PURPOSE: Tenascin (TN) is a large hexameric extracellular matrix glycoprotein that is expressed in developing organs and tumors. It has also been reported that TN is expressed in the embryonic cornea and during corneal wound healing. However, the role of TN in the cornea is not fully known. In this study, the role of TN in corneal wound healing was examined using the TN knockout (KO) mouse. METHODS: Two different injuries (a linear perforation wound and two 10-0 nylon suture wounds) were made separately on the corneas of both TNKO and congenic wild-type mice. The corneal wound healing was compared histologically, and the expression of TN and fibronectin (FN) on the injured cornea was examined immunohistochemically and by immunoblot analysis. RESULTS: Based on histologic analysis, there was no significant difference in the wound healing process between wild-type and TNKO mice in the linear incision experiment. However, the corneal stromata of TNKO mice were compressed prominently and devoid of migrating keratocytes in suture injury, which induced a more significant amount of TN than perforation wounds. Although FN expression on the sutured corneas of TNKO mice was upregulated during suture injury, the amount of FN protein was smaller than that of wild-type mice at the same time points after injury. CONCLUSIONS: In suture wounds, TN appears to enhance the amount of FN expression, and a lack of TN may impair stromal cell migration. TN plays a significant role in corneal wound healing, especially for wounds with mechanical stress.
PURPOSE:Tenascin (TN) is a large hexameric extracellular matrix glycoprotein that is expressed in developing organs and tumors. It has also been reported that TN is expressed in the embryonic cornea and during corneal wound healing. However, the role of TN in the cornea is not fully known. In this study, the role of TN in corneal wound healing was examined using the TN knockout (KO) mouse. METHODS: Two different injuries (a linear perforation wound and two 10-0 nylon suture wounds) were made separately on the corneas of both TNKO and congenic wild-type mice. The corneal wound healing was compared histologically, and the expression of TN and fibronectin (FN) on the injured cornea was examined immunohistochemically and by immunoblot analysis. RESULTS: Based on histologic analysis, there was no significant difference in the wound healing process between wild-type and TNKO mice in the linear incision experiment. However, the corneal stromata of TNKO mice were compressed prominently and devoid of migrating keratocytes in suture injury, which induced a more significant amount of TN than perforation wounds. Although FN expression on the sutured corneas of TNKO mice was upregulated during suture injury, the amount of FN protein was smaller than that of wild-type mice at the same time points after injury. CONCLUSIONS: In suture wounds, TN appears to enhance the amount of FN expression, and a lack of TN may impair stromal cell migration. TN plays a significant role in corneal wound healing, especially for wounds with mechanical stress.