WIP 88 - Piezo1 mediates vascular remodelling via Smurf1 in pulmonary arterial hypertension induced by IUGR

Poster Number: WIP 88
Publication Number: WIP 88.837

Background: Intrauterine growth retardation (IUGR) is closely associated with pulmonary hypertension (PH) in adults. The reprogramming of pulmonary artery smooth muscle cells (PASMCs) is subjected to various mechanical forces in vivo. As a mechanosensitive channel, Piezo1 directly transduces external mechanical stimulation into cellar molecular response.

Objective: We aimed to investigate the potential mechanisms of Piezo1 in IUGR-related pulmonary vascular remodelling.

Design/Methods: We found that IUGR adult rats subjected to two weeks of hypoxia displayed increased pulmonary artery pressure. Results from qRT-PCR and Western blot demonstrated that Piezo1 expression upregulated in lung tissues and PASMCs of rats with IUGR-related PAH. Moreover, the alteration of expression level of Piezo1 was coupled with pathological phenotypes of PASMCs of IUGR-related PAH rats, including increased cell proliferation, cell invasion and intracellular reactive oxygen species (ROS), as confirmed by EdU proliferation assay, transwell invasion assay and ROS measurement. Subsequently, we proved that siPiezo1 decreased Hif1a and Fhl1 expression in nucleus. Gsmtx4 (Piezo1 inhibitor) remarkably alleviated the severity of PAH in IUGR-related PAH rats, concurrently reducing PASMCs proliferation, invasion and the ROS levels. Furthermore, a microarray dataset of rat fibroblasts in control and shPiezo1 groups was obtained from the Gene Expression Omnibus databases. Analysis of this dataset revealed that Piezo1 knockdown induced the increased expression of TGF-β signaling. Furthermore, Piezo1 inhibitor or agonists in vitro modulated the expression of Smurf1 protein. Our immunoprecipitation experiment and immunoblotting further showed that Piezo1 binds with Smurf1 in nucleus.
Given the relevance of Hif1a and Fhl1 to the TGF-β pathway, our future investigations aim to elucidate how Piezo1 regulates their expression via Smurf1. We plan to determine whether their bindings are direct and identify their interacting domains through deletion mutations and immunoprecipitation experiments from November to December.