Doi:10.1080/08910600410026355Periodontal Disease, Matrix Metalloproteinases andChemically Modified Tetracyclines From the Department of Periodontology, Faculty of Dentistry, University of Oslo, Oslo, Norway Correspondence to: Svein Steinsvoll, Sagvollveien 1, 2830 Raufoss, Norway. Tel.: / 47 61191481; Fax: /4761191481; E-mail: [email protected] Microbial Ecology in Health and Disease 2004; 16: 1 /7 Matrix metalloproteinases (MMPs) are crucial in the degradation of the main components in the extracellular matrix and thereby playimportant roles in cell migration, wound healing and tissue remodelling. MMPs have pathogenic roles in arthritis, periodontitis, hepatitis,glomerulonephritis, atherosclerosis and cancer cell invasion. MMPs are activators of pro-inflammatory mediators that occur in latent forms,such as interleukin (IL)-1b, membrane-bound tumour necrosis factor (TNF) and different MMPs. To regulate their action, MMPs aresecreted in latent, inactive pro-enzyme forms, with plasmin and other MMPs as likely activators. MMP activity is further modulated by thetissue inhibitors of metalloproteinases (TIMP-1, -2, -3 and -4), which partly control and stabilize MMPs. In normal steady-state tissues, onlylow levels of MMPs are detected intra- and extra-cellularly because MMPs are tightly regulated at the level of transcription and secretion. Ininflamed periodontal tissue, numbers of cells expressing MMPs are increased as compared with healthy gingival tissue. Recently, novel non-antimicrobial MMP-inhibitory effects of tetracyclines were discovered, and subsequently a panel of chemically modified non-antimicrobialtetracyclines (CMTs) was developed. This paper discusses these new drugs and their possible biological effects in periodontal disease.
PERIODONTAL INFLAMMATION participate in the tissue breakdown occurring in period- Accumulation of bacteria at the dentogingival margin induces gingival inflammation and may trigger periodontaldisease. The host generates inflammation adjacent to the PERIODONTAL DEGRADATION periodontal pocket as a defence against the microbial Matrix metalloproteinases (MMPs) are crucial in the threat. Leukocytes including plasma cells, lymphocytes, degradation of main components in extracellular matrix macrophages and neutrophils are known to infiltrate and thereby play important roles in cell migration, wound the gingival tissue (1) and have been studied in great healing and tissue remodelling (16 /18). MMPs have detail, but only modest attention has been given to mast pathogenic roles in arthritis, periodontitis, hepatitis, glo- cells (2). Yet, mast cells are important multifunctional cells merulonephritis, atherosclerosis and cancer cell invasion in the first line of defence against bacterial and parasitic (16 /23). MMPs are activators of pro-inflammatory media- infections (3 /7), and occur in numbers comparable to tors that occur in latent forms, such as interleukin (IL)-1b, macrophages in the inflamed periodontal lesion (8). Mast transforming growth factor-b1 (TGF-b1), membrane- cells can secrete a range of substances that regulate bound tumour necrosis factor (TNF)-a and different angiogenesis, tissue remodelling and wound healing, which MMPs (16 /18, 24, 25). To regulate their action, MMPs include both degradation and synthesis of tissue compo- are secreted in latent, inactive pro-enzyme forms, with nents (9). A recent study showed that the numbers of plasmin and other MMPs as likely activators (16 /18).
gingival mast cells are markedly increased in the gingival MMP activity is further modulated by the tissue inhibitors tissue of HIV-infected persons with periodontitis as com- of metalloproteinases (TIMP-1, -2, -3 and -4), which partly pared with HIV counterparts (8). The increase in mast cell control and stabilize MMPs (16 /18, 26). In normal steady- numbers was pronounced (10-fold) even in the early state tissues, only low levels of MMPs are detected intra- stages of HIV infection, indicating that this could be an and extra-cellularly because MMPs are tightly regulated at HIV-induced effect (8). As patients with HIV infection the level of transcription and secretion (16 /18). In inflamed display increased susceptibility to periodontitis (10 /15), periodontal tissue, numbers of cells expressing MMPs are there may be a link between mast cells and periodontal increased as compared with healthy gingival tissue (16, breakdown. We therefore wanted to explore whether mast 27 /30). It was recently shown that gingival mast cells cells have properties that indicate that they can directly strongly expressed MMP-1, MMP-2 and MMP-8, and to a # Taylor & Francis 2004. ISSN 0891-060X Microbial Ecology in Health and Disease Periodontitis, MMPs and CMTs lesser degree TIMP-1/-2 (31) (Figs. 1 and 2). Higher PERIODONTAL DISEASE AND CHEMICALLY numbers of MMP- and TIMP-positive mast cells were MODIFIED TETRACYCLINES (CMTS) detected in inflamed as compared with healthy gingiva. This Periodontal disease is the major cause of tooth loss in the indicates that mast cells are likely to play an important role adult population, characterized by destruction of the in inflammation and tissue degradation in periodontal collagen fibres and other matrix constituents of the gingiva, diseases (31).
periodontal ligament and alveolar bone. Although the Fig. 2. Microphotographs of double immunostaining of mast cell tryptase (in red) with (in green) TIMP-1 (a) and TIMP-2 (b) in a gingivalbiopsy from an HIV patient with CMP. Overlapping colours (double-stained) appear in yellow. Blue colour is nuclear staining with DAPI.
Single staining from the indicated field is displayed to the right for TIMP-1/TIMP-2 (in green) and mast cells (in red). (a) Left: TIMP-1-expressing mast cells below the oral gingival epithelium (yellow). Some intra-epithelial mast cells can also be seen (red cells). Right: Singleexposures show staining for TIMP-1 (TIMP-1) and mast cell tryptase (MC) separately. (b) Left: TIMP-2-expressing mast cells below thepocket epithelium (yellow). Right: Single exposures show staining for TIMP-2 (TIMP-2) and mast cell tryptase (MC) separately. Originalmagnification /4.
Fig. 1. Microphotographs of double immunostaining for mast cell tryptase (in red) with (in green) MMP-1 (a /d), MMP-2 (e, f), or MMP-8(g, h) in a biopsy from an HIV patient with chronic marginal periodontitis (CMP). Blue colour is nuclear staining with DAPI. Overlappingcolors (double-stained) appear in yellow. (a) MMP-1-producing mast cells (in yellow) subjacent to oral gingival epithelium. (b) Singleexposure of mast cell tryptase and (c) MMP-1. (d) Double exposure of (b) and (c), showing partial co-localization of MMP-1 and mast celltryptase (yellow). (e) MMP-2-producing mast cells below pocket epithelium (red cells with yellow spots). (f) Higher magnification of fieldindicated in (e). White broken lines indicate the lumen of two MMP-2-venules, and an arrow points to a probably emigrating MMP-2-cell. (g) Inflammatory cell infiltrate below the pocket epithelium, showing MMP-8 mast cells (yellow and orange cells). MMP-8 mast cellswere often found within the dense parts of inflammatory cell infiltrates. (h) MMP-8 mast cells were often seen close to blood vessels (whitebroken line /blood vessel lumen). Original magnifications: /40 (a, h), /60 (b /d), /25 (e), /100 (f), /20 (g).
Fig. 3. Potential outcomes of gingival and periodontal infection. As a first line of defence against infection, the host tries to preventmicroorganisms from colonizing the tissue (epithelial barriers, antibacterial substances in saliva). If immune exclusion is unsuccessful,microbes or their products may penetrate or invade gingival and periodontal tissues. This will induce immune elimination systems(phagocytosis, complement activation, generation of specific immune processes mediated by B and T cells). If the invading agents are clearedaway, the tissue will become healthy again. If clearance fails, chronic infection of the gingival or periodontal tissue ensues. This is a balanced(but dynamic) condition where the infection is restrained physically (encapsulation) and functionally (phagocytosis and bacterial cell lysis).
Pro- and anti-inflammatory agents are kept in balance and the disease remains non-progressive (gingivitis or quiescent periodontitis).
Periodically, however, the balance may be disturbed, either by increasing strength of the attack or diminished defence by the host, andprogressive loss of gingival and periodontal tissue may occur (active or necrotizing periodontitis). CMTs reduce the MMP activity, thegeneration of inflammatory cytokines such as IL-1, IL-6 and TNF, and the subsequent release of prostaglandins.
microflora, primarily the anaerobic gram-negative micro- pocket by mechanical debridement and can also involve the organisms that accumulate in the gingival crevice, initiate use of topical or systemic antibiotics as an adjunct. A novel this inflammatory disease in the gingival tissues, the approach currently gaining interest is the use of ‘host- connective tissue breakdown that occurs in this disease, modulating therapy', which attempts to supplement the and subsequently in the deeper periodontal tissues, is traditional antimicrobial treatment strategies with drugs mediated by excessive levels of activated MMPs (and other that (1) inhibit the production of inflammatory mediators, proteases such as serine proteases and neutrophilic elas- such as prostaglandins and pro-inflammatory cytokines, or tase), produced by host cells (e.g. neutrophils, macrophages, (2) block the production and activity of host-generated, mast cells, epithelial cells, endothelial cells, fibroblasts, tissue-destructive proteinases such as the MMPs (33).
osteoblasts, osteoclasts), overcoming the endogenous pro- teinase inhibitor (e.g. TIMPs, a2-macroglobulin) shield (32).
mediated bone resorption, are a third category of host- Treatment of periodontal disease has traditionally fo- modulating drugs that are currently being explored as cused on the reduction of bacterial ‘load' in the periodontal adjuncts in the treatment of periodontal disease; these Periodontitis, MMPs and CMTs Fig. 4. Biological roles of CMTs in inflammation and wound healing. In early phases of inflammation and at low concentrations, CMTs maymodulate integrin expression on endothelial cells (1). CMTs will counteract the effects of TGF-b1 being chemotactic for mast cells,monocytes, neutrophils and fibroblasts, and enhance expression of enzymes (e.g. matrix metalloproteinases) that are important forextravasation and migration in the extracellular matrix (2). In the inflamed area, increasing levels of TGF-b1 activate and stimulate theleukocytes to secrete pro-inflammatory cytokines and growth factors (3), and to further increase expression of surface molecules such asFcgRIII for more effective phagocytosis (4). As the leukocytes are activated they alter their TGF-b1 receptor expression and becomesusceptible to deactivation and growth arrest (5). Fibroblasts that early in inflammation produce collagenases are later induced by TGF-b1 todecrease their protease production. The fibroblasts are further stimulated to increase the production of protease inhibitors such as tissueinhibitor of metalloproteinase-1 (TIMP-1), plasminogen activator inhibitor-1 (PAI-1), and to synthesize matrix molecules (6). Finally, TGF-b1 is an IgA switch factor (7). Solid lines indicate pro-inflammatory effects while dashed lines indicate anti-inflammatory and wound healingeffects. CMTs will favour a shift of the local microenvironment towards an anti-inflammatory anabolic situation with matrix and collagendeposition, partly due to lower MMP activity and increased activity of MMP inhibitors and reduced activity of inflammatory cytokines (e.g.
IL-1, IL-6, TNF) and prostaglandins.
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Volume 2, Issue 2 (2014) 373-378 ISSN 2347 - 3258 International Journal of Advance Research and Innovation Fluoroquinolones-A New Definition of Antibiotics Nishant Verma *, a, K. K. Jha a, Rajesh Sharma a, Niraj K. Singh a, Ajai Kumar Singh b, Sachin Tyagi c, Umesh kumar d a Department of Pharmacy, T. M. College of Pharmacy, TMU, Moradabad, Uttar Pradesh, India b Department of Pharmaceutics, Gandhi College of Pharmacy, Karnal, Haryana, India c School of Pharmacy, Bharat Institute of Technology, Meerut, Uttar Pradesh, India d Translam Institute of Pharmaceutical Education & Research, Meerut, Uttar Pradesh, India
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