2010 Fiscal Year Final Research Report
The role of tryptophan-niacin key enzymes in brain's immune system
| Project/Area Number |
20580122
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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 |
Food science
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| Research Institution | Chiba University |
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Principal Investigator |
EGASHIRA Yukari Chiba University, 大学院・園芸学研究科, 教授 (80213528)
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| Project Period (FY) |
2008 – 2010
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| Keywords | トリプトファン / ナイアシン / キノリン酸 / 神経毒 / ミクログリア / 脳 |
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| Research Abstract |
The L-tryptophan (Trp) metabolites such as L-kynurenine(Kyn), L-kinurenic acid, quinolinic acid (QA) and picolinic acid (PA) have been shown physiologically important in central nervous and immune system. Dietary dehydroisoandrosterone (DHEA) affects quinolinic acid (QA) production. The present study suggesting that the mechanism of decrease in ACMSD mRNA level by DHEA was different from that by WY-14,643, and that there would be any pathway other than PPARalpha mediated one for DHEA to regulate ACMSD expression.
In the STZ-induced diabetes group, the amount of [5-3H]L-Trp converted to tritiated water, L-Kyn or QA were found to be more than 3 times of that in the control group, respectively. It is suggested that STZ-diabetes mellitus causes augmentations of both L-Kyn and QA generations but not those of PA and Nam in liver, indicating the possibility that the immune and neuronal systems of insulin dependent diabetes mellitus would be influenced by the increased amounts of L-Kyn and QA but not by those of PA and Nam.
Inflammation-induced activation of the tryptophan catabolizing enzyme indoleamine 2,3-dioxygenase (IDO) causes increase of QA production. We investigated which dietary components affect IDO expression in microglial cells. This study suggests that some dietary polyphenols affected LPS-induced IDO expression in microglial cells.
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Research Products
(9 results)
