Mechanosensitive cation channel Piezo1 contributes to ventilator-induced lung injury by activating RhoA/ROCK1 in rats.

BACKGROUND

Mechanical ventilation can induce or aggravate lung injury, which is termed ventilator-induced lung injury (VILI). Piezo1 is a key element of the mechanotransduction process and can transduce mechanical signals into biological signals by mediating Ca influx, which in turn regulates cytoskeletal remodeling and stress alterations. We hypothesized that it plays an important role in the occurrence of VILI, and investigated the underlying mechanisms.

METHODS

High tidal volume mechanical ventilation and high magnitude cyclic stretch were performed on Sprague-Dawley rats, and A549 and human pulmonary microvascular endothelial cells, respectively, to establish VILI models. Immunohistochemical staining, flow cytometry, histological examination, enzyme-linked immunosorbent assay, western blotting, quantitative real-time polymerase chain reaction and survival curves were used to assess the effect of Piezo1 on induction of lung injury, as well as the signaling pathways involved.

RESULTS

We observed that Piezo1 expression increased in the lungs after high tidal volume mechanical ventilation and in cyclic stretch-treated cells. Mechanistically, we observed the enhanced expression of RhoA/ROCK1 in both cyclic stretch and Yoda1-treated cells, while the deficiency or inhibition of Piezo1 dramatically antagonized RhoA/ROCK1 expression. Furthermore, blockade of RhoA/ROCK1 signaling using an inhibitor did not affect Piezo1 expression. GSMTx4 was used to inhibit Piezo1, which alleviated VILI-induced pathologic changes, water content and protein leakage in the lungs, and the induction of systemic inflammatory mediators, and improved the 7-day mortality rate in the model rats.

CONCLUSIONS

These findings indicate that Piezo1 affects the development and progression of VILI through promotion of RhoA/ROCK1 signaling.