Piezo1 Mediates Inflammation in Balloon-inflated Rat Brain and its Bidirectional Mechanosensitivity

Brain injury after intracerebral hemorrhage is extremely complicated, and the exact mechanism remains puzzling. Piezo1, a novel mammalian mechanosensitive ion channel, has been identified to play important roles in several pathologic and physiologic procedures that involve cellular mechanotransduction. However, the role of Piezo1 in hematoma compression after intracerebral hemorrhage is still unclear.In the present study, we established a balloon-inflated brain model based on an adult male rat mimicking the pure mechanical compression of a hematoma. Then the behavioral assessment (Garcia Scale) was taken to observe the syndrome after "hematoma". Western blotting and immunofluorescence were applied to detect Piezo1 expression around lesions in rat brains. ELISA was used for quantitative analysis of inflammation factors. A statistical significance was confirmed as P value<0.05.Balloon compression lesions were detected in the basal ganglia region of the brain, resulting in abnormal behaviors and a significant increase in the expression of Piezo1 and proinflammatory cytokines. GsMTx4, an antagonist of Piezo1, reversed these effects. Additionally, the balloon deflation time affected behavioral function and the levels of Piezo1 and proinflammatory cytokines.These results establish the first in vivo evidence for the role of Piezo1 in blood-brain neuroinflammation after hematoma compression. Piezo1 showed "bidirectional mechanosensitivity" and therefore is a potential therapeutic target for the treatment of intracerebral hemorrhage.