miR-429-3p mediates memory decline by targeting MKP-1 to reduce surface GluA1-containing AMPA receptors in a mouse model of Alzheimer's disease

A novel carbamate-based hybrid derivative with anti-neuroinflammatory properties as a selective butyrylcholinesterase inhibitor for Alzheimer's disease therapy

Cholinesterase inhibitors (ChEIs) are widely utilized for the symptomatic management of Alzheimer's disease (AD) by enhancing acetylcholine levels to improve cognitive function. Concurrently, neuroinflammation has emerged as a critical factor in AD progression, necessitating therapies that address this pathology. In this study, we designed and synthesized a novel bifunctional cholinesterase inhibitor, (E)-4-(2-(3-(benzyloxy)-4-oxo-4H-pyran-2-yl) vinyl)-1,2-phenylene bis(ethyl(methyl)carbamate) (D40), which combines potent cholinesterase inhibition with robust anti-neuroinflammatory activity. D40 demonstrated potent inhibition of human butyrylcholinesterase (hBuChE), with an IC₅₀ value of 0.59 ± 0.03 μM, significantly outperforming Rivastigmine (IC₅₀ = 3.70 ± 0.96 μM). Molecular docking and molecular dynamics simulations confirmed a stable and selective binding of D40 to the BuChE active site, underpinning its inhibitory profile. Additionally, D40 exhibited strong anti-inflammatory effects, with an IC₅₀ value of 4.55 ± 0.78 μM for suppressing nitric oxide production and demonstrated excellent blood-brain barrier permeability. In vivo studies in aged 5 × FAD mice revealed that D40 significantly reduced neuroinflammation by suppressing pro-inflammatory cytokines and glial activation. Furthermore, D40 mitigated Aβ deposition, promoted neuronal survival, and improved cognitive deficits, while demonstrating a favorable safety profile in acute toxicity evaluations. These findings highlight D40 as a dual-function ChEI capable of providing symptomatic relief and modulating neuroinflammatory pathways associated with AD. With its enhanced cholinesterase inhibition and anti-inflammatory properties, D40 emerges as a promising candidate for the treatment of advanced stages of AD. Acetylcholine deficiency and neuroinflammation as drivers of Alzheimer's disease dually intervened by Compound D40.

KIF9 Ameliorates Neuropathology and Cognitive Dysfunction by Promoting Macroautophagy in a Mouse Model of Alzheimer's Disease

Alzheimer's disease (AD) is a prevalent neurodegenerative disorder affecting the elderly. The imbalance of protein production and degradation processes leads to the accumulation of misfolded and abnormally aggregated amyloid-beta (Aβ) in the extracellular space and forms senile plaques, which constitute one of the most critical pathological hallmarks of AD. KIF9, a member of the kinesin protein superfamily, mediates the anterograde transport of intracellular cargo along microtubules. However, the exact role of KIF9 in AD pathogenesis remains largely elusive. In this study, we reported that the expression of kinesin family member 9 (KIF9) in the hippocampus of APP23/PS45 double-transgenic AD model mice declined in an age-dependent manner, concurrent with macroautophagy dysfunction. Furthermore, we found that KIF9 mediated the transport of lysosomes through kinesin light chain 1 (KLC1), thereby participating in the degradation of amyloidogenic pathway-related proteins of Aβ precursor protein (APP) in AD model cells through promoting the macroautophagy pathway. Importantly, genetic upregulation of KIF9 via adeno-associated virus (AAV) diminished Aβ deposition and alleviated cognitive impairments in AD model mice by enhancing macroautophagy function. Collectively, our findings underscore the ability of KIF9 to promote macroautophagy through KLC1-mediated anterograde transport of lysosomes, effectively ameliorating cognitive dysfunction in AD model mice. These discoveries suggest that KIF9 may represent a novel therapeutic target for the treatment of AD.

ELK1 inhibition alleviates amyloid pathology and memory decline by promoting the SYVN1-mediated ubiquitination and degradation of PS1 in Alzheimer's disease

ELK1 is a member of the E-twenty-six transcription factor family and is usually activated by phosphorylation at Ser383 and Ser389 by extracellular signal-regulated kinase 1/2 (ERK1/2). Dysregulation of ERK1/2 is involved in Alzheimer's disease (AD)-related neuropathogenesis and cognitive impairments. However, the role of ELK1 in AD pathogenesis remains unclear. Here we report that the expression of ELK1 was significantly increased in the brain tissues of patients with AD and AD model mice. The genetic knockdown of ELK1 or inhibition of its phosphorylation by an interfering peptide (TAT-DEF-ELK1 (TDE)) reduced amyloidogenic processing of APP by targeting PS1, consequently inhibiting Aβ generation and alleviating synaptic and memory impairments in APP23/PS45 double-transgenic AD model mice. In addition, we further found that ELK1 regulated the expression of PS1 by competitively inhibiting the interaction between PS1 and its E3 ubiquitin ligase synoviolin (SYVN1), thereby inhibiting the SYVN1-mediated ubiquitination and degradation of PS1. Our results demonstrate that ELK1 aberrantly increases in AD and genetic or pharmacological inhibition of ELK1 can alleviate AD-related pathology and memory impairments by enhancing the SYVN1-mediated PS1 ubiquitination and degradation, indicating that ELK1 may be a novel target for AD treatment.

GALM Alleviates Aβ Pathology and Cognitive Deficit Through Increasing ADAM10 Maturation in a Mouse Model of Alzheimer's Disease

Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder worldwide, causing dementia and affecting millions of individuals. One prominent characteristic in the brains of AD patients is glucose hypometabolism. In the context of galactose metabolism, intracellular glucose levels are heightened. Galactose mutarotase (GALM) plays a crucial role in maintaining normal galactose metabolism by catalyzing the conversion of β-D-galactose into α-D-galactose (α-D-G). The latter is then converted into glucose-6-phosphate, improving glucose metabolism levels. However, the involvement of GALM in AD progression is still unclear. In the present study, we found that the expression of GALM was significantly increased in AD patients and model mice. Genetic knockdown of GALM using adeno-associated virus did not change the expression of amyloid precursor protein (APP) and APP-cleaving enzymes including a disintegrin and metalloprotease 10 (ADAM10), β-site APP-cleaving enzyme 1 (BACE1), and presenilin-1 (PS1). Interestingly, genetic overexpression of GALM reduced APP and Aβ deposition by increasing the maturation of ADAM10, although it did not alter the expression of BACE1 and PS1. Further electrophysiological and behavioral experiments showed that GALM overexpression significantly ameliorated the deficits in hippocampal CA1 long-term potentiation (LTP) and spatial learning and memory in AD model mice. Importantly, direct α-D-G (20 mg/kg, i.p.) also inhibited Aβ deposition by increasing the maturation of ADAM10, thereby improving hippocampal CA1 LTP and spatial learning and memory in AD model mice. Taken together, our results indicate that GALM shifts APP processing towards α-cleavage, preventing Aβ generation by increasing the level of mature ADAM10. These findings indicate that GALM may be a potential therapeutic target for AD, and α-D-G has the potential to be used as a dietary supplement for the prevention and treatment of AD.

APP lysine 612 lactylation ameliorates amyloid pathology and memory decline in Alzheimer's disease

Posttranslational modification (PTM) of the amyloid precursor protein (APP) plays a critical role in Alzheimer's disease (AD). Recent evidence reveals that lactylation modification, as a novel PTM, is implicated in the occurrence and development of AD. However, whether and how APP lactylation contributes to both the pathogenesis and cognitive function in AD remains unknown. Here, we observed a reduction in APP lactylation in AD patients and AD model mice and cells. Proteomic mass spectrometry analysis further identified lysine 612 (APP-K612la) as a crucial site for APP lactylation, influencing APP amyloidogenic processing. A lactyl-mimicking mutant (APPK612T) reduced amyloid-β peptide (Aβ) generation and slowed down cognitive deficits in vivo. Mechanistically, APPK612T appeared to facilitate APP trafficking and metabolism. However, lactylated APP entering the endosome inhibited its binding to BACE1, suppressing subsequent cleavage. Instead, it promoted protein interaction between APP and CD2-associated protein (CD2AP), thereby accelerating the endosomal-lysosomal degradation pathway of APP. In the APP23/PS45 double-transgenic mouse model of AD, APP-Kla was susceptible to L-lactate regulation, which reduced Aβ pathology and repaired spatial learning and memory deficits. Thus, these findings suggest that targeting APP lactylation may be a promising therapeutic strategy for AD in humans.