A neutral protease in rheumatoid synovial fluid capable of attacking the telopeptide regions of polymeric collagen fibrils

Steven, F. S.; Torre-Blanco, Alfonso; Hunter, John

doi:10.1016/0005-2795(75)90329-3

Cited by 48 publications

(29 citation statements)

References 17 publications

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“…This fluorescent substrate was chosen on account of its internal labelling and the need to ensure that the reaction products were derived from the added substrate rather than from the digestion of proteoglycans in the crude extract. The experimental conditions with fluoresceinlabelled casein were identical to those described for casein, except that the fluorimetry was carried out with an excitation wavelength of 495 nm and emission at 520 nm (Steven et al, 1975 (1966). In these experiments a series of control tubes were included which contained trypsin or cells but with no inhibitor added.…”

Section: Methodsmentioning

confidence: 99%

A trypsin-like neutral protease on Ehrlich ascites cell surfaces: its role in the activation of tumour-cell zymogen of collagenase

Steven¹,

Griffin²,

Itzhaki³

et al. 1980

Br J Cancer

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Summary.-Ehrlich ascites cells in mice have been shown to have a cell-surface trypsin-like neutral protease (TLNP) with proteolytic and p-naphthylamidase activity. This activity is inhibited by low-mol.-wt inhibitors of trypsin but not by 11 high-mol. -wt inhibitors of trypsin in free solution. We believe this lack of inhibition is due to protection given to the enzyme by the chemical environment of the cell surface. These cells were demonstrated to export a collagenase zymogen which has been shown to be activated by the cell-surface TLNP. When this protease was completely inhibited by low-mol.-wt inhibitors of trypsin, chymotrypsin was used to activate the collagenase zymogen exported by Ehrlich ascites cells. Examination of the products of collagenolysis at 15°C demonstrated the expected 3-and 4-length a-chain fragments derived from monomeric collagen, confirming that collagenase was one of the enzymes responsible for lysis of the collagen fibrils in the test system.

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Section: Methodsmentioning

confidence: 99%

A trypsin-like neutral protease on Ehrlich ascites cell surfaces: its role in the activation of tumour-cell zymogen of collagenase

Steven¹,

Griffin²,

Itzhaki³

et al. 1980

Br J Cancer

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“…, (b) these PMN leukocytes release elastase (3) as well as a number of other enzymes and inflammatory mediators (4) during phagocytosis or other mechanisms (5), (c) substantial quantities of elastase have been identified in the synovium (6,7) or, complexed to naturally occuring inhibitors in synovial fluids of RA patients (8)(9)(10)(11)(12) or penetrated into the articular cartilage (13,14).…”

mentioning

confidence: 99%

Plasma Levels of Inhibitor-Bound Leukocytic Elastase in Rheumatoid Arthritis Patients

Schnebli

Christen

Jochum

et al. 1984

Advances in Experimental Medicine and Biology

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“…Lysosomal proteinases (22), proteinases acting at neutral pH (12)(13)(14)16,17,23,24), and proteinase inhibitors (25)(26)(27)(28) have been reported to be present, but no positive correlation was found between the disease activity of the patient and the levels of enzyme and inhibitor present in those studies.…”

Section: Discussionmentioning

confidence: 94%

Metalloproteinases and collagenase inhibitors in rheumatoid synovial fluid

Cawston¹,

Mercer²,

Silva³

et al. 1984

Arthritis & Rheumatism

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The levels of metalloproteinases and metalloproteinase inhibitors were measured in rheumatoid synovial fluid. Reliable estimates of total enzyme and inhibitor levels in the synovial fluids were obtained only after hyaluronidase treatment and gel filtration. Three latent metalloproteinases were found which, after activation, degraded collagen, proteoglycan, and gelatin. These enzymes closely resembled the metalloproteinases secreted into connective tissue culture medium. In addition to aZ macroglobulin, an M, 30,000 collagenase inhibitor was detected which closely resembled the tissue inhibitor of metalloproteinase found in tissue culture medium.Rheumatoid arthritis is a disease in which a proliferating synovial pannus degrades cartilage matrix causing joint tissue damage. Little is known of the mechanism by which the cartilage collagen and proteoglycan are lost in vivo, although a number of proteolytic enzymes present in the tissues are capable of digesting these substrates (1). Much of our knowledge of the degradative enzymes secreted by the synovium has come from in vitro tissue and cell culture techniques.Collagenase is likely to be an important enzyme involved in these processes. This metalloproteinase cleaves all 3 cr chains of the triple helical collagen molecule at one point to give characteristic threefourth and one-fourth products. The enzyme is often tis and Rheumatism Council.form August 22, 1983. secreted in a latent form and collagenase activity often cannot be detected in the culture medium of many connective tissues unless the medium is first treated with trypsin (2,3), chaotrophic agents (4-6), or mercurials (7-9). A number of inhibitors of collagenase have been described (10). In addition lo cr2 macroglobulin and p, anticollagenase, a specific collagenase inhibitor has been detected and purified from culture medium (1 1). This inhibitor is thought to play a vital role in the extracellular control of collagenase activity. We have been interested in discovering to what extent these in vitro tissue culture results reflect the situation in vivo, and have therefore examined synovial fluid from rheumatoid joints. It is likely that if cartilage erobion is taking place, the level of either collagenase or inhibitor proteins would change and give an indication of the disease activity. Previous studies (12-18) have shown that both active and latent collagenases are pregent in some rheumatoid synovial fluid. However, no cprrelation was found between the amount of enzyme detected and the disease activity, and the amounts of collagenase inhibitors were not measured in these studies.In this report we have assayed for metalloproteinases and mctalloproteinase inhibitors in rheumatoid synovial fluids taken from patients with active disease. MATERIALS AND METHODSSynovial fluid, aspirated as part of a therapeutic procedure from knee joints of patients with rheumatoid arthritis, was put into sterile plastic containers and centrifuged at 10,OoOg for 20 minutes at 4°C. The cell-free supernatant synovial fluid was s...

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A neutral protease in rheumatoid synovial fluid capable of attacking the telopeptide regions of polymeric collagen fibrils

Cited by 48 publications

References 17 publications

A trypsin-like neutral protease on Ehrlich ascites cell surfaces: its role in the activation of tumour-cell zymogen of collagenase

A trypsin-like neutral protease on Ehrlich ascites cell surfaces: its role in the activation of tumour-cell zymogen of collagenase

Plasma Levels of Inhibitor-Bound Leukocytic Elastase in Rheumatoid Arthritis Patients

Metalloproteinases and collagenase inhibitors in rheumatoid synovial fluid

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