Effects of imbalance of mineral elements on peripheral neutrophil metabolism in sheep

The imbalance of mineral element homeostasis in animals is common, causing animal immune dysfunction. Ten female sheep were randomly selected and injected with 4% (w/v) Na2EDTA through a central venous catheter to establish the mineral element imbalance model, then divided into control group (before injection) and Ethylene Diamine Tetraacetic Acid (EDTA) group (after injection). Isolation of peripheral blood neutrophils for mineral elements content determination was done using Inductively coupled plasma-mass spectrometry (ICP-MS) and nontargeted metabolomics analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The ICP-MS results showed that Hg and Cs levels in neutrophils were significantly lower after injection than before (P < 0.05), but had no significant effects on other elements. Our previous study showed that serum Zn, P, K, and other 11 elements were significantly lower after the injection of Na2EDTA than before. LC-MS/MS results showed that differential metabolites are mainly involved in amino acid metabolism, lipid metabolism, and nucleotide metabolism; monoamine metabolism was weakened; and polyamine metabolism was enhanced. Under positive and negative ion modes, the mineral elements P, K, Ca, Mn, Cu, and Zn had the highest correlation with the differential metabolites of neutrophils, followed by Se, and the correlation between each mineral element and different differential metabolites was also different. The results indicated that the imbalance in mineral elements affected the metabolism of sheep neutrophils, these may affect neutrophil function, and Na2EDTA could help to reduce the level of heavy metals in the body of sheep. Our data may provide a theoretical basis for the precise regulation of animal immune metabolism by modern animal husbandry nutrition.