Novel selective, potent naphthyl TRPM8 antagonists identified through a combined ligand- and structure-based virtual screening approach

Abstract

Transient receptor potential melastatin 8 (TRPM8), a nonselective cation channel, is the predominant mammalian cold temperature thermosensor and it is activated by cold temperatures and cooling compounds, such as menthol and icilin. Because of its role in cold allodynia, cold hyperalgesia and painful syndromes TRPM8 antagonists are currently being pursued as potential therapeutic agents for the treatment of pain hypersensitivity. Recently TRPM8 has been found in subsets of bladder sensory nerve fibres, providing an opportunity to understand and treat chronic hypersensitivity. However, most of the known TRPM8 inhibitors lack selectivity, and only three selective compounds have reached clinical trials to date. Here, we applied two virtual screening strategies to find new, clinics suitable, TRPM8 inhibitors. This strategy enabled us to identify naphthyl derivatives as a novel class of potent and selective TRPM8 inhibitors. Further characterization of the pharmacologic properties of the most potent compound identified, compound 1, confirmed that it is a selective, competitive antagonist inhibitor of TRPM8. Compound 1 also proved itself active in a overreactive bladder model in vivo. Thus, the novel naphthyl derivative compound identified here could be optimized for clinical treatment of pain hypersensitivity in bladder disorders but also in different other pathologies.

Combining Molecular Dynamics and Docking Simulations to Develop Targeted Protocols for Performing Optimized Virtual Screening Campaigns on the hTRPM8 Channel

“…Docking simulations involved the same dataset already utilized in a previous study, which is composed of 5300 molecules, 53 of which are known binders and 5247 are experimentally proven as known-binders. Each ligand was prepared by considering the predominant form at physiological pH as described in [17]. Additionally, all collected molecules were minimized by semi-empirical methods using the PM6 Hamiltonian as implemented in MOPAC [39].…”

“…For many years, the only structure available for TRPM8 was a homology model developed by some of us and based on a fragmental strategy, which combined different templates [16]. While considering its significant inaccuracies, this model showed an encouraging predictive power even when applied for virtual screening campaigns as seen for the identification of a novel set of naphthyl ligands [17].…”

“…After a preliminary indirect re-docking study performed to select the most interesting frames as well as to calibrate the settings of the various docking programs, virtual screening campaigns involved the same database utilized in our previous study, which includes 53 known TRPM8 antagonists combined with 4947 true inactive molecules as derived from high-throughput screening. [17] For each selected TRPM8 structure, the four corresponding monomers underwent docking simulations and the computed complexes were rescored by ReScore+ [23] and then utilized to develop consensus equations based on the recently proposed EFO method [24]. As detailed in the results, highly effective consensus equations were generated when combining the docking results as computed for the four monomers of the same TRPM8 tetramer.…”

TRP Channels as Lower Urinary Tract Sensory Targets

“…Several new antagonists have been described [124,125], and some of them have been tested in animals for their effects on normal LUT and in models of LUT disorders [80,82,126,127,128,129,130].…”

Highly functionalized β-lactams and 2-ketopiperazines as TRPM8 antagonists with antiallodynic activity

“…Also different acyclic central scaffolds (amide, sulfonamide, urea, glycine, tryptophan), decorated with aromatic and heterocyclic rings are reported as TRPM8 antagonists (Fig. 1 ) 33 – 35 . Among the latter, AMG-333 and PF-05105679 reached phase I clinical trials for the oral treatment of cold induced pain and migraine, respectively 33 , 36 , but both studies were discontinued due to adverse secondary effects, including non-tolerated hot sensations.…”