Selenium (Se) Homeostasis in Chicken Central Nervous System Involves Selenoprotein Expression from Insufficient to Excess Se

Abstract

Selenium (Se) incorporated in selenoproteins as selenocysteine and supports various important cellular and organismal functions. When Se deficient, brain present the first priority grade to get it. It becomes a homeostasis of Se content. We recently reported that O‐Phosphoseryl‐tRNA: selenocysteinyl‐tRNA synthase (SepSecS) plays an important role in Se homeostasis regulation in the avian brain (PloS One 7:e35761 (2012)). To better understand the relationship of Se homeostasis and selenoprotein expression in chicken central nervous system (CNS), day‐old HyLine White chickens were fed a low Se diet (Se‐L, 0.028 mg/g) supplemented with 4 levels of dietary Se (0 to 5.0 mg Se/kg) as Na2SeO3 for 8 wk. Then chickens were dissected for getting the CNS, which included cerebral contex, cerebellum, thalamus, bulbus cinereus and marrow. Se content in CNS was measured. The expression of selenoproteome which have 24 selenoproteins were detected by the qRT‐PCR array. Se homeostasis was observed during changed the content of Se in chicken CNS from insufficient to excess Se, especially in cerebral contex and bulbus cinereus. In cerebellum, the expression of SePP1 had augmented when Se content was abundant. It implied that SePP1 was the main Se transporters. In bulbus cinereus, the selenoprotein had increased obviously as the content of Se was 3.0 mg/kg. Furthermore, at the 5.0 mg/kg Se, there was a special increase about the selenoprotein expression in the marrow. The distribution of Se in chicken CNS is very notable. The expression of selenoproteins has a hierarch while changing Se content, and Selt, Selk, Selw, Selu, Gpx3, Gpx4, Sepp1, Selo, Sel15, Seln, Gpx2 and Sepp2 take more necessary function in the chicken CNS. In summary, hierarchy of regulated selenoprotein expression makes an important role of CNS Se metabolism and transport in avian.Support or Funding InformationChina New Century Excellent Talents in University (NECT‐1207‐02), China Program for New Century Excellent Talents In Heilongjiang Provincial University (1252‐NCET‐009), Doctor Initial Funding of Northeast Agricultural University (2012RBC52), Research Special funds for Scientific Innovation Talents of Haerbin (2012RFQXN006) and Science Foundation of the Education Department of Heilongjiang Province (12511031).