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Pagel CN, Kularathna PK, Sanaei R, Young ND, Hooper JD, Mackie EJ. Protease-activated receptor-2 dependent and independent responses of bone cells to prostate cancer cell secretory products. Prostate 2022; 82:723-739. [PMID: 35167724 DOI: 10.1002/pros.24316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 08/25/2021] [Accepted: 09/27/2021] [Indexed: 11/09/2022]
Abstract
BACKGROUND Metastatic prostate cancer lesions in the skeleton are frequently characterized by excessive formation of bone. Prostate cancer cells secrete factors, including serine proteases, that are capable of influencing the behavior of surrounding cells. Some of these proteases activate protease-activated receptor-2 (PAR2 ), which is expressed by osteoblasts (bone-forming cells) and precursors of osteoclasts (bone-resorbing cells). The aim of the current study was to investigate a possible role for PAR2 in regulating the behavior of bone cells exposed to metastatic prostate cancer cells. METHODS The effect of medium conditioned by the PC3, DU145, and MDA-PCa-2b prostate cancer cell lines was investigated in assays of bone cell function using cells isolated from wildtype and PAR2 -null mice. Osteoclast differentiation was assessed by counting tartrate-resistant acid phosphatase-positive multinucleate cells in bone marrow cultured in osteoclastogenic medium. Osteoblasts were isolated from calvariae of neonatal mice, and BrdU incorporation was used to assess their proliferation. Assays of alkaline phosphatase activity and quantitative PCR analysis of osteoblastic gene expression were used to assess osteoblast differentiation. Responses of osteoblasts to medium conditioned by MDA-PCa-2b cells were analyzed by RNAseq. RESULTS Conditioned medium (CM) from all three cell lines inhibited osteoclast differentiation independently of PAR2 . Media from PC3 and DU145 cells had no effect on assays of osteoblast function. Medium conditioned by MDA-PCa-2b cells stimulated BrdU incorporation in both wildtype and PAR2 -null osteoblasts but increased alkaline phosphatase activity and Runx2 and Col1a1 expression in wildtype but not PAR2 -null cells. Functional enrichment analysis of RNAseq data identified enrichment of multiple gene ontology terms associated with lysosomal function in both wildtype and PAR2 -null cells in response to MDA-PCa-2b-CM. Analysis of individual genes identified osteogenesis-associated genes that were either upregulated by MDA-PCa-2b-CM selectively in wildtype cells or downregulated selectively in PAR2 -null cells. CONCLUSIONS Factors secreted by prostate cancer cells influence bone cell behavior through both PAR2 -dependent and -independent mechanisms. Both PAR2 -independent suppression of osteoclast differentiation and PAR2 -dependent stimulation of osteogenesis are likely to determine the nature of prostate cancer metastases in bone.
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Affiliation(s)
- Charles N Pagel
- Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Pamu K Kularathna
- Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Reza Sanaei
- Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Neil D Young
- Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - John D Hooper
- Mater Research Institute, Translational Research Institute, University of Queensland, Woolloongabba, Queensland, Australia
| | - Eleanor J Mackie
- Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Victoria, Australia
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Sanaei R, Kularathna P, Taghavi N, Hooper J, Pagel C, Mackie E. Protease-activated receptor-2 promotes osteogenesis in skeletal mesenchymal stem cells at the expense of adipogenesis: Involvement of interleukin-6. Bone Rep 2021; 15:101113. [PMID: 34430676 PMCID: PMC8365448 DOI: 10.1016/j.bonr.2021.101113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 07/26/2021] [Accepted: 07/30/2021] [Indexed: 10/27/2022] Open
Abstract
Bone marrow mesenchymal stem cells (MSCs) give rise to osteoblasts and adipocytes, with an inverse relationship between the two. The MSCs from protease-activated receptor-2 knockout (PAR2 KO) mice have a reduced capacity to generate osteoblasts. Here we describe the observation that PAR2 KO osteoblastic cultures generate more adipocytes than wildtype (WT) cultures. Osteoblasts from PAR2 KO mice expressed lower levels of osteoblastic genes (Runx2, Col1a1 and Bglap), and higher levels of the adipocytic gene Pparg than WT osteoblasts. Bone marrow stromal cells from PAR2 KO mice generated fewer osteoblastic colonies (assessed by staining for alkaline phosphatase activity and mineral deposition) and more adipocytic (Oil Red-O positive) colonies than cultures from WT mice. Similarly, cultures of the bone marrow stromal cell line (Kusa 4b10) in which PAR2 was knocked down (F2rl1 KD), were less osteoblastic and more adipocytic than vector control cells. Putative regulators of PAR2-mediated osteogenesis and suppression of adipogenesis were identified in an RNA-sequencing (RNA-seq) investigation; these include C1qtnf3, Gpr35, Grem1, Snorc and Tcea3, which were more highly expressed, and Cnr1, Enpep, Hmgn5, Il6 and Ramp3 which were expressed at lower levels, in control than in F2rl1 KD cells. Interleukin-6 (IL-6) levels were higher in medium harvested from F2rl1 KD cells than from control cells, and a neutralising anti-IL-6 antibody reduced the number of adipocytes in F2rl1 KD cultures to that of control cultures. Thus, PAR2 appears to be a mediator of the reciprocal relationship between osteogenesis and adipogenesis, with IL-6 having a regulatory role in these PAR2-mediated effects.
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Affiliation(s)
- R. Sanaei
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - P.K. Kularathna
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - N. Taghavi
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - J.D. Hooper
- Mater Research Institute, The University of Queensland, Translational Research Institute, Woolloongabba, Queensland 4102, Australia
| | - C.N. Pagel
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - E.J. Mackie
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria 3010, Australia
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Lucena F, McDougall JJ. Protease Activated Receptors and Arthritis. Int J Mol Sci 2021; 22:9352. [PMID: 34502257 PMCID: PMC8430764 DOI: 10.3390/ijms22179352] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 08/23/2021] [Accepted: 08/26/2021] [Indexed: 12/14/2022] Open
Abstract
The catabolic and destructive activity of serine proteases in arthritic joints is well known; however, these enzymes can also signal pain and inflammation in joints. For example, thrombin, trypsin, tryptase, and neutrophil elastase cleave the extracellular N-terminus of a family of G protein-coupled receptors and the remaining tethered ligand sequence then binds to the same receptor to initiate a series of molecular signalling processes. These protease activated receptors (PARs) pervade multiple tissues and cells throughout joints where they have the potential to regulate joint homeostasis. Overall, joint PARs contribute to pain, inflammation, and structural integrity by altering vascular reactivity, nociceptor sensitivity, and tissue remodelling. This review highlights the therapeutic potential of targeting PARs to alleviate the pain and destructive nature of elevated proteases in various arthritic conditions.
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Affiliation(s)
| | - Jason J. McDougall
- Departments of Pharmacology and Anesthesia, Pain Management & Perioperative Medicine, Dalhousie University, 5850 College Street, Halifax, NS B3H 4R2, Canada;
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Lucena F, McDougall JJ. Pain responses to protease-activated receptor-2 stimulation in the spinal cord of naïve and arthritic rats. Neurosci Lett 2020; 739:135391. [PMID: 32949662 DOI: 10.1016/j.neulet.2020.135391] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 09/10/2020] [Accepted: 09/12/2020] [Indexed: 01/06/2023]
Abstract
There is strong evidence showing that the activation of peripheral proteinase-activated receptors type 2 (PAR-2) can initiate hyperalgesic and inflammatory responses in the joint. However, to date, there is no report of functional spinal PAR-2 receptors in arthritis models. The primary aim of this study was to evaluate the activity of PAR-2 receptors at the spinal cord by using a potent agonist (FLIGRL) in naïve animals, and an antagonist (GB83) in different models of joint pain. Saline or FLIGRL (10 nmol) were injected intrathecally in naïve animals and nociceptive behaviour was evaluated over a 24 h time period by von Frey hair algesiometry. Paw withdrawal threshold decreased from 3 to 24 h and this allodynic effect was blocked by GB83 (90 nmol; i.p.). Acute inflammatory joint pain was induced by injecting 0.5 % kaolin/carrageenan (50 μL each) into the right knee joint of male Wistar rats (24 h recovery). Chronic inflammatory joint pain was modelled by intraarticular injection of Freund's complete adjuvant (FCA; 50 μL; 7 days recovery) or chronic osteoarthritis pain by sodium monoiodoacetate (MIA; 3 mg; 14 days recovery). Animals were then treated with either intrathecal vehicle or 10 nmol of GB83 (10 μL); joint pain was evaluated throughout the subsequent 3 h period. The acute inflammatory pain induced by kaolin/carrageenan was not affected by treatment with GB83. Conversely, both chronic arthritis models demonstrated increased hind paw withdrawal threshold after spinal injection of the PAR-2 antagonist. Based on these results, spinal PAR-2 receptors are involved in joint nociceptive processing in chronic but not acute arthritic conditions.
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Affiliation(s)
- Flora Lucena
- Departments of Pharmacology and Anesthesia, Dalhousie University, 5850 College Street, Halifax, B3H 4R2, Canada.
| | - Jason J McDougall
- Departments of Pharmacology and Anesthesia, Dalhousie University, 5850 College Street, Halifax, B3H 4R2, Canada.
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Francis N, Ayodele BA, O'Brien-Simpson NM, Birchmeier W, Pike RN, Pagel CN, Mackie EJ. Keratinocyte-specific ablation of protease-activated receptor 2 prevents gingival inflammation and bone loss in a mouse model of periodontal disease. Cell Microbiol 2018; 20:e12891. [PMID: 30009515 DOI: 10.1111/cmi.12891] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 06/13/2018] [Accepted: 07/06/2018] [Indexed: 01/10/2023]
Abstract
Chronic periodontitis is characterised by gingival inflammation and alveolar bone loss. A major aetiological agent is Porphyromonas gingivalis, which secretes proteases that activate protease-activated receptor 2 (PAR2 ). PAR2 expressed on oral keratinocytes is activated by proteases released by P. gingivalis, inducing secretion of interleukin 6 (IL-6), and global knockout of PAR2 prevents bone loss and inflammation in a periodontal disease model in mice. To test the hypothesis that PAR2 expressed on gingival keratinocytes is required for periodontal disease pathology, keratinocyte-specific PAR2 -null mice were generated using K14-Cre targeted deletion of the PAR2 gene (F2rl1). These mice were subjected to a model of periodontitis involving placement of a ligature around a tooth, combined with P. gingivalis infection ("Lig + Inf"). The intervention caused a significant 44% decrease in alveolar bone volume (assessed by microcomputed tomography) in wildtype (K14-Cre:F2rl1wt/wt ), but not littermate keratinocyte-specific PAR2 -null (K14-Cre:F2rl1fl/fl ) mice. Keratinocyte-specific ablation of PAR2 prevented the significant Lig + Inf-induced increase (2.8-fold) in the number of osteoclasts in alveolar bone and the significant up-regulation (2.4-4-fold) of the inflammatory markers IL-6, IL-1β, interferon-γ, myeloperoxidase, and CD11b in gingival tissue. These data suggest that PAR2 expressed on oral epithelial cells is a critical regulator of periodontitis-induced bone loss and will help in designing novel therapies with which to treat the disease.
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Affiliation(s)
- Nidhish Francis
- Department of Veterinary Biosciences, Melbourne Veterinary School, University of Melbourne, Parkville, Victoria, Australia
| | - Babatunde A Ayodele
- Department of Veterinary Biosciences, Melbourne Veterinary School, University of Melbourne, Parkville, Victoria, Australia
| | - Neil M O'Brien-Simpson
- Melbourne Dental School, Bio21 Institute, University of Melbourne, Parkville, Victoria, Australia
| | | | - Robert N Pike
- La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Victoria, Australia
| | - Charles N Pagel
- Department of Veterinary Biosciences, Melbourne Veterinary School, University of Melbourne, Parkville, Victoria, Australia
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Oikonomopoulou K, Diamandis EP, Hollenberg MD, Chandran V. Proteinases and their receptors in inflammatory arthritis: an overview. Nat Rev Rheumatol 2018; 14:170-180. [PMID: 29416136 DOI: 10.1038/nrrheum.2018.17] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Proteinases are enzymes with established roles in physiological and pathological processes such as digestion and the homeostasis, destruction and repair of tissues. Over the past few years, the hormone-like properties of circulating proteinases have become increasingly appreciated. Some proteolytic enzymes trigger cell signalling via proteinase-activated receptors, a family of G protein-coupled receptors that have been implicated in inflammation and pain in inflammatory arthritis. Proteinases can also regulate ion flux owing to the cross-sensitization of transient receptor potential cation channel subfamily V members 1 and 4, which are associated with mechanosensing and pain. In this Review, the idea that proteinases have the potential to orchestrate inflammatory signals by interacting with receptors on cells within the synovial microenvironment of an inflamed joint is revisited in three arthritic diseases: osteoarthritis, spondyloarthritis and rheumatoid arthritis. Unanswered questions are highlighted and the therapeutic potential of modulating this proteinase-receptor axis for the management of disease in patients with these types of arthritis is also discussed.
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Affiliation(s)
- Katerina Oikonomopoulou
- Centre for Prognosis Studies in Rheumatic Diseases, Krembil Research Institute, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
| | - Eleftherios P Diamandis
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.,Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, Ontario, Canada.,Department of Clinical Biochemistry, University Health Network, Toronto, Ontario, Canada
| | - Morley D Hollenberg
- Department of Physiology & Pharmacology, University of Calgary Cumming School of Medicine, Calgary, Alberta, Canada.,Department of Medicine, University of Calgary Cumming School of Medicine, Calgary, Alberta, Canada
| | - Vinod Chandran
- Centre for Prognosis Studies in Rheumatic Diseases, Krembil Research Institute, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada.,Division of Rheumatology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada.,Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
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McCulloch K, McGrath S, Huesa C, Dunning L, Litherland G, Crilly A, Hultin L, Ferrell WR, Lockhart JC, Goodyear CS. Rheumatic Disease: Protease-Activated Receptor-2 in Synovial Joint Pathobiology. Front Endocrinol (Lausanne) 2018; 9:257. [PMID: 29875735 PMCID: PMC5974038 DOI: 10.3389/fendo.2018.00257] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 05/03/2018] [Indexed: 01/08/2023] Open
Abstract
Protease-activated receptor-2 (PAR2) is one member of a small family of transmembrane, G-protein-coupled receptors. These receptors are activated via cleavage of their N terminus by serine proteases (e.g., tryptase), unveiling an N terminus tethered ligand which binds to the second extracellular loop of the receptor. Increasing evidence has emerged identifying key pathophysiological roles for PAR2 in both rheumatoid arthritis (RA) and osteoarthritis (OA). Importantly, this includes both pro-inflammatory and destructive roles. For example, in murine models of RA, the associated synovitis, cartilage degradation, and subsequent bone erosion are all significantly reduced in the absence of PAR2. Similarly, in experimental models of OA, PAR2 disruption confers protection against cartilage degradation, subchondral bone osteosclerosis, and osteophyte formation. This review focuses on the role of PAR2 in rheumatic disease and its potential as an important therapeutic target for treating pain and joint degradation.
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Affiliation(s)
- Kendal McCulloch
- Institute of Biomedical & Environmental Health Research, University of the West of Scotland, Paisley, United Kingdom
| | - Sarah McGrath
- Institute of Immunity, Infection & Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Carmen Huesa
- Institute of Biomedical & Environmental Health Research, University of the West of Scotland, Paisley, United Kingdom
| | - Lynette Dunning
- Institute of Biomedical & Environmental Health Research, University of the West of Scotland, Paisley, United Kingdom
| | - Gary Litherland
- Institute of Biomedical & Environmental Health Research, University of the West of Scotland, Paisley, United Kingdom
| | - Anne Crilly
- Institute of Biomedical & Environmental Health Research, University of the West of Scotland, Paisley, United Kingdom
| | - Leif Hultin
- Respiratory, Inflammation and Autoimmunity, Innovative Medicines and Early Development, AstraZeneca, Mölndal, Sweden
| | - William R. Ferrell
- Institute of Immunity, Infection & Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - John C. Lockhart
- Institute of Biomedical & Environmental Health Research, University of the West of Scotland, Paisley, United Kingdom
- *Correspondence: John C. Lockhart, ; Carl S. Goodyear,
| | - Carl S. Goodyear
- Institute of Immunity, Infection & Inflammation, University of Glasgow, Glasgow, United Kingdom
- *Correspondence: John C. Lockhart, ; Carl S. Goodyear,
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8
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Lü Q, Gou Y, Tian F, Zhang L. [Research progress on protease-activated receptor 2 in pathogenesis of osteoarthritis]. ZHONGGUO XIU FU CHONG JIAN WAI KE ZA ZHI = ZHONGGUO XIUFU CHONGJIAN WAIKE ZAZHI = CHINESE JOURNAL OF REPARATIVE AND RECONSTRUCTIVE SURGERY 2017; 31:1517-1522. [PMID: 29806398 DOI: 10.7507/1002-1892.201705025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Objective To review the research progress on protease-activated receptor 2 (PAR-2) in the pathogenesis of osteoarthritis (OA). Methods The relevant literature about the mechanism of PAR-2 in the occurrence and development of OA in recent years was extensively reviewed and comprehensively analyzed. Results Abnormal activation of PAR-2 plays an important role in responses to occurrence and development of OA. Through regulating production and releasing of a variety of cytokines (such as inflammatory factors, metabolic factors, pain factors, etc.), the PAR-2 can involve in pathophysiological progression of OA articular cartilage, subchondral bone, and synovial membrane, as well as occurrence and transmission of pain. Conclusion PAR-2 participation in the development of OA has been confirmed. However, since PAR-2 is complicated and widespread, it is necessary to study the specific role of PAR-2 and the interaction between various signal pathways in the progression of OA, and to elucidate the potential pathophysiological mechanisms of PAR-2 participating in the process of OA, in the hope of exploring the new targets for the effective control of OA.
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Affiliation(s)
- Qinglie Lü
- Department of Orthopedics, Affiliated Hospital of North China University of Science and Technology, Tangshan Hebei, 063000, P.R.China
| | - Yu Gou
- Graduate School of Hebei Medical University, Shijiazhuang Hebei, 050017, P.R.China
| | - Faming Tian
- Medical Research Center, North China University of Science and Technology, Tangshan Hebei, 063000,
| | - Liu Zhang
- Department of Orthopedics, Affiliated Hospital of North China University of Science and Technology, Tangshan Hebei, 063000,
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Muley MM, Krustev E, Reid AR, McDougall JJ. Prophylactic inhibition of neutrophil elastase prevents the development of chronic neuropathic pain in osteoarthritic mice. J Neuroinflammation 2017; 14:168. [PMID: 28835277 PMCID: PMC5569523 DOI: 10.1186/s12974-017-0944-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 08/16/2017] [Indexed: 12/15/2022] Open
Abstract
Background A subset of osteoarthritis (OA) patients experience joint pain with neuropathic characteristics. Mediators such as neutrophil elastase, a serine proteinase, may be released during acute OA inflammatory flares. We have previously shown that local administration of neutrophil elastase causes joint inflammation and pain via activation of proteinase-activated receptor-2 (PAR2). The aim of this study was to examine the contribution of endogenous neutrophil elastase and PAR2 to the development of joint inflammation, pain, and neuropathy associated with monoiodoacetate (MIA)-induced experimental OA. Methods MIA (0.3 mg/10 μl) was injected into the right knee joint of male C57BL/6 mice (20–34 g). Joint inflammation (edema, leukocyte kinetics), neutrophil elastase proteolytic activity, tactile allodynia, and saphenous nerve demyelination were assessed over 14 days post-injection. The effects of inhibiting neutrophil elastase during the early inflammatory phase of MIA (days 0 to 3) were determined using sivelestat (50 mg/kg i.p.) and serpinA1 (10 μg i.p.). Involvement of PAR2 in the development of MIA-induced joint inflammation and pain was studied using the PAR2 antagonist GB83 (5 μg i.p. days 0 to 1) and PAR2 knockout animals. Results MIA caused an increase in neutrophil elastase proteolytic activity on day 1 (P < 0.0001), but not on day 14. MIA also generated a transient inflammatory response which peaked on day 1 (P < 0.01) then subsided over the 2-week time course. Joint pain appeared on day 1 and persisted to day 14 (P < 0.0001). By day 14, the saphenous nerve showed signs of demyelination. Early treatment with sivelestat and serpinA1 blocked the proteolytic activity of neutrophil elastase on day 1 (P < 0.001), and caused lasting improvements in joint inflammation, pain, and saphenous nerve damage (P < 0.05). MIA-induced synovitis was reversed by early treatment with GB83 and attenuated in PAR2 knockout mice (P < 0.05). PAR2 knockout mice also showed reduced MIA-induced joint pain (P < 0.0001) and less nerve demyelination (P = 0.81 compared to saline control). Conclusions Neutrophil elastase and PAR2 contribute significantly to the development of joint inflammation, pain, and peripheral neuropathy associated with experimental OA, suggesting their potential as therapeutic targets.
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Affiliation(s)
- Milind M Muley
- Departments of Pharmacology and Anaesthesia, Pain Management & Perioperative Medicine, Dalhousie University, 5850 College Street, PO Box 15000, Halifax, Nova Scotia, B3H 4R2, Canada
| | - Eugene Krustev
- Departments of Pharmacology and Anaesthesia, Pain Management & Perioperative Medicine, Dalhousie University, 5850 College Street, PO Box 15000, Halifax, Nova Scotia, B3H 4R2, Canada
| | - Allison R Reid
- Departments of Pharmacology and Anaesthesia, Pain Management & Perioperative Medicine, Dalhousie University, 5850 College Street, PO Box 15000, Halifax, Nova Scotia, B3H 4R2, Canada
| | - Jason J McDougall
- Departments of Pharmacology and Anaesthesia, Pain Management & Perioperative Medicine, Dalhousie University, 5850 College Street, PO Box 15000, Halifax, Nova Scotia, B3H 4R2, Canada.
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Alvarez M, Moura G, Machado M, Viana G, de Souza Costa C, Tjäderhane L, Nader H, Tersariol I, Nascimento F. PAR-1 and PAR-2 Expression Is Enhanced in Inflamed Odontoblast Cells. J Dent Res 2017; 96:1518-1525. [DOI: 10.1177/0022034517719415] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Affiliation(s)
- M.M.P. Alvarez
- Department of Biochemistry, Molecular Biology Division, Federal University of São Paulo (UNIFESP), São Paulo, Brazil
| | - G.E. Moura
- Department of Biochemistry, Molecular Biology Division, Federal University of São Paulo (UNIFESP), São Paulo, Brazil
| | - M.F.M. Machado
- Interdisciplinary Center of Biochemistry Investigation (CIIB), University of Mogi das Cruzes, Mogi das Cruzes, Brazil
| | - G.M. Viana
- Department of Biochemistry, Molecular Biology Division, Federal University of São Paulo (UNIFESP), São Paulo, Brazil
| | - C.A. de Souza Costa
- Department of Physiology and Pathology, Araraquara School of Dentistry, Univ Estadual Paulista–UNESP, São Paulo, Brazil
| | - L. Tjäderhane
- Department of Oral and Maxillofacial Diseases, University of Helsinki, and Helsinki University Hospital, Helsinki, Finland
- Research Unit of Oral Health Sciences and Medical Research Center Oulu (MRC Oulu), Oulu University Hospital and University of Oulu, Oulu, Finland
| | - H.B. Nader
- Department of Biochemistry, Molecular Biology Division, Federal University of São Paulo (UNIFESP), São Paulo, Brazil
| | - I.L.S. Tersariol
- Department of Biochemistry, Molecular Biology Division, Federal University of São Paulo (UNIFESP), São Paulo, Brazil
| | - F.D. Nascimento
- Interdisciplinary Center of Biochemistry Investigation (CIIB), University of Mogi das Cruzes, Mogi das Cruzes, Brazil
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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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Fukushima H, Alves VTE, Carvalho VFD, Ambrósio LMB, Eichler RADS, Carvalho MHCD, Saraiva L, Holzhausen M. PAR-2 expression in the gingival crevicular fluid reflects chronic periodontitis severity. Braz Oral Res 2017; 31:e16. [PMID: 28146220 DOI: 10.1590/1807-3107bor-2017.vol31.0016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 12/08/2016] [Indexed: 11/22/2022] Open
Abstract
Recent studies investigating protease-activated receptor type 2 (PAR-2) suggest an association between the receptor and periodontal inflammation. It is known that gingipain, a bacterial protease secreted by the important periodontopathogen Porphyromonas gingivalis can activate PAR-2. Previous studies by our group found that PAR-2 is overexpressed in the gingival crevicular fluid (GCF) of patients with moderate chronic periodontitis (MP). The present study aimed at evaluating whether PAR-2 expression is associated with chronic periodontitis severity. GCF samples and clinical parameters, including plaque and bleeding on probing indices, probing pocket depth and clinical attachment level, were collected from the control group (n = 19) at baseline, and from MP patients (n = 19) and severe chronic periodontitis (SP) (n = 19) patients before and 6 weeks after periodontal non-surgical treatment. PAR-2 and gingipain messenger RNA (mRNA) in the GCF of 4 periodontal sites per patient were evaluated by Reverse Transcription Polymerase Chain Reaction (RT-qPCR). PAR-2 and gingipain expressions were greater in periodontitis patients than in control group patients. In addition, the SP group presented increased PAR-2 and gingipain mRNA levels, compared with the MP group. Furthermore, periodontal treatment significantly reduced (p <0.05) PAR-2 expression in patients with periodontitis. In conclusion, PAR-2 is associated with chronic periodontitis severity and with gingipain levels in the periodontal pocket, thus suggesting that PAR-2 expression in the GCF reflects the severity of destruction during periodontal infection.
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Affiliation(s)
- Henrique Fukushima
- Universidade de São Paulo - USP, School of Dentistry, Department of Stomatology, São Paulo, SP, Brazil
| | | | | | | | | | | | - Luciana Saraiva
- Universidade de São Paulo - USP, School of Dentistry, Department of Stomatology, São Paulo, SP, Brazil
| | - Marinella Holzhausen
- Universidade de São Paulo - USP, School of Dentistry, Department of Stomatology, São Paulo, SP, Brazil
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13
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Rahman S, Pierce Campbell CM, Torres BN, O'Keefe MT, Ingles DJ, Villa LL, Carvalho da Silva RJ, Cintra RC, Lazcano-Ponce E, Salmeron J, Quiterio M, Giuliano AR. Distribution and factors associated with salivary secretory leukocyte protease inhibitor concentrations. Oral Dis 2016; 22:781-790. [PMID: 27470907 DOI: 10.1111/odi.12550] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 07/11/2016] [Accepted: 07/24/2016] [Indexed: 01/09/2023]
Abstract
OBJECTIVES This cross-sectional study examined the distribution and correlates of salivary secretory leukocyte protease inhibitor (SLPI) concentrations within a multinational cohort of men. METHODS Extracellular SLPI was measured in oral gargle cell supernatants of 378 men from three countries using an ELISA-based assay. Risk factor data were collected by a questionnaire. Factors associated with SLPI were assessed using linear and logistic regression for continuous and categorical SLPI, respectively. RESULTS Among men aged 18-73 years, the median SLPI concentration was 492.0 ng ml-1 (range: 2.3-1919.9). In multivariable modeling, men in Brazil and younger men (18-30 years) were more likely to have higher levels of SLPI [adjusted odds ratio (aOR) 3.84; 95% confidence interval (CI): 1.94-7.59, and aOR 3.84; 95% CI: 1.98-7.43, respectively]. Men with a self-reported sexually transmitted diseases diagnosis in the past 6 months were more likely to have higher SLPI levels (aOR 2.98; 95% CI: 1.1-7.83) and men reporting bleeding/swollen gums were less likely to have higher SLPI (aOR 0.34; 95% CI: 0.15-0.79). Similar results were observed for linear regression models. CONCLUSIONS Secretory leukocyte protease inhibitor concentrations varied significantly by country and decreased with increasing age. The interaction between SLPI, modifiable factors, and oral infections that influence cancer risk warrants further investigation.
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Affiliation(s)
- S Rahman
- Department of Epidemiology and Biostatistics, College of Public Health, University of South Florida, Tampa, FL, USA.,Department of Cancer Epidemiology, Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - C M Pierce Campbell
- Department of Cancer Epidemiology, Moffitt Cancer Center and Research Institute, Tampa, FL, USA.
| | - B N Torres
- Department of Biostatistics, Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - M T O'Keefe
- Department of Performance Improvement, Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - D J Ingles
- Vanderbilt Institute for Global Health, Nashville, TN, USA
| | - L L Villa
- Department of Radiology & Oncology, School of Medicine, University of São Paulo, São Paulo, Brazil
| | | | - R C Cintra
- Department of Biochemistry, Chemistry Institute, University of São Paulo, São Paulo, Brazil
| | | | - J Salmeron
- Instituto Nacional de Salúd Publica, Cuernavaca, Mexico.,Instituto Mexicano del Seguro Social, Cuernavaca, Mexico
| | - M Quiterio
- Instituto Nacional de Salúd Publica, Cuernavaca, Mexico
| | - A R Giuliano
- Department of Cancer Epidemiology, Moffitt Cancer Center and Research Institute, Tampa, FL, USA
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14
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Abreu IS, Euzebio Alves VT, Benedete APS, Bueno da Silva HA, França BN, Saraiva L, Lima LA, Carvalho MH, Holzhausen M. Gingival crevicular fluid levels of protease-activated receptors type 1 and type 2 in diabetic patients with periodontitis. J Periodontal Res 2015; 51:577-85. [PMID: 26564991 DOI: 10.1111/jre.12336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/25/2015] [Indexed: 11/28/2022]
Abstract
BACKGROUND AND OBJECTIVE Protease activated receptor type 1 (PAR1 ) seems to play a role in periodontal repair, while PAR2 is associated with periodontal inflammation. As diabetes is a known risk factor for periodontal disease, the aim of this study was to evaluate the influence of type 2 diabetes on PAR1 and PAR2 mRNA expression in the gingival crevicular fluid of patients with chronic periodontitis before and after non-surgical periodontal treatment. MATERIAL AND METHODS Gingival crevicular fluid samples and clinical parameters consisting of measuring probing depth, clinical attachment level, bleeding on probing and plaque index were collected from systemically healthy patients and patients with type 2 diabetes and chronic periodontitis, at baseline and after non-surgical periodontal therapy. PAR1 and PAR2 , as well as the presence of the proteases RgpB gingipain and neutrophil proteinase-3 were assessed by quantitative polymerase chain reaction in the gingival crevicular fluid. RESULTS The periodontal clinical parameters significantly improved after periodontal therapy (p < 0.01). Diabetes led to increased expression of PAR1 in gingival crevicular fluid, and in the presence of chronic periodontitis, it significantly decreased the expression of PAR1 and PAR2 (p < 0.05). Moreover, non-surgical periodontal treatment in diabetics resulted in increased expression of PAR1 and PAR2 (p < 0.05), and decreased expression of RgpB gingipain and proteinase-3 (p < 0.05). CONCLUSION The present data demonstrated that diabetes was associated with an altered expression of PAR1 and PAR2 in the gingival crevicular fluid cells of subjects with chronic periodontitis. Future studies are necessary to elucidate the effects of PAR1 upregulation in periodontally healthy sites and PAR2 downregulation in chronic periodontitis sites on the increased susceptibility and severity of periodontitis in diabetes.
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Affiliation(s)
- I S Abreu
- Division of Periodontics, Department of Stomatology, School of Dentistry, University of São Paulo, São Paulo, SP, Brazil
| | - V T Euzebio Alves
- Division of Periodontics, Department of Stomatology, School of Dentistry, University of São Paulo, São Paulo, SP, Brazil
| | - A P S Benedete
- Division of Periodontics, Department of Stomatology, School of Dentistry, University of São Paulo, São Paulo, SP, Brazil
| | - H A Bueno da Silva
- Division of Periodontics, Department of Stomatology, School of Dentistry, University of São Paulo, São Paulo, SP, Brazil
| | - B N França
- Division of Periodontics, Department of Stomatology, School of Dentistry, University of São Paulo, São Paulo, SP, Brazil
| | - L Saraiva
- Division of Periodontics, Department of Stomatology, School of Dentistry, University of São Paulo, São Paulo, SP, Brazil
| | - L A Lima
- Division of Periodontics, Department of Stomatology, School of Dentistry, University of São Paulo, São Paulo, SP, Brazil
| | - M H Carvalho
- Department of Pharmacology, Institute of Biomedical Sciences, 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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Jackson MT, Moradi B, Zaki S, Smith MM, McCracken S, Smith SM, Jackson CJ, Little CB. Depletion of protease-activated receptor 2 but not protease-activated receptor 1 may confer protection against osteoarthritis in mice through extracartilaginous mechanisms. Arthritis Rheumatol 2015; 66:3337-48. [PMID: 25200274 DOI: 10.1002/art.38876] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Accepted: 09/04/2014] [Indexed: 01/03/2023]
Abstract
OBJECTIVE To explore the involvement of protease-activated receptor 1 (PAR-1) and PAR-2 in the pathologic processes of osteoarthritis (OA) and to identify the cells/tissues primarily affected by ablation of PAR-1 or PAR-2 in mice. METHODS OA was induced in the joints of wild-type (WT), PAR-1(+/+) , PAR-1(-/-) , and PAR-2(-/-) mice by destabilization of the medial meniscus (DMM), and scores of histologic features (cartilage aggrecan loss and erosion, subchondral bone sclerosis, osteophytes, and synovitis) were compared at 1, 4, and 8 weeks post-DMM. The effects of PAR ablation on cartilage degradation and chondrocyte metalloproteinase expression/activity were studied in cultures of mouse femoral head tissue with or without interleukin-1α (IL-1α). At 1 week post-DMM, synovial expression of cytokines and metalloproteinase genes was measured by reverse transcription-polymerase chain reaction, and populations of inflammatory cells were quantified by flow cytometry. RESULTS Deletion of PAR-2, but not that of PAR-1, in mice significantly delayed the progression of cartilage damage and inhibited subchondral bone sclerosis following DMM. There was no inhibitory effect of PAR-1 or PAR-2 ablation on IL-1α-induced cartilage degradation or chondrocyte metalloproteinase expression/activation. A low but significant level of synovitis persisted in mice subjected to DMM compared to that in control mice subjected to sham surgery, but no differences between the genotypes were seen 4 or 8 weeks post-DMM. One week after DMM, increased synovial expression of proinflammatory cytokines and metalloproteinase genes, along with increased levels of CD4+ T cells, inflammatory monocytes, and activated macrophages, were seen in all genotypes. However, there was a significant reduction in the percentage of activated macrophages in PAR-2(-/-) mice compared to PAR-1(-/-) and WT mice. CONCLUSION Deletion of PAR-2, but not that of PAR-1, results in a significant decrease in DMM-induced cartilage damage. The chondroprotection in PAR-2(-/-) mice appears to occur indirectly through modulation of extracartilaginous events such as subchondral bone remodeling and synovial macrophage activation, rather than through alteration of chondrocyte catabolic responses.
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Affiliation(s)
- Miriam T Jackson
- Kolling Institute of Medical Research and the University of Sydney at Royal North Shore Hospital, St. Leonards, New South Wales, Australia
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16
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Kularathna PK, Pagel CN, Mackie EJ. Tumour progression and cancer-induced pain: a role for protease-activated receptor-2? Int J Biochem Cell Biol 2014; 57:149-56. [PMID: 25448411 DOI: 10.1016/j.biocel.2014.10.026] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Accepted: 10/23/2014] [Indexed: 02/08/2023]
Abstract
The role of proteases in modifying the microenvironment of tumour cells has long been recognised. With the discovery of the protease-activated receptor family of G protein-coupled receptors a mechanism for cells to sense and respond directly to proteases in their microenvironment was revealed. Many early studies described the roles of protease-activated receptors in the cellular events that occur during blood coagulation and inflammation. More recently, studies have begun to focus on the roles of protease-activated receptors in the establishment, progression and metastasis of a variety of tumours. This review will focus on the expression of protease-activated receptor-2 and its activators by normal and neoplastic tissues, and describe current evidence that activation of protease-activated receptor-2 is an important event at multiple stages of tumour progression and in pain associated with cancer.
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Affiliation(s)
- Pamuditha K Kularathna
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Charles N Pagel
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Eleanor J Mackie
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Victoria 3010, Australia.
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17
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Periodontal treatment downregulates protease-activated receptor 2 in human gingival crevicular fluid cells. Infect Immun 2013; 81:4399-407. [PMID: 24042113 DOI: 10.1128/iai.01107-13] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Protease-activated receptor 2 (PAR2) is implicated in the pathogenesis of chronic inflammatory diseases, including periodontitis; it can be activated by gingipain and produced by Porphyromonas gingivalis and by neutrophil protease 3 (P3). PAR2 activation plays a relevant role in inflammatory processes by inducing the release of important inflammatory mediators associated with periodontal breakdown. The effects of periodontal treatment on PAR2 expression and its association with levels of proinflammatory mediators and activating proteases were investigated in chronic periodontitis patients. Positive staining for PAR2 was observed in gingival crevicular fluid cells and was reflective of tissue destruction. Overexpression of PAR2 was positively associated with inflammatory clinical parameters and with the levels of interleukin-6 (IL-6), IL-8, tumor necrosis factor alpha, matrix metalloprotease 2 (MMP-2), MMP-8, hepatocyte growth factor, and vascular endothelial growth factor. Elevated levels of gingipain and P3 and decreased levels of dentilisin and the protease inhibitors secretory leukocyte protease inhibitor and elafin were also associated with PAR2 overexpression. Healthy periodontal sites from individuals with chronic periodontitis showed diminished expression of PAR2 mRNA and the PAR2 protein (P < 0.05). Furthermore, periodontal treatment resulted in decreased PAR2 expression and correlated with decreased expression of inflammatory mediators and activating proteases. We concluded that periodontal treatment resulted in decreased levels of proteases and that proinflammatory mediators are associated with decreased PAR2 expression, suggesting that PAR2 expression is influenced by the presence of periodontal infection and is not a constitutive characteristic favoring periodontal inflammation.
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18
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O'Neill KR, Stutz CM, Mignemi NA, Cole H, Murry MR, Nyman JS, Hamm H, Schoenecker JG. Fracture healing in protease-activated receptor-2 deficient mice. J Orthop Res 2012; 30:1271-6. [PMID: 22247070 DOI: 10.1002/jor.22071] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Accepted: 12/20/2011] [Indexed: 02/04/2023]
Abstract
Protease-activated receptor-2 (PAR-2) provides an important link between extracellular proteases and the cellular initiation of inflammatory responses. The effect of PAR-2 on fracture healing is unknown. This study investigates the in vivo effect of PAR-2 deletion on fracture healing by assessing differences between wild-type (PAR-2(+/+)) and knock-out (PAR-2(-/-)) mice. Unilateral mid-shaft femur fractures were created in 34 PAR-2(+/+) and 28 PAR-2(-/-) mice after intramedullary fixation. Histologic assessments were made at 1, 2, and 4 weeks post-fracture (wpf), and radiographic (plain radiographs, micro-computed tomography (µCT)) and biomechanical (torsion testing) assessments were made at 7 and 10 wpf. Both the fractured and un-fractured contralateral femur specimens were evaluated. Polar moment of inertia (pMOI), tissue mineral density (TMD), bone volume fraction (BV/TV) were determined from µCT images, and callus diameter was determined from plain radiographs. Statistically significant differences in callus morphology as assessed by µCT were found between PAR-2(-/-) and PAR-2(+/+) mice at both 7 and 10 wpf. However, no significant histologic, plain radiographic, or biomechanical differences were found between the genotypes. The loss of PAR-2 was found to alter callus morphology as assessed by µCT but was not found to otherwise effect fracture healing in young mice.
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Affiliation(s)
- Kevin R O'Neill
- Department of Orthopaedics, Vanderbilt University Medical Center, Nashville, Tennessee 37232-9565, USA
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19
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Host-bacteria crosstalk at the dentogingival junction. Int J Dent 2012; 2012:821383. [PMID: 22899931 PMCID: PMC3412119 DOI: 10.1155/2012/821383] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Revised: 05/22/2012] [Accepted: 05/22/2012] [Indexed: 12/21/2022] Open
Abstract
The dentogingival junction is of crucial importance in periodontal host defense both structurally and functionally. Oral bacteria exert a constant challenge to the host cells and tissues at the dentogingival junction. The host response is set up to eliminate the pathogens by the innate and adaptive defense mechanisms. In health, the commensal bacteria and the host defense mechanisms are in a dynamic steady state. During periodontal disease progression, the dental bacterial plaque, junctional epithelium (JE), inflammatory cells, connective tissue, and bone all go through a series of changes. The tissue homeostasis is turned into tissue destruction and progression of periodontitis. The classical study of Slots showed that in the bacterial plaque, the most remarkable change is the shift from gram-positive aerobic and facultatively anaerobic flora to a predominantly gram-negative and anaerobic flora. This has been later confirmed by several other studies. Furthermore, not only the shift of the bacterial flora to a more pathogenic one, but also bacterial growth as a biofilm on the tooth surface, allows the bacteria to communicate with each other and exert their virulence aimed at favoring their growth. This paper focuses on host-bacteria crosstalk at the dentogingival junction and the models studying it in vitro.
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20
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Georgy SR, Pagel CN, Ghasem-Zadeh A, Zebaze RMD, Pike RN, Sims NA, Mackie EJ. Proteinase-activated receptor-2 is required for normal osteoblast and osteoclast differentiation during skeletal growth and repair. Bone 2012; 50:704-12. [PMID: 22173052 DOI: 10.1016/j.bone.2011.11.023] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2011] [Revised: 11/23/2011] [Accepted: 11/24/2011] [Indexed: 10/14/2022]
Abstract
Proteinase-activated receptor-2 (PAR(2)) is a G-protein coupled receptor expressed by osteoblasts and monocytes. PAR(2) is activated by a number of proteinases including coagulation factors and proteinases released by inflammatory cells. The aim of the current study was to investigate the role of PAR(2) in skeletal growth and repair using wild type (WT) and PAR(2) knockout (KO) mice. Micro computed tomography and histomorphometry were used to examine the structure of tibias isolated from uninjured mice at 50 and 90 days of age, and from 98-day-old mice in a bone repair model in which a hole had been drilled through the tibias. Bone marrow was cultured and investigated for the presence of osteoblast precursors (alkaline phosphatase-positive fibroblastic colonies), and osteoclasts were counted in cultures treated with M-CSF and RANKL. Polymerase chain reaction (PCR) was used to determine which proteinases that activate PAR(2) are expressed in bone marrow. Regulation of PAR(2) expression in primary calvarial osteoblasts from WT mice was investigated by quantitative PCR. Cortical and trabecular bone volumes were significantly greater in the tibias of PAR(2) KO mice than in those of WT mice at 50 days of age. In trabecular bone, osteoclast surface, osteoblast surface and osteoid volume were significantly lower in KO than in WT mice. Bone marrow cultures from KO mice showed significantly fewer alkaline phosphatase-positive colony-forming units and osteoclasts compared to cultures from WT mice. Significantly less new bone and significantly fewer osteoclasts were observed in the drill sites of PAR(2) KO mice compared to WT mice 7 days post-surgery. A number of activators of PAR(2), including matriptase and kallikrein 4, were found to be expressed by normal bone marrow. Parathyroid hormone, 1,25 dihydroxyvitamin D(3), or interleukin-6 in combination with its soluble receptor down-regulated PAR(2) mRNA expression, and fibroblast growth factor-2 or thrombin stimulated PAR(2) expression. These results suggest that PAR(2) activation contributes to determination of cells of both osteoblast and osteoclast lineages within bone marrow, and thereby participates in the regulation of skeletal growth and bone repair.
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Affiliation(s)
- S R Georgy
- School of Veterinary Science, University of Melbourne, Parkville, Victoria 3010, Australia
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21
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Guo Y, Nguyen KA, Potempa J. Dichotomy of gingipains action as virulence factors: from cleaving substrates with the precision of a surgeon's knife to a meat chopper-like brutal degradation of proteins. Periodontol 2000 2010; 54:15-44. [PMID: 20712631 DOI: 10.1111/j.1600-0757.2010.00377.x] [Citation(s) in RCA: 248] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Holzhausen M, Balejo RDP, Lara GM, Cortelli SC, Saad WA, Cortelli JR. Nafamostat mesilate, a potent tryptase inhibitor, modulates periodontitis in rats. Clin Oral Investig 2010; 15:967-73. [PMID: 20820824 DOI: 10.1007/s00784-010-0463-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Accepted: 08/25/2010] [Indexed: 01/04/2023]
Abstract
Previous reports have demonstrated increased tryptase-like proteolytic activity in the crevicular fluid of patients with periodontal disease. In the present study, we have investigated the effect of tryptase inhibition with nafamostat mesilate (NM, 6-amino-2-naphtlyl p-guanidinobenzoate dimethansulfonate) on the development of experimental periodontitis in rats. Eighty (80) male Wistar rats were randomly separated into four groups: Control group, NM group (daily 0.1 mg/kg body weight of NM, i.p.), Ligature group (ligature placed at lower right first molars), and NM+Ligature group. The amount of alveolar bone loss (ABL) around the mesial root surface of the first mandibulary molar, as well as the myeloperoxidase (MPO) activity, and total proteolytic activity [N-benzoyl-L: -arginine-p-nitroanilide (BApNA) substrate] were determined at 7 and 14 days. NM led to significantly (p < 0.05) decreased ABL in animals subjected to ligature-induced periodontitis. Tryptase inhibition prevented the onset of significant ABL at 7 days of experiment (0.44 ± 0.16 and 0.60 ± 0.22, p > 0.05, NM+Ligature and Control, respectively) and significantly decreased the ABL at 14 days (0.97 ± 0.17 versus 1.82 ± 0.26, p < 0.001, NM+Ligature versus Ligature, respectively). In addition, NM significantly decreased MPO and total proteolytic activity at 14 days (p < 0.05). These data provided evidence that tryptase inhibition with NM attenuates gingival granulocyte infiltration and ABL in an experimental model of periodontitis in rats.
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Affiliation(s)
- Marinella Holzhausen
- Division of Periodontics, Department of Stomatology, School of Dentistry, University of São Paulo, São Paulo, SP, Brazil.
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23
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Holzhausen M, Cortelli J, da Silva VA, Franco GN, Cortelli SC, Vergnolle N. Protease-activated Receptor-2 (par2) in Human Periodontitis. J Dent Res 2010; 89:948-53. [DOI: 10.1177/0022034510373765] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
No evidence for the role of protease-activated receptor-2 (PAR2) in human periodontal disease has been demonstrated so far. Thus, we sought to investigate the expression of PAR2 mRNA in chronic periodontitis, and to examine whether its expression is related to the presence of PAR2 potential activators. Microbiological and gingival crevicular fluid samples were collected from individuals with chronic periodontitis and control individuals, and the presence of neutrophil serine proteinase 3 (P3) and Porphyromonas gingivalis was evaluated. PAR2 mRNA expression was higher (p < 0.001) in those with chronic periodontitis compared with control individuals, and it was statistically decreased (p = 0.0006) after periodontal treatment. Furthermore, those with chronic periodontitis presented higher (p < 0.05) levels of IL-1α, IL-6, IL-8, and TNF-α, total proteolytic activity, P. gingivalis prevalence, and P3mRNA expression compared with control individuals. We conclude that PAR2 mRNA expression and its potential activators are elevated in human chronic periodontitis, therefore suggesting that PAR2 may play a role in periodontal inflammation.
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Affiliation(s)
- M. Holzhausen
- Division of Periodontics, Department of Stomatology, School of Dentistry, University of São Paulo, São Paulo, SP, Avenida Prof. Lineu Prestes, 2227, Cidade Universitária, São Paulo-SP, CEP: 05508-000, Brazil
| | - J.R. Cortelli
- Division of Periodontics, Department of Stomatology, School of Dentistry, University of São Paulo, São Paulo, SP, Avenida Prof. Lineu Prestes, 2227, Cidade Universitária, São Paulo-SP, CEP: 05508-000, Brazil
| | - V. Araújo da Silva
- Division of Periodontics, Department of Stomatology, School of Dentistry, University of São Paulo, São Paulo, SP, Avenida Prof. Lineu Prestes, 2227, Cidade Universitária, São Paulo-SP, CEP: 05508-000, Brazil
| | - G.C. Nobre Franco
- Division of Periodontics, Department of Stomatology, School of Dentistry, University of São Paulo, São Paulo, SP, Avenida Prof. Lineu Prestes, 2227, Cidade Universitária, São Paulo-SP, CEP: 05508-000, Brazil
| | - S. Cavalca Cortelli
- Division of Periodontics, Department of Stomatology, School of Dentistry, University of São Paulo, São Paulo, SP, Avenida Prof. Lineu Prestes, 2227, Cidade Universitária, São Paulo-SP, CEP: 05508-000, Brazil
| | - N. Vergnolle
- INSERM U563, Centre de Physiopathologie de Toulouse Purpan, Toulouse, F-31300, France
- Université de Toulouse III Paul Sabatier, Toulouse, F-31000, France
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Bartold PM, Cantley MD, Haynes DR. Mechanisms and control of pathologic bone loss in periodontitis. Periodontol 2000 2010; 53:55-69. [DOI: 10.1111/j.1600-0757.2010.00347.x] [Citation(s) in RCA: 150] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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25
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Georgy SR, Pagel CN, Wong DM, Sivagurunathan S, Loh LH, Myers DE, Hollenberg MD, Pike RN, Mackie EJ. Proteinase-activated receptor-2 (PAR2) and mouse osteoblasts: Regulation of cell function and lack of specificity of PAR2-activating peptides. Clin Exp Pharmacol Physiol 2010; 37:328-36. [DOI: 10.1111/j.1440-1681.2009.05294.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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26
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Regulation of protease-activated receptor-2 expression in gingival fibroblasts and Jurkat T cells byPorphyromonas gingivalis. Cell Biol Int 2010; 34:287-92. [DOI: 10.1042/cbi20090290] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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27
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Protease-activated receptor 2 has pivotal roles in cellular mechanisms involved in experimental periodontitis. Infect Immun 2009; 78:629-38. [PMID: 19933835 DOI: 10.1128/iai.01019-09] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The tissue destruction seen in chronic periodontitis is commonly accepted to involve extensive upregulation of the host inflammatory response. Protease-activated receptor 2 (PAR-2)-null mice infected with Porphyromonas gingivalis did not display periodontal bone resorption in contrast to wild-type-infected and PAR-1-null-infected mice. Histological examination of tissues confirmed the lowered bone resorption in PAR-2-null mice and identified a substantial decrease in mast cells infiltrating the periodontal tissues of these mice. T cells from P. gingivalis-infected or immunized PAR-2-null mice proliferated less in response to antigen than those from wild-type animals. CD90 (Thy1.2) expression on CD4(+) and CD8(+) T-cell-receptor beta (TCRbeta) T cells was significantly (P < 0.001) decreased in antigen-immunized PAR-2-null mice compared to sham-immunized PAR-2-null mice; this was not observed in wild-type controls. T cells from infected or antigen-immunized PAR-2-null mice had a significantly different Th1/inflammatory cytokine profile from wild-type cells: in particular, gamma interferon, interleukins (interleukin-2, -3, and -17), granulocyte-macrophage colony-stimulating factor, and tumor necrosis factor alpha demonstrated lower expression than wild-type controls. The absence of PAR-2 therefore appears to substantially decrease T-cell activation and the Th1/inflammatory response. Regulation of such proinflammatory mechanisms in T cells and mast cells by PAR-2 suggests a pivotal role in the pathogenesis of the disease.
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Shimada T, Sugano N, Ikeda K, Shimada K, Iizuka T, Ito K. Protease-activated receptor 2 mediates interleukin-8 and intercellular adhesion molecule-1 expression in response to Aggregatibacter actinomycetemcomitans. ACTA ACUST UNITED AC 2009; 24:285-91. [PMID: 19572889 DOI: 10.1111/j.1399-302x.2009.00507.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
INTRODUCTION We investigated the mechanisms by which extracts of Aggregatibacter actinomycetemcomitans affect the inflammatory response in gingival epithelial cells. METHODS Human gingival cells (Ca9-22) were cultured in bacterial extracts prepared from A. actinomycetemcomitans ATCC 29522. The cells were pretreated with protease inhibitors or transfected with small interfering RNA (siRNA) specific for protease-activated receptor 2 (PAR-2). RESULTS The pretreatment of cells with serine protease inhibitors significantly inhibited A. actinomycetemcomitans extract-induced expression of interleukin-8 (IL-8) and intercellular adhesion molecule-1 (ICAM-1) at both the messenger RNA and protein levels. In addition, A. actinomycetemcomitans extract-induced IL-8 and ICAM-1 expression was significantly decreased in PAR-2/siRNA-transfected cells. CONCLUSIONS A. actinomycetemcomitans extract-induced IL-8 and ICAM-1 expression in gingival epithelial cells is mediated by PAR-2.
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Affiliation(s)
- T Shimada
- Nihon University Graduate School of Dentistry, Tokyo 101-8310, Japan
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Amiable N, Tat SK, Lajeunesse D, Duval N, Pelletier JP, Martel-Pelletier J, Boileau C. Proteinase-activated receptor (PAR)-2 activation impacts bone resorptive properties of human osteoarthritic subchondral bone osteoblasts. Bone 2009; 44:1143-50. [PMID: 19264156 PMCID: PMC5250314 DOI: 10.1016/j.bone.2009.02.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2008] [Revised: 02/12/2009] [Accepted: 02/17/2009] [Indexed: 10/21/2022]
Abstract
INTRODUCTION In osteoarthritis (OA), the subchondral bone undergoes a remodelling process involving several factors synthesized by osteoblasts. In this study, we investigated the expression, production, modulation, and role of PAR-2 in human OA subchondral bone osteoblasts. MATERIALS AND METHODS PAR-2 expression and production were determined by real-time PCR and flow cytometry, respectively. PAR-2 modulation was investigated in OA subchondral bone osteoblasts treated with IL-1 beta (100 pg/ml), TNF-alpha (5 ng/ml), TGF-beta1 (10 ng/ml), PGE(2) (500 nM), IL-6 (10 ng/ml) and IL-17 (10 ng/ml). Membranous RANKL protein was assessed by flow cytometry, and OPG, MMP-1, MMP-9, MMP-13, IL-6 and intracellular signalling pathways by specific ELISAs. Bone resorptive activity was measured by using a co-culture model of human PBMC and OA subchondral bone osteoblasts. RESULTS PAR-2 expression and production (p<0.05) were markedly increased when human OA subchondral bone osteoblasts were compared to normal. On OA osteoblasts, PAR-2 production was significantly increased by IL-1 beta, TNF-alpha and PGE(2). Activation of PAR-2 with a specific agonist, SLIGKV-NH(2), induced a significant up-regulation of MMP-1, MMP-9, IL-6, and membranous RANKL, but had no effect on MMP-13 or OPG production. Interestingly, bone resorptive activity was also significantly enhanced following PAR-2 activation. The PAR-2 effect was mediated by activation of the MAP kinases Erk1/2 and JNK. CONCLUSION This study is the first to demonstrate that PAR-2 activation plays a role in OA subchondral bone resorption via an up-regulation of major bone remodelling factors. These results shed new light on the potential of PAR-2 as a therapeutic target in OA.
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Affiliation(s)
- Nathalie Amiable
- Osteoarthritis Research Unit, University of Montreal Hospital Centre (CRCHUM), Notre-Dame Hospital, 1560 Sherbrooke Street East, Montreal, Quebec, Canada.
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Hsieh HL, Sun CC, Wang TS, Yang CM. PKC-δ/c-Src-mediated EGF receptor transactivation regulates thrombin-induced COX-2 expression and PGE2 production in rat vascular smooth muscle cells. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2008; 1783:1563-75. [DOI: 10.1016/j.bbamcr.2008.03.016] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2007] [Revised: 03/12/2008] [Accepted: 03/27/2008] [Indexed: 01/25/2023]
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Kida Y, Higashimoto Y, Inoue H, Shimizu T, Kuwano K. A novel secreted protease from Pseudomonas aeruginosa activates NF-κB through protease-activated receptors. Cell Microbiol 2008; 10:1491-504. [DOI: 10.1111/j.1462-5822.2008.01142.x] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Ohno T, Okahashi N, Morisaki I, Amano A. Signaling pathways in osteoblast proinflammatory responses to infection by Porphyromonas gingivalis. ACTA ACUST UNITED AC 2008; 23:96-104. [DOI: 10.1111/j.1399-302x.2007.00393.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Ramsay AJ, Dong Y, Hunt ML, Linn M, Samaratunga H, Clements JA, Hooper JD. Kallikrein-related peptidase 4 (KLK4) initiates intracellular signaling via protease-activated receptors (PARs). KLK4 and PAR-2 are co-expressed during prostate cancer progression. J Biol Chem 2008; 283:12293-304. [PMID: 18308730 DOI: 10.1074/jbc.m709493200] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Kallikrein-related peptidase 4 (KLK4) is one of the 15 members of the human KLK family and a trypsin-like, prostate cancer-associated serine protease. Signaling initiated by trypsin-like serine proteases are transduced across the plasma membrane primarily by members of the protease-activated receptor (PAR) family of G protein-coupled receptors. Here we show, using Ca(2+) flux assays, that KLK4 signals via both PAR-1 and PAR-2 but not via PAR-4. Dose-response analysis over the enzyme concentration range 0.1-1000 nM indicated that KLK4-induced Ca(2+) mobilization via PAR-1 is more potent than via PAR-2, whereas KLK4 displayed greater efficacy via the latter PAR. We confirmed the specificity of KLK4 signaling via PAR-2 using in vitro protease cleavage assays and anti-phospho-ERK1/2/total ERK1/2 Western blot analysis of PAR-2-overexpressing and small interfering RNA-mediated receptor knockdown cell lines. Consistently, confocal microscopy analyses indicated that KLK4 initiates loss of PAR-2 from the cell surface and receptor internalization. Immunohistochemical analysis indicated the co-expression of agonist and PAR-2 in primary prostate cancer and bone metastases, suggesting that KLK4 signaling via this receptor will have pathological relevance. These data provide insight into KLK4-mediated cell signaling and suggest that signals induced by this enzyme via PARs may be important in prostate cancer.
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Affiliation(s)
- Andrew J Ramsay
- Institute of Health and Biomedical Innovation and School of Life Sciences, Queensland University of Technology, Corner Musk Ave. and Blamey St., Kelvin Grove, Queensland 4059, Australia
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Hu Y, Ek-Rylander B, Karlström E, Wendel M, Andersson G. Osteoclast size heterogeneity in rat long bones is associated with differences in adhesive ligand specificity. Exp Cell Res 2007; 314:638-50. [PMID: 18086469 DOI: 10.1016/j.yexcr.2007.11.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2007] [Revised: 11/09/2007] [Accepted: 11/12/2007] [Indexed: 01/15/2023]
Abstract
Prothrombin (PT) is an RGD-containing bone-residing precursor to the serine protease thrombin (TH), which acts as an agonist for a variety of cellular responses in osteoblasts and osteoclasts. We show here that PT, TH, osteopontin (OPN) and fibronectin (FN) promoted adhesion of isolated neonatal rat long bone osteoclasts. However, the cells that adhered to PT and TH were smaller in size, rounded and contained 3-4 nuclei, in comparison to the cells adhering to OPN and FN, which were larger with extended cytoplasmic processes and 6-7 nuclei. Attachment of the larger osteoclasts to OPN and FN was inhibited by antibodies towards beta 3 and beta 1 integrin subunits, respectively. Whereas an RGD-containing peptide inhibited adhesion of the smaller osteoclasts to PT and TH, this was not seen with the beta 3 or beta 1 antibodies. In contrast, the beta 1 antibody augmented osteoclast adhesion to PT and TH in an RGD-dependent manner. Small osteoclasts were less efficient in resorbing mineralized bovine bone slices, as well as expressed lower mRNA levels of MMP-9 and the cathepsins K and L compared to large osteoclasts. The small osteoclast adhering to PT and TH may represent either an immature, less functional precursor to the large osteoclast or alternatively constitute a distinct osteoclast population with a specific role in bone.
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Affiliation(s)
- Yingwei Hu
- Center for Oral Biology, Department of Odontology, Karolinska Institutet, SE-141 04 Huddinge, Sweden
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Daubie V, De Decker R, Nicaise C, Pochet R. Osteosarcoma cell-calcium signaling through tissue factor-factor VIIa complex and factor Xa. FEBS Lett 2007; 581:2611-5. [PMID: 17509570 DOI: 10.1016/j.febslet.2007.04.078] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2007] [Revised: 03/28/2007] [Accepted: 04/18/2007] [Indexed: 11/15/2022]
Abstract
The cells responsible for bone formation express protease-activated receptors. Although serine protease thrombin has been shown to elicit functional responses in bone cells that impact on cell survival and alkaline phosphatase activity, nothing is known about tissue factor, factor VIIa, and factor Xa, the serine proteases that act upstream of thrombin in the coagulation cascade. This paper demonstrates that tissue factor is expressed in the osteoblast-like cell line SaOS-2 and, that tissue factor in a factor VIIa-bound complex induces a transient intracellular Ca(2+) increase through protease-activated receptor-2. In SaOS-2 cells, factor Xa induced a sustained intracellular Ca(2+) response, as does SLIGRL, a PAR2-activating peptide, and PAR-1-dependent cell viability.
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Affiliation(s)
- Valéry Daubie
- Laboratory of Histology, Neuroanatomy and Neuropathology, CP620, Université Libre de Bruxelles Route de Lennik 808, Bruxelles, Belgium.
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Holzhausen M, Spolidorio LC, Ellen RP, Jobin MC, Steinhoff M, Andrade-Gordon P, Vergnolle N. Protease-activated receptor-2 activation: a major role in the pathogenesis of Porphyromonas gingivalis infection. THE AMERICAN JOURNAL OF PATHOLOGY 2006; 168:1189-99. [PMID: 16565494 PMCID: PMC1606564 DOI: 10.2353/ajpath.2006.050658] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
We have investigated the specific contribution of protease-activated receptor-2 (PAR(2)) to host defense during Porphyromonas gingivalis infection. Culture supernatants from P. gingivalis strains 33277 and W50 provoked Ca(2+) mobilization in cells transfected with PAR(2) (PAR(2)-KNRK) and desensitized the subsequent responses to PAR(2)-selective agonist. In addition, culture supernatants of P. gingivalis E8 (RgpA/RgpB double knockout) did not cause calcium response in PAR(2)-KNRK cells, evidencing the involvement of the arginine-specific cysteine proteases RgpA and RgpB in PAR(2) activation by P. gingivalis. Injection of P. gingivalis into mouse subcutaneous chambers provoked an increased proteolytic activity, which was inhibited by serine protease inhibitors. Fluids collected from chambers of P. gingivalis-injected mice were able to activate PAR(2) and this activation was inhibited by serine protease inhibitors. P. gingivalis inoculation into subcutaneous chambers of wild-type mice induced an inflammatory response that was inhibited by a serine protease inhibitor and was significantly reduced in PAR(2)-deficient mice. Finally, mice orally challenged with P. gingivalis developed alveolar bone loss, which was significantly reduced in PAR(2)-deficient mice at 42 and 60 days after P. gingivalis infection. We conclude that PAR(2) is activated on P. gingivalis infection, in which it plays an important role in the host inflammatory response.
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Affiliation(s)
- Marinella Holzhausen
- Pharmacology and Therapeutics, Faculty of Medicine, University of Calgary, 3330 Hospital Dr., NW Calgary, T2N 4N1 Alberta, Canada
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Karp JM, Tanaka TS, Zohar R, Sodek J, Shoichet MS, Davies JE, Stanford WL. Thrombin mediated migration of osteogenic cells. Bone 2005; 37:337-48. [PMID: 15964256 DOI: 10.1016/j.bone.2005.04.022] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2004] [Revised: 02/14/2005] [Accepted: 04/22/2005] [Indexed: 10/25/2022]
Abstract
Given that thrombin is ubiquitously expressed at sites of vascular injury, and that osteogenic cells express receptors for thrombin, we questioned whether thrombin could attract osteogenic cells to a bony wound. Using a scratch wound assay, thrombin stimulated a significant increase in migration of osteogenic cultures of primary marrow cells. This effect was dependent on thrombin proteolytic activity; however, thrombin was unable to stimulate the migration of a more differentiated marrow-derived osteogenic cell line. To better understand the role of thrombin in osteoprogenitor migration, we developed an osteoprogenitor migration assay that combines a modified Boyden chamber with a bone nodule assay. Primary cells that migrated through the transwell filter in the presence of thrombin formed significantly more bone nodules compared to the condition without thrombin. This was not due to proliferation or differentiation effects of thrombin. In contrast, thrombin was unable to stimulate an increase in the number of nodules for the more differentiated osteogenic cell line. Thus, our results suggest that thrombin exhibits differential motogenic effects on osteogenic cells depending on their differentiation state. The cell migration/bone nodule assay described here is the first assay that can be specifically used to examine the effects of factors on the migration of osteoprogenitor cells, particularly those derived from primary populations.
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Affiliation(s)
- Jeffrey M Karp
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, 4 Taddle Creek Road, Toronto, Ontario, Canada.
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Tancharoen S, Sarker KP, Imamura T, Biswas KK, Matsushita K, Tatsuyama S, Travis J, Potempa J, Torii M, Maruyama I. Neuropeptide release from dental pulp cells by RgpB via proteinase-activated receptor-2 signaling. THE JOURNAL OF IMMUNOLOGY 2005; 174:5796-804. [PMID: 15843583 DOI: 10.4049/jimmunol.174.9.5796] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Dental pulp inflammation often results from dissemination of periodontitis caused mostly by Porphyromonas gingivalis infection. Calcitonin gene-related peptide and substance P are proinflammatory neuropeptides that increase in inflamed pulp tissue. To study an involvement of the periodontitis pathogen and neuropeptides in pulp inflammation, we investigated human dental pulp cell neuropeptide release by arginine-specific cysteine protease (RgpB), a cysteine proteinase of P. gingivalis, and participating signaling pathways. RgpB induced neuropeptide release from cultured human pulp cells (HPCs) in a proteolytic activity-dependent manner at a range of 12.5-200 nM. HPCs expressed both mRNA and the products of calcitonin gene-related peptide, substance P, and proteinase-activated receptor-2 (PAR-2) that were also found in dental pulp fibroblast-like cells. The PAR-2 agonists, SLIGKV and trypsin, also induced neuropeptide release from HPCs, and HPC PAR-2 gene knockout by transfection of PAR-2 antisense oligonucleotides inhibited significantly the RgpB-elicited neuropeptide release. These results indicated that RgpB-induced neuropeptide release was dependent on PAR-2 activation. The kinase inhibitor profile on the RgpB-neuropeptide release from HPC revealed a new PAR-2 signaling pathway that was mediated by p38 MAPK and activated transcription factor-2 activation, in addition to the PAR-2-p44/42 p38MAPK and -AP-1 pathway. This new RgpB activity suggests a possible link between periodontitis and pulp inflammation, which may be modulated by neuropeptides released in the lesion.
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Affiliation(s)
- Salunya Tancharoen
- Department of Restorative Dentistry and Endodontology, Laboratory of Vascular Medicine, Kagoshima University Graduate School of Medical and Dental Science, Japan
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Holzhausen M, Spolidorio LC, Vergnolle N. Proteinase-activated receptor-2 (PAR2) agonist causes periodontitis in rats. J Dent Res 2005; 84:154-9. [PMID: 15668333 DOI: 10.1177/154405910508400209] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Proteinase-activated receptor-2 (PAR2) is a G-protein-coupled receptor that mediates cellular responses to extracellular proteinases. Since PAR2 is expressed by oral epithelial cells, osteoblasts, and gingival fibroblasts, where its activation releases interleukin-8, we hypothesized that PAR2 activation may participate in periodontal disease in vivo. We investigated the role of PAR2 activation in periodontal disease in rats. Radiographic and enzymatic (myeloperoxidase) analysis revealed that topical application of PAR2 agonist causes periodontitis but also exacerbates existing periodontitis, leading to significant alveolar bone loss and gingival granulocyte infiltration. Inhibition of matrix metalloproteinase (MMP) and cyclo-oxygenase (COX) decreased PAR2 agonist-induced periodontitis. More specifically, the overexpression of COX-1, COX-2, MMP-2, and MMP-9 in gingival tissues suggests that they are involved in PAR2-induced periodontitis. In conclusion, PAR2 agonist causes periodontitis in rats through a mechanism involving prostaglandin release and MMP activation. Inhibition of PAR2 may represent a novel approach to modulate host response in periodontitis.
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Affiliation(s)
- M Holzhausen
- Department of Pharmacology and Therapeutics, Faculty of Medicine, University of Calgary, Calgary, 3330 Hospital Drive, NW, Calgary, T2N 4N1, Alberta, Canada
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Holzhausen M, Spolidorio LC, Vergnolle N. Role of protease-activated receptor-2 in inflammation, and its possible implications as a putative mediator of periodontitis. Mem Inst Oswaldo Cruz 2005; 100 Suppl 1:177-80. [PMID: 15962119 DOI: 10.1590/s0074-02762005000900030] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Proteinase-activated receptor-2 (PAR2) belongs to a novel subfamily of G-protein-coupled receptors with seven-transmembrane domains. This receptor is widely distributed throughout the body and seems to be importantly involved in inflammatory processes. PAR2 can be activated by serine proteases such as trypsin, mast cell tryptase, and bacterial proteases, such as gingipain produced by Porphyromonas gingivalis. This review describes the current stage of knowledge of the possible mechanisms that link PAR2 activation with periodontal disease, and proposes future therapeutic strategies to modulate the host response in the treatment of periodontitis.
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Affiliation(s)
- M Holzhausen
- Department of Pharmacology and Therapeutics, Faculty of Medicine, University of Calgary, Alberta T2N 4N1, Canada
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Song SJ, Pagel CN, Pike RN, Mackie EJ. Studies on the receptors mediating responses of osteoblasts to thrombin. Int J Biochem Cell Biol 2005; 37:206-13. [PMID: 15381162 DOI: 10.1016/j.biocel.2004.04.026] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2004] [Revised: 04/22/2004] [Accepted: 04/28/2004] [Indexed: 11/26/2022]
Abstract
The serine protease thrombin stimulates proliferation in osteoblasts, but decreases alkaline phosphatase (ALP) activity, a marker of osteoblast differentiation. Three thrombin receptors have been identified, protease activated receptor (PAR)-1, PAR-3 and PAR-4; we have previously demonstrated that mouse osteoblasts express PAR-1 and PAR-4. The effect of thrombin on osteoblast proliferation and differentiation was studied to determine which of the thrombin receptors is responsible for the primary effects of thrombin. Primary mouse calvarial osteoblasts from PAR-1-null and wild-type mice, and synthetic peptides that specifically activate PAR-1 (TFFLR-NH2) and PAR-4 (AYPGKF-NH2) were used. Both the PAR-1-activating peptide and thrombin stimulated incorporation of 5-bromo-2'-deoxyuridine (two to four-fold, P < 0.001) and reduced alkaline phosphatase activity (approximately three-fold, P < 0.05) in cells from wild-type mice. The PAR-4-activating peptide, however, had no effect on either alkaline phosphatase activity or proliferation in these cells. Neither thrombin nor PAR-4-activating peptide was able to affect osteoblast proliferation or alkaline phosphatase activity in cells isolated from PAR-1-null mice. The results demonstrate that thrombin stimulates proliferation and inhibits differentiation of osteoblasts through activation of PAR-1. No other thrombin receptor appears to be involved in these effects.
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Affiliation(s)
- S J Song
- School of Veterinary Science, University of Melbourne, Parkville, Vic. 3010, Australia
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Steinhoff M, Buddenkotte J, Shpacovitch V, Rattenholl A, Moormann C, Vergnolle N, Luger TA, Hollenberg MD. Proteinase-activated receptors: transducers of proteinase-mediated signaling in inflammation and immune response. Endocr Rev 2005; 26:1-43. [PMID: 15689571 DOI: 10.1210/er.2003-0025] [Citation(s) in RCA: 364] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Serine proteinases such as thrombin, mast cell tryptase, trypsin, or cathepsin G, for example, are highly active mediators with diverse biological activities. So far, proteinases have been considered to act primarily as degradative enzymes in the extracellular space. However, their biological actions in tissues and cells suggest important roles as a part of the body's hormonal communication system during inflammation and immune response. These effects can be attributed to the activation of a new subfamily of G protein-coupled receptors, termed proteinase-activated receptors (PARs). Four members of the PAR family have been cloned so far. Thus, certain proteinases act as signaling molecules that specifically regulate cells by activating PARs. After stimulation, PARs couple to various G proteins and activate signal transduction pathways resulting in the rapid transcription of genes that are involved in inflammation. For example, PARs are widely expressed by cells involved in immune responses and inflammation, regulate endothelial-leukocyte interactions, and modulate the secretion of inflammatory mediators or neuropeptides. Together, the PAR family necessitates a paradigm shift in thinking about hormone action, to include proteinases as key modulators of biological function. Novel compounds that can modulate PAR function may be potent candidates for the treatment of inflammatory or immune diseases.
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Affiliation(s)
- Martin Steinhoff
- Department of Dermatology and Boltzmann Institute for Immunobiology of the Skin, University of Münster, von-Esmarch-Strasse 58, 48149 Münster, Germany.
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Okahashi N, Inaba H, Nakagawa I, Yamamura T, Kuboniwa M, Nakayama K, Hamada S, Amano A. Porphyromonas gingivalis induces receptor activator of NF-kappaB ligand expression in osteoblasts through the activator protein 1 pathway. Infect Immun 2004; 72:1706-14. [PMID: 14977979 PMCID: PMC356028 DOI: 10.1128/iai.72.3.1706-1714.2004] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Porphyromonas gingivalis, an important periodontal pathogen, is closely associated with inflammatory alveolar bone resorption, and several components of the organism such as lipopolysaccharides have been reported to stimulate production of cytokines that promote inflammatory bone destruction. We investigated the effect of infection with viable P. gingivalis on cytokine production by osteoblasts. Reverse transcription-PCR and real-time PCR analyses revealed that infection with P. gingivalis induced receptor activator of nuclear factor kappaB (NF-kappaB) ligand (RANKL) mRNA expression in mouse primary osteoblasts. Production of interleukin-6 was also stimulated; however, osteoprotegerin was not. SB20350 (an inhibitor of p38 mitogen-activated protein kinase), PD98059 (an inhibitor of classic mitogen-activated protein kinase kinase, MEK1/2), wortmannin (an inhibitor of phosphatidylinositol 3 kinase), and carbobenzoxyl-leucinyl-leucinyl-leucinal (an inhibitor of NF-kappaB) did not prevent the RANKL expression induced by P. gingivalis. Degradation of inhibitor of NF-kappaB-alpha was not detectable; however, curcumin, an inhibitor of activator protein 1 (AP-1), prevented the RANKL production induced by P. gingivalis infection. Western blot analysis revealed that phosphorylation of c-Jun, a component of AP-1, occurred in the infected cells, and an analysis of c-Fos binding to an oligonucleotide containing an AP-1 consensus site also demonstrated AP-1 activation in infected osteoblasts. Infection with P. gingivalis KDP136, an isogenic deficient mutant of arginine- and lysine-specific cysteine proteinases, did not stimulate RANKL production. These results suggest that P. gingivalis infection induces RANKL expression in osteoblasts through AP-1 signaling pathways and cysteine proteases of the organism are involved in RANKL production.
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Affiliation(s)
- Nobuo Okahashi
- Department of Oral Frontier Biology, Osaka University Graduate School of Dentistry, Osaka-Suita 565-0871, Japan.
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Abstract
Proteases acting at the surface of cells generate and destroy receptor agonists and activate and inactivate receptors, thereby making a vitally important contribution to signal transduction. Certain serine proteases that derive from the circulation (e.g., coagulation factors), inflammatory cells (e.g., mast cell and neutrophil proteases), and from multiple other sources (e.g., epithelial cells, neurons, bacteria, fungi) can cleave protease-activated receptors (PARs), a family of four G protein-coupled receptors. Cleavage within the extracellular amino terminus exposes a tethered ligand domain, which binds to and activates the receptors to initiate multiple signaling cascades. Despite this irreversible mechanism of activation, signaling by PARs is efficiently terminated by receptor desensitization (receptor phosphorylation and uncoupling from G proteins) and downregulation (receptor degradation by cell-surface and lysosomal proteases). Protease signaling in tissues depends on the generation and release of proteases, availability of cofactors, presence of protease inhibitors, and activation and inactivation of PARs. Many proteases that activate PARs are produced during tissue damage, and PARs make important contributions to tissue responses to injury, including hemostasis, repair, cell survival, inflammation, and pain. Drugs that mimic or interfere with these processes are attractive therapies: selective agonists of PARs may facilitate healing, repair, and protection, whereas protease inhibitors and PAR antagonists can impede exacerbated inflammation and pain. Major future challenges will be to understand the role of proteases and PARs in physiological control mechanisms and human diseases and to develop selective agonists and antagonists that can be used to probe function and treat disease.
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45
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Smith R, Ransjö M, Tatarczuch L, Song SJ, Pagel C, Morrison JR, Pike RN, Mackie EJ. Activation of protease-activated receptor-2 leads to inhibition of osteoclast differentiation. J Bone Miner Res 2004; 19:507-16. [PMID: 15040840 DOI: 10.1359/jbmr.0301248] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2003] [Revised: 09/12/2003] [Accepted: 10/08/2003] [Indexed: 11/18/2022]
Abstract
UNLABELLED PAR-2 is expressed by osteoblasts and activated by proteases present during inflammation. PAR-2 activation inhibited osteoclast differentiation induced by hormones and cytokines in mouse bone marrow cultures and may protect bone from uncontrolled resorption. INTRODUCTION Protease-activated receptor-2 (PAR-2), which is expressed by osteoblasts, is activated specifically by a small number of proteases, including mast cell tryptase and factor Xa. PAR-2 is also activated by a peptide (RAP) that corresponds to the "tethered ligand" created by cleavage of the receptor's extracellular domain. The effect of activating PAR-2 on osteoclast differentiation was investigated. MATERIALS AND METHODS Mouse bone marrow cultures have been used to investigate the effect of PAR-2 activation on osteoclast differentiation induced by parathyroid hormone (PTH), 1,25 dihydroxyvitamin D3 [1,25(OH)2D3], and interleukin-11 (IL-11). Expression of PAR-2 by mouse bone marrow, mouse bone marrow stromal cell-enriched cultures, and the RAW264.7 osteoclastogenic cell line was demonstrated by RT-PCR. RESULTS RAP was shown to inhibit osteoclast differentiation induced by PTH, 1,25(OH)2D3, or IL-11. Semiquantitative RT-PCR was used to investigate expression of mediators of osteoclast differentiation induced by PTH, 1,25(OH)2D3, or IL-11 in mouse bone marrow cultures and primary calvarial osteoblast cultures treated simultaneously with RAP. In bone marrow and osteoblast cultures treated with PTH, 1,25(OH)2D3, or IL-11, RAP inhibited expression of RANKL and significantly suppressed the ratio of RANKL:osteoprotegerin expression. Activation of PAR-2 led to reduced expression of prostaglandin G/H synthase-2 in bone marrow cultures treated with PTH, 1,25(OH)2D3, or IL-11. RAP inhibited PTH- or 1,25(OH)2D3-induced expression of IL-6 in bone marrow cultures. RAP had no effect on osteoclast differentiation in RANKL-treated RAW264.7 cells. CONCLUSION These observations indicate that PAR-2 activation inhibits osteoclast differentiation by acting on cells of the osteoblast lineage to modulate multiple mediators of the effects of PTH, 1,25(OH)2D3, and IL-11. Therefore, the role of PAR-2 in bone may be to protect it from uncontrolled resorption by limiting levels of osteoclast differentiation.
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Affiliation(s)
- Rosealee Smith
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
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46
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Abstract
The multifunctional serine protease thrombin has been shown to be a specific agonist for a variety of functional responses of cells including osteoblasts. The current study was conducted to determine if thrombin was capable of inhibiting apoptosis in osteoblasts, and if so, to examine the mechanism by which this occurred. Thrombin (20-100 nM) significantly inhibited apoptosis in serum-starved cultures of the human osteoblast-like Saos-2 cell line and cultures of primary osteoblasts isolated from mouse calvariae, as well as dexamethasone-treated primary mouse osteoblasts. Inhibition of serum deprivation-induced apoptosis was shown to require thrombin's specific proteolytic activity. Primary mouse osteoblasts were found to express two functional thrombin receptors, PAR-1 and PAR-4. Thrombin inhibited serum deprivation-induced apoptosis in osteoblasts isolated from PAR-1 null mice to the same degree as in osteoblasts isolated from wild-type mice. Treatment of serum-deprived osteoblasts, isolated from either PAR-1 null or wild-type mice, with a PAR-4-activating peptide failed to significantly inhibit apoptosis compared to the relevant control. Medium conditioned by thrombin-treated osteoblasts, in which thrombin had been inactivated, was able to inhibit serum deprivation-induced osteoblast apoptosis almost as well as thrombin itself. Blocking protein synthesis, by cycloheximide pretreatment of the conditioning cells, prevented this action. The ability of known osteoblast survival factors, such as transforming growth factor beta1, fibroblast growth factor-2, insulin-like growth factor-II, and interleukin-6, to inhibit serum deprivation-induced osteoblast apoptosis was also tested. None of these factors was able to inhibit serum deprivation-induced osteoblast apoptosis to the same extent as thrombin. The results presented here demonstrate that thrombin treatment of osteoblasts inhibits apoptosis induced either by dexamethasone or by serum deprivation. Furthermore, it does so independently of the known thrombin receptors by bringing about the synthesis and/or secretion of an unknown survival factor or factors, which then act in an autocrine fashion to inhibit apoptosis.
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MESH Headings
- Animals
- Apoptosis/drug effects
- Apoptosis/genetics
- Apoptosis/physiology
- Base Sequence
- Cells, Cultured
- DNA/genetics
- In Vitro Techniques
- Mice
- Mice, Knockout
- Osteoblasts/cytology
- Osteoblasts/drug effects
- Osteoblasts/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptor, PAR-1/deficiency
- Receptor, PAR-1/genetics
- Receptor, PAR-1/metabolism
- Receptor, PAR-2/genetics
- Receptor, PAR-2/metabolism
- Receptors, Proteinase-Activated/genetics
- Receptors, Proteinase-Activated/metabolism
- Thrombin/metabolism
- Thrombin/pharmacology
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Affiliation(s)
- Charles N Pagel
- School of Veterinary Science, University of Melbourne, Parkville, Victoria 3010, Australia.
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47
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Rohatgi T, Sedehizade F, Sabel BA, Reiser G. Protease-activated receptor subtype expression in developing eye and adult retina of the rat after optic nerve crush. J Neurosci Res 2003; 73:246-54. [PMID: 12836167 DOI: 10.1002/jnr.10643] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Protease-activated receptors (PARs), 7-transmembrane domain G protein-coupled receptors, are involved in tissue degeneration and repair upon injury. We demonstrate the expression of all four PAR subtypes in the postnatal eye and in retina of the adult rat by reverse transcription-polymerase chain reaction (RT-PCR). PAR-1 is regulated developmentally in the eye, with a decrease from P1, P9, to P16, whereas levels for PAR-2, PAR-3, and PAR-4 remain unchanged throughout. In the retina of the adult rat, PAR-1 is highly expressed, whereas PAR-2 and PAR-3 are moderately expressed, compared to low PAR-4 expression. To elucidate possible roles of PARs after trauma, we carried out semiquantitative RT-PCR analysis of expression of all 4 PAR subtypes, beginning 6 hr after partial optic nerve crush (ONC) in the adult rat until 3 weeks after the mild trauma. Levels of PAR mRNA for all four subtypes were upregulated as early as 6 hr after unilateral ONC, except PAR-3, which showed a delayed upregulation. PAR-1, PAR-3, and PAR-4 mRNA levels returned to almost basal levels at 3 weeks post-crush, whereas PAR-2 mRNA level was still high by the end of 3 weeks after crush. Although the lesion was unilateral, PAR mRNA expression in the contralateral, uninjured side was affected to levels almost comparable to those in the injured side. Previous studies have shown an increase in thrombin levels at the site of injury, retinal ganglion cell degeneration by necrosis and apoptosis, and PAR activation as consequences of nerve crush. PAR upregulation because of nerve crush in the mild trauma model could act as an effector of early cell death. Eventual return of receptor mRNA to basal levels is consistent with neuroprotection.
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Affiliation(s)
- T Rohatgi
- Institut für Neurobiochemie, Otto-von-Guericke-Universität Magdeburg, Medizinische Fakultät, Magdeburg, Germany
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48
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Gaça MDA, Zhou X, Benyon RC. Regulation of hepatic stellate cell proliferation and collagen synthesis by proteinase-activated receptors. J Hepatol 2002; 36:362-9. [PMID: 11867180 DOI: 10.1016/s0168-8278(01)00285-9] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND/AIMS Thrombin and MC tryptase, which are agonists for proteinase-activated receptors-1 and -2, respectively, are both increased in injured liver. We have examined if rat stellate cells express these receptors and if receptor agonists influence stellate cell activation. METHODS Expression of mRNA for proteinase activated receptors-1 and -2 were examined by RT-PCR and Northern blotting in lysates of cultured stellate cells and receptor protein examined by Western blotting. The effects of receptor agonists on cell proliferation and collagen synthesis were examined by 3H-thymidine and 3H-proline incorporation assays, respectively. RESULTS Rat stellate cells activated by culture on plastic showed a progressive increase in expression of proteinase-activated receptor-1 and -2 mRNA and proteinase-activated receptor-2 protein as they transformed to a myofibroblastic phenotype. Proteinase-activated receptor-1 agonists thrombin and the peptide SFFLRN, and proteinase-activated receptor-2 agonists tryptase and the peptide SLIGRL induced stellate cell proliferation and the rapid phosphorylation of 44 and 42 kDa mitogen-activated protein kinases. PD98059, an inhibitor of these kinases, inhibited this proliferative response. Both tryptase and SLIGRL increased collagen secretion by stellate cells. CONCLUSIONS This study indicates that the natural proteinase-activated receptor agonists thrombin and MC tryptase might sustain liver fibrosis by promoting stellate cell proliferation and collagen synthesis.
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Affiliation(s)
- Marianna D A Gaça
- Liver Research Group, University Division of Infection, Inflammation and Repair, Southampton General Hospital, SO16 6YD, Southampton, UK
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Chinni C, de Niese MR, Jenkins AL, Pike RN, Bottomley SP, Mackie EJ. Protease-activated receptor-2 mediates proliferative responses in skeletal myoblasts. J Cell Sci 2000; 113 Pt 24:4427-33. [PMID: 11082036 DOI: 10.1242/jcs.113.24.4427] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Protease-activated receptor-2 (PAR-2) is a G protein-coupled receptor that is cleaved by proteases within the N terminus, exposing a new tethered ligand that binds and activates the receptor. Activators of PAR-2 include trypsin and mast cell tryptase. Skeletal myoblasts are known to express PAR-1, a thrombin receptor. The current study was undertaken to determine whether myoblasts express PAR-2. Primary neonatal rat and mouse skeletal myoblast cultures were shown to express PAR-2 in polymerase chain reaction and immunocytochemical studies. Expression of PAR-2 was also demonstrated by immunohistochemistry in developing mouse skeletal muscle in vivo. Trypsin or a synthetic peptide corresponding to the rat PAR-2 tethered ligand caused a dose-dependent elevation in intracellular calcium in cultured rat myoblasts, with an EC(50) of 13 nM or 56 microM, respectively. Studies aimed at identifying the function of PAR-2 in myoblasts demonstrated no effect of the receptor-activating peptide on survival or fusion in serum-deprived myoblasts. The PAR-2-activating peptide did, however, stimulate proliferation of serum-deprived myoblasts. These results demonstrate that skeletal muscle cells express PAR-2, activation of which leads to stimulation of myoblast proliferation.
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Affiliation(s)
- C Chinni
- School of Veterinary Science, University of Melbourne, Parkville, Victoria 3010, Australia
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50
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Smith R, Jenkins A, Lourbakos A, Thompson P, Ramakrishnan V, Tomlinson J, Deshpande U, Johnson DA, Jones R, Mackie EJ, Pike RN. Evidence for the activation of PAR-2 by the sperm protease, acrosin: expression of the receptor on oocytes. FEBS Lett 2000; 484:285-90. [PMID: 11078894 DOI: 10.1016/s0014-5793(00)02146-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Proteinase-activated receptor-2 (PAR-2) is a member of a family of G-protein-coupled, seven-transmembrane domain receptors that are activated by proteolytic cleavage. The receptor is expressed in a number of different tissues and potential physiological activators identified thus far include trypsin and mast cell tryptase. Acrosin, a trypsin-like serine proteinase found in spermatozoa of all mammals, was found to cleave a model peptide fluorescent quenched substrate representing the cleavage site of PAR-2. This substrate was cleaved with kinetics similar to those of the known PAR-2 activators, trypsin and mast cell tryptase. Acrosin was also shown to induce significant intracellular calcium responses in Chinese hamster ovary cells stably expressing intact human PAR-2, most probably due to activation of the receptor. Immunohistochemical studies using PAR-2 specific antibodies indicated that the receptor is expressed by mouse oocytes, which suggests that acrosin may play additional role(s) in the fertilization process via the activation of PAR-2 on oocytes.
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Affiliation(s)
- R Smith
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia
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