O-GlcNAcylation regulates extracellular signal-regulated kinase (ERK) activation in Alzheimer’s disease

Frontiers in Aging Neuroscience

Neuroscience

Margaret A. Johnston¹  Jenna Shawa¹  Sophiya John Ephrame¹  Marisa S. Carman¹  Amy Qiang¹  Halyna Fedosyuk¹  Ibtihal Alghusen¹  Gentry K. Cork¹  Aspin R. Denson¹  Russell H. Swerdlow²  Chad Slawson³  Victoria Marshall⁴ 

[1] Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, United States;Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, United States;Department of Neurology, University of Kansas Medical Center, Kansas City, KS, United States;University of Kansas Alzheimer’s Disease Research Center, University of Kansas Medical Center, Kansas City, KS, United States;Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, United States;University of Kansas Alzheimer’s Disease Research Center, University of Kansas Medical Center, Kansas City, KS, United States;School of Medicine, University of Kansas Medical Center, Kansas City, KS, United States;

关键词: O-GlcNAc;    OGT;    OGA;    ERK;    APP;    Alzheimer’s disease;    Thiamet-G;   

DOI  :  10.3389/fnagi.2023.1155630

 received in 2023-01-31, accepted in 2023-06-13,  发布年份 2023

来源: Frontiers

【 摘 要 】

IntroductionAberrant activation of Extracellular Signal-Regulated Kinase (ERK) signaling is associated with Alzheimer’s disease (AD) pathogenesis. For example, enhanced ERK signal activation mediated by Apolipoprotein E4 (APOE4), which is a critical genetic risk factor for AD, increases the transcription of amyloid precursor protein (APP). We hypothesize that O-linked N-acetylglucosamine (O-GlcNAc) regulates the phosphorylation and activation of ERK. O-GlcNAc is a single sugar post-translational modification that dynamically cycles on and off proteins in response to nutrient changes by the action of the enzymes O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), respectively. However, O-GlcNAc quickly returns to a baseline level after stimulus removal (called O-GlcNAc homeostasis).MethodsWe did a serum reactivation time-course followed by western blot in SH-SY5Y neuroblastoma cells after long-term O-GlcNAcase (OGA) inhibition by Thiamet-G (TMG) treatment, O-GlcNAc transferase (OGT) knock-down (KD) and OGA KD. Brain tissues of C57BL6/J mice and 5XFAD Alzheimer’s disease mice intra-peritoneally injected with TMG for 1 month and C57BL6/J mice intra-peritoneally injected with TMG for 6 months were also used for western blot.ResultsWe found that ERK1/2 phosphorylation at Thr 202/Tyr204 and Thr183/Tyr185 (p-ERK) are amplified and hence ERK1/2 are activated after long-term OGA inhibition in SH-SY5Y cells. In addition to pharmacological treatment, genetic disruption of O-GlcNAc by OGT KD and OGA KD also increased p-ERK in SH-SY5Y cells suggesting O-GlcNAc homeostasis controls ERK signaling. To determine how O-GlcNAc regulates p-ERK, we probed the expression of phosphorylated mitogen-activated protein kinase-kinase (p-MEK) which phosphorylates and activates ERK and Dual specificity phosphatase-4 (DUSP4) which dephosphorylates and inactivates ERK in SH-SY5Y cells. p-MEK increases in TMG treated and OGT KD cells whereas total DUSP4 decreases in OGT KD and OGA KD cells with serum reactivation time course. Next, we probed the role of OGA inhibition in regulating ERK activation using mice brain-tissue samples. Interestingly, 6-month intra-peritoneal TMG injection in C57BL/6J mice showed an increase in amplitude of p-ERK and APP protein levels, indicating long-term OGA inhibition potentially contributes to AD progression. Furthermore, 1-month TMG injection was sufficient to increase the amplitude of p-ERK in 5XFAD AD mice brains suggesting AD phenotype contributes to the acceleration of ERK activation mediated by OGA inhibition.ConclusionTogether, these results indicate that disruptions to O-GlcNAc homeostasis amplify ERK signal activation in AD.

【 授权许可】

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Copyright © 2023 Ephrame, Cork, Marshall, Johnston, Shawa, Alghusen, Qiang, Denson, Carman, Fedosyuk, Swerdlow and Slawson.