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The action of vitamin K in brain during aging is linked to the pAKT/AKT signaling pathway
Author(s) -
Guylaine Ferland,
Mabit Alexandra,
Fournier Chantal,
Letourneau Jacynthe
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.533.2
Subject(s) - protein kinase b , striatum , endocrinology , hippocampus , medicine , morris water navigation task , apoptosis , western blot , biology , caspase 3 , cortex (anatomy) , chemistry , programmed cell death , neuroscience , biochemistry , dopamine , gene
Vitamin K (VK) participates in brain function through sphingolipid metabolism and activation of protein Gas6. We have provided evidence that long‐term low phylloquinone (K 1 ) intake leads to cognitive deficits in aging rats and to a concurrent accumulation of ceramides in certain brain regions. To gain further insight on these findings, we investigated the pAKT/AKT cell signaling and caspase‐3 apoptotic processes in 20 mo‐old female SD rats which had been fed diets containing either very low (VL: 80), low (L: 500) and moderately high (H: 2000) levels of K 1 (μg/Kg diet; n=5/group). A fourth group fed the L diet until 14 mo and the H diet until sacrifice was also investigated. The pAKT/AKT ratio (western blot) and caspase‐3 activity (enzymatic assay) which reflect cell survival and cell death respectively, were assessed in pons medulla, frontal cortex, striatum and hippocampus. Strong trends were observed for higher cell survival in the striatum and frontal cortex of rats from the H group. Furthermore, when VK was fed in limited amounts (groups VL and L), pAKT/AKT ratios were higher in the hippocampus than in the other regions. In contrast, caspase‐3 activity was more heterogenous, a finding which may be linked to the assay used. In conclusion, long‐term consumption of a VK rich diet appears to offer cellular protection in brain and could contribute to the maintenance of cognitive functions during aging. Supported by CIHR.