The age-dependent deposition of amyloid-β peptides, derived from amyloid precursor protein (APP), is a neuropathological hallmark of Alzheimer's disease (AD). Despite age being the greatest risk factor for AD, the molecular mechanisms linking ageing to APP processing are unknown. Here we show that asparagine endopeptidase (AEP), a pH-controlled cysteine proteinase, is activated during ageing and mediates APP proteolytic processing. AEP cleaves APP at N373 and N585 residues, selectively influencing the amyloidogenic fragmentation of APP. AEP is activated in normal mice in an age-dependent manner, and is strongly activated in 5XFAD transgenic mouse model and human AD brains. Deletion of AEP from 5XFAD or APP/PS1 mice decreases senile plaque formation, ameliorates synapse loss, elevates long-term potentiation and protects memory. Blockade of APP cleavage by AEP in mice alleviates pathological and behavioural deficits. Thus, AEP acts as a δ-secretase, contributing to the age-dependent pathogenic mechanisms in AD.
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http://dx.doi.org/10.1038/ncomms9762 | DOI Listing |
J Alzheimers Dis
January 2025
Key Laboratory of Basic Pharmacology of Guizhou Province, School of Pharmacy, Zunyi Medical University, Zunyi, China.
Background: One of the hallmark pathological characteristics of Alzheimer's disease (AD) is amyloid-β (Aβ) accumulated in brain, which is mainly derived from the proteolytic processing of amyloid-β protein precursor (AβPP). The ubiquitin-proteasome system is able to reduce Aβ generation by ubiquitination and degradation of AβPP. Icariin (ICA), a flavonoid isolated from Maxim.
View Article and Find Full Text PDFAutophagy
January 2025
Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Department of Neurology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China.
Although the relationship between macroautophagy/autophagy and Alzheimer disease (AD) is widely studied, the underlying mechanisms are poorly understood, especially the regulatory role of the initiation signaling of autophagy on AD. Here, we find that the ER transmembrane protein CANX (calnexin) is a novel interaction partner of the autophagy-inducing kinase ULK1 and is required for ULK1 recruitment to the ER under basal or starved conditions. Loss of CANX results in the inactivity of ULK1 kinase and inhibits autophagy flux.
View Article and Find Full Text PDFAlzheimer's disease (AD) is the most prevalent neurodegenerative dementia, marked by progressive cognitive decline and memory impairment. Despite advances in therapeutic research, single-target-directed treatments often fall short in addressing the complex, multifactorial nature of AD. This arises from various pathological features, including amyloid-β (Aβ) aggregate deposition, metal ion dysregulation, oxidative stress, impaired neurotransmission, neuroinflammation, mitochondrial dysfunction, and neuronal cell death.
View Article and Find Full Text PDFACS Chem Neurosci
January 2025
Department of Health Service, Polyclinic, Sector 6, Jhajjar, Haryana 124103, India.
Alzheimer's disease (AD) impacts millions of elderly adults worldwide causing cognitive decline and severe deterioration of activities of daily life. The popular causal hypotheses for several decades include beta-amyloid (Aβ) deposition and tau hyperphosphorylation. AD research and more than 34% of clinical trials in AD are based on these two hypotheses.
View Article and Find Full Text PDFAm J Physiol Cell Physiol
January 2025
School of Health and Exercise Sciences, The University of British Columbia, Okanagan,BC V1V 1V7, Canada.
People with type 2 diabetes (T2D) have a greater risk of developing neurodegenerative diseases, like Alzheimer's disease, in later life. Exogenous ketone supplements containing the ketone body β-hydroxybutyrate (β-OHB) may be a strategy to protect the brain as β-OHB can support cerebral metabolism and promote neuronal plasticity via expression of brain-derived neurotrophic factor (BDNF). Parallel human (ClinicalTrials.
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