Expression of granulocyte colony-stimulating factor 3 receptor in the spinal dorsal horn following spinal nerve ligation-induced neuropathic pain

In previous studies that have profiled gene expression in patients with complex regional pain syndrome (CRPS), the expression of granulocyte colony-stimulating factor 3 receptor (G-CSFR) was elevated, as were a number of pain-associated genes. The present study determined the expression of G-CSFR and the mechanisms by which it may affect hypersensitivity, focusing on the signal transducer and activator of transcription 3 (STAT3)/transient receptor potential cation channel subfamily V 1 (TRPV1) signaling pathway in particular, which is an important mediator of pain. Following L5 spinal nerve ligation (SNL) surgery, the protein and mRNA levels of G-CSFR increased in the ipsilateral spinal dorsal horn when compared with the sham and/or contralateral control. Double immunofluorescence further demonstrated that G-CSFR colocalized with TRPV1 and phosphorylated STAT in the neurons of the spinal dorsal horn. G-CSF treatment led to an increase in G-CSFR and TRPV1 expression and phosphorylation of STAT3. These results indicate that G-CSF-induced G-CSFR expression may activate TRPV1 by promoting phosphorylation of STAT3. Collectively, the results suggest, for the first time, that the expression of G-CSFR in neurons following peripheral nerve injury may be involved in the induction and maintenance of neuropathic pain through the STAT3 and TRPV1 signaling pathway.