Aberrant Gene Expression of Selenoproteins in Chicken Spleen Lymphocytes Induced by Mercuric Chloride

Mercury (Hg) is a heavy metal widely distributed in ecological environment, poisoning the immune system of humans and animals. Selenium (Se) is an essential microelement and selenoproteins involved in the procedure of Se antagonizing organ toxicity induced by heavy metals. The aim of this research was to investigate the changes of gene expression profile of selenoproteins induced by mercuric chloride (HgCl₂) in chicken spleen lymphocytes. We established cytotoxicity model of chicken spleen lymphocytes by HgCl₂ exposure, the messenger RNA (mRNA) expression levels of 25 selenoproteins in spleen lymphocytes were analyzed by real-time quantitative PCR (qPCR), and the gene expression pattern of selenoproteins was revealed by principal component analysis (PCA). The results showed that the mRNA expression levels of 13 selenoproteins (GPX3, GPX4, TXNRD2, TXNRD3, DIO2, SELENOS, SELENON, SELENOT, SELENOO, SELENOP, SELENOP2, MSRB1, and SEPHS2) were decreased in HgCl₂ treatment group, and there was strong positive correlation between these selenoproteins and component 1 as well as component 2 of the PCA. At the same time, the protein expression levels of GPX4, TXNRD1, TXNRD2, SELENOM, SELENOS, and SELENON were detected by Western blotting, which were consistent with the changes of gene expression. The results showed that the expression levels of selenoproteins were aberrant in response to HgCl₂ toxicity. The information presented in this study provided clues for further research on the interaction between HgCl₂ and selenoproteins, and the possible mechanism of immune organ toxicity induced by HgCl₂.