Methylene Blue Mitigates Acute Neuroinflammation after Spinal Cord Injury through Inhibiting NLRP3 Inflammasome...

Area of Science:

• Neuroscience
• Immunology
• Pharmacology

Background:

• Spinal cord injury (SCI) causes significant neurological damage due to primary injury and secondary neuroinflammation.
• Microglia play a critical role in the inflammatory response following SCI.
• Targeting neuroinflammation is a key strategy for improving functional recovery after SCI.

Purpose of the Study:

• To investigate the therapeutic potential of methylene blue in mitigating neuroinflammation post-SCI.
• To examine the effects of methylene blue on microglia activation and inflammasome pathways in vitro and in vivo.

Main Methods:

• In vitro studies on activated microglia to assess methylene blue's impact on cytokine production and inflammasome activation.
• In vivo studies using a rat SCI model to evaluate methylene blue's effects on microglia, neuroinflammation, neuronal apoptosis, and locomotor function.
• Measurement of cytokine protein and mRNA levels, inflammasome activation markers, reactive oxygen species (ROS), leukocyte infiltration, and functional recovery.

Main Results:

• Methylene blue inhibited protein levels of IL-1β and IL-18 in activated microglia, decreasing NLRP3 and NLRC4 inflammasome activation.
• In the SCI rat model, methylene blue reduced neuroinflammation, including pro-inflammatory cytokine production and leukocyte infiltration.
• Methylene blue treatment led to partial inhibition of neuronal apoptosis and amelioration of hind limb locomotor function.

Conclusions:

• Methylene blue effectively inhibits microglia-mediated neuroinflammation following spinal cord injury.
• The mechanism involves the down-regulation of inflammasome pathways and reactive oxygen species.
• Methylene blue shows promise as a therapeutic agent for spinal cord injury.