title: 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.affiliation: Department of Medicine, Mackay Medical College, New Taipei, Taiwan Department of Urology, China Medical University Hospital, Taichung, Taiwan Department of Obstetrics and Gynecology, Chung-Shan Medical University Hospital, Chung-Shan Medical University, Taichung, Taiwan Department of Physiology, School of Medicine, College of Medicine, China Medical University, Taichung, Taiwan Department of Veterinary Medicine, College of Veterinary Medicine, National Chung-Hsing University, Taichung, Taiwan Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan.
authors.forename: Hsien-Yu
authors.initials: HY
authors.lastname: Peng
authors.forename: Gin-Den
authors.initials: GD
authors.lastname: Chen
authors.forename: Cheng-Yuang
authors.initials: CY
authors.lastname: Lai
authors.forename: Ming-Chun
authors.initials: MC
authors.lastname: Hsieh
authors.forename: Tzer-Bin
authors.initials: TB
authors.lastname: Lin
mesh_terms: D000818:Animals; D000076122:Disks Large Homolog 4 Protein; D006930:Hyperalgesia / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism*; D009437:Neuralgia / Q000378:metabolism*; D010147:Pain Measurement; D010766:Phosphorylation; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11 / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011971:Receptors, Immunologic / Q000378:metabolism*; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*; D013127:Spinal Nerves / Q000293:injuries* / Q000378:metabolism
chemical_list: D000076122:Disks Large Homolog 4 Protein; C501449:Dlg4 protein, rat; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; C120997:NR2A NMDA receptor; C121001:NR2B NMDA receptor; D011971:Receptors, Immunologic; D016194:Receptors, N-Methyl-D-Aspartate; C501924:Sirpa protein, rat; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11