Intercellular Calcium Wave Propagation in Linear and Circuit-Like Bone Cell Networks

Intracellular calcium ([Ca²⁺]_i) transients in response to mechanical stimulation can be propagated to neighboring cells in bone cell networks, which provides an essential mechanism for cell-cell communication in bone. Transfer of intracellular second messengers (e.g., IP₃ and Ca²⁺) through gap junction pores and the diffusion of extracellular ATP to activate membrane receptors have long been conjectured as the two major pathways for intercellular Ca²⁺ wave propagation [1]. In this study, by comparing the calcium wave in open-end linear and looped circuit-like cell chains, the roles of gap junction intercellular communication (GJIC) and extracellular ATP diffusion in calcium wave propagation in bone cell networks were examined. The results were further confirmed with pathway-inhibitor studies performed on linear cell chains.