Dietary Dityrosine Induces Oxidative Stress and Mitochondrial-Lipid Imbalance in Mouse Liver via MiR-144-3p-Mediated Downregulation of Nrf2.

Abstract

Dityrosine (DT) is a protein oxidation marker present in many high-protein foods, such as dairy and meat products. Chronic dietary intake of DT induces oxidative stress damage in the liver and impairs energy metabolism. This study aims to investigate the mechanisms underlying the effects of DT on disrupted hepatic energy metabolism. The study investigates hepatic lipid accumulation, redox status imbalance, mitochondrial dysfunction, and energy metabolism disorders in 4-week-old C57BL/6J mice after 35 days of DT (420 µgkg-1 body weight) treatment. Transcriptome sequencing and quantitative real-time PCR in HepG2 cells show that DT mainly acted via miR-144-3p. miR-144-3p targets immune responsive gene 1 (IRG1) and decreases the fumaric acid level in the tricarboxylic acid (TCA) cycle, thereby decreasing nuclear factor erythroid 2-related factor 2 (Nrf2) expression and antioxidant activity. Administration of lycopene, a strong antioxidant, alleviates DT-induced damage in mice, confirming the involvement of the Nrf2 pathway in DT-induced abnormal hepatic lipid metabolism and energy homeostasis.