Exosomes from C2C12 myoblasts enhance osteogenic differentiation of MC3T3-E1 pre-osteoblasts by delivering miR-27a-3p.

Many regulators have been identified to participate in the cross-talk between muscle and bone, however, most previous studies focus on secreting proteins. In this study, we demonstrated that exosomes from myoblasts C2C12 can promote pre-osteoblasts MC3T3-E1 differentiation to osteoblasts. We revealed that the effect of C2C12 exosomes depended on its miR-27a-3p component, they can increase miR-27a-3p level in the recipient cells, and decrease its direct target adenomatous polyposis coli (APC) expression, thus activating β-catenin pathway. Furthermore, C2C12 exosomes failed to exert above effects when miR-27a-3p was deprived. These findings indicates exosomal microRNAs can be regarded as a novel type of "myokines" with osteogenesis promoting potential, which would broad our understanding of the muscle-bone interaction under physiological and pathological conditions.