2005 Fiscal Year Final Research Report Summary
The mechanisms of the induced expression of CTGF and MMP in RPE cells after oxidative stress
| Project/Area Number |
15591856
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Ophthalmology
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| Research Institution | Osaka University |
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Principal Investigator |
GOMI Fumi Osaka University, Graduate School of Medicine, Lecturer, 医学系研究科, 講師 (80335364)
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| Co-Investigator(Kenkyū-buntansha) |
IKUNO Yasushi Osaka University, Graduate School of Medicine, Assistant, 医学系研究科, 助手 (50294096)
OSHIMA Yusuke Osaka University, Graduate School of Medicine, Assistant, 医学系研究科, 助手 (20362717)
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| Project Period (FY) |
2003 – 2005
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| Keywords | Age-related macular degeneration / retinal pigment epithelium / oxidative stress / CTGF / MMP |
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| Research Abstract |
To investigate whether connective tissue growth factor (CTGF) is up-regulated in the retinal pigment epithelium (RPE) by oxidative stress in vitro and in vivo, 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. As a result, CTGF mRNA expression in ARPE19 cells was up-regulated by oxidative stress and peaked 1 h after reoxygenation ; protein expression peaked 2 h after reoxygenation. Using paraquat, both CTGF mRNA and protein were up-regulated by five doses of paraquat. In vivo, CTGF was up-regulated when evaluated by RT-PCR and immunohistochemistry using murine retinas stimulated by oxidative stress.
Next, we added triamcinolone acetonide (TA) to ARPE19 cells exposed to oxidative stress.to investigate whether TA affects the expression of vascular endothelial growth factor (VEGF) and CTGF in RPE cells exposed to oxidative stress. We found TA reduced up-regulation of VEGF and TGF-B in a concentration-dependent manner. In contrast, up-regulation of CTGF by oxidative stress was accelerated by TA concentrations of 10 nM and 1 μM. Tube formation by HUVECs was strongly inhibited by exposure to conditioned medium from oxidative stress-stimulated ARPE 19 cells treated with 1 μM TA compared to cells not treated with TA.
In conclusion, CTGF expression was up-regulated 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. CTGF is also a main cytokine related to fibrosis, therefore, possible role on the fibrosis of choroidal neovascularization after TA administration was suggested.
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