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. 2013 Jul 25;123(8):3564–3576. doi: 10.1172/JCI67521

Figure 8. EGR1 promotes the formation of tendon-like tissues in a rat model for tendon injury.

Figure 8

(A) Achilles tendons of adult nude rats were separated from the plantaris and soleus tendons. A total transverse section of the Achilles tendon was created, and both ends were immediately sutured back together with surgical sutures. C3H10T1/2 or C3H10T1/2-EGR1 cells were then implanted in the injured/sutured tendon. C3H10T1/2- and C3H10T1/2-EGR1–grafted tendons were morphologically and histologically analyzed by H&E staining of sections along the axis of the tendon, 2 (B–E) and 3 (F–I) weeks after manipulation. (F and G) Holes left by the suture points are indicated by ellipses. All the longitudinal sections (B–I) are orientated bone to the left and muscle to the right. (J) qRT-PCR analyses of tendon gene expression in nonmanipulated tendons, sham tendons (with no cell application), C3H10T1/2-grafted tendons, and C3H10T1/2-EGR1–grafted tendons 2 weeks after the operation. mRNA levels of nonmanipulated tendons were normalized to 1. (K) Collagen quantity was assessed using a hydroxyproline assay in nonmanipulated tendons, sham tendons, C3H10T1/2-grafted tendons, and C3H10T1/2-EGR1–grafted tendons 2 and 3 weeks postoperation. Error bars represent SD (J and K). *P < 0.05; **P < 0.01; ***P < 0.001, unpaired Student’s t tests. Scale bars: 1 cm (A); 1 mm (B, C, F, and G); 100 μm (D, E, H, and I).