Mutually beneficial crosstalk between muscle cells and osteocytes

Abstract

Integrative biological approaches have led to the discovery of new physiological roles for bone and skeletal muscle that might have implications for our understanding of osteoporosis and sarcopenia. We recently investigated the crosstalk between bone and muscle cells by testing the effects of conditioned media (CM) from MLO-Y4 osteocytes and we found that MLO-Y4 CM induced myogenic differentiation of C2C12 myoblasts along with changes in calcium handling and gene expression suggesting activation of the MURF-NF-kB pathway. Here, we tested the response of MLO-Y4 osteocytes subjected to fluid flow shear stress in the presence of CM from C2C12 myotubes. We found that C2C12 myotubes CM modulate the expression of genes related to calcium homeostasis, heat shock response, apoptosis, and apparently enhancement of osteocytes differentiation program. These data along with our recent ASBMR abstract showing that CM from C2C12 myotubes enhanced the effects of shear stress on MLO-Y4 release of PGE2, activation of Akt and translocation of β-catenin indicate that molecular signaling between muscle and bone has the potential to be mutually beneficial. Support: NIH RC2 AR058962 and Missouri Life Sciences Research Board.