The Effect Of Audio-directed Tension With Variable Frequency And Low Amplitude On The Osteogenic Differentiation Of Mesenchymal Stem Cells

In order to explore the biological effects of tension on mesenchymal stem cells,a new device which could remain static tension and respond to audio,producing dynamic tension with variable frequency and low amplitude was successfully developed.Results illustrated that there was no significant change in cell morphology under both dynamic and static tension.However,more stress fibers were formed throughout the cells,arranging along the long axis of the cells.Under osteogenic induction,cells cultured under dynamic tension showed an increase in the Runx2 and Ocn expression,and superior mineralized nodules formation,while no significant effect on osteogenesis was observed under static tension.Gene expression profiles of both groups were further analyzed RNA-Seq technique;compared with the control group,gene expressions of dynamic and static tension group were similar.The 16 differential expression genes of dynamic tension and control group involved in bone development and osteogenic differentiation were screened and analyzed.Compared with static tension,dynamic tension demonstrated more significant biological effects on cell adhesion,migration and autophagy of mesenchymal stem cells.In addition,the biological effects of dynamic tension might be regulated by focal adhesion,ECM receptor interaction,PI3K-Akt signaling pathway and TGF-beta signaling pathway.This study aims to provide basic theories and criterions in applications for bone tissue engineering by revealing the biomechanical effect of dynamic and static tension on MSCs.