Plasmalogen metabolism-related enzymes in rat brain during aging: influence of n-3 fatty acid intake

Autor: Agnès André, Pierre Juanéda, Jean Michel Chardigny, Jean Louis Sébédio
Přispěvatelé: FLAveur, VIsion et Comportement du consommateur (FLAVIC), Etablissement National d'Enseignement Supérieur Agronomique de Dijon (ENESAD)-Institut National de la Recherche Agronomique (INRA)-Université de Bourgogne (UB)
Rok vydání: 2006
Předmět:
Zdroj: Biochimie
Biochimie, Elsevier, 2006, 88 (1), pp.103-111. ⟨10.1016/j.biochi.2005.06.010⟩
ISSN: 0300-9084
Popis: Plasmalogens (Pls) are phospholipids containing a vinyl–ether bond at the sn -1 position of the glycerol backbone. They represent between 1/2 and 2/3 of the ethanolamine phospholipids in the brain. During aging, the Pls content in human brain falls down. However, the role of Pls metabolism-related enzymes in the regulation of Pls levels remains to be determined. Dihydroxyacetone phosphate acyltransferase (DHAP-AT) is the enzyme involved in the first step of Pls biosynthesis. In the brain, a phospholipase A 2 , which selectively acts on Pls, has been isolated (Pls-PLA 2 s). In this work, we aimed to evaluate the impact of DHAP-AT (a key enzyme of Pls biosynthesis) and Pls-PLA 2 (a specific Pls degradation enzyme) on the evolution of Pls content in the rat brain during aging. The influence of n-3 fatty acid intake was also evaluated. Littermates from two generations of n-3 deficient rats were fed an equilibrated diet containing either α-LNA alone or with two doses of DHA. After weaning, 3, 9 or 21 months of diet, rats were sacrificed. Enzymatic assays were performed, Pls levels were assessed and the sn -2 position of ethanolamine Pls was analyzed. DHAP-AT activity significantly increased between weaning and 3 months with a concomitant increase of brain Pls, which reached maximal levels after 9 months. Then, Pls levels and DHAP-AT activity significantly decreased while Pls-PLA 2 s activity significantly increased. Dietary n-3 fatty acids had no effect on DHAP-AT activity and on Pls levels. In conclusion, the increase of brain Pls content in the first part of the life may be related to the high increase of DHAP-AT activity, probably stimulated by DHA. In aged animals, the decrease of Pls levels may mainly be caused to an increase of their degradation by Pls-PLA 2 . Dietary DHA may not oppose the physiologic aging.
Databáze: OpenAIRE
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