Oxidative stress is important in several pathologies, including cardiovascular diseases such as atherosclerosis and cardiac ischemia-reperfusion injury. An important mechanism for adaptation to oxidative stress is induction of genes through the antioxidant response element (ARE), which regulates the expression of antioxidant and cytoprotective genes via the transcription factor Nrf2 (nuclear factor E2-related factor 2). As Nrf2-regulated genes are induced during oxidant stress occurring, for example, in reperfusion after ischemia, we took a novel approach to exploit ARE for the development of oxidative stress-inducible gene therapy vectors. To this end, one, two or three ARE-containing regions from human NAD(P)H:quinone oxidoreductase-1, glutamate-cysteine ligase modifier subunit and mouse heme oxygenase-1 were cloned into a vector expressing luciferase under a minimal SV40 promoter. The construct, which was the most responsive to ARE-inducing agents, was chosen for further studies in which a lentiviral vector was produced for an efficient transfer to endothelial cells. Heme oxygenase-1 (HO-1), which has well-characterized anti-inflammatory properties, was used as the therapeutic transgene. In human endothelial cells, AREdriven HO-1 overexpression inhibited nuclear factor-kB activation and subsequent vascular cell adhesion molecule-1 expression induced by tumor necrosis factor-a. We conclude that the ARE element is a promising alternative for the development of oxidative stress-inducible gene therapy vectors.

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