Scientific Paper: integrated Analysis of Single-cell and Transcriptome Data Reveals Temporal Dynamics of Microglial Phagocytic Reprogramming in Neuropathic Pain Progression

Objectives
To investigate the temporal dynamics of microglial phagocytic reprogramming during the progression of neuropathic pain.
Design
Using the spared nerve injury mouse model combined with single-cell transcriptomics, pseudotime trajectory analysis, in vivo and in vitro experiments.
Results
Axl drives the biphasic phagocytic evolution of spinal microglia post-injury, linking initial enhancement to subsequent decline and neuropathic pain resolution.

Conclusions
Axl drives microglial phagocytic evolution across three phases after nerve injury, revealing its key role in chronic neuropathic pain and therapeutic potential.

Through integrated multi-omics analysis and experimental validation, this study investigates microglial phagocytic reprogramming in neuropathic pain. In the spared nerve injury model, spinal microglia evolve through three phases: acute proliferation (PID3), transitional phagocytic activation (PID7), and chronic autophagy-sustained phagocytosis (PID14). Single-cell transcriptomics revealed functional heterogeneity with pro-inflammatory and phagocytic subsets. Pseudotime analysis showed differentiation from a common progenitor into distinct lineages. Chronic phase analysis confirmed microglial activation with enhanced apoptotic cell clearance. Among eight phagocytosis-related genes identified, Axl showed maximal chronic-phase upregulation. Axl inhibition induced mechanical allodynia and impaired phagocytosis. LPS stimulation triggers a biphasic phagocytic response—initial enhancement followed by decline—a process regulated by Axl. This work establishes Axl as a key regulator and therapeutic target for chronic neuropathic pain.