Abstract
OBJECTIVE: Atheroprotective blood flow induces expression of anti-inflammatory Krüppel-like factor 2 (KLF2) and activates antioxidant transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) in vascular endothelium. Previously, we obtained KLF2-induced gene expression profiles in ECs, containing several Nrf2 target genes. Our aim was to investigate the role of KLF2 in shear stress-mediated activation of Nrf2 in human umbilical vein endothelial cells (HUVECs).
METHODS AND RESULTS: Expression of Nrf2 and its targets NAD(P)H dehydrogenase quinone 1 (NQO1) and heme oxygenase (HO-1) was elevated by shear and KLF2. KLF2 knockdown showed that shear-induced expression of NQO1 but not Nrf2 was dependent on KLF2. KLF2 overexpression in absence of flow resulted in more efficient activation of Nrf2 by tert-butyl hydroquinone (tBHQ) through enhanced nuclear localization, and promoted expression of a large panel of Nrf2-dependent genes resulting in superior protection against oxidative stress. Comparison of shear-, KLF2-, and Nrf2-induced transcriptomes showed that the majority of shear-modulated gene sets is influenced by KLF2 or Nrf2.
CONCLUSIONS: We report that KLF2 substantially enhances antioxidant activity of Nrf2 by increasing its nuclear localization and activation. The synergistic activity of these two transcription factors forms a major contribution to the shear stress-elicited transcriptome in endothelial cells.
Original language | English |
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Pages (from-to) | 1339-46 |
Number of pages | 8 |
Journal | Arteriosclerosis, Thrombosis and Vascular Biology |
Volume | 28 |
Issue number | 7 |
DOIs | |
Publication status | Published - Jul 2008 |
Keywords
- Active Transport, Cell Nucleus
- Antioxidants
- Cells, Cultured
- Endothelial Cells
- Enzyme Induction
- Gene Expression Profiling
- Gene Regulatory Networks
- Heme Oxygenase-1
- Humans
- Kruppel-Like Transcription Factors
- NAD(P)H Dehydrogenase (Quinone)
- NF-E2-Related Factor 2
- Oxidants
- Oxidative Stress
- Pulsatile Flow
- RNA Interference
- RNA, Small Interfering
- Stress, Mechanical
- Transfection
- Up-Regulation
- tert-Butylhydroperoxide