Abstract
Orphan nuclear receptor 4A1 (NR4A1) is a member of the NR4A subfamily that was initially discovered as an intermediate early gene expressed in response to stressors, including inflammatory agents. This review addresses the hypothesis that NR4A1 is a key nutrient sensor that contributes to the anti-aging and health-protective effects of receptor ligands, dietary phenolics, and other diet-derived compounds. There is evidence in animal models including humans that NR4A1 serves as an important gene that decreases the rate of aging and its associated diseases. For example, in humans and mice, NR4A1 expression decreases with age and loss of NR4A1 enhances disease susceptibility, and survival curves show that NR4A1-deficient mice live 4 months less than wild-type animals. An extensive comparison of inflammatory diseases, immune dysfunction, and fibrosis in multiple tissues shows that in NR4A1(-/-) mice and rats these diseases and injuries are enhanced compared to wild-type NR4A1(-/-) animals. There is evidence showing that structurally diverse NR4A1 ligands reverse the induced adverse effects in NR4A1 wild-type mice. This raises an important question regarding the mechanisms of NR4A1-dependent inhibition of the aging process and the potential for this receptor as a nutrient sensor. It has been well established that polyphenolics, including flavonoids, resveratrol, and other compounds in the diet, are health-protective and decrease the aging process. Recent studies show that resveratrol and flavonoids such as quercetin and kaempferol bind NR4A1 and exhibit protective NR4A1-dependent inhibition of endometriosis and cancer. These limited studies support a role for NR4A1 as a potential dietary sensor of nutrients that are known to be health-protective and a potential nutrient target for improving health.