Dehydroepiandrosterone alters retinol status and expression of the β-Carotene 15,15ʹ-Monooxygenase and lecithin:Retinol acyltransferase genes

Abstract

Dehydroepiandrosterone (DHEA) and its sulfate ester DHEA-sulfate (DHEA-S) are the most abundant adrenal steroids in humans. DHEA has a critical role as a steroidal precursor of androgens and/or estrogens, and in human studies and animal experiments, both DHEA and DHEA-S have multiple benefi cial effects. However, there are few reports regarding the relationship between DHEA and nutrient status, especially for vitamins. Therefore, we elucidated the effect of DHEA administration on retinol status. Wistar rats were fed with a standard diet containing 0.4% (wt/wt) DHEA for 2 wk. We assessed retinol status and the expression of retinol-related proteins, including metabolic enzymes, binding proteins, cytochrome P450 (CYP) enzymes, and antioxidant enzymes. Retinol levels in the plasma and the liver of DHEA-fed rats were lower than those of controls. Expression of β -carotene 15,15ʹ-monooxygenase (BCMO) in the liver and intestine of DHEA-fed rats was lower, whereas BCMO expression in the testes of DHEA-fed rats was higher than that of controls. Expression of the retinol-metabolizing aldehyde dehydrogenase (ALDH) enzyme ALDH1A2 was repressed in the liver of DHEA rats, whereas ALDH1A1 expression was unaltered. Hepatic expression of lecithin:retinol acyltransferase (LRAT) and CYP26A1 was lower in DHEA-fed rats than in controls. Retinol status in DHEA-fed rats might be affected by altered BCMO expression in the liver and intestine and hepatic LRAT expression, whereas BCMO expression in peripheral tissues may be regulated in a tissue-specifi c manner. We have shown that DHEA administration may infl uence retinol status and the expression of retinolrelated proteins.