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de Vasconcelos Gurgel BC, Peixe PG, Queiroz SIML, de Almeida Freitas R, de Aquino Martins ARL, Duarte PM. Comparison of immunoexpression of dendritic cells, mast cells and blood vessels in periodontal disease between adults and elderly. Clin Oral Investig 2023; 27:6823-6833. [PMID: 37814161 DOI: 10.1007/s00784-023-05297-4] [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: 02/08/2023] [Accepted: 09/27/2023] [Indexed: 10/11/2023]
Abstract
OBJECTIVE The aim of this study was to compare, in adults and elderly individuals, the immunoexpression of immature and mature dendritic cells (DCs), mast cells, and blood vessels in healthy and diseased gingival tissues. MATERIALS AND METHODS The expressions of immunohistochemical markers, including CD1a (immature dendritic cells), CD83 (mature dendritic cells), tryptase (mast cells) and CD34 (blood vessels), were analyzed in gingival biopsies from elderly (n = 27) and adult (n = 127) patients presenting health, gingivitis and periodontitis. Positive cells for each specimen and marker were counted. RESULTS There were no differences in the immunostaining of DCs, mast cells and the amount of blood vessels among gingival biopsies with health, gingivitis and periodontitis in adult and elderly subjects (p > 0.05). Immature DCs were more frequent in tissues with gingivitis and periodontitis in elderly patients, when compared to adults (p < 0.05). Furthermore, degranulated mast cell counts were higher, whereas the number of microvessels was lower in gingivitis in the elderly, when compared to adults (p < 0.05). CONCLUSIONS Diseased periodontal sites in the elderly present an overall significant overexpression of immature DCs and degranulated mast cells, in relation to those of adults. Furthermore, gingivitis in elderly is associated with decreased microvessel growth. These immunoinflammatory differences between elderly and adults may have implications in periodontal tissue breakdown in the late adulthood. Further studies should be performed to elucidate this hypothesis. CLINICAL RELEVANCE Understading the relationship between aging and changes in immune cells during periodontal inflammation may lead to therapeutic targets for the future management of periodontal diseases.
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Affiliation(s)
- Bruno Cesar de Vasconcelos Gurgel
- Department of Dentistry, Federal University of Rio Grande do Norte, 1787, Senador Salgado Filho Ave, Lagoa Nova, Natal, Rio Grande do Norte, CEP: 59056-000, Brazil.
| | - Patrícia Guerra Peixe
- Department of Dentistry, Federal University of Rio Grande do Norte, 1787, Senador Salgado Filho Ave, Lagoa Nova, Natal, Rio Grande do Norte, CEP: 59056-000, Brazil
| | - Salomão Israel Monteiro Lourenço Queiroz
- Department of Dentistry, Federal University of Rio Grande do Norte, 1787, Senador Salgado Filho Ave, Lagoa Nova, Natal, Rio Grande do Norte, CEP: 59056-000, Brazil
| | - Roseana de Almeida Freitas
- Department of Dentistry, Federal University of Rio Grande do Norte, 1787, Senador Salgado Filho Ave, Lagoa Nova, Natal, Rio Grande do Norte, CEP: 59056-000, Brazil
| | - Ana Rafaela Luz de Aquino Martins
- Department of Dentistry, Federal University of Rio Grande do Norte, 1787, Senador Salgado Filho Ave, Lagoa Nova, Natal, Rio Grande do Norte, CEP: 59056-000, Brazil
| | - Poliana Mendes Duarte
- Department of Periodontology, University of Florida, 1395 Center Dr, Gainesville, FL, 32610, USA
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Bailly C. The implication of the PD-1/PD-L1 checkpoint in chronic periodontitis suggests novel therapeutic opportunities with natural products. JAPANESE DENTAL SCIENCE REVIEW 2020; 56:90-96. [PMID: 32612718 PMCID: PMC7310691 DOI: 10.1016/j.jdsr.2020.04.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 04/13/2020] [Accepted: 04/21/2020] [Indexed: 12/12/2022] Open
Abstract
An analysis of the implication of the PD-1/PD-L1 immune checkpoint in periodontitis is provided with the objective to propose a novel therapeutic approach. An exhaustive survey of the literature has been performed to answer two questions: (1) Is there a role for PD-1 and/or PD-L1 in the development of periodontitis? (2) Which natural products interfere with the checkpoint activity and show activity against periodontitis? All online published information was collected and analyzed. The pathogenic bacteria Porphyromonas gingivalis, through its membrane-attached peptidoglycans, exploits the PD-1/PD-L1 checkpoint to evade immune response and to amplify the infection. Three anti-inflammatory natural products (and derivatives or plant extracts) active against periodontitis and able to interfere with the checkpoint were identified. Both curcumin and baicalin attenuate periodontitis and induce a down-regulation of PD-L1 in cells. The terpenoid saponin platycodin D inhibits the growth of P. gingivalis responsible for periodontitis and shows a rare capacity to induce the extracellular release of a soluble form of PD-L1, thereby restoring T cell activation. A potential PD-L1 shedding mechanism is discussed. The targeting of the PD-1/PD-L1 immune checkpoint could be considered a suitable approach to improve the treatment of chronic periodontitis. The plant natural products curcumin, baicalin and platycodin D should be further evaluated as PD-1/PD-L1 checkpoint modulators active against periodontitis.
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Iacov-Crăiţoiu MM, Crăiţoiu M. Clinical, histopathological and immunohistochemical behavior of peri-implant soft tissue. ROMANIAN JOURNAL OF MORPHOLOGY AND EMBRYOLOGY 2020; 61:121-128. [PMID: 32747902 PMCID: PMC7728131 DOI: 10.47162/rjme.61.1.13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The presence of foreign materials in the tissues, represented in the present study by the insertion of dental implants, creates artificial structures that can sometimes cause adverse consequences, which implies the obligation to perform a complex medical assessment before inserting dental implants. This assessment appreciates the quality of the tissue, depending on which the use of a certain type of biomaterial is indicated and focuses on a certain surgical technique. We assessed the clinical, histopathological (HP) and immunohistochemical (IHC) aspects of peri-implant soft tissue in patients who did not show mobility or imagistic signs of bone resorption, three months after implant insertion, some of them showing no inflammatory clinical signs. Immunohistochemically, on the sections of the peri-implant mucosa, we assessed the presence of mast cells, vascularization and the process of angiogenesis. Mast cells are key cells actively involved in the pathogenesis of peri-implant inflammation, having an immunomodulatory role. Vasodilation and angiogenesis, determined by the release of chemical mediators by degranulation of mast cells under the action of pathogens, induce tissue remodeling, ensuring the healing and formation of a tissue to form a barrier that effectively prevents the development of a bacterial biofilm. Thus, the control of the activity of these cells is important for the management of the local inflammatory process. The correlations between the clinical, HP and IHC behavior of the peri-implant soft tissue bring important information for the clinic, emphasizing the need to identify a therapeutic strategy to modulate mast cell activity, in order to prevent and treat peri-implant disease, to ensure osseointegration and longer survival of the dental implant.
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Affiliation(s)
- Monica Mihaela Iacov-Crăiţoiu
- Department of Prosthetic Dentistry, Faculty of Dental Medicine, University of Medicine and Pharmacy of Craiova, Romania;
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Mohajeri M, Kovanen PT, Bianconi V, Pirro M, Cicero AFG, Sahebkar A. Mast cell tryptase - Marker and maker of cardiovascular diseases. Pharmacol Ther 2019; 199:91-110. [PMID: 30877022 DOI: 10.1016/j.pharmthera.2019.03.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 03/01/2019] [Indexed: 12/14/2022]
Abstract
Mast cells are tissue-resident cells, which have been proposed to participate in various inflammatory diseases, among them the cardiovascular diseases (CVDs). For mast cells to be able to contribute to an inflammatory process, they need to be activated to exocytose their cytoplasmic secretory granules. The granules contain a vast array of highly bioactive effector molecules, the neutral protease tryptase being the most abundant protein among them. The released tryptase may act locally in the inflamed cardiac or vascular tissue, so contributing directly to the pathogenesis of CVDs. Moreover, a fraction of the released tryptase reaches the systemic circulation, thereby serving as a biomarker of mast cell activation. Actually, increased levels of circulating tryptase have been found to associate with CVDs. Here we review the biological relevance of the circulating tryptase as a biomarker of mast cell activity in CVDs, with special emphasis on the relationship between activation of mast cells in their tissue microenvironments and the pathophysiological pathways of CVDs. Based on the available in vitro and in vivo studies, we highlight the potential molecular mechanisms by which tryptase may contribute to the pathogenesis of CVDs. Finally, the synthetic and natural inhibitors of tryptase are reviewed for their potential utility as therapeutic agents in CVDs.
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Affiliation(s)
- Mohammad Mohajeri
- Department of Medical Biotechnology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | | | - Vanessa Bianconi
- Unit of Internal Medicine, Department of Medicine, University of Perugia, Perugia, Italy
| | - Matteo Pirro
- Unit of Internal Medicine, Department of Medicine, University of Perugia, Perugia, Italy
| | - Arrigo F G Cicero
- Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy
| | - Amirhossein Sahebkar
- Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran; Neurogenic Inflammation Research Center, Mashhad University of Medical Sciences, Mashhad, Iran; School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
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Thilagar S, Santhanakrishnan M, Rao S. Expression of protease-activated receptors 1 and 2 in individuals with healthy gingiva and chronic periodontitis. J Indian Soc Periodontol 2018; 22:12-17. [PMID: 29568166 PMCID: PMC5855261 DOI: 10.4103/jisp.jisp_287_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Background Protease-activated receptors (PAR-1 and PAR-2) are found to be immensely exhibited in the periodontal tissues. These receptors are involved in the inflammatory and repair processes. Activation of PARs is mainly by the bacterial and endogenous enzymes. The aim of the study was to determine the role of PAR-1 and PAR-2 in initiating periodontal inflammation and to immunolocalize these receptors in the gingival tissues of healthy and chronic periodontitis individuals. Materials and Methods A total of 50 patients were selected for this study, of which 25 were healthy controls and 25 were chronic periodontitis patients. Gingival tissues were excised from the marginal gingiva and interdental papilla under local anesthesia (xylocaine with 2% adrenaline) during crown lengthening procedure or during periodontal therapy depending on the respective groups. Immunohistochemical analyses of PARs were done by staining the samples with hematoxylin and eosin and with primary and secondary antibody for PAR-1 and PAR-2. Results The Hematoxylin and Eosin staining showed more inflammatory changes in the periodontitis group compared to healthy gingiva. In chronic periodontitis, PAR-1-positive cells were seen in the basal layer with a weak expression and were showing negative expression in the superficial layer. In consideration of PAR-2, there was a very strong expression up to the superficial layer of the epithelium, compared to PAR-1. On comparing the intensity of staining in the connective tissue of chronic periodontitis sample, there was an increased expression of PAR-2 compared with PAR-1. A low positive expression of PAR-1 and PAR-2 was observed in the epithelium and connective tissue of the healthy tissues. Conclusion The results clearly demonstrated the role of PAR-1 and 2 in periodontal inflammation.
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Affiliation(s)
- Sivasankari Thilagar
- Department of Periodontics, Thai Moogambigai Dental College, Chennai, Tamil Nadu, India
| | | | - Suresh Rao
- Department of Periodontics, Sri Ramachandra Dental College, Chennai, Tamil Nadu, India
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Abstract
INTRODUCTION Tryptase is one of the main serine-proteinases located in the secretory granules of mast cells, and is released through degranulation, which is involved in the pathogenesis of allergic inflammatory disease, cardiovascular diseases, lung fibrosis and tumor. Therefore, inhibitors targeting tryptase may represent a new direction for the treatment of allergic inflammatory disease and other diseases. Areas covered: In this article, we discussed the history and development of tryptase inhibitors and described a variety of tryptase inhibitors via their structures and biological importance in clinical studies and drug development for tryptase-related diseases. Expert opinion: Initial tryptase inhibitors based on indole structure as the hydrophobic substituent on a benzylamine-piperidine template have low specificity and poor bioavailability. Therefore, designing new and specific inhibitors targeting tryptase should be involved in future clinical studies. Modifications toward indoles with varying N-substitution, introducing an amide bond, and growing the chain length contribute to an increase in the specific selectivity and potency of tryptase inhibitors. Tryptase has become the research hotspot to explore many related diseases. Therefore, there has been growing appreciation for the potential importance of the tryptase inhibitors as a target for treating these diseases.
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Affiliation(s)
- Wei-Wei Ni
- a Research Division of Clinical Pharmacology , the First Affiliated Hospital of Nanjing Medical University , Nanjing , Jiangsu , China
| | - Meng-Da Cao
- a Research Division of Clinical Pharmacology , the First Affiliated Hospital of Nanjing Medical University , Nanjing , Jiangsu , China
| | - Wen Huang
- a Research Division of Clinical Pharmacology , the First Affiliated Hospital of Nanjing Medical University , Nanjing , Jiangsu , China
| | - Ling Meng
- a Research Division of Clinical Pharmacology , the First Affiliated Hospital of Nanjing Medical University , Nanjing , Jiangsu , China
| | - Ji-Fu Wei
- a Research Division of Clinical Pharmacology , the First Affiliated Hospital of Nanjing Medical University , Nanjing , Jiangsu , China
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Rovai ES, Holzhausen M. The Role of Proteinase-Activated Receptors 1 and 2 in the Regulation of Periodontal Tissue Metabolism and Disease. J Immunol Res 2017; 2017:5193572. [PMID: 28503577 PMCID: PMC5414592 DOI: 10.1155/2017/5193572] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 01/13/2017] [Accepted: 03/05/2017] [Indexed: 01/13/2023] Open
Abstract
Proteinase-activated receptors 1 (PAR1) and 2 (PAR2) are the most highly expressed members of the PAR family in the periodontium. These receptors regulate periodontal inflammatory and repair processes through their activation by endogenous and bacterial enzymes. PAR1 is expressed by the periodontal cells such as human gingival fibroblasts, gingival epithelial cells, periodontal ligament cells, osteoblasts, and monocytic cells and can be activated by thrombin, matrix metalloproteinase 1 (MMP-1), MMP-13, fibrin, and gingipains from Porphyromonas gingivalis. PAR2 is expressed by neutrophils, osteoblasts, oral epithelial cells, and human gingival fibroblasts, and its possible activators in the periodontium are gingipains, neutrophil proteinase 3, and mast cell tryptase. The mechanisms through which PARs can respond to periodontal enzymes and result in appropriate immune responses have until recently been poorly understood. This review discusses recent findings that are beginning to identify a cardinal role for PAR1 and PAR2 on periodontal tissue metabolism.
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MESH Headings
- Adhesins, Bacterial/metabolism
- Animals
- Cells, Cultured
- Cysteine Endopeptidases/metabolism
- Epithelial Cells
- Fibroblasts
- Gene Expression Regulation
- Gingipain Cysteine Endopeptidases
- Gingiva/cytology
- Gingiva/metabolism
- Humans
- Matrix Metalloproteinase 1/genetics
- Matrix Metalloproteinase 1/metabolism
- Mice
- Periodontitis/genetics
- Periodontitis/metabolism
- Periodontitis/physiopathology
- Periodontium/metabolism
- Porphyromonas gingivalis
- Receptor, PAR-1/agonists
- Receptor, PAR-1/antagonists & inhibitors
- Receptor, PAR-1/genetics
- Receptor, PAR-1/metabolism
- Receptors, Proteinase-Activated/agonists
- Receptors, Proteinase-Activated/antagonists & inhibitors
- Receptors, Proteinase-Activated/genetics
- Receptors, Proteinase-Activated/metabolism
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Affiliation(s)
- E. S. Rovai
- Division of Periodontics, Department of Stomatology, School of Dentistry, University of São Paulo, São Paulo, SP, Brazil
| | - M. Holzhausen
- Division of Periodontics, Department of Stomatology, School of Dentistry, University of São Paulo, São Paulo, SP, Brazil
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Alfakry H, Malle E, Koyani CN, Pussinen PJ, Sorsa T. Neutrophil proteolytic activation cascades: a possible mechanistic link between chronic periodontitis and coronary heart disease. Innate Immun 2016; 22:85-99. [PMID: 26608308 DOI: 10.1177/1753425915617521] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 10/13/2015] [Indexed: 12/30/2022] Open
Abstract
Cardiovascular diseases are chronic inflammatory diseases that affect a large segment of society. Coronary heart disease (CHD), the most common cardiovascular disease, progresses over several years and affects millions of people worldwide. Chronic infections may contribute to the systemic inflammation and enhance the risk for CHD. Periodontitis is one of the most common chronic infections that affects up to 50% of the adult population. Under inflammatory conditions the activation of endogenous degradation pathways mediated by immune responses leads to the release of destructive cellular molecules from both resident and immigrant cells. Matrix metalloproteinases (MMPs) and their regulators can activate each other and play an important role in immune response via degrading extracellular matrix components and modulating cytokines and chemokines. The action of MMPs is required for immigrant cell recruitment at the site of inflammation. Stimulated neutrophils represent the major pathogen-fighting immune cells that upregulate expression of several proteinases and oxidative enzymes, which can degrade extracellular matrix components (e.g. MMP-8, MMP-9 and neutrophil elastase). The activity of MMPs is regulated by endogenous inhibitors and/or candidate MMPs (e.g. MMP-7). The balance between MMPs and their inhibitors is thought to mirror the proteolytic burden. Thus, neutrophil-derived biomarkers, including myeloperoxidase, may activate proteolytic destructive cascades that are involved in subsequent immune-pathological events associated with both periodontitis and CHD. Here, we review the existing studies on the contribution of MMPs and their regulators to the infection-related pathology. Also, we discuss the possible proteolytic involvement and role of neutrophil-derived enzymes as an etiological link between chronic periodontitis and CHD.
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Affiliation(s)
- Hatem Alfakry
- Department of Oral and Maxillofacial Diseases, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Ernst Malle
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Chintan N Koyani
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Pirkko J Pussinen
- Department of Oral and Maxillofacial Diseases, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Timo Sorsa
- Department of Oral and Maxillofacial Diseases, University of Helsinki and Helsinki University Hospital, Helsinki, Finland Division of Periodontology, Department of Dental Medicine, Karolinska Institutet, Huddinge, Sweden
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Franco FM, Jones DE, Harris PK, Han Z, Wildman SA, Jarvis CM, Janetka JW. Structure-based discovery of small molecule hepsin and HGFA protease inhibitors: Evaluation of potency and selectivity derived from distinct binding pockets. Bioorg Med Chem 2015; 23:2328-43. [DOI: 10.1016/j.bmc.2015.03.072] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2015] [Revised: 03/20/2015] [Accepted: 03/27/2015] [Indexed: 11/28/2022]
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de Araújo MF, Filho AFL, da Silva GP, de Melo MLR, Napimoga MH, Rodrigues DBR, Alves PM, de Lima Pereira SA. Evaluation of peri-implant mucosa: clinical, histopathological and immunological aspects. Arch Oral Biol 2014; 59:470-8. [PMID: 24631629 DOI: 10.1016/j.archoralbio.2014.01.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Revised: 12/13/2013] [Accepted: 01/28/2014] [Indexed: 12/31/2022]
Abstract
OBJECTIVE The aim was to compare the inflammatory response in peri-implant mucosa between patients with peri-implantitis (PP-group) and patients with healthy peri-implant tissues (HP-group). MATERIALS AND METHODS Two fragments of peri-implant mucosa of 18 patients were collected and serial sections were performed for histological and immunohistochemical analysis. RESULTS When compared with HP-group, PP-group showed higher immunostained cell density for TGF-β, IL-17 and CD31, beyond greater density of red cells, leukocytes, mast cells chymase (MCC) and mast cell tryptase (MCT). HP-group patients showed higher IL-13 expression and increased amount of collagen fibres when compared with PP-group. In PP-group there was significant positive correlation between MCT density and density of blood vessels immunostained, and between MCC density and density of blood vessels immunostained. There was significant negative correlation between the IL-17 density and collagen percentage. CONCLUSIONS This study demonstrated that in patients with peri-implantitis there was higher of TGF-β and IL-17, indicating that these cytokines are directly involved in the inflammatory process. Thus, understanding the influence of cytokines in the peri-implantitis installation, new therapies could be developed in order to inhibit the synthesis of IL-17 and induce synthesis of IL-13 in peri-implant tissue, contributing to increase the longevity of the implant.
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Affiliation(s)
| | | | | | | | - Marcelo Henrique Napimoga
- Laboratory of Immunology and Molecular Biology, São Leopoldo Mandic Institute and Research Center, Brazil
| | - Denise Bertulucci Rocha Rodrigues
- Laboratory of Biopathology and Molecular Biology, University of Uberaba (UNIUBE), Brazil; Cefores, Federal University of Triangulo Mineiro (UFTM), Brazil
| | | | - Sanivia Aparecida de Lima Pereira
- Laboratory of Biopathology and Molecular Biology, University of Uberaba (UNIUBE), Brazil; Cefores, Federal University of Triangulo Mineiro (UFTM), Brazil.
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Bao Y, Hou W, Hua B. Protease-activated receptor 2 signalling pathways: a role in pain processing. Expert Opin Ther Targets 2013; 18:15-27. [PMID: 24147628 DOI: 10.1517/14728222.2014.844792] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
INTRODUCTION Pain is a complex biological phenomenon that includes intricate neurophysiological, behavioural, psychosocial and affective components. Despite decades of pain research, many patients continue suffering from chronic pain that may be refractory to current medical regimens. Accumulating evidence has indicated an important role of protease-activated receptor 2 (PAR2) in the pathogenesis of pain, including inflammation, neuropathic and cancer pain. AREAS COVERED In this review, the role of the PAR2 signalling pathway in pain processes, basic mechanism of PAR2 activation and expression of PAR2 in the nervous system is covered. Furthermore, intracellular signalling pathways that are activated by PAR2 are also described. EXPERT OPINION The role of PAR2 in pain processing is becoming increasingly clear, and although causal implication remains to be established, PAR2 activation has been observed in several disease model systems. Since PAR2 is activated after nerve injury as well as by trypsin and related serine proteases, and PAR2 plays an important role in pain development and maintenance, exploring PAR2 and its corresponding signalling pathways will provide unfathomable knowledge in understanding the molecular basis of pain. This will also help to identify new targets for pharmacological intervention; however, in the context of potential PAR2-directed therapies, several aspects should be clarified.
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Affiliation(s)
- Yanju Bao
- Guang'anmen Hospital, China Academy of Chinese Medical Science, Department of Oncology , Beixiange 5, Xicheng District, Beijing 100053 , China +86 10 88001221 ; +86 10 88001430 ; ; ;
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