The Changes Of Muscle-specific MicroRNAs Induced By An Acute Endurance Eccentric Exercise In Rats

Research objective: Long term regular exercise can not only facilitate morphological adaptations in tissues and organs but also improve health.Eccentric exercise(ECC)has long been the classical model of muscle degeneration and regeneration.Acute high intensity,long duration of ECC will induce delayed onset muscle soreness(DOMS).But in the long term,the muscle damage can be minimized or even can be avoided with gradually increase of frequency and intensity.Therefore,ECC is an ideal model of study biological adaptation,and well planned ECC training might a promising method and strategy training to improve the competitive ability.micro RNAs(mi RNAs)are a family of small non-coding RNAs that may play an important role in regulating physiological processes.As reported,mi RNAs by participating in the transcriptional level of gene regulation to play a role in physiology,generate,proliferation,differentiation and apoptosis in skeletal muscle.We selected seven mi RNAs,which are muscle specific.The aim of this study is to investigate whether circulating mi RNAs and mi RNAs in muscles are affected by eccentric endurance exercise.Besides,the expression level pattern between circulating mi RNAs and mi RNAs in muscles is also important.Research methods: SD wild-type male rats(n=16/group)were randomly assigned to either sedentary or eccentric endurance eccentric exercise(treadmill run,20m/min,90min)group.We demonstrate a dynamic regulation of mi RNA levels following 0h,1h,48 h after eccentric endurance exercise.Also,rest group was not involved in exercise.The rats were sacrificed at different time points,and plasma,gastrocnemius and soleus,quadriceps,heart are needed.We measured 7 selected muscle-specific mi RNAs(mi R-1?mi R-133a?mi R-133b?mi R-206?mi R-208a?mi R-208 b and mi R-499)in plasma and tissues using q RT-PCR technology.Research results: After acute endurance eccentric exercise,some of the muscle specific mi RNAs in plasma had different degrees of response,while in the four kinds of muscle tissue,only the changes of mi R-1 and mi R-133 b in gastrocnemius muscle.At the same time,several myomi Rs in plasma exosome were found to have different responses to exercise.The changes of mi R-133 a levels in plasma and plasma exosome were similar after exercise.Interestingly,the 24 h level of gastrocnemius muscle increased significantly in the mi R-133 b group compared with the control group,but the plasma and plasma exosome showed the opposite trend.Conclusion: We found that mi R-1 in plasma,exosome,gastrocnemius muscle in the same trend.mi R-133 a levels did not change in the four tissues,but increased in both plasma and exosome after eccentric exercise.The changes of mi R-133 b levels in gastrocnemius muscle and plasma showed the opposite trend,but in gastrocnemius muscle and exosome were similar,and reached the highest in 24 h after exercise.These suggest that mi R-1,mi R-133 a and mi R-133 b are potential biomarkers of ECC and play an important role in various biological adaptations caused by ECC.