Inhibition of Piezo1 Alleviates Ischemia-Reperfusion-Induced Acute Kidney Injury by Suppressing Inflammation

Background: Inflammation is a major contributor to acute kidney injury (AKI) induced by ischemia/reperfusion (I/R), the potential mechanism is still unclear. Here we demonstrated that Piezo1, a mechanosensitive cation channel, aggravated I/R-induced AKI and inflammation. Methods: Bioinformatic analysis was used to screen differentially expressed genes and pathways. Pharmacological inhibition by GsMTx4 and conditional knockout of proximal tubular Piezo1 (Pepck-Cre+/Piezo1fl/fl) were performed in mice to identify the role of Piezo1 in renal I/R. NLRP3 knockout (Nlrp3-/-) mice were used to examine whether Piezo1 mediates NLRP3 inflammasome activation and subsequent inflammation after renal I/R. Primary mouse proximal tubular cells (mPTCs) from Pepck-Cre+/Piezo1fl/fl and Nlrp3-/- mice as well as human HK2 cells were subjected to hypoxia/reoxygenation (H/R) to explore the association between Piezo1 and NLRP3. Virtual screening identified a Piezo1 inhibitor and its renoprotective efficacy was validated. Results: Piezo1 was highly expressed in renal cortex of I/R mice, which was associated with inflammatory pathways. Inhibition of Piezo1 with GsMTx4 and conditional knockout of proximal tubular Piezo1 markedly ameliorated I/R–induced AKI in mice, accompanied by NLRP3 inflammasome inhibition and decreased production of inflammatory factor IL-1β. NLRP3 knockout ameliorated I/R or Yoda1-induced renal injury and inflammation. In HK2 cells, H/R markedly induced Piezo1 expression and inflammatory responses, which were greatly prevented by GsMTx4 or silence of Piezo1. In mPTCs, H/R or Yoda1 induced Piezo1 activation and inflammatory responses that were markedly prevented by NLRP3 knockout. Mechanistically, inhibition of Piezo1 ameliorates I/R-induced AKI via PI3K/AKT-NLRP3-IL1β pathway, and IL1β promoted the re-activation of Piezo1 via IL1R1-p38-ATF2 signalling or the interaction between IL1R1-Piezo1, forming a pro-inflammatory feedback loop. Baicalin, a flavonoid, was found as a potential inhibitor of Piezo1 by virtual screening and significantly mitigated H/R-induced HK2 cell injury and I/R-induced AKI. Conclusion: Piezo1 is involved in I/R-induced AKI likely through activating NLRP3 inflammasome, and targeting inhibition of Piezo1 could be a novel therapeutic strategy against I/R-induced AKI.