| Project/Area Number |
12670817
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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 | KYOTO UNIVERSITY |
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Principal Investigator |
YAMAOKA Junichi Kyoto University, Graduate School of Medicine, instructor, 医学研究科, 助手 (80283688)
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| Co-Investigator(Kenkyū-buntansha) |
TODA Kenichi Kyoto University, Graduate School of Medicine, lecturer, 医学研究科, 講師 (80159045)
AKAIKE Akinori Kyoto University, Graduate School of Pharmacology, professor, 薬学研究科, 教授 (80135558)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2001: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2000: ¥2,400,000 (Direct Cost: ¥2,400,000)
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| Keywords | NO(nitric oxide) / iNOS (inducible nitric oxide synthase) / epidermal keratinocyte / differentiation / cell adhesion molecule / vascula rendothelial cell / cell damage / inflammation / NO(nitric oxide) / iNOS(inducible nitric oxide synthase) / 接着因子 |
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| Research Abstract |
Cytokines such as IL-1α, IFN-γ and TNF-α are intimately involved in the pathogenesis of cutaneous inflammation. In sites of inflammation, inflammatory cytokines induce inducible nitric oxide synthase (iNOS) and subsequent production of large amounts of nitric oxide (NO). In the present study, to clarify how NO affects the pathogenesis of cutaneous inflammation, we examined effect of NO on cell adhesion molecule expression, cell differentiation, cell damage and cell growth. Expression of ICAM-1 in murine primary keratinocytes was compared among samples under three different conditions : 1. no stimulations, 2. stimulation with IFN-γ + TNF α(induction of iNOS with subsequent NO production), 3. stimulation with IFN-γ + TNF-α and the addition of iNOS specific inhibitor (induction of iNOS without subsequent NO production). Western blotting analyses revealed that (1) ICAM-1 expression was remarkably upregulated in samples 1 and 2 compared with sample 1. (2) Significant differences of ICAM-1 expression were not observed between samples 1 and 2. As to expression of transglutaminase-1 (TG-1) and involucrin, which regulate keratinocyte differentiation, there existed no significant differences between samples 2 and 3.
Cell damage induced by NO was examined by measuring LDH enzyme activity in the culture medium of murine keratinocytes cell line Pam 212 cells stimulated with various concentrations of NO donor. These experiments revealed that low doses of NO acted as cytoprotective, while high doses of NO cytotoxic.
Murine vascular endothelial cell line F-2 cells were injured when they were exposed to IFN-γ + TNF-α. We demonstrated by using iNOS specific inhibitor that this cytokines-induced endothelial cell damage was predominantly mediated by NO produced by stimulation with cytokines. These results suggested that inflammatory cytokines-induced iNOS induction and subsequent NO production might be responsible for endothelial cell injury observed in cutaneous inflammation.
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