Effects Of Muscle-Specific MicroRNAs In The Cycling And Different Tissues Of Mice Overtraining Model

Research objective: Overtraining has many effects on the physiological state of the body,which affects exercise capacity,and the physiological state of skeletal muscle plays a vital role in exercise capacity.The purpose of this study was to use microRNAs(miRNAs)as an emerging biomarker to investigate whether muscle-specific miRNAs can be used as over-training biomarkers;Are there differences in the expression of miRNAs in skeletal muscle and myocardium by muscle-specific miRNAs? The accumulation of muscle-specific miRNAs caused by long-term training will play a biological regulatory role in the metabolism of the main organs(liver),mediating the physiological process of overtraining.Research methods: C57BL/6J rats(n=15/group,23.88±0.94 g)were randomly divided into control group(Control training,CON),exercise group(Normal training,NT)and overtraining group(Overtraining,OT).The CON did not participate in the exercise.The NT performed 60% EV,60 min for 4 weeks;After 5-8 weeks in the NT performed 60% EV,60 min,and 14% slope.The OT performed 60% EV,60 min with no slpre for 4 weeks;In the fifth week,the OT performed a downslope of 14%,a speed of 60% EV,and a duration of 60minutes;In the sixth week,the OT performed a downslope of 14%,a speed of70% EV,and a duration of 60 minutes.In the seventh week,the downhill was14%,the speed was 75% EV,and the duration was 75 minutes.In the eighth week,the training was performed twice a day.The mice were anesthetized,and1.5 ml of blood was taken from the eyeball,followed by the gastrocnemius,myocardium and liver.We measured 7 selected muscle-specific miRNAs(miR-1,miR-133 a,miR-133 b,miR-206,miR-208 a,miR-208 b and miR-499)in Serum,muscle and liver using qRT-PCR technology.Research results: In serum,miR-133 a,miR-133 b and miR-208 a decreased in both exercise groups,but decreased significantly in the OT group;miR-1 and miR-133 a levels in the gastrocnemius decreased,but the NT group decreased more;there was no significant change in miRNAs in the liver;both miR-133 a and miR-133 b increased in the heart,but miR-499 decreased.Conclusion: 1.There were significant changes in serum miR-133 a,miR-133 b and miR-208 a.All of the above three miRNAs are tested at rest and are the result of long-term adaptation to overtraining.Physiological phenomena involved in overtraining.Can potentially be used as a potential biomarker for monitoring overtraining,as a normal value reference interval.2.The changes in miR-1 and miR-133 a in skeletal muscle after 8 weeks of overtraining are long-term cumulative results that participate in both the physiological phenomenon of overtraining,and can also serve as a reference range for normal values.However,there is an opposite trend in the heart,and the specific reasons remain to be further studied.3.The above seven miRNAs did not detect significant differences in the liver,because of long-term training and the metabolic system tends to be stable in metabolic tissue(in the liver).