牙周膜干细胞对细胞外基质刚度的力学响应

Objective To investigate the mechanoresponse mechanisms of periodontal ligament stem cells (PDLSCs)to matrix stiffness. Methods Hydrogel substrates with gradient stiffness (5, 15, 25, 45, 65, and 125 kPa)were constructed for PDLSCs culture. Immunofluorescence staining was used to analyze cell spreading area, FAK Y397 phosphorylation, YAP nuclear localization, F-actin organization, and Lamin A/C expression. Western blotting was employed to validate FAK Y397 phosphorylation levels. Statistical analysis was performed to compare cellular behavior and signaling molecule changes under different stiffness conditions. For comparisons between two groups, two-tailed Student’s t-test was used, while for comparisons among multiple groups, Tukey’s post hoc test was applied. Results With increasing substrate stiffness, cell spreading area significantly expanded, FAK Y397 phosphorylation levels elevated, actin fiber cap formation enhanced, cytoskeletal alignment became more organized, nuclear flattening intensified, and ultimately YAP nuclear translocation rates markedly increased(5 kPa 1.09±0.14 vs.125 kPa 3.69 ± 0.54, P < 0.05). Conclusion Matrix stiffness regulates PDLSCs morphology and molecular responses through the mechanosensitive signaling pathway (FAK-cytoskeleton-YAP). This study confirms that the biophysical microenvironment provided by substrate stiffness is a key factor influencing stem cell behavior, thus offering new targets for optimizing PDLSC-mediated periodontal regeneration strategies.