Abstract
Abstract: :
Purpose: Introduction: Connective tissue growth factor (CTGF) is a cysteine-rich heparin-binding polypeptide that promotes proliferation, collagen synthesis, and chemotaxis in mesenchymal cells. CTGF promotes fibrosis in skin, and neovascularization in the cancer tissue. However, little is known about the involvement of CTGF in wound repair after corneal alkali burn, which is characterized by leukocyte infiltration, neovascularization and scar formation. The purpose of this study is to determine the role of CTGF in corneal wound healing using a chemical corneal wound model. Methods: A standardized 5.5-mm diameter penetrating central corneal alkali wound was induced in one eye in each of ten New Zealand white rabbits (2.5 kg). In five of the ten rabbits, 1.5 ml 5% fucoidin was given intravenously every 2 hours to prevent leukocytes from leaving the blood stream. CTGF in the corneas were localized using immunohistochemical staining 2 days after injury. Affinity-purified goat anti-CTGF at a 1:40 dilution and 1:200 biotinylated rabbit anti-goat antibody was used. Finally the sections were incubated with Texas Red-conjugated alkaline phosphate substrate reagent. The specimens were observed in a fluorescent microscope. Results: No positive CTGF staining was detected in the unwounded corneal cells. A positive expression of CTGF was observed in all three-cell types of regenerated corneal cells after 2 days wounding in the wounded areas. Positive staining was also seen in the leukocytes infiltrating in both the limbal and wounded stroma. More pronounced CTGF positivity was found in the presence of leukocytes. Conclusion: Alkali corneal injury induces CTGF production in the cells participating in corneal wound repair and in the infiltating leukocytes. Infiltrated leukocytes increase the expression of CTGF. Further studies are needed to clarify a relationship of CTGF production, corneal neovascularization and scar formation.
Keywords: 370 cornea: basic science • 631 wound healing • 374 cornea: stroma and keratocytes