Selenium Deficiency Mainly Influences Antioxidant Selenoproteins Expression in Broiler Immune Organs

Selenoprotein has many functions in chicken, and the expression of selenoproteins is closely associated with the selenium (Se) level. However, little is known about the expression patterns of selenoproteins in chicken immune organs. Here, we investigated the effect of dietary Se deficiency on the expressions of 23 selenoproteins in broiler immune organs. In this study, 150 broilers were randomly divided into two groups (75 chickens per group). The chickens were maintained either on a diet supplemented with Se through the addition of 0.2 mg/kg of Se (C group) via sodium selenite or on a Se-deficient granulated diet (L group) until the broilers exhibited an onset of exudative diathesis (ED). Following euthanasia, the samples from the immune tissues (including the spleen, thymus, and bursa of Fabricius) were quickly collected, and the messenger RNA (mRNA) expression levels of 23 selenoproteins were examined by real-time quantitative PCR and analyzed using principal component analysis. The results showed that Se deficiency decreased the mRNA levels of 23 selenoproteins in the thymus, spleen, and bursa of the Fabricius tissues of broiler chickens. Furthermore, we found that among 23 selenoproteins, the mRNA levels of Dio1 in the thymus, Txnrd2 in the spleen, and Txnrd3 in the bursa of Fabricius decreased significantly (90.9 %, 83.3 %, and 96.8 %, respectively). In addition, the principal component analysis (PCA) results suggested that Se deficiency mainly influenced the expression of antioxidative selenoproteins, especially glutathione peroxidases (Gpxs), thioredoxin reductases (Txnrds), and iodothyronine deiodinases (Dios) in chicken immune organs. The results of this study are valuable for understanding the relevance of selenoprotein activity in vivo.