Transcription profiling of human vascular smooth muscle cells treated with glucose oxidase and human haemoglogib reveals ferrous hemoglobin can protect vascular smooth muscle cells from hydrogen peroxide-induced oxidative stress response and cell damage

ABSTRACT: Hemoglobin (Hb) is released from red blood cells (RBC) during intravascular hemolysis. Cell free Hb has been implicated to play a pathogenic role in hemolytic diseases such as sickle cell anemia or malaria. Hydrogen peroxide (H2O2) is the most prevalent reactive oxygen species which is produced in excess during inflammation or tissue injury and has been included as a potential mediator of oxidative stress related cell and tissue damage. The biologic significance of Hb’s peroxidase activity as an anti-oxidant is controversial as the radicals and higher oxidation iron species which are potentially released during these reactions could be a source of exaggerated oxidative damage. Using a cell culture model of low-flux continuous H2O2 generation by glucose-oxidase (GOx) Hb revealed the potential to protect vascular smooth muscle cells and macrophages from H2O2 mediated glutathione depletion and cell death. As revealed by gene array analysis, Hb effectively abolished H2O2 induced oxidative stress response in these cells. Through electron microscopy and quantitative mass spectrometry extensive oxidation of specific Hb amino acid residues, polymerization and precipitation was defined. This may be a consequence of potential protective mechanism within Hb. The net biologic effect of Hb, when present in oxidative rich environments, is likely a result of the balance of H2O2 consumption (protection) on one hand and the production of free radicals (damage) on the other hand. Further the extensive structural changes occurring during the reaction of ferrous Hb with H2O2 could 'absorb' a significant amount of oxidative impact and thereby further protect the environment from heme derived free radical damage. The intrinsic peroxidase activity of hemoglobin seems to be a constitutive 'enzymatic' function of Hb which adds a novel facet to the multivalent role played by the abundant oxygen carrier protein.

ORGANISM(S): Homo sapiens

SUBMITTER: Corinne Widmer 

PROVIDER: E-MEXP-2263 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress