FOXA2 regulated by HDAC3-mediated deacetylation attenuates neuropathic pain by modulating microglial lipid metabolism and synaptic pruning dysregulation.

BACKGROUND: Persistent neuroinflammation and synaptic dysregulation in the spinal dorsal horn (SDH) has been well-established as a critical mechanism contributing to neuropathic pain (NP). Microglia play a pivotal role in modulating both neuroinflammatory responses and synaptic pruning. While metabolic disturbances are known to significantly impact microglial functionality, the precise mechanistic relationship remains poorly understood. METHODS: This study seeks to elucidate how FOXA2-mediated regulation of lipid metabolism influences microglial function. Multiple assays were conducted on mouse SDH tissues and in vitro microglial cells, including immunofluorescence, transmission electron microscopy (TEM), qRT-PCR, Western blot (WB), and specific indicator assay kits, to comprehensively evaluate: (i) microglial lipid metabolism, (ii) mitochondrial morphology and functional integrity, (iii) inflammatory cytokine levels, and (iv) synaptic phagocytic activity. AAV-mediated FOXA2 overexpression or knockdown was employed to investigate its therapeutic effects on NP via modulating microglial lipid metabolism homeostasis. Transcriptome sequencing analysis, Co-immunoprecipitation (Co-IP), chromatin immunoprecipitation (ChIP), and dual-luciferase reporter assays were employed to investigate the regulatory mechanisms among HDAC3, CPT1A, and FOXA2. RESULTS: Here we demonstrate that both spared nerve injury (SNI) and lipopolysaccharide (LPS) stimulation trigger significant lipid droplet accumulation and mitochondrial dysfunction in microglia, leading to impaired phagocytic function. FOXA2 ameliorates NP by upregulating CPT1A to restore microglial lipid metabolism and mitochondrial homeostasis, thereby meliorating dysregulated synaptic pruning and alleviating neuroinflammation. We identified HDAC3-mediated deacetylation as a critical regulatory mechanism controlling FOXA2 transcriptional activity. Pharmacological inhibition of HDAC3 by RGFP966 significantly enhanced FOXA2 binding to the CPT1A promoter region, thereby amplifying FOXA2-dependent lipid metabolic reprogramming in microglia. CONCLUSIONS: Collectively, our study establishes microglial lipid metabolism as a critical regulator of NP pathogenesis, orchestrating both neuroinflammatory responses and synaptic remodeling processes. These findings unveil novel therapeutic opportunities for pain management through targeted modulation of microglial metabolic homeostasis.