Figure 1.

From the perspective of energy metabolism, over-differentiation of osteoclasts leads to osteoporosis. Multifactorial regulation of osteoclastogenesis is accompanied by an increased mitochondrial number and increased cellular respiration and ATP production. The orange line represents a positive feedback mechanism. ATP, adenosine triphosphate; ERR, estrogen receptor-associated receptors; M-CSF, macrophage colony stimulating factor; OXPHOS, oxidative phosphorylation; PGC-1β, peroxisome proliferator-activated receptor gamma coactivator-1β; RANK, receptor activator of NF-kB; RANKL, receptor activator of nuclear factor kappa-B ligand; ROS, reactive oxygen species; TCA cycle, tricarboxylic acid cycle.