Figure 5

(a) Relative mRNA expression of transforming growth factor β1 (TGFβ1) in the cornea of wild-type (WT) and tenascin C-null (knockout (KO)) mice as examined by real-time reverse transcription PCR (RT-PCR). At day 5, mRNA expression of TGFβ1 is significantly higher in a WT cornea as compared with that in a KO cornea. At day 10 its expression decreases in a WT cornea. However, a significant difference between a WT and a KO samples was not detected at this timepoint. *P<0.05, **P<0.01. (b) Immunohistochemical detection of secreted, active form of TGFβ1 in a healing cornea. Secreted, activated form of TGFβ1 is not detected in a cornea of a WT (A, A′) or a KO (B, B′) cornea immediately after the incision wounding. At day 5, active form of TGFβ1 is detected in the stroma adjacent to the wound in a WT cornea, whereas the stroma that faces the incision injury is free from the active form of TGFβ1 in a KO mouse. A higher magnification picture shows that active TGFβ1 (asterisk) is found to be deposited beneath the regenerated epithelium of a WT healing cornea (C′). Matrix as well as keratocytes (star) are not labeled for active TGFβ1 in a KO tissue at this timepoint (D′). At day 10, active, secreted form of TGFβ1 is detected in the healing stroma of both WT (E) and KO (F) cornea. Active TGFβ1 (asterisk) is mainly detected in the stroma beneath the regenerated epithelium of a WT (E′) and KO (F′) healing cornea. Frames A′–F′ show the higher magnification pictures of the quadrilateral area in each of frames A–F. Nuclear staining, hematoxylin; epi, corneal epithelium; stroma, corneal stroma; glan, granulation tissue; scale bar, 100 μm (A–F) and 25 μm (A′–F′).