Electroacupuncture alleviates central post-stroke pain in rats by modulating miR-21-5p/TGF-β/Smads pathway

Area of Science:

• Neuroscience
• Pain Research
• Molecular Biology

Background:

• Central post-stroke pain (CPSP) is a challenging condition with limited treatment options.
• MicroRNA-21 (miR-21) and the TGF-β/Smads pathway are implicated in pain.
• The role of miR-21/TGF-β/Smads in electroacupuncture (EA) for CPSP is unclear.

Purpose of the Study:

• To investigate if EA's analgesic effect in CPSP is mediated by the miR-21/TGF-β/Smads pathway.
• To explore the molecular mechanisms of EA in CPSP.

Main Methods:

• CPSP was induced in rats via stereotactic collagenase-IV injection.
• miR-21-5p and Smad7 levels were manipulated using adenoviral vectors.
• Pain thresholds, neuronal damage, glial activation, and inflammatory markers were assessed.
• A dual-luciferase reporter assay confirmed direct interaction between miR-21-5p and Smad7.

Main Results:

• EA significantly reduced CPSP and neuroinflammation markers.
• EA downregulated miR-21-5p and upregulated Smad7, decreasing TGF-β1, p-Smad2, and p-Smad3.
• Inhibition of miR-21-5p mimicked EA's analgesic effect; its overexpression or Smad7 inhibition reversed EA's benefits.

Conclusions:

• EA analgesia in CPSP involves downregulating miR-21-5p.
• This action inhibits neuroinflammation via the Smad7/TGF-β/Smads pathway.
• Provides novel molecular insights into EA's mechanism for pain relief.