Meningeal regulatory T cells inhibit nociception in female mice

Fibroblast reprogramming in the dura mater of NTG-induced migraine-related chronic hypersensitivity model drives monocyte infiltration via Angptl1-dependent stromal signaling

BACKGROUND

Migraine, characterized by recurrent episodes of severe headache, remains mechanistically enigmatic. While traditional theories emphasize trigeminovascular activation, the role of meningeal stromal-immune crosstalk in disease chronicity is poorly understood.

METHODS

A migraine-related chronic hypersensitivity model was utilized via intermittent intraperitoneal nitroglycerin (NTG, 10 mg/kg, every other day for 9 days) and peripheral mechanical hypersensitivity was assessed using von Frey filaments. Single-cell RNA sequencing (scRNA-seq) was performed on dura tissues to construct a cellular atlas of NTG-induced remodeling. These data were then integrated with migraine genome-wide association study (GWAS) risk genes, cell-cell interaction networks, and transcriptional regulation analysis to dissect NTG-driven meningeal remodeling.

RESULTS

The NTG-induced migraine-related chronic hypersensitivity model demonstrated sustained mechanical allodynia, as evidenced by significantly decreased paw withdrawal thresholds (p < 0.0001). Single-cell profiling of the dura mater revealed a 2.4-fold expansion of a pro-inflammatory fibroblast subpopulation (Fibro_c5: 1.9% in Vehicle vs. 4.6% in NTG group), which exhibited marked activation of TNF-α/NF-κB signaling pathways (normalized enrichment score [NES] = 1.83). Concomitantly, we observed an 82% increase in meningeal monocytes (5.7-10.4%) that showed preferential interaction with Fibro_c5 fibroblasts through Angptl1-mediated stromal-immune crosstalk (log2 fold change = 1.41). Regulatory network analysis identified Mafk as the upstream transcriptional regulator orchestrating Angptl1 expression in this pathological communication axis.

CONCLUSION

Our study reveals that NTG reprograms meningeal fibroblasts to expand a pro-inflammatory fibroblast subtype, which drives migraine-related chronic hypersensitivity through TNF-α/NF-κB signaling and Angptl1-mediated monocyte crosstalk. The identified Mafk-Angptl1 axis presents a potential therapeutic target, though human validation remains essential.

A recent history of immune cell sex differences in the peripheral nervous system in persistent pain states

Pain is entwined with inflammation, and biological sex often influences mechanisms of the immune system. Due to possible differences in inflammatory mechanisms, women are predisposed to autoimmune diseases and chronic pain. Despite sex as a critical variable in clinical cases of autoimmune conditions and its pain comorbidities, fundamental investigations have long underrepresented female subjects in their studies. Fundamental research in the 2010s, however, identified a binary sex specific mechanism for pain in rodents: male pain is microglia-driven while female pain is T cell-driven. Since then, studies have expanded in neuro-immunology to indicate that the sex differences and immune cells involved in these processes take on more elaborate roles when expanded to other causal modalities and anatomical levels of neuropathic and inflammatory pain. In this mini-review, we highlight updated roles for macrophages, T cells, and B cells in the peripheral nervous system during persistent pain conditions: neuropathic pain and inflammatory pain. We discuss sex similarities and sex differences in these cell types. By parsing out the sex specific roles of immune cells in persistent pain states, we may be better positioned to find immune-based therapies that can effectively target chronic pain in sex-biased autoimmune conditions.