Figure 3

Tendon progenitor cell (TPC) tendon marker gene expression as a function of growth factor treatments and loading. TPC gene expression on day (D)3 of treatment with combinations of mechanical loading (L), transforming growth factor (TGF)β2 (T), and fibroblast growth factor-(FGF)4 (F). Dashed horizontal line = 1 indicates control condition. (A) Scleraxis (Scx) was significantly upregulated by all treatments involving TGFβ2. (B) TGFβ2 and (C) tenomodulin (Tnmd) were significantly downregulated by TGFβ2 + FGF4 + loading. (D) Collagen type I (Col I) was significantly upregulated by TGFβ2 + loading. (E) Elastin (Eln) was significantly downregulated by all treatments that involve FGF4, but was significantly upregulated by TGFβ2 + loading. ↑ or ↓ indicates statistically significant up- or downregulation, respectively; *P < 0.05, **P < 0.01, ***P < 0.001.