Piezo channels for skeletal development and homeostasis: Insights from mouse genetic models.

Piezo1 and Piezo2 are recently discovered mechanosensory ion channels. Piezo channels transduce mechanical stimulation into cellular signaling in a variety of tissues and organ systems. The functional roles of Piezo1 and Piezo2 have been revealed in both developmental and physiological scenarios by using mouse genetic models. Mechanotransduction by Piezo1 channels regulates osteoblast/osteocyte activity and, thus, strengthens the skeleton enabling it to adapt to a wide range of mechanical loadings. Deletion of the Piezo1 gene in the developing skeleton causes bone malformations that lead to spontaneous bone fractures, while inactivity of Piezo1 in adulthood results in osteoporosis. Furthermore, Piezo2 channels in sensory neurons might provide another route of skeletal regulation. Piezo channels also regulate the proliferation and differentiation of various types of stem cells. PIEZO1 and PIEZO2 mutations and channel malfunctions have been implicated in an increasing number of human diseases, and PIEZO channels are currently emerging as potential targets for disease treatment. This review summarizes the important findings of Piezo channels for skeletal development and homeostasis using the mouse genetic model system.