Exercise Preconditioning Mediates The Effects Of MiR146a On Inflammatory Factors In Cerebral Ischemia-reperfusion Rats Via Exosomes

Objective: to observe the effect of 8-week exercise preconditioning on the expression of miR146 a in rats,and to explore the effect of miR146 a expression on inflammatory factors after cerebral ischemia-reperfusion and the relationship among related factors.Methods: 60 healthy male SD rats were randomly divided into non-exercise group and exercise group.The exercise group was given adaptive exercise for one week.One week later,the non-exercise group was divided into sham operation group(CC,n=15)and model group(ZM,n=15),and the exercise group was divided into exercise group(E,n=15)and exercise model group(PM,n=15).The rats in E group and PM group did treadmill exercise for 8 weeks,6 days a week.After 1 week of adaptive feeding,the rats in the CC group and the ZM group were given the same water and food as the exercise group to control their body weight.The body weight of rats in each group was measured every day.After 8 weeks,the MCAO model was made in ZM and PM groups,and the neurobehavioral score was performed 24 hours after modeling.CC group and E group were fully exposed to the common carotid artery without modeling.After 24 hours of modeling,the cerebral infarction volume was measured by TTC staining,the number of Nissl bodies in the brain was observed by Nissl staining,the content of miR146 a in brain and plasma was determined by QT-PCR,and the protein expression levels of TRAF6,TNF-? and NF-?B in brain were determined by WB.Results:(1)after 8 weeks of exercise,the body weight of rats in each group was basically the same.The neurological score in ZM group and PM group was significantly higher than that in CC group and E group.TTC staining showed that the infarct area appeared in ZM combined with PM group,and Nissl staining showed that the number of hippocampal corpuscles in ZM group and PM group was less than that in CC group and E group.(2)compared with CC group,the expression of miR146 a in brain and plasma was less in ZM group and PM group,and it was more in PM group than in ZM group.Compared with CC group,the expression of miR146 a in brain and plasma was higher in E group.(3)Compared with CC group,the protein expressions of TRAF6,TNF-? and NF-?B in ZM group and PM group were higher,and the expression of TRAF6,TNF-? and NF-?B in PM group was less than that in ZM group.Conclusion:(1)8 weeks of exercise preconditioning can increase the expression of miR146 a in brain and body.(2)8-week exercise preconditioning can reduce the expression of TRAF6,NF-?B and TNF-? in ischemic stroke,reduce the brain damage,have a certain protective effect on the brain,and is related to the decrease of TNF-? expression.(3)There may be a correlation among miR146 a,TRAF6,NF-?B and TNF-? in the case of ischemic stroke caused by inflammation.