Intercellular calcium wave propagation in linear and circuit-like bone cell networks

Area of Science:

• Biomedical Engineering
• Cell Biology
• Biophysics

Background:

• Bone cells communicate through intercellular signaling.
• Understanding calcium wave propagation is crucial for bone health and mechanotransduction.

Purpose of the Study:

• To elucidate the mechanism of intercellular calcium wave propagation in bone cell networks.
• To compare signal transfer efficiency in different network architectures.

Main Methods:

• Constructed in vitro bone cell networks (linear and looped) using micro-contact printing and self-assembled monolayers.
• Applied mechanical stimulation via nano-indentation to single cells.
• Analyzed intracellular calcium responses and performed pathway-inhibition studies (extracellular ATP hydrolysis, gap junction uncoupling).

Main Results:

• Looped hexagonal networks transferred calcium signals more efficiently than linear chains.
• Extracellular adenosine triphosphate (ATP) diffusion, not gap junctions, was identified as the dominant mediator of mechanically induced intercellular calcium waves.
• Mechanical stimulation required extracellular calcium influx, while ATP-elicited waves depended on endoplasmic reticulum calcium release.

Conclusions:

• Extracellular ATP diffusion is the primary mechanism for mechanically elicited intercellular calcium wave propagation in bone cells.
• Different signaling pathways mediate mechanical stimulation-induced calcium responses versus ATP-elicited calcium waves.