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

Current approaches to the detection of patients at risk for preterm delivery (PTD) have focused on the diagnosis of preterm labor. However, these approaches are complicated by treatment biases and our inability to convincingly differentiate preterm labor from Braxton-Hicks contractions. Moreover, preterm labor with intact membranes accounts for only one-half of all spontaneous PTDs since uterine contractions follow preterm premature rupture of the membranes (PROM) in an additional 50% of cases. Clinical dogma holds that the prevention of PTD requires the early detection of at risk patients. However, clinical indicators of PTD risk including cervical change, uterine contractions, vaginal bleeding, maternal demographic featuers and obstetrical history have poor sensitivity and/or specificity. Fortunately, an improved understanding of the association between preterm parturition and cervical, chorionic and decidual extracellular matrix degradation has led to a number of promising new biochemical indices of the proteolytic processes leading to PTD. These include measurement of serum collagenase activity and assessment of cervico-vaginal granulocyte elastase and oncofetal fibronectin levels. It remains to be seen, however, whether an improved detection of patients at risk will lead to a reduction in the occurrence of PTD.
 ...
PMID:New approaches to the prediction of preterm delivery. 800 70

The potential role of neutrophil elastase in causing lung damage and exacerbating the inflammatory response in cystic fibrosis (CF) has received considerable attention. Although another potent neutrophil-derived enzyme, collagenase, is implicated in tissue destruction in several interstitial lung disorders, there has been no reference to this enzyme in CF. The objective of this study was to determine whether neutrophil collagenase is present in active form in CF sputum and, if so, whether it is related to disease severity. High levels of active collagenase were detected in sputum from patients with CF, and the majority of the enzyme present was of neutrophil origin. In a group of 16 patients with CF, negative relations between sputum collagenase activity and Shwachman score (r = -0.55, p < 0.05) and FEV1 (r = -0.59, p < 0.02) were noted, indicating an association between high collagenase activity and severity of disease. A positive correlation was observed between sputum collagenase and elastase activity (r = 0.62, p < 0.05). These results suggest that both neutrophil elastase and collagenase may play a significant role in lung destruction in CF.
 ...
PMID:Neutrophil collagenase in sputum from patients with cystic fibrosis. 808 57

Matrix metalloproteinases (MMPs) and neutrophil elastase (NE) may each contribute to fibrillar collagen degradation in various disease states. Little, however, is known about the activation and localization of MMP in the heart. Accordingly, we extracted MMP and examined mechanisms of proMMP activation in whole tissue extracts of the adult rat myocardium. Incubation of extracts with serine proteases (i.e., trypsin or neutrophil elastase) at 37 degrees C resulted in a time-dependent activation of proMMPs. Based on immunoblot and measurements of MMP activity by zymography, the molecular weight of active MMP was deduced to be 52 kDa. The second-order rate constant for activation of proMMP by serine protease was 5.5 +/- 0.2 x 10(5) M-1min-1 and for oxidized glutathione (GSSG) 1.5 +/- 0.1 M-1min-1. Incubation of the extract with both serine protease and GSSG increased the rate of activation 30-fold. Based on reverse zymographic analysis of collagenase inhibition, tissue inhibitors of metalloproteinases were identified. Indirect immunofluorescence localized proMMPs/MMPs to the endothelium and subendothelial space of the endocardium and throughout the interstitial space found between groups of muscle fibers. These results suggest that the mechanism of activation of MMPs by either a serine protease and by oxidizing, thiol-modifying reagents are mechanistically different and the presence of either a serine protease or GSSG synergistically increase the rate of activation of proMMPs. Our results also suggest that MMPs may be regulated by its own endogenous inhibitors. The contribution of this proteolytic enzyme to tissue remodeling and wound healing responses that occur in various diseases states remains to be established.
 ...
PMID:Myocardial matrix metalloproteinase(s): localization and activation. 810 89

The concentration of doxycycline required to inhibit 50% (50% inhibitory concentration for serpinase activity) of alpha-1-antitrypsin degradation by purified neutrophil collagenase was found to be approximately 20 microM, a value similar to the 50% inhibitory concentration of doxycycline required to inhibit collagen degradation by neutrophil collagenase. Doxycycline also efficiently inhibited phorbol myristate acetate-triggered neutrophil-mediated degradation of alpha-1-antitrypsin. This suggests that doxycycline can protect alpha-1-antitrypsin from collagenase and gelatinase in the presence of other proteases and biologically active molecules that are released by triggered neutrophils. The protection of a body's alpha-1-antitrypsin shield from serpinolytic activity of collagenase and matrix metallproteinases can result in inhibition of serine proteases such as neutrophil elastase. Tetracyclines may thus protect matrix constituents from a wider spectrum of neutral proteases than previously recognized, not just from the matrix metalloproteinases collagenase and gelatinase.
 ...
PMID:Doxycycline in the protection of serum alpha-1-antitrypsin from human neutrophil collagenase and gelatinase. 838 19

Elastinolytic activity of medullasin was investigated precisely and compared with that of human leukocyte elastase, because the structure of medullasin is quite similar to that of human neutrophil elastase, which was reported to have elastinolytic activity. When elastinolytic activity of medullasin and human leukocyte elastase was determined by employing unstained elastin fibers and measuring the increase in 280-nm absorbance of the supernatant, elastinolytic activity amounting to several percent of that of porcine pancreas elastase was apparently observed. However, the susceptibility of elastin preparations to these proteases was proportional to their hydroxyproline content. Both medullasin and human leukocyte elastase digested collagen fibers obtained from bovine Achilles tendon to the same extent as collagenase from Clostridium histolyticum. When elastinolytic activity was determined by employing elastin fibers stained with orcein, both proteases showed negligible elastinolytic activity. The activity remained negligible even when the pH or ionic strength of the reaction mixture was altered. These results indicate that medullasin and human leukocyte elastase are essentially devoid of elastinolytic activity, and that apparent elastinolytic activity observed when unstained elastin fibers were employed as the substrate is due to the digestion of collagen fibers mingled with elastin preparations.
 ...
PMID:Both medullasin and human leukocyte elastase are essentially devoid of elastinolytic activity. 840 64

Interstitial collagenases, members of the matrix metalloproteinase family, are key initiators of collagen destruction during various disorders such as rheumatoid arthritis. Recently interstitial collagenases were found to efficiently degrade an additional non-collagenous substrate, the serum alpha-1-antitrypsin (AAT also called alpha-1-proteinase inhibitor or serpin). Serpins are major endogenous inhibitors of serine proteinases, particularly neutrophil elastase. Of relevance to neutrophil-mediated collagen degradation, the tetracycline family of antibiotics are now known to inhibit inhibit mammalian collagenases by a mechanism unrelated to their antimicrobial activity. This study identifies an additional mechanism by which tetracyclines may retard tissue breakdown during inflammatory diseases. Doxycycline, added to the reaction mixture as in concentrations as low as 10 microM, which correspond to levels of the drug readily achieved in vivo, produced detectable inhibition of serpinase activity of neutrophil collagenase, although levels of 50-100 microM or greater were required to reduce AAT degradation more than 75%. The concentration of doxycycline to inhibit 50% (IC50 of serpinase activity) of AAT degradation by neutrophil collagenase was found to approximate 20 microM, a value similar to the IC50 for doxycycline required to inhibit collagen degradation by neutrophil collagenase. Doxycycline was also found to inhibit at cell level neutrophil-mediated degradation of AAT. The protection of bodies' AAT-shield from serpinolytic activity of collagenase would result in inhibition of serine proteinases such as neutrophil elastase. Tetracyclines may thus protect matrix constituents from a wider spectrum of neutral proteases than previously recognized, not just from the matrix metalloproteinases collagenase and gelatinase.
 ...
PMID:Doxycycline protects serum alpha-1-antitrypsin from human neutrophil collagenase. 845 33

We present the first direct biochemical evidence for the turnover of intact type VI collagen microfibrils. Matrix-degrading enzymes of the serine proteinase class, including rat mast cell chymases I and II, human mast cell tryptase, neutrophil elastase, cathepsin G and trypsin, were able to catabolize intact type VI collagen microfibrils isolated from foetal bovine skin and metabolically labelled intact type VI collagen immunoprecipitated from fibroblast culture medium. By contrast, intact type VI collagen was not degraded by the human matrix metalloproteinases, MMP-1, MMP-2, MMP-3 and MMP-9. These data have important implications for the stability of type VI collagen in connective tissues and highlight the potential role of serine proteinases both in normal type VI collagen turnover and in inflammatory conditions characterized by matrix degradation.
 ...
PMID:Catabolism of intact type VI collagen microfibrils: susceptibility to degradation by serine proteinases. 846

Clinical approaches to the diagnosis of PTL and the prediction of PTD are complicated by the absence of a gold standard for the pathogenic process leading to PTD. There is also substantial overlap between the signs and symptoms of PTL and impending PTD, and the normal processes of pregnancies destined to remain uncomplicated (e.g., our inability to convincingly differentiate PTL from Braxton-Hicks contractions). Our emphasis on the diagnosis of PTL rather than the pathogenic process preceding PTD also results in failure to detect the 50% of spontaneous PTDs in which uterine contractions follow PPROM. Thus, clinical predictors of incipient PTD including cervical change, uterine contractions, vaginal bleeding, risk scoring schemes, and fetal breathing activity, either have poor sensitivity or specificity, or are accurate only at late stages in the pathogenic process. The most promising approaches to the detection of impending PTD are laboratory indices of the putative pathogenic processes including: maternal serum or plasma CRH, salivary E3, serum collagenase and cervicovaginal cytokines, granulocyte elastase, and FFN levels. However, even if these indices prove sensitive, specific, and early predictors of PTD, they will be useful only if more appropriate therapies are found to treat patients. The latter will depend on addressing the primary causes of chorionic-decidual cell activation (e.g., infection, stress, utero-placental ischemia, hemorrhage, endocrinopathies).
 ...
PMID:The diagnosis of preterm labor and the prediction of preterm delivery. 861 65

Alpha-1 proteinase inhibitor (A1-Pi) is the main serine proteinase inhibitor found in human plasma and is a potent elastase inhibitor in various tissues, including lung. A1-Pi is expressed and induced in liver during inflammatory responses but can also be produced by epithelial cells. Since hepatocyte A1-Pi production is stimulated by interleukin-6 (IL-6) and other gp130-cytokines, such as leukemia inhibitory factor (LIF) and oncostatin M (OM), we investigated the role of these cytokines in regulating A1-Pi in lung epithelial cells. We show that OM, a monocyte and T cell product, can specifically and potently induce A1-Pi production in lung-derived A549 alveolar (epithelial) cells, as well as in liver-derived HepG2 cells. Both A1-Pi protein (as detected by ELISA and Western blots) and mRNA levels were enhanced 20-fold to 30-fold in A549 cells. OM was also able to stimulate the expression of tissue inhibitor of metalloproteinase-1 in these cells. Interestingly, other members of the IL-6 family (IL-6 and LIF) had little or no effect on A549 cells, and proinflammatory cytokines, such as IL-1 beta and tumor necrosis factor-alpha (TNF-alpha) also had no stimulatory effect on A1-Pi synthesis in A549 cells. Costimulation with IL-1 beta resulted in a decrease in A1-Pi production from OM-stimulated A549 cells. However, IL-6 production was synergistically enhanced. OM was also able to stimulate A1-Pi production from a bronchial epithelial primary cell line, whereas an intestinal epithelial cell line HT29 responded to IL-6 but not OM. These results suggest that lung levels A1-Pi could be derived not only from liver and inflammatory cells but also from epithelial cells, which can be upregulated on stimulation by OM. This may have implications for regulation of local activity of human neutrophil elastase (HNE) in such diseases as emphysema and cystic fibrosis.
 ...
PMID:Oncostatin M, but not interleukin-6 or leukemia inhibitory factor, stimulates expression of alpha1-proteinase inhibitor in A549 human alveolar epithelial cells. 919 1

The aim of this study was to investigate the extracellular degrading proteolytic cascade proteins referred to as matrix metalloproteinase-1 (MMP-1), MMP-2, MMP-9, membrane-type matrix metalloproteinase-1 (MT1-MMP), tissue inhibitors of matrix metalloproteinase-1 (TIMP-1), TIMP-2, neutrophil elastase, and alpha1-antitrypsin in human pulmonary emphysema. Localization of MMP-1, MMP-2, MMP-8, MMP-9, MT1-MMP, TIMP-1, and TIMP-2 was verified by immunohistochemical analysis. The results of our study indicated that the immunoreactivity of MMP-1, MMP-8, MMP-9, and TIMP-1 was absent, whereas MT1-MMP and MMP-2 were mainly observed in pneumocytes, fibroblasts, and alveolar macrophages. Although MT1-MMP and MMP-2 were observed both in emphysematous and normal lung tissue, these immunoreactivities were intense in the emphysematous samples. The presence of MMP-1, MMP-2, MMP-9, TIMP-1, and TIMP-2 was confirmed at mRNA level by reverse transcription-PCR analysis and enzyme immunoassay (EIA). However, the only statistical difference that was observed was in MMP-2 and MMP-9 (MMP-2: emphysematous samples, 19.1+/-2.1 versus control samples, 5.2+/-0.60 microg/g protein, p < 0.05; MMP-9: emphysematous samples, 18.4+/-5.6 versus control samples, 8.1+/-2.7 microg/g protein, p < 0.05). Results of the neutrophil elastase as analyzed by EIA, and alpha1-antitrypsin levels as detected by laser nephelometric immunoassay, indicated no statistical difference between the emphysematous and control groups. In addition to the presence of mRNA levels, the level of MT1-MMP according to immunoblot analysis increased in the emphysematous samples. Gelatin zymographic analysis confirmed the presence of both pro and active forms of MMP-2, and the increased ratio of the active form of MMP-2 in emphysematous samples (25.9%+/-2.0% versus 11.2%+/-3.3%, p < 0.05), indicated in situ activation of MMP-2 by MT1-MMP. Elastin zymographic analysis showed elastolytic activity by MMP-2 and MMP-9 but not the reported band of macrophage metalloelastase (MMP-12). The data suggest that the MT1-MMP/MMP-2/TIMP-2 system plays a significant role in the MMP-mediated extracellular matrix degradation and tissue remodeling of emphysematous lungs, and thus may contribute to the weakening of lung parenchyma and lead to the formation of emphysema.
 ...
PMID:Matrix metalloproteinase-mediated extracellular matrix protein degradation in human pulmonary emphysema. 975 52


<< Previous 1 2 3 4 5 6 7 8 9 Next >>