Trehalose suppresses cadmium-activated Nrf2 signaling pathway to protect against spleen injury

Cadmium (Cd), as a kind of ubiquitous and highly toxic heavy metal pollutants, has been known to result in immunotoxicity in animals. As a multifunctional bioactivity disaccharide, trehalose (Tre) is characterized by antioxidative, antiapoptotic, and accelerating autophagy. In this study, Sprague-Dawley (SD) rats were fed with cadmium chloride (CdCl2) and/or Tre to explore the molecular mechanisms of Tre-protected against spleen injury caused by Cd exposure. Firstly, the results showed that Tre partially recovered splenic pathological changes induced by Cd exposure. Secondly, Tre dramatically declined the level of methane dicarboxylic aldehyde (MDA) and elevated the level of total antioxidant capacity (T-AOC) to weaken oxidative stress caused by Cd exposure in spleen tissue. Moreover, the results showed that Tre significantly suppressed Cd-induced the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) and up-regulated the protein expression of nuclear Nrf2. Thirdly, Tre remarkably reduced the protein expression of sequestosome 1 (p62/SQSTM1) and microtubule-associated protein light chain 3II (LC-3II) to restore autophagy inhibition induced by Cd exposure. Finally, the results of TUNEL and the expression of apoptosis marker proteins showed that Tre significantly inhibited Cd-induced apoptosis in spleen tissue to exert its protective effects. In summary, the results indicated that Tre modulated Nrf2 signaling pathway, which interacted with apoptosis and autophagy to against Cd-induced spleen injury, providing potential therapeutic strategies for the prevention and treatment of Cd-related immune system diseases.