Neuroinflammation in Spinal Cord Injury: Cellular and Molecular Mechanisms.

Area of Science:

• Neuroscience
• Immunology
• Regenerative Medicine

Background:

• Traumatic spinal cord injury (SCI) initiates intricate innate and adaptive immune responses.
• These immune responses evolve across acute and chronic phases, significantly impacting tissue regeneration and functional recovery.

Purpose of the Study:

• To review the phase-specific pathobiology of neuroinflammation following SCI.
• To elucidate the roles of various immune cells (microglia, macrophages, astrocytes, neutrophils, dendritic cells, T and B lymphocytes) in SCI.
• To summarize recent advancements in understanding glial heterogeneity and key signaling pathways.

Main Methods:

• Synthesis of existing literature on SCI immunology.
• Analysis of data from single-cell RNA sequencing and spatial transcriptomics.
• Review of glial heterogeneity beyond binary models.
• Examination of signaling pathways like NF-κB and NLRP3 inflammasome.

Main Results:

• Immune responses in SCI are complex and phase-dependent, involving diverse cell types.
• Single-cell technologies reveal state- and region-specific immune programs and pathogenic/reparative circuits.
• Key immune mediators like TNF-α, IL-1β, and IL-6 exhibit dual actions.

Conclusions:

• Precision immunomodulation tailored to injury stage, cell state, and region is crucial for SCI recovery.
• Strategies include managing microglial activation, redirecting astrocyte states, and modulating immune cell crosstalk.
• Future research should focus on validating immune nodes and developing stage-specific immunotherapies.