High-fat diet–induced activation of SGK1 promotes Alzheimer's disease–associated tau pathology. Issue 18 (22nd April 2021)

• Record Type: Journal Article
• Authors: Elahi, Montasir; Motoi, Yumiko; Shimonaka, Shotaro; Ishida, Yoko; Hioki, Hiroyuki; Takanashi, Masashi; Ishiguro, Koichi; Imai, Yuzuru; Hattori, Nobutaka
• Is Part Of: Human molecular genetics. Volume 30:Issue 18(2021)
• Page Start: 1693
• Page End: 1710
• Publication Date: 2021-04-22
• Subjects: Human molecular genetics -- Periodicals; Human chromosome abnormalities -- Periodicals; 572.8
• DOI: 10.1093/hmg/ddab115
• Languages: English
• ISSNs: 0964-6906

Abstract

Abstract: Type 2 diabetes mellitus (T2DM) has long been considered a risk factor for Alzheimer's disease (AD). However, the molecular links between T2DM and AD remain obscure. Here, we reported that serum-/glucocorticoid-regulated kinase 1 (SGK1) is activated by administering a chronic high-fat diet (HFD), which increases the risk of T2DM, and thus promotes Tau pathology via the phosphorylation of tau at Ser214 and the activation of a key tau kinase, namely, GSK-3ß, forming SGK1-GSK-3ß-tau complex. SGK1 was activated under conditions of elevated glucocorticoid and hyperglycemia associated with HFD, but not of fatty acid–mediated insulin resistance. Elevated expression of SGK1 in the mouse hippocampus led to neurodegeneration and impairments in learning and memory. Upregulation and activation of SGK1, SGK1-GSK-3ß-tau complex were also observed in the hippocampi of AD cases. Our results suggest that SGK1 is a key modifier of tau pathology in AD, linking AD to corticosteroid effects and T2DM.