Abstract
Selenium (Se) and vitamin E are antioxidant micronutrients. Se functions through selenoproteins and vitamin E reacts with oxidizing molecules in membranes. The relationship of these micronutrients with the Nrf2-antioxidant response element (ARE) pathway was investigated using ARE-reporter mice and Nrf2-/- mice. Weanling males were fed Se-deficient (0 Se), vitamin E-deficient (0 E), or control diet for 16 or 22 weeks. The ARE reporter was elevated 450-fold in 0 Se liver but was not elevated in 0 E liver. Antioxidant enzymes induced by Nrf2-ARE (glutathione S-transferase (GST), NAD(P)H quinone oxidoreductase (NQOR), and heme oxygenase-1 (HO-1)) were elevated in 0 Se livers but not in 0 E livers. Deletion of Nrf2 had varying effects on the inductions, with GST induction being abolished by it but induction of NQOR and HO-1 still occurring. Thus, Se deficiency, but not vitamin E deficiency, induces a number of enzymes that protect against oxidative stress and modify xenobiotic metabolism through Nrf2-ARE and other stress-response pathways. We conclude that Se deficiency causes cytosolic oxidative stress but that vitamin E deficiency does not. This suggests that the oxidant defense mechanisms in which these antioxidant nutrients function are independent of one another.
Original language | English (US) |
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Pages (from-to) | 1617-1623 |
Number of pages | 7 |
Journal | Free Radical Biology and Medicine |
Volume | 44 |
Issue number | 8 |
DOIs | |
State | Published - Apr 15 2008 |
Externally published | Yes |
Keywords
- Cytosolic oxidant defense network
- Free radicals
- Mouse liver
- Nrf2 ARE pathway
- Oxidative stress
- Phase II enzymes
- Selenium deficiency
- Vitamin E deficiency
ASJC Scopus subject areas
- Biochemistry
- Physiology (medical)