Periodic Mechanical Stress Enhances Rat Chondrocyte Area Expansion Adn Migration In Part Through The Src-PLCγ1-ERK1/2 Signaling Pathway

PartⅠPeriodic mechanical stress enhances rat chondrocyte area expansion and migrationObjective To explore whether periodic mechanical stress could enhance rat chondrocyte area expansion and migration.Methods Rat chondrocytes derived from the second generation were cultured in vitro for 0 h,0.5 h,1 h and 2 h, with or without periodic mechanical stress (a self-developed periodic stress field and perfusion culture system with pressure varying from 0 to 200 KPa and frequency of 0.1 Hz). Cell area was analyzed using Image-Pro Plus 5.0 software. In a second experiment, rat chondrocytes derived from the same conditions were cultured in vitro for 12 h, with or without periodic mechanical stress. Cell migration ability was measured by scratch-healing assay.Results Under periodic mechanical stress, chondrocyte area was significantly amplified, and migration ability was significantly enhanced (p<0.05).Conclusions Periodic mechanical stress promotes chondrocyte area expansion and migration. PartⅡPeriodic mechanical stress changes the phosphorylation levels of Src, PLCγ1 and ERK1/2 in rat chondrocyteObjective To explore phosphorylation levels of Src, PLCγ1 and ERK1/2 under periodic mechanical stress.Methods Rat chondrocytes derived from the second generation were cultured in vitro for 0 h,0.5 h,1 h and 2 h, with or without periodic mechanical stress (a self-developed periodic stress field and perfusion culture system with pressure varying from 0 to 200 KPa and frequency of 0.1 Hz). The expression and phosphorylation levels of ERK1/2, PLCγ1 and Src kinase were detected by western blotting.Results Under periodic mechanical stress, the phosphorylation levels of Src, PLCγ1 and ERK1/2 were significantly increased (p<0.05,n=5).Conclusions Periodic mechanical stress enhances the phosphorylation levels of Src, PLCγ1 and ERK1/2 in rat chondrocyte.PartⅢPeriodic mechanical stress enhances rat chondrocyte area expansion and migration in part though Src, PLCγ1 and ERK1/2Objective To explore if the Src, PLCγ1 and ERK1/2 affect the rat chondrocyte area expansion and migration under periodic mechanical stress.Methods After pretreatment with Src inhibitor (PP2), PLCγ1 inhibitor (U73122) and ERK1/2 inhibitor (PD98059), rat chondrocytes derived from the second generation were cultured in vitro for 0 h,0.5 h,1 h and 2 h, with periodic mechanical stress (a self-developed periodic stress field and perfusion culture system with pressure varying from 0 to 200 KPa and frequency of 0.1 Hz). Cell area was analyzed using Image-Pro Plus 5.0 software. In a second experiment, rat chondrocytes derived from the same conditions were cultured in vitro for 12 h. Cell migration ability was measured by scratch-healing assay.Results Under periodic mechanical stress, in the PP2,U73122 and PD98059 pretreatment group, cell area expansion, cell migration were significantly inhibited (p<0.05). Conclusions Periodic mechanical stress promotes chondrocyte area expansion and migration in part through the Src, PLCγ1 and ERK1/2 signaling protein.PartⅣThe relationship among Src, PLCγ1 and ERK1/2 in rat chondrocyte under periodic mechanical stressObjective To explore the relationship among Src, PLCγ1 and ERK1/2 under periodic mechanical stress in rat chondrocyte.Methods After pretreatment with Src inhibitor (PP2), PLCγ1 inhibitor (U73122) and ERK1/2 inhibitor (PD98059), rat chondrocytes derived from the second generation were cultured in vitro for 0 h,0.5 h,1 h and 2 h, with periodic mechanical stress (a self-developed periodic stress field and perfusion culture system with pressure varying from 0 to 200 KPa and frequency of 0.1 Hz). The expression and phosphorylation levels of ERK1/2, PLCγ1 and Src kinase were detected by western blotting.Results Under periodic mechanical stress, in the PP2 pretreatment group, the phosphorylation sites of PLCγ1-Tyr783 and ERK1/2-Thr202/Tyr204 were inhibited (p<0.05). In the U73122 pretreatment group, the phosphorylation sites of ERK1/2-Thr202/Tyr204 were significantly inhibited (p<0.05), while the phosphorylation site of Src-Tyr418 was not affected. In the PD98059 pretreatment group, the phosphorylation sites of Src-Tyr418 and PLCγ1-Tyr783 were not affected.Conclusions Periodic mechanical stress promotes chondrocyte in part through the Src-PLCγ1-ERK1/2 signaling pathway...