Berberine Reduces Aβ₄₂ Deposition and Tau Hyperphosphorylation via Ameliorating Endoplasmic Reticulum Stress

Area of Science:

• Neuroscience
• Pharmacology
• Molecular Biology

Background:

• Alzheimer's disease (AD) is linked to endoplasmic reticulum (ER) stress, which worsens senile plaques and neurofibrillary tangles.
• Berberine, a natural compound, shows promise for treating AD.

Purpose of the Study:

• To investigate berberine's effects on ER stress and cognitive impairment in a mouse model of Alzheimer's disease.
• To elucidate the molecular mechanisms by which berberine ameliorates AD pathology.

Main Methods:

• Utilized APP/PS1 mice to model Alzheimer's disease.
• Investigated the role of ER stress, glycogen synthase kinase 3β (GSK3β), PRKR-like endoplasmic reticulum kinase (PERK), eukaryotic translation initiation factor-2 α (eIF2α), and beta-site APP cleaving enzyme-1 (BACE1) signaling.
• Employed siRNA targeting eIF2α to validate its role in amyloid beta (Aβ) production.

Main Results:

• Berberine ameliorated ER stress and cognitive deficits in APP/PS1 mice.
• ER stress was identified as a central signaling hub, involving GSK3β-mediated tau phosphorylation and PERK/eIF2α pathway activation.
• Berberine inhibited GSK3β activity, reducing tau phosphorylation and suppressed Aβ₄₂ production by inhibiting the PERK/eIF2α/BACE1 pathway.

Conclusions:

• Berberine demonstrates potential in ameliorating Alzheimer's disease pathology by suppressing ER stress.
• Berberine's mechanism involves downregulating tau phosphorylation and Aβ₄₂ production via the PERK/eIF2α/BACE1 pathway.
• This study provides insights into pharmacological interventions for AD and identifies potential drug development targets.