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Published on: March 17, 2015
β-Lactam TRPM8 Antagonist RGM8-51 Displays Antinociceptive Activity in Different Animal Models
Cristina Martín-Escura1,2, Alicia Medina-Peris3, Luke A Spear1
1Instituto de Química Médica (IQM-CSIC), 28006 Madrid, Spain.
Abstract:
Transient receptor potential melastatin subtype 8 (TRPM8) is a cation channel extensively expressed in sensory neurons and implicated in different painful states. However, the effectiveness of TRPM8 modulators for pain relief is still a matter of discussion, since structurally diverse modulators lead to different results, depending on the animal pain model. In this work, we described the antinociceptive activity of a β-lactam derivative, RGM8-51, showing good TRPM8 antagonist activity, and selectivity against related thermoTRP channels and other pain-mediating receptors. In primary cultures of rat dorsal root ganglion (DRG) neurons, RGM8-51 potently reduced menthol-evoked neuronal firing without affecting the major ion conductances responsible for action potential generation. This compound has in vivo antinociceptive activity in response to cold, in a mouse model of oxaliplatin-induced peripheral neuropathy. In addition, it reduces cold, mechanical and heat hypersensitivity in a rat model of neuropathic pain arising after chronic constriction of the sciatic nerve. Furthermore, RGM8-51 exhibits mechanical hypersensitivity-relieving activity, in a mouse model of NTG-induced hyperesthesia. Taken together, these preclinical results substantiate that this TRPM8 antagonist is a promising pharmacological tool to study TRPM8-related diseases.
Insights
A novel beta-lactam derivative, RGM8-51, acts as a Transient Receptor Potential Melastatin Subtype 8 (TRPM8) antagonist. This compound demonstrates significant pain relief in preclinical models of neuropathy and hyperesthesia.
Area of Science:
- Neuroscience
- Pharmacology
- Pain Research
Background:
- Transient Receptor Potential Melastatin Subtype 8 (TRPM8) channels are key players in sensory neurons and pain pathways.
- The therapeutic potential of TRPM8 modulators for pain management remains debated due to varied outcomes across different pain models.
Purpose of the Study:
- To evaluate the antinociceptive properties of a novel beta-lactam derivative, RGM8-51, as a TRPM8 antagonist.
- To assess the selectivity of RGM8-51 against related thermoTRP channels and other pain receptors.
Main Methods:
- In vitro assessment of RGM8-51's effect on menthol-evoked neuronal firing in rat dorsal root ganglion (DRG) neurons.
- In vivo evaluation of RGM8-51's antinociceptive activity in mouse models of oxaliplatin-induced peripheral neuropathy and NTG-induced hyperesthesia.
- Assessment of RGM8-51's efficacy in a rat model of neuropathic pain induced by chronic sciatic nerve constriction.
Main Results:
- RGM8-51 effectively inhibited menthol-evoked neuronal activity in DRG neurons without impacting essential ion conductances.
- The compound demonstrated in vivo antinociceptive effects against cold stimuli in a chemotherapy-induced neuropathy model.
- RGM8-51 alleviated cold, mechanical, and heat hypersensitivity in neuropathic pain models and mechanical hypersensitivity in a hyperesthesia model.
Conclusions:
- RGM8-51 exhibits potent TRPM8 antagonist activity and selectivity.
- Preclinical data support RGM8-51 as a promising pharmacological agent for investigating TRPM8-associated pain conditions.
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