Dietary linoleic acid suppresses gene expression of rat liver alpha-amino-beta-carboxymuconate-epsilon-semialdehyde decarboxylase (ACMSD) and increases quinolinic acid in serum.
Hepatic ACMSD [EC4.1.1.45] plays a key role in regulating NAD biosynthesis from tryptophan. We previously reported that ingestion of polyunsaturated fatty acids by rats leads to a decrease in their hepatic ACMSD activity. We purified ACMSD and cloned cDNA encoding rat ACMSD. Therefore, in this study, we examined whether dietary linoleic acid altered ACMSD gene expression and its protein level. Moreover we measured the tryptophan catabolite quinolinic acid level in rats. In the rats fed with linoleic acid, ACMSD mRNA and its protein levels in the liver were strongly suppressed and serum quinolinic acid was significantly increased as compared with the rats fed on a fat-free diet. These results suggest that the transcription level of ACMSD is modulated by linoleic acids or their metabolites and probably there is an inverse relationship between ACMSD activity and the production of quinolinic acid converted from tryptophan.
Egashira
Yukari
Y
Laboratory of Food and Nutrition, Department of Bioproduction Science, Chiba University, Matsudo, Chiba 271-8510, Japan. egashira@midori.chiba-u.ac.jp
Sato
Makiko
M
Tanabe
Atsushi
A
Saito
Kuniaki
K
Fujigaki
Suwako
S
Sanada
Hiroo
H
D000818:Animals; D004042:Dietary Fats, Unsaturated / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects; D019787:Linoleic Acid / Q000494:pharmacology*; D008099:Liver / Q000187:drug effects* / Q000201:enzymology*; D017378:Quinolinic Acid / Q000097:blood*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats
D004042:Dietary Fats, Unsaturated; D012333:RNA, Messenger; D019787:Linoleic Acid; D017378:Quinolinic Acid