Abstract
Introduction: Copper is an essential trace element crucial for enzyme synthesis and metabolism. Adequate copper levels are beneficial for maintaining the normal immune function of the spleen. Copper deficiency disrupts the metabolic processes within the spleen and impairs its immune function. This research examines the impact of copper deficiency on the spleen and the potential recovery following copper supplementation. Methods: Weaned mice underwent a 4-week copper-deficient diet, succeeded by 1-week of copper repletion via intraperitoneal copper sulfate injection. Histological examination was used to assess pathological changes in the spleen. Biochemical assays were performed to measure oxidative stress levels in the spleen. ELISA, qPCR, and Western blot were employed to examine alterations in inflammatory markers, immune indicators, and oxidative regulatory factors across various levels. Results: Copper deficiency caused histological damage to the spleen, altered the expression of oxidative stress regulatory pathways (Nrf2, Keap1, and HO-1), and affected the expression of key inflammatory enzymes (iNOS, COX2) and transcription factor NF-κB, leading to oxidative damage. This was reflected by decreased levels of SOD, GSH, and T-AOC, along with increased levels of CAT and MDA. The levels of inflammatory cytokines IL-1β, TNF-α, IL-6, and IL-8 were notably increased. Copper supplementation significantly improved these changes. Conclusions: Copper deficiency leads to spleen tissue damage in mice, affecting the Nrf2 regulatory pathway and inducing oxidative damage. Subsequent copper supplementation with copper sulfate effectively ameliorates the damage caused by copper deficiency.