Ps-124: Cyclic Stretch Stimulates Myh2 Expression in Differentiation of Mesenchymal Stem Cells into Skeletal Muscle Cells

Nourizadeh Abbariki T *, Shokrgozar MA , Haghighipour N , Mahdian R ,


Objective: Skeletal muscle cells have the potential to respond to environmental factors including biomechanical signals. Cyclic stretch is one of the important factors affecting differentiation of mesenchymal stem cells (MSCs) into skeletal muscle cells .The aim of this study was to illustrate the effect of environmental factors including chemical cues and cyclic strain on myogenic differentiation of MSCs by evaluation of myh2 expression. Materials and Methods: This study was designed within 5 days in 4 groups for MSCs: control, chemical, chemical-mechanical and mechanical groups based on BMSCs, after isolation from mouse. In chemical tests, MSCs were exposed to chemical growth factors, 5-azacythidine and horse serum, for 5 days. In mechanical tests, a cyclic axial stretch device, developed in National Cell Bank of Pasteur Institute of Iran, was used for mechanostimulation. MSCs cultured on collagen type1 coated silicon membrane were subjected to cyclic stretch (8% strain, 1 Hz freq. and 24 hours). In chemical-mechanical tests, MSCs were loaded for 24 hours after they were treated by differentiation medium. MSCs were used in negative control group. In order to investigate the myogenic differentiation of MSCs Real-Time PCR was used to examine the expression of skeletal muscle cell specific gene, myosin heavy chain 2 (Myh2). Immunocytochemical staining with skeletal muscle cell antibody, Myh, was carried out in order to detect the presence of skeletal muscle cell marker. Results: According to the results, chemical-mechanical groups showed a higher expression of Myh2 (20.7 folds) in comparison to mechanical (8.94 folds), and also chemical (5.2 folds) ones. Conclusion: These Results suggest that uniaxial cyclic strain alone can affect myogenic differentiation of MSCs. The combination of chemical with mechanical factors stimulates differentiation much more than differentiation by chemical factors or mechanical signals alone and produces functional skeletal muscle cells for engineered tissues.