| Project/Area Number |
18591017
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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 |
Endocrinology
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| Research Institution | Nagoya University |
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Principal Investigator |
KAMBE Fukushi Nagoya University, Res, Instit, Environ. Med, Assoc. Prof. (00211871)
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| Co-Investigator(Kenkyū-buntansha) |
SEO Hisao Nagoya University, Res, Instit, Environ. Med, Prof (40135380)
SAWADA Makoto Nagoya University, Res, Instit, Environ. Med, Prof (10187297)
CAO Xia Nagoya University, Res, Instit, Environ. Med, Assit. Prof (70432218)
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| Project Period (FY) |
2006 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥3,800,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥300,000)
Fiscal Year 2007: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2006: ¥2,500,000 (Direct Cost: ¥2,500,000)
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| Keywords | DHCR24 / ER stress / oxidative stress / hydrogen peroxide / tunicamycin / ASK-1 / p38 MAPK / JUK / 活性酸素 |
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| Research Abstract |
3β-Hydroxysteroid-A24 reductase(DHCR24) is an endoplasmic reticulum(ER) -resident, multifunctional enzyme that possesses anti-apoptotic and cholesterol-synthesizing activities. To clarify the molecular basis of the former activity, we investigated the effects of hydrogen peroxide(H_2O_2) on embryonic fibroblasts prepared from DHCR24-knockout mice(DHCR244- MEFs). H_2O_2 exposure rapidly induced apoptosis, which was associated with sustained activation of apoptosis signal-regulating kinase(ASK) -1 and stress-activated protein kinases, such as p38 mitogen-activated protein kinase(MAPK) and c-Jun N-terminal kinase(JNK). Complementation of the MEFs by adenovirus expressing DHCR24 attenuated the H_2O_2-induced kinase activation and apoptosis. Concomitantly, intracellular generation of reactive oxygen species(ROS) in response to H_2O_2 was also diminished by the adenovirus, suggesting a ROS-scavenging activity of DHCR24. Such anti-apoptotic effects of DHCR24 were duplicated in pheochromocytoma PC12 cells infected with adenovirus. In addition, it was found that DHCR24 exerted cytoprotective effects in the tunicamycin-induced ER stress by eliminating ROS. Finally, utilizing in vitro synthesized and purified proteins, DHCR24 and its C-terminal deletion mutant were found to exhibit high H_2O_2-scavenging activity, while the N-terminal deletion mutant lost such activity. These results demonstrate that DHCR24 can directly scavenge H_2O_2, thereby protecting cells from oxidative-stress-induced apoptosis
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