2002 Fiscal Year Final Research Report Summary
Apoptosis cascade in hyperoxia-induced photoreceptor cell death.
| Project/Area Number |
13671858
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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 | Kansai Medical University |
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Principal Investigator |
MATSUMURA Miyo Kansai Medical University, Faculty of Medicine, Professor, 医学部, 教授 (30144380)
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| Co-Investigator(Kenkyū-buntansha) |
YAMADA Haruhiko Kansai Medical University, Faculty of Medicine, Instructor, 医学部, 助手 (50288841)
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| Project Period (FY) |
2001 – 2002
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| Keywords | hyperoxia / apoptosis / retinal cell / Ocaspase |
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| Research Abstract |
Purpose: Hyperoxia causes vascular endothelial cell and photoreceptor cell dropout in the mouse retina. We previously demonstrated that hyperoxic photorecepter cell death started from around day 5 of oxigen exposure and peaked on day 7. Our purpose in this study is to investigate the mechanisms by which these cells die from hyperoxic stress in vivo.
Method: C57bl/6j mice were exposed to a 75% concentration of oxygen for 1, 2 or 3 weeks. At each time point the mice were sacrificed and enucleated. Retinas were isolated from the eye balls, homogenized , and processed for protein isolation. To quantitate the protein levels of each apoptosis associated proteins, we performed Western blotting using antibodies of FAS, FAS-L, Bax, Bcl-2, Caspase 3, 8, and Caspase 9. To investigate the role of Fas and Fas-L proteins in this apoptosis pathway, we exposed FAS knockout mouse and FAS-L knokuout mouse under hyperoxic condition and quantitate the TUNEL index from their retinal sections.
Results: Western blotting revealed upregulation of Caspase 3 and Bax in the retinas after one week exposure in hyperoxia. FAS knockout mouse and FAS-L knockout mouse exposed to hyperoxia showed no difference of the TUNEL index compared to wild type mouse control.
Conclusion: The mechanisms by which apoptosis occurs in photoreceptor cells death is still unclear, but upregulation of Bax may play a key role in this apoptosis cascade. FAS and FAS-L are unlikely to involve in photoreceptor apoptosis from hyperoxia.
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