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Nitric oxide‐mediated inhibition of lipopolysaccharide‐induced apoptosis in pulmonary artery endothelial cells
Author(s) -
StittFischer Molly S.,
Wasserloos Karla J.,
Reynolds Paul R.,
Pitt Bruce R.
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.6.lb125-a
Subject(s) - nitric oxide , apoptosis , lipopolysaccharide , nitric oxide synthase , chemistry , microbiology and biotechnology , endothelium , biochemistry , biology , immunology , endocrinology , organic chemistry
Increased levels of apoptosis in endothelial cells have been implicated in the progression of acute lung injury. Nitric oxide (NO), with both cytotoxic and protective effects depending upon dose, may also play a role in lung pathogenesis. Our laboratory is continuing to investigate the mechanisms leading to NO‐induced protection from apoptosis in pulmonary endothelial cells. We exposed cultured sheep pulmonary artery endothelial cells (SPAEC) that overexpressed inducible nitric oxide synthase (iNOS) after somatic gene transfer (SPAEC.iNOS) to lipopolysaccharide (LPS) and quantified apoptosis via caspase 3/7 activity. We also measured cellular nitric oxide production by Greiss assay. Finally, we used a fluorescent modification of the biotin‐switch method in combination with two dimensional gel electrophoresis and MALDI‐TOF mass spectroscopy to analyze changes in S‐nitrosation of the proteome in LPS‐treated SPAEC.iNOS. We confirmed our previous report (Am. J. Physiol. 275: –L728, 1998) that SPAEC.iNOS were resistant to LPS mediated apoptosis, and that this resistance was sensitive to L‐NAME, an iNOS inhibitor. Proteomic analyses revealed several newly nitrosated proteins that may be candidates for NO mediated resistance. Although the mechanism of NO‐mediated inhibition of apoptosis in endothelium and other cells is still largely unknown, these results indicate the utility of proteomic methods to help elucidate the role of S‐nitrosated proteins in this process.