Na,K-ATPase gene transfer mitigates an oxidant-induced decrease of active sodium transport in rat fetal ATII cells

Academic Article

Abstract

  • We investigated whether adenovirus-mediated transfer of genes encoding for subunits of the Na,K-ATPase increases transepithelial Na transport in rat fetal distal lung epithelial (FDLE) monolayers and renders them more resistant to hydrogen peroxide injury. FDLE cells, isolated from rat fetuses at a gestational age of 19 to 20 d (22 d = term), were seeded on filters and infected with replication-incompetent human type 5 adenoviruses containing complementary DNAs encoding for rat Na,K-ATPase α or β subunits (adα and adβ , respectively). Once confluent monolayers were formed, the filters were mounted in Ussing chambers and short circuit currents (l ) were measured. Increased levels of α or β subunit proteins after infection with adα and adβ , respectively, were confirmed by Western blot analysis. Baseline l increased after transfection with 2 plaque-forming units (pfu) of adβ from 5.1 ± 0.3 to 6.1 ± 0.3 μA/cm (mean ± SEM; P < 0.05). Permeabilization of the apical membrane with amphotericin B caused a large increase in l ; the ouabain-sensitive component of the amphotericin B-elicited l (ouab ) was increased from 4.0 ± 0.2 (n = 69) in controls to 4.8 ± 0.2 (n = 15), 5.9 ± 0.3 (n = 53), 6.9 ± 0.4 (n = 25), 7.7 ± 0.9 (n = 16) in monolayers infected with 1, 2, 11, and 22 pfu of adβ , respectively; transfection with adα had no effect on any measured variables. Further, transfection with adβ in comparison to noninfected monolayers resulted in higher baseline and ouab l after injury with 500 μM H O . We conclude that overexpression of the β subunit of the Na,K-ATPase may help maintain normal levels of vectorial Na transport across ATII cell monolayers in pathologic conditions. + 2 + 1 1 1 1 sc 1 1 1 1 sc 1 sc sc max 1 1 1 max sc 2 2 1
  • Authors

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    Author List

  • Thome U; Chen L; Factor P; Dumasius V; Freeman B; Sznajder JI; Matalon S
  • Start Page

  • 245
  • End Page

  • 252
  • Volume

  • 24
  • Issue

  • 3