Mechanical Stress Regulates Osteogenesis and Adipogenesis of Rat Mesenchymal Stem Cells through PI3K/Akt/GSK-3β/β-Catenin Signaling Pathway

Figure 3

Effects of different levels of mechanical stress on BMSCs differentiation. BMSCs were exposed to different levels of mechanical stress for 30 min and cultured in adipogenic medium or general medium for 7 days. (a) The adipogenesis of BMSCs was confirmed by Oil Red O staining. (A) No obvious intracellular lipid droplet formed in the control group; (B) a moderate amount of intracellular lipid droplet formed in the group of unloading + adipogenic medium; (C) a slight amount of intracellular lipid droplet formed in the small-magnitude stress + adipogenic medium group; (D) a substantial amount of intracellular lipid droplet formed in the large-magnitude stress + adipogenic medium group. Bars = 50 μm. (b) The expression levels of Runx2, Collagen I, C/EBPα, and PPARγ in BMSCs were examined by Western blot. (c) Quantitative analysis. versus control group; versus unloading + adipogenic medium group; versus small-magnitude stress + adipogenic medium group. Each value was presented as mean ± SD of three separate experiments and data of the treatment group was expressed as fold change versus that of control group (labeled as “1.00”). S represented small-magnitude stress; L represented large-magnitude stress. Cells cultured in general medium without mechanical loading as control.

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