Intracellular free calcium signaling in osteoclasts

Intracellular free calcium signaling in osteoclasts is a fundamental regulatory process that governs the differentiation, activation, and survival of bone-resorbing cells (Takayanagi, 2007, Nature Reviews Immunology). This signaling is primarily initiated by the binding of RANKL to its receptor RANK, which triggers a cascade involving phospholipase C gamma 2 (PLCγ2) and the release of calcium from the endoplasmic reticulum via IP3 receptors (Kuroda et al., 2008, JBC). These initial events lead to characteristic long-lasting calcium oscillations, which are further sustained by store-operated calcium entry (SOCE) through ORAI1 channels (Hwang and Putney, 2011, Cell Calcium). The primary downstream effect of these oscillations is the activation of the phosphatase calcineurin, which dephosphorylates the transcription factor NFATc1, enabling its nuclear translocation and the induction of osteoclast-specific genes (Takayanagi et al., 2002, Nature). Dysregulation of this signaling pathway is central to the pathogenesis of metabolic bone diseases such as osteoporosis and rheumatoid arthritis, where excessive osteoclast activity leads to bone loss (Baron and Kneissel, 2013, Nature Medicine). Therapeutic strategies often target upstream initiators like RANKL (e.g., denosumab) or downstream effectors like calcineurin (e.g., tacrolimus) to modulate this signaling and preserve bone density (Cummings et al., 2009, NEJM).

Other names

Osteoclast calcium oscillationsRANKL-induced calcium signalingCa2+ signaling in osteoclastsCytosolic calcium signaling in osteoclastsCalcium transients in osteoclasts

Inhibition of RANKL-induced signaling, inhibition of calcineurin-mediated NFATc1 activation, and direct inhibition of osteoclast activity and survival.