Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.37 (neutrophil elastase)
 4,078 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The binding of 125I-labelled transforming growth factor-beta 1 (TGF-beta 1) to human alpha 2-macroglobulin (alpha 2M) was studied by native PAGE and autoradiography. TGF-beta 1 bound preferentially to alpha 2M-methylamine and minimally, if at all, to native alpha 2M. Preparations of alpha 2M-proteinase complex were generated by incubating a standard concentration of alpha 2M (0.4 microM) with different concentrations of trypsin, chymotrypsin or neutrophil elastase (0.04-2.0 microM). The 125I-TGF-beta 1-binding activity depended on the initial ratio of active proteinase to alpha 2M, or r value, used to form the alpha 2M-proteinase complex. With all three proteinases, r values of 2 or greater yielded preparations with unchanged or decreased TGF-beta 1-binding activity relative to native alpha 2M. By contrast, r values near 1 yielded preparations with significantly increased TGF-beta 1-binding activity. The results of [3H]thymidine-incorporation studies performed in mouse keratinocytes were consistent with the 125I-TGF-beta-binding experiments. alpha 2M-trypsin and alpha 2M-chymotrypsin prepared at an r value of 1.0 counteracted the activity of TGF-beta 1, whereas the equivalent complexes prepared at an r value of 3.0 had no effect. As determined by SDS/PAGE, 125I-TGF-beta 1 binding to alpha 2M-methylamine was at least 80% non-covalent. Reaction of alpha 2M-methylamine with iodoacetamide or 5,5'-dithiobis-(2-nitrobenzoic acid) decreased the percentage of covalent binding but had no effect on total binding. Neuraminidase treatment had no effect on the binding of 125I-TGF-beta 1 to alpha 2M-methylamine. Cleavage of the 'bait regions' in alpha 2M-methylamine by prolonged treatment with trypsin also had no effect. These studies suggest that TGF-beta 1 binding to alpha 2M is enhanced by conformational change in the proteinase inhibitor resulting from reaction with proteinase or amine. If both proteinase-binding sites in a single alpha 2M molecule are occupied, TGF-beta 1-binding activity is decreased or perhaps eliminated.
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PMID:Binding of transforming growth factor-beta 1 to methylamine-modified alpha 2-macroglobulin and to binary and ternary alpha 2-macroglobulin-proteinase complexes. 137 Oct 50

Dextran derivatives were obtained by controlled successive substitutions of carboxymethyl, carbomethyl-benzylamide and carboxymethyl-benzylamide sulfonate groups on glucose residues. Among these derivatives, RGT11 was selected since it mimicked some properties of heparin or heparan sulfate to stabilise and protect heparin binding growth factors such as FGFs and TGF-beta. Furthermore RGT11 inhibited plasmine and leukocyte elastase. In previous works, we have explained the healing effects of RGT obtained in skin or bone repair models by these protecting and inhibiting properties. We now present the results obtained after a single injection of RGT11 in a regenerating crushed extensor digitorum longus (EDL) muscle. After 8 days, RGT11 injected muscles contained 10 times the number of fibers than controlled injected muscles. Fibers were organized in bundles of normal size. Histological analysis indicated that regeneration was comparable to that observed after 3 weeks without RGT. Hence in vivo, RGT11 could act by protecting the heparin binding growth factors involved in the natural process of muscle regeneration and therefore favour their actions. This family of polymers should offer a new pharmaceutical potential for treating muscle atrophy and destruction and is worth studying further.
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PMID:[Acceleration of the regeneration of skeletal muscles in adult rats by dextran derivatives]. 754 28

The proinflammatory cytokine interleukin-6 (IL-6) and its potential opponent, transforming growth factor-beta (TGF-beta 1), have been discussed as being involved in the regulation of inflammatory processes following trauma and infections. The aim of this study was to investigate the effect of these cytokines on the regulation of neutrophil degranulation. The posttraumatic time courses of the plasma concentrations of IL-6, and the elastase-alpha 1-proteinase-inhibitor complex as marker of degranulation in patients undergoing severe trauma were found to be highly correlated, whereas TGF-beta 1 levels were determined to be not significantly altered. The close temporal correlation of IL-6 and elastase levels could be confirmed by investigation of exudates derived from the surgical area. To prove these in vivo findings, the effect of IL-6 and TGF-beta 1 on the degranulation of isolated neutrophils of healthy donors was investigated in vitro. Pathological high IL-6 concentrations were found to be capable of inducing a significant release of lysosomal elastase in a concentration-dependent manner, whereas the degranulation was unaffected by TGF-beta 1. In conclusion, these data suggest an involvement of IL-6 in the regulation of neutrophil degranulation under pathological conditions. However, TGF-beta 1 seems to have no direct regulatory effects besides its described chemotactic function on neutrophils.
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PMID:Effects of interleukin-6 (IL-6) and transforming growth factor-beta (TGF-beta) on neutrophil elastase release. 770 89

Monolayer cultures of human epithelial and endothelial cells were used to study the association of latent transforming growth factor-beta 1 (TGF-beta 1) to extracellular matrices and its release and activation during matrix degradation. Human umbilical vein endothelial cells and embryonic lung fibroblasts produced relatively high levels of TGF-beta 1, its propeptide (beta 1-latency-associated protein), and latent TGF-beta-binding protein and incorporated latent TGF-beta 1 into their matrices as shown by immunoblotting. Amnion epithelial cells produced lower levels of these proteins. Confluent cultures of epithelial cells were exposed to matrix-degrading proteases and glycosidases. Mast cell chymase, leukocyte elastase, and plasmin efficiently released matrix-bound latent TGF-beta 1 complexes, while chondroitinase ABC and heparitinases were ineffective. The ability of the proteases to activate recombinant latent TGF-beta 1 was tested using growth inhibition assays and a novel sodium deoxycholate-polyacrylamide gel electrophoresis followed by immunoblotting. Sodium deoxycholate solubilized M(r) 25,000 TGF-beta 1 but did not dissociate high M(r) latent TGF-beta 1 complexes, allowing separation of these forms by polyacrylamide gel electrophoresis. Mast cell chymase and leukocyte elastase did not activate latent TGF-beta 1, suggesting that its release from matrix and activation are controlled by different mechanisms. The release of TGF-beta from the matrix by leukocyte and mast cell enzymes may contribute to the accumulation of connective tissue in inflammation.
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PMID:Human mast cell chymase and leukocyte elastase release latent transforming growth factor-beta 1 from the extracellular matrix of cultured human epithelial and endothelial cells. 787 40

The lysosomal cysteine proteinase cathepsin B is shown to be secreted by ten human colon carcinoma cell lines and to accumulate in culture media as a latent enzyme. The cell lines also secrete a physiological inhibitor of cathepsin B, cystatin C. A significant correlation was found between secretion of the latent enzyme and the inhibitor (r = 0.755, P < 0.01). The aim of the present study was to modulate the respective secretion of the two antagonists to test whether or not latency of cathepsin B was due to the concomitant secretion of the inhibitor. SW480 colon carcinoma cells were treated with the acidotropic agent ammonium chloride, phorbol 12-myristate 13-acetate, and the inflammatory cytokines TGF-beta, TNF-alpha, and IL-1 beta. Ammonium chloride significantly increased latent cathepsin B levels without affecting the constitutive secretion of cystatin C. Phorbol 12-myristate 13-acetate induced a 4- to 5-fold increase in secreted latent cathepsin B, but did not alter significantly the accumulation of cystatin C in media. The cytokines, TGF-beta, TNF-alpha, and IL-1 beta, had no major effect on the expression of these two antagonists. Latent cathepsin B released from human carcinoma cells could be efficiently activated by neutrophil elastase at neutral pH. It is concluded that latent cathepsin B is a true proenzyme rather than an enzyme-inhibitor complex. In addition, our data from neutrophil elastase activation experiments indicate that a proteolytic system for activation of the tumor cell-secreted latent enzyme may exist in vivo.
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PMID:Latency of cathepsin B secreted by human colon carcinoma cells is not linked to secretion of cystatin C and is relieved by neutrophil elastase. 820 57

Chronic lung disease of prematurity (CLD) is a common respiratory disorder of preterm infants. At autopsy, fibroblast proliferation, and components of the extracellular matrix, including collagen and fibronectin, are markedly increased in the lungs of infants who die from CLD. Examination of broncho-alveolar fluid suggests that the persistence of neutrophils is associated with the development of CLD. In our studies, the pro-inflammatory cytokines, interleukin-1 beta (IL-1 beta) and interleukin-6, (IL-6) and mediators which reflect neutrophil recruitment and activation, including soluble intercellular adhesion molecule, interleukin-8 (IL-8) and neutrophil elastase, were increased in lavage fluid obtained from infants who developed CLD when compared to infants who did not. Furthermore, semiquantitative reverse transcriptase-polymerase chain reaction of mRNA extracted from lavage cells suggested that luminal cells may be the source of IL-6 detected in lavage fluid but non-luminal cells may be the sources of IL-1 beta and IL-8. Fibrosis is thought to be mediated by the pro-fibrotic cytokines including transforming growth factor-beta1 (TGF-beta 1). Both active and total TGF-beta 1 were increased in lavage fluid from infants who developed CLD. Furthermore, both type I procollagen and TGF-beta were increased qualitatively in lung tissue obtained at autopsy from infants who died from respiratory failure. The increase in inflammatory mediators was maximal at 10 days of age. By contrast, the increase in TGF-beta 1 was maximal at 4 days of age. This suggests that the interaction between inflammation and fibrosis in CLD is complex, and that prenatal factors may be important in the pathogenesis of CLD.
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PMID:Cytokines in chronic lung disease of prematurity. 883 40

Increased leukocyte elastase activity in mice lacking secretory leukocyte protease inhibitor (SLPI) leads to impaired wound healing due to enhanced activity of TGFbeta and perhaps additional mechanisms. Proepithelin (PEPI), an epithelial growth factor, can be converted to epithelins (EPIs) in vivo by unknown mechanisms with unknown consequences. We found that PEPI and EPIs exert opposing activities. EPIs inhibit the growth of epithelial cells but induce them to secrete the neutrophil attractant IL-8, while PEPI blocks neutrophil activation by tumor necrosis factor, preventing release of oxidants and proteases. SLPI and PEPI form complexes, preventing elastase from converting PEPI to EPIs. Supplying PEPI corrects the wound-healing defect in SLPI null mice. Thus, SLPI/elastase act via PEPI/EPIs to operate a switch at the interface between innate immunity and wound healing.
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PMID:Conversion of proepithelin to epithelins: roles of SLPI and elastase in host defense and wound repair. 1252 12

Macrophages are host cells for the pathogenic parasite Leishmania major. Neutrophils die and are ingested by macrophages in the tissues. We investigated the role of macrophage interactions with inflammatory neutrophils in control of L. major infection. Coculture of dead exudate neutrophils exacerbated parasite growth in infected macrophages from susceptible BALB, but killed intracellular L. major in resistant B6 mice. Coinjection of dead neutrophils amplified L. major replication in vivo in BALB, but prevented parasite growth in B6 mice. Neutrophil depletion reduced parasite load in infected BALB, but exacerbated infection in B6 mice. Exacerbated growth of L. major required PGE(2) and TGF-beta production by macrophages, while parasite killing depended on neutrophil elastase and TNF-alpha production. These results indicate that macrophage interactions with dead neutrophils play a previously unrecognized role in host responses to L. major infection.
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PMID:Macrophage interactions with neutrophils regulate Leishmania major infection. 1503 61

Neutrophil elastase is a serine protease stored in the azurophilic granules of leukocytes. It has been implicated in the pathology of several lung diseases and is generally presumed to contribute to the tissue destruction and extracellular matrix damage associated with these conditions. To delineate the role of neutrophil elastase in pulmonary inflammation and fibrosis, neutrophil elastase-null mice were intratracheally instilled with bleomycin. In neutrophil elastase-null mice, biochemical and morphological characteristics of pulmonary fibrosis were attenuated for at least 60 days after bleomycin administration despite a typical response to bleomycin as evidenced by assessment of indices of DNA and cell damage. Neutrophil burden of bleomycin-treated wild-type and neutrophil elastase-null mice was comparable, and marked neutrophilic alveolitis was manifest in bleomycin-treated neutrophil elastase-null mice. An absence of immunostaining for active transforming growth factor (TGF)-beta in lung tissue from bleomycin-treated neutrophil elastase-null mice suggested a defect in TGF-beta activation, which was confirmed by biochemical assessment of TGF-beta levels in bronchoalveolar lavage fluid and lung tissue. These data point to novel and unexpected fibrogenic consequences of neutrophil elastase activity in the inflamed lung.
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PMID:Mice lacking neutrophil elastase are resistant to bleomycin-induced pulmonary fibrosis. 1720 Jan 83