Induction of connective tissue growth factor in retinal pigment epithelium cells by oxidative stress

Purpose: To investigate whether connective tissue growth factor (CTGF) is upregulated in the retinal pigment epithelium (RPE) by oxidative stress in vitro and in vivo. Methods: ARPE19 cells were subjected to two forms of oxidative stress: hypoxia/reoxygenation and paraquat exposure. CTGF expression was studied by real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot analysis. The ocular expression of CTGF was analyzed by RT-PCR and immunohistochemistry in an in vivo murine model of oxidative stress exposed to light after intravenous injection of rose bengal. Results: CTGF mRNA expression in ARPE19 cells was upregulated by oxidative stress and peaked 1 h after reoxygenation; protein expression peaked 2h after reoxygenation. Using paraquat, both CTGF mRNA and protein were upregulated by five doses of paraquat. In vivo, CTGF was upregulated when evaluated by RT-PCR and immunohistochemistry using murine retinas stimulated by oxidative stress. Conclusions: Upregulation of CTGF expression was confirmed in RPE cells by oxidative stress in vitro and in vivo. CTGF might be one of the factors that induces the changes observed in aging retinas.