Generation of Piezo1-CreER transgenic mice for visualization and lineage tracing of mechanical force responsive cells in vivo.

Cells and tissues are exposed to a wide range of mechanical stimuli during development, tissue homeostasis, repair, and regeneration. Over the past few decades, mechanosensitive ion channels (MSCs), as force-sensing integral membrane proteins, have attracted great attention with regard to their structural dynamics and mechanics at the molecular level and functions in various cells. Piezo-type MSC component 1 (Piezo1) is a newly discovered MSC; it is inherently mechanosensitive. However, which type of cells express Piezo1 in vivo remains unclear. To detect and trace Piezo1-expressing cells, we generated and characterized a novel tamoxifen-inducible Cre knock-in mouse line, Piezo1-CreER, which expresses CreER recombinase under the control of the endogenous Piezo1 promoter. Using this genetic tool, we detected the expression of Piezo1 in various cell types at the embryonic, neonatal, and adult stages. Our data showed that Piezo1 was highly expressed in endothelial cells in all the three stages, while the Piezo1 expression in epithelial cells was dynamic during development and growth. In summary, we established a new genetic tool, Piezo1-CreER, to study Piezo1-expressing cells in vivo during development, injury response, and tissue repair and regeneration.