[Effect of tensile strain on perlecan expression of human periodontal ligament cells]

To investigate the perlecan expression of human periodontal ligament cells (hPDLCs) under cyclic tensile strain in vitro, and learn the molecular mechanism of periodontal remolding during tooth movement.

hPDLCs isolated by enzyme digestion were loaded with 12% elongation, 1 Hz of uniaxial tensile strain for 12, 24 and 48 h. The unloaded cells were used as control. Real-time PCR and enzyme-linked immune sorbent assay (ELISA) were applied to analyze the mRNA and protein expression of perlecen in each sample respectively. The data was analyzed with SPSS 19.0 software package.

Within 12 h, mRNA expression was transiently elevated, but no significant difference was detected compared with the control. After 12 h, the mRNA expression was significantly decreased. It would decreased to (0.28±0.049) at lowest level of control at lowest level at 48 h (P<0.05). The protein expression of perlecan was time-dependently decreased. Specifically, it was downregulated from (14.03±0.71) pg/mL (control) to (11.06±0.15) pg/mL at lowest level at 48 h (P<0.05).

Tensile strain time-dependently down-regulates perlecan expression, indicating perlecan may play a pivot role in PDLCS responding to mechanical loading in vitro.