The Effect of Neuromuscular Electrical Stimulation on the Expression of miRNA in Bone Vessels and Circulating Extracellular Vesicles of Rats with Muscle Deficiency Osteoporosis / 中国运动医学杂志

ABSTRACT

Objective To observe the effect of neuromuscular electrical stimulation on bone angiogene-sis and osteoporosis induced by denervation in sarcopenia osteoporosis rats,and explore the correlation of the miRNA expression level in circulating extracellular vesicles to bone angiogenesis and osteoporo-sis.Methods Ten-week-old male Sprague-Dawley rats were randomly divided into a sham operation control group(con,n=8),a double leg tibial nerve loss group(DD,n=8)and a double leg tibial nerve loss + right leg electrical stimulation group(D+ES,n=8).The tibial nerve of both legs was re-moved in DD and D+ES groups,and one week later the D+ES group received 8-week neuromuscular electrical stimulation.Samples were taken 24 hours after the last stimulation.Trabecular bone parame-ters were detected using micro-CT and its morphology was observed using hematoxylin and eosin(HE)staining.Immunohistochemical staining was used to identify the vascular markers platelet endothe-lial cell adhesion molecule-1(PECAM-1/CD31)and vascular endothelial growth factor A(VEGFA).Moreover,plasma exosomes were extracted and purified,and the vesicles were identified by electron microscopy,nanoparticle tracking analysis(NTA)and Western blotting.Meanwhile,the real time PCR was used to determine the expression of myogenic miR-1,miR-133a,miR-133b and miR-206 in exo-somes.Results(1)Compared with the CON group,the volume and weight of gastrocnemius and sole-us muscles in the DD group reduced significantly(P＜0.001),and the tibial trabecular bone parameters changed pathologically.After 8-week stimulation,compared with the DD group,the volume and weight of gastrocnemius and soleus muscles in D+ES group increased significantly(P＜0.05),and tibial trabecular bone parameters improved significantly.(2)The immunohistochemical staining results indicat-ed that,compared with CON group,the expression of CD31 and VEGFA in the tibia of DD group re-duced significantly,while that of the D+ES group increased significantly compared with DD group.(3)The results of NTA showed that,compared with CON group,the concentration of circulating extra-cellular vesicles in the DD group decreased significantly(P＜0.001),and the expression of miR-1,miR-133a,miR-133b and miR-206 in exosomes increased significantly(P＜0.05,P＜0.01,P＜0.05,P＜0.05 respectively).Compared with the DD group,the concentration of circulating exosomes in D+ES group increased significantly(P＜0.05),and the expression of the above four miRNAs decreased signifi-cantly(P＜0.05 for all).Conclusion Tibial nerve denervation can successfully establish the model of sar-copenia osteoporosis and neuromuscular electrical stimulation significantly relieves such denervation in-duced changes.Moreover,electrical stimulation also significantly increases the concentration of circulat-ing exosomes,and the expression of myogenic miRNAs carried by them,which suggests that the latter may be related to bone angiogenesis and the progression of osteoporosis.