[Piezo1-mediated mechanosensing accelerates acute inflammatory stress in periodontal tissues following dental trauma].

Objective: To investigate the potential mechanism by which the mechanically sensitive ion channel protein Piezo1 responds to mechanical pressure to regulate acute inflammatory stress in periodontal tissue following dental trauma. Methods: An inflammatory model of human gingival fibroblasts (HGF) was induced using lipopolysaccharide (LPS), followed by the use of a hydrostatic pressure loading system to construct a HGF mechanical stress-inflammation composite model, simulating the mechanical microenvironment of dental trauma. The cell counting kit-8 assay, scratch test, real-time fluorescence quantitative PCR (RT-qPCR), and immunofluorescence staining were employed to assess cell viability, migration ability, inflammatory factor expression levels, and cytoskeletal morphology. The Piezo1-specific agonist Yoda1 and inhibitor Dooku1 were used to intervene in the HGF mechanical stress-inflammation composite model to evaluate inflammation-related biological behaviors of cells. Transcriptomics was used to screen the biological mechanisms by which Piezo1-mediated mechanosensation accelerates acute periodontal inflammation after dental trauma, validated by Western blotting assays. Results: A HGF mechanical stress-inflammation composite model was established using 1 g/cm² (1 g/cm2=0.01 N/cm2) hydrostatic pressure combined with 1 μg/ml LPS. Compared with the control group, cells in the model group showed significantly reduced proliferation and migration abilities, with notable increases in interleukin (IL)-6, IL-8, C-C motif chemokine ligand 2, and Piezo1 mRNA expression (P<0.05). Treatment of the composite model with 5 μg/ml Yoda1 exacerbated these phenotypes, reducing the proportion of live cells at 48 h to [(37.74±0.97)%] (P<0.01) and upregulating inflammatory factor expression (P<0.01), while 5 μg/ml Dooku1 reversed these effects, increasing live cells to [(59.49±0.62)%] (P<0.01), downregulating inflammatory factor expression, and restoring cell function (P<0.05). Transcriptome sequencing indicated that mechanical stress-inflammation stimulation enhanced mechanical stress response and calcium signal release, coordinating the mechanoadaptive inflammatory microenvironment. Western blotting assays confirmed elevated protein expression of Piezo1, cyclic adenosine monophosphate (cAMP), protein kinase cAMP-activated catalytic subunit alpha, matrix metalloproteinase-3, P-AKT1, and CREB1 in the composite model group, further upregulated by Yoda1 and inhibited by Dooku1. Conclusions: Abnormal mechanical forces during dental trauma activate the mechanically sensitive ion channel protein Piezo1, triggering the AKT1/CREB1 signalling pathway, thereby driving overexpression of inflammatory factors, inhibiting cell migration, and ultimately exacerbating periodontal tissue inflammation.