Mechanical stretch-mediated fibroblast activation: The pivotal role of Piezo1 channels.

Mechanical forces are crucial in regulating fibroblast behavior, yet the underlying mechanisms remain unclear. This study aims to elucidate the role of the Piezo1 ion channel in fibroblast responses to mechanical stimulation. A mechanical stimulation culture platform was developed using a polydimethylsiloxane (PDMS)-based stretchable membrane and the Cell Tank uniaxial cell stretching system. Fibroblasts subjected to uniaxial cyclic stretching were analyzed using proteomic profiling, Western blotting, and confocal laser scanning microscopy to assess cytoskeletal changes and activation markers. Immunofluorescence staining was performed to evaluate the expression of Piezo1, YAP1, and Ki67 proteins. Cell viability and migration capacity were assessed using Calcein-AM/PI double staining and a migration assay. Mechanical stretch-induced fibroblast activation is characterized by morphological changes, increased proliferation, and enhanced migration. The cytoskeletal reorganization was observed, with elevated F-actin expression. Modulating Piezo1 activity altered fibroblast activation, indicating its essential role in mechanotransduction. These findings demonstrate that mechanical stretch upregulates Piezo1 expression, promoting fibroblast activation through the YAP pathway. This study provides new insights into the mechanotransduction mechanisms in fibroblasts and highlights the critical role of Piezo1 in mediating responses to mechanical stimuli, which may have implications for understanding tissue remodeling and fibrosis.