Effects of hypoxia on expression of superoxide dismutases in cultured ATII cells and lung fibroblasts

Robert M. Jackson, Gregory Parish, Ye Shih Ho

Research output: Contribution to journalArticle

38 Scopus citations

Abstract

This study investigated whether hypoxia affected the expression of mitochondrial manganese-containing superoxide dismutase (Mn-SOD) and the cytosolic copper and zinc-containing superoxide dismutase (Cu,Zn-SOD) in alveolar type II epithelial (ATII) cells and lung fibroblasts. Cells were exposed in vitro to air (controls) or to 2.5% oxygen (hypoxia) for 24 h. Mn- SOD and Cu,Zn-SOD mRNA expression was measured by quantitative reverse transcriptase-polymerase chain reaction. Both Mn-SOD and Cu,Zn-SOD mRNA expression in ATII cells decreased significantly after 1 day in hypoxic conditions. The decrease in Mn-SOD mRNA (-69%) was greater than that in Cu,Zn-SOD mRNA (-48%). ATII cell surfactant protein A transcript expression remained constant. Mn-SOD (-52%) and Cu,Zn-SOD (-54%) mRNA expression decreased similarly in lung fibroblasts cultured during hypoxia. The half- life of the Mn-SOD mRNA measured in lung fibroblasts exposed to air or hypoxia for 24 h decreased significantly from 5.8 ± 0.1 to 3.8 ± 0.7 h (- 34%). The half-life for the Cu,Zn-SOD decreased significantly from 4.0 ± 0.3 to 2.4 ± 0.1 h (-40%). Neither Mn-SOD nor Cu,Zn-SOD protein expression in ATII cells changed significantly during hypoxia. Hypoxia decreases expression of Mn-SOD and Cu,Zn-SOD mRNA in ATII cells and lung fibroblasts in part by decreasing stability of the mRNA transcripts.

Original languageEnglish (US)
Pages (from-to)L955-L962
JournalAmerican Journal of Physiology - Lung Cellular and Molecular Physiology
Volume271
Issue number6 15-6
DOIs
StatePublished - Dec 1996

Keywords

  • alveolar epithelium
  • hypoxia

ASJC Scopus subject areas

  • Pulmonary and Respiratory Medicine
  • Cell Biology
  • Physiology
  • Physiology (medical)

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