Spinal SIRPα1-SHP2 interaction regulates spinal nerve ligation-induced neuropathic pain via PSD-95-dependent NR2B activation in rats.

Abstract

The fact that neuropathic pain mechanisms are not well understood is a major impediment in the development of effective clinical treatments. We examined whether the interaction between signal regulatory protein alpha 1 (SIRPα1) and Src homology-2 domain-containing protein tyrosine phosphatase 2 (SHP2), and the downstream spinal SHP2/postsynaptic density 95 (PSD-95)/N-methyl-d-aspartate receptor NR2B subunit signaling cascade play a role in neuropathic pain. Following spinal nerve ligation (L5), we assessed tactile allodynia using the von Frey filament test and analyzed dorsal horn samples (L4-5) by Western blotting, reverse transcription polymerase chain reaction, coimmunoprecipitation, and immunofluorescence. Nerve ligation induced allodynia, SIRPα1, SHP2, phosphorylated SHP2 (pSHP2), and phosphorylated NR2B (pNR2B) expression, and SHP2-PSD-95, pSHP2-PSD-95, PSD-95-NR2B, and PSD-95-pNR2B coimmunoprecipitation in the ipsilateral dorsal horn. In allodynic rats, injury-induced SHP2 immunoreactivity was localized in the ipsilateral dorsal horn neurons and coincident with PSD-95 and NR2B immunoreactivity. SIRPα1 silencing using small interfering RNA (siRNA; 1, 3, or 5μg/rat for 7days) prevented injury-induced allodynia and the associated changes in protein expression, phosphorylation, and coimmunoprecipitation. Intrathecal administration of NSC-87877 (an SHP2 antagonist; 1, 10, or 100μM/rat) and SIRPα1-neutralizing antibodies (1, 10, or 30μg/rat) suppressed spinal nerve ligation-induced allodynia, spinal SHP2 and NR2B phosphorylation, and SHP2/phosphorylated SHP2-PSD-95 and PSD-95-NR2B/phosphorylated NR2B coprecipitation. SHP2 siRNA led to similar effects as the NSC-87877 and SIRPα1 antibody treatments, except it prevented the allodynia-associated spinal SHP2 expression. In conclusion, our results suggest that a spinal SIRPα1-SHP2 interaction exists that subsequently triggers SHP2/PSD-95/NR2B signaling, thereby playing a role in neuropathic pain development.

• Authors: Hsien-Yu Peng, Gin-Den Chen, Cheng-Yuang Lai, Ming-Chun Hsieh, Tzer-Bin Lin
• Journal: Pain (Pain) Vol. 153 Issue 5 Pg. 1042-1053 (May 2012) ISSN: 1872-6623 [Electronic] United States
• PMID: 22425446 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2012 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Chemical References

• Disks Large Homolog 4 Protein
• Dlg4 protein, rat
• Intracellular Signaling Peptides and Proteins
• Membrane Proteins
• NR2A NMDA receptor
• NR2B NMDA receptor
• Receptors, Immunologic
• Receptors, N-Methyl-D-Aspartate
• Sirpa protein, rat
• Protein Tyrosine Phosphatase, Non-Receptor Type 11

Topics

• Animals
• Disks Large Homolog 4 Protein
• Hyperalgesia (metabolism)
• Intracellular Signaling Peptides and Proteins (metabolism)
• Male
• Membrane Proteins (metabolism)
• Neuralgia (metabolism)
• Pain Measurement
• Phosphorylation
• Protein Tyrosine Phosphatase, Non-Receptor Type 11 (metabolism)
• Rats
• Rats, Sprague-Dawley
• Receptors, Immunologic (metabolism)
• Receptors, N-Methyl-D-Aspartate (metabolism)
• Spinal Nerves (injuries, metabolism)