Effects of Equiaxial and Uniaxial Tensile Strain Generated by Orthodontic Forces on Human Mesenchymal Stem Cells

The orthodontic force-induced tissue strain produces local alterations in cellular and extracellular matrix reorganization, leading to the transformation and differentiation of cells. The present study was designed to investigate the influence of mechanical force on the CD90 expression of human mesenchymal stem cells (endometrial stem cells and dental pulp stem cells). The mesenchymal stem cells from passage 3-5 were seeded onto silicone membrane and cultured in medium with or without static mechanical stimulation (equiaxial and uniaxial strains). After 2 weeks, cultured cells were analyzed for expression of CD90. After 14 days in culture, immunfluorescence staining of cultured MSC demonstrated that mechanical stimulation of MSCs compared with control group, resulted in decreased CD90 expression. The decrease of CD90 expression in mechanically stimulated cultures compared to unstimulated control cultures suggests the possibility of differentiation of stem cells to other cells.