Piezo1 plays a role in optic nerve head astrocyte reactivity

Piezo1 (also known as Fam38A) is a mechanosensing channel required for mechanotransduction in various cell types. In astrocytes, Piezo1 activation is associated with the pathogenesis of central nervous system neurodegeneration. Expression of Piezo1 has been detected in mouse optic nerve head astrocytes, however, the functional role of Piezo1 has not been identified. In this study, we investigated the role of Piezo1 in optic nerve head astrocyte reactivity. Primary mouse optic nerve head astrocytes were cultured and subjected to mechanical stretch. The expression level of Piezo1 was determined by quantitative PCR and immunocytochemistry staining. Astrocytes were further treated with Yoda1, a specific Piezo1 agonist. The intracellular calcium concentration and expression of F-actin and fibronectin were determined in Yoda1 treated cells. We found that mechanical stretch activated Piezo1 in optic nerve head astrocytes. Yoda1 induced robust Ca²⁺ responses in a dose dependent manner. In addition, Yoda1 treated cells showed a redistribution of F-actin cytoskeleton and an increased expression of fibronectin which indicated astrocyte reactivity. Our results suggest that Piezo1 responses to mechanical stimulation and plays a role in astrocyte reactivity. This study provides new insights into optic nerve head astrocyte mechanotransduction.