The effect of cyclic mechanical strain on the expression of adhesion-related genes by periodontal ligament cells in two-dimensional culture

Saminathan A, Vinoth KJ, Wescott DC, Pinkerton MN, Milne TJ, Cao T, Meikle MC. The effect of cyclic mechanical strain on the expression of adhesion-related genes by periodontal ligament cells in two-dimensional culture. J Periodont Res 2012; 47: 212–221. © 2011 John Wiley & Sons A/S Background and Objective: Cell adhesion plays important roles in maintaining the structural integrity of connective tissues and sensing changes in the biomechanical environment of cells. The objective of the present investigation was to extend our understanding of the effect of cyclic mechanical strain on the expression of adhesion-related genes by human periodontal ligament cells. Material and Methods: Cultured periodontal ligament cells were subjected to a cyclic in-plane tensile deformation of 12% for 5 s (0.2 Hz) every 90 s for 6–24 h in a Flexercell FX-4000 Strain Unit. The following parameters were measured: (i) cell viability by the MTT assay; (ii) caspase-3 and -7 activity; and (iii) the expression of 84 genes encoding adhesion-related molecules using real-time RT-PCR microarrays. Results: Mechanical stress reduced the metabolic activity of deformed cells at 6 h, and caspase-3 and -7 activity at 6 and 12 h. Seventy-three genes were detected at critical threshold values