Respiratory syncytial virus inhibits lung epithelial Na+ channels by up-regulating inducible nitric-oxide synthase.
Weifeng Song, Gang Liu, Charles A Bosworth, John R Walker, George A Megaw, Ahmed Lazrak, Edward Abraham, Wayne M Sullender, Sadis Matalon
文献索引:J. Biol. Chem. 284(11) , 7294-306, (2009)
全文:HTML全文
摘要
Respiratory syncytial virus (RSV) infection has been shown to reduce Na+-driven alveolar fluid clearance in BALB/c mice in vivo. To investigate the cellular mechanisms by which RSV inhibits amiloride-sensitive epithelial Na+ channels (ENaC), the main pathways through which Na+ ions enter lung epithelial cells, we infected human Clara-like lung (H441) cells with RSV that expresses green fluorescent protein (rRA2). 3-6 days later patch clamp recordings showed that infected cells (i.e. cells expressing green fluorescence; GFP+) had significantly lower whole-cell amiloride-sensitive currents and single channel activity (NPo) as compared with non-infected (GFP-), non-inoculated, or cells infected with UV-inactivated RSV. Both alpha and beta ENaC mRNA levels were significantly reduced in GFP+ cells as measured by real-time reverse transcription-PCR. Infection with RSV increased expression of the inducible nitric-oxide synthase (iNOS) and nitrite concentration in the culture medium; nuclear translocation of NF-kappaB p65 subunit and NF-kappaB activation were also up-regulated. iNOS up-regulation in GFP+ cells was prevented by knocking down IkappaB kinase gamma before infection. Furthermore, pretreatment of H441 cells with the specific iNOS inhibitor 1400W (1 microM) resulted in a doubling of the amiloride-sensitive Na+ current in GFP+ cells. Additionally, preincubation of H441 cells with A77-1726 (20 microM), a de novo UTP synthesis inhibitor, and 1400W completely reversed the RSV inhibition of amiloride-sensitive currents in GFP+ cells. Thus, both UTP- and iNOS-generated reactive species contribute to ENaC down-regulation in RSV-infected airway epithelial cells.
相关化合物
相关文献:
2011-08-01
[Toxicol. Sci. 122(2) , 579-86, (2011)]
2010-12-01
[Cell Death Differ. 17(12) , 1882-95, (2010)]
2012-10-01
[Am. J. Respir. Cell. Mol. Biol. 47(4) , 543-51, (2012)]
2011-11-16
[Eur. J. Pharmacol. 670(1) , 304-10, (2011)]
2010-02-01
[Bioorg. Med. Chem. Lett. 20(3) , 1284-7, (2010)]