(20c) Microfluidic Platform to Decode Mechanotransduction Mechanisms in Developing Organs

Mechanical forces are critical but poorly understood inputs into organ development and wound healing. Calcium ions are critical second messengers in cells for integrating environmental and mechanical cues, but the regulation of calcium signaling is poorly understood in developing epithelial tissues. Here we report a chip-based regulated environment for micro-organs (REM-Chip) that enables systematic investigations of the crosstalk between an organ’s mechanical stress environment and biochemical signaling under genetic and chemical perturbations with concurrent live imaging. This method enabled us to define the essential conditions for generating organ-scale intercellular calcium waves in Drosophila wing discs that are also observed in vivo during organ development. We discovered that mechanically induced intercellular Ca²⁺ waves require fly extract growth serum as a chemical stimulus. Using the REM-Chip, we demonstrate the release of mechanical compression rather than the initial application is sufficient to initiate intercellular Ca²⁺ waves. The Ca²⁺ response depends on the pre-stress intercellular Ca²⁺ activity and not on the magnitude or duration of mechanical stimulation applied. Mechanically induced intercellular calcium waves rely on IP₃R mediated calcium induced calcium release and propagation through gap junctions. Thus, intercellular calcium waves in developing epithelial tissues may be a consequence of stress dissipation observed during organ growth and wound healing.