| Project/Area Number |
14570796
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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 |
Dermatology
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| Research Institution | AKITA UNIVERSITY |
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Principal Investigator |
YONEDA Kozo Akita University, School of Medicine, Lecturer, 医学部, 講師 (60260626)
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| Co-Investigator(Kenkyū-buntansha) |
MANABE Motomu Akita University, School of Medicine, Professor, 医学部, 教授 (30138309)
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| Project Period (FY) |
2002 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2003: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 2002: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | keratin / keratin disease / Transfection / Ubiquitin / 20S proteasome / トランスフェクション |
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| Research Abstract |
Epidermolysis bullosa simplex (EBS) is a blistering cutaneous disease featuring protein aggregates. Here we investigate the molecular mechanisms linking protein aggregates to cell death in a cellular model of EBS in which HaCaT keratinocytes are transfected with plasmids expressing various mutant forms of keratin 14 (K14). In HaCaT cells, mutant K14 was found to form protein aggregates that suppressed 20S proteasome function instead of being 20S proteasome. Keratinocytes with mutant K14 induced phosphorylation of the kinase c-Jun, as well as up-regulation of unfolding protein Bip, indicating endoplasmic reticulum (ER) stress. HaCaT cells were susceptible to apoptosis by caspases-3, and -8, but not caspase-9 or -12. Tumor necrosis factor-α(TNFα) in the culture medium was increased in keratinocytes with mutant K14 compared to wild K14, and the addition of neutralizing anti-TNFα antibody to the culture medium rescued keratinocytes from cell death. Thus, TNFα release and the subsequent activation of the TNFα receptor by an autocrine/paracrine pathway links protein aggregates to cell death in this keratinocyte EBS cellular model. Furthermore, mutation in K14 reduced its affinity to TNFα receptor-associated death domain (TRADD), suggesting that the susceptibility of keratinocytes to caspase-8-mediated apoptosis is increased in mutated K14 due to impairment of the cytoprotective mechanism
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