Engineering microglial exosome-mediated microRNA-124-3p delivery for Alzheimer's disease combinational therapy

Area of Science:

• Neuroscience
• Biomedical Engineering
• Molecular Biology

Background:

• Alzheimer's disease (AD) treatment is hindered by single-target therapies and challenges in delivering drugs across the blood-brain barrier (BBB).
• MicroRNA-124-3p (miR-124-3p) shows therapeutic potential for AD, but its delivery to the brain is problematic due to the BBB and instability.

Purpose of the Study:

• To engineer a novel nanomedicine for effective delivery of miR-124-3p to AD-affected brain regions.
• To develop a multifunctional therapeutic approach for Alzheimer's disease using biomimetic nanomedicine.

Main Methods:

• Engineered microglial exosomes enriched with miR-124-3p (Exo-124-3p) for enhanced BBB penetration and microglia targeting.
• Assessed the therapeutic effects of Exo-124-3p on amyloid-beta (Aβ) plaque aggregation, neuroinflammation, and cognitive function in an AD mouse model.
• Investigated the mechanism of action, focusing on the inhibition of the MEKK3/NF-κB signaling pathway.

Main Results:

• Exo-124-3p successfully traversed the BBB and targeted activated microglia.
• Treatment with Exo-124-3p reduced Aβ plaque aggregation, attenuated microglial and astrocyte activation, and demonstrated neuroprotective effects.
• Significant improvement in cognitive function was observed in the AD mouse model treated with Exo-124-3p.
• Exo-124-3p inhibited the MEKK3/NF-κB pathway, ameliorating neuroinflammation.

Conclusions:

• Engineered Exo-124-3p represents a promising biomimetic nanomedicine for multifunctional Alzheimer's disease treatment.
• This approach offers a viable strategy for overcoming BBB delivery challenges for miRNA therapeutics in brain diseases.
• The study provides a new avenue for combinational therapy and miRNA delivery systems for neurological disorders.