An Integrated Multi-Tissue Single-Cell Transcriptomic Analysis Highlights the CCL2-CCR2 Signaling Pathway as a Potential Therapeutic Target in Neuropathic Pain

Abstract

Background Neuropathic pain involves complex neuroimmune interactions across the somatosensory nervous system, yet a comprehensive multi-tissue cellular landscape remains lacking. Methods We integrated single-cell RNA sequencing data from the sciatic nerve (SN), dorsal root ganglion (DRG), and spinal cord (SC) of spared nerve injury (SNI) mice. The therapeutic potential of the selective CCR2 antagonist RS504393 was evaluated in vivo. Results Macrophages dominated the injured SN (40.5%), exhibiting an inferred transcriptional shift from a resident-like Mrc1+ phenotype toward proinflammatory Ccl2+/Spp1+ subtypes. Injury elevated glycolytic activity in SN macrophages and spinal microglia, but suppressed metabolism in DRG neurons. Cell-cell communication analysis predicted enhanced CCL2-CCR2 signaling from peripheral macrophages to sensory neurons in the Pain group. In vivo, RS504393 administration significantly alleviated mechanical and thermal hypersensitivity, reduced spinal inflammatory infiltration, and suppressed microglial activation. Conclusion This study provides an integrated multi-tissue single-cell analysis of neuropathic pain and highlights the CCL2-CCR2 signaling pathway as a potential non-opioid therapeutic target at the peripheral neuroimmune interface, with pharmacological evidence suggesting downstream central effects.