PTH Promotes Bone Anabolism by Stimulating Aerobic Glycolysis via IGF Signaling

Teriparatide, a recombinant peptide corresponding to amino acids 1-34 of human parathyroid hormone (PTH), has been an effective bone anabolic drug for over a decade. However, the mechanism whereby PTH stimulates bone formation remains incompletely understood. Here we report that in cultures of osteoblast-lineage cells, PTH stimulates glucose consumption and lactate production in the presence of oxygen, a hallmark of aerobic glycolysis, also known as Warburg effect. Experiments with radioactively labeled glucose demonstrate that PTH suppresses glucose entry into the tricarboxylic acid cycle (TCA cycle). Mechanistically, the increase in aerobic glycolysis is secondary to insulin-like growth factor (Igf) signaling induced by PTH, whereas the metabolic effect of Igf is dependent on activation of mammalian target of rapamycin complex 2 (mTORC2). Importantly, pharmacological perturbation of glycolysis suppresses the bone anabolic effect of intermittent PTH in the mouse. Thus, stimulation of aerobic glycolysis via Igf signaling contributes to bone anabolism in response to PTH. (c) 2015 American Society for Bone and Mineral Research.