Gene expression profiling in cultured cells, the role of GPx-1 in hypoxia-reoxygenation and ischemia-reperfusion

• Applicant: Dr. Edith Lubos
• Subject Area: Cardiology, Angiology
• Term: from 2006 to 2009
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 35961772

Cellular glutathione peroxidase (GPx)-1, a selenocysteine-containing enzyme, plays a central role in protecting cells from oxidative injury. GPx-1 is ubiquitously expressed in eukaryotic cells where it reduces hydrogen and lipid peroxides to alcohols. In patients with coronary artery disease, a low level of activity of red-cell GPx-1 is independently associated with an increased risk of cardiovascular events and may have prognostic value in addition to that of traditional risk factors.1 Based on these results we focus our interest in finding the GPx-1 molecular pathology mechanisms in endothelial cells by first identifying early changes in gene expression profiles induced by reactive oxygen species, such as hydrogen peroxide (H2O2) and second by proinflammatory cytokine, such as tumor necrosis factor (TNF)-α treatment at variable times. Using this model, the modification of GPx-1 expression, by siRNA knockdown to reduce enzyme levels or increase GPx-1 levels by selenium treatments or transfection of recombinant GPx-1, and measure the effects of modulating GPx-1 levels on gene expression is done. In a cellular model for ischemia/reperfusion injury the influence of GPx-1 on gene expression profiles are tested under conditions of hypoxia/reoxygenation or during homocysteine treatments. With the experience in gene expression profiling in cell culture we are able to establish these methods to investigate the molecular pathology mechanisms of other biomarkers in patients with or without cardiovascular disease, aid drug discovery and provide a clearer understanding of complex biological systems.

• DFG Programme: Research Fellowships
• International Connection: USA
• Host: Professor Dr. Joseph Loscalzo