Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04040 (Catalase)
 3,577 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A procedure for measuring the oxidant content of aqueous condensates of tobacco cigarette smoke is described. The procedure was used in conjunction with analysis of the ability of the smoke solutions to inactivate the elastase inhibitory capacity (EIC) of alpha 1-antitrypsin. The ability of the smoke of a brand to inactivate alpha 1-antitrypsin correlates well with the known tar and nicotine and with the amount of oxidants as measured using o-dianisidine. Filters were found to remove about 73% of the oxidants from smoke. Smoke from a commercial nontobacco cigarette was also found to contain a significant amount of oxidants and to also destroy alpha 1-antitrypsin. Catalase and superoxide dismutase reduce the effect of solutions containing smoke on the EIC of alpha 1-antitrypsin, suggesting that peroxides and superoxide anions in smoke contribute to the oxidant capacity of the smoke. The extent of apparent oxidation by a given quantity of smoke condensate increases for as long as an hour from the time the condensate is collected. The addition of hydrogen peroxide to the smoke solution increases both its oxidant content and its ability to inactivate alpha 1-antitrypsin. These data suggest that occurrence of hydrogen peroxide caused by secretion from macrophages found in the small airways of smokers may contribute to a locally damaging environment for alpha 1-antitrypsin in the presence of cigarette smoke that could promote the development of centrilobular emphysema.
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PMID:Reduction of the elastase inhibitory capacity of alpha 1-antitrypsin by peroxides in cigarette smoke: an analysis of brands and filters. 697 63

Mineral dust exposure can result in emphysema and chronic airflow obstruction. We postulated that dust-induced emphysema has a pathogenesis similar to that in cigarette smoke-induced emphysema, namely, excess release of proteolytic enzymes from dust-evoked inflammatory cells, and inactivation of alpha-1-antitrypsin (A1AT) by dust-catalyzed formation of oxidants. To test this theory we examined the antiproteolytic activity of A1AT exposed to quartz in vitro and found that it was decreased in a dose-response fashion. Catalase prevented this effect, which suggested that it was mediated by quartz-generated hydrogen peroxide. We also showed that a variety of dusts could oxidize methionine to methionine sulfoxide in vitro, using either pure amino acid or whole protein. The relative order of activity was coal > quartz > titanium dioxide. Lastly, we used a new high-performance liquid chromatography technique to demonstrate that quartz, coal, and titanium dioxide produced connective tissue breakdown in rat lungs, as determined by the appearance of desmosine and hydroxyproline in lavage fluid after dust instillation. On a particle-for-particle basis, the order of dust potency was similar to that for methionine oxidation. Connective tissue breakdown was associated with elevations of both polymorphonuclear leukocytes and macrophages in lavage fluid, and it is unclear whether one or both of these types of inflammatory cell mediates this process. These observations support our theory that dust-induced emphysema and smoke-induced emphysema occur through similar mechanisms.
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PMID:Mechanisms of mineral dust-induced emphysema. 940 Jul 26

This study aimed to investigate bronchiolar catalase expression and its relationship with smoking and/or chronic obstructive pulmonary disease (COPD) in humans and to determine the dynamic change of bronchiolar catalase expression in response to cigarette smoke in mice. Lung tissue was obtained from 36 subjects undergoing surgery for peripheral tumours, consisting of life-long nonsmokers and smokers with or without COPD. Male C57BL/6 mice were subjected to cigarette smoke exposure for up to 3 months followed by a 28-day cessation period. We quantified bronchiolar catalase mRNA using laser capture microdissection and quantitative reverse transcription-polymerase chain reaction. C22 club cells (Clara cells) in culture were exposed to cigarette smoke extract and monitored for viability when catalase expression was decreased by siRNA. Catalase was decreased at mRNA and protein levels in bronchiolar epithelium in smokers with COPD. In mice, bronchiolar catalase is temporarily upregulated at 1 day after cigarette smoke exposure but is downregulated by repeated cigarette smoke exposure, and is not restored long after withdrawal once emphysema is developed. Decreasing catalase expression in C22 cells resulted in greater cigarette smoke extract-induced cell death. Bronchiolar catalase reduction is associated with COPD. Regulation of catalase depends on the duration of cigarette smoke exposure, and plays a critical role for protection against cigarette smoke-induced cell damage.
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PMID:Bronchiolar epithelial catalase is diminished in smokers with mild COPD. 2310 May 9