Regulation of the mammalian collagenases

Electronic cigarette liquid substances propylene glycol and vegetable glycerin induce an inflammatory response in gingival epithelial cells

Information on the effects of propylene glycol (PG) and vegetable glycerin (VG) and on cytotoxicity and subsequent activation of the biological mediators is limited in periodontal diseases. This study analyzes the effect of unflavored PG/VG alone or in combination with nicotine on gingival epithelial cells. The cells were exposed to different PG/VG (± nicotine) concentrations for 24 h and cytotoxicity was evaluated by calorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromid assay. The expressions of interleukin (IL)-6, IL-8, and matrix metalloproteinases (MMPs)-9 were measured using an enzyme-linked immunosorbent assay and a western blotting. Stimulation with PG/VG mixtures reduced cell viability compared to nonexposed controls (p < 0.05). Adding PG/VG increased the levels of IL-6, IL-8, and MMP-9, and the amount of PG had more biological impact compared to the VG amount. The nicotine augmented this effect compared to its nicotine-free counterparts. In western blotting result, MMP-9 was clearly activated in almost all samples. These findings suggest that the main constituents PG/VG are cytotoxic and able to induce biological response in gingival cells in vitro. Despite being advertised as less harmful than conventional cigarettes, electronic cigarette liquid pose certain risks on periodontal cells. Awareness about the effects of electronic cigarettes on periodontal diseases must be increased.

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.

Enzyme-mediated proteolysis of fibrous biopolymers: Dissolution front movement in fibrin or collagen under conditions of diffusive or convective transport

A numerical model based on the convective-diffusive transport of reacting and adsorbing proteolytic enzymes within erodible fibrous biopolymers was used to predict lysis fronts moving across biogels such as fibrin or collagen. The fiber structure and the transport properties of solutes in fibrin (or collagen) were related to the local extent of dissolution within the dissolving structure. An accounting for solubilization of adsorbed species into solution from the eroding fiber phase provided for complete conservation of mass in reacting systems containing over 10 species. At conditions of fibrinolysis typical of clinical situations, the model accurately predicted the dynamic rate of lysis front movement for plasmin, urokinase, and tissue plasminogen activator (tPA)-mediated lysis of fibrin gels measured in vitro. However, under conditions of extremely fast fibrinolysis using high enzyme concentrations, fibrinolytic fronts moved very rapidly (>0.1 mm/mm)-faster than predicted for diffusionlimited reactions-at nearly constant velocity for over 2 h, indicating non-Fickian behavior. This was due to proteolysis-mediated retraction of dissolving fibrin fibers that resulted in fiber convection and front-sharpening within 3 mum of the reaction front, as observed by digitally enhanced microscopy. In comparing the model to fibrinolysis measurements using human lys(77)-plasmin, the average first order rate constant for non-crosslinked fibrin bond cleavage by fibrin-bound plasmin was calculated to be 5s(-1) assuming that 10 cleavages per fibrin monomer were required to solubilize each monomer. The model accurately predicted lysis front movement using pressure-driven permeation of plasmin or urokinase into fibrin as well as literature data obtained under well- mixed conditions for tPA-mediated fibrinolysis. This numerical formulation provides predictive capability for optimization of proteolytic systems which include thrombolytic therapy, wound healing, controlled drug release, and tissue engineering applications. (c) 1995 John Wiley & Sons, Inc.

Is tissue engineering and biomaterials the future for lower urinary tract dysfunction (LUTD)/pelvic organ prolapse (POP)?

The fields of tissue engineering and regenerative medicine have seen major advances over the span of the past two decades, with biomaterials playing a central role. Although the term "regenerative medicine" has been applied to encompass most fields of medicine, in fact urology has been one of the most progressive. Many urological applications have been investigated over the past decades, with the culmination of these technologies in the introduction of the first laboratory-produced organ to be placed in a human body.1 With the quality of life issues associated with urinary incontinence, there is a strong driver to identify and introduce new technologies and the potential exists for further major advancements from regenerative medicine approaches using biomaterials, cells or a combination of both. A central question is why use biomaterials? The answer rests on the need to make up for inadequate or lack of autologous tissue, to decrease morbidity and to improve long-term efficacy. Thus, the ideal biomaterial needs to meet the following criteria: (1) Provide mechanical and structural support, (2) Maintain compliance and be biocompatible with surrounding tissues, and (3) Be "fit for purpose" by meeting specific application needs ranging from static support to bioactive cell signaling. In essence, this represents a wide range of biomaterials with a spectrum of potential applications, from use as a supportive or bulking implant alone, to implanted biomaterials that promote integration and eventual replacement by infiltrating host cells, or scaffolds pre-seeded with cells prior to implant. In this review we shall discuss the structural versus the integrative uses of biomaterials by referring to two key areas in urology of (1) pelvic organ support for prolapse and stress urinary incontinence, and (2) bladder replacement/augmentation.

Are protease inhibitors required for gel-based proteomics of kidney and urine?

Proteolysis is one of the major problems in collection and storage of biological samples for proteome analysis, particularly when the samples undergo freeze-thaw cycles. The use of protease inhibitors for prevention of such proteolysis in some samples is debated because protease inhibitors may interfere with proteome analysis and whether protease inhibitors are useful for renal and urinary proteomics remains unclear. We therefore performed a systematic evaluation of the use of protease inhibitors in gel-based renal and urinary proteomics. Renal proteins were extracted from porcine kidney tissue and stored at -30 or -70 degrees C without protease inhibitors. After 0, 2, 4, 6, 8, 10, and 12 freeze-thaw cycles, the 2-D proteome profile was examined. Differential spot analysis and ANOVA with Tukey posthoc multiple comparisons revealed significantly quantitative changes in intensity levels of 12 and 7 renal proteins that were stored at -30 and -70 degrees C, respectively, after >or=4 freeze-thaw cycles. Additionally, there were qualitative changes (vertical elongation or streak) in 6 and 1 renal proteins that were stored at -30 and -70 degrees C, respectively. All these changes could be successfully prevented by the addition of 1% (v/v) protease inhibitors cocktail prior to storage. In contrast, neither quantitative nor qualitative changes were observed in urine samples that were stored without protease inhibitors and processed as for kidney samples. From these data, the addition of protease inhibitors is highly recommended for gel-based renal proteomics, but no longer recommended for gel-based urinary proteomics.

Cytokines

During physiological and pathological skeletal remodelling, immune cells and stromal fibroblasts near active bone-forming and bone-resorbing surfaces might modulate the functions of skeletal tissue cells. Osteoblasts, osteoclasts and their progenitor cells are the probable direct targets of these effector cells (e.g. lymphocytes and monocytes) which act through direct contact or the release of soluble ligands (e.g. interleukin 1 or tumour necrosis factor, lymphotoxins, transforming growth factors). These cytokines bind to specific cellular receptors, resulting in changes in the form and function of the target bone cells and variable activation of genes coding for extracellular matrix proteins and proteinases which are responsible for remodelling the matrix. The synthesis and release of eicosanoids such as prostaglandins (e.g. PGE2) are frequent associated events. PGE2, in turn, affects several functions of the skeletal tissue cells as well as the lymphocytes and monocytes in their environment. The mesenchymal cells may also be induced to release ligands such as colony-stimulating factors, other cellular products or hormones resulting in a system of feedback and amplification loops. The cellular responses are thus subject to multiple controls not only determined by these ligands acting on their respective receptors but also by the pathways of signal transduction and how they, in turn, are influenced by interactions with molecules within the cells.

Excretion of collagen derived peptides is increased in women with stress urinary incontinence

AIMS

The objective of this study was to demonstrate that weakened pelvic floor support of the lower genitourinary tract in women with stress urinary incontinence (SUI) is due to increased collagenolysis. When fibrillar collagen is degraded, pyridinium (PYD) crosslinks are released and excreted in the urine. Degradation of collagen also results in peptide fragments of various lengths which are excreted in the urine. Degradation of mature fibrillar collagen and collagen which has not been crosslinked can be assessed independently by measurement of both PYD and collagen-derived peptides in the urine.

METHODS

Twenty-four hour urine collections were obtained from women with SUI (n = 23) and women without urinary incontinence (n = 39). Urinary PYD concentration was assayed by ELISA. The urinary concentration of helical peptide alpha1 (I) 620-633 fragments derived from collagen was assayed by competitive enzyme immunoassay. Values were normalized to creatinine.

RESULTS

The mean urine PYD concentration for women with SUI (110.8 +/- 19.7 nM/mM creatinine) was not significantly different than that for women without SUI (85.2 +/- 13.7 nM/mM creatinine). The mean urine concentration of helical peptide alpha1 (I) 620-633 for women with SUI (0.80 +/- 0.13 microg/mg creatinine) was significantly (P < 0.02) higher than that for women without SUI (0.49 +/- 0.06 microg/mg creatinine).

CONCLUSIONS

These data suggest that collagenolytic activity in women with SUI is elevated compared to continent controls, as measured by urinary helical peptide alpha1 (I) 620-633 excretion. The lack of difference in urinary PYD excretion between the two populations suggests that the increased collagenolytic activity in women with SUI, compared to continent controls, is restricted to uncrosslinked collagen.

Relaxin increases secretion of matrix metalloproteinase-2 and matrix metalloproteinase-9 during uterine and cervical growth and remodeling in the pig

Matrix metalloproteinases are proteolytic enzymes that degrade the extracellular matrix and are essential for tissue remodeling. Uterine and cervical growth require remodeling of structural barriers to cell invasion and matrix metalloproteinase-2 and -9 degrade type IV collagen, the major component of basement membranes. Relaxin stimulates uterine and cervical growth and remodeling, which includes remodeling of support elements such as basement membranes. The objective of this study was to determine whether relaxin alters the production and/or activity of matrix metalloproteinase-2 and -9 in the uterus or cervix of the pig. The growth-promoting effects of relaxin were elicited by administering relaxin to prepubertal gilts every 6 h for 54 h. The expression of matrix metalloproteinase-2 and matrix metalloproteinase-9 was characterized by gel zymography, and proteins were quantified by immunoblotting. Total enzyme activity was measured using matrix metalloproteinase-specific fluorescent substrate assays. In both uterine and cervical tissues, immunoreactive matrix metalloproteinase-2 and matrix metalloproteinase-9 protein expression was similar in relaxin-treated and control animals. However, tissue-associated gelatinase activity was attenuated by relaxin (P < 0.05). In contrast, relaxin significantly increased the secretion of active matrix metalloproteinase-2 and -9 protein into uterine fluid (P < 0.05). Given the importance of matrix metalloproteinases in extracellular matrix degradation, the observation that relaxin promotes uterine secretion of matrix metalloproteinase-2 and -9 supports the concept that relaxin facilitates the growth and remodeling of reproductive tissues by increasing extracellular proteolysis in the pig reproductive tract.

Effects of dehydroepiandrosterone on collagen and collagenase gene expression by skin fibroblasts in culture

Dehydroepiandrosterone (DHEA) and its sulfate (DHEA-S) are the most abundant steroids in humans whose low levels are related to aging, greater incidence of various cancers, immune dysfunction, atherosclerosis, and osteoporosis. It has been shown that collagen and collagenase gene expression decreases in fibroblasts taken from more aged donors. In this paper, to investigate the relationship between DHEA and skin aging, we examined the effects of DHEA on the regulation of collagen, collegians and stromelysin-1 genes in cultured human skin fibroblasts. In collagen assay, DHEA slightly increased collagen production in a dose-related fashion, its maximal effect occurred at 10(-5) M DHEA (P>0.05). In the presence of DHEA, steady-state levels of alpha1 (I) procollagen mRNA increased to 1. 6-fold of the non-treated group, while those of fibronectin were not. Interestingly, DHEA differently regulated collagenase and stromelysin-1 gene expression. The steady-state levels of collagenase mRNA decreased in response to DHEA by 40%, whereas those of stromelysin-1 mRNA increased up to 2.4-fold, compared to controls. Similar results were obtained for chloramphenicol acetyltransferase assay (CAT); maximal promoter activation of stromelysin-1 gene occurred at 10(-6) M DHEA, 4.5-fold higher than control. CAT assay revealed that treatment with 10(-5) M DHEA resulted in a strong ( approximately 70%) inhibition of the collagenase promoter activity. In our experiments, the effects of DHEA on these gene expressions were higher at pharmacologic concentration (>/=10(-5) M) than those at physiologic concentration (10(-8)-10(-6) M). This study suggests that the level of DHEA may be related to the process of skin aging through the regulation of production and degradation in extracellular matrix.

Differential regulation of type IV collagenases and metalloelastase in murine macrophages by the synthetic bacterial lipopeptide JBT 3002

We determined whether the expression of matrix metalloproteinases (MMP) and tissue inhibitors of MMPs (TIMP) in murine macrophages is regulated by the novel synthetic bacterial lipopeptide JBT 3002. Multilamellar liposomes (MLV) encapsulating JBT 3002 (MLV-JBT 3002) stimulated the production of 72-kDa and 92-kDa (gelatinase A and B) type IV collagenase and inhibited the production of murine metalloelastase (MME) in a dose-dependent manner in murine peritoneal macrophages. MLV-JBT 3002 also induced production of TIMP-1. MLV-JBT 3002 did not induce collagenase production in tumor cells. Priming murine macrophages with interferon-gamma (IFN-gamma) inhibited JBT 3002-stimulated production of both MMP-9 and MMP-2 and further inhibited production of MME by a mechanism involving nitric oxide (NO). This conclusion is based on data showing that IFN-gamma failed to inhibit production of MMP in the presence of L-methyl arginine or in macrophages from inducible nitric oxide synthase knockout mice. These data suggest that JBT 3002 differentially regulates the production of various MMPs and TIMP in macrophages.

Treatment with anti-transforming growth factor beta antibodies influences an altered pattern of cytokines gene expression in injured rat liver

The role of transforming growth factor beta1 (TGF-beta1) in mediating hepatic inflammation and regeneration after acute liver injury is beginning to be elucidated, yet its in vivo effect on the gene expression of the major pro-inflammatory and anti-inflammatory cytokines produced during that process is unknown. Our previous experiments demonstrated that anti-TGF-beta-treated animals presented profound histological changes as compared with control animals. Therefore, our hypothesis was that by blocking in vivo TGF-beta1 action, with polyclonal anti-TGF-beta antibodies, we could monitor by RT-PCR significative alterations on the gene expression of IL-1beta, IL-6, TGF-beta, TNF-alpha, IL-4 and IL-10 in liver-regenerated rats after administration of a single CCl4 dosing. Accordingly, we here report a completely different pattern of cytokines gene expression amidst those groups of rats. Pro-inflammatory cytokines gene expression in control animals showed a clear-cut pattern peaking at 1-2 days postinjury and declining thereafter. Interestingly, IL-6 was present in the control animals only between 12 and 24 h after CCl4 dosing. In the experimental animals, TGF-beta1 was mainly increased at 4 and 6 days, while IL-6 mRNA was completely absent. IL-1beta mRNA expression was also altered in the experimental rats, albeit TNF-alpha was nearly unaffected. IL-4 was fully absent in control rats, but remarkably expressed in experimental animals throughout the study. IL-10 was also more expressed in experimental animals.

Matrix metalloproteinases: the clue to intervertebral disc degeneration?

STUDY DESIGN

A review of the current literature on the role of matrix metalloproteinases in intervertebral disc degeneration.

OBJECTIVE

To detail the characteristics of matrix metalloproteinases (classification, structure, substrate specificity and regulation) and to report previous studies of intervertebral discs.

SUMMARY OF BACKGROUND DATA

Degeneration of the intervertebral disc, a probable prerequisite to disc herniation, is a complex phenomenon, and its physiopathologic course remains unclear. Matrix metalloproteinases probably play an important role but have received sparse attention in the literature.

METHODS

A systematic review of studies reporting a role of matrix metalloproteinases in intervertebral disc degeneration.

RESULTS

In several studies, investigators have reported the presence of proteolytic enzymes from disc culture systems and disc tissue extracts in degenerated human intervertebral discs, especially collagenase-1 (MMP-1) and stromelysin-1 (MMP-3). The matrix metalloproteinases are regulated by specific inhibitors (tissue inhibitors of metalloproteinases, or TIMPS), cytokines (interleukin-1), and growth factors.

CONCLUSIONS

This field of application is of particular interest because conventional treatments are disappointing in chronic low back pain. Clinical trials with specific inhibitors of metalloproteinases are beginning in osteoarthritis.

Matrix metalloproteinase gene expression in chronic gastric ulcer: a potential role of eosinophils in perforation

Gene expression of matrix degrading enzymes was investigated in surgical specimens of perforated gastric ulcers. In these ulcers, the inflammatory cells infiltrating into the granulation tissue were granulocytes, particularly eosinophils. The extracellular matrix of the stomach wall consists mainly of collagen types I and III, which are selectively degraded by matrix metalloproteinase-1 (MMP-1). MMP-1 mRNA was detected in the cytoplasm of infiltrating cells, suggesting that eosinophils play an important role in ulcer recurrence and in perforation of the stomach wall. The degree of eosinophil infiltration into an ulcer base may be a useful marker for the risk of perforation. Patients showing this marker may benefit from a prophylactic therapy for preventing severe complications. The control of MMP gene expression represents a potential strategy for the treatment of recurrent gastric ulcer.

Chemical injuries of the eye: current concepts in pathophysiology and therapy

Chemical injuries of the eye may produce extensive damage to the ocular surface epithelium, cornea, and anterior segment, resulting in permanent unilateral or bilateral visual impairment. Pathophysiological events which may influence the final visual prognosis and which are amenable to therapeutic modulation include 1) ocular surface injury, repair, and differentiation, 2) corneal stromal matrix injury, repair and/or ulceration, and 3) corneal and stromal inflammation. Immediately following chemical injury, it is important to estimate and clinically grade the severity of limbal stem cell injury (by assessing the degree of limbal, conjunctival, and scleral ischemia and necrosis) and intraocular penetration of the noxious agent (by assessing clarity of the corneal stroma and anterior segment abnormalities). Immediate therapy is directed toward prompt irrigation and removal of any remaining reservoir of chemical contact with the eye. Initial medical therapy is directed promoting re-epithelialization and transdifferentiation of the ocular surface, augmenting corneal repair by supporting keratocyte collagen production and minimizing ulceration related to collagenase activity, and controlling inflammation. Early surgical therapy if indicated, is directed toward removal of necrotic corneal epithelium and conjunctiva, prompt re-establishment of an adequate limbal vascularity, and re-establishment of limbal stem cell population early in the clinical course, if sufficient evidence exists of complete limbal stem cell loss. Re-establishment of limbal stem cells by limbal autograft or allograft transplantation, or by transfer in conjunction with large diameter penetrating keratoplasty, may facilitate development of an intact, phenotypically correct corneal epithelium. Limbal stem cell transplantation may prevent the development of fibrovascular pannus or sterile corneal corneal ulceration, simplify visual rehabilitation, and improve the visual prognosis. Advances in ocular surface transplantation techniques which allow late attempts at visual rehabilitation of a scarred and vascularized cornea include limbal stem cell transplantation for incomplete transdifferentiation and persistent corneal epithelial dysfunction, and conjunctival and/or mucosal membrane transplantation for ocular surface mechanical dysfunction. Rehabilitation of the ocular surface may be followed, if necessary, by standard penetrating keratoplasty if all aspects of ocular surface rehabilitation are complete, or by large diameter penetrating keratoplasty if successful limbal stem cell transplantation cannot be achieved but other ocular surface rehabilitation is complete.

Expression of matrix metalloproteinase 9 (96-kd gelatinase B) in human rheumatoid arthritis

OBJECTIVE

To determine the expression of matrix metalloproteinase 9/gelatinase B (MMP-9) in synovial fluid (SF), plasma, and synovial tissue from individuals with rheumatoid arthritis (RA), inflammatory arthritis (IA), and osteoarthritis (OA), using specific monoclonal antibody reagents.

METHODS

Gelatinolytic activity in the SF and plasma of patients with RA, IA, and OA was assessed by gelatin zymography. A mouse monoclonal antiserum, 277.13, which selectively recognizes soluble latent forms of human MMP-9, was used to quantitate MMP-9 levels in patient synovial effusions, plasma, and synovial tissue with a capture sandwich enzyme-linked immunosorbent assay (ELISA). Fifty-one SF samples (31 RA, 9 OA, 11 IA) were analyzed. Immunolocalization of MMP-9 in RA, OA, and normal synovium was investigated using MMP-9-specific antisera.

RESULTS

MMP-9 antigen levels in synovial effusions were elevated 67-fold in RA samples compared with OA samples. In addition, although MMP-9 antigen levels in IA synovial effusions were 2.7-fold less than the values in RA samples, they were elevated 34-fold over the values in OA samples. These data indicate an association between increased MMP-9 levels and inflammatory arthritis. A predominant 92-kd gelatinolytic activity (specifically inhibited by EDTA) was evident in RA and IA samples, but no activity was observed in OA samples. Among 86 plasma samples (17 RA, 9 IA, 60 normal controls) analyzed for MMP-9 antigen levels by immunocapture ELISA, MMP-9 antigen levels were elevated 7-fold in RA plasma compared with normal plasma. RA synovial tissue extracts demonstrated elevated levels of MMP-9 antigen compared with OA synovial tissue. MMP-9 immunolocalization studies demonstrated expression in infiltrating leukocytes (neutrophils and macrophages), endothelial cells, and synovial fibroblasts in RA synovium.

CONCLUSION

Latent MMP-9 and/or MMP-9-tissue inhibitor of metalloproteinases 1 (TIMP-1) complexes are elevated in RA and IA SF compared with OA SF. In addition, MMP-9 is increased in RA plasma versus normal control plasma. Synovial tissue levels of MMP-9 antigen are also elevated in RA versus OA. The tissue distribution of MMP-9 within RA synovium is localized to sites of inflammation comprising surface synovial lining cells, endothelium, and leukocytes. Taken together, these observations suggest that connective tissue turnover occurs as a result of excessive MMP activity over TIMP action in the invading pannus, periarticular tissue, or SF. Further studies such as those used in the present investigation will help elucidate the role of a number of different enzymes and inhibitors in the destructive arthropathies.

Periodontal ligament cells are chemotactic to fibroblast collagenase

Periodontal ligament (PDL) cell motility and the passage of PDL cells along a root surface are important components of tissue remodeling during periodontal regeneration. Proteolytic enzymes, including fibroblast collagenase, have been demonstrated to play an important role in tissue remodeling. Previous studies have shown that PDL cells chemotactically respond to a variety of matrix and growth factors. We therefore studied the effects of type I collagen fragments and fibroblast collagenase on PDL cell migration, since PDL cells have been shown to adhere preferentially to partially demineralized root surfaces with exposed type I collagen. Gingival epithelial cells were used as a control cell population. We report that PDL cells but not gingival epithelial cells preferentially migrate in a dose-dependent manner to both fibroblast collagenase and to type I collagen degradation products. Epithelial cell migration to fibroblast collagenase and type I collagen fragments was observed. Antibody to type I collagen inhibited the type I collagen fragment-mediated migration. Collagenase pre-treatment of PDL cells enhanced PDL cell migration to type I collagen fragments. In other assays, enzyme inhibitors were shown to decrease the collagenase-mediated PDL cell motility. Epithelial cells were shown to migrate preferentially to 92-kDa type IV collagenase and type IV collagen degradation products. Antibody to type IV collagen inhibited type IV collagen-induced epithelial cell migration. Taken together, these data suggest a role for collagenase in the fine control of PDL cell migration in tissue remodeling during periodontal regeneration.

In situ hybridization of stromelysin mRNA in the synovial biopsies from rheumatoid arthritis

We examined the expression of stromelysin mRNA (SL mRNA) in synovial biopsy specimens from 12 cases of rheumatoid arthritis (RA) and 2 cases of osteoarthritis (OA) using in situ hybridization. The study demonstrated that positive cells with high levels of SL mRNA were mostly (85%) found in the synovial lining layer. The positive cells were abundant in the synovium of RA which presented well developed lymphoid follicles with massive inflammatory cells. On the other hand, the synovium of OA contained no positive cells for SL mRNA. In addition, low yet positive levels of SL mRNA were detected in the endothelial cells and vascular myocytes, and interstitial cells in the deeper layer of the synovium. Karyometric studies showed that cells positive for SL mRNA had significantly larger and more spherical nuclei than weakly positive or negative cells. The SL mRNA positive cells did not demonstrate any immunoreactivity to markers of bone marrow origin, such as Leu M1, Leukocyte Common Antigen (LCA) and lysozyme antigen. Electron microscopy of a case with many SL mRNA positive cells showed that most had well developed rough endoplasmic reticulum and numerous processes on the cell surface, and some had also well developed rough endoplasmic reticulum but without processes indicating that they may be AB and/or B synoviocytes.

Expression of MMP-1 in the capsule of thyroid cancer--relationship with invasiveness

To investigate the invasive activity of thyroid cancer, an in situ hybridization study was carried out in 19 thyroid tumors, including nine papillary carcinomas, five follicular carcinomas and five follicular adenomas, by using a 35S-labeled MMP-1 (matrix metalloproteinase-1) cDNA probe. The MMP-1 gene was expressed not in the cancer cells but in the fibrous capsules of papillary carcinoma. Thyroid cancer is generally circumscribed by a fibrous capsule. We found that types I and III collagen constitute the fibrous capsule, and that the MMP-1 gene was expressed in the outer border of these sites. These findings suggest that MMP-1 plays an important role in the invasion of thyroid cancer.

Doxycycline inhibits neutrophil (PMN)-type matrix metalloproteinases in human adult periodontitis gingiva

We previously reported that low-dose doxycycline (DOXY) therapy reduces host-derived collagenase activity in gingival tissue of adult periodontitis (AP) patients. However, it was not clear whether this in vivo effect was direct or indirect. In the present study, inflamed human gingival tissue, obtained from AP patients during periodontal surgery, was extracted and the extracts partially purified by (NH4)2SO4 precipitation. The extracts were then analyzed for collagenase activity using SDS-PAGE/fluorography/laser densitometry, and for gelatinase activity using type I gelatin zymography as well as a new quantitative assay using biotinylated type I gelatin as substrate. DOXY was added to the incubation mixture at a final concentration of 0-1000 microM. The concentration of DOXY required to inhibit 50% of the gingival tissue collagenase (IC50) was found to be 16-18 microM in the presence or absence of 1.2 mM APMA (an optimal organomercurial activator of latent procollagenases); this IC50 for DOXY was similar to that exhibited for collagenase or matrix metalloproteinase (MMP)-8 from polymorphonuclear leukocytes (PMNs) and from gingival crevicular fluid (GCF) of AP patients. Of interest, Porphyromonas gingivalis collagenase was also inhibited by similar DOXY levels (IC50 = 15 microM), however the collagenase activity observed in the gingival tissue extracts was found to be of mammalian not bacterial origin based on the production of the specific alpha A (3/4) and alpha B (1/4) collagen degradation fragments. In contrast, the inhibition of collagenase purified from culture media of human gingival fibroblasts (MMP-1) required much greater DOXY levels (IC50 = 280 microM). The predominant molecular forms of gelatinolytic activity presented in the AP patients gingival tissue extracts were found to closely correspond to the 92 kD PMN-type gelatinase (MMP-9) although small quantities of 72 kD fibroblast-type gelatinase (MMP-2), and some other low molecular weight gelatinases, were also detected. The IC50 of DOXY versus gingival tissue gelatinolytic activity was estimated at 30-50 microM measure using either type I gelatin zymography or the biotinylated type I gelatin assay. We conclude that MMPS in inflamed gingival tissue of AP patients, like those in GCF, originate primarily from infiltrating PMNs rather than resident gingival cells (fibroblasts and epithelial cells) or monocyte/macrophages, and that their pathologically-elevated tissue-degrading activities can be directly inhibited by pharmacologic levels of doxycycline.

Synthesis and secretion of matrix-degrading metalloproteases by human skeletal muscle satellite cells

The expression of matrix-degrading metalloproteases (MMPs) by human skeletal muscle satellite cells was investigated by zymography of cell culture media and by Northern blot analysis of mRNA prepared from satellite cells. Zymography in gelatin substrate gels revealed that satellite cells constitutively synthesize and secrete 72 kDa gelatinase (MMP-2). In addition, treatment of satellite cell cultures with phorbol ester resulted in an induction of 92 kDa gelatinase (MMP-9) activity. On casein substrate gels, little or no proteolytic activity was detectable in control or phorbol ester treated satellite cell cultures, suggesting that compared to fibroblasts, satellite cells secrete little or no interstitial collagenase (MMP-1) or stromelysin (MMP-3) activity. Northern blotting, however, revealed that there is detectable expression of mRNA transcripts encoding MMP-1 in satellite cell cultures, and that increased accumulation of MMP-1 mRNA transcripts occurs upon treatment of these cells with phorbol ester. In contrast, no constitutive, or induced expression of transcripts encoding MMP-3 was detectable in satellite cells. These findings show that satellite cells can synthesize and secrete selected members of the MMP family and suggest that skeletal muscle cells may participate directly in remodelling of the extracellular matrix during myogenesis and the regeneration of skeletal muscle.

Regulation of collagenase gene expression by IL-1 beta requires transcriptional and post-transcriptional mechanisms

Interleukin-1 beta is believed to contribute to the pathophysiology of rheumatoid arthritis by activating collagenase gene expression. We have used a cell culture model of rabbit synovial fibroblasts to examine the molecular mechanisms of IL-1 beta-mediated collagenase gene expression. Stimulation of rabbit synovial fibroblasts with 10 ng/ml recombinant human IL-1 beta resulted in a 20-fold increase in collagenase mRNA by 12 h. Transient transfection studies using collagenase promoter-CAT constructs demonstrated that proximal sequences responded poorly to IL-1 beta, possibly due to insufficient activation of AP-1 by this cytokine. More distal sequences were required for IL-1 beta responsiveness, with a 4700 bp construct showing approximately 5-fold induction above control. To examine post-transcriptional mechanisms, transcript from a human collagenase cDNA was constitutively produced by the simian virus 40 early promoter. IL-1 beta stabilized the constitutively expressed human transcript. Furthermore, mutation of the ATTTA motifs in the 3' untranslated region of the human gene also stabilized the transcript. Finally, the rabbit collagenase 3' untranslated region destabilized a constitutively transcribed chloramphenicol acetyltransferase transcript. These data indicate that in addition to activating transcription, IL-1 beta increases collagenase transcript stability by reversing the destabilizing effects of sequences in the 3' untranslated region.

Expression of metalloproteinases in pigmented villonodular synovitis

Pigmented villonodular synovitis (PVNS) is an idiopathic proliferative synovial process composed of two predominant cell types: mononuclear histiocytic cells and giant cells. This lesion can be locally invasive and can result in bone cyst formation and late cartilage and bone loss. Because metalloproteinases have been implicated in the joint destruction occurring in inflammatory arthritis and in the ability of certain tumors to invade adjacent tissues, their presence in PVNS was determined. Synovial tissue samples were collected at surgical synovectomy from the knees of 10 patients with a prior histological diagnosis of PVNS. Pigmented villonodular synovitis synovium was examined for the presence of the metalloproteinases collagenase and stromelysin. Messenger RNA (mRNA) for collagenase and stromelysin was present in all patient samples, although in varying amounts. In situ hybridization studies on synovial tissue sections identified synovial lining cells as the predominant cells expressing these metalloproteinases. Occasional infiltrating mononuclear histiocytic cells also were producing metalloproteinase mRNA. Giant cells did not express mRNA for the metalloproteinases collagenase and stromelysin. These results suggest that collagenase and stromelysin may be among the mediators of cartilage and bone loss that can occur in PVNS.

An investigation of the proteoglycan metabolism of mature equine articular cartilage and its regulation by interleukin-1

The effect of human recombinant interleukin-1 beta (rhIL-1 beta) on proteoglycan metabolism was investigated in cultures of full thickness explants of articular cartilage from horses 3-21 years of age. Proteoglycan synthesis was inhibited at all ages but no alteration in the hydrodynamic size or electrophoretic heterogeneity was observed in proteoglycan isolated from rhIL-1 beta stimulated cartilage. The sulphation pattern of the newly synthesised proteoglycan molecules was, however, significantly affected by the presence of the peptide regulatory factor. Interleukin-1 had no effect on the rate of turnover of newly synthesised or endogenous proteoglycans in mature equine articular cartilage and did not influence the structure of proteoglycan fragments released into the culture medium. These observations suggest that IL-1, released into synovial fluid during inflammation, may modify the proteoglycan composition of normal equine cartilage not by stimulating catabolic enzymes capable of degrading the resident proteoglycans but by promoting the deposition of a reduced number of newly synthesised proteoglycan molecules of abnormal composition.

Cytokine regulation of metalloproteinase gene expression

Matrix metalloproteinases belong to a family of zinc-dependent enzymes capable of degrading extracellular matrix and basement membrane components. Their expression is greatly modulated by cytokines and growth factors and involves the gene products of the Fos and Jun families of oncogenes. After extra(peri)cellular activation, their activity can be further controlled by specific tissue inhibitors of metalloproteinases. A correct balance between these regulatory mechanisms is necessary to ensure matrix remodeling in normal physiological processes such as embryonic development, but the overexpression of these enzymes may initiate or contribute to pathological situations such as cartilage degradation in rheumatoid arthritis or to tumor progression and metastasis. Delineation of the mechanisms of metalloproteinase and metalloproteinase inhibitors gene expression, understanding of their mode of interactions, and characterization of their patterns of expression in various tissues in normal and pathological states will lead to new therapeutic strategies to counteract the deleterious effects of matrix metalloproteinases in human disease.

Blocking periodontal disease progression by inhibiting tissue-destructive enzymes: a potential therapeutic role for tetracyclines and their chemically-modified analogs

Tetracyclines (TCs) have wide therapeutic usage as antimicrobial agents; these drugs (e.g., minocycline, doxycycline) remain useful as adjuncts in periodontal therapy. However, TCs also have non-antimicrobial properties which appear to modulate host response. In that regard, TCs and their chemically-modified analogs (CMTs) have been shown to inhibit the activity of the matrix metalloproteinase (MMP), collagenase. The activity of this enzyme appears crucial in the destruction of the major structural protein of connective tissues, collagen. Such pathologic collagenolysis may be a common denominator in tissue destructive diseases such as rheumatoid and osteoarthritis, diabetes mellitus, bullous dermatologic diseases, corneal ulcers, and periodontitis. The mechanisms by which TCs affect and, possibly, diminish bone resorption (a key event in the pathogenesis of periodontal and other diseases) are not yet understood. However, a number of possibilities remain open for investigation including the following: TCs may 1) directly inhibit the activity of extracellular collagenase and other MMPs such as gelatinase; 2) prevent the activation of its proenzyme by scavenging reactive oxygen species generated by other cell types (e.g. PMNs, osteoclasts); 3) inhibit the secretion of other collagenolytic enzymes (i.e. lysosomal cathepsins); and 4) directly affect other aspects of osteoclast structure and function. Several recent studies have also addressed the therapeutic potential of TCs and CMTs in periodontal disease. These drugs reduced excessive gingival collagenase activity and severity of periodontal breakdown in rats infected with Porphyromonas gingivalis and in diabetic rats. Furthermore, the latter drug (CMT) was not associated with the emergence of TC-resistant microorganisms.(ABSTRACT TRUNCATED AT 250 WORDS)

Susceptibility of type I collagen containing mutated alpha 1(1) chains to cleavage by human neutrophil collagenase

Two members of the matrix metalloproteinase family which can cleave native types I, II and III triple helical collagens are collagenases from fibroblasts and neutrophils. These enzymes are the products of different genes which share structural motifs but are only 57% identical. In this study, we determined the site of cleavage in the alpha 1(I) chains and showed that the neutrophil collagenase acted at the same site as the fibroblast collagenase. We also used collagens as substrates which were generated by site-directed mutagenesis of the murine Col1a1 gene and found that the pattern of susceptibility to cleavage by purified neutrophil collagenase was indistinguishable from that previously described for the fibroblast collagenase. Collagens containing substitutions of Pro for Ile-776 (P1) were not cleaved; whereas those containing substitutions of Met for Ile-776 were cleaved. Type I collagen which contained alpha 1(I) chains in which there were double substitutions of Pro for Gln-774 (P2) and Ala-777 (P2') were also not cleaved. These type I collagens contained wild type alpha 2(I) chains as well as mutant alpha 1(I) chains in the mixed helical trimers; the alpha 2(I) chain in the trimers containing the resistant alpha 1(I) chains were also not cleaved by the neutrophil collagenase.

Identification of tissue inhibitor of metalloproteinase-2 (TIMP-2)-progelatinase complex as the third metalloproteinase inhibitor peak in rheumatoid synovial fluid

The metalloproteinases are a family of enzymes that can degrade all the components of the extracellular matrix. These potent enzymes are often found in proenzyme forms and require activation before the substrate can be digested. To prevent unlimited connective tissue destruction a number of inhibitors exist to limit their activity. In a previous study it was found that metalloproteinases in proenzyme form and metalloproteinase inhibitors were often present in rheumatoid synovial fluids. Two of these inhibitors were identified in rheumatoid synovial fluid as alpha 2 macroglobulin and tissue inhibitor of metalloproteinase (TIMP), the specific metalloproteinase inhibitor. A third inhibitory peak was unidentified. In the study reported here it was shown that this third inhibitor can be purified using gelatin-Sepharose chromatography and consists of TIMP-2 bound to progelatinase (relative molecular weight 72,000) in a similar way to that found in concentrated connective tissue culture medium. The importance of these proteinase inhibitors in synovial fluid is discussed.

Direct evidence for active metalloproteinases mediating matrix degradation in interleukin 1-stimulated human articular cartilage

When adult human articular cartilage was maintained in organ culture in the presence of interleukin 1 beta, increased destruction of the extracellular matrix was observed, as judged by increased type II collagen degradation in situ determined immunohistochemically and the increased release of proteoglycan into the culture medium. Concomitant with these changes was the increased release of latent metalloproteinases into the culture medium. Culture of cartilage in the presence of a peptidylhydroxamate metalloproteinase inhibitor indicated a key role for the active forms of these enzymes in situ, since it produced a marked reduction in both proteoglycan release and collagen degradation. This compound had no detectable cytotoxic effects in organ culture and did not reduce the secretion of the metalloproteinases. The results of this study provide direct evidence that the latent metalloproteinase precursors, whose release is greatly stimulated by interleukin 1, are indeed activated to some degree and participate in cartilage matrix degradation.

beta-cyclodextrin tetradecasulfate/tetrahydrocortisol +/- minocycline as modulators of cancer therapies in vitro and in vivo against primary and metastatic Lewis lung carcinoma

Tetrahydrocortisol, beta-cyclodextrin tetradecasulfate, and minocycline used alone or in combination are not very cytotoxic toward EMT-6 mouse mammary tumor cells growing in monolayer. Tetrahydrocortisol (100 microM, 24 h) and beta-cyclodextrin tetradecasulfate (100 microM, 24 h) protected EMT-6 cells from the cytotoxicity of CDDP, melphalan, 4-hydroperoxycyclophosphamide, BCNU, and X-rays under various conditions of oxygenation and pH. Minocycline (100 microM, 24 h) either had no effect upon or was additive with the antitumor alkylating agents or X-rays in cytotoxic activity toward the EMT-6 cells in culture. The combination of the three modulators either had no effect upon or was to a small degree protective against the cytotoxicity of the antitumor alkylating agents or X-rays. The Lewis lung carcinoma was chosen for primary tumor growth-delay studies and tumor lung-metastases studied. Tetrahydrocortisol and beta-cyclodextrin tetradecasulfate were given in a 1:1 molar ratio by continuous infusion over 14 days, and minocycline was given i.p. over 14 days, from day 4 to day 18 post tumor implantation. The combination of tetrahydrocortisol/beta-cyclodextrin tetradecasulfate diminished the tumor growth delay induced by CDDP and melphalan and produced modest increases in the tumor growth delay produced by cyclophosphamide and radiation. Minocycline co-treatment increased the tumor growth delay produced by CDDP, melphalan, radiation, bleomycin, and, especially cyclophosphamide, where 4 of 12 animals receiving minocycline (14 x 5 mg/kg, days 4-18) and cyclophosphamide (3 x 150 mg/kg, days 7, 9, 11) were long-term survivors. The 3 modulators given in combination produced further increases in tumor growth delay with all of the cytotoxic therapies, and 5 of 12 of the animals treated with the 3-modulator combination and cyclophosphamide were long-term survivors. Although neither tetrahydrocortisol/beta-cyclodextrin tetradecasulfate, minocycline, nor the three modulator combination impacted the number of lung metastases, there was a decrease in the number of large lung metastases. Treatment with the cytotoxic therapies alone reduced the number of lung metastases. Addition of the modulators to treatment with the cytotoxic therapies resulted in a further reduction in the number of lung metastases. These results indicate that agents that inhibit the breakdown of the extracellular matrix can be useful additions to the treatment of solid tumors.

New perspectives on basic mechanisms in lung disease. 1. Lung injury, inflammatory mediators, and fibroblast activation in fibrosing alveolitis

It is over 25 years since Scadding first defined the term fibrosing alveolitis. It has since been established that complex mechanisms underlie its pathogenesis, including epithelial and endothelial injury, vascular leakage, production of inflammatory cells and their mediators, and fibroblast activation. Only through a detailed knowledge of how these cellular and molecular events are interlinked will we learn how to combat this disease, which is notoriously resistant to present treatments. So far the only therapeutic advances have been refinements in immunosuppression, and even these treatments are frequently disappointing. We believe that future advances in treatment will come from the development of agents that protect endothelial and epithelial cells from further injury and agents that can inhibit release of inflammatory mediators. A better knowledge of the mechanisms of collagen gene activation and the biochemical pathways of collagen production may also allow the identification of vulnerable sites at which new treatments may be directed. A combined approach to modifying appropriate parts of both the inflammatory component and the fibroblast/collagen component should provide a new stimulus to research. Further epidemiological studies are also needed to identify the environmental causes of lung injury that initiate the cascade of events leading to interstitial fibrosis.

Proteolytic activation of corneal matrix metalloproteinase by Pseudomonas aeruginosa elastase

Purified Pseudomonas aeruginosa elastase cleaved a 65 kDa gelatinase [inactive proenzyme form of matrix metalloproteinase (MMP-2)] from human corneal fibroblasts into a biologically active fragment with an approximate molecular mass of 58 kDa. However, purified pseudomonal alkaline protease did not cleave MMP-2 appreciably. Since activated MMP-2 is known to degrade native type IV, V and VII collagens, all components of the corneal basement membrane or stroma, our results suggest a new role for pseudomonal elastase in the pathogenesis of corneal infection, inflammation and ulceration.

Large inhibitor of metalloproteinases (LIMP) contains tissue inhibitor of metalloproteinases (TIMP)-2 bound to 72,000-M(r) progelatinase

Connective-tissue cells in culture produce a family of metalloproteinases which, once activated, can degrade all the components of the extracellular matrix. These potent enzymes are all inhibited by the tissue inhibitor of metalloproteinases (TIMP), and it was thought that this inhibitor was solely responsible for the inhibition of these enzymes within connective tissue. However, other inhibitors have recently been described, including large inhibitor of metalloproteinases (LIMP) present in the culture medium of human foetal lung fibroblasts. Here we show that a large proportion of the inhibitory activity of LIMP consists of 72,000-M(r)-progelatinase bound to TIMP-2, a recently discovered low-M(r) metalloproteinase inhibitor closely related to TIMP. The physiological implications of the secretion of a complex of 72,000-M(r) progelatinase and TIMP-2 are discussed, and the separation of the complex in 6 M-urea is described.

Differential regulation of collagenase gene expression by retinoic acid receptors--alpha, beta and gamma

The mechanisms involved in retinoic acid (RA)-mediated regulation of the collagenase gene in a rabbit synovial fibroblast cell line (HIG82) were investigated. When HIG82 cells are cotransfected with expression vectors containing cDNAs for retinoic acid receptor (RAR) alpha 1, beta 2, or gamma 1 and collagenase promoter-driven CAT reporter constructs, only RAR-gamma 1 represses basal CAT expression upon RA treatment, while RAR-alpha 1, beta 2, and gamma 1 all suppress phorbol-induced CAT expression. Thus, transcriptional regulation of collagenase by RA is mediated by RARs in an RAR-type specific manner. Using mutational and deletional analysis, we find that interaction between elements within 182 bp collagenase promoter plays an important role in this process. In addition, cotreatment with RA results in a decrease of phorbol-induced mRNA levels of fos and jun, and binding of nuclear proteins to an AP-1 oligonucleotide. Furthermore, RA-induced nuclear protein(s) specifically bind to a 22 bp sequence (-182 to -161) of the collagenase promoter. We propose that RA-mediated regulation of the collagenase gene depends on the availability and interaction of specific RARs with multiple DNA elements within the promoter and with transcription factors, including AP-1 related proteins.

Correlation of gingival crevicular fluid proteases with clinical and radiological measurements of periodontal attachment loss

Probing attachment loss and radiographical measurements of bone loss were made on 20 untreated chronic periodontitis patients. At a second visit, gingival crevicular fluid was collected on filter paper strips from the deepest accessible interdental probing site of each tooth. Gingival crevicular fluid volumes were determined and the samples eluted into buffer. Protease activities in the resulting eluates were assayed with peptidyl derivatives of 7-amino-4-trifluoromethyl coumarin (AFC). Cathepsin B/L-like activity was determined with Bz-Val-Lys-Lys-Arg-AFC, elastase-like activity with MeOSuc-Ala-Ala-Pro-Val-AFC, tryptase-like activity with Z-Ala-Ala-Lys-AFC, trypsin-like activity with Z-Gly-Gly-Arg-AFC and dipeptidyl peptidase IV-like activity with Ala-Pro-AFC. Total enzyme activities and enzyme concentrations correlated positively with probing attachment loss and bone loss in linear regression analysis. This was true at both a patient level, using mean patient values, and a site level, using either individual patient or pooled patient data. All of these correlations were highly statistically significant for site comparisons. In inter- and intra-patient comparisons the proportion of significant correlations was greater for total enzyme activity than concentration. Clinical and radiological measurements of attachment loss showed generally similar levels of correlation. Total enzyme activities had good specificity and sensitivity as indicators of attachment loss in this cross-sectional study. The results support further investigation of the diagnostic potential of gingival crevicular fluid proteases in evaluation of the periodontal condition.

Cathepsin B/L-, elastase-, tryptase-, trypsin- and dipeptidyl peptidase IV-like activities in gingival crevicular fluid. A comparison of levels before and after basic periodontal treatment of chronic periodontitis patients

20 chronic periodontitis patients were given a full periodontal examination, including measurements of probing depth, clinical attachment loss, gingival index, bleeding index and plaque index. At a second visit, gingival crevicular fluid (GCF) was collected from the deepest accessible probing site of each tooth. The patients then received scaling, root planing and other appropriate nonsurgical treatment. GCF was collected from the same sites as sampled pretreatment and clinical parameters were measured again. Cathepsin B/L-, elastase-, tryptase-, trypsin-, and dipeptidyl peptidase IV-like activities in GCF samples were determined by fluorimetric assay with peptidyl derivatives of 7-amino-4-trifluoromethyl coumarin. Following treatment, there were reductions in all clinical parameters and all protease activities. Most were statistically significant both on a patient level using average patient values and on a site level using either individual patient or pooled patient data. As in previous pre-treatment comparisons, post-treatment protease levels correlated positively and significantly with the corresponding clinical parameters at patient and site levels. The reductions and correlations were more marked for total enzyme activities than concentrations. GCF protease levels appear to reflect the clinical status of periodontal lesions and may thus be of value in monitoring disease activity.

Cathepsin B/L-, Elastase-, Tryptase-, Trypsin- and Dipeptidyl Peptidase IVLike Activities in Gingival Crevicular Fluid: A Comparison of Levels Before and After Periodontal Surgery in Chronic Periodontitis Patients

Gingival crevicular fluid (GCF) was collected from the deepest probing site of each tooth of 10 chronic periodontitis patients prior to treatment, after scaling and hygiene treatment, and after periodontal surgery. Surgery was carried out at sites which had persistent probing depths in excess of 5 mm. The patients were given a full periodontal examination, including measurements of probing depth, gingival index, bleeding index, and plaque index before each GCF collection. Cathepsin B/L-, elastase-, tryptase-, trypsin-, and dipeptidyl peptidase IV-like activities in the GCF samples were determined by fluorimetric assay with peptidyl derivatives of 7-amino-4-trifluoromethyl coumarin. There were reductions in all clinical parameters and all protease activities after scaling and hygiene treatment and further reductions after periodontal surgery. Decreases were recorded for both total enzyme activities and concentrations. The reductions were statistically significant in inter-patient comparisons using mean patient values and also in most intra-patient comparisons using site data from individual patients. GCF protease levels appear to reflect the clinical status of periodontal lesions and may prove to be of value in monitoring disease activity.

Polyunsaturated lecithin prevents acetaldehyde-mediated hepatic collagen accumulation by stimulating collagenase activity in cultured lipocytes

We recently found that polyunsaturated lecithin prevents ethanol from causing cirrhosis in the baboon. Because transformation of lipocytes to transitional cells plays a key role in hepatic fibrogenesis in vivo, and because this process in alcohol-fed baboons was found to be attenuated by polyunsaturated lecithin, we focused on lipocytes to study the mechanism of the protective effect. Rat lipocytes cultured on plastic undergo spontaneous activation, accompanied by expression of alpha-smooth muscle actin isoform and production of substantial amounts of type I collagen. The latter was further increased on incubation with acetaldehyde. This in vitro model was used here to study how acetaldehyde-mediated collagen production and accumulation can be turned off. Addition of polyunsaturated lecithin (10 mumols/L) was found to prevent the acetaldehyde-induced increase in collagen accumulation by 83% (p less than 0.001). By contrast, a saturated phospholipid (10 mumols/L dilauroyl phosphatidylcholine), a monounsaturated one (10 mumols/L linoleoyl-palmitoyl phosphatidylcholine) or linoleic acid (20 mumols/L bound to albumin) had no such effect. Incorporation of [3H]proline into collagen and the expression of alpha-1 (I) procollagen mRNA were increased by acetaldehyde; the latter was not significantly affected by polyunsaturated lecithin. Polyunsaturated lecithin increased lipocyte collagenase activity by 100% (p less than 0.001), whereas dilauroyl phosphatidylcholine, linoleoyl-palmitoyl phosphatidylcholine and linoleic acid had no such action. We concluded that (a) polyunsaturated lecithin selectively prevents the acetaldehyde-induced increase in collagen accumulation in lipocyte cultures, whereas other phospholipids or linoleate have no such effect; and (b) polyunsaturated lecithin does not modify the acetaldehyde-mediated increase in alpha-1 (I) procollagen mRNA, but it increases collagenase activity, suggesting that the protective effect exerted by polyunsaturated lecithin against alcohol induced fibrosis in vivo is due at least in part to stimulation of collagenase activity, which may prevent excess collagen accumulation by offsetting increased collagen production.

Production in Escherichia coli of porcine type-I collagenase as a fusion protein with beta-galactosidase

Porcine type-I collagenase (Colg-1) was produced as a fusion protein in Escherichia coli using the pAX5 expression vector. The fusion protein consists of beta-galactosidase at the N terminus joined to a collagen hinge region and a blood-coagulation factor Xa cleavage site linked to Colg-1. Recombinant collagenase (reColg-1) was biologically active in the form of a fusion protein and could be released by treatment with factor Xa to yield Colg-1 with the authentic N terminus (phenylalanine) found in vivo. The results show that reColg-1 produced in E. coli is folded correctly, cleaves type-I collagen into 1/4 and 3/4 fragments at the characteristic Colg-sensitive site, and is produced at high enough levels to generate a source of recombinant enzyme for x-ray crystallography studies.

Detection of Stromelysin and Collagenase in Synovial Fluid From Patients with Rheumatoid Arthritis and Posttraumatic Knee Injury

OBJECTIVE

To quantify stromelysin and collagenase in synovial fluid (SF) from patients with rheumatoid arthritis (RA) or traumatic knee injury.

METHODS

Stromelysin and collagenase were measured in the SF of 33 patients with RA or posttraumatic knee injury, using specific double-antibody sandwich enzyme-linked immunosorbent assays. Stromelysin was fractionated from representative SF, and the molecular form was identified by immunoblot analysis.

RESULTS

The stromelysin concentration was approximately 20-fold higher than the collagenase concentration in the fluids from patients with RA and approximately 8-fold higher in the fluids from patients with traumatic injury. For both metalloproteinases, there was a higher enzyme concentration in RA SF than in the SF from patients with trauma (stromelysin 40.1 +/- 26 micrograms/ml [mean +/- SD] in RA SF, 8.5 +/- 15 micrograms/ml in trauma SF; collagenase 2.2 +/- 3.3 micrograms/ml in RA SF, 1.1 +/- 2.3 micrograms/ml in trauma SF). The majority of the stromelysin within the SF bound to reactive red-agarose and was identified as prostromelysin based on electrophoretic mobility and immunoblotting with monospecific antibodies.

CONCLUSION

The finding of high levels of stromelysin in SF from patients with RA supports the proposal that this enzyme may play a role in the connective tissue degradation observed in this disease.

Cathepsin B/L-, elastase-, tryptase-, trypsin- and dipeptidyl peptidase IV-like activities in gingival crevicular fluid: correlation with clinical parameters in untreated chronic periodontitis patients

20 untreated chronic periodontitis patients were given a full periodontal examination, including measurements of probing depth (PD), clinical attachment loss (CAL), gingival index (GI), bleeding index (BI) and plaque index (Pl.I.). At a second visit, gingival crevicular fluid (GCF) was collected on filter paper strips from the deepest accessible probing site of each tooth. GCF volumes were determined and the samples eluted into buffer. Protease activities in the resulting eluates were assayed with peptidyl derivatives of 7-amino-4-trifluoromethyl coumarin (AFC). Cathepsin B/L-like activity was determined with Bz-Val-Lys-Lys-Arg-AFC, elastase-like activity with MeOSuc-Ala-Ala-Pro-Val-AFC, tryptase-like activity with Z-Ala-Ala-Lys-AFC, trypsin-like activity with Z-Gly-Gly-Arg-AFC and dipeptidyl peptidase (DPP) IV-like activity with Ala-Pro-AFC. Total enzyme activities and enzyme concentrations both correlated positively with all clinical parameters in linear regression analysis. This was true on both a patient level, using mean patient values, and a site level, using either individual patient or pooled patient data. Most of these correlations were statistically significant, although the proportion was greater for total enzyme activity than concentration. With total activities, correlations with different enzymes and parameters generally followed the order: cathepsin B/L-greater than elastase- greater than DPP IV- greater than trypsin- greater than tryptase-like activity and PD greater than CAL greater than GI greater than BI greater than Pl.I respectively. Total enzyme activities had good diagnostic specificity and sensitivity as predictors of clinical parameters in this cross-sectional study, suggesting that GCF proteases might provide useful information on the periodontal condition.