The Effect Of Se On Differentiation Of Chicken Embryonic Myoblasts And Chicken Skeletal Muscle Inflanmation Factors

Selenium (Se) is an essential trace element for human and animal and involved in manyaspects of health, playing a major role in maintaining the common physiological functions. Seplays important roles in muscle metabolism. It was thought that muscle disease had a closelyrelatioship with the deficiency of selenium, and causes the degeneration of cardiac and skeletalmuscle characterized by the presence of calcium deposits, skeletal muscle myodegeneration,vascular lesions, and hemorrhages. The biological functions of Se are mainly elicited throughselenoprotein proteins. Selenoprotein W (SelW), one member of the selenoprotein family, is highlyexpressed in cardiac and skeletal muscle, and plays an important role in maintaining the commonphysiological functions of skeletal muscle. As far as the present studies, the researches about SelWare mainly carried out in mammalian. However, there was little report that showed the associationwith SelW and selenium dificiency myopathy, especially the research of Se in the regulation ofgene expression and pathogenesis in the selenium dificiency myopathy are seldom carried out inpoultry. In this study, on the basis of Se deficiency chick model and primary culture of chickenembryo, for investigating the effects of Se on the morphology change of chicken embryonicmyoblasts at different Se concentrations in medium (10-9,10-8,10-7,10-6,10-5M) for12,24,48,and72h; then the mRNA levels of SelW and myogenic regulatory factors (MRFs): Myf-5,Myogenin, MRF4in myoblasts were determined；and the correlation between SelW mRNAexpression and MRF mRNA expression was assessed; and the further investigations of the mRNAexpression of SelW, inflammation factors (NF-κB, TNF-α, iNOS, COX-2, PTGES) in chickenswing muscle, pectorals, thigh muscle at15,25,35,45and55days old, and the correlationbetween SelW mRNA expression and inflammation related genes by using morphologyobservation, quantitative RT-PCR technique and SPSS statistical software. The results wereshowed as follows:1. The morphology change assay of chicken embryonic myoblasts showed that the optimal Se(10-7M) promotes the differentiation of cells; but excessive Se supplement (105M) inhibited thedifferentiation of chicken embryo myoblasts and significantly decreased cell viability. These resultsdemonstrated that Se plays a role in the process of differentiation of chicken myoblasts. In contrast, excessive high concentration of Se presented a toxic function.2. The greatest increase of SelW mRNA expression was observed in the group of107M Secontent at different time points, which indicated that the optimal content for the expression of SelWmRNA in chicken embryonic myoblasts was107M. Oppositely excessive high concentration ofSe (105M) inhibited the expression of SelW mRNA.3. The results revealed that the mRNA levels of the three MRFs: Myf-5, Myogenin and MRF4first increased and then tended to decrease after Se was supplemented in the medium, the greatestincrease of MRFs mRNA expression was observed in the group of107M and10-8M Se contents,whereas excessive Se (10-5M) inhibited their expression, which indicated that an optimalconcentration of Se could promote the expression of the three MRFs in chicken embryonicmyoblasts, and the results were consistent with the results of the morphology assay. Myf-5,Myogenin and MRF4mRNA levels were significantly correlated with SelW mRNA. We thushypothesize that SelW may play a role in the process of differentiation of chicken embryonicmyoblasts.4. Se deficiency can reduce the mRNA expression of SelW in Chicken wing, pectorals, andthigh muscles. And chicken thigh muscle was more sensitive to Se deficiency among thesemuscles.5. Se deficiency increased the mRNA expression of inflammation related genes (NF-κB,TNF-α, iNOS, COX-2and PTGES) mRNA levels in chickens’ skeletal muscles at different dayspoints, which demonstrated that these inflammation related genes involve in the occurrence anddevelopment in the inflammatory process of chicken skeletal muscle system. The negativerelativity of inflammation related genes and SelW indicated that SelW may play a role in theregulation of inflammation reaction in Se deficiency myopathy.