Consequences of acute and chronic oxidative stress upon the expression pattern of proteins in peripheral blood mononuclear cells.

Oxidative stress accompanies various diseases associated with chronic inflammation, including cancer. We exposed human peripheral blood mononuclear cells (PBMCs) to hydrogen peroxide in autologous plasma imitating in vivo conditions. Proteome alterations of metabolically labeled cells were recorded by means of 2D gel electrophoresis in addition to shotgun analysis. Cells displayed a distinct stress response and down-regulated manganese superoxide dismutase, while a large number of other redox-regulating enzymes remained unaffected. In the second part of the experiment, we isolated PBMCs from cancer patients to analyze primary cells exposed to chronic oxidative stress. Plasma peroxidation levels of the patients were significantly higher than those of age and sex-matched controls. The corresponding cells displayed significant proteome alterations which appear to be related to inflammation and apoptosis regulation. The present data, fully accessible via PRIDE (accessions 3844-59), may be the first step in the design of a combined protein assay specifically indicating oxidative stress in human PBMCs.