Avicularin Treatment Ameliorates Ischemic Stroke Damage by Regulating Microglia Polarization and its Exosomes via the NLRP3 Pathway

  • J Integr Neurosci. 2024 Oct 30;23(11):196. doi: 10.31083/j.jin2311196.
Yan Shi  1 ,  Yufeng Yang  2 ,  Juntong Liu  3 ,  Jinling Zheng  4
Affiliations
  • 1. Key Laboratory of Ministry of Education for TCM Viscera-State Theory and Applications, Liaoning University of Traditional Chinese Medicine, 110032 Shenyang, Liaoning, China.
  • 2. Department of Traditional Chinese Medicine, Liaoning University of Traditional Chinese Medicine, 110032 Shenyang, Liaoning, China.
  • 3. Teaching and Experiment Center, Liaoning University of Traditional Chinese Medicine, 110032 Shenyang, Liaoning, China.
  • 4. Department of Rehabilitation Medicine, The Second Hospital of Dalian Medical University, 116023 Dalian, Liaoning, China.
PMID: 39613475 DOI: 10.31083/j.jin2311196
Abstract

Background: Avicularin (AL), an ingredient of Banxia, has anti-inflammatory properties in cerebral disease and regulates polarization of macrophages, but its effects on ischemic stroke (IS) damage have not been studied.

Methods: In vivo, AL was administered by oral gavage to middle cerebral artery occlusion/reperfusion (MCAO/R) C57BL/6J mice in doses of 1.25, 2.5, and 5 mg/kg/day for seven days, and, in vitro, AL was added to treat oxygen-glucose deprivation (OGD)-BV2 cells. Modified neurological severity score, Triphenyltetrazolium chloride (TTC) staining, brain-water-content detection, TdT-mediated dUTP nick-end labeling (TUNEL) assay, flow cytometry, immunofluorescence assay, Enzyme linked immunosorbent assay (ELISA), and Western-blot analysis were used to investigate the functions and mechanism of the effect of AL treatment on IS. The exosomes of AL-treated microglia were studied by transmission electron microscope (TEM), nanoparticle tracking analyzer (NTA), and Western-blot analysis.

Results: AL treatment reduced the neurological severity score, infarct volume, brain-water content, neuronal Apoptosis, and the release of inflammatory factors, that were induced by MCAO/R. Notably, M2 microglia polarization was promoted but M1 microglia polarization was inhibited by AL in the ischemic penumbra of MCAO/R mice. Subsequently, anti-inflammatory and polarization-regulating effects of AL were verified in vitro. Suppressed NOD-like Receptor thermal protein domain associated protein 3 (NLRP3) inflammasome activation was found in the ischemic penumbra of animal and Oxygen-Glucose Deprivation/Reoxygenation (OGD/R) cells treated with AL, as evidenced by decreasing NLRP3-inflammasome-related protein and downstream factors. After AL treatment, the anti-apoptosis effect of microglial exosomes on OGD/R primary cortical neurons was increased.

Conclusion: AL reduce inflammatory responses and neuron death of IS-associated models by regulating microglia polarization by the NLRP3 pathway and by affecting microglial exosomes.

Keywords
NLRP3; avicularin; ischemic stroke; microglia polarization; microglial exosomes.
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