Protective Effect Of ? - Tocotrienol(GT3) On DMD Mouse Muscle Stem Cells

Objectives:?-tocotrienol(GT3)is a natural vitamin E subtype with strong antioxidant capacity.In this study,dystrophin knockout(DMD)mice were used as the model to evaluate the phenotype and function of muscle stem cells,and to analyze the effect and mechanism of GT3 on DMD.Methods:First,we used 40 weeks old C57 BL / 6J male mice(n=6)and DMD male mice(n=6)to observe the basic physiological characteristics of muscle stem cells.Then 40 weeks old C57 BL / 6J male mice and DMD male mice were divided into four groups:WT+PBS(n=6),DMD+PBS(n=6),WT+GT3(n=6)and DMD+GT3(n=6).The morpho-logy and basic pathological changes of muscle cells were observed by HE staining.The expression of Dystrophin,PAX7,PCNA and other related proteins were detected by immunohistochemistry.The oxidative oxygen species(ROS),senescence,apoptosis and DNA damage in muscle stem cells were analyzed by flow cytometry.The expression of apoptotic-related genes was detected by quantitative RT-PCR.Results:1.Compared with the normal control group,DMD knockout mice showed an increase in muscle bundle circumference and a decrease in the numbers of muscle stem cells;2.Compared with the normal control group,DMD knockout mice had an increase in PCNA positive cells in tibia anterior muscle;3.Compared with the normal control group,DMD knockout mice showed an increase in cellular apoptosis,senescence,ROS and DNA damage in muscle stem cells;4.GT3 treatment increased the circumference of tibia anterior muscle of DMD knockout mice and numbers of muscle stem cells of DMD knockout mice.GT3 treatment reduced numbers of PCNA positive cells of tibia anterior muscle of DMDknockout mice;5.GT3 treatment reduced cellular apoptosis,senescence and ROS in muscle stem cells of DMD knockout mice;6.GT3 treatment decreased DNA damage of muscle stem cells in DMD knockout mice.Conclusion:1.Compared with wild type mice of the same age,numbers of muscle stem cells in DMD mice was decreased and the proliferation speed was accelerated;2.Compared with wild type mice,the muscle stem cells in DMD mice have higher ROS level,senescence,apoptosis and DNA damage.3.GT3 treatment increases the number of muscle stem cells in DMD mice and reduces their proliferation rate;4.GT3 treatment reduces the ROS production,apoptosis and DNA damage of muscle stem cells in DMD mice.