Elastase activity, uninhibited by alpha 1-antitrypsin, in the periprosthetic connective matrix around loose total hip prostheses.

To clarify the proteolytic cascade in the loosening of total hip prostheses, the presence, tissue localization, and content of the serine proteinase, elastase, and its endogenous inhibitor, alpha 1-antitrypsin, were studied in periprosthetic tissues around 12 loose hip prostheses by immunohistochemistry, spectrophotometric enzyme assay, and immunoblot analysis, and the results were compared with those in control synovial tissue samples from eight knees. Increased numbers of elastase-immunoreactive cells and elevated elastase activity, inhibited by the addition of native alpha 1-antitrypsin, were observed both in the interface tissues between the bone and implants and in the pseudocapsular tissues from around loose hip prostheses. Elevated elastase activity, uninhibited by alpha 1-antitrypsin in situ and inhibited by the addition of native inhibitor, suggests a proteinase-inhibitor imbalance that contributes to the weakening of periprosthetic tissues and thus causes the loosening of hip prostheses.

Proteolytic enzymes as indicators of periodontal health in gingival crevicular fluid of patients with Sjögren's syndrome.

The present study characterizes the periodontal status of patients with Sjögren's syndrome (SS) and measures collagenase, elastase and gelatinase in gingival crevicular fluid (GCF) from these patients compared with adult individuals with periodontitis and healthy controls. The periodontal status was assessed by the Gingival Bleeding Index (GBI), the Visible Plaque Index (VPI), and pocket depth. Activity measurements were performed for collagenase with SDS-PAGE/laser densitometry, for elastase spectrophotometrically using a synthetic N-succinyl-Ala-Ala-Val p-nitroanilide peptide substrate, and for gelatinase with zymography. Seven of the 8 patients with SS and xerostomia showed a periodontium comparable to that seen in healthy controls. The GCF collagenase and elastase were significantly lower in patients with SS and in healthy controls than in patients with adult periodontitis. It was noteworthy that the one SS patient with periodontitis had high GCF collagenase and elastase activity. In all study groups multiple forms of gelatinases were present, indicating that they represent constitutively expressed proteinases involved in normal tissue remodeling processes. Our findings suggest that periodontal pockets/GCF form a micromilieu not affected by involvement of glandular tissue and, therefore, patients with SS show, clinically and biochemically, a periodontal status comparable to that seen in healthy controls.

Cathepsin G and alpha 1-antichymotrypsin in the local host reaction to loosening of total hip prostheses.

The tissue localization and content of the proteolytic enzyme cathepsin G and its inhibitor alpha 1-antichymotrypsin were studied in the local host reaction to loosening of total hip-replacement prostheses in eleven patients and were compared with those in samples of non-inflammatory tissue from the synovial capsule obtained during arthroscopies of the knee. Immunostaining demonstrated cellular localization of cathepsin G in 71 per cent of monocyte or macrophage-like cells and in 46 per cent of fibroblast-like cells in the samples of interface tissue between the bone and the loose acetabular component obtained at the time of the total hip replacements, and in 59 and 42 per cent, respectively, in the samples of pseudocapsular tissue obtained at the same time, whereas the synovial lining cells in the samples of non-inflammatory tissue from the synovial capsule revealed only a slight immunoreactivity to cathepsin G. Cathepsin-G activity was also measured with synthetic succinyl-alanine-alanine-proline-phenylalanine-paranitroanilide as a substrate, the degradation of which was monitored spectrophotometrically. In accordance with results from immunohistochemical studies, cathepsin-G activity was found in the samples of interface tissue (31.6 international units per liter) and the samples of pseudocapsular tissue (15.5 international units per liter) obtained during the total hip replacements, whereas the level of cathepsin-G was low in the samples of non-inflammatory synovial capsular tissue (2.5 international units per liter). Cathepsin-G activity in the samples of pseudosynovial fluid obtained at the time of the total hip replacements was low (2.4 international units per liter), although immunoblot analysis showed marked immunoreactive cathepsin G in the samples of pseudosynovial fluid. This low activity of cathepsin G might be explained by the presence of alpha 1-antichymotrypsin, which was detected by laser nephlometric immunoassay and immunoblot analysis. These results demonstrate increased concentration of cathepsin G locally in the tissues around loose total hip-replacement prostheses. Because cathepsin G is not only able to act on extracellular matrix components (such as gelatin, proteoglycan, elastin, and laminin) at a physiological pH but also is able to activate collagenase, gelatinase, and stromelysin proenzymes, to inactivate tissue inhibitor of metalloproteinases, and to modulate tumor necrosis factor-alpha, it may play an important role in the degradation of periprosthetic connective tissue and in the lysis of bone around the implant, thus contributing to the loosening of prostheses.(ABSTRACT TRUNCATED AT 250 WORDS)

Collagenase in Sjögren's syndrome.

OBJECTIVE: To study collagenase production in labial salivary glands in patients with Sjögren's syndrome (SS). METHODS: Collagenases were localised in labial salivary glands by immunohistochemistry. Collagenase activity against triple helical type I collagen monomers in stimulated saliva was measured using sodium dodecyl sulphate polyacrylamide gel electrophoresis and laser densitometry; tissue inhibitor metalloproteinase (TIMP) was measured by enzyme linked immunosorbent assay. RESULTS: Cells containing collagenase of matrix metalloproteinase (MMP)-1 type were more frequent and more intensely staining in SS than in healthy glands. Only SS saliva contained functional enzyme (11.7 (6.8) x 10(-6) IU/1). Cells containing MMP-8 type neutrophil collagenase were not found in situ, which was in accordance with sialochemical findings/doxycycline inhibition studies. TIMP was found in both SS and normal saliva. CONCLUSIONS: Fibroblast, but not neutrophil type, collagenase is synthesised, secreted, and subsequently activated, but is not inhibited by TIMP in labial salivary glands or saliva in SS. Collagenase may destroy glandular and salivary duct tissue and perturb factors influencing the morphogenetic extracellular matrix.

Elastase and alpha-1-proteinase inhibitor in gingival crevicular fluid and gingival tissue in adult and juvenile periodontitis.

The presence and localization of PMN/neutrophil elastase and its endogenous inhibitor alpha 1-proteinase inhibitor (alpha 1 PI) were studied immunohistochemically in gingival tissue specimens collected from 9 adult periodontitis (AP) patients during flap surgery after the initial phase of periodontal therapy, and from 6 healthy controls with clinically-healthy periodontium upon surgical extraction of impacted third molars. In order to evaluate how periodontal tissue destructive events are reflected in gingival crevicular fluid (GCF), GCF samples were collected from the AP patients before any periodontal treatment and prior to flap surgery, from 5 localized juvenile periodontitis (LJP) patients, and from the controls. Elastase activity in the GCF was measured with the SAAVNA-assay and the molecular forms and amount of alpha 1PI by Western- and dot-blotting. Immunohistochemical staining for PMN elastase was strongly positive in the connective tissue, but not in the epithelium, of the AP patients' gingival tissue specimens. In the healthy gingival tissue specimens only a few elastase-positive cells were present. Both in AP and in control gingival specimens, alpha 1PI was detected in the connective tissue and in the keratinized layer of the epithelium, however, its amount was markedly lower in the control specimens. Elevated levels of alpha 1PI and PMN elastase were detected in the GCF of all periodontitis patients when compared to controls.(ABSTRACT TRUNCATED AT 250 WORDS)