Cyclic Stretch Enhances Osteogenic Differentiation of Human Periodontal Ligament Cells via YAP Activation

Figure 5

Activation of YAP in HPDLCs was mediated by cytoskeleton remodeling. (a) Y27632 (20 μM) and Blebbistatin (20 μM) suppressed the nuclear translocation of YAP in HPDLCs after cyclic stretching. Scale bars indicate 50 μm. (b) Quantitatively analysis of the distribution patterns of YAP (in (a)). The patterns were categorized as mainly nuclear (N>C), diffuse (N=C), and mainly cytoplasmic (N<C). (c) Alkaline phosphatase activity was decreased in the Y27632- and Blebbistatin-treated HPDLCs after cyclic stretching. The positive cells were stained with NBT-formazan (dark blue). (d) The ALP activities were quantified using an ALP reagent kit. The activities were normalized to the protein concentration. , P < 0.05 vs control group; ^#, p < 0.05 vs tension group. (e and f) The mRNA expression levels of osteogenesis related genes in HPDLCs were decreased in the presence of Y27632 (e) or Blebbistatin (f) with cyclic stretch treatment. The relative expression levels of YAP, osteopontin (OPN), RUNX2, collagen type 1 (COL1), and alkaline phosphatase (ALP) were normalized to GAPDH. , p < 0.05; , p < 0.01. All data was based on three independent experiments.

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