Osteocyte calcium signaling response to bone matrix deformation

Area of Science:

• Biomedical Engineering
• Cell Biology
• Bone Physiology

Background:

• Osteocytes, embedded in bone matrix, are crucial for mechanosensing and adaptive bone remodeling.
• Previous in vitro studies identified various mechanical stimuli affecting osteocyte function, but in-matrix responses remain unclear.

Purpose of the Study:

• To quantitatively assess osteocyte calcium signaling in response to mechanical deformation within the bone matrix.
• To develop and validate a novel experimental system for applying controlled mechanical stimuli to osteocytes in their native environment.

Main Methods:

• A novel microscope-stage system was engineered to apply in-plane shear deformation to embryonic chick calvariae bone fragments using glass microneedles.
• Image correlation methods quantified matrix and cell deformation using differential interference contrast and fluorescent imaging.
• Ratiometric imaging captured cellular calcium transients in response to applied mechanical stimuli.

Main Results:

• The developed system successfully applied deformation to the bone matrix and osteocytes under microscopic observation without compromising image quality.
• The system demonstrated the ability to quantitatively evaluate cellular and matrix deformation and simultaneously monitor calcium signaling.

Conclusions:

• The novel experimental system provides a robust platform for investigating osteocyte mechanosensing mechanisms within the bone matrix.
• Further studies can utilize this system to explore rapid biochemical signaling and intercellular communication triggered by matrix deformation.