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Updated: May 6, 2026
Isolation and Flow Cytometric Analysis of Immune Cells from the Ischemic Mouse Brain
Published on: February 12, 2016
M2 macrophage-derived exosomes mitigate acute inflammation following ischemic stroke
Jinyang Song1, Gang Su2, Wei Chen1
1The Second Hospital & Clinical Medical School, Lanzhou University, Lanzhou, Gansu, China.
Background:
The acute inflammatory response following ischemic stroke is a key factor in exacerbating brain injury. Modulating excessive inflammation during the oxidative stress (OS) phase represents a potential therapeutic strategy; however, clinical interventions remain limited.
Methods:
M0 and M2 macrophage-derived exosomes (M0-exo and M2-exo) were administered to microglia under oxygen-glucose deprivation/reperfusion (OGD/R) conditions and to mice subjected to transient middle cerebral artery occlusion (tMCAO). The mechanisms underlying their anti-inflammatory effects were then investigated through a combination of bioinformatic analysis and fundamental experiments.
Results:
Treatment with exosomes markedly suppressed the expression of pro-inflammatory factors. Furthermore, they significantly reduced cerebral infarct volume and improved neurological function in mice. Notably, the anti-inflammatory effect of M2-exo was significantly superior to that of M0-exo. miRNA sequencing and subsequent validation revealed a specific enrichment of miR-330-5p in M2-exo. Mechanistic studies have demonstrated that miR-330-5p suppresses the expression of Spleen tyrosine kinase (Syk) and signal transducer and activator of transcription 3 (Stat3) in microglia, consequently reducing the production of downstream inflammatory factors. Treatment with Syk or Stat3 inhibitors partially mimicked the anti-inflammatory action of miR-330-5p in rescue studies.
Conclusion:
Our results unveil a novel anti-inflammatory pathway mediated by M2-exo, providing novel insights for stroke therapy.
Insights
M2 macrophage-derived exosomes (M2-exo) show potent anti-inflammatory effects, reducing brain injury after stroke. They deliver miR-330-5p, which targets Syk and Stat3 pathways, offering a novel therapeutic strategy for ischemic stroke.
Area of Science:
- Neuroscience
- Immunology
- Biochemistry
Background:
- Ischemic stroke triggers acute inflammation, worsening brain damage.
- Oxidative stress during stroke exacerbates injury, with limited therapeutic options.
- Targeting neuroinflammation is a key strategy for stroke treatment.
Purpose of the Study:
- To investigate the therapeutic potential of macrophage-derived exosomes in ischemic stroke.
- To elucidate the anti-inflammatory mechanisms of M2 macrophage-derived exosomes (M2-exo).
- To identify key molecular players involved in the therapeutic effects of M2-exo.
Main Methods:
- Exosomes from M0 and M2 macrophages were administered to microglia and mice models of ischemic stroke (tMCAO).
- Bioinformatic analysis and experimental validation were used to explore anti-inflammatory mechanisms.
- miRNA sequencing identified specific microRNAs enriched in M2-exo.
Main Results:
- Exosome treatment significantly suppressed pro-inflammatory factors and reduced infarct volume.
- M2-exo demonstrated superior anti-inflammatory effects compared to M0-exo.
- miR-330-5p in M2-exo was found to suppress Syk and Stat3 signaling in microglia, reducing inflammation.
Conclusions:
- M2-exo exert significant anti-inflammatory effects in ischemic stroke models.
- The miR-330-5p/Syk/Stat3 pathway represents a novel therapeutic target for stroke.
- Macrophage-derived exosomes offer promising therapeutic insights for stroke treatment.
