Quercetin reduces eIF2α phosphorylation by GADD34 induction
| Autor: | Kazunori Ohta, Kaori Ohzawa, Saiful Islam, Masuko Kobori, Miao-xing Wang, Takashi Inuzuka, Emika Nishida, Toshiyuki Nakagawa, Miki Hayakawa, Masashi Ueda, Chihiro Suzuki, Shimo Li, Masanori Itoh |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
Aging
medicine.medical_specialty Conditioning Classical Mice Transgenic Biology Presenilin Antioxidants Autophagy-Related Protein 5 Dephosphorylation Amyloid beta-Protein Precursor Mice Alzheimer Disease Internal medicine Protein Phosphatase 1 medicine Presenilin-1 Initiation factor Animals Humans Phosphorylation Amyloid beta-Peptides General Neuroscience Endoplasmic reticulum Autophagy ATF4 Brain Translation (biology) Activating Transcription Factor 4 Peptide Fragments DNA-Binding Proteins Mice Inbred C57BL Disease Models Animal Endocrinology HEK293 Cells Biochemistry Gene Expression Regulation Receptors Leptin Quercetin Neurology (clinical) Geriatrics and Gerontology Microtubule-Associated Proteins Developmental Biology Transcription Factors |
| Zdroj: | Neurobiology of aging. 36(9) |
| ISSN: | 1558-1497 |
| Popis: | The production of amyloid β (Aβ) in the brain from Aβ precursor protein (APP) through γ-secretase is important for the pathogenesis of Alzheimer's disease (AD). Our previous studies have demonstrated that autophagy impairment and endoplasmic reticulum stress increase presenilin 1 expression and enhance γ-secretase activity through the phosphorylation of eukaryotic translation initiation factor 2α (eIF2α) and the translation of activating transcription factor 4 (ATF4). However, the inhibitory molecules for γ-secretase are largely unknown. Here, we demonstrate that the levels of ATF4 expression are increased in the brain of APP23 AD model mice; furthermore, these levels enhanced in the brain of APP23 mice crossed with obese and diabetic db/db (Leprdb/db) mice. A polyhydroxylated flavonoid, quercetin, suppressed presenilin 1 expression and Aβ secretion in autophagy-impaired cells by the induction of growth arrest and DNA damaged-inducible gene (GADD) 34, which mediates eIF2α dephosphorylation, leading to decreased ATF4 expression. GADD34 induction was observed in the brain of wild-type mice, and APP23 mice fed quercetin in their diet. After the long-term feeding of quercetin, deterioration in memory assessed by freezing behavior was delayed in APP23 mice. These results indicate that quercetin may reduce eIF2α phosphorylation and ATF4 expression through GADD34 induction in the brain, leading to the improvement of memory in aged mice and the delay of deterioration in memory at the early stage of AD in AD model mice. |
| Databáze: | OpenAIRE |
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