Netrin-1 Promotes M2 Type Activation and Inhibits Pyroptosis of Microglial Cells by Depressing RAC1/Nf-?B Pathway to...

Area of Science:

• Neuroscience
• Immunology
• Molecular Biology

Background:

• Netrin-1 (NTN-1) is crucial for nervous system development and inflammatory diseases.
• The specific role and mechanism of NTN-1 in inflammatory pain (IP) remain largely unelucidated.
• Microglia play a key role in neuroinflammation and pain signaling.

Purpose of the Study:

• To investigate the role and underlying mechanism of Netrin-1 (NTN-1) in inflammatory pain (IP).
• To determine if NTN-1 can modulate microglial activation and pyroptosis in the context of IP.

Main Methods:

• BV2 microglia treated with lipopolysaccharide (LPS) to model IP.
• Overexpression of NTN-1 using adeno-associated virus (AAV-NTN-1).
• Complete Freund's Adjuvant (CFA)-induced mouse model for in vivo studies.
• Assays included MTT, ELISA, and Western blotting to assess cell viability, cytokine levels, pyroptosis, and signaling pathways (Rac1/NF-kappaB).

Main Results:

• NTN-1 expression was decreased in LPS-stimulated microglia and CFA-induced mouse spinal cords.
• NTN-1 overexpression reduced BV2 cell death and pyroptosis induced by LPS.
• AAV-NTN-1 treatment suppressed microglial activation, decreased pro-inflammatory cytokines (iNOS, IL-1beta, IL-6), and promoted anti-inflammatory markers (Arg-1, IL-4, IL-10).
• NTN-1 inhibited the Rac1/NF-kappaB signaling pathway activation.

Conclusions:

• Netrin-1 (NTN-1) alleviates inflammatory pain (IP) by suppressing microglial pyroptosis and promoting M2 polarization.
• The mechanism involves the inhibition of the Rac1/NF-kappaB signaling pathway.
• NTN-1 demonstrates a protective role in inflammatory pain, suggesting therapeutic potential.