Poster V12 - Reverse-engineering mechanobiology: Piezo regulates epithelial topology and promotes precision in organ size control

Introduction: Mechanosensitive Piezo channels have been implicated in the progression of multiple types of cancer. Piezo, a mechanosensitive calcium channel, promotes cell division by activating ERK signaling or can activate Rho signaling to mediate cell extrusion and cell death. However, the systems-level functions of Piezo in organogenesis and tissue homeostasis remain poorly understood. To reverse-engineer how Piezo impacts cellular processes in multicellular systems, we focus on a highly accessible model system of organ size control, the Drosophila wing imaginal disc. Here, we demonstrate that Piezo controls epithelial cell topology to ensure precise organ growth by integrating methods, including live imaging experiments coupled with pharmacological and genetic perturbations and computational modeling. Our findings demonstrate that Piezo promotes robustness in regulating epithelial topology and is necessary for maintaining precise organ size control. These insights into the multiscale roles of Piezo lay the foundation for identifying new therapeutic strategies crucial for cancer engineering.

Materials and

Methods: We used the GAL4-UAS system to express RNAi to knockdown (KD) Piezo or overexpress Piezo in the Drosophila wing imaginal disc, a powerful in vivo model system for reverse engineering mechanobiology and testing new therapeutic modalities. We also characterized the complete knockout (KO) of Piezo. A hybrid polyethylene terephthalate laminate (PETL) microfluidic device6 was used in combination with confocal microscopy to ensure extended periods of stable ex vivo imaging and allow the addition of a constant flow of media. Immunohistochemistry was utilized for systematic characterization of cell processes and tissue structure was pursued through immunohistochemistry. Additional analysis included laser ablation and computational modeling of organ growth.

Results, Conclusions, and Discussions: This work demonstrates how Piezo channels influence organ size and the structure of epithelia. We posit that Piezo channels act as feedback controllers to regulate the cellular topology of epithelial tissues and epithelial packing through the combined control of downstream processes such as proliferation, apoptosis, and cytoskeletal regulation. Thus, targeting the strength of feedback through Piezo may be an attractive modality for pursuing optogenetics and cancer therapeutics.

Acknowledgements (Optional): Thanks to Dr. Sara Cole from Notre Dame Integrated Imaging Facility for helping with imaging. The work was supported by NIH 1R35GM124935-01, NSF CBET-2225601, and EMBRIO Institute, NSF DBI contract #2120200.