Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0034067 (emphysema)
 11,506 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Proteolysis of elastic fibers is central to the development of emphysema, and a simple, noninvasive assay of elastin degradation would be useful in diagnosis and in therapeutic monitoring. We have adapted an indirect enzyme-linked immunosorbent assay (ELISA) to determine plasma, urine, and bronchoalveolar lavage fluid (BALF) elastin peptide concentrations in nonsmokers, healthy smokers, and patients with chronic obstructive pulmonary disease (COPD). Plasma elastin peptide concentrations were significantly higher in subjects with COPD (66.8 +/- 5.8 ng/ml, n = 10) compared with nonsmokers (23.4 +/- 4.6 ng/ml, n = 12), and healthy smokers had intermediate values (36.0 +/- 6.8, n = 6), p less than 0.05. Urine values (both unadjusted and normalized to urine creatinine concentration) were approximately 10-fold higher than plasma in all subject groups, and the relative differences among groups were the same as for plasma with values of 910.8 +/- 105.6, 358.1 +/- 101.2, and 281.0 +/- 67.8 ng/ml for subjects with COPD (n = 10), healthy smokers (n = 6), and healthy nonsmokers (n = 12), respectively. Poor recovery of BALF in COPD subjects reduced differences in the BALF elastin peptide concentrations among subjects groups, although the healthy smokers and COPD subjects tended to have higher amounts. Assuming some dilution due to lavage technique, elastin peptide concentrations were estimated to be substantially higher in epithelial lining fluid than in plasma, suggesting lung as a significant source of elastin peptides in COPD. This is the first application of elastin peptide measurement to human urine or BALF, and we conclude that this assay in urine is useful in characterizing elastin turnover in patients with or at risk for emphysema.
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PMID:Comparison of elastin peptide concentrations in body fluids from healthy volunteers, smokers, and patients with chronic obstructive pulmonary disease. 155 98

The oxidative inactivation of the alpha-1-proteinase inhibitor (alpha 1PI) is one of the mechanisms responsible for creating the elastase/antielastase imbalance during inflammation in the lower respiratory tract. Chronic supremacy of elastase may cause degradation of elastin fibers leading to the pulmonary emphysema. In this study we have investigated the effect of erythrocytes (RBC, concentrations 0.125 to 1.5%) on the oxidative inactivation of alpha 1PI by the phorbol myristate acetate-stimulated polymorphonuclear leukocytes (PMNL) and PMNL myeloperoxidase-H2O2-halide system. During exposure of alpha 1PI to both systems in the presence of RBC the significant protection (p less than 0.001) of alpha 1PI was found for all RBC concentrations, e.g. at RBC concentration of 1% the elastase inhibitory capacity (EIC) of alpha 1PI increased from 0 to 60 +/- 6 and 88 +/- 9% of the control value (untreated alpha 1PI), n = 5, respectively. The preincubation of RBC with chloramine-T (1 mM), inhibition of RBC catalase or depletion of RBC reduced glutathione alone did not diminish the capacity of RBC to protect alpha 1PI. However, these treatments together completely deprived RBC of their protective properties. Moreover, we have compared the decrease in the EIC of human blood and its plasma after incubation with H2O2 (0.1 mM to 0.1 M) or chloramine-T (1 microM to 1 mM). For the incubation with H2O2 no decrease in blood EIC was found whereas in plasma the loss of EIC was already visible at a H2O2 concentration of 0.1 mM. Also for the incubation with chloramine-T the EIC of blood was more resistant to oxidant damage than EIC of plasma. It is suggested that RBC contaminations present in the phagocyte inflammatory infiltration in the lower airways may protect alpha 1PI from oxidative inactivation and thus indirectly diminish proteolytic lung injury related to inflammation.
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PMID:Erythrocytes protect alpha-1-proteinase inhibitor from oxidative inactivation induced by chemicals, the myeloperoxidase-H2O2-halide system and stimulated polymorphonuclear leukocytes. 165 55

SR 26831 ([[5-(2-chloro-benzyl-2-(terbutyloxycarbonyl)]-4,5,6,7- tetrahydrothieno(3,2-c)pyridine]N-oxide) is the first member of a new class of human leukocyte elastase inhibitors. SR 26831 inhibited in a dose-dependent manner elastases from human leukocytes or pancreas with IC50 values of 80 +/- 2.6 nM and 4.8 +/- 0.12 microM, respectively. Steady-state studies revealed that SR 26831 behaved like a noncompetitive, irreversible inhibitor of both types of enzymes. SR 26831 inhibited in a dose-dependent manner degradation of [3H]elastin and [3H]collagens (types I and IV) by human leukocyte elastase (IC50 values were between 1.2 and 1.8 microM). In this respect, SR 26831 was 3- to 20-fold more active than alpha-1-antitrypsin. SR 26831 was also highly selective for elastases inasmuch as it did not inhibit pepsin, collagenase, trypsin, alpha-chymotrypsin, factor Xa, plasmin, kallikrein, cathepsins B, C, D and G and thrombin. In the rabbit, SR 26831 was cleared rapidly from blood after i.v. injection, but affected intracellular leukocyte elastase activity shortly after either i.v. or p.o. administration. In the rat, i.v. or p.o. administration of SR 26831 prevented in a dose-dependent manner acute lung injury induced by intratracheal instillation of human leukocyte elastase. SR 26831 (1 mg/kg) was still efficient when it was administered 90 min before elastase instillation and was also able to limit further hemorrhage development in response to elastase, after it had begun. SR 26831 may therefore be of therapeutic value in the treatment of diseases such as rheumatoid arthritis or pulmonary emphysema thought to be due to the destructive action of leukocyte elastase.
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PMID:Biochemical and pharmacological activities of SR 26831, a potent and selective elastase inhibitor. 173 26

Heparin and its derivatives inhibit human leucocyte proteinases i.e. elastase and cathepsin G, but do not inhibit porcine pancreatic elastase and Pseudomonas aeruginosa elastase. In vitro experiments, reported here, also indicate that elastin, one of the physiological substrates of human leucocyte elastase (HLE), could decrease by 30-fold the inhibitory potential of an hexadecasaccharide heparin fragment (dp 16) isolated from CY 222. Nevertheless, the inhibitory capacity of the heparin fragment still remains elevated with IC50 = 2.7 x 10(-7) M and still inhibits HLE in its free and adsorbed state to elastin. These overall data prompted us to evaluate the influence of CY 222 in HLE-induced emphysema. Emphysema was induced in mice eight weeks old, following a single instillation of 200 micrograms of HLE. CY 222 treated animals received 2.5 mg.kg-1 subcutaneously once daily, 6 days per week during 4 weeks prior to HLE instillation, and for eight weeks following HLE instillation. The heparin fragment treatment of the mice halved the mortality rate observed early following HLE instillation. After 8 weeks, surviving animals were examined for lung histological and morphometrical changes: mean linear intercept (MLI) and internal alveolar area (ISA). The CY 222 heparin fragments exerted a protective effect against HLE-induced emphysema by decreasing by 70% the MLI; these heparin fragments exerted no effect on emphysema induced by pancreatic elastase in hamsters or mice. Heparin derivatives represent a new class of physiological HLE low molecular weight inhibitors capable of preventing HLE-induced emphysema.
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PMID:Prevention of leucocyte elastase-induced emphysema in mice by heparin fragments. 178 73

Degradation of the interstitium of the lung by elastolytic enzymes is thought to be a critical component of the pathogenesis of emphysema. Alveolar macrophages are increased in numbers in cigarette smokers and contain the elastolytic cysteine proteinase cathepsin L. We sought to determine if cigarette smoking induces a change in cathepsin L levels in alveolar macrophages which would, in turn, alter the expression of elastolytic activity. Lysates of smokers' macrophages, assayed at pH 5.50, degraded more than seven times as much [3H]elastin as did lysates from nonsmokers' macrophages (44 +/- 20.8 vs. 6 +/- 1.6 micrograms.10(6) cells-1.24 h-1). Little or no activity was demonstrable at neutral pH. Immunoblots of macrophage lysates demonstrated that smokers' cells contain 3.7 +/- 1.1 times as much 25-kDa cathepsin L antigen as nonsmokers' cells. However, as judged by active site labeling, levels of active cathepsin L in smokers and nonsmokers are indistinguishable, suggesting that most of the 25-kDa antigen found in smokers' macrophages is inactive. Inhibitors of cathepsin L had little effect on lysate elastolytic activity, confirming that an enzyme other than cathepsin L is responsible for the increased elastolytic activity seen in smokers' macrophages. Further experiments demonstrated that this second enzyme(s) has a profile of inhibition indicating that it is a cysteine proteinase with optimal activity at pH 5.50. It is this second elastolytic cysteine proteinase(s) that is induced by exposure to cigarette smoke and is responsible for the sevenfold increase in elastolytic activity found in smokers' macrophage lysates.
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PMID:Cigarette smoking induces an elastolytic cysteine proteinase in macrophages distinct from cathepsin L. 187 15

ICI 186,756 is a representative of a new chemical class of synthetic inhibitors of human neutrophil elastase (HNE). This compound demonstrated competitive inhibition of HNE with a Ki of 3.6 +/- 0.8 x 10(-9) mol/L. The selectivity of ICI 186,756 for HNE versus a variety of enzymes ranged from a minimum of 870-fold to greater than 640,000. The compound effectively inhibited hydrolysis of bovine ligamentum nuchae elastin by HNE. Pretreatment of hamsters with ICI 186,756 up to 2 h before intratracheal administration of HNE inhibited enzyme-induced increases in lung weight, total lavageable red cells, and total lavageable white cells measured 24 h after HNE administration. In contrast, similar lung effects produced by intratracheal administration of porcine pancreatic elastase (PPE) were not inhibited by ICI 186,756. Treatment of hamsters with 43 mumol/kg (sc) of ICI 186,756 for 14 or 28 days modulated the increases in alveolar diameter produced by both PPE and HNE, respectively. It is concluded that ICI 186,756 is a potent, competitive, and selective inhibitor of HNE that may be useful in understanding the role of this enzyme in animal models of various diseases. Furthermore, the maintenance or progression of emphysema-like lesions induced in hamsters by PPE do not appear to be due to the persistence of that enzyme within the lung.
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PMID:Biochemical and pharmacological characterization of ICI 186,756: a novel, potent, and selective inhibitor of human neutrophil elastase. 193 33

The administration of trypsin 24 h before, admixed with, or 24 h after administration of an emphysema-inducing dose of porcine pancreatic elastase (PPE) to hamsters resulted in significantly enhanced destruction of lung tissue as evidenced by mean linear intercept values 4 weeks post PPE. The coadministration of trypsin with a nonemphysema-inducing dose of PPE resulted in a significant destructive lung lesion. Administration of trypsin 24 h before or admixed with human leukocyte elastase (HLE) resulted in a lesion that was significantly reduced relative to that produced by administration of HLE alone. When trypsin was administered 24 h after HLE, no effect on the lesion was observed. In vitro, coincubation of trypsin with PPE resulted in a slight enhancement of rate of hydrolysis of elastin, while coincubation of trypsin with HLE resulted in a significant reduction of the rate of hydrolysis. These results suggest that interaction with other proteases may offer an additional physiological control mechanism to prevent inappropriate tissue destruction.
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PMID:Differential modification of elastase-induced emphysema in hamsters by trypsin. 195 5

The protease-antiprotease hypothesis of emphysema development suggests that degradation of elastin in the lung interstitium may give rise to abnormal quantities of circulating elastin-derived peptides (EDP) during periods of inflammation. Recent studies have shown a relationship between emphysema and high levels of EDP in human plasma. This report characterizes elastin digests on the basis of antigenicity, size, and method of preparation, as well as the size distribution of EDP found in the plasmas of nonsmokers, smokers, and emphysema patients. Gel filtration of elastin digests prepared by hydrolysis of human lung elastin using a low (1:500) ratio of neutrophil elastase to elastin generated a broad protein peak of approximately 70,000 daltons. In contrast, a high (1:25) ratio of neutrophil elastase to human lung elastin gave a broad protein peak, with a size distribution in the 10,000 to 30,000 dalton range. This digest showed distinct immunochemical properties. A polyclonal antibody directed against the low-ratio digest showed a minimum detection of 2 ng/ml for the homologous antigen but required 1,000 ng/ml of the high-ratio digest for detectable inhibition in an indirect ELISA assay. Gel filtration of plasmas from normal nonsmokers and the majority of normal smokers revealed a single immunoreactive EDP fraction of approximately 70,000 daltons. Plasmas from selected normal smokers and emphysema patients with high levels of circulating EDP (greater than 90 ng/ml) fractionated into a complex pattern of peptides in which the 70,000 dalton component represented 50% of the immunoreactive material and several lower molecular weight peptides represented the remaining circulating elastin antigens.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Size distribution of human lung elastin-derived peptide antigens generated in vitro and in vivo. 199 Sep 41

Elastase inhibitors are potential drugs for the control of lung emphysema. Since neutrophils may release elastase in the lung interstitium, elastin and inhibitors may complete locally for the binding of enzyme. To better evaluate the potential activity of antielastases, we have run experiments that mimic this in vivo competition. Elastase was added to mixtures of human lung elastin and inhibitor, and the solubilization of the fibrous substrate was measured as a function of time. Controls in which a synthetic substrate was used instead of elastin were run under identical conditions. We show that the rate constants for the irreversible inhibition of elastase by methoxysuccinyl-Ala2-Pro-Val-chloromethylketone and L-657,229, a substituted beta lactam, are 28- and 63-fold lower with elastin than with a synthetic substrate, respectively. The rate constant decreases with increasing concentrations of elastin, indicating that the inhibition is competitive. Elastin also impairs the potency of the following reversible inhibitors: trifluoroacetyl-Lys-Ala-NH-C6H4-p-C6H11, trifluoroacetyl-Lys-Ala-NH-C6H4-pN(C2H5)2, methoxysuccinyl-Ala2-Pro-Boro-Val-OH, and mucus proteinase inhibitor whose Ki values are 29- to 127-fold higher with elastin than with a synthetic substrate. Again the inhibition is competitive. We conclude that association rate constants of irreversible inhibitors and Ki values of reversible ones may be measured accurately using elastin as a substrate. The kinetic constants measured with elastin and not those determined with synthetic substrates should be used to decide whether a given inhibitor is potent enough to be a physiologic antielastase or a potential antielastase drug.
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PMID:Elastin decreases the efficiency of neutrophil elastase inhibitors. 199 Oct 75

Normal structure and function of the lung parenchyma depend upon elastic fibers. Amorphous elastin is biochemically stable in vitro, and may provide a metabolically stable structural framework for the lung parenchyma. To test the metabolic stability of elastin in the normal human lung parenchyma, we have (a) estimated the time elapsed since the synthesis of the protein through measurement of aspartic acid racemization and (b) modeled the elastin turnover through measurement of the prevalence of nuclear weapons-related 14C. Elastin purified by a new technique from normal lung parenchyma was hydrolyzed; then the prevalences of D-aspartate and 14C were measured by gas chromatography and accelerator-mass spectrometry, respectively. D-aspartate increased linearly with age; Kasp (1.76 x 10(-3) yr(-1) was similar to that previously found for extraordinarily stable human tissues, indicating that the age of lung parenchymal elastin corresponded with the age of the subject. Radiocarbon prevalence data also were consistent with extraordinary metabolic stability of elastin; the calculated mean carbon residence time in elastin was 74 yr (95% confidence limits, 40-174 yr). These results indicate that airspace enlargement characteristic of "aging lung" is not associated with appreciable new synthesis of lung parenchymal elastin. The present study provides the first tissue-specific evaluation of turnover of an extracellular matrix component in humans and underscores the potential importance of elastin for maintenance of normal lung structure. Most importantly, the present work provides a foundation for strategies to directly evaluate extracellular matrix injury and repair in diseases of lung (especially pulmonary emphysema), vascular tissue, and skin.
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PMID:Marked longevity of human lung parenchymal elastic fibers deduced from prevalence of D-aspartate and nuclear weapons-related radiocarbon. 202 48


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