Mesenchymal Stem Cell-Derived Exosomes Improved Cerebral Infarction via Transferring miR-23a-3p to Activate Microglia

Area of Science:

• Neuroscience
• Regenerative Medicine
• Molecular Biology

Background:

• Cerebral infarction (CI) poses a significant health challenge with limited treatment options.
• Mesenchymal stem cells-derived exosomes (MSCs-exo) are emerging as a potential therapeutic strategy for CI.
• Understanding the molecular mechanisms underlying MSCs-exo's therapeutic effects is crucial for optimizing CI treatment.

Purpose of the Study:

• To investigate the role of miR-23a-3p within MSCs-exo in the treatment of cerebral infarction (CI).
• To elucidate the mechanism by which MSCs-exo influences microglia polarization and inflammatory responses in CI models.
• To determine if MSCs-exo-mediated CI treatment is dependent on miR-23a-3p delivery.

Main Methods:

• Western blot and qRT-PCR were used to assess protein and gene expression.
• Neurological deficit scores and TTC staining evaluated brain injury in middle cerebral artery occlusion (MCAO) rat models.
• Immunohistochemistry, flow cytometry, and ELISA were employed to analyze microglia activation, polarization, and inflammatory cytokine levels.

Main Results:

• MSCs-exo, particularly those derived from bone marrow (BMSCs-exo), improved neuronal function and reduced infarct size in MCAO rats.
• miR-23a-3p was found to be upregulated in MSCs-exo.
• Knockdown of miR-23a-3p in BMSCs-exo reversed the therapeutic benefits, indicating its critical role in inhibiting MCAO-induced microglia activation and M1 polarization.

Conclusions:

• MSCs-exo exerts therapeutic effects on cerebral infarction (CI) by transferring miR-23a-3p.
• miR-23a-3p within MSCs-exo promotes microglia deactivation and M2 polarization, thereby reducing neuroinflammation.
• This study reveals a novel regulatory mechanism of MSCs-exo in CI treatment, highlighting miR-23a-3p as a key mediator.