do Nascimento, A. M. | bioRxiv Science

bioRxiv2026

Subtype-Resolved Pain-Signaling Architectures Reveal Conserved Drug-Target Interaction Networks in DRG Nociceptors

Pain management has been challenging and a major obstacle lies in the limited translational success between preclinical studies, often based on rodent models and evoked nociception behavioral assays, whose validity is often questioned. The dorsal root ganglia (DRG) contains diverse nociceptor subtypes that serve as the primary afferent pathways for detecting painful stimuli and analgesics often target proteins expressed in nociceptors. This makes the distinct protein repertoires and molecular interactors within nociceptor subtypes a key focus for understanding which molecular players drive pain processing and how they may be therapeutically targeted. The confirmation of cross-species conservation of pain-related signaling pathways, mediated by nociceptors, could help to elucidate the molecular mechanisms by which the drugs act across species. In this context, we constructed and compared experimentally-validated protein-protein interaction (PPI) networks based on drug targets and their direct binding partners for nociceptor subtypes supported by single-nuclei transcriptome data from mouse and human DRGs. We found that overall gene expression is more conserved across mice than in human nociceptor subtypes, indicating a higher degree of molecular specialization of human nociceptors. Overall signaling network analyses revealed subtype- and species-specific conservation related to pain signaling, with some particularities, in which key drug targets mediate broader cellular processes beyond pain signaling and neuronal depolarization. Altogether, this resource may help to further understand the molecular mechanisms of specific drug targeting, and the proposed workflow can be used to identify and prioritize pain-related pathways in the DRG, advancing target identification and translational medicine.

cell biology↗

bioRxiv2026

Temporal regulation of TRP channels during partial sciatic nerve ligation is modulated by PLCγ in male mice

Neuropathic pain is a debilitating condition afflicting millions worldwide, still lacking a proper and effective treatment. Understanding the underlying mechanisms that lead to neuropathic pain may lead to the discovery of new targets. Previously, we found that PLC{square} is a key player in mechanical hypersensitivity triggered by either capsaicin or complete Freunds adjuvant induced inflammation. Here, we investigated the role of PLC{gamma} in neuropathic pain using a partial sciatic nerve ligation (PSNL) injury model in male mice and a peptide inhibitor of PLC{gamma} activation (TAT-pQYP) injected at different time points after injury. Mechanical hypersensitivity was reversed by TAT-pQYP at 7, 14, and 28 days post-injury (dpi). Furthermore, both TAT-pQYP and the TRPA1 inhibitor HC-030031, but not the TRPV1 inhibitor capsazepine, were able to reverse mechanical hypersensitivity at 14 dpi. In contrast, all three treatments significantly improved the mechanical threshold at 28 dpi. After a challenge with TRPV1 agonist capsaicin at 14 dpi, TAT-pQYP treated animals exhibited increased sensitivity. We also found decreased TRPV1 mRNA levels in the DRG of PSNL animals at 14 dpi that returned to baseline at 28 dpi. TAT-pQYP treatment normalized TRPV1 expression to sham levels at 14 days. Conversely, TRPA1 mRNA expression increased at 14 days and returned to baseline at 28 days, while TAT-pQYP reduced TRPA1 expression at 14 days. At this same time point, injection of a pan-PLC (U73122), or Trk (GNF-5837) inhibitor reduced mechanical hypersensitivity and decreased Trpa1 expression, whereas only PLC{square} inhibition by TAT-pQYP or Trk inhibition restored Trpv1 levels to Sham values. These findings indicate that PLC{gamma}, and Trk signaling are important for expression of Trpa1 and activity of Trpv1. Taken together, our results show that dynamic changes in Trpv1 expression in the PSNL model account for differential sensitivity to TRPV1 inhibition and suggest that clinically relevant pharmacological inhibitors targeting ion channels may vary in efficacy depending on the temporal regulation of expression during neuropathic pain development. Finally, we show that TAT-pQYP is able to reverse mechanical hypersensitivity arising from neuropathic pain, adding evidence that PLC{gamma} is a promising target to be explored for neuropathic pain management. Significance statementWe show that the efficacy of inhibiting TRPV1 or TRPA1 on neuropathic pain in a partial sciatic nerve ligation model and that pain mitigation depends on the dynamic changes of channel expression post-injury, in the dorsal root ganglion, emphasizing that temporal regulation of drug targets should be taken into account when choosing therapeutic strategies for pain treatment. Notably, we identify PLC{gamma} as a promising therapeutic target, as its inhibition with TAT-pQYP reverses mechanical hypersensitivity during different stages of injury progression by modulating expression and activity of TRP channels.

biochemistry↗