Inflammatory Signals Enhance Piezo2-Mediated Mechanosensitive Currents

SummaryHeightened nociceptor function caused by inflammatory mediators such as bradykinin (BK) contributes to increased pain sensitivity (hyperalgesia) to noxious mechanical and thermal stimuli. Although it is known that sensitization of the heat transducer TRPV1 largely subserves thermal hyperalgesia, the cellular mechanisms underlying mechanical hyperalgesia have been elusive. The role of the mechanically activated (MA) channel piezo2 (known as FAM38B) present in mammalian sensory neurons is unknown. We test the hypothesis that piezo2 activity is enhanced by BK, an algogenic peptide that induces mechanical hyperalgesia within minutes. Piezo2 current amplitude is increased and inactivation is slowed by bradykinin receptor beta 2 (BDKRB2) activation in heterologous expression systems. Protein kinase A (PKA) and protein kinase C (PKC) agonists enhance piezo2 activity. BDKRB2-mediated effects are abolished by PKA and PKC inhibitors. Finally, piezo2-dependent MA currents in a class of native sensory neurons are enhanced 8-fold by BK via PKA and PKC. Thus, piezo2 sensitization may contribute to PKA- and PKC-mediated mechanical hyperalgesia.

Graphical AbstractFigure optionsDownload as PowerPoint slideHighlights
► Bradykinin (BK) enhances mechanically activated (MA) piezo2 currents
► B2 receptor activation increases piezo2 current amplitude and slows inactivation
► Protein kinase A and protein kinase C inhibition abrogates both BK-induced effects
► MA currents dependent on piezo2 in DRG neurons are similarly modulated by BK