MyomiR-OsteomiR Crosstalk Induced by Different Modes and Intensities of Exercise Training and its Role in Controlling Osteogenic Differentiation in Old Male Wistar Rats

The crosstalk between skeletal muscles and other tissues such as bones is typically established via the secretion of myokines and myomiRs induced by exercise training (ET). The present study aimed at evaluating the relationship between changes made by different ET modes and intensities in myomiRs, osteomiRs, and other myogenic and osteogenic biomarkers in old male Wistar rats.To this end, a total number of ۵۰ old (۲۳ months of age) male Wistar rats were randomly assigned to four experimental groups, namely, moderate-intensity endurance training (MIET), high-intensity endurance training (HIET), moderate-intensity resistance training (MIRT), high-intensity resistance training (HIRT), and control (CON), each one comprised of ۱۰ subjects.The study findings revealed positive correlations between myomiRs (i.e., miR-۱) and myomiR-۲۰۴a (r=۰.۷۲۵; p=۰.۰۴۲), myomiR-۱, and runt-related transcription factor ۲ (RUNX۲) osteogenic marker (r=۰.۸۶۹; p=۰.۰۲۵) in the HIET group, myomiR-۲۰۶ and peroxisome proliferator-activated receptor gamma (PPARγ) (r=۰.۹۰۸; p=۰.۰۱۲) in the MIRT group, myomiR-۱۳۳a and osteomiR-۱۳۳a (r=۰.۹۷۱; p=۰.۰۰۵) in the MIET group, myomiR-۱۳۳a and osteomiR-۲۰۴a in the MIRT group (r=۰.۹۷۱; p=۰.۰۰۴), and myomiR-۱۳۳a and RUNX۲ gene expression in the HIET group (r=۰.۸۶۱; p=۰.۰۲۷).Interestingly, this study, as the first attempt, found that each ET protocol had no significant effects on the expression of a set of muscle and bone-related miRNAs that could modulate sarcopenia and osteoporosis mechanisms via influencing multiple mRNA and proteins expressions in old animals, which coincided with few significant correlations of gene expressions between skeletal muscle and bone in rats. Moreover, the expression analysis in this study did not group myomiRs and osteomiRs into different clusters according to their expression profiles induced by different ET modes and intensities. However, the study findings hinted at the possible contribution of some osteoblast differentiation markers in attenuating bone dysfunction during different ET modes and intensities, which could possibly happen through some myomiRs regulating gene networks engaged in the transdifferentiation of adipocytes to osteoblasts. Furthermore, it could be concluded that individual myomiRs involved in myoblast and osteoblast differentiation might not be responsible for the response of myogenic and osteogenic targets to physical activity and ET.

کلیدواژه ها:

Exercise Training ، MyomiRs ، OsteomiRs ، Crosstalk ، Osteogenic Differentiation ، Rats