The Expression of Connective Tissue Growth Factor by Hyalocytes

Abstract

Abstract: : Purpose: To investigate the expression of connective tissue growth factor (CTGF) by cultured hyalocytes and its regulation by TGF–ß2. Methods: The hyalocytes were isolated from bovine vitreous. The cells were embedded in type I collagen gels and stimulated with TGF– ß2. The hyalocytes were retrieved from the gels with collagenase treatment and total RNA was extracted. The expression of CTGF mRNA was analyzed by Northern blot analysis. Cytoplasmic and nuclear extracts were also isolated to examine the nuclear translocation of transcription factor Smad4, which is considered to play an important role in the expression of CTGF gene, by Western blot analysis. Furthermore, we addressed the effect of Rho–kinase inhibitor on the nuclear translocation of Smad4 and the expression of CTGF gene. Results: TGF– ß2 caused a nuclear translocation of Smad4 and significantly promoted the expression of CTGF gene by hyalocytes. The Rho–kinase inhibitor, however, significantly prohibited the nuclear translocation of Smad4 and the expression of CTGF gene. Conclusions: The hyalocytes might play a role in modifying vitreo–retinal interface diseases via expression of CTGF. It is also suggested that the Rho–kinase inhibitor has therapeutic potential to inhibit aberrant fibrosis of proliferative tissue.

Keywords: gene/expression • vitreous • growth factors/growth factor receptors