Effects of microgravity on skeletal muscle glucogen metabolism through m6A modification
Long-term space flight will lead to skeletal muscle atrophy,and the disorder of glucose metabolism may be one of the important reasons.N6-methyladenosine(m6A)is the most common and conserved messenger RNA modification in eukaryotes and is often involved in the regulation of key gene expression.This study aimed to explore the effect of microgravity on glycogen metabolism in muscle cells and the correlation between m6A modification induced by microgravity and glycogen metabolity-related enzyme expression.The content of glycogen in skeletal muscle cells was detected by anthrone method.The glucose uptake of skeletal muscle cells labeled by fluorescent D-glucose analogs[2-N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino-2-deoxyglucose,2-NBDG]was detected by flow cytometry.The changes in m6A modification of messenger RNA were detected by Dot Blot,and expressions of glycogen metabolism related enzymes and m6A modification related enzymes were detected by qPCR and Western blot.The level of m6A modification of glycogen metabolism related enzymes in muscle cells was detected by methylated RNA immunoprecipita-tion(meRIP).The correlation between glycogen metabolism related enzymes and m6A modification related enzymes in clinical and animal experiments was analyzed using GEO database.The results showed that under simulated microgravity conditions,the glycogen content of mouse myoblasts C2C12 decreased,the glucose uptake capacity decreased,and the expression of glycogen metabolism related enzyme:glycogen synthase kinase-3a(Gsk3a),glycogen phosphorylase-muscle(Pygm),glycogen phosphorylase-brain(Pygb)and phosphoglucomutase 3(Pgm3)were changed.The expression of m6A modified related enzyme methyltransferase-like protein 3(Mettl3)is down-regulated,and the mRNA of Pgm3 and Gsk3a was modified by m6A.The results of this study suggest that microgravity may change the m6A modification of glycogen metabolism related enzymes through m6A modification related enzyme expression change,thus cause glycogen content changes in skeletal muscle and affect skeletal muscle cell metabolic homeostasis.This study preliminarily suggests the causes of energy metabolism disorder,muscle atrophy and functional decline of muscle cells under microgravity condition at molecular level,and provided a new idea for improving energy supply level of skeletal muscle cells,slowing muscle atrophy and improving muscle group efficiency under microgravity environment.
万方数据
维普
