Macrophages and microglia in inflammation and neuroinflammation underlying different pain states

Area of Science:

• Neuroscience
• Immunology
• Pain Research

Background:

• Pain is a primary symptom of inflammation, driven by inflammatory mediators acting on nociceptive neurons.
• Macrophages (immune cells) and microglia (central nervous system glial cells) are crucial regulators of pain, despite their distinct origins.
• Macrophage polarization significantly influences the induction and resolution of pain.

Purpose of the Study:

• To review macrophage and microglial signaling pathways involved in pain.
• To explore the role of specialized pro-resolution mediators (SPMs) in pain resolution.
• To highlight sex differences in immune cell signaling in pain.

Main Methods:

• Review of existing literature on macrophage and microglial roles in pain.
• Analysis of signaling mechanisms in pain induction and resolution.
• Examination of immunomodulatory and neuromodulatory effects of SPMs.

Main Results:

• Macrophage polarization is critical for both initiating and resolving pain.
• SPMs can inhibit inflammatory and neuropathic pain through immunomodulation and neuromodulation.
• Microglia contribute to neuroinflammation and pathological pain by releasing inflammatory cytokines.
• Sex differences exist in macrophage and microglial signaling in pain.

Conclusions:

• Targeting macrophage and microglial signaling offers a promising strategy for managing chronic inflammation and pain.
• Pharmacological and non-pharmacological approaches targeting these cells can control chronic pain.
• Understanding the distinct roles of macrophages and microglia is key to developing effective pain therapies.