Asian Spine J.  2014 Oct;8(5):557-564. 10.4184/asj.2014.8.5.557.

Evaluation of Behavior and Expression of Receptor Activator of Nuclear Factor-Kappa B Ligand in Dorsal Root Ganglia after Sciatic Nerve Compression and Application of Nucleus Pulposus in Rats

• Matsuyama
• Sakuma Y
• Suzuki M
• Orita S
• Yamauchi K
• Inoue G
• Aoki Y
• Ishikawa T
• Miyagi M
• Kamoda H
• Kubota G
• Oikawa Y
• Inage K
• Sainoh T
• Sato J
• Nakamura J
• Toyone T
• Takahashi
• Ohtori S

• KMID: 2270236
• DOI: http://doi.org/10.4184/asj.2014.8.5.557

Abstract

STUDY DESIGN: Experimental animal study. PURPOSE: To evaluate pain-related behavior and changes in nuclear factor-kappa B (NF-kB), receptor activator of NF-kB (RANK), and ligand (RANKL) in dorsal root ganglia (DRG) after combined sciatic nerve compression and nucleus pulposus (NP) application in rats. OVERVIEW OF LITERATURE: The pathological mechanisms underlying pain from lumbar-disc herniation have not been fully elucidated. RANKL are transcriptional regulators of inflammatory cytokines. Our aim was to evaluate pain-related behavior and RANKL expression in DRG after sciatic-nerve compression and application of NP in rats.
METHODS
Mechanical hyperalgesia and RANKL expression were assessed in three groups of rats: NP+sciatic nerve compression (2 seconds), sham-operated, and controls (n=20 each). Mechanical hyperalgesia was measured every other day for 3 weeks using von Frey filaments. RANKL expression in L5 DRGs was examined at five and ten days after surgery using immunohistochemistry.
RESULTS
Mechanical hyperalgesia was observed over the 12-day observation period in the NP+nerve compression group, but not in the control and sham-operated animal groups (p<0.05). RANKL immunoreactivity was seen in the nuclei of L5 DRG neurons, and its expression was significantly upregulated in NP+nerve compression rats compared with control and sham-operated rats (p<0.01).
CONCLUSIONS
The exposure of sciatic nerves to mechanical compression and NP produces pain-related behavior and up-regulation of RANKL in DRG neurons. RANKL may play an important role in mediating pain after sciatic nerve injury with exposure to NP.

Keyword

Rat; Pain; Nerve; Receptor activator of nuclear factor-kappa B ligand; Nucleus pulposus

MeSH Terms

Animals
Cytokines
Diagnosis-Related Groups
Ganglia, Spinal*
Hyperalgesia
Immunohistochemistry
Negotiating
Neurons
NF-kappa B
RANK Ligand*
Rats*
Sciatic Nerve*
Up-Regulation
Cytokines
NF-kappa B
RANK Ligand