(725c) A Multimodally Regulated Microenvironment for Mechanotransduction Studies of Organ Development

The emergence of diseases is known to depend on both genetic and biomechanical factors. However, much work remains to be done to define the complex regulatory interactions responsive to environmental stimuli. More specifically, the impact of exogenous forces, such as mechanical compression, on the regulation of these signaling cascades, which effect basic cellular processes such as proliferation and apoptosis, remains unresolved. Although the mechanisms of regulation are unknown, mounting experimental evidence has increasingly implicated mechanical forces in the regulation of cell cycle, cell survival and cellâ??cell communication. However, probing these relationships experimentally remains problematic, owing to the unique challenges involved in mechanically manipulating tissues both in and ex vivo. Here we describe the fabrication and implementation of a scalable microfluidic culture chip (the Regulated Epithelial Microenvironment Chip) for studying the impact of exogenous forces on development and gene expression in organ cultures. The chip consists of individually addressable culture chambers. Each chamber allows control over the chemical perfusion of culture media, while the precise application of compressive forces exerted on the disc is achieved via a pneumatically operated membrane on the chamberâ??s ceiling. Enabled by the REM-Chip, we demonstrate that Ca²⁺ signaling is inhibited during mechanical compression, but once compression is removed a Ca²⁺ wave cascades throughout the disc. This response is dependent on the presence of specific serum conditions indicating synergy between chemical and mechanical factors. Further, specific pharmacological or genetic manipulation of specific morphogen pathways modulates the frequency and amplitudes of long-distance Ca²⁺ waves. The REM-Chip enables quantitative studies into cross-talk between genetic and environmental factors at the tissue and organ scale.