Search bioRxiv⌕ Search

Biology subjects

Salvemini, D.

Publications and source records attributed to Salvemini, D..

2 recordsLinked to original sources

Targeting GPR183 to reduce peripheral sensitization: evidence from rodent and human tissue analyses

Peripheral sensitization is a key process in the development of painful inflammatory conditions, driven in part by immune-cell mediator release following tissue injury. The G protein-coupled receptor, GPR183, predominantly expressed on immune cells, regulates their migration, positioning, and mediator production. Yet its role in peripheral sensitization and the specific immune cells involved remains insufficiently understood. In rats, intraplantar injection of 7,25-dihydroxycholesterol (7,25-OHC), the most potent endogenous GPR183 ligand, produced long-lasting nociception that was prevented by the selective GPR183 antagonist SAE-14. Because GPR183 activates ERK signaling, which influences pain pathways including nitric oxide synthase (NOS) activity and NO formation, we used NOS inhibitors and knockout animals to test the contribution of inducible and neuronal NOS isoforms to 7,25-OHC-induced sensitization. We found that both isoforms influence this response, independent of cyclooxygenases. In a well-characterized rat incisional injury model, GPR183 protein expression increased in injured paw tissue, and SAE-14 reversed hypersensitivity. Meta-analysis of human post-surgical skin samples similarly showed elevated GPR183 expression and transcriptional changes favoring 7,25-OHC production after injury. We identified macrophages and Langerhans cells (LCs) as the principal GPR183-expressing cell types in human skin. LC ablation studies revealed that 7,25-OHC-evoked hypersensitivity does not depend on LCs, implicating GPR183+ macrophages as predominant drivers of GPR3-induced hypersensitivity. Overall, our findings define the cellular and molecular pathways linking GPR183 to peripheral sensitization and highlight GPR183 antagonism as a promising strategy for pain management.

pharmacology and toxicology↗

Contribution of S1pr1-featured astrocyte subpopulation to cisplatin-induced neuropathic pain

Chemotherapy-induced peripheral neuropathy accompanied by neuropathic pain (CIPN) is a major neurotoxicity of cisplatin, a platinum-based drug widely used for lung, ovarian, and testicular cancer treatment. CIPN causes drug discontinuation and severely impacts life quality with no FDA-approved interventions. We previously reported that platinum-based drugs increase levels of sphingosine 1-phosphate (S1P) in the spinal cord and drive CIPN through activating the S1P receptor subtype 1 (S1PR1). However, the mechanisms engaged downstream of S1PR1 remain poorly understood. Using single cell transcriptomics on male mouse spinal cord, our findings uncovered subpopulation-specific responses to cisplatin associated with CIPN. Particularly, cisplatin increased the proportion of astrocytes with high expression levels of S1pr1 (S1pr1high astrocytes), specific to which a Wnt signaling pathway was identified. To this end, several genes involved in Wnt signaling, such as the fibroblast growth factor receptor 3 gene (Fgfr3), were highly expressed in S1pr1high astrocytes. The functional S1PR1 antagonist, ozanimod, prevented cisplatin-induced neuropathic pain and astrocytic upregulation of the Wnt signaling pathway genes. FGFR3 belongs to the FGF/FGFR family which often signals to activate Wnt signaling. Intrathecal injection of the FGFR3 antagonist, PD173074, prevented the development of CIPN in male mice. These data not only highlight FGFR3 as one of the astrocytic targets of S1PR1 but raise the possibility that S1PR1-induced engagement of Wnt signaling in S1pr1high astrocytes may contribute to CIPN. Overall, our results provide a comprehensive mapping of cellular and molecular changes engaged in cisplatin-induced neuropathic pain and decipher novel S1PR1-based mechanisms of action.

neuroscience↗