Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0242706 (hyperoxia)
 5,219 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The lung epithelium resorbs alveolar fluid through combined action of sodium channels and the sodium pump, Na,K-ATPase. The lung often is exposed to hyperoxia in disease states and hyperoxia generates a mixture of reactive oxygen species. In vivo and in vitro exposure of rat lung and alveolar type II cells, respectively, increases gene expression of both alpha-1 and beta-1 subunits of the sodium pump. In contrast to the primary type II cells, several type II cell lines did not increase sodium pump gene expression with hyperoxia, but the renal tubular epithelial MDCK cell line did. Using promoter-receptor constructs transfected into MDCK cells, hyperoxia did not markedly increase transcription of the alpha-1 subunit but doubled transcription of the beta-1 subunit gene. Using 5'-deletion constructs, the region required for the beta-1 increase was localized to a 40-base pair region from -44/-84. The hyperoxic responsiveness of this region was confirmed using constructs with one or two copies of this region placed in minimal promoter-luciferase reporters. This 5' promoter region contains a consensus binding sequence for SP-1, a basal transcription factor but not for binding of other known transcription factors. Thus, hyperoxia induces Na,K-ATPase beta-1 promoter transcription, likely acting through a novel mechanism.
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PMID:Oxidant effects on epithelial Na,K-ATPase gene expression and promoter function. 978

Treatment of neonatal RDS in premature infants with intratracheal administration of natural surfactant has become gold standard therapy. Natural surfactant preparations mainly contain, apart from phospholipids, the surfactant associated proteins B and C (SP-B and SP-C). Both proteins are synthesized mainly in alveolar type-II cells and Clara-cells, SP-B, also in the gastrointestinal tract and the auditive tube. SP-B is encoded on chromosome 2 over a region with 11 exons, whereas the SP-C gene is localized on chromosome 8 in a region containing 6 exons. Transcription of both SP-B and SP-C is induced by TTF-1. Furthermore SP-1 and SP-3 are known as transcription factors for SP-B. The main function of SP-B and SP-C is to maintain physiologic surface properties enabeling adequate lung mechanics. A complete SP-B deficiency following homozygous mutations in the SP-B gene (e. g. 121-ins 2-mutation) therefore leads to severe respiratory failure postnatally, due to the lack of functional surfactant. On the other hand complete deficiency of SP-C causes chronic interstitial pneumonitis as well in infants as in adults depending on disease-modifiers yet unknown. Besides the surface tension lowering property, SP-B reveals immunological functions regarding its interaction with different proinflammatory cellular systems as well as other inflammatory mediators, e. g. following hyperoxia. For SP-C first studies have described modulation of inflammatory reactions in macrophages, suggesting similar immune-modulatory effects. Whereas basic effects on lung mechanisms of both lipophilic surfactant proteins seem to be well understood, their immunologic local pulmonary functions and effects on surfactant metabolism require further investigations.
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PMID:[Surfactant-associated proteins B and C: molecular biology and physiologic properties]. 1522 16