Rho-kinase negatively regulates thyroid hormone-stimulated osteocalcin synthesis in osteoblasts

► T3 induces the phosphorylation of MYPT-1, a Rho-kinase substrate in osteoblasts. ▶ Rho-kinase inhibitors enhance T3-stimulated osteocalcin release. ► T3-stimulated osteocalcin release is amplified in Rho-knocked down osteoblasts. ► Rho-kinase inhibitors increase the mRNA expression of osteocalcin induced by T3.