Neutrophil Nanovesicle Protects against Experimental Autoimmune Encephalomyelitis through Enhancing Myelin Clearance...

Area of Science:

• Neuroscience
• Immunology
• Biotechnology

Background:

• Effective clearance of myelin debris is crucial for resolving neuroinflammation and enabling tissue regeneration in multiple sclerosis (MS).
• Microglia, the primary phagocytes in MS lesions, exhibit impaired myelin debris clearance in patients.
• Developing strategies to enhance microglial phagocytosis is essential for MS therapy.

Purpose of the Study:

• To investigate the therapeutic potential of neutrophil-derived nanovesicles (NNVs) for enhancing myelin debris clearance in microglia.
• To evaluate the efficacy of NNVs in ameliorating neuroinflammation and improving neurological function in a mouse model of MS.

Main Methods:

• RNA sequencing (RNAseq) to analyze gene expression changes in response to NNVs treatment in experimental autoimmune encephalomyelitis (EAE) mice.
• Assay for Transposase Accessible Chromatin using sequencing (ATACseq) to identify changes in microglial transcription factor activity.
• Assessment of neurological function and white matter integrity in EAE mice following NNVs administration.

Main Results:

• NNVs treatment significantly ameliorated lesional neuroinflammation in EAE mice.
• EAE mice treated with NNVs showed improved neurological functions and preserved white matter integrity.
• NNVs upregulated nuclear factor E2-related factor 2 (NRF2) expression in microglia, activating RUBCN transcription and enhancing LC3-associated phagocytosis (LAP).
• Efficient catabolism of myelin debris was observed in NNVs-treated mice without significant side effects.

Conclusions:

• NNVs represent a promising therapeutic strategy for MS by enhancing microglial-mediated myelin debris clearance.
• The NNVs-NRF2-RUBCN-LAP pathway is a key mechanism by which NNVs modulate neuroinflammation and promote recovery.