ACTIVATION OFGLUCOSE TRANSPORTER 1 (GLUT1) IS REQUIRED FOR THE MECHANICAL STRESS-INDUCED BONE FORMATIONVIA THE SIGNAL TRANSDUCTION NETWORK BETWEEN THE CELLULAR ENERGY SENSOR, NAD+-DEPENDENT DEACETYLASE (SIRTUIN1), AND THE OSTEOGENIC TRANSCRIPTION FACTOR, RUNT-RELATED TRANSCRIPTION FACTOR 2 (RUNX2), IN OSTEOBLASTS.

Abstract

Purpose: Mechanical stress is a critically-important factor affecting bone tissue homeostasis. To determine whether physiologic mechanical loading affects the expression of factors regulating energy metabolism and transcription factors controlling osteoblast differentiation, we focused on the interaction between glucose uptake via glucose transporter 1 (Glut1) and the cellular energy sensor sirtuin 1 (SIRT1) in osteoblast energy metabolism, since it has been recognized that SIRT1, an NAD+-dependent deacetylase, may function as a master regulator of mechanical stress response as well as cellular energy metabolism (glucose metabolism).