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Query: EC:3.4.21.7 (
plasmin
)
9,023
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
We studied the temporal expression of interstitial collagenase, stromelysin-1 and -2, and urokinase plasminogen activator (uPA) mRNAs by in situ hybridization in eight patients with dermatitis herpetiformis. To induce blisters, 50% potassium iodide patch tests were performed, and serial biopsy specimens were taken at 4, 12, and 24 h. Additional samples were taken from occasional spontaneous blisters. Components of the basement membrane, laminin-5, laminin-1, and type VII collagen, were examined immunohistochemically in relation to matrix metalloproteinase expression. At 12 h, when no blisters were seen, uPA mRNA was present in basal keratinocytes in five of eight samples, whereas interstitial collagenase and stromelysin-1 mRNA were not detected. At this time, immunohistochemistry failed to show changes in the basement membrane. At 24 h, uPA, collagenase, and stromelysin-1 mRNAs were present in basal keratinocytes, suggesting an activation of latent forms of the two latter enzymes by the uPA-
plasmin
pathway. Signal for stromelysin-2 was not detected. Furthermore, disruptions of laminin-1 and type VII collagen were evident. The data suggest that stromelysin-1 and interstitial collagenase may contribute to the degradation of basement membrane in dermatitis herpetiformis. Intracellular staining for laminin-5 co-localized with collagenase mRNA in basal keratinocytes. Because laminin-5 is essential for adhesion of keratinocytes to basement membrane and for establishment of focal adhesions on migrating cells, its production may reflect a regenerative response after the destruction of basement membrane components.
J Invest
Dermatol
1997 Jan
PMID:Urokinase plasminogen activator is expressed by basal keratinocytes before interstitial collagenase, stromelysin-1, and laminin-5 in experimentally induced dermatitis herpetiformis lesions. 898 Feb 78
Because wounding the epidermis increases proteolytic activity and because disorders associated with barrier dysfunction have elevated protease activity, we studied the effect of protease inhibitors on the time course of barrier recovery and on the development of epidermal hyperplasia induced by repeated injury. After injuries to the epidermis produced by tape stripping, acetone treatment, or detergent (SDS) treatment that disrupt the barrier, a single application of 5% tranexamic acid [4-(aminomethyl)cyclohexane carboxylic acid, t-AMCHA], a well known anti-
plasmin
reagent, accelerated barrier recovery in both hairless mouse and human skin. In contrast, neither aminocaproic acid nor aminobutyric acid, inactive analogs of t-AMCHA, affected the time course of barrier recovery. Several trypsin-like serine protease inhibitors, e.g., leupeptin, TLCK, and PMSF, also accelerated barrier repair. In contrast other types of protease inhibitors, e.g., EDTA, pepstatin, N-ethylmaleimide, chymostatin, and TPCK, did not accelerate barrier recovery. We next evaluated the effects of daily topical application of t-AMCHA on epidermal hyperplasia, induced by repeated tape stripping or acetone treatment for 7 d. The degree of hyperplasia, quantified by the measurement of epidermal thickness, was reduced in both models by repeated applications of t-AMCHA. Finally, proteolytic activity in both human and mouse epidermis increased 1-2 h after epidermal injuries that disrupt the barrier. These results demonstrate that the inhibition of
plasmin
, a serine protease, accelerates barrier recovery and inhibits the epidermal hyperplasia induced by repeated barrier disruption, perhaps by decreasing the extent of attendant epidermal injury.
J Invest
Dermatol
1997 Jul
PMID:trans-4-(Aminomethyl)cyclohexane carboxylic acid (T-AMCHA), an anti-fibrinolytic agent, accelerates barrier recovery and prevents the epidermal hyperplasia induced by epidermal injury in hairless mice and humans. 920 60
We previously found that the binding of pemphigus IgG to desmogleins caused marked activation of phospholipase C, a transient increase in inositol 1,4,5-trisphosphate production, and a concomitant increase in the intracellular calcium concentration in DJM-1 cells, a squamous cell carcinoma line. The binding of pemphigus IgG to cell membranes increased the activity of urokinase plasminogen activator in culture medium and induced subsequent cell-cell detachment in DJM-1 cells. Because urokinase plasminogen activator activates the conversion of plasminogen to
plasmin
by binding to urokinase plasminogen activator receptor evading inhibitors in serum, it is likely that
plasmin
is generated only in microenvironments adjacent to urokinase plasminogen activator receptor on the cell surface. It is not known whether pemphigus IgG causes acantholysis by inducing urokinase plasminogen activator receptor expression on the cell surface and secreting urokinase plasminogen activator in inhibitor-rich environments. We examined the effects of pemphigus IgG on urokinase plasminogen activator receptor expression in DJM-1 cells and normal keratinocytes by immunoblot analysis and immunofluorescence microscopy using antibodies to urokinase plasminogen activator receptor. IgG were obtained from serum samples from eight patients with bullous pemphigoid, five patients with pemphigus vulgaris, seven patients with pemphigus foliaceus, and eight normal subjects. Pemphigus vulgaris and pemphigus foliaceus IgG significantly increased the urokinase plasminogen activator receptor expression on the surface of DJM-1 cells and normal keratinocytes after 3- and 7-d incubation compared with normal IgG. These results suggest that enhanced urokinase plasminogen activator activity and urokinase plasminogen activator receptor expression activates
plasmin
in the limited cell surface of pemphigus IgG-bound keratinocytes and may contribute to the pathogenesis of differential acantholysis in pemphigus vulgaris and pemphigus foliaceus.
J Invest
Dermatol
1997 Nov
PMID:Pemphigus IgG induces expression of urokinase plasminogen activator receptor on the cell surface of cultured keratinocytes. 934 94
Scleroderma fibroblasts exhibit numerous phenotypic differences when compared with healthy skin fibroblasts. Some of these differences, in particular overexpression of collagen type I and other extracellular matrix proteins, parallel the effect of transforming growth factor-beta (TGF-beta) on dermal fibroblasts, suggesting that the scleroderma fibroblast phenotype may result from activation of autocrine TGF-beta signaling. To test this hypothesis we examined the role of TGF-beta Type I and Type II receptors in regulating collagen type I transcription. We have shown that overexpression of either Type I or Type II receptors significantly (3-4-fold) increases alpha2 (I) collagen promoter activity in transient transfection assays in dermal fibroblasts. Addition of anti-TGF-beta antibody abolished, whereas addition of
plasmin
enhanced, the stimulatory effect of receptor overexpression on collagen promoter activity, suggesting that this effect depends on autocrine TGF-beta. Moreover, these cotransfection experiments indicated that expression levels of TGF-beta receptors is a limiting factor in the autocrine regulation of collagen type I transcription by TGF-beta. Comparison of the TGF-beta receptor Type I and Type II mRA expression levels in scleroderma and normal fibroblasts have indicated elevated expression (2-fold) of both receptor types in scleroderma cells, which correlated with increased binding of TGF-beta. Significantly, elevated TGF-beta receptor levels correlated with elevated alpha2 (I) collagen mRNA levels. These results suggest that the elevated production of collagen type I by scleroderma fibroblasts results from overexpression of TGF-beta receptors.
J Invest
Dermatol
1998 Jan
PMID:Increased expression of TGF-beta receptors by scleroderma fibroblasts: evidence for contribution of autocrine TGF-beta signaling to scleroderma phenotype. 942 86
Proteolytic enzymes have been used for wound debridement for many years. The two enzymes most widely used in Europe are
fibrinolysin
/desoxyribonuclease and collagenase. Despite their frequent use, very few placebo-controlled studies comparing the enzymes with vehiculum only, or with each other, are available. In a specially developed necrotic ulcer animal model, combined with a computer image analysis technique to measure necrotic and total wound surface areas quantitatively, we assessed the wound-cleansing properties of
fibrinolysin
/DNase oleogel, collagenase ointment, saline-soaked gauze control treatment, and new galenic formulations of collagenase, including placebos. The average relative area of necrotic tissue present in the wound after 1 week was 31% for collagenase ointment and 56% for
fibrinolysin
/DNAse oleogel (P = 0.0037). Collagenase gel was significantly (P = 0.0007) better in removing necrosis than placebo (gel only). Fibrinolysin/DNAse was not significantly more effective than the three placebo or control treatments (placebo film, placebo gel, saline-soaked gauzes). We conclude that collagenase is a suitable enzyme for wound debridement, but we were not able to detect clinical efficacy of
fibrinolysin
/DNAse in this model.
Arch
Dermatol
Res 1998 Mar
PMID:Quantitative and objective evaluation of wound debriding properties of collagenase and fibrinolysin/desoxyribonuclease in a necrotic ulcer animal model. 955 91
Six patients with documented systemic mast cell disease were enrolled in a 1-year, phase I study to determine the possible benefits of interferon alpha-2b (IFN-alpha). IFN-alpha therapy was begun at a dosage of 0.5 million units/day (MU/day) by subcutaneous injection and increased, as tolerated, to 3.0 MU/day. Subsequent dose modifications were made based on clinical tolerance and response. No immediate, adverse reactions to IFN-alpha occurred. Several patients showed symptomatic improvement. In two patients ascites resolved and did not recur. Two other patients reported improved energy levels and had decreased size of retroperitoneal, measenteric and retrocrural nodes. One patient failed to benefit and died shortly after completing 12 months of therapy. Bone marrow mastocytosis decreased by 5% to 10% after 12 months of therapy with IFN-alpha. Although five of the six patients had a decrease in the urinary excretion of 1-methyl-4-imidazole acetic acid,
serum tryptase
values did not appreciably change in any patient. Side-effects from IFN-alpha included hypothyroidism, thrombocytopenia and depression. It is concluded that although treatment with IFN-alpha was associated with a decline in bone marrow mastocytosis and reduced excretion of histamine metabolites, prolonged therapy may be needed and dose-limiting side-effects are frequent.
Br J
Dermatol
1998 Mar
PMID:Response of severe systemic mastocytosis to interferon alpha. 958 Aug 6
Tripe palms are thickened, moss-like or velvety textured exaggerations of the normal dermatoglyphics. The disease belongs to the spectrum of papulosquamous paraneoplastic syndromes. Although suspected, the role of transforming growth factor-alpha (TGF-alpha) has not been clearly established. A 54-year-old man with systemic mastocytosis presented with thickening and darkening of the palms and soles. We performed skin biopsies for light microscopy (including toluidine blue), in situ hybridization and double labelling, and determination of
serum tryptase
, histamine and TGF-alpha levels. Toluidine blue stained the mast cells that had massively infiltrated the dermis. Tripe palm samples showed extensive hyperkeratosis. The TGF-alpha probe reacted strongly with the mast cells that also reacted with the antitryptase monoclonal antibody. Elevated tryptase, histamine and TGF-alpha levels prior to interferon-alfa administration decreased under treatment. The demonstration of TGF-alpha in infiltrating mast cells, the clinical regression of tripe palms and the lowering of the serum level and the mast cell molecular signal of the cytokine when systemic mastocytosis was controlled by interferon-alfa, suggest a key role for TGF-alpha in this cutaneous paraneoplastic syndrome.
Br J
Dermatol
1998 Apr
PMID:Tripe palms associated with systemic mastocytosis: the role of transforming growth factor-alpha and efficacy of interferon-alfa. 964 Mar 84
Plasminogen, the pro-enzyme of
plasmin
, aids various processes essential for normal, acute wound healing, such as fibrinolysis and cell migration. We have investigated if plasminogen is available to perform these functions in chronic wounds such as venous leg ulcers. We report that plasminogen is degraded by fluid from venous leg ulcers to a number of fragments, including kringle domains 1-3, an angiostatin-related protein. The enzyme responsible was inhibited by the serine protease inhibitor phenyl-methylsulfonyl fluoride, but was not inhibited by alpha1-anti-trypsin, an inhibitor of neutrophil elastase, by alpha2-anti-
plasmin
, an inhibitor of
plasmin
, or by the matrix metalloprotease inhibitor 1,10 phenanthroline. Plasminogen degraded by wound fluid was a weaker substrate than intact plasminogen for
plasmin
generation by the keratinocyte cell line HaCaT. These results suggest that serine protease activity in leg ulcer fluid degrades plasminogen and support the hypothesis that keratinocyte migration may be impaired in leg ulcers because of a reduced availability of intact plasminogen for
plasmin
generation.
J Invest
Dermatol
1998 Dec
PMID:Wound fluid from venous leg ulcers degrades plasminogen and reduces plasmin generation by keratinocytes. 985 30
Serum tryptase was measured with the B12 and G5 antibody-based immunoassays in 25 adult patients with mastocytosis and in 18 controls. Twelve patients had uncomplicated cutaneous mastocytosis (urticaria pigmentosa) and 13 had urticaria pigmentosa with systemic symptoms. Tryptase levels were compared with histamine turnover estimated as urinary excretion of the main histamine metabolite tele-methylimidazoleacetic acid. Elevated B12 tryptase levels (> 20 microg/L) were found in most mastocytosis patients, including five of eight patients with only cutaneous manifestations who had a low urinary histamine metabolite excretion. This indicated a higher sensitivity for diagnosing mild mastocytosis on the basis of levels of
serum tryptase
as opposed to urinary methylimidazoleacetic acid. However, the serum B12 tryptase assay could not differentiate between urticaria pigmentosa patients with and without systemic disease: the measurement of histamine metabolite excretion probably reflects the mast cell burden more accurately. Serum G5 tryptase levels were generally low in both controls and mastocytosis patients.
Br J
Dermatol
1998 Nov
PMID:Serum tryptase measured with B12 and G5 antibody-based immunoassays in mastocytosis patients and its relation to histamine turnover. 989 55
Keratinocytes synthesize and secrete urokinase-type plasminogen activator, which binds to its specific receptor on keratinocytes. When bound to urokinase-type plasminogen activator receptor, urokinase-type plasminogen activator proteolytically converts surface bound plasminogen to
plasmin
, which in turn cleaves many extracellular components leading to pericellular proteolysis. The activation of the urokinase system has been observed during re-epithelialization of skin wounds and in lesions of the autoimmune blistering skin disease pemphigus. As pemphigus is photoinducible, we investigated the effect of ultraviolet B on urokinase-type plasminogen activator and urokinase-type plasminogen activator receptor expression in the epidermal keratinocyte cell line A431. Ultraviolet B increased cellular and secreted urokinase-type plasminogen activator protein (enzyme-linked immunosorbent assay) and urokinase-type plasminogen activator receptor cell surface expression (flow cytometry) 24 h postirradiation. Northern blot analysis indicated that ultraviolet B increased urokinase-type plasminogen activator receptor mRNA. Compared with a more rapid mRNA induction by epidermal growth factor (maximal after 4 h) the ultraviolet B response was maximal after 24 h and prolonged up to 36 h. The mRNA induction was not dependent on protein synthesis as judged by cycloheximide incubation. Ultraviolet B did not influence urokinase-type plasminogen activator receptor mRNA stability (actinomycin D incubation). A transiently transfected chloramphenicol acetyltransferase-reporter construct containing a -398/+51 urokinase-type plasminogen activator receptor promoter fragment was activated when cells were exposed to ultraviolet B. This induction was almost completely abolished by mutating a -182/-176 AP-1 binding sequence. Ultraviolet B increased the binding capacity at this AP-1 motif in electrophoretic mobility shift assays. These data identify a distinct transcriptional mechanism by which ultraviolet B induces urokinase-type plasminogen activator receptor. The epidermal induction of components of the proteolytic urokinase system by ultraviolet B may help explain the photoinducibility of pemphigus lesions.
J Invest
Dermatol
1999 Jul
PMID:UVB increases urokinase-type plasminogen activator receptor (uPAR) expression. 1041 21
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