Arterial flow reduces oxidative stress via an antioxidant response element and Oct-1 binding site within the NADPH oxidase 4 promoter in endothelial cells
| Autor: | Henning Morawietz, Claudia Goettsch, Andreas H. Wagner, Coy Brunssen, Claudia Haschke, Melanie Brux, Nicole Duerrschmidt, Stefan R. Bornstein, Gregor Muller, Winfried Goettsch |
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| Rok vydání: | 2010 |
| Předmět: |
Physiology
NF-E2-Related Factor 2 Response Elements Antioxidants Small hairpin RNA chemistry.chemical_compound Downregulation and upregulation Physiology (medical) Humans Binding site Promoter Regions Genetic Transcription factor Octamer transcription factor Cells Cultured NADPH oxidase Binding Sites biology urogenital system Superoxide NOX4 Endothelial Cells NADPH Oxidases Molecular biology Oxidative Stress chemistry NADPH Oxidase 4 Regional Blood Flow cardiovascular system biology.protein Stress Mechanical Cardiology and Cardiovascular Medicine Reactive Oxygen Species Octamer Transcription Factor-1 |
| Zdroj: | Basic research in cardiology. 106(4) |
| ISSN: | 1435-1803 |
| Popis: | The main sources of oxidative stress in the vessel wall are nicotine adenine dinucleotide phosphate (NADPH) oxidase (Nox) complexes. The endothelium mainly expresses the Nox4-containing complex; however, the mechanism by which shear stress in endothelial cells regulates Nox4 is not well understood. This study demonstrates that long-term application of arterial laminar shear stress using a cone-and-plate viscometer reduces endothelial superoxide anion formation and Nox4 expression. In primary human endothelial cells, we identified a 47 bp 5′-untranslated region of Nox4 mRNA by 5′-rapid amplification of cDNA ends (5′-RACE) PCR. Cloning and functional analysis of human Nox4 promoter revealed a range between −1,490 and −1,310 bp responsible for flow-dependent downregulation. Mutation of an overlapping antioxidative response element (ARE)-like and Oct-1 binding site at −1,376 bp eliminated shear stress-dependent Nox4 downregulation. Consistent with these observations, electrophoretic mobility shift assays (EMSA) demonstrated an enhanced shear stress-dependent binding of Nox4 oligonucleotide containing the ARE-like/Oct-1 binding site, which could be inhibited by specific antibodies against the transcription factors nuclear factor erythroid 2-related factor 2 (Nrf2) and octamer transcription factor 1 (Oct-1). Furthermore, shear stress caused the translocation of Nrf2 and Oct-1 from the cytoplasm to the nucleus. Knockdown of Nrf2 by short hairpin RNA (shRNA) increased Nox4 expression twofold, indicating a direct cross-talk between Nrf2 and Nox4. In conclusion, an ARE-like/Oct-1 binding site was noticed to be essential for shear stress-dependent downregulation of Nox4. This novel mechanism may be involved in the flow-dependent downregulation of endothelial superoxide anion formation. |
| Databáze: | OpenAIRE |
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