Substance P Mediates Estrogen Modulation Proinflammatory Cytokines Release in Intervertebral Disc

Area of Science:

• Biomedical Science
• Inflammation Research
• Pain Management

Background:

• Intervertebral disc degeneration (IDD) is a primary cause of low back pain.
• Estrogen and Substance P (SP) are implicated in inflammation and pain pathways relevant to IDD.

Purpose of the Study:

• To investigate the role of SP in estrogen's regulation of IDD.
• To explore estrogen's mechanisms in modulating inflammation and pain in IDD.

Main Methods:

• Ovariectomy (OVX) and estrogen replacement therapy (ERT) in a mouse model.
• Analysis of SP, neurokinin 1 receptor (NK1R), IL-1β, IL-6, and TNF-α expression via immunohistochemistry and qPCR.
• Administration of NK1R agonist to assess its effect on estrogen-induced changes.

Main Results:

• OVX increased TNF-α, IL-1β, IL-6, SP, and NK1R expression in intervertebral disc cells.
• ERT reversed these increases, demonstrating anti-inflammatory and anti-hyperalgesic effects.
• NK1R agonists significantly inhibited estrogen-induced pro-inflammatory cytokine changes.

Conclusions:

• Estrogen influences IDD inflammation through direct cytokine modulation and SP pathway.
• SP acts as a key mediator in estrogen's regulation of pro-inflammatory factors in IDD.
• Estrogen therapy shows potential for managing IDD and associated low back pain.