe neuropathy, neural damage and a distorted quality of life. Here we aim to examine the expression profiles of transient receptor potential vanilloid 1 (TRPV1) and of transient receptor potential vanilloid 4 (TRPV4), toll-like receptor 4 (TLR4) and extracellular signal-regulated kinase (ERK1/2), and to assess the possible therapeutic strategies through blockade of transient receptor potential (TRP) channels. Methods Cancer was induced within the sciatic nerves of male Copenhagen rats, and tissues from dorsal root ganglia (DRG) were collected and used for measurements of immunofluorescence and Western blotting. The TRPV1 antagonist capsazepine, the selective TRPV4 antagonist HC-067047 and the calcium ions inhibitor ruthenium red were used to treat thermal and/or mechanical hyperalgesia. Results Transient receptor potential vanilloid 1 showed a lower expression in DRGs on days 7 and 14. The expression of TRPV4, TLR4 and ERK1/2 showed an increase on day 3 then a decrease on days 7 and 14. TRPV1 and TLR4 as well as TRPV4 and ERK1/2 co-existed on the same neuronal cells. The neuropathic pain was reversed in dose-dependent manners by using the TRP antagonists and the calcium ions inhibitor. Conclusion The decreased expression of TRPV1 and TRPV4 is associated with high activation. The increased expression of TLR4 and ERK1/2 reveals earlier immune response and tumor progression, respectively, and their ultimate decrease is an indicator of nerve damage. We studied the possible role of TRPV1 and TRPV4 in transducing cancer-induced hyperalgesia. The possible treatment strategies of cancer-induced thermal and/or mechanical hyperalgesia using capsazepine, HC-067047 and ruthenium red are examined.
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Affiliation(s)
- Ahmad Maqboul
- Department of Anesthesiology and Operative Intensive Care Medicine, Charité Faculty of Medicine, Humboldt-Universität zu Berlin, Campus Mitte and Campus Virchow-Klinikum, Berlin, Germany.,Department of Biochemistry, College of Pharmacy, Al-Azhar University, Asyût, Egypt
| | - Bakheet Elsadek
- Department of Biochemistry, College of Pharmacy, Al-Azhar University, Asyût, Egypt
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Alpizar YA, Boonen B, Sanchez A, Jung C, López-Requena A, Naert R, Steelant B, Luyts K, Plata C, De Vooght V, Vanoirbeek JAJ, Meseguer VM, Voets T, Alvarez JL, Hellings PW, Hoet PHM, Nemery B, Valverde MA, Talavera K. TRPV4 activation triggers protective responses to bacterial lipopolysaccharides in airway epithelial cells. Nat Commun 2017; 8:1059. [PMID: 29057902 PMCID: PMC5651912 DOI: 10.1038/s41467-017-01201-3] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 08/29/2017] [Indexed: 12/19/2022] Open
Abstract
Lipopolysaccharides (LPS), the major components of the wall of gram-negative bacteria, trigger powerful defensive responses in the airways via mechanisms thought to rely solely on the Toll-like receptor 4 (TLR4) immune pathway. Here we show that airway epithelial cells display an increase in intracellular Ca2+ concentration within seconds of LPS application. This response occurs in a TLR4-independent manner, via activation of the transient receptor potential vanilloid 4 cation channel (TRPV4). We found that TRPV4 mediates immediate LPS-induced increases in ciliary beat frequency and the production of bactericidal nitric oxide. Upon LPS challenge TRPV4-deficient mice display exacerbated ventilatory changes and recruitment of polymorphonuclear leukocytes into the airways. We conclude that LPS-induced activation of TRPV4 triggers signaling mechanisms that operate faster and independently from the canonical TLR4 immune pathway, leading to immediate protective responses such as direct antimicrobial action, increase in airway clearance, and the regulation of the inflammatory innate immune reaction. LPS is a major component of gram-negative bacterial cell walls, and triggers immune responses in airway epithelium by activating TLR4. Here the authors show that LPS also activates TRPV4, thereby inducing fast defense responses such as nitric oxide production and increased ciliary beating in mice.
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Affiliation(s)
- Yeranddy A Alpizar
- Department of Cellular and Molecular Medicine, Laboratory for Ion Channel Research, KU Leuven, Leuven, 3000, Belgium.,VIB Center for Brain & Disease Research, 3000, Leuven, Belgium
| | - Brett Boonen
- Department of Cellular and Molecular Medicine, Laboratory for Ion Channel Research, KU Leuven, Leuven, 3000, Belgium.,VIB Center for Brain & Disease Research, 3000, Leuven, Belgium
| | - Alicia Sanchez
- Department of Cellular and Molecular Medicine, Laboratory for Ion Channel Research, KU Leuven, Leuven, 3000, Belgium.,VIB Center for Brain & Disease Research, 3000, Leuven, Belgium
| | - Carole Jung
- Department of Experimental and Health Sciences, Laboratory of Molecular Physiology and Channelopathies, Universitat Pompeu Fabra, Barcelona, 08003, Spain
| | - Alejandro López-Requena
- Department of Cellular and Molecular Medicine, Laboratory for Ion Channel Research, KU Leuven, Leuven, 3000, Belgium.,VIB Center for Brain & Disease Research, 3000, Leuven, Belgium
| | - Robbe Naert
- Department of Cellular and Molecular Medicine, Laboratory for Ion Channel Research, KU Leuven, Leuven, 3000, Belgium.,VIB Center for Brain & Disease Research, 3000, Leuven, Belgium
| | - Brecht Steelant
- Department of Microbiology and Immunology, Laboratory of Clinical Immunology, KU Leuven, Leuven, 3000, Belgium
| | - Katrien Luyts
- Department of Public Health and Care, Laboratory of Environment and Health, KU Leuven, Leuven, 3000, Belgium
| | - Cristina Plata
- Department of Experimental and Health Sciences, Laboratory of Molecular Physiology and Channelopathies, Universitat Pompeu Fabra, Barcelona, 08003, Spain
| | - Vanessa De Vooght
- Department of Public Health and Care, Laboratory of Environment and Health, KU Leuven, Leuven, 3000, Belgium
| | - Jeroen A J Vanoirbeek
- Department of Public Health and Care, Laboratory of Environment and Health, KU Leuven, Leuven, 3000, Belgium
| | - Victor M Meseguer
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, E-03550, San Juan de Alicante, Spain
| | - Thomas Voets
- Department of Cellular and Molecular Medicine, Laboratory for Ion Channel Research, KU Leuven, Leuven, 3000, Belgium.,VIB Center for Brain & Disease Research, 3000, Leuven, Belgium
| | - Julio L Alvarez
- Department of Cellular and Molecular Medicine, Laboratory for Ion Channel Research, KU Leuven, Leuven, 3000, Belgium
| | - Peter W Hellings
- Department of Microbiology and Immunology, Laboratory of Clinical Immunology, KU Leuven, Leuven, 3000, Belgium.,Department of Oto-Rhino-Laryngology, Upper Airways Research Laboratory, Ghent University, Ghent, 9000, Belgium
| | - Peter H M Hoet
- Department of Public Health and Care, Laboratory of Environment and Health, KU Leuven, Leuven, 3000, Belgium
| | - Benoit Nemery
- Department of Public Health and Care, Laboratory of Environment and Health, KU Leuven, Leuven, 3000, Belgium
| | - Miguel A Valverde
- Department of Experimental and Health Sciences, Laboratory of Molecular Physiology and Channelopathies, Universitat Pompeu Fabra, Barcelona, 08003, Spain
| | - Karel Talavera
- Department of Cellular and Molecular Medicine, Laboratory for Ion Channel Research, KU Leuven, Leuven, 3000, Belgium. .,VIB Center for Brain & Disease Research, 3000, Leuven, Belgium.
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Dieb W, Moreau N, Chemla I, Descroix V, Boucher Y. Neuropathic pain in the orofacial region: The role of pain history. A retrospective study. JOURNAL OF STOMATOLOGY, ORAL AND MAXILLOFACIAL SURGERY 2017; 118:147-150. [PMID: 28365394 DOI: 10.1016/j.jormas.2017.03.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 02/07/2017] [Accepted: 03/16/2017] [Indexed: 12/18/2022]
Abstract
INTRODUCTION Orofacial neuropathic pain is often difficult to treat, mostly because of still unclear underlying mechanisms. The occurrence of such neuropathic pain varies depending on different factors, of which preexisting preoperative pain seems to be of high importance. The aim of this study was thus to test the hypothesis that prior history of pain could indeed be considered a risk factor for the development of orofacial neuropathic pain in the same region. METHODS The study was performed in the dental department of the Groupe Hospitalier Pitié-Salpêtrière (GHPS) in Paris, France. We investigated the presence of prior inflammatory pain before development of orofacial neuropathic pain in 56 patients. For each patient file, the following items were collected: age, gender; medical history; diagnosis; description of the pain (at time of consultation); presence or absence of prior dental treatment; date and type of dental treatment received. RESULTS 41 patients (73%) of orofacial neuropathic pain patients had a history of pain compatible with an inflammatory condition; 4% (n=2) did not report any prior pain and 23% (n=13) could not remember. Among the patients with documented history of pain prior to neuropathy, 88% (n=36) received surgical treatment; 61%, (n=25) endodontic treatment and 22%, (n=9) restorative treatment. All eventually received endodontic treatment or tooth extraction. These dental treatments are compatible with the hypothesis of prior inflammatory pain in these patients. CONCLUSION These results support the hypothesis that prior inflammatory pain could favor the development of orofacial neuropathic pain. Prevention and treatment of inflammatory trigeminal pain may therefore play a key role in preventing future neuropathic pain development.
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Affiliation(s)
- W Dieb
- UFR d'Odontologie, Université Paris Diderot, Hôpital Pitié Salpêtrière, Paris, France
| | - N Moreau
- UFR d'Odontologie, Université Paris Descartes, Hôpital Bretonneau, Paris, France
| | - I Chemla
- UFR d'Odontologie, Université Paris Diderot, Hôpital Pitié Salpêtrière, Paris, France
| | - V Descroix
- UFR d'Odontologie, Université Paris Diderot, Hôpital Pitié Salpêtrière, Paris, France
| | - Y Boucher
- UFR d'Odontologie, Université Paris Diderot, Hôpital Pitié Salpêtrière, Paris, France.
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Martinho FC, Leite FRM, Nóbrega LMM, Endo MS, Nascimento GG, Darveau RP, Gomes BPFA. Comparison of Fusobacterium nucleatum and Porphyromonas gingivalis Lipopolysaccharides Clinically Isolated from Root Canal Infection in the Induction of Pro-Inflammatory Cytokines Secretion. Braz Dent J 2017; 27:202-7. [PMID: 27058385 DOI: 10.1590/0103-6440201600572] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 03/08/2016] [Indexed: 12/23/2022] Open
Abstract
The aim of this study was to compare the biological activity of lipopolysaccharides (LPS) purified from Fusobacterium nucleatum and Porphyromonas gingivalis strains, both isolated from primary endodontic infection (PEI) in the levels of IL-1β and TNF-α released by macrophage cells. Moreover, LPS was purified from F. nucleatum and P. gingivalis American Type Collection (ATCC) and its biological activity was compared to respectively clinical isolates strains. F. nucleatum and P. gingivalis strains clinically isolated from PEI had their identification confirmed by sequencing the 16S rRNA gene. LPS from F. nucleatum and P. gingivalis and their respective ATCC strains were extracted by using Tri-reagent method. Macrophages (Raw 264.7) were stimulated with LPS at 100 ng/mL for 4, 8 and 12 h. Secretion of IL-1 β and TNF-α was also determined. Paired t-test, repeated measures ANOVA and one-way ANOVA were employed. All LPS induced significant production of IL-1β and TNF-α, with the former being secreted at higher levels than the latter in all time-points. F. nucleatum induced a higher expression of both cytokines compared to P. gingivalis (p<0.05). No differences were observed between clinical and ATCC strains, as both presented the same potential to induce pro-inflammatory response. It was concluded that F. nucleatum and P. gingivalis LPS presented different patterns of activation against macrophages as seen by the IL-1β and TNF-α production, which may contribute to the immunopathogenesis of apical periodontitis. Moreover, clinical and ATCC strains grown under the same in vitro environment conditions presented similar biological activity.
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Affiliation(s)
- Frederico C Martinho
- Department of Restorative Dentistry, Endodontics Division, São José dos Campos Dental School, Universidade Estadual de São Paulo, São José dos Campos, SP, Brazil
| | - Fábio R M Leite
- Postgraduate Program in Dentistry, Dental School, Universidade Federal de Pelotas, RS, Brazil, Brazil
| | - Letícia M M Nóbrega
- Department of Restorative Dentistry, Endodontics Division, Piracicaba Dental School, Universidade Estadual de Campinas, Piracicaba, SP, Brazil
| | - Marcos S Endo
- Department of Restorative Dentistry, Endodontics Division, Piracicaba Dental School, Universidade Estadual de Campinas, Piracicaba, SP, Brazil
| | - Gustavo G Nascimento
- Postgraduate Program in Dentistry, Dental School, Universidade Federal de Pelotas, RS, Brazil, Brazil
| | - Richard P Darveau
- Department of Periodontics and Oral Biology, University of Washington, Seattle, WA, USA
| | - Brenda P F A Gomes
- Department of Restorative Dentistry, Endodontics Division, Piracicaba Dental School, Universidade Estadual de Campinas, Piracicaba, SP, Brazil
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Yang NJ, Chiu IM. Bacterial Signaling to the Nervous System through Toxins and Metabolites. J Mol Biol 2017; 429:587-605. [PMID: 28065740 PMCID: PMC5325782 DOI: 10.1016/j.jmb.2016.12.023] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 12/21/2016] [Accepted: 12/29/2016] [Indexed: 12/31/2022]
Abstract
Mammalian hosts interface intimately with commensal and pathogenic bacteria. It is increasingly clear that molecular interactions between the nervous system and microbes contribute to health and disease. Both commensal and pathogenic bacteria are capable of producing molecules that act on neurons and affect essential aspects of host physiology. Here we highlight several classes of physiologically important molecular interactions that occur between bacteria and the nervous system. First, clostridial neurotoxins block neurotransmission to or from neurons by targeting the SNARE complex, causing the characteristic paralyses of botulism and tetanus during bacterial infection. Second, peripheral sensory neurons-olfactory chemosensory neurons and nociceptor sensory neurons-detect bacterial toxins, formyl peptides, and lipopolysaccharides through distinct molecular mechanisms to elicit smell and pain. Bacteria also damage the central nervous system through toxins that target the brain during infection. Finally, the gut microbiota produces molecules that act on enteric neurons to influence gastrointestinal motility, and metabolites that stimulate the "gut-brain axis" to alter neural circuits, autonomic function, and higher-order brain function and behavior. Furthering the mechanistic and molecular understanding of how bacteria affect the nervous system may uncover potential strategies for modulating neural function and treating neurological diseases.
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Affiliation(s)
- Nicole J Yang
- Department of Microbiology and Immunobiology, Division of Immunology, Harvard Medical School, Boston, MA 02115, USA
| | - Isaac M Chiu
- Department of Microbiology and Immunobiology, Division of Immunology, Harvard Medical School, Boston, MA 02115, USA.
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Guerrero ATG, Pinto LG, Cunha FQ, Ferreira SH, Alves-Filho JC, Verri WA, Cunha TM. Mechanisms underlying the hyperalgesic responses triggered by joint activation of TLR4. Pharmacol Rep 2016; 68:1293-1300. [PMID: 27689757 DOI: 10.1016/j.pharep.2016.08.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 08/15/2016] [Accepted: 08/23/2016] [Indexed: 01/04/2023]
Abstract
BACKGROUND Toll-like receptors (TLRs) including TLR4 and their signal pathways contribute to the pathogenesis of arthritis. Herein, we evaluated the mechanisms underlying the hyperalgesic response caused by TLR4 activation in the tibio-tarsal joint in mice. METHODS Joint inflammatory hyperalgesia was induced by intra-articular (ia) injection of LPS (lipopolysaccharide- TLR4 agonist) in C57BL/6, TLR4, TLR2, MyD88, TRIF, TNFR1/2 and IL-1R1 knockout (-/-) mice. Joint hyperalgesia was evaluated using an electronic von Frey. Neutrophil recruitment was assessed by MPO activity. Joint levels of cytokines were measured by ELISA. RESULTS Firstly, it was shown that LPS injected into the joints causes a dose- and time-dependent reduction in the mechanical nociceptive threshold. The TLR4 activation in the joint triggers mechanical hyperalgesia and neutrophil migration, which was abolished in TLR4 -/- and MyD88-/-, but not in TLR2-/- and TRIF-/- mice. Besides, joint administration of LPS increased the release of TNF-α, IL-1β, and KC/CXCL1, which were reduced in TLR4-/- and MyD88-/-, but not in TRIF-/- mice. In agreement, the LPS-induced joint nociceptive effect was decreased in TNFR1/2-/- and IL-1R1-/- mice or in mice pre-treated with a CXCR1/2 selective antagonist (DF2156A). CONCLUSIONS These results suggest that TLR4 activation in the joint produces articular hyperalgesia via MyD88 signaling pathway. Moreover, this pathway is involved in the cascade of events of articular hyperalgesia through mechanisms dependent on cytokines and chemokines production. Thus, TLR4/MyD88 signaling pathway inhibitors might be useful for the treatment of inflammatory joint pain.
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Affiliation(s)
- Ana T G Guerrero
- Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Avenida Bandeirantes, 3900, 14049-900 Ribeirão Preto, São Paulo, Brazil; Fundação Oswaldo Cruz-FIOCRUZ Mato Grosso do Sul, Rua Gabriel Abrão 92, 79081-746 Campo Grande, Mato Grosso do Sul, Brazil.
| | - Larissa G Pinto
- Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Avenida Bandeirantes, 3900, 14049-900 Ribeirão Preto, São Paulo, Brazil.
| | - Fernando Q Cunha
- Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Avenida Bandeirantes, 3900, 14049-900 Ribeirão Preto, São Paulo, Brazil.
| | - Sérgio H Ferreira
- Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Avenida Bandeirantes, 3900, 14049-900 Ribeirão Preto, São Paulo, Brazil.
| | - Jose C Alves-Filho
- Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Avenida Bandeirantes, 3900, 14049-900 Ribeirão Preto, São Paulo, Brazil.
| | - Waldiceu A Verri
- Departamento de Patologia, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Paraná, Rod. Celso Garcia Cid Km380 PR445, 86057-970 Londrina, Paraná, Brazil.
| | - Thiago M Cunha
- Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Avenida Bandeirantes, 3900, 14049-900 Ribeirão Preto, São Paulo, Brazil.
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Allais L, De Smet R, Verschuere S, Talavera K, Cuvelier CA, Maes T. Transient Receptor Potential Channels in Intestinal Inflammation: What Is the Impact of Cigarette Smoking? Pathobiology 2016; 84:1-15. [DOI: 10.1159/000446568] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 05/02/2016] [Indexed: 11/19/2022] Open
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Hargreaves KM, Ruparel S. Role of Oxidized Lipids and TRP Channels in Orofacial Pain and Inflammation. J Dent Res 2016; 95:1117-23. [PMID: 27307050 DOI: 10.1177/0022034516653751] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Acute or chronic inflammation comprises a highly prevalent type of orofacial pain and is mediated by the generation of endogenous agonists that activate numerous receptors expressed on terminals of trigeminal (TG) nociceptive afferent neurons. One such studied receptor is transient receptor potential vanilloid subtype 1 (TRPV1). TRPV1 is a ligand-gated cation channel that is expressed on a major subclass of nociceptors and is found in many orofacial tissues, including dental pulp. Antagonists to TRPV1 reveal an important role for this channel in mediating hypersensitivity in preclinical models of inflammatory or neuropathic pain. Recent studies have demonstrated that endogenous TRPV1 agonists are generated by oxidation of omega-6 polyunsaturated fatty acids, including both linoleic acid and arachidonic acid. A major mechanism triggering the release of oxidative linoleic acid metabolites (OLAMs) and oxidative arachidonic acid metabolites (OAAMs) is the action of oxidative enzymes. Oxidative enzymes such as cytochrome P450 isozymes are rapidly upregulated in TG neurons after orofacial inflammation and increase the capacity of TG neurons to generate OLAMs. Cytochrome P450 isozymes are also increased in immune cells in irreversibly inflamed human dental pulp, and extracts of this tissue have significantly increased capacity to generate OLAMs. Together, these studies point to a novel pain mechanism involving the enzymatic generation of endogenous OLAM and OAAM agonists of TRPV1. This finding provides a rationale for an entirely new class of analgesics by inhibition of oxidative enzyme activity.
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Affiliation(s)
- K M Hargreaves
- Department of Endodontics, University of Texas Health Science Center at San Antonio, TX, USA
| | - S Ruparel
- Department of Endodontics, University of Texas Health Science Center at San Antonio, TX, USA
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Abstract
Itch is a unique sensation associated with the scratch reflex. Although the scratch reflex plays a protective role in daily life by removing irritants, chronic itch remains a clinical challenge. Despite urgent clinical need, itch has received relatively little research attention and its mechanisms have remained poorly understood until recently. The goal of the present review is to summarize our current understanding of the mechanisms of acute as well as chronic itch and classifications of the primary itch populations in relationship to transient receptor potential (Trp) channels, which play pivotal roles in multiple somatosensations. The convergent involvement of Trp channels in diverse itch signaling pathways suggests that Trp channels may serve as promising targets for chronic itch treatments.
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Affiliation(s)
- Shuohao Sun
- The Solomon H. Snyder Department of Neuroscience, Center for Sensory Biology, Johns Hopkins University, School of Medicine, Baltimore, MD, 21205, USA
| | - Xinzhong Dong
- The Solomon H. Snyder Department of Neuroscience, Center for Sensory Biology, Johns Hopkins University, School of Medicine, Baltimore, MD, 21205, USA.
- Howard Hughes Medical Institute, Johns Hopkins University, School of Medicine, Baltimore, MD, 21205, USA.
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Lim JY, Choi SI, Choi G, Hwang SW. Atypical sensors for direct and rapid neuronal detection of bacterial pathogens. Mol Brain 2016; 9:26. [PMID: 26960533 PMCID: PMC4784462 DOI: 10.1186/s13041-016-0202-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 02/23/2016] [Indexed: 12/16/2022] Open
Abstract
Bacterial infection can threaten the normal biological functions of a host, often leading to a disease. Hosts have developed complex immune systems to cope with the danger. Preceding the elimination of pathogens, selective recognition of the non-self invaders is necessary. At the forefront of the body’s defenses are the innate immune cells, which are equipped with particular sensor molecules that can detect common exterior patterns of invading pathogens and their secreting toxins as well as with phagocytic machinery. Inflammatory mediators and cytokines released from these innate immune cells and infected tissues can boost the inflammatory cascade and further recruit adaptive immune cells to maximize the elimination and resolution. The nervous system also seems to interact with this process, mostly known to be affected by the inflammatory mediators through the binding of neuronal receptors, consequently activating neural circuits that tune the local and systemic inflammatory states. Recent research has suggested new contact points: direct interactions of sensory neurons with pathogens. Latest findings demonstrated that the sensory neurons not only share pattern recognition mechanisms with innate immune cells, but also utilize endogenous and exogenous electrogenic components for bacterial pathogen detection, by which the electrical firing prompts faster information flow than what could be achieved when the immune system is solely involved. As a result, rapid pain generation and active accommodation of the immune status occur. Here we introduced the sensory neuron-specific detector molecules for directly responding to bacterial pathogens and their signaling mechanisms. We also discussed extended issues that need to be explored in the future.
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Affiliation(s)
- Ji Yeon Lim
- Department of Biomedical Sciences, Korea University College of Medicine, Seoul, 136-705, Korea. .,Department of Physiology, Korea University College of Medicine, Seoul, 136-705, Korea.
| | - Seung-In Choi
- Department of Biomedical Sciences, Korea University College of Medicine, Seoul, 136-705, Korea. .,Department of Physiology, Korea University College of Medicine, Seoul, 136-705, Korea.
| | - Geunyeol Choi
- Department of Biomedical Sciences, Korea University College of Medicine, Seoul, 136-705, Korea. .,Department of Physiology, Korea University College of Medicine, Seoul, 136-705, Korea.
| | - Sun Wook Hwang
- Department of Biomedical Sciences, Korea University College of Medicine, Seoul, 136-705, Korea. .,Department of Physiology, Korea University College of Medicine, Seoul, 136-705, Korea.
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Helley M, Abate W, Jackson S, Bennett J, Thompson S. The expression of Toll-like receptor 4, 7 and co-receptors in neurochemical sub-populations of rat trigeminal ganglion sensory neurons. Neuroscience 2015; 310:686-98. [DOI: 10.1016/j.neuroscience.2015.09.069] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 09/03/2015] [Accepted: 09/25/2015] [Indexed: 12/12/2022]
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The Anti-Inflammatory Effect of Human Telomerase-Derived Peptide on P. gingivalis Lipopolysaccharide-Induced Inflammatory Cytokine Production and Its Mechanism in Human Dental Pulp Cells. Mediators Inflamm 2015; 2015:385127. [PMID: 26604431 PMCID: PMC4641190 DOI: 10.1155/2015/385127] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 10/09/2015] [Accepted: 10/13/2015] [Indexed: 11/18/2022] Open
Abstract
Porphyromonas gingivalis is considered with inducing pulpal inflammation and has lipopolysaccharide (LPS) as an inflammatory stimulator. GV1001 peptide has anticancer and anti-inflammation activity due to inhibiting activation of signaling molecules after penetration into the various types of cells. Therefore, this study examined inhibitory effect of GV1001 on dental pulp cells (hDPCs) stimulated by P. gingivalis LPS. The intracellular distribution of GV1001 was analyzed by confocal microscopy. Real-time RT-PCR was performed to determine the expression levels of TNF-α and IL-6 cytokines. The role of signaling by MAP kinases (ERK and p38) was explored using Western blot analysis. The effect of GV1001 peptide on hDPCs viability was measured by MTT assay. GV1001 was predominantly located in hDPC cytoplasm. The peptide inhibited P. gingivalis LPS-induced TNF-α and IL-6 production in hDPCs without significant cytotoxicity. Furthermore, GV1001 treatment markedly inhibited the phosphorylation of MAP kinases (ERK and p38) in LPS-stimulated hDPCs. GV1001 may prevent P. gingivalis LPS-induced inflammation of apical tissue. Also, these findings provide mechanistic insight into how GV1001 peptide causes anti-inflammatory actions in LPS-stimulated pulpitis without significantly affecting cell viability.
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Luo J, Feng J, Liu S, Walters ET, Hu H. Molecular and cellular mechanisms that initiate pain and itch. Cell Mol Life Sci 2015; 72:3201-23. [PMID: 25894692 PMCID: PMC4534341 DOI: 10.1007/s00018-015-1904-4] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 03/20/2015] [Accepted: 04/07/2015] [Indexed: 12/17/2022]
Abstract
Somatosensory neurons mediate our sense of touch. They are critically involved in transducing pain and itch sensations under physiological and pathological conditions, along with other skin-resident cells. Tissue damage and inflammation can produce a localized or systemic sensitization of our senses of pain and itch, which can facilitate our detection of threats in the environment. Although acute pain and itch protect us from further damage, persistent pain and itch are debilitating. Recent exciting discoveries have significantly advanced our knowledge of the roles of membrane-bound G protein-coupled receptors and ion channels in the encoding of information leading to pain and itch sensations. This review focuses on molecular and cellular events that are important in early stages of the biological processing that culminates in our senses of pain and itch.
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Affiliation(s)
- Jialie Luo
- Department of Anesthesiology, The Center for the Study of Itch, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO, 63110, USA
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Lin JJ, Du Y, Cai WK, Kuang R, Chang T, Zhang Z, Yang YX, Sun C, Li ZY, Kuang F. Toll-like receptor 4 signaling in neurons of trigeminal ganglion contributes to nociception induced by acute pulpitis in rats. Sci Rep 2015. [PMID: 26224622 PMCID: PMC4519790 DOI: 10.1038/srep12549] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Pain caused by acute pulpitis (AP) is a common symptom in clinical settings. However, its underlying mechanisms have largely remained unknown. Using AP model, we demonstrated that dental injury caused severe pulp inflammation with up-regulated serum IL-1β. Assessment from head-withdrawal reflex thresholds (HWTs) and open-field test demonstrated nociceptive response at 1 day post injury. A consistent up-regulation of Toll-like receptor 4 (TLR4) in the trigeminal ganglion (TG) ipsilateral to the injured pulp was found; and downstream signaling components of TLR4, including MyD88, TRIF and NF-κB, and cytokines such as TNF-α and IL-1β, were also increased. Retrograde labeling indicated that most TLR4 positve neuron in the TG innnervated the pulp and TLR4 immunoreactivity was mainly in the medium and small neurons. Double labeling showed that the TLR4 expressing neurons in the ipsilateral TG were TRPV1 and CGRP positive, but IB4 negative. Furthermore, blocking TLR4 by eritoran (TLR4 antagonist) in TGs of the AP model significantly down-regulated MyD88, TRIF, NF-κB, TNF-α and IL-1β production and behavior of nociceptive response. Our findings suggest that TLR4 signaling in TG cells, particularly the peptidergic TRPV1 neurons, plays a key role in AP-induced nociception, and indicate that TLR4 signaling could be a potential therapeutic target for orofacial pain.
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Affiliation(s)
- Jia-Ji Lin
- 1] Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710004, China [2] Department of Neurobiology and Collaborative Innovation Center for Brain Science, School of Basic Medicine, The Fourth Military Medical University, Xi'an, 710032, China
| | - Yi Du
- 1] State Key Laboratory of Military Stomatology, Department of Operative Dentistry and Endodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, 710032,China [2] Department of Endodontics, Jinan Stomatological Hospital, Jinan, 250001, China
| | - Wen-Ke Cai
- 1] Department of Cardio-Thoracic Surgery, Kunming General Hospital of Chengdu Military Region, Kunming, 650000, China [2] Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710004, China
| | - Rong Kuang
- State Key Laboratory of Military Stomatology, Department of Operative Dentistry and Endodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, 710032,China
| | - Ting Chang
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710004, China
| | - Zhuo Zhang
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710004, China
| | - Yong-Xiang Yang
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710004, China
| | - Chao Sun
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710004, China
| | - Zhu-Yi Li
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710004, China
| | - Fang Kuang
- Department of Neurobiology and Collaborative Innovation Center for Brain Science, School of Basic Medicine, The Fourth Military Medical University, Xi'an, 710032, China
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Cardoso FGR, Ferreira NS, Martinho FC, Nascimento GG, Manhães LRC, Rocco MA, Carvalho CAT, Valera MC. Correlation between Volume of Apical Periodontitis Determined by Cone-beam Computed Tomography Analysis and Endotoxin Levels Found in Primary Root Canal Infection. J Endod 2015; 41:1015-9. [PMID: 25935504 DOI: 10.1016/j.joen.2015.02.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 12/09/2014] [Accepted: 02/04/2015] [Indexed: 10/23/2022]
Abstract
INTRODUCTION This clinical study was conducted to correlate the levels of endotoxins and bacterial counts found in primary endodontic infection with the volume of periapical bone destruction determined by cone-beam computed tomography (CBCT) analysis. Moreover, the levels of bacteria and endotoxins were correlated with the development of clinical features. METHODS Twenty-four root canals with primary endodontic disease and apical periodontitis were selected. Clinical features such as pain on palpation, pain on percussion, and previous episode of pain were recorded. The volume (cubic millimeters) of periapical bone destruction was determined by CBCT analysis. Endotoxins and bacterial samplings were collected by using sterile/apyrogenic paper points. Endotoxins were quantified by using limulus amebocyte lysate assay (KQCL test), and bacterial count (colony-forming units [CFU]/mL) was determined by using anaerobic culture techniques. Data were analyzed by Pearson correlation and multiple logistic regression (P < .05). RESULTS Endotoxins and bacteria were detected in 100% of the root canal samples (24 of 24), with median values of 10.92 endotoxin units (EU)/mL (1.75-128 EU/mL) and 7.5 × 10(5) CFU/mL (3.20 × 10(5)-8.16 × 10(6) CFU/mL), respectively. The median volume of bone destruction determined by CBCT analysis was 100 mm(3) (10-450 mm(3)). The multiple regression analysis revealed a positive correlation between higher levels of endotoxins present in root canal infection and larger volume of bone destruction (P < .05). Moreover, higher levels of endotoxins were also correlated with the presence of previous pain (P < .05). CONCLUSIONS Our findings revealed that the levels of endotoxins found in root canal infection are related to the volume of periapical bone destruction determined by CBCT analysis. Moreover, the levels of endotoxin are related to the presence of previous pain.
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Affiliation(s)
- Flávia G R Cardoso
- Department of Restorative Dentistry, Endodontic Division, São José dos Campos Institute of Science Technology, Universidade Estadual Paulista (UNESP), São José dos Campos, São Paulo, Brazil
| | - Nádia S Ferreira
- Department of Restorative Dentistry, Endodontic Division, São José dos Campos Institute of Science Technology, Universidade Estadual Paulista (UNESP), São José dos Campos, São Paulo, Brazil
| | - Frederico C Martinho
- Department of Restorative Dentistry, Endodontic Division, São José dos Campos Institute of Science Technology, Universidade Estadual Paulista (UNESP), São José dos Campos, São Paulo, Brazil
| | - Gustavo G Nascimento
- Department of Semiology, Federal University of Pelotas, School of Dentistry, Pelotas, Rio Grande do Sul, Brazil
| | - Luiz R C Manhães
- Department of Radiology, São José dos Campos Institute of Science Technology, Universidade Estadual Paulista (UNESP), São José dos Campos, São Paulo, Brazil
| | - Marco A Rocco
- Department of Radiology, São José dos Campos Institute of Science Technology, Universidade Estadual Paulista (UNESP), São José dos Campos, São Paulo, Brazil
| | - Cláudio A T Carvalho
- Department of Restorative Dentistry, Endodontic Division, São José dos Campos Institute of Science Technology, Universidade Estadual Paulista (UNESP), São José dos Campos, São Paulo, Brazil
| | - Marcia C Valera
- Department of Restorative Dentistry, Endodontic Division, São José dos Campos Institute of Science Technology, Universidade Estadual Paulista (UNESP), São José dos Campos, São Paulo, Brazil.
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Calzetta L, Luongo L, Cazzola M, Page C, Rogliani P, Facciolo F, Maione S, Capuano A, Rinaldi B, Matera MG. Contribution of sensory nerves to LPS-induced hyperresponsiveness of human isolated bronchi. Life Sci 2015; 131:44-50. [PMID: 25914087 DOI: 10.1016/j.lfs.2015.03.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Revised: 03/11/2015] [Accepted: 03/29/2015] [Indexed: 10/23/2022]
Abstract
AIMS Bacterial lipopolysaccharide (LPS) can induce bronchial hyperresponsiveness (BHR), but the underlying mechanisms remain to be determined. Here, the possible contribution of sensory nerves to LPS-induced BHR was examined in human isolated bronchi to pharmacologically identify the mechanisms underlying this phenomenon. MAIN METHODS Human isolated bronchial tone was induced by electrical field stimulation (EFS). The responses of airways to LPS, with or without capsaicin desensitization or thiorphan treatment were studied and the transient receptor potential vanilloid type 1 (TRPV1) expression was assessed. We performed similar experiments in the presence of a TRPV1 or a neurokinin (NK) 2 receptor antagonist using SB366791 and GR159897, respectively. KEY FINDINGS LPS increased (≃2.3-fold, P<0.001) the contraction induced by EFS, compared to control tissues. Acute administration of capsaicin enhanced (≃2.3-fold, P<0.001) the EFS-mediated contraction, but did not potentiate the effect of LPS. Thiorphan increased (≃1.3-fold, P<0.05) the contractile response of LPS treated tissues and, at lower frequencies, it enhanced (≃1.7-fold, P<0.001) the capsaicin-induced contraction. In capsaicin-desensitized bronchi, LPS did not modify (P>0.05) the EFS contractile response, nor after treatment with thiorphan. Capsaicin desensitization reduced (≃0.4-fold, P<0.001) the LPS-induced BHR. SB366791 and GR159897 prevented the LPS-induced BHR and the release of NKA. LPS increased (+85.3±9.5%, P<0.01) the surface membrane expression of TRPV1 in parasympathetic ganglia. SIGNIFICANCE Our results demonstrate the involvement of capsaicin-sensitive sensory nerves and neutral endopeptidases in LPS-induced BHR of the human bronchi, associated with an upregulation of TRPV1 and release of NKA.
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Affiliation(s)
- Luigino Calzetta
- Department of Systems Medicine, University of Rome "Tor Vergata", Rome, Italy
| | - Livio Luongo
- Unit of Pharmacology, Department of Experimental Medicine, Second University of Naples, Naples, Italy
| | - Mario Cazzola
- Department of Systems Medicine, University of Rome "Tor Vergata", Rome, Italy.
| | - Clive Page
- The Sackler Institute of Pulmonary Pharmacology, Institute of Pharmaceutical Science, King's College London, London, UK
| | - Paola Rogliani
- Department of Systems Medicine, University of Rome "Tor Vergata", Rome, Italy
| | | | - Sabatino Maione
- Unit of Pharmacology, Department of Experimental Medicine, Second University of Naples, Naples, Italy
| | - Annalisa Capuano
- Unit of Pharmacology, Department of Experimental Medicine, Second University of Naples, Naples, Italy
| | - Barbara Rinaldi
- Unit of Pharmacology, Department of Experimental Medicine, Second University of Naples, Naples, Italy
| | - Maria Gabriella Matera
- Unit of Pharmacology, Department of Experimental Medicine, Second University of Naples, Naples, Italy
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Santoni G, Cardinali C, Morelli MB, Santoni M, Nabissi M, Amantini C. Danger- and pathogen-associated molecular patterns recognition by pattern-recognition receptors and ion channels of the transient receptor potential family triggers the inflammasome activation in immune cells and sensory neurons. J Neuroinflammation 2015; 12:21. [PMID: 25644504 PMCID: PMC4322456 DOI: 10.1186/s12974-015-0239-2] [Citation(s) in RCA: 111] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 01/07/2015] [Indexed: 02/08/2023] Open
Abstract
An increasing number of studies show that the activation of the innate immune system and inflammatory mechanisms play an important role in the pathogenesis of numerous diseases. The innate immune system is present in almost all multicellular organisms and its activation occurs in response to pathogens or tissue injury via pattern-recognition receptors (PRRs) that recognize pathogen-associated molecular patterns (PAMPs) or danger-associated molecular patterns (DAMPs). Intracellular pathways, linking immune and inflammatory response to ion channel expression and function, have been recently identified. Among ion channels, the transient receptor potential (TRP) channels are a major family of non-selective cation-permeable channels that function as polymodal cellular sensors involved in many physiological and pathological processes. In this review, we summarize current knowledge of interactions between immune cells and PRRs and ion channels of TRP families with PAMPs and DAMPs to provide new insights into the pathogenesis of inflammatory diseases. TRP channels have been found to interfere with innate immunity via both nuclear factor-kB and procaspase-1 activation to generate the mature caspase-1 that cleaves pro-interleukin-1β cytokine into the mature interleukin-1β. Sensory neurons are also adapted to recognize dangers by virtue of their sensitivity to intense mechanical, thermal and irritant chemical stimuli. As immune cells, they possess many of the same molecular recognition pathways for danger. Thus, they express PRRs including Toll-like receptors 3, 4, 7, and 9, and stimulation by Toll-like receptor ligands leads to induction of inward currents and sensitization in TRPs. In addition, the expression of inflammasomes in neurons and the involvement of TRPs in central nervous system diseases strongly support a role of TRPs in inflammasome-mediated neurodegenerative pathologies. This field is still at its beginning and further studies may be required. Overall, these studies highlight the therapeutic potential of targeting the inflammasomes in proinflammatory, autoinflammatory and metabolic disorders associated with undesirable activation of the inflammasome by using specific TRP antagonists, anti-human TRP monoclonal antibody or different molecules able to abrogate the TRP channel-mediated inflammatory signals.
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Affiliation(s)
- Giorgio Santoni
- School of Pharmacy, Section of Experimental Medicine, University of Camerino, Camerino, 62032, Italy.
| | - Claudio Cardinali
- School of Pharmacy, Section of Experimental Medicine, University of Camerino, Camerino, 62032, Italy. .,Department of Molecular Medicine, Sapienza University, Rome, 00185, Italy.
| | - Maria Beatrice Morelli
- School of Pharmacy, Section of Experimental Medicine, University of Camerino, Camerino, 62032, Italy. .,Department of Molecular Medicine, Sapienza University, Rome, 00185, Italy.
| | - Matteo Santoni
- Department of Medical Oncology, AOU Ospedali Riuniti, Polytechnic University of Marche, Ancona, 60126, Italy.
| | - Massimo Nabissi
- School of Pharmacy, Section of Experimental Medicine, University of Camerino, Camerino, 62032, Italy.
| | - Consuelo Amantini
- School of Biosciences and Veterinary Medicine, University of Camerino, Camerino, 62032, Italy.
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Alfonso Romero-Sandoval E, Sweitzer S. Nonneuronal central mechanisms of pain: glia and immune response. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 131:325-58. [PMID: 25744678 DOI: 10.1016/bs.pmbts.2014.11.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The role of central glial cells in the mechanisms underlying pain has been intensively studied in the last two decades. Most studies on glia and pain focused on the potential detrimental role of glial cells following noxious stimulus/insults manifested as an "activation" or a "reactive" state (increase in glial marker expression and production of proinflammatory/nociceptive molecules). Therefore, "activated" or "reactive" glial cells became a target for the future generation of drugs to treat chronic pain. Several glial modulators that reduce the activation of glial cells have shown great efficacy in multiple animal (rodents mostly) models of pain (acute, subacute, chronic, inflammatory, neuropathic, surgical, etc.). These encouraging findings inspired clinical trials that have been completed in the last 5 years. Unfortunately, all clinical trials with these glial modulators have failed to demonstrate efficacy for the treatment of pain. New lines of investigation and elegant experimental designs are shedding light on alternative glial functions, which demonstrate that "glial reactivity" is not necessarily deleterious in some pathological conditions. New strategies to validate findings through our current animal models are necessary to enhance the translational value of our preclinical studies. Also, more studies using human subjects would enhance our understanding of glial cells in the context of pain. This chapter explores the available literature to objectively ponder the potential role of glial cells in human pain conditions.
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Affiliation(s)
- E Alfonso Romero-Sandoval
- Department of Pharmaceutical and Administrative Sciences, Presbyterian College School of Pharmacy, Clinton, South Carolina, USA.
| | - Sarah Sweitzer
- Department of Pharmaceutical and Administrative Sciences, Presbyterian College School of Pharmacy, Clinton, South Carolina, USA
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Assas BM, Miyan JA, Pennock JL. Cross-talk between neural and immune receptors provides a potential mechanism of homeostatic regulation in the gut mucosa. Mucosal Immunol 2014; 7:1283-9. [PMID: 25183366 DOI: 10.1038/mi.2014.80] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 07/25/2014] [Indexed: 02/07/2023]
Abstract
The relationship between elements of the immune system and the nervous system in the presence of bacteria has been addressed recently. In particular, the sensory vanilloid receptor 1 (transient receptor potential cation channel subfamily V member 1 (TRPV1)) and the neuropeptide calcitonin gene-related peptide (CGRP) have been found to modulate cytokine response to lipopolysaccharide (LPS) independently of adaptive immunity. In this review we discuss mucosal homeostasis in the gastrointestinal tract where bacterial concentration is high. We propose that the Gram-negative bacterial receptor Toll-like receptor 4 (TLR4) can activate TRPV1 via intracellular signaling, and thereby induce the subsequent release of anti-inflammatory CGRP to maintain mucosal homeostasis.
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Affiliation(s)
- B M Assas
- 1] Faculty of Applied Medical Sciences, King Abdul Aziz University, Jeddah, Saudi Arabia [2] Faculty of Medicine and Human Sciences, University of Manchester, Manchester, UK
| | - J A Miyan
- Faculty of Life Sciences, University of Manchester, Manchester, UK
| | - J L Pennock
- Institute of Inflammation and Repair, Faculty of Medicine and Human Sciences, University of Manchester, Manchester, UK
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Kunda PE, Cavicchia JC, Acosta CG. Lipopolysaccharides and trophic factors regulate the LPS receptor complex in nodose and trigeminal neurons. Neuroscience 2014; 280:60-72. [PMID: 25218806 DOI: 10.1016/j.neuroscience.2014.08.053] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 08/12/2014] [Accepted: 08/26/2014] [Indexed: 12/21/2022]
Abstract
Binding of bacterial lipopolysaccharides (LPS) to toll-like receptor 4 (TLR4) triggers an innate immunoresponse associated with pain and inflammation. The expression, and to a greater extent the regulation of TLR4 and its auxiliary proteins (myeloid differentiation protein 1 (MD1), myeloid differentiation protein 2 (MD2) and cluster of differentiation 14 (CD14)), are both poorly understood in trigeminal and nodose neurons. We used a combination of Western blotting, semi-quantitative polymerase chain reaction (PCR), pharmacological manipulation and immunohistochemistry. The expression pattern and regulation by LPS and trophic factors of TLR4/MD2/CD14 and radioprotective protein of 105kDa (RP105)/MD1 were determined in neonatal trigeminal and nodose mice neurons. We found that all these proteins were expressed in both trigeminal and nodose neurons. The trophic factors Artemin and nerve growth factor (NGF) up-regulated MD2 and RP105 mRNA levels in trigeminal neurons. In nodose neurons the trophic factors brain-derived neurotrophic factor (BDNF), ciliary neurotrophic factor (CNTF) and leukemia inhibitory factor (LIF) up-regulated MD1 and RP105 mRNA levels. Also we observed that in both neuronal types LPS acutely (within 20 min) down-regulated CD14 and MD2 mRNAs. In addition, LPS increased significantly the proportion of trigeminal and nodose neurons expressing nociceptin/orphanin FQ in culture probably acting via TLR4/MD2. Although the exact mechanisms underlying the regulation by trophic factors and LPS require further elucidation, the findings of this study indicate that LPS acts through its archetypical receptor in trigeminal and nodose neurons.
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Affiliation(s)
- P E Kunda
- Instituto de Investigaciones en Ciencias de la Salud (INICSA), Facultad de Ciencias Medicas, Universidad Nacional de Córdoba, 5000 Córdoba, Argentina
| | - J C Cavicchia
- Instituto de Histología y Embriología de Mendoza (IHEM), Facultad de Medicina, Universidad Nacional de Cuyo, 5500 Mendoza, Argentina
| | - C G Acosta
- Instituto de Histología y Embriología de Mendoza (IHEM), Facultad de Medicina, Universidad Nacional de Cuyo, 5500 Mendoza, Argentina.
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Barr GA, Hunter DA. Interactions between glia, the immune system and pain processes during early development. Dev Psychobiol 2014; 56:1698-710. [PMID: 24910104 DOI: 10.1002/dev.21229] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 05/15/2014] [Indexed: 01/10/2023]
Abstract
Pain is a serious problem for infants and children and treatment options are limited. Moreover, infants born prematurely or hospitalized for illness likely have concurrent infection that activates the immune system. It is now recognized that the immune system in general and glia in particular influence neurotransmission and that the neural bases of pain are intimately connected to immune function. We know that injuries that induce pain activate immune function and suppressing the immune system alleviates pain. Despite this advance in our understanding, virtually nothing is known of the role that the immune system plays in pain processing in infants and children, even though pain is a serious clinical issue in pediatric medicine. This brief review summarizes the existing data on immune-neural interactions in infants, providing evidence for the immaturity of these interactions.
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Affiliation(s)
- Gordon A Barr
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, 19104.
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Blood-nerve barrier dysfunction contributes to the generation of neuropathic pain and allows targeting of injured nerves for pain relief. Pain 2014; 155:954-967. [DOI: 10.1016/j.pain.2014.01.026] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 01/15/2014] [Accepted: 01/28/2014] [Indexed: 01/09/2023]
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50
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Lipopolysaccharide differentially modulates expression of cytokines and cyclooxygenases in dorsal root ganglion cells via Toll-like receptor-4 dependent pathways. Neuroscience 2014; 267:241-51. [DOI: 10.1016/j.neuroscience.2014.02.041] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Revised: 02/24/2014] [Accepted: 02/25/2014] [Indexed: 11/19/2022]
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