In vivo collagenase-2 (MMP-8) expression by human bronchial epithelial cells and monocytes/macrophages in bronchiectasis

Factors influencing the response to therapy in dogs with eosinophilic bronchopneumopathy

OBJECTIVES

Canine eosinophilic bronchopneumopathy (EBP) is a poorly understood disease characterized by chronic inflammation of the lower airways. To date, factors affecting the course of the disease are largely unknown. The objective of this study was to investigate the influence of clinical, laboratory, and environmental factors on therapeutic outcome in dogs with EBP.

MATERIAL AND METHODS

Environmental and housing conditions, course of disease, and response to treatment were evaluated using a standardized questionnaire for owners of 29 dogs diagnosed with EBP from 3 different veterinary referral centers in Germany. Data of diagnostic tests (hematology, radiographs, bronchoalveolar-lavage-fluid-(BALF) cytology) were retrospectively obtained from medical records. The influence of the different factors was assessed using Fisher's-exact-test and Mann-Whitney-U- or Kruskal-Wallis-test.

RESULTS

The proportion of neutrophilic granulocytes in BALF-cytology was significantly higher in dogs with persistent clinical signs compared to dogs that achieved clinical remission (p=0.029). Duration of clinical signs before treatment was significantly longer in dogs with persistent clinical signs (16±12 months) compared to dogs that achieved clinical remission (6±7 months) (p=0.017).

CONCLUSION

Early diagnosis and therapy have a decisive influence on the success of treatment.

CLINICAL RELEVANCE

Dogs with respiratory signs suspicious for EBP should be evaluated in a timely manner to increase the likelihood of clinical remission with an early start of therapy.

Neutrophil Extracellular Traps Are Found in Bronchoalveolar Lavage Fluids of Horses With Severe Asthma and Correlate With Asthma Severity

Asthma encompasses a spectrum of heterogenous immune-mediated respiratory disorders sharing a similar clinical pattern characterized by cough, wheeze and exercise intolerance. In horses, equine asthma can be subdivided into severe or moderate asthma according to clinical symptoms and the extent of airway neutrophilic inflammation. While severe asthmatic horses are characterized by an elevated neutrophilic inflammation of the lower airways, cough, dyspnea at rest and high mucus secretion, horses with moderate asthma show a milder neutrophilic inflammation, exhibit intolerance to exercise but no labored breathing at rest. Yet, the physiopathology of different phenotypes of equine asthma remains poorly understood and there is a need to elucidate the underlying mechanisms tailoring those phenotypes in order to improve clinical management and elaborate novel therapeutic strategies. In this study, we sought to quantify the presence of neutrophil extracellular traps (NETs) in bronchoalveolar lavage fluids (BALF) of moderate or severe asthmatic horses and healthy controls, and assessed whether NETs correlated with disease severity. To this end, we evaluated the amounts of NETs by measuring cell-free DNA and MPO-DNA complexes in BALF supernatants or by quantifying NETs release by BALF cells by confocal microscopy. We were able to unequivocally identify elevated NETs levels in BALF of severe asthmatic horses as compared to healthy controls or moderate asthmatic horses. Moreover, we provided evidence that BALF NETs release was a specific feature seen in severe equine asthma, as opposed to moderate asthma, and correlated with disease severity. Finally, we showed that NETs could act as a predictive factor for severe equine asthma. Our study thus uniquely identifies NETs in BALF of severe asthmatic horses using three distinct methods and supports the idea that moderate and severe equine asthma do not rely on strictly similar pathophysiological mechanisms. Our data also suggest that NETs represent a relevant biomarker, a putative driver and a potential therapeutic target in severe asthma disease.

Correlation between Peri-Implant Marginal Bone Loss Progression and Peri-Implant Sulcular Fluid Levels of Metalloproteinase-8

Objectives: The aim of this retrospective study was to analyze peri-implant marginal bone loss levels/rates and peri-implant sulcular fluid levels/rates of metalloproteinase-8 in three timeframes (6 months post-surgery—restoration delivery (T0)—and 6 (T6) and 24 (T24)-months post-loading) and to evaluate if there is a correlation between peri-implant sulcular fluid levels of metalloproteinase-8 and peri-implant marginal bone loss progression. Materials and Methods: Two cohorts of patients undergoing implant surgery between January 2017 and January 2019 were selected in this retrospective study. A total of 39 patients received 39 implants with a laser-microtextured collar surface, and 41 subjects received 41 implants with a machined/smooth surface. For each patient, periapical radiographs and a software package were used to measure marginal bone loss rates. Implant fluid samples were analyzed by an enzyme-linked immunosorbent assay (ELISA) test. The modified plaque index, probing depth, and bleeding on probing were also recorded. Results: High marginal bone rates at T24 were strongly associated with elevated rates between T0 and T6. The levels of metalloproteinase-8 were significantly more elevated around implants with marginal bone loss, in relation to implants without marginal bone loss. Marginal bone loss (MBL) rates at 24 months were associated with initial bone loss rates and initial levels of metalloproteinase-8. Conclusions: Peri-implant marginal bone loss progression is statistically correlated to peri-implant sulcular fluid levels of metalloproteinase-8. Moreover, the initial high levels of marginal bone loss and metalloproteinase-8 can be considered as indicators of the subsequent progression of peri-implant MBL: implants with increased marginal bone loss rates and metalloproteinase-8 levels at 6 months after loading are likely to achieve additional marginal bone loss values.

A robust classification-dependent multi-molecular modelling study on some biphenyl sulphonamide based MMP-8 inhibitors

Matrix metalloproteinases (MMPs) are a group of zinc and calcium-dependent endopeptidases, which contribute to different physiological and biological activities via extracellular matrix (ECM) degradation. Matrix metalloproteinase-8 (MMP-8) belongs to type-II collagenases of the MMP family that has contribution in several physiological disorders such as cardiovascular diseases, joint, renal, digestive and respiratory disorders as well as in cancer. In clinical study, MMP-8 is found to be associated with periodontal disease condition. Therefore, MMP-8 specific inhibitors should be developed to target these disorders. The biphenyl sulphonamide (BPS) moiety is one of the crucial structural characteristics found in several MMP-8 inhibitors. Here, different classification-based molecular modelling methods were used to explore the structural features that lead to the activity variation of a series of MMP-8 inhibitors possessing a BPS moiety. Our current classification-based structural analysis of these BPS-derived MMP-8 inhibitors was able to identify the importance of several structural features such as the tetrahydroisoquinoline and N-Boc pyridyl groups, which have positive influences on MMP-8 inhibition. This study was also reflected the importance of the zinc-binding groups (ZBGs) like the hydroxamate and phosphonate for potent and sub-nanomolar range MMP-8 inhibition, which may benefit the development of highly potent MMP-8 inhibitors.

Surface-bound matrix metalloproteinase-8 on macrophages: Contributions to macrophage pericellular proteolysis and migration through tissue barriers

Objective

MMP‐8 binds to surface‐bound tissue inhibitor of metalloproteinase‐1 (TIMP‐1) on PMNs to promote pericellular proteolysis during the development of inflammatory diseases associated with tissue destruction. Little is known about the biology of MMP‐8 in macrophages. We tested the hypotheses that: (1) MMP‐8 and TIMP‐1 are also expressed on the surface of activated macrophages, (2) surface‐bound MMP‐8 on macrophages promotes TIMP‐resistant pericellular proteolysis and macrophage migration through tissue barriers, and (3) MMP‐8 binds to surface‐bound TIMP‐1 on macrophages.

Methods

Surface MMP‐8 and TIMP‐1 levels were measured on human monocyte‐derived macrophages (MDM) and/or murine macrophages using immunostaining, biotin‐labeling, and substrate cleavage methods. The susceptibility of membrane‐bound Mmp‐8 on activated macrophages from wild‐type (WT) mice to TIMPs was measured. Migration of WT and Mmp‐8^−/− macrophages through models of tissue barriers in vitro and the accumulation of peritoneal macrophages in WT versus Mmp‐8^−/− mice with sterile peritonitis was compared. Surface levels of Mmp‐8 were compared on activated macrophages from WT and Timp‐1^−/− mice.

Results

Lipopolysaccharides and a cluster of differentiation 40 ligand increased surface MMP‐8 and/or TIMP‐1 staining and surface type I collagenase activity on MDM and/or murine macrophages. Activated Mmp‐8^−/− macrophages degraded less type I collagen than activated WT macrophages. The surface type‐I collagenase activity on WT macrophages was resistant to inhibition by Timp‐1. Peritoneal macrophage accumulation was similar in WT and Mmp‐8^−/− mice with sterile acute peritonitis. However, Mmp‐8^−/− macrophages migrated less efficiently through models of tissue barriers (especially those containing type I collagen) than WT cells. Activated WT and Timp‐1^−/− macrophages had similar surface‐bound Mmp‐8 levels.

Conclusions

MMP‐8 and TIMP‐1 are expressed on the surface of activated human MDM and murine macrophages, but Mmp‐8 is unlikely to bind to surface‐bound Timp‐1 on these cells. Surface‐bound MMP‐8 contributes to TIMP‐resistant monocyte/macrophage pericellular proteolysis and macrophage migration through collagen‐containing tissue barriers.

Extracellular matrix degradation by host matrix metalloproteinases in restorative dentistry and endodontics: An overview

Matrix metalloproteinases (MMPs) are a group of over 25 secreted and membrane-bound enzymes responsible for pericellular substrate degeneration. In response to injury, they play key roles in morphogenesis, wound healing, tissue repair and remodeling. They have been isolated from dentin, odontoblasts, pulp and periapical tissue. They play a major role in the formation of dentin matrix and secondary and tertiary dentin. These are also responsible for releasing dentinal growth factors. MMP family proteins elicit a dual role in the pathogenesis of inflammation, stimulating protective innate and/or adaptive immune functions, as well as tissue destruction. The main organic component of tooth structure is collagen, and MMPs that degrade collagen and the extracellular matrix have been implicated in the progression of dental caries, dental erosion as well as degradation of the hybrid layer. MMPs have also been shown to be active in pulpitis, and studies have shown that they can be used as diagnostic markers of pulpal and periapical inflammation. This review describes the role of MMPs in dental caries, dental erosion, bond stability as well as in pulpal and periapical inflammation.

Mechanisms of toxicity mediated by neutrophil and eosinophil granule proteins

Neutrophils and eosinophils are granulocytes which are characterized by the presence of granules in the cytoplasm. Granules provide a safe storage site for granule proteins that play important roles in the immune function of granulocytes. Upon granulocytes activation, diverse proteins are released from the granules into the extracellular space and contribute to the fight against infections. In this article, we describe granule proteins of both neutrophils and eosinophils able to kill pathogens and review their anticipated mechanism of antimicrobial toxicity. It should be noted that an excess of granules protein release can lead to tissue damage of the host resulting in chronic inflammation and organ dysfunction.

Adjunctive Antiseptic Irrigation of Periodontal Pockets: Effects on Microbial and Cytokine Profiles

To evaluate the effect of adjunctive antiseptic irrigation of periodontal pockets on microbial and cytokine profiles. Fifty-nine patients with severe periodontitis were allocated to one of three groups for scaling and root planing facilitated with different adjunctive antiseptics: 1% polyhexamethyleneguanidine phosphate (PHMG-P) (n = 19), 0.2% chlorhexidine (CHX) (n = 21) or distilled water (n = 19). Gingival crevicular fluid and subgingival bacterial samples were collected at baseline, and at 2 weeks, and 1 and 4 months. The levels of interleukin (IL)-1β, IL-8, IL-10, and IL-17A, matrix metalloproteinase (MMP)-8, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Fusobacterium nucleatum,Aggregatibacter actinomycetemcomitans, and Prevotella intermedia were determined. There were no intergroup differences in cytokine concentrations and bacterial counts at any follow-up, however, varying patterns were observed. In the PHMG-P and water groups IL-1β expression peaked at 2 weeks and then gradually declined. In all three groups, the dynamics of MMP-8 concentration were non-linear, increasing by 2 weeks and then declining to below baseline (p > 0.05). P. gingivalis and T. forsythia declined within the first month and increased thereafter, not regaining the baseline level. Adjunctive antiseptic treatment was associated with changes in biomarkers and bacterial counts in the course of the study. The effects of adjunctive antiseptic irrigation were limited in the applied protocol.

Tissue Inhibitor of Metalloproteinase-1 Promotes Polymorphonuclear Neutrophil (PMN) Pericellular Proteolysis by Anchoring Matrix Metalloproteinase-8 and -9 to PMN Surfaces

Matrix metalloproteinase (MMP)-8 and -9 released by degranulating polymorphonuclear cells (PMNs) promote pericellular proteolysis by binding to PMN surfaces in a catalytically active tissue inhibitor of metalloproteinases (TIMP)-resistant forms. The PMN receptor(s) to which MMP-8 and MMP-9 bind(s) is not known. Competitive binding experiments showed that Mmp-8 and Mmp-9 share binding sites on murine PMN surfaces. A novel form of TIMP-1 (an inhibitor of soluble MMPs) is rapidly expressed on PMN surfaces when human PMNs are activated. Membrane-bound TIMP-1 is the PMN receptor for pro- and active MMP-8 and -9 as shown by the following: 1) TIMP-1 is strikingly colocalized with MMP-8 and -9 on activated human PMN surfaces and in PMN extracellular traps; 2) minimal immunoreactive and active Mmp-8 or Mmp-9 are detected on the surface of activated Timp-1^-/- murine PMNs; and 3) binding of exogenous Timp-1 (but not Timp-2) to Timp-1^-/- murine PMNs reconstitutes the binding of exogenous pro-Mmp-8 and pro-Mmp-9 to the surface of Timp-1^-/- PMNs. Unlike full-length pro-Mmp-8 and pro-Mmp-9, mutant pro-Mmp proteins lacking the COOH-terminal hemopexin domain fail to bind to Mmp-8^-/-x Mmp-9^-/- murine PMNs. Soluble hemopexin inhibits the binding of pro-Mmp-8 and pro-Mmp-9 to Mmp-8^-/-x Mmp-9^-/- murine PMNs. Thus, the COOH-terminal hemopexin domains of pro-Mmp-8 and pro-Mmp-9 are required for their binding to membrane-bound Timp-1 on murine PMNs. Exposing nonhuman primates to cigarette smoke upregulates colocalized expression of TIMP-1 with MMP-8 and MMP-9 on peripheral blood PMN surfaces. By anchoring MMP-8 and MMP-9 to PMN surfaces, membrane-bound TIMP-1 plays a counterintuitive role in promoting PMN pericellular proteolysis occurring in chronic obstructive pulmonary disease and other diseases.

Comparison of rapid MMP-8 and interleukin-6 point-of-care tests to identify intra-amniotic inflammation/infection and impending preterm delivery in patients with preterm labor and intact membranes. J Matern Fetal Neonatal Med 2018;31:228-244. [PMID: 28081646 PMCID: PMC5769687 DOI: 10.1080/14767058.2017.1281904]

OBJECTIVE

Among patients presenting with preterm labor and intact membranes, those with intra-amniotic inflammation have adverse obstetrical and neonatal outcomes. The diagnosis of intra-amniotic inflammation can easily be made by detecting an elevated concentration of the cytokine interleukin (IL)-6 or the enzyme neutrophil collagenase, also known as matrix metalloproteinase (MMP)-8. The diagnostic performances of MMP-8 and IL-6 enzyme-linked immunosorbent assay tests are similar. Recently, a rapid test has become available for point-of-care determination of either MMP-8 or IL-6. The objectives of this study were to compare the diagnostic indices and predictive values between the rapid MMP-8 and IL-6 tests for the identification of intra-amniotic inflammation in patients with preterm labor and intact membranes.

MATERIALS AND METHODS

We performed a retrospective cohort study including 124 women with singleton pregnancies who presented with symptoms of preterm labor and underwent transabdominal amniocentesis for the evaluation of microbial invasion of the amniotic cavity (MIAC). MIAC was defined according to amniotic fluid culture results (aerobic and anaerobic bacteria as well as genital Mycoplasmas). Amniotic fluid white blood cell (WBC) counts were determined using a hemocytometer chamber. An elevated amniotic fluid MMP-8 concentration was assessed using Yoon's MMP-8 Check® (cutoff: 10 ng/mL). An elevated amniotic fluid IL-6 concentration was scored when there was a positive result for the lateral flow-based immunoassay (cutoff: ≥745 pg/mL and ≥1000 pg/mL). In order to objectively compare rapid MMP-8 and rapid IL-6 tests to identify intra-amniotic inflammation, an amniotic fluid WBC count of ≥50 cells/mm3 was used to define intra-amniotic inflammation.

RESULTS

(1) The rapid tests had the same sensitivity for the detection of intra-amniotic inflammation [85.7% (18/21) for all]; (2) the specificity of the rapid MMP-8 test was higher than that of the rapid IL-6 test (cutoff: 745 pg/mL) for the identification of intra-amniotic inflammation [72.8% (75/103) vs. 64.1% (66/103); p < 0.05]; and (3) there were no differences in the sensitivity and specificity between the rapid MMP-8 test and the rapid IL-6 test (cutoff:1000 pg/mL) in the identification of intra-amniotic inflammation. Of 13 patients with discrepant results between the rapid MMP-8 and rapid IL-6 tests, two had a positive MMP-8 but a negative rapid IL-6 test, and both delivered preterm - one within 24 h, and the other within 10 days - and both had acute histologic chorioamnionitis. On the other hand, there were 11 patients with a positive rapid IL-6 but a negative rapid MMP-8 result: 10 delivered preterm, 3 had acute histologic chorioamnionitis and 1 had subacute chorionitis.

CONCLUSION

We conclude that the rapid MMP-8 test has a better specificity than the rapid IL-6 (cutoff: 745 pg/mL) assay for the detection of intra-amniotic infection. Moreover, we observed that among patients who were not identified as having intra-amniotic infection or inflammation by the standard cultivation technique and amniotic fluid WBC count, those who had a positive MMP-8 rapid test delivered preterm and had acute histologic chorioamnionitis.

The in vivo Levels of Matrix Metalloproteinase-1 and -8 in Gingival Crevicular Fluid during Initial Orthodontic Tooth Movement

Orthodontic force induces biochemical responses in the periodontal ligament (PDL), but the matrix metalloproteinase (MMP)-dependent molecular mechanisms in orthodontically induced periodontal remodeling have remained unclear. Previous studies indicate that mechanical stress induces MMP-1 production in human PDL cells in vitro. We tested the hypothesis whether the in vivo levels, molecular forms, and degree of activation of MMP-1 and MMP-8 in gingival crevicular fluid (GCF) reflect an early stage of orthodontic tooth movement. Molecular forms of MMP-1 and MMP-8 were analyzed by Western blot, and MMP-8 levels by quantitative immunofluoro-metric assay (IFMA). The results showed that GCF MMP-8 levels for orthodontically treated teeth were significantly higher at 4-8 hrs after force application than before activation, and when compared with the control teeth (p < 0.05). Analysis of our data indicates that the cells within the periodontium are up-regulated to produce MMP-8, and the increased expression and activation of GCF MMP-8 reflect enhanced periodontal remodeling induced by orthodontic force.

Serum collagenase-2 and BMI levels in pregnant women with striae gravidarum

OBJECTIVE

Striae gravidarum is a form of scarring on the skin observed during pregnancy and can cause serious cosmetic problems. Striae gravidarum may be influenced by hormonal changes, although the etiology is not clear. The aim of this study was to investigate whether body mass index (BMI) and serum collagenase-2 levels in pregnant women are related to the development of striae gravidarum.

METHODS

Thirty pregnant women with striae, 30 pregnant women without striae, and 32 health controls were enrolled in the study.

RESULTS

BMI and serum collagenase-2 levels were measured in the participants.

CONCLUSION

Pregnant women with striae gravidarum had increased serum collagenase-2 and BMI levels when compared to pregnant women without striae gravidarum and healthy controls (P < 0.05). The increase in serum collagenase-2 levels was related to the development of striae gravidarum alone, or secondary to BMI increase.

MMP-8 Is Critical for Dexamethasone Therapy in Alkali-Burned Corneas Under Dry Eye Conditions

Our previous studies have shown that Dexamethasone (Dex) reduced the expression of matrix-metalloproteinases (MMPs -1,-3,-9,-13), IL-1β and IL-6, while it significantly increased MMP-8 mRNA transcripts in a concomitant dry eye and corneal alkali burn murine model (CM). To investigate if MMP-8 induction is responsible for some of the protective effects of Dex in CM, MMP-8 knock out mice (MMP-8KO) were subjected to the CM for 2 or 5 days and topically treated either with 2 μl of 0.1% Dexamethasone (Dex), or saline QID. A separate group of C57BL/6 mice were topically treated with Dex or BSS and received either 100 nM CAM12 (MMP-8 inhibitor) or vehicle IP, QD. Here we demonstrate that topical Dex treated MMP-8KO mice subjected to CM showed reduced corneal clarity, increased expression of inflammatory mediators (IL-6, CXCL1, and MMP-1 mRNA) and increased neutrophil infiltration at 2D and 5D compared to Dex treated WT mice. C57BL/6 mice topically treated with Dex and CAM12 IP recapitulated findings seen with MMP-8KO mice. These results suggest that some of the anti-inflammatory effects of Dex are mediated through increased MMP-8 expression. J. Cell. Physiol. 231: 2506-2516, 2016. © 2016 Wiley Periodicals, Inc.

Neutrophil proteolytic activation cascades: a possible mechanistic link between chronic periodontitis and coronary heart disease

Cardiovascular diseases are chronic inflammatory diseases that affect a large segment of society. Coronary heart disease (CHD), the most common cardiovascular disease, progresses over several years and affects millions of people worldwide. Chronic infections may contribute to the systemic inflammation and enhance the risk for CHD. Periodontitis is one of the most common chronic infections that affects up to 50% of the adult population. Under inflammatory conditions the activation of endogenous degradation pathways mediated by immune responses leads to the release of destructive cellular molecules from both resident and immigrant cells. Matrix metalloproteinases (MMPs) and their regulators can activate each other and play an important role in immune response via degrading extracellular matrix components and modulating cytokines and chemokines. The action of MMPs is required for immigrant cell recruitment at the site of inflammation. Stimulated neutrophils represent the major pathogen-fighting immune cells that upregulate expression of several proteinases and oxidative enzymes, which can degrade extracellular matrix components (e.g. MMP-8, MMP-9 and neutrophil elastase). The activity of MMPs is regulated by endogenous inhibitors and/or candidate MMPs (e.g. MMP-7). The balance between MMPs and their inhibitors is thought to mirror the proteolytic burden. Thus, neutrophil-derived biomarkers, including myeloperoxidase, may activate proteolytic destructive cascades that are involved in subsequent immune-pathological events associated with both periodontitis and CHD. Here, we review the existing studies on the contribution of MMPs and their regulators to the infection-related pathology. Also, we discuss the possible proteolytic involvement and role of neutrophil-derived enzymes as an etiological link between chronic periodontitis and CHD.

Role of matrix metalloproteinases in dental caries, pulp and periapical inflammation: An overview

Matrix metalloproteinases (MMPs) are a group of more than 25 secreted and membrane bound enzymes that represent class of enzymes responsible for degradation of pericellular substrates. They have been isolated from dentine, odontoblasts, pulp and periapical tissue. They play an important role in dentine matrix formation, modulating caries progression and secondary dentine formation. Earlier microbial proteolytic enzymes were believed to be responsible for degradation of dentine organic matrix, but lately the accumulated body of evidence suggests that MMPs have an important role in the process. During normal tissue modelling, differentiation during development, in modulating the cell behaviour, maintaining homeostasis and in numerous extracellular pathologic conditions, MMPs tends to be an equally important participant. Odontoblasts secrete some of the essential MMPs for both physiologic and pathologic conditions. MMPs also appear to be a participant in the process of reversible and irreversible pulpitis. Although they tend to have low expression and activity in adult tissues but at the onset of any destructive pathologic process, their production shoots up. They appear to have a significant presence during times of inflammation in the periapical region as well. We take a look at the various factors and evidence pointing towards the role of MMPs in the progression of caries, pulpal and periapical inflammation.

MMP-7, MMP-8, and MMP-9 in oral and cutaneous squamous cell carcinomas

OBJECTIVES

Oral squamous cell carcinoma (OSCC) and cutaneous squamous cell carcinoma (CSCC) are epithelial neoplasms, of which OSCC has a worse prognosis. Matrix metalloproteinases (MMPs) are involved in the initiation, invasion, metastasis, and defense of cancer. This study aimed to compare differences in MMP expression in these cancers.

STUDY DESIGN

Sixty-one patients with early-stage (T1-T2 N0 M0) cancers, of which 36 were OSCC and 25 CSCC, were enrolled into this study. Immunohistochemical staining was performed with MMP-7, MMP-8, and MMP-9 antibodies.

RESULTS

MMP-7 expression was stronger in OSCC than in CSCC, mainly in the invasive front. MMP-8 was absent and MMP-9 was mildly expressed in OSCC and CSCC cells. However, MMP-8 and MMP-9 were positive in peritumoral inflammatory cells in both cancers. In addition, MMP-7, MMP-8, and MMP-9 were not associated with the overall survival of patients with OSCC and CSCC patients.

CONCLUSIONS

The increased expression of MMP-7 in the invasive front may partly explain the aggressiveness of OSCC.

Common Matrix Metalloproteinases (MMP-8, -9, -25, and -26) Cannot Explain Dentigerous Cyst Expansion

OBJECTIVE

Mechanisms of the dentigerous cyst formation from the normal eruption follicle is unknown but disturbances in the proteolytic activity have been suspected, since the growth of these cysts is accompanied by local bone destruction. The aim of the present study was to evaluate the expression of matrix metalloproteinases (MMP) in human dental dentigerous cysts and healthy dental follicles.

MATERIALS AND METHODS

We studied 10 patients with dentigerous cysts and 10 healthy dental follicles from the lower jaw in respect to their immunoexpression of MMPs -8, -9, -25, and -26 and tissue inhibitor of metalloproteinases -1 (TIMP-1).

RESULTS

MMP-8 was expressed slightly more in cyst epithelium than in odontogenic epithelium of healthy controls dental follicle but the difference lacked statistical difference. Other MMPs and TIMP-1 did not differ regarding the studied specimens.

CONCLUSION

Differences in MMP expression cannot solely explain the cyst expansion suggesting the potential involvement of other osteolytic mechanisms.

Mononuclear phagocytes and airway epithelial cells: novel sources of matrix metalloproteinase-8 (MMP-8) in patients with idiopathic pulmonary fibrosis

Objectives

Matrix metalloproteinase-8 (MMP-8) promotes lung fibrotic responses to bleomycin in mice. Although prior studies reported that MMP-8 levels are increased in plasma and bronchoalveolar lavage fluid (BALF) samples from IPF patients, neither the bioactive forms nor the cellular sources of MMP-8 in idiopathic pulmonary fibrosis (IPF) patients have been identified. It is not known whether MMP-8 expression is dys-regulated in IPF leukocytes or whether MMP-8 plasma levels correlate with IPF outcomes. Our goal was to address these knowledge gaps.

Methods

We measured MMP-8 levels and forms in blood and lung samples from IPF patients versus controls using ELISAs, western blotting, and qPCR, and assessed whether MMP-8 plasma levels in 73 IPF patients correlate with rate of lung function decline and mortality. We used immunostaining to localize MMP-8 expression in IPF lungs. We quantified MMP-8 levels and forms in blood leukocytes from IPF patients versus controls.

Results

IPF patients have increased BALF, whole lung, and plasma levels of soluble MMP-8 protein. Active MMP-8 is the main form elevated in IPF lungs. MMP-8 mRNA levels are increased in monocytes from IPF patients, but IPF patients and controls have similar levels of MMP-8 in PMNs. Surprisingly, macrophages and airway epithelial cells are the main cells expressing MMP-8 in IPF lungs. Plasma and BALF MMP-8 levels do not correlate with decline in lung function and/or mortality in IPF patients.

Conclusion

Blood and lung MMP-8 levels are increased in IPF patients. Active MMP-8 is the main form elevated in IPF lungs. Surprisingly, blood monocytes, lung macrophages, and airway epithelial cells are the main cells in which MMP-8 is upregulated in IPF patients. Plasma and BALF MMP-8 levels are unlikely to serve as a prognostic biomarker for IPF patients. These results provide new information about the expression patterns of MMP-8 in IPF patients.

The immune response and its therapeutic modulation in bronchiectasis

Bronchiectasis (BC) is a chronic pulmonary disease with tremendous morbidity and significant mortality. As pathogen infection has been advocated as a triggering insult in the development of BC, a central role for the immune response in this process seems obvious. Inflammatory cells are present in both the airways as well as the lung parenchyma, and multiple mediators of immune cells including proteases and cytokines or their humoral products are increased locally or in the periphery. Interestingly, a defect in the immune system or suppression of immune response during conditions such as immunodeficiency may well predispose one to the devastating effects of BC. Thus, the outcome of an active immune response as detrimental or protective in the pathogenesis of BC may be dependent on the state of the patient's immunity, the severity of infection, and the magnitude of immune response. Here we reassess the function of the innate and acquired immunity in BC, the major sites of immune response, and the nature of the bioactive mediators. Furthermore, the potential link(s) between an ongoing immune response and structural alterations accompanying the disease and the success of therapies that can modulate the nature and extent of immune response in BC are elaborated upon.

Tet2 facilitates the derepression of myeloid target genes during CEBPα-induced transdifferentiation of pre-B cells

The methylcytosine hydroxylase Tet2 has been implicated in hematopoietic differentiation and the formation of myeloid malignancies when mutated. An ideal system to study the role of Tet2 in myelopoeisis is CEBPα-induced transdifferentiation of pre-B cells into macrophages. Here we found that CEBPα binds to upstream regions of Tet2 and that the gene becomes activated. Tet2 knockdowns impaired the upregulation of macrophage markers as well as phagocytic capacity, suggesting that the enzyme is required for both early and late stage myeloid differentiation. A slightly weaker effect was seen in primary cells with a Tet2 ablation. Expression arrays of transdifferentiating cells with Tet2 knockdowns permitted the identification of a small subset of myeloid genes whose upregulation was blunted. Activation of these target genes was accompanied by rapid increases of promoter hydroxy-methylation. Our observations indicate that Tet2 helps CEBPα rapidly derepress myeloid genes during the conversion of pre-B cells into macrophages.

Influence of MMP-8 promoter polymorphism in early osseointegrated implant failure

OBJECTIVE

Dental implants consist in the treatment of choice to replace tooth loss. The knowledge that implant loss tends to cluster in subsets of individuals may indicate that host immuneinflammatory response is influenced by genetic factors. In fact, genetic polymorphisms influence the osseointegration process. The objective of this study was investigate the possible relationship between C-799T polymorphism in matrix metalloproteinase 8 (MMP-8) gene and early implant failure in nonsmoker patients.

METHODS AND MATERIALS

Subjects were divided into two groups: control group (100 patients with one or more healthy implants) and test group (80 patients that had suffered one or more early implant failures). Genomic DNA from oral mucosa was amplified by PCR and analyzed by restriction endonucleases. The significance of the differences in observed frequencies of polymorphisms was assessed by Chi-square.

RESULTS

Statistical analysis shows that in the MMP-8 gene, the T allele in 76.25% in the test group and the T/T genotype, 63.75% in the same group, may predispose to early loss of implants osseointegrated.

CONCLUSION

These results suggest that polymorphism in the promoter region of MMP-8 gene is associated with early implant failure. This polymorphism can be a genetic marker to risk of implant loss.

CLINICAL RELEVANCE

The determination of this genetic pattern in osseointegration would enable the identification of individuals at higher risk to loss implant. Thus, genetic markers will be identified, contributing to an appropriate preoperative selection and preparation of strategies for prevention and therapy individualized to modulate the genetic markers and increase the success rate of treatments.

Human matrix metalloproteinases: an ubiquitarian class of enzymes involved in several pathological processes

Human matrix metalloproteinases (MMPs) belong to the M10 family of the MA clan of endopeptidases. They are ubiquitarian enzymes, structurally characterized by an active site where a Zn(2+) atom, coordinated by three histidines, plays the catalytic role, assisted by a glutamic acid as a general base. Various MMPs display different domain composition, which is very important for macromolecular substrates recognition. Substrate specificity is very different among MMPs, being often associated to their cellular compartmentalization and/or cellular type where they are expressed. An extensive review of the different MMPs structural and functional features is integrated with their pathological role in several types of diseases, spanning from cancer to cardiovascular diseases and to neurodegeneration. It emerges a very complex and crucial role played by these enzymes in many physiological and pathological processes.

Matrix metalloproteinase-8 expression in periodontal tissues surgically removed from diabetic and non-diabetic patients with periodontal disease

BACKGROUND

Although it is known that periodontal matrix metalloproteinase-8 (MMP-8) expression is associated with periodontal disease, the information concerning the periodontal MMP-8 expression in diabetic patients with periodontal disease is insufficient.

MATERIALS AND METHODS

Periodontal tissue specimens were collected from seven patients without periodontal disease and diabetes (Group 1), 15 patients with periodontal disease alone (Group 2) and 10 patients with both periodontal disease and diabetes (Group 3). The frozen sections were prepared and MMP-8 protein expression was detected using immunohistochemistry and quantified. For in vitro study, human U937 mononuclear cells were pre-exposed to normal or high glucose and then treated with lipopolysaccharide (LPS).

RESULTS

The nonparametric Kruskal-Wallis test showed that the difference in MMP-8 protein levels among the three groups were statistically significant (p = 0.003). Nonparametric analysis using Jonckheere-Terpstra test showed a tendency of increase in periodontal MMP-8 levels across Group 1 to Group 2 to Group 3 (p = 0.0002). In vitro studies showed that high glucose and LPS had a synergistic effect on MMP-8 expression.

CONCLUSION

Our current study showed an increasing trend in MMP-8 protein expression levels across patients without both periodontal disease and diabetes, patients with periodontal disease alone and patients with both diseases.

Altered expression of matrix metalloproteinases and their tissue inhibitors as possible contributors to corneal droplet formation in climatic droplet keratopathy

PURPOSE

Climatic droplet keratopathy (CDK) is an acquired corneal disease characterized by progressive scarring of the cornea. In several corneal diseases, matrix metalloproteinases (MMPs) are upregulated during the degradation of epithelial and stromal tissues. We investigated the levels, degree of activation and molecular forms of MMP-2, MMP-9, MMP-8 and MMP-13 and their tissue inhibitors TIMP-1 and TIMP-2 in tear fluid of patients with CDK.

METHODS

Seventeen CDK patients and 10 controls living in Argentine Patagonia received a complete eye examination, and MMPs and TIMP-1/2 were determined by immunofluorometric assay (IFMA), gelatin zymography and quantitative Western immunoblot analysis in tear samples.

RESULTS

The MMPs were detected mostly in their latent forms. The levels of MMP-9 and MMP-2 were found to be significantly elevated in CDK patients, whereas latent and active MMP-8 levels were significantly enhanced in controls. There was no significant difference in the level of MMP-13. TIMPs were found as part of complexes, and the TIMP-1 levels were significantly lower in patients than controls.

CONCLUSION

Elevated MMP-2 and MMP-9 levels have been implicated in the failure of corneal re-epithelialization, and enhanced MMP-2 and MMP-9 levels in CDK patients suggest that these MMPs may play a role in corneal scarring in CDK. Elevated levels of MMP-8 suggest a defensive role for this MMP in inflammatory reactions associated with recurring corneal traumas. Decreased expression of TIMP-1 in CDK patients suggest deficient antiproteolytic shield likely to render the corneas of CDK patients vulnerable to enhanced MMPs. Overall, these data suggest a mechanistic link between MMPs and TIMP-1 level in cornea and tears with corneal scarring in CDK.

Matrix metalloproteinase8 has a central role in inflammatory disorders and cancer progression

The predominant role of matrix metalloproteinase 8 in extracellular matrix turnover, modulation of inflammatory responses and other physiological processes is well documented. Several recent studies highlight the involvement of MMP8 in a wide range of pathologies. This review will shed light on the putative role of MMP8 as a drug target or disease marker in some inflammatory disorders and in cancer progression.

Expression of matrix metalloproteases by fibrocytes: possible role in migration and homing

RATIONALE

Fibrocytes are progenitor cells characterized by the simultaneous expression of mesenchymal, monocyte, and hematopoietic stem cell markers. We previously documented their presence in lungs of patients with idiopathic pulmonary fibrosis. However, the mechanisms involved in their migration, subsequent homing, and local role remain unclear. Matrix metalloproteinases (MMPs) facilitate cell migration and have been implicated in the pathogenesis of pulmonary fibrosis.

OBJECTIVES

To evaluate the expression and role of matrix metalloproteinases in human fibrocytes.

METHODS

Fibrocytes were purified from CD14(+) monocytes and cultured for 8 days; purity of fibrocyte cultures was 95% or greater as determined by flow cytometry. Conditioned media and total RNA were collected and the expression of MMP-1, MMP-2, MMP-7, MMP-8, and MMP-9 was evaluated by real-time polymerase chain reaction. Protein synthesis was examined using a Multiplex assay, Western blot, fluorescent immunocytochemistry, and confocal microscopy. MMP-2 and MMP-9 enzymatic activities were evaluated by gelatin zymography. Migration was assessed using collagen I-coated Boyden chambers. Stromal cell-derived factor-1α and platelet-derived growth factor-B were used as chemoattractant with or without a specific MMP-8 inhibitor.

MEASUREMENTS AND MAIN RESULTS

Fibrocytes showed gene and protein expression of MMP-2, MMP-9, MMP-8, and MMP-7. MMP-2 and MMP-9 enzymatic activities were also demonstrated by gelatin zymography. Likewise, we found colocalization of MMP-8 and MMP-7 with type I collagen in fibrocytes. Fibrocyte migration toward platelet-derived growth factor-B or Stromal cell-derived factor-1α in collagen I-coated Boyden chambers was significantly reduced by a specific MMP-8 inhibitor.

CONCLUSIONS

Our findings reveal that fibrocytes express a variety of MMPs and that MMP-8 actively participates in the process of fibrocyte migration.

MMP-8 promotes polymorphonuclear cell migration through collagen barriers in obliterative bronchiolitis

Increased levels of MMP-8 (neutrophil collagenase) have been reported in OB, but the biological role of MMP-8 in OB is not known. MMP-8 is an interstitial collagenase highly expressed by polymorphonuclear leukocytes, which are prominent in early OB. Here, we show that MMP-8 promotes migration of PMNs through the collagen-rich matrix in a mouse heterotopic airway transplant model of OB. Overall, MMP-8(-/-) mice had significantly fewer PMNs in the airway lumen 2 and 14 days post-transplantation, and the percentage of PMNs traversing the matrix to the lumen was decreased markedly in the MMP-8(-/-) compared with WT mice at 14 days. There were significantly more PMNs outside of the lumen in the ECM in the MMP-8(-/-) mice compared with WT mice. In vitro, significantly fewer MMP-8(-/-) PMNs migrated through 3D cross-linked collagen gels than WT PMNs. MMP inhibitor GM6001 was also able to impede migration of WT PMNs through collagen gels. The decreased migration was likely a result of pericollagenase activity of MMP-8, as WT PMNs expressing MMP-8 were not able to migrate effectively through collagen that was resistant to the collagenase. Protection from OB was seen in the MMP-8(-/-) mice, as the airway lumen had significantly less obliteration and collagen deposition, suggesting that MMP-8 plays an important role in the pathogenesis of OB.

Exhaled breath condensate MMP-9 levels in children with bronchiectasis

Bronchiectasis (BE) is still an important cause of chronic supurative respiratory diseases in developing countries. Neutrophil-derived proteases such as neutrophil elastase and matrix metalloproteases (MMPs) are implicated in causing airway damage in chronic pulmonary disease. In this study, we aimed to evaluate the MMP-9 and its natural tissue inhibitors of metalloproteinases (TIMP-1) levels utilizing the exhaled breath condensate (EBC) method and their relationship with radiological findings and pulmonary functions in children with BE.Thirty-eight children with BE and 12 healthy children were included: Group 1 (cystic fibrosis [CF] BE), Group 2 (non-CF BE), Group 3 (control group). High-resolution computerized tomography (HRCT) scores were calculated according to the anatomic extent of BE. Pulmonary function tests were performed, and MMP-9 and TIMP-1 levels in EBC were analyzed by ELISA.Exhaled breath condensate MMP-9 level was 48.9 +/- 26.8 ng/ml for Group 1, and for Group 2, 42.8 +/- 18.1 ng/ml; and for Group 3, 30 +/- 3.7 ng/ml. Although no statistically significant difference was found between the Groups 1 and 2, a significant difference was detected between these groups and controls. No statistically significant difference was found in TIMP-1 levels regarding all groups. EBC MMP-9 levels were inversely correlated with pulmonary functions test, and positively with HRCT scores and annual number of pulmonary infections.In conclusion, this study showed that EBC of children with both CF BE and non-CF BE contained higher levels of MMP-9 in comparison to controls. We suggest that EBC MMP-9 level may be a useful marker of airway injury in patients with BE however prospective studies are needed.

Placenta-derived fetal specific mRNA is more readily detectable in maternal plasma than in whole blood

BACKGROUND

Placental mRNA was detected in maternal whole blood, raising the possibility of using maternal blood for noninvasive prenatal diagnosis. We investigated fetal mRNA detection in maternal whole blood and determined if it offered advantages over maternal plasma analysis.

METHODOLOGY

The concentrations of placental expressed genes, CSH1, KISS1, PLAC4 and PLAC1 in plasma and whole blood from healthy pregnant and non-pregnant individuals were compared by real-time quantitative reverse-transcriptase polymerase chain reaction analysis. Their fetal specificity was investigated by comparing the transcript concentrations in pre- and post-delivery samples and through SNP genotyping by matrix-assisted laser-desorption and ionization time-of-flight mass spectrometry. The gene expression profiles of pregnant and non-pregnant whole blood were investigated by microarray analysis. Upregulated genes in pregnant whole blood were selected for further quantitative analysis.

PRINCIPAL FINDINGS

The concentrations of the four transcripts were significantly higher in third trimester maternal whole blood than corresponding plasma without significant correlations. KISS1, PLAC4 and PLAC1 were detected in non-pregnant whole blood but not plasma. The transcripts remained detectable in some postpartum whole blood samples. The PLAC4 mRNA in maternal plasma showed fetal genotype while that in corresponding whole blood indicated both fetal and maternal contributions. Microarray analysis revealed upregulation of genes involved in neutrophil functions in pregnant whole blood including DEFA4, CEACAM8, OLFM4, ORM1, MMP8 and MPO. Though possibly pregnancy-related, they were not pregnancy-specific as suggested by the lack of post-delivery reduction in concentrations.

CONCLUSIONS

Maternal plasma is preferred over maternal whole blood for placenta-derived fetal RNA detection. Most studied 'placental' mRNA molecules in maternal whole blood were of maternal origin and might be derived from processes such as 'illegitimate transcription'.

Matrix metalloproteases in bronchoalveolar lavage fluid of patients with type III Pseudomonas aeruginosa pneumonia

OBJECTIVES

In patients with ventilator-associated pneumonia (VAP), Pseudomonas aeruginosa type III (TTSS) secreting isolates have been linked to poor clinical outcomes. Differential expression of matrix metalloproteinases (MMPs) induced by type III effector proteins may herald an irreversible lung injury.

METHODS

Serial bronchoalveolar lavage fluids collected from 41 patients with P. aeruginosa at onset of VAP, day 4, and day 8 after antibiotic therapy were assayed for MMP-8, MMP-9, tissue inhibitor of metalloproteinase-1 (TIMP-1), and alpha-2 macroglobulin levels.

RESULTS

At the onset of VAP, isolates secreting ExoU had the highest MMP-9 levels. The response to antimicrobial therapy showed a differential drop in MMPs with significant decrease in MMP-8 and MMP-9 levels on days 4 and 8 in patients with TTSS(-) compared to TTSS(+) phenotype. The ratio of MMP-9/TIMP-1 was significantly associated with alpha-2 macroglobulin at end of therapy (r=0.4, p=0.02). Patients who survived had a lower MMP-9/TIMP-1 ratio than those who died (p=0.003).

CONCLUSIONS

VAP linked to P. aeruginosa Type III phenotype portrays a divergent antibiotic treatment response in regards to the concentrations of metalloproteinases in the alveolar space. The imbalance between MMP-9 and TIMP-1 may determine the intensity of alveolocapillary damage and ultimate outcome of P. aeruginosa VAP.

Matrix metalloproteinase activity in pediatric acute lung injury

Pediatric Acute Lung Injury (ALI) is associated with a high mortality and morbidity, and dysregulation of matrix metalloproteinases (MMPs) may play an important role in the pathogenesis and evolution of ALI. Here we examined MMP expression and activity in pediatric ALI compared with controls. MMP-8, -9, and to a lesser extent, MMP-2, -3, -11 and -12 were identified at higher levels in lung secretions of pediatric ALI patients compared with controls. Tissue Inhibitor of Matrix metalloproteinase-1 (TIMP-1), a natural inhibitor of MMPs was detected in most ALI samples, but MMP-9:TIMP-1 ratios were high relative to controls. In subjects who remained intubated for >or=10 days, MMP-9 activity decreased, with > 80% found in the latent form. In contrast, almost all MMP-8 detected at later disease course was constitutively active. Discriminating MMP-9:TIMP-1 ratios were found in those who had a prolonged ALI course. These results identify a specific repertoire of MMP isoforms in the lung secretions of pediatric ALI patients, and demonstrate inverse changes in MMPs -8 and -9 with protracted disease.

Local and systemic responses in matrix metalloproteinase 8-deficient mice during Porphyromonas gingivalis-induced periodontitis

Periodontitis is a bacterium-induced chronic inflammation that destroys tissues that attach teeth to jaw bone. Pathologically excessive matrix metalloproteinase 8 (MMP-8) is among the key players in periodontal destruction by initiating type I collagen degradation. We studied MMP-8 in Porphyromonas gingivalis-induced periodontitis by using MMP-8-deficient (MMP8(-/-)) and wild-type (WT) mice. Alveolar bone loss, inflammatory mediator expression, serum immunoglobulin, and lipoprotein responses were investigated to clarify the role of MMP-8 in periodontitis and systemic inflammatory responses. P. gingivalis infection induced accelerated site-specific alveolar bone loss in both MMP8(-/-) and WT mice relative to uninfected mice. The most extensive bone degradation took place in the P. gingivalis-infected MMP8(-/-) group. Surprisingly, MMP-8 significantly attenuated (P < 0.05) P. gingivalis-induced site-specific alveolar bone loss. Increased alveolar bone loss in P. gingivalis-infected MMP8(-/-) and WT mice was associated with increase in gingival neutrophil elastase production. Serum lipoprotein analysis demonstrated changes in the distribution of high-density lipoprotein (HDL) and very-low-density lipoprotein (VLDL) particles; unlike the WT mice, the MMP8(-/-) mice underwent a shift toward a smaller HDL/VLDL particle sizes. P. gingivalis infection increased the HDL/VLDL particle size in the MMP8(-/-) mice, which is an indicator of lipoprotein responses during systemic inflammation. Serum total lipopolysaccharide activity and the immunoglobulin G-class antibody level in response to P. gingivalis were significantly elevated in both infected mice groups. Thus, MMP-8 appears to act in a protective manner inhibiting the development of bacterium-induced periodontal tissue destruction, possibly through the processing anti-inflammatory cytokines and chemokines. Bacterium-induced periodontitis, especially in MMP8(-/-) mice, is associated with systemic inflammatory and lipoprotein changes that are likely involved in early atherosclerosis.

Human beta-defensin-1 and -2 and matrix metalloproteinase-25 and -26 expression in chronic and aggressive periodontitis and in peri-implantitis

OBJECTIVE

Aberrant matrix metalloproteinase (MMP) and human beta-defensin (HBD) functions have been found in inflammatory diseases. The objectives of this study were to investigate the immunolocalisation, mRNA expression and molecular forms of MMP-25, MMP-26, HBD-1 and HBD-2 in chronic and aggressive periodontitis and in peri-implantitis. The expression of MMP-25 by cultured human plasmacytoma cells and macrophages, and the effects of MMP-26 and Porphyromonas gingivalis trypsin-like proteinase on HBD-1 and -2 were also studied.

DESIGN

Immunohistochemistry, immunofluorescent analysis, reverse transcriptase polymerase chain reaction and immunoblotting were used to assess localisation, mRNA expression and molecular forms of MMP-25, MMP-26, HBD-1 and HBD-2. HBD degradation by MMP-26 and P. gingivalis proteinase was studied by sodium dodecyl sulphate-polyacrylamide gel electrophoresis.

RESULTS

MMP-25 was present in plasma cells and polymorphonuclear leucocytes, and MMP-26 was present in oral and sulcular basement membrane zones. HBD-1 was distributed perivasculary in gingival connective tissue and in oral and sulcular epithelium, and HBD-2 was found to a lesser extent in the perivascular space. Low MMP-25, MMP-26, HBD-1 and HBD-2 mRNA expression was found. Immunoblot revealed 29-57-kDa MMP-25 in myeloma cell lysates, but not in macrophages, and partly activated MMP-25 and -26 in diseased gingival crevicular fluid and peri-implant sulcular fluid. P. gingivalis trypsin-like proteinase degraded HBD-1 and -2.

CONCLUSIONS

Both MMP-25 and -26 were expressed more strongly in extensively inflamed gingiva compared with healthy gingiva. The expression of HBD-1 was stronger than that of HBD-2 in periodontitis and peri-implantitis. De-novo expression of MMP-25 and -26 is associated with periodontal and peri-implant inflammation. Furthermore, P. gingivalis trypsin-like proteinase, but not MMP-26, can degrade HBD-1 and -2, which could lead to a weakened innate immune response.

Collagenase and surgical disease

Collagen types I, II, and III are the most abundant extracellular matrix (ECM) proteins. Collagenase is a member of the matrix metalloproteinase (MMP) family of enzymes, and is the principal enzyme involved with collagen degradation. Cellular-ECM interactions are vitally important to tissue structure and function. In this review, we summarize recent work that highlights the role of collagenase in ECM remodeling and repair, and further report that alterations of collagenase expression, function, and/or regulation are found in many diverse disease states, including aortic aneurysms, tumor invasiveness and their metastases, and hernias. Collagenase is intimately involved in many surgical diseases, and represents a potential target for therapy.

Lack of association between matrix metalloproteinase 8 promoter polymorphism and bronchiectasis in Koreans

The observation that human matrix metalloproteinase (MMP)-8 is over-expressed in ectatic bronchi in patients with bronchiectasis suggests that polymorphisms altering the expression of MMP-8 may contribute to the susceptibility to development of bronchiectasis. We evaluated the association between the presence of bronchiectasis in a Korean population and two single nucleotide polymorphisms (SNPs) (-799C/ T and -381A/G) on the promoter region of the MMP-8 gene that are reported to alter the promoter activity and thereby the gene expression. Genotyping through polymerase chain reaction (PCR) and subsequent automatic sequencing was done in 167 patients with bronchiectasis and their age-, sex-matched healthy controls to reveal that only -799C/T is polymorphic among Koreans. In the patient group with bronchiectasis, the frequency of -799C/C, C/T, and T/T genotypes were 41.9%, 49.7%, and 8.4%, respectively. A similar distribution was observed in the control group: C/C (49.7%), C/T (43.1%), and T/T (7.2%) (p=0.36). In subgroup analysis, no significant difference was observed among the patients according to; the extent of disease (p=0.76), colonization of microorganisms (p=0.56), or association of mycobacteria (p=0.17). From these results, we conclude that -799C/T on the promoter region of MMP-8 lacks association with development of bronchiectasis in Koreans.

Lung transplant metalloproteinase levels are elevated prior to bronchiolitis obliterans syndrome

Parenchymal disease in the allograft lung is associated with interstitial remodeling believed to be mediated by matrix metalloproteinases (MMPs). Recent studies suggest high levels of MMP-9 are associated with bronchiolitis obliterans syndrome (BOS) in lung transplant recipients. Since BOS occurs late in the posttransplant period and may be preceded by episodes of acute rejection or infection, which are associated with interstitial remodeling, we examined MMP profiles in allograft bronchoalveolar lavage (BAL) fluid in the early posttransplant period (preceding BOS). Gelatin zymography, protein array analysis and specific ELISA on BAL fluids from transplanted lungs indicated that MMP-8, MMP-9 and TIMP-1 were strongly expressed in allograft BAL fluid from stable patients, or those with infection or rejection compared to BAL fluid from normal volunteers. Elevated expression of MMP-8, MMP-9 and TIMP-1 occurred early, and was sustained for the 3.2 years covered in this study. Elevations of MMP-8, MMP-9 and TIMP-1 in the first 2 years posttransplant appear to be associated with lung transplantation itself, and not infection or rejection. These data suggest that ongoing and clinically silent MMP activity could perpetuate progressive disease in the allograft lung.

Influence of early neutrophil depletion on MMPs/TIMP-1 balance in bleomycin-induced lung fibrosis

Pulmonary fibrosis is characterized by excessive deposition of extracellular matrix in interstitium resulting in respiratory failure associated with inflammation showing mainly neutrophil (PMN) recruitment. The turn over of extracellular matrix is partially regulated by proteases such as metalloproteinases (MMPs) and their inhibitors (TIMPs). We investigated the impact of PMN depletion on the MMP/TIMP-1 imbalance and the development of fibrosis in mice induced by bleomycin (0.3 mg/mouse). Administration of 200 microL of rabbit anti-mouse PMN antibody i.p. blunted the neutrophil influx detected in BAL and in whole blood one day after bleomycin administration. At day(14), hydroxyproline content was increased both in anti-PMN treated and control mice, without any difference between groups. At day one, bleomycin elicited a raise in pro-MMP-9 level in BAL that was significantly attenuated in anti-PMN depleted mice, whereas TIMP-1 and MMP-2 release were similar in both groups at day(1) and day(14). Higher RNA levels were observed in PMN-treated mice at day(1) for MMP-9 and MMP-2 and at day(14) for MMP-2 only. At day(14), bleomycin elicited a raise of TIMP-1 protein and RNA levels regardless of anti-PMN treatment, whereas MMP-9 returned to basal level. Bleomycin enhanced MMP-8 level in BAL at day(14) only for the control group. The amount of MMP-8 was more important in BAL from anti-PMN treated mice than in control mice at day(1) and day(14). PMN-depletion and the associated modifications in pro-MMP-9/TIMP-1 imbalance in lung during the early inflammatory phase do not alter susceptibility to bleomycin-induced pulmonary fibrosis.

Matrix metalloproteinase-7, -8, -9, -25, and -26 and CD43, -45, and -68 cell-markers in HIV-infected patients' saliva and gingival tissue

BACKGROUND

Matrix metalloproteinases (MMPs) process the extracellular matrix and act in tissue remodelling in many physiological and pathological conditions. Certain MMPs can also exert protective anti-inflammatory properties. The levels and expression of MMPs and tissue inhibitors of MMPs (TIMPs) in saliva and gingival tissues of human immunodeficiency virus-seropositive (HIV+) patients are unclear.

METHODS

Enzyme-linked immunosorbent assay methods and Western blots were used to study levels and molecular forms of MMP-7, -8, -9, -25, and -26 and TIMP-1 from salivary samples of HIV+ patients (n = 55) and healthy controls (n = 10). The expression of MMPs was also studied by immunohistochemical means in gingival tissue specimens (n = 11, HIV+ patients; n = 10, healthy controls).

RESULTS

The HIV+ patients' MMP-8 levels in saliva were statistically significantly higher only in the acquired immunodeficiency syndrome (AIDS)-phase. MMP-9 levels in ASX- and AIDS-phases showed increased expression. TIMP-1 levels were significantly decreased in lymphadenopathy syndrome (LAS)- and AIDS-related complex (ARC)-phases, while MMP-8/TIMP-1 and MMP-9/TIMP-1 molar ratios were increased in all phases in comparison with controls. The molecular forms of MMP-7, -25, and -26 were different between patients and controls as assessed by Western blot. Immunohistochemical studies showed slightly enhanced MMP-7, -8, -9, -25, and -26 staining in HIV+ gingival tissue samples in comparison with controls.

CONCLUSIONS

This study confirmed and further demonstrated differences in salivary amounts and molecular forms of MMPs and TIMP-1 in HIV+ patients. The results may reflect alterations in host defence reactions associated with HIV infection.

Matrix metalloproteinases, tissue inhibitor of matrix metalloproteinase-1, and laminin-5 gamma2 chain immunolocalization in gingival tissue of endotoxin-induced periodontitis in rats: effects of low-dose doxycycline and alendronate

BACKGROUND

Matrix metalloproteinases (MMPs) play important roles in tissue destruction mechanisms of periodontitis. MMP-8 and -13 are the major collagenases that act in extracellular matrix degradation in periodontal tissues. MMP-14 is a membrane-type MMP, and laminin (Ln)-5 is a basal membrane component. The aim of the present study was to evaluate the effects of doxycycline and alendronate on gingival tissue expression of MMP-8, -13, and -14; tissue inhibitors of MMP (TIMP)-1; and Ln-5 gamma2 chain in experimental periodontitis induced by Escherichia coli endotoxin (LPS) in rats.

METHODS

Experimental periodontitis was induced by repeated injection of LPS. Forty-four adult male Sprague-Dawley rats were divided into five study groups: saline control, LPS, LPS + doxycycline, LPS + alendronate, and LPS + doxycycline + alendronate. Doxycycline and alendronate were given as a single agent or as combination therapy during the 7 days of the experimental study period. On day 7, the rats were sacrificed, and the gingival tissues were analyzed immunohistochemically for expression of MMP-8, -13, and -14, Ln-5 gamma2 chain, and TIMP-1. Alveolar bone loss was evaluated morphometrically under a stereomicroscope. Data were tested statistically by Kruskal-Wallis and Mann-Whitney tests and Spearman correlation analysis.

RESULTS

Alveolar bone loss was significantly higher in the LPS, doxycycline, alendronate, and combination groups than in the saline control group (all P <0.01). MMP-8 expression was significantly higher in the LPS group than in the saline control group (P = 0.001). Individual administration of doxycycline or alendronate significantly decreased the expression of MMP-8 compared to LPS (P = 0.01). Combined drug administration reduced MMP-14 significantly compared to doxycycline (P = 0.004). No significant differences in Ln-5 gamma2 chain expression were found between the study groups (P >0.05). MMP-14 significantly correlated with the Ln-5 gamma2 chain in the LPS + alendronate group (P = 0.04) and with the amount of alveolar bone loss in the LPS + doxycycline + alendronate group (P = 0.03).

CONCLUSIONS

Our findings suggest that alendronate and/or doxycycline may inhibit MMP-8 expression significantly; particularly, their combined administration may provide beneficial effects in periodontal treatment. Moreover, individual administration of alendronate and doxycycline results in significant increases in TIMP-1 expression in gingiva. However, these effects of combined low-dose doxycycline and alendronate on MMPs and TIMP should be verified by clinical human trials before these agents are used in dental practice.

Metalloproteinases Control Brain Inflammation Induced by Pertussis Toxin in Mice Overexpressing the Chemokine CCL2 in the Central Nervous System

Inflammatory leukocytes infiltrate the CNS parenchyma in neuroinflammation. This involves cellular migration across various structures associated with the blood-brain barrier: the vascular endothelium, the glia limitans, and the perivascular space between them. Leukocytes accumulate spontaneously in the perivascular space in brains of transgenic (Tg) mice that overexpress CCL2 under control of a CNS-specific promoter. The Tg mice show no clinical symptoms, even though leukocytes have crossed the endothelial basement membrane. Pertussis toxin (PTx) given i.p. induced encephalopathy and weight loss in Tg mice. We used flow cytometry, ultra-small superparamagnetic iron oxide-enhanced magnetic resonance imaging, and immunofluorescent staining to show that encephalopathy involved leukocyte migration across the glia limitans into the brain parenchyma, identifying this as the critical step in inducing clinical symptoms. Metalloproteinase (MPs) enzymes are implicated in leukocyte infiltration in neuroinflammation. Unmanipulated Tg mice had elevated expression of tissue inhibitor of metalloproteinase-1, matrix metalloproteinase (MMP)-10, and -12 mRNA in the brain. PTx further induced expression of tissue inhibitor of metalloproteinase-1, metalloproteinase disintegrins-12, MMP-8, and -10 in brains of Tg mice. Levels of the microglial-associated MP MMP-15 were not affected in control or PTx-treated Tg mice. PTx also up-regulated expression of proinflammatory cytokines IL-1beta and TNF-alpha mRNA in Tg CNS. Weight loss and parenchymal infiltration, but not perivascular accumulation, were significantly inhibited by the broad-spectrum MP inhibitor BB-94/Batimastat. Our finding that MPs mediate PTx-induced parenchymal infiltration to the chemokine-overexpressing CNS has relevance for the pathogenesis of human diseases involving CNS inflammation, such as multiple sclerosis.

Gingival crevicular fluid matrix metalloproteinase-13 levels and molecular forms in various types of periodontal diseases

BACKGROUND

The purpose of this study was to evaluate the levels, molecular forms and activation degree of matrix metalloproteinase-13 (MMP-13) in the gingival crevicular fluid (GCF) of patients with periodontal diseases and to correlate these findings with periodontal clinical parameters.

METHODS

Sixty one subjects participated in this study as healthy (n = 18), gingivitis (n = 17), aggressive periodontitis (AgP; n = 15) and chronic periodontitis (CP; n = 11) groups. Clinical measurements and GCF samples were obtained from each subject. The molecular forms of MMP-13 in GCF samples were analyzed by Western immunoblotting method. Differences among the groups were assessed using non-parametric statistical analysis.

RESULTS

In the CP group, levels of 29-30 kDa fragment of MMP-13, total MMP-13, and activated form of MMP-13 were significantly higher than in the healthy, gingivitis and AgP groups. GCF levels of all molecular forms of MMP-13 in AgP group were similar to those of healthy and gingivitis groups. Total and activated MMP-13 levels were positively correlated with all clinical parameters. 29-30 kDa fragment levels of MMP-13 were also positively correlated with papillary bleeding index and plaque index.

CONCLUSION

These results indicate that elevated GCF MMP-13 levels may play an important role in the pathogenesis of CP. These data demonstrate, for the first time, pathologically activated and elevated MMP-13 in GCF.

IL-23 mediates inflammatory responses to mucoid Pseudomonas aeruginosa lung infection in mice

Patients with cystic fibrosis (CF) develop chronic Pseudomonas aeruginosa lung infection with mucoid strains of P. aeruginosa; these infections cause significant morbidity. The immunological response in these infections is characterized by an influx of neutrophils to the lung and subsequent lung damage over time; however, the underlying mediators to this response are not well understood. We recently reported that IL-23 and IL-17 were elevated in the sputum of patients with CF who were actively infected with P. aeruginosa; however, the importance of IL-23 and IL-17 in mediating this inflammation was unclear. To understand the role that IL-23 plays in initiating airway inflammation in response to P. aeruginosa, IL-23p19(-/-) (IL-23 deficient) and wild-type (WT) mice were challenged with agarose beads containing a clinical, mucoid isolate of P. aeruginosa. Levels of proinflammatory cytokines, chemokines, bacterial dissemination, and inflammatory infiltrates were measured. IL-23-deficient mice had significantly lower induction of IL-17, keratinocyte-derived chemokine (KC), and IL-6, decreased bronchoalveolar lavage (BAL) neutrophils, metalloproteinase-9 (MMP-9), and reduced airway inflammation than WT mice. Despite the reduced level of inflammation in IL-23p19(-/-) mice, there were no differences in the induction of TNF and interferon-gamma or in bacterial dissemination between the two groups. This study demonstrates that IL-23 plays a critical role in generating airway inflammation observed in mucoid P. aeruginosa infection and suggests that IL-23 could be a potential target for immunotherapy to treat airway inflammation in CF.