Aβ-AGE aggravates cognitive deficit in rats via RAGE pathway

Area of Science:

• Neuroscience
• Biochemistry
• Pathology

Background:

• Beta-amyloid (Aβ) accumulation is central to Alzheimer's disease (AD) pathogenesis.
• The precise mechanisms driving Aβ toxicity in AD brains remain incompletely understood.
• Previous in vitro studies indicated glycated Aβ (Aβ-AGE) enhances Aβ neurotoxicity.

Purpose of the Study:

• To investigate the in vivo role and mechanism of Aβ-AGE in Alzheimer's disease.
• To determine if Aβ-AGE exacerbates Aβ-induced cognitive deficits and associated neuropathology.
• To explore the involvement of the receptor for advanced glycation endproducts (RAGE) pathway.

Main Methods:

• Aβ-AGE was synthesized in vitro and stereotactically injected into rat brains.
• Cognitive function was assessed, alongside measurements of long-term potentiation (LTP) and dendritic spine density.
• Expression of RAGE and downstream signaling molecules (GSK3, NF-κB, p38) was analyzed.
• The effects of RAGE antibody and a GSK3 inhibitor were evaluated.

Main Results:

• Aβ-AGE injection significantly worsened Aβ-induced cognitive impairment in rats.
• Accelerated LTP deterioration, reduced dendritic spine density, and decreased synaptic proteins were observed.
• Upregulation of RAGE and activation of downstream GSK3, NF-κB, and p38 were detected.
• RAGE antibody or GSK3 inhibition mitigated the cognitive decline induced by Aβ-AGE.

Conclusions:

• In vivo, Aβ-AGE exhibits greater toxicity than native Aβ.
• Aβ-AGE exacerbates AD-like pathology via the RAGE-mediated pathway.
• Aβ-AGE and RAGE represent potential therapeutic targets for Alzheimer's disease.