Molecular cloning of human synovial cell collagenase and selection of a single gene from genomic DNA

Association of Matrix Metalloproteinase-1 Promoter Polymorphisms With Asthma Risk

BACKGROUND/AIM

Matrix metalloproteinase-1 (MMP-1) expression has been documented as an influential contributor to the intricate milieu of allergic airway inflammation, tissue remodeling, and the exacerbation of asthma's severity. However, the genetic role underlying MMP-1 in the context of asthma has remained enigmatic, with its full implications yet to be unveiled. Considering this, our research was designed to investigate the association of MMP-1 -1607 rs1799750 and the propensity for asthma severity.

PATIENTS AND METHODS

As a case-control investigation, our study enrolled 198 individuals diagnosed with asthma and age- and sex-matched 453 non-asthmatic controls. The genotypes of MMP-1 rs1799750 were determined utilizing the polymerase chain reaction-restriction fragment length polymorphism methodology.

RESULTS

The frequency distributions of 2G/2G, 1G/2G and 1G/1G genotypes at MMP-1 rs1799750 were 49, 42.9, and 8.1%, respectively, among the patients with asthma. This pattern was not different from that of controls (43.7, 46.8, and 9.5%, respectively) (p for trend=0.4486). The allelic frequency pertaining to the variant 1G allele within the asthma group was 29.5%, with a non-significant disparity compared to the 32.9% in the control group (p=0.2596). Noticeably, there was a positive association between MMP-1 rs1799750 2G/1G and 1G/1G genotypes with asthma severity (p=0.0060).

CONCLUSION

Our research indicated that the presence of MMP-1 rs1799750 1G allele might not be the sole arbiter of an individual's susceptibility to asthma, yet its potential to function as a discerning prognostic marker for the severity of asthma emerged as a noteworthy finding deserving attention and further exploration.

Anti-aging effects of Piper cambodianum P. Fourn. extract on normal human dermal fibroblast cells and a wound-healing model in mice

Background

Aging of skin is associated with environmental factors such as ultraviolet rays, air pollution, gravity, and genetic factors, all of which can lead to wrinkling of skin. Previous reports suggest that the wound repair is impaired by the aging process and strategies to manipulate the age-related wound healing are necessary in order to stimulate repair.

Objective

Several traditional plant extracts are well-known for their properties of skin protection and care. Piper cambodianum P. Fourn. (PPF), a member of Piperacecae, is a plant found in Vietnam that might have therapeutic properties. Therefore, the effects of PPF stem and leaf extract on aging process were investigated in vitro and in vivo.

Methods

PPF extract dissolved in methanol was investigated using Western blotting, real-time quantitative reverse transcription-polymerase chain reaction, flow cytometry, and cell wound-healing assays. We assessed the anti-aging effect of PPF in mouse using the wound-healing assay. The results were analyzed by Student’s unpaired t-test; *P<0.05 and **P<0.01 were considered to indicate significant and highly significant values, respectively, compared with corresponding controls.

Results

PPF treatment demonstrated in vitro and in vivo anti-aging activity. Western blot analysis of PPF-treated normal human dermal fibroblast cells showed a dose-dependent increase in the expression of extracellular matrix genes such as collagen and elastin, but decreased expression of the aging gene matrix metalloproteinase-3. Quantitative polymerase chain reaction showed that PPF-treated cells displayed dose-dependent increase in messenger RNA expression levels of collagen, elastin, and hyaluronan synthase-2 and decreased expression levels of matrix metalloproteinase-1 aging gene. PPF treatment led to decreased production of reactive oxygen species in cells subjected to ultraviolet irradiation. Furthermore, PPF extract showed positive wound-healing effects in mice.

Conclusion

This study demonstrated the anti-aging and wound-healing effects of PPF extract. Therefore, PPF extract represents a promising new therapeutic agent for anti-aging and wound-healing treatments.

Osteopontin is highly expressed in severely dystrophic muscle and seems to play a role in muscle regeneration and fibrosis

AIMS

To increase our understanding of profibrotic mechanisms in dystrophic muscle.

METHODS AND RESULTS

Extracellular matrix, fibrosis-related molecules and histopathology were assessed in skeletal muscle of patients with Duchenne muscular dystrophy (DMD), Becker muscular dystrophy (BMD), and congenital muscular dystrophy type 1A (MDC1A).Osteopontin expression was much higher in DMD and MDC1A than in BMD and control muscle. Osteopontin was expressed in mononuclear cell infiltrates, on some muscle fibre surfaces, in regenerating fibres, and in calcified fibres. In all pathological muscles, matrix metalloproteinase (MMP)-1 was increased around groups of fibres that were also characterized by absence of collagen 1. The amounts of MMP-2, MMP-9 and tissue inhibitor of MMP -1 transcripts were also increased, whereas their proteins were variably expressed in muscle fibres (surface or cytoplasm) and at foci of necrosis and regeneration. Inflammatory cells, fibroblasts and myofibroblasts were more numerous in DMD and MDC1A than in BMD muscle.

CONCLUSIONS

Several fibrosis-related factors are greatly altered in severely dystrophic skeletal muscle. Osteopontin was the most conspicuously upregulated, both as transcript and as protein, in muscle fibres and infiltrating cells, indicating an intimate involvement in fibrosis, and also in inflammation and muscle regeneration, although its precise roles in these processes remain to be elucidated.

Crosstalk between neovessels and mural cells directs the site-specific expression of MT1-MMP to endothelial tip cells

The membrane-anchored matrix metalloproteinase MT1-MMP (also known as Mmp14) plays a key role in the angiogenic process, but the mechanisms underlying its spatiotemporal regulation in the in vivo setting have not been defined. Using whole-mount immunohistochemical analysis and the lacZ gene inserted into the Mmp14 gene, we demonstrate that MT1-MMP vascular expression in vivo is confined largely to the sprouting tip of neocapillary structures where endothelial cell proliferation and collagen degradation are coordinately localized. During angiogenesis in vitro, wherein endothelial cells are stimulated to undergo neovessel formation in the presence or absence of accessory mural cells, site-specific MT1-MMP expression is shown to be controlled by crosstalk between endothelial cells and vascular smooth muscle cells (VSMC). When vessel maturation induced by VSMCs is inhibited by introducing a soluble form of the receptor tyrosine kinase Tek, MT1-MMP distribution is no longer restricted to the endothelial tip cells, but instead distributes throughout the neovessel network in vitro as well as ex vivo. Taken together, these data demonstrate that vascular maturation coordinated by endothelial cell/mural cell interactions redirects MT1-MMP expression to the neovessel tip where the protease regulates matrix remodeling at the leading edge of the developing vasculature.

The role of matrix metalloproteinase genes in glioma invasion: co-dependent and interactive proteolysis

Matrix metalloproteinases (MMPs) are cation-dependent endopeptidases which have been implicated in the malignancy of gliomas. It is thought that the MMPs play a critical role in both metastasis and angiogenesis, and that interference with proteases might therefore deter local tumor dissemination and neovascularization. However, the attempt to control tumor-associated proteolysis will rely on better definition of the normal tissue function of MMPs, an area of study still in its infancy in the central nervous system (CNS). Understanding the role of MMP-mediated proteolysis in the brain relies heavily on advances in other areas of molecular neuroscience, most notably an understanding of extracellular matrix (ECM) composition and the function of cell adhesion molecules such as integrins, which communicate knowledge of ECM composition intracellularly. Recently, protease expression and function has been shown to be strongly influenced by the functional state and signaling properties of integrins. Here we review MMP function and expression in gliomas and present examples of MMP profiling studies in glioma tissues and cell lines by RT-PCR and Western blotting. Co-expression of MMPs and certain integrins substantiates the gathering evidence of a functional intersection between the two, and inhibition studies using recombinant TIMP-1 and integrin antisera demonstrate significant inhibition of glioma invasion in vitro. Use of promising new therapeutic compounds with anti-MMP and anti-invasion effects are discussed. These data underline the importance of functional interaction of MMPs with accessory proteins such as integrins during invasion, and the need for further studies to elucidate the molecular underpinnings of this process.

The role of matrix metalloproteinase genes in glioma invasion: co-dependent and interactive proteolysis

Matrix metalloproteinases (MMPs) are cation-dependent endopeptidases which have been implicated in the malignancy of gliomas. It is thought that the MMPs play a critical role in both metastasis and angiogenesis, and that interference with proteases might therefore deter local tumor dissemination and neovascularization. However, the attempt to control tumor-associated proteolysis will rely on better definition of the normal tissue function of MMPs, an area of study still in its infancy in the central nervous system (CNS). Understanding the role of MMP-mediated proteolysis in the brain relies heavily on advances in other areas of molecular neuroscience, most notably an understanding of extracellular matrix (ECM) composition and the function of cell adhesion molecules such as integrins, which communicate knowledge of ECM composition intracellularly. Recently, protease expression and function has been shown to be strongly influenced by the functional state and signaling properties of integrins. Here we review MMP function and expression in gliomas and present examples of MMP profiling studies in glioma tissues and cell lines by RT-PCR and Western blotting. Co-expression of MMPs and certain integrins substantiates the gathering evidence of a functional intersection between the two, and inhibition studies using recombinant TIMP-1 and integrin antisera demonstrate significant inhibition of glioma invasion in vitro. Use of promising new therapeutic compounds with anti-MMP and anti-invasion effects are discussed. These data underline the importance of functional interaction of MMPs with accessory proteins such as integrins during invasion, and the need for further studies to elucidate the molecular underpinnings of this process.

Transcriptional repression of the human collagenase-1 (MMP-1) gene in MDA231 breast cancer cells by all-trans-retinoic acid requires distal regions of the promoter

In the present study, we investigated the mechanisms controlling constitutive transcription of collagenase-1 and its repression by all-trans-retinoic acid (RA) in the highly invasive metastatic and oestrogen-receptor-negative breast cancer cell line MDA231. A combination of in vivo and in vitro experiments that include DNAase I hypersensitivity assays, transient transfection of collagenase-1 promoter constructs, and electrophoretic mobility shift assays implicate several PEA3 sites, binding sites for Ets-related transcription factors, in the constitutive expression of the human collagenase-1 promoter. Transient transfection of promoter constructs linked to the luciferase reporter, along with gel retardation assays, revealed that repression of collagenase-1 transcription by RA is not dependent on the proximal AP-1 site, but, rather, requires sequences located in distal regions of the promoter. Transcriptional analyses and electrophoretic mobility shift assays suggest that the PEA3 site located at -3108 bp facilitates, at least in part, the transcriptional repression of the human collagenase-1 gene in MDA231 cells. We conclude that collagenase-1 repression in MDA231 cells occurs by a novel regulatory pathway that does not depend on the proximal AP-1 site at -73 bp, but does depend on distal regions in the collagenase-1 promoter.

Interleukin-1 beta induces differential gene expression in aortic smooth muscle cells

PURPOSE

Abdominal aortic aneurysms are characterized by an accelerated turnover of extracellular matrix proteins and by an inflammatory infiltrate that releases the cytokines interleukin-1 beta and tumor necrosis factor-alpha. We examined the gene expression of human aneurysmal aortic smooth muscle cells and normal aortic smooth muscle cells after treatment with interleukin-1 beta and tumor necrosis factor-alpha by measuring the changes in smooth muscle cell collagen, elastin, collagenase, and tissue inhibitor of metalloproteinase messenger ribonucleic acid levels in response to these cytokines.

METHODS

Biopsy of aneurysmal aorta (n = 6) and donor normal aorta (n = 3) was obtained at operation. Medial smooth muscle cells were cultured, passaged (P2 to P4), and incubated with 0, 10, 100, or 1000 pg/ml interleukin-1 beta, tumor necrosis factor-alpha, or platelet-derived growth factor for 24 hours. Total ribonucleic acid was harvested. Percentage changes in messenger ribonucleic acid from control levels for type I and type III procollagen, elastin, collagenase, 72 kDa type IV collagenase, tissue inhibitor of metalloproteinase-1, and tissue inhibitor of metalloproteinase-2 were measured by Northern hybridization. Analyses were performed with analysis of variance (p < 0.05). All comparisons between aneurysmal aortic smooth muscle cells and normal aortic smooth muscle cells represent comparisons between one aneurysmal aorta and one normal aorta.

RESULTS

Added interleukin-1 beta resulted in significant, dose-dependent increases in the collagenase messenger ribonucleic acid level at all concentrations tested in both aneurysmal aorta and normal aorta. The increase in the collagenase messenger ribonucleic acid level ranged from a minimum increase of 123% for 10 pg/ml interleukin-1 beta in aneurysmal aortic smooth muscle cells to a maximum of 450% for 1000 pg/ml interleukin-1 beta in normal aortic smooth muscle cells. Interleukin-1 beta caused a significant decrease in the steady-state messenger ribonucleic acid levels for type 1 procollagen in both aneurysmal and normal aorta. The greatest reduction in type 1 procollagen messenger ribonucleic acid levels occurred at 100 pg/ml interleukin-1 beta in both aneurysmal aortic smooth muscle cells (-39%) and normal aortic smooth muscle cells (-48%). The only observed qualitative difference between aneurysmal aortic smooth muscle cells and normal aortic smooth muscle cells was the change in tissue inhibitor of metalloproteinase-1 messenger ribonucleic acid levels in response to added interleukin-1 beta. In aneurysmal aortic smooth muscle cells interleukin-1 beta at 1000 pg/ml significantly increased messenger ribonucleic acid levels by 82%, whereas levels of tissue inhibitor of metalloproteinase-1 messenger ribonucleic acid in normal aortic smooth muscle cells did not change in response to added interleukin-1 beta. Interleukin-1 beta did not alter messenger ribonucleic acid levels for type III procollagen, elastin, type IV collagenase, or tissue inhibitor of metalloproteinase-2 in aneurysmal aorta or normal aorta. When tumor necrosis factor-alpha or platelet-derived growth factor were added, this did not significantly change aneurysmal aortic smooth muscle cells messenger ribonucleic acid levels for collagenase, type IV collagenase, tissue inhibitor of metalloproteinase-1, tissue inhibitor of metalloproteinase-2, and type I and type III procollagen.

CONCLUSIONS

These findings suggest that interleukin-1 beta, through its effect on smooth muscle cell collagenase and collagen gene expression, mediates the increased matrix turnover observed in aneurysms. Macrophages may induce changes in aortic smooth muscle cell gene expression in a paracrine manner that could lead to aneurysm formation.

Induction of collagenase and stromelysin gene expression by mechanical injury in a vascular smooth muscle-derived cell line

We describe a novel system for studying the production of matrix metalloproteinases types I and III (collagenase and stromelysin) by a vascular smooth muscle cell line (Rb-1 cells) in response to mechanical injury. Highly confluent Rb-1 cells are disrupted by passing a plastic comb around the plate to clear a series of circumferential paths, which are bordered by two ridges of displaced cells. Over the next 24 hours, cells migrate into the cleared areas. Northern blot analysis demonstrates the accumulation of mRNAs for collagenase and stromelysin during this process, although they are undetectable prior to injury. Cotreatment with all-trans-retinoic acid (10(-6) M) markedly decreases the level of mRNAs induced by injury, whereas dexamethasone (10(-7) M) causes only a slight reduction. In situ hybridization studies for stromelysin mRNA and immunohistochemical staining for collagenase protein on plates of injured cells showed the highest levels of stromelysin mRNA in cells in the ridges left by the injury; lower levels were observed in some cells migrating into the clear region. The same pattern of expression was observed when cells were stained with antiserum to collagenase protein. Nuclear run-on assays demonstrated increases in transcription of stromelysin and collagenase genes following injury. Transient transfection of cells with a vector containing the luciferase gene driven by a wild-type promoter comprising 1.8 kb of the 5'-flanking region of the rabbit collagenase gene showed increased activity associated with injury. We conclude that: (1) mechanical injury is associated with induction of mRNAs for the metalloproteinases collagenase and stromelysin, (2) retinoic acid effectively antagonizes this responses, and (3) the increase in steady-state mRNA levels is, at least in part, transcriptionally mediated. Thus our data suggest a role for mechanical forces in initiating the changes in gene expression in vascular smooth muscle cells following arterial injury in vivo.

Gene expression of collagenase and stromelysin in skin fibroblasts derived from dystrophic epidermolysis bullosa

We studied expression of collagenase gene and stromelysin gene in skin fibroblasts derived from patients with recessive dystrophic epidermolysis bullosa (RDEB) and dominant dystrophic epidermolysis bullosa (DDEB). Northern blot analyses revealed that collagenase gene expression was markedly increased in two of four RDEB cells, as compared with three normal control cells. Moreover, stromelysin gene expression was also markedly increased in two RDEB cells, as compared with normal controls. In contrast, collagenase and stromelysin gene expression levels in three DDEB cells did not show any significant difference from those of normal controls, except one cell line which showed mild increase of both collagenase and stromelysin mRNA. Quantitative estimates of collagenase mRNA (U/micrograms RNA) determined by slot blot hybridizations showed that those of RDEBs: 0.92-1.81 (mean 1.3 +/- 0.45); DDEBs: 0.18-0.73 (mean 0.60 +/- 0.37); normal controls: 0.26-0.93 (mean 0.64 +/- 0.34). Stromelysin mRNA levels showed that those of RDEBs: 1.75-6.62 (mean 4.06 +/- 2.00); DDEBs: 0.55-3.78 (mean 1.69 +/- 1.81); normal controls: 1.27-2.08 (mean; 1.55 +/- 0.45). These data demonstrated that collagenase and stromelysin gene expression was increased in some, but not all, RDEB cell lines. Our data suggested that collagenase and/or stromelysin could play a certain role for blister formation in RDEB, coordinately or in a distinct manner.

Novel phorbol ester response region in the collagenase promoter binds Fos and Jun

In rabbit fibroblasts the AP-1 sequence (5'-ATGAGTCAC-3') is necessary but not sufficient for induction of collagenase transcription by phorbol esters (PMA) (Auble and Brinckerhoff: Biochemistry 30(18):4629-4635, 1991). In this study we identified additional sequences involved in PMA-induced transcription. Using fibroblasts transiently transfected with chimeric constructs containing fragments of the rabbit collagenase 5'-flanking DNA linked to the chloramphenicol acetyl transferase (CAT) gene, we found that deletion of nucleotides -182 to -141 in a 380 bp promoter construct resulted in about a 7-fold loss of induction by PMA. Mobility shift assays revealed that nuclear proteins from fibroblasts specifically bound to 20-bp at -182 to -161. Binding was competed completely by self and only partially by the AP-1 sequence, implying that proteins binding to the AP-1 sequence could also bind to this region. In vitro transcribed and translated c-Fos and c-Jun bound to both the AP-1 site and to the sequences from -182 to -141. DNAase I footprinting of the collagenase promoter with purified c-Jun or c-Fos/c-Jun protected the AP-1 sequence at -77 to -69 in addition to a region from -189 to -178 which overlaps a putative AP-1-like site, 5'-ATTAATCAT-3'. Finally, deletion of the -182 to -161 region in a 380-bp CAT construct resulted in a substantial reduction of PMA responsiveness. Thus, we have identified a novel phorbol-responsive region that binds c-Fos and c-Jun, and we suggest that these or similar proteins may regulate transcription of the collagenase gene by binding to sequences within and adjacent to the -182 to -161 region.

Interaction of the terminal complement components C5b-9 with synovial fibroblasts: binding to the membrane surface leads to increased levels in collagenase-specific mRNA

The late complement components, apart from their lytic function, are known to trigger the release of various proinflammatory substances from different types of nucleated cells. In the present study, the interaction of C5b-9 with synovial fibroblast cells (SFC) was examined. It was found that incubation of SFC with activated complement components resulted in binding of C5b-9 to the cell membrane; subsequently an increase in abundance of collagenase-specific mRNA was seen, as assessed by Northern blotting. When C8-deficient serum was used as source of complement neither binding of C5b-9 nor an increase in collagenase-specific mRNA could be detected. These findings suggest that C5b-9, which might be generated during rheumatoid inflammation, may contribute to chronic joint destruction by triggering collagenolytic activity.

Post-transcriptional regulation of collagenase and stromelysin gene expression by epidermal growth factor and dexamethasone in cultured human fibroblasts

Epidermal growth factor (EGF) is a ubiquitous fibroblast mitogen which also stimulates the synthesis of the extracellular matrix degrading metalloproteinases, collagenase, and stromelysin. Using primary cultures of human skin fibroblast, we show that these metalloproteinase mRNAs are coordinately up-regulated by EGF; and that dexamethasone, a potent inhibitor of collagenase and stromelysin synthesis, coordinately down-regulates these EGF-induced mRNAs. Nuclear run-on assays showed that EGF increased transcription of collagenase and stromelysin approximately 2-fold over the untreated control, while repression by dexamethasone was difficult to detect. However, steady state mRNA levels were induced approximately 10-fold by EGF and co-treatment with dexamethasone decreased them to below control levels, suggesting modulation of mRNA stability. Thus, we measured the half-life of these mRNAs using "pulse-chase" methodology. Typically, the half-life of EGF-induced collagenase and stromelysin mRNAs was approximately 30 h, and co-treatment with dexamethasone decreased the half-life of these mRNAs by 30-50%. Additionally, we found that the transcription inhibitor DRB stabilized EGF-induced metalloproteinase mRNAs, suggesting an mRNA degradation pathway which requires transcription. Thus our data demonstrate that collagenase and stromelysin are coordinately regulated by EGF and by dexamethasone, primarily at the level of metalloproteinase mRNA stability.

Structural characterization of the mesangial cell type IV collagenase and enhanced expression in a model of immune complex-mediated glomerulonephritis

Secretion of glomerular cell-derived matrix metalloproteinases (MMPs) and their specific inhibitors, TIMP-1,2, may play an important role in the turnover of the glomerular extracellular matrix under basal and pathologic conditions. A 66-68 kd MMP secreted by cultured mesangial cells (MC) with activity against Type IV collagen and gelatin was purified and shown by amino-acid sequence analysis to be identical with a Type IV collagenase/gelatinase secreted by certain transformed tumor cell lines. The expression of the mesangial MMP in vivo was limited within the kidney to a small subset of the intrinsic glomerular mesangial cell population. After induction of acute anti-Thy 1.1 glomerulonephritis, there was a large increment in the number of Type IV collagenase-secreting MC, temporally coincident with the development of mesangial hypercellularity. The expression of the MMP inhibitor protein, TIMP-1, was not changed over this period. Ultrastructural studies localized the mesangial MMP to areas of evolving mesangiolysis and at sites of glomerular basement membrane disruption. Enhanced expression of the mesangial cell-derived Type IV collagenase may contribute to the evolution of glomerular injury in this model of immune complex-mediated glomerulonephritis or may be involved in the extensive matrix remodeling process that accompanies this form of glomerular injury.

Mercurial activation of human polymorphonuclear leucocyte procollagenase

The mechanism of human polymorphonuclear leucocyte (PMNL) procollagenase activation by HgCl2 was investigated by kinetic and sequence analysis of the reaction products. HgCl2 activated PMNL procollagenase by intramolecular autoproteolytic cleavage of the Asn53-Val54 peptide bond to generate a collagenase species of Mr 65000, which was immediately converted into a second intermediate collagenase form by further autoproteolytic cleavage of the Asp64-Met65 peptide bond within the propeptide domain. This intermediate form (Met65 N-terminus) reached maximum concentrations after 45 min and displayed only about 40% of the maximum available enzymatic activity. Final activation was obtained after autoproteolytic cleavage of either Phe79-Met80 or Met80-Leu81 peptide bonds. Furthermore, activation in the presence of TIMP-1 did not suppress the intramolecular autoproteolytic cleavage of the Asn53-Val54 peptide bond. Complete inhibition of further autoproteolytic decay of the enzyme or generated peptides was observed, which was obviously due to complex formation between the intermediate collagenase form (Val54 N-terminus) and inhibitor, which was visualized using the Western blot technique. Thus PMNL procollagenase activation by HgCl2 followed a three-step activation mechanism which is entirely different from the known activation mechanisms of the fibroblast matrix metalloproteinases.

Substrate specificity and activation mechanisms of collagenase from human rheumatoid synovium

Substrate specificity studies of collagenase extracted from human rheumatoid synovium suggest that synovial pannus tissue overlying articular cartilage may not be particularly active in degradation of cartilage type II collagen, which, considering the poor inherent healing capacity of the articular hyaline cartilage, may exert a protective function against inadvertant tissue damage. Rheumatoid synovial tissue was also used to establish synovial fibroblast cell lines. Treatment of these cells in monolayer cultures with IL-1 leads to collagenase gene activation, increased collagenase production and an almost complete autoactivation of secreted collagenase. Interleukin-1 also activated stromelysin gene suggesting this as a possible mechanism effecting autoactivation. Latent human fibroblast and macrophage collagenase purified from culture medium were efficiently activated by phenylmercuric chloride but also by gold thioglucose, gold sodium thiomalate and HCIO. These new observations support the Cys73 switch activation mechanism. In contrast to neutrophil collagenase, the activation by gold(I) compounds and HCIO was associated with a change in the apparent molecular weight of the fibroblast procollagenase. In addition, gold(I) compounds rendered collagenase more susceptible to thermal denaturation. Thus the fibroblast-type interstitial collagenase, probably derived from fibroblast- and macrophage-like synoviocytes, seems to provide the predominant collagenolytic potential in human rheumatoid synovial tissue. Furthermore, the conditions in synovitis tissue may be such as to favor at least initial activation of collagenase synthesized and secreted in situ.

Purification to homogeneity of latent and active 58-kilodalton forms of human neutrophil collagenase

Latent and active 58-kDa forms of human neutrophil collagenase (HNC) have been purified to homogeneity. Buffy coats were extracted in the presence and absence of phenylmethanesulfonyl fluoride to generate crude starting preparations that contained latent and active HNC, respectively. The buffers used in preparing these extracts and for all subsequent chromatographic steps contained NaCl at a concentration of 0.5 M or greater, 0.05% Brij-35, concentrations of CaCl2 of 5 mM or greater, and (when feasible) 50 microM ZnSO4 to stabilize the HNC. The collagenase activity in the buffy coat extracts was adsorbed to a Reactive Red 120-agarose column at pH 7.5 in 0.5 M NaCl and was eluted when the NaCl concentration was increased to 1 M. The active and p-(chloromercuri)benzoate-activated latent enzymes were next adsorbed to a Sepharose-CH-Pro-Leu-Gly-NHOH affinity resin in 1 M NaCl at pH 7.5 and desorbed at pH 9 to give a fraction containing only HNC and a small amount of neutrophil gelatinase. The latter enzyme was removed by passage over a gelatin-Sepharose column in 1 M NaCl at pH 7.5. The purified samples of active and latent HNC were obtained with typical cumulative yields of 32 and 82% and specific activities toward soluble rat type I collagen at 30 degrees C of 7200 and 12,000 micrograms min-1 mg-1, respectively. These specific activities are markedly higher than previously reported for HNC. Both active and latent HNC exhibit a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis both in the presence and in the absence of 2-mercaptoethanol. The mobility of latent HNC is consistent with a molecular weight of approximately 58K, with the active form exhibiting a slightly lower (less than 1-2K) molecular weight.

Secretion and glycosylation of rabbit macrophage type V collagenase

Cultures of freshly isolated rabbit alveolar macrophages were used to study the synthesis, secretion, and glycosylation of type V collagenase. Cells were pulse-labeled with [35S-]methionine for 15 minutes followed by a chase with cold methionine for various time periods. Type V collagenase was identified in the culture supernatants and cell lysates by immunoprecipitation with a specific antiserum. Within 10 minutes of chase, an 82-kDa protein was found in the cell lysates. This protein was subsequently processed to a 92-kDa protein without identifiable intermediate forms. By 60 minutes of chase, intracellular radioactivity was no longer detectable. The larger protein could be detected within 20 minutes in the culture supernatants and accumulated in the medium for 60 minutes of chase time. Only the 92-kDa form was seen in the supernatants and the proteinase was secreted without intracellular storage or membrane association. Treatment of the 92-kDa proteinase with an enzyme which specifically removes N-linked carbohydrates resulted in an apparent reduction in molecular mass of approximately 10 kDa. Deglycosylation of the proteinase did not result in an apparent loss of activity. Thus, it was concluded that macrophage type V collagenase is synthesized as an 82-kDa polypeptide which is glycosylated by N-linkage and secreted.

Characterization and activation of procollagenase from human polymorphonuclear leucocytes. N-terminal sequence determination of the proenzyme and various proteolytically activated forms

Procollagenase of human polymorphonuclear leucocytes was purified to homogeneity using a rapid and reproducible method. The purification procedure included affinity chromatography on zinc chelate Sepharose, ion exchange chromatography on Q-Sepharose fast flow, followed by affinity chromatography on orange Sepharose and finally a gel-permeation step on Sephacryl S-300. It was shown by SDS/PAGE, under reducing conditions, that the latent collagenase of human polymorphonuclear leucocytes consists of a single polypeptide chain with an apparent relative molecular mass of 85,000. Upon deglycosylation by endoglycosidase F digestion, the apparent relative molecular mass of the procollagenase was reduced to 53,000 which is similar to that of the fibroblast enzyme, and indicates a close relationship between both enzymes. Sequence data were determined by direct automated Edman degradation of the purified polymorphonuclear leucocyte procollagenase. The complete sequence of the propeptide region (residue 1-120) was thereby established. The proteolytic activation of the polymorphonuclear leucocyte procollagenase by various enzymes was investigated by determining the N-terminal sequences of the intermediate and final activated forms. Activation by chymotrypsin and cathepsin G led to the active form (Mr 64,000) by cleaving 79 N-terminal residues from the proenzyme. Trypsin activates in a two-step process. Cleavage of 48 N-terminal residues led to a still latent Mr 70,000 species. The final active form (Mr 65,000) was obtained by splitting off 20 additional N-terminal residues.

Localization of collagenase mRNA in rheumatoid arthritis synovium by in situ hybridization histochemistry

Collagenase has been implicated as playing an important role in the connective tissue destruction that is a major feature of rheumatoid arthritis. Numerous cell types in the hyperplastic rheumatoid synovium are capable of synthesizing collagenase. Past studies have used predominantly synovial fibroblasts in culture as a model system for the regulation of collagenase production, but the major cellular source of the enzyme in vivo has not been determined. Using the techniques of in situ hybridization histochemistry and indirect immunofluorescence, we determined the cellular source of collagenase in frozen sections of human synovium. Collagenase mRNA production was localized to cells along the synovial lining layer in rheumatoid arthritis. These were identified as the macrophage-like Type A synovial lining cells by immunofluorescence with antibody LeuM3. Endothelial cells, fibroblasts, and T and B lymphocytes were devoid of detectable collagenase mRNA. Synovial tissue sections from patients with osteoarthritis and trauma did not contain detectable collagenase mRNA. These data identify the Type A macrophage-like synovial lining cell as the primary source of collagenase mRNA in vivo in the rheumatoid arthritis synovium and, potentially, as a major effector cell in the tissue destruction of the disease.

Cloning of the genes for human stromelysin and stromelysin 2: differential expression in rheumatoid synovial fibroblasts

Stromelysin is a member of a gene family of metalloproteinases involved in extracellular matrix remodeling in normal and diseased processes. Primary cultures of rheumatoid synovial cells produce large amounts of metalloproteinase mRNA and proteins. We cloned a cDNA for human stromelysin from a rheumatoid synovial cell cDNA library, and we used the cDNA to isolate the gene for human stromelysin and a related gene, stromelysin 2. We sequenced parts of the genes and found that both are contained on approximately 14 kilobase pairs of DNA. Using an exon-containing fragment of the stromelysin 2 genomic clone as a specific probe in Northern blot analysis, we demonstrate the differential expression of stromelysin and stromelysin 2 in rheumatoid synovial cells, human foreskin fibroblasts, and rabbit synovial fibroblasts. In addition, using chimeric constructs of the stromelysin promoter linked to the bacterial gene chloramphenicol acetyltransferase (CAT), we show that the elements required for the tumor promoter phorbol myristate acetate (PMA), epidermal growth factor (EGF), and interleukin 1 beta (IL-1 beta) induction are contained on a 307 base pair fragment which includes approximately 270 base pairs (bp) of 5'-flanking DNA. The cloning of the human stromelysin and stromelysin 2 genes, the documentation of their differential expression, and the identification of transcriptional regulatory regions in the stromelysin gene will facilitate the study of metalloproteinase gene expression in normal processes and in diseases such as rheumatoid arthritis.

Regulation of collagenase and collagenase mRNA production in early- and late-passage human diploid fibroblasts

The levels of collagenase and collagenase mRNA produced by early-passage (less than 40% of lifespan completed) and late-passage (greater than 80% of lifespan completed) cultures of human fibroblasts were analyzed. The constitutive levels of collagenase and collagenase mRNA produced by the late-passage cultures were 10-30 x greater than the levels observed in similarly treated early-passage cultures. Immunofluorescence analysis established that the percentage of collagenase-positive cells was also greater (77% vs. 4%) in the late-passage cultures. To determine whether the difference in collagenase production resulted from cell-derived regulatory factors, collagenase production was examined in cultures plated onto substrates coated with fibroblast extracellular matrix (ECM). Collagenase and collagenase mRNA production was enhanced in both types of cultures, although amounts produced by ECM-induced early-passage cultures was significantly less than that produced by similarly treated late-passage cultures. Collagen-coated substrates also induced collagenase synthesis.

Collagenase production by early and late passage cultures of human fibroblasts

Comparison of the proteins secreted by early and late passage cell cultures of human fibroblasts revealed a high level of immunoreactive collagenase (Mr = 55,000 Da and 58,000 Da) in the late passage cell culture conditioned medium. Both molecular weight species reacted with a monoclonal anticollagenase antibody and were apparently glycosylation varaents of the same protein. The question of whether the apparent age-dependent differences in collagenase synthesis reflected changes in protein synthesis or secretion was addressed by assaying immunoreactive collagenase and collagenase mRNA. Immunofluorescence microscopy of cellular collagenase revealed that the percentage of collagenase positive cells ranged from 1 to 6% (early passage) to 35 to 46% (late passage) indicating that the late passage cells had higher basal levels of collagenase synthesis. Later passage cultures also secreted higher levels of immunoprecipitable collagenase into the culture medium and Northern analysis established that the basal level of collagenase mRNA was also 10 times greater in late passage cells. High basal levels of collagenase were also observed in fibroblasts cultured from an in vivo aged donor and from donors with Werner's syndrome. Collagenase production was induced in both early and late passage cell cultures by exposure to fibroblast extracellular matrix, fibroblast conditioned media, polypeptide growth factors, or phorbol esters. The induced levels were always greater in the late passage cell cultures than in the early passage cell cultures.

Autocrine control of collagenase synthesis by synovial fibroblasts

Fibroblasts respond to exogenous stimuli, such as Interleukin 1, phorbol esters, or crystals of monosodium urate monohydrate, by synthesizing and secreting large quantities of collagenase. Here we show that addition of exogenous stimuli results in the production of an autologous protein that is, itself, capable of inducing collagenase. This autocrine has been partially purified. Activity resides in a protein(s) with a pl of 5 or 8 and with Mr of approximately 15K. Conversely, conditioned medium taken from unstimulated cultures contains an inhibitor of collagenase synthesis. This protein, which has a Mr approximately 20-25k by HPLC gel filtration antagonizes collagenase synthesis induced by phorbol esters, exogenous parallel 1, and the autologous inducer. We conclude that synovial fibroblasts regulate collagenase synthesis via an autocrine mechanism that includes the synthesis of both an inducer and inhibitor. Both proteins are active at nanomolar amounts and may function as polypeptide hormones in regulating collagenase synthesis and, hence, connective tissue remodeling.

Restriction fragment length polymorphism analysis and assignment of the metalloproteinases stromelysin and collagenase to the long arm of chromosome 11

Collagenase and stromelysin are two metalloproteinases produced mainly by connective tissue cells and involved in the breakdown of the extracellular matrix. cDNA clones for both of these genes have been isolated and sequencing has shown them to be closely related. The collagenase and stromeylsin cDNA clones have been used to assign these genes to the long arm of chromosome 11 in the regions 11q21-22.1 and 11q22.2-22.3, respectively. This has been achieved using somatic cell hybrids and in situ hybridization. In addition a Taq1 restriction fragment length polymorphism has been demonstrated using the stromelysin cDNA.