M2 microglia-derived small extracellular vesicles modulate NSC fate after ischemic stroke via

Qian Zhang1,2, Yan Yi3,2, Tiange Chen1,2

  • 1Department of Neurosurgery, Xiangya Hospital Central South University, Changsha, Hunan, CN, 410008, China.

PubMed
Abstract

Insights

M2 microglia-derived small extracellular vesicles (M2-sEVs) promote neural stem cell neurogenesis and stroke recovery. They deliver specific microRNAs to downregulate key genes, enhancing therapeutic potential for ischemic stroke.

Area of Science:

  • Neuroscience
  • Regenerative Medicine
  • Cell Biology

Background:

  • Endogenous neurogenesis aids stroke recovery.
  • Anti-inflammatory M2 microglia can enhance neural stem cell (NSC)-mediated neurogenesis after ischemic stroke (IS).
  • Mechanisms of M2 microglia influencing NSC neurogenesis post-IS are unclear, but M2 microglia-derived small extracellular vesicles (M2-sEVs) show potential.

Purpose of the Study:

  • To investigate the role of M2-sEVs in NSC-mediated neurogenesis and functional recovery post-IS.
  • To elucidate the underlying molecular mechanisms involving microRNAs within M2-sEVs.

Main Methods:

  • Isolated M2-sEVs from IL-4-stimulated microglia.
  • Administered M2-sEVs intravenously to mice post-transient Middle Cerebral Artery Occlusion (tMCAO).
  • Assessed infarct volume, neurological function, NSC proliferation/migration/differentiation in vivo and in vitro, and performed microRNA sequencing on M2-sEVs.

Main Results:

  • M2-sEVs reduced infarct volume and improved neurological scores in mice post-tMCAO.
  • M2-sEV treatment promoted NSC proliferation and neuronal differentiation both in vivo and in vitro.
  • M2-sEVs were enriched with miR-93-5p and miR-25-3p, which downregulated TGFBR, PTEN, and FOXO3 in NSCs, reversing beneficial effects when inhibited.

Conclusions:

  • M2-sEVs enhance NSC proliferation and neuronal differentiation, offering protection against ischemic stroke.
  • The therapeutic effects are partly mediated by miR-25-3p and miR-93-5p delivery, which downregulate TGFBR, PTEN, and FOXO3 expression in NSCs.