Exercise Regulate Lysosome Function By Activate SIRT1/TFEB Pathway

Aim:To study the effect of long-term exercise training on autophagy-lysosomal function in mouse brain and explore its molecular mechanism by establishing short-term exercise.Methods:The mice of long-term exercise were trained on a treadmill 60min/day and5 days/week for 8 weeks.First,the effect of long-term exercise on lysosomal function of cerebral cortex,striatum and hippocampus were valued.The autophagy/lysosomal associated proteins level was determined by Western blot.The autophagy vacuoles and lysosome were observed through electron microscope.TFEB nuclear translocation was determined by Western blot and Immunofluorescence.Gene transcriptional analysis of the TFEB-regulating genes was determined by quantitative PCR(qPCR).Later,the molecular mechanism of exercise on lysosome of cerebral cortex was studied.Phosphorylation of the downstream proteins of the mTORC1 and AMPK pathway was analyzed by Western blot.The activity of SIRT1 was analyzed by the acetylation level of Histone H3 and SIRT1/Sir2fluorometric assay kit.The effects of SIRT1 on TFEB nuclear translocation and its regulating gene transcriptions were investigated with the treatment of resveratrol,the SIRT1 activator,or Ex527,the SIRT1 inhibitor.Results:The level of autophagosomes-associated protein LC3?and lysosomal-associated membrane protein LAMP1 were significantly higher in exercise training group than the control group both in cerebral cortex and striatum.The mature type of lysosomal protease Cathepsin D and Cathepsin L increased in the Exe group as well.In the meanwhile,Transcription factor EB,a master transcriptional regulator of lysosomal biogenesis and autophagy,increased in the exercise training group and it was prone to translocate into the nucleus.All the data showed that exercise could enhance the autophagy-lysosomal function.Exercise activated the AMPK signaling transduction.p-AMPK?p-ACC?p-ULK1(Ser555)increased to the max at 6h after exercise.Exercise also increased the NAD~+level and enhanced the deacetylation function of SIRT1.Resveratrol,the stimulator of SIRT1,enhanced the nuclear translocation of TFEB and increased the gene transcription of TFEB regulating genes;Ex527,the inhibitor of SITR1,had little effect on the location of TFEB,but it inhibited the gene transcription regulation of TFEB.Conclusion:Long-term exercise training increases the autophagy level and the lysosomal function of cerebral cortex,striatum and hippocampus.Exercise enhances the nuclear translocation of TFEB,activates AMPK signaling transduction,increases the deacetylation function of SIRT1,and enhances the gene regulating effect of TFEB on the autophagy/lysosomal biogenesis and their functions.