The mechanosensitive ion channel Piezo1 modulates the migration and immune response of microglia

Microglia are the brains resident immune cells, performing surveillance to promote homeostasis and healthy functioning. While chemical signaling in microglia is well-studied, the mechanical cues regulating their function are less well-understood. Here, we investigate the role of the mechanosensitive ion channel Piezo1 in microglia migration, pro-inflammatory cytokine production and stiffness sensing. We demonstrated the functional expression of Piezo1 in microglia and identified genes whose expression was affected by conditional Piezo1 knockout in transgenic mice. Functional assays revealed that Piezo1-deficiency in microglia enhanced migration towards amyloid {beta}-protein, and decreased levels of pro-inflammatory cytokines produced upon stimulation by lipopolysaccharide, both in vitro and in vivo. The phenomenon could be mimicked or reversed using a Piezo1-specific agonist or antagonist. Finally, we also showed that Piezo1 mediated the effect of substrate stiffness-induced migration and cytokine expression. Altogether, we show that Piezo1 is an important molecular mediator for microglia, its activation modulating their migration and immune responses.