RESUMO
The mammalian mitochondrial branched-chain ketoacid dehydrogenase (BCKD) complex is a multienzyme complex involved in the catabolism of branched-chain amino acids. BCKD is regulated by the BCKD kinase, or BCKDK, which binds to the E2 subunit of BCKD, phosphorylates its E1 subunit, and inhibits enzymatic activity. Inhibition of the BCKD complex results in increased levels of branched-chain amino acids and branched-chain ketoacids, and this buildup has been associated with heart failure, type 2 diabetes mellitus, and nonalcoholic fatty liver disease. To find BCKDK inhibitors for potential treatment of these diseases, we performed both NMR and virtual fragment screening and identified tetrazole-bearing fragments that bind BCKDK at multiple sites. Through structure-based virtual screening expanding from these fragments, the angiotensin receptor blocker class antihypertension drugs and angiotensin receptor blocker-like compounds were discovered to be potent BCKDK inhibitors, suggesting potential new avenues for heart failure treatment combining BCKDK inhibition and antihypertension.
Assuntos
3-Metil-2-Oxobutanoato Desidrogenase (Lipoamida) , Antagonistas de Receptores de Angiotensina , Humanos , 3-Metil-2-Oxobutanoato Desidrogenase (Lipoamida)/metabolismo , Aminoácidos de Cadeia Ramificada/metabolismo , Antagonistas de Receptores de Angiotensina/farmacologia , Complexos Multienzimáticos/metabolismo , Insuficiência Cardíaca , HipertensãoRESUMO
Hereditary sensory and autonomic neuropathy type IV (HSAN IV) is an autosomal recessive disorder characterized by a complete lack of pain perception and anhidrosis. Here, we studied a cohort of seven patients with HSAN IV and describe a comprehensive functional analysis of seven novel NTRK1 missense mutations, c.1550G >A, c.1565G >A, c.1970T >C, c.2096T >C, c.2254T >A, c.2288G >C, and c.2311C >T, corresponding to p.G517E, p.G522E, p.L657P, p.I699T, p.C752S, p.C763S, and p.R771C, all of which were predicted pathogenic by in silico analysis. The results allowed us to assess the pathogenicity of each mutation and to gain novel insights into tropomyosin receptor kinase A (TRKA) downstream signaling. Each mutation was systematically analyzed for TRKA glycosylation states, intracellular and cell membrane expression patterns, nerve growth factor stimulated TRKA autophosphorylation, TRKA-Y496 phosphorylation, PLCγ activity, and neurite outgrowth. We showed a diverse range of functional effects: one mutation appeared fully functional, another had partial activity in all assays, one mutation affected only the PLCγ pathway and four mutations were proved null in all assays. Thus, we conclude that complete abolition of TRKA kinase activity is not the only pathogenic mechanism underlying HSAN IV. By corollary, the assessment of the clinical pathogenicity of HSAN IV mutations is more complex than initially predicted and requires a multifaceted approach.
Assuntos
Neuropatias Hereditárias Sensoriais e Autônomas/genética , Neuropatias Hereditárias Sensoriais e Autônomas/metabolismo , Mutação de Sentido Incorreto , Receptor trkA/genética , Receptor trkA/metabolismo , Alelos , Linhagem Celular , Biologia Computacional/métodos , Análise Mutacional de DNA , Ordem dos Genes , Estudos de Associação Genética , Loci Gênicos , Predisposição Genética para Doença , Genótipo , Glicosilação , Neuropatias Hereditárias Sensoriais e Autônomas/diagnóstico , Humanos , Imagem Molecular , Neuritos/metabolismo , Fosfolipase C gama/metabolismo , Fosforilação , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Receptor trkA/química , Proteínas Recombinantes de Fusão , Análise de Sequência de DNA , Transdução de SinaisRESUMO
Optimization of ligand binding affinity to the target protein of interest is a primary objective in small-molecule drug discovery. Until now, the prediction of binding affinities by computational methods has not been widely applied in the drug discovery process, mainly because of its lack of accuracy and reproducibility as well as the long turnaround times required to obtain results. Herein we report on a collaborative study that compares tropomyosin receptor kinase A (TrkA) binding affinity predictions using two recently formulated fast computational approaches, namely, Enhanced Sampling of Molecular dynamics with Approximation of Continuum Solvent (ESMACS) and Thermodynamic Integration with Enhanced Sampling (TIES), to experimentally derived TrkA binding affinities for a set of Pfizer pan-Trk compounds. ESMACS gives precise and reproducible results and is applicable to highly diverse sets of compounds. It also provides detailed chemical insight into the nature of ligand-protein binding. TIES can predict and thus optimize more subtle changes in binding affinities between compounds of similar structure. Individual binding affinities were calculated in a few hours, exhibiting good correlations with the experimental data of 0.79 and 0.88 from the ESMACS and TIES approaches, respectively. The speed, level of accuracy, and precision of the calculations are such that the affinity predictions can be used to rapidly explain the effects of compound modifications on TrkA binding affinity. The methods could therefore be used as tools to guide lead optimization efforts across multiple prospective structurally enabled programs in the drug discovery setting for a wide range of compounds and targets.
Assuntos
Desenho de Fármacos , Dor/tratamento farmacológico , Inibidores de Proteínas Quinases/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Receptor trkA/antagonistas & inibidores , Receptor trkA/metabolismo , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Dor/enzimologia , Ligação Proteica , Inibidores de Proteínas Quinases/uso terapêutico , Receptor trkA/química , TermodinâmicaRESUMO
Selective modulators of the γ-amino butyric acid (GABAA) family of receptors have the potential to treat a range of disease states related to cognition, pain, and anxiety. While the development of various α subunit-selective modulators is currently underway for the treatment of anxiety disorders, a mechanistic understanding of the correlation between their bioactivity and efficacy, based on ligand-target interactions, is currently still lacking. In order to alleviate this situation, in the current study we have analyzed, using ligand- and structure-based methods, a data set of 5440 GABAA modulators. The Spearman correlation (ρ) between binding activity and efficacy of compounds was calculated to be 0.008 and 0.31 against the α1 and α2 subunits of GABA receptor, respectively; in other words, the compounds had little diversity in structure and bioactivity, but they differed significantly in efficacy. Two compounds were selected as a case study for detailed interaction analysis due to the small difference in their structures and affinities (ΔpKi(comp1_α1 - comp2_α1) = 0.45 log units, ΔpKi(comp1_α2 - comp2_α2) = 0 log units) as compared to larger relative efficacies (ΔRE(comp1_α1 - comp2_α1) = 1.03, ΔRE(comp1_α2 - comp2_α2) = 0.21). Docking analysis suggested that His-101 is involved in a characteristic interaction of the α1 receptor with both compounds 1 and 2. Residues such as Phe-77, Thr-142, Asn-60, and Arg-144 of the γ chain of the α1γ2 complex also showed interactions with heterocyclic rings of both compounds 1 and 2, but these interactions were disturbed in the case of α2γ2 complex docking results. Binding pocket stability analysis based on molecular dynamics identified three substitutions in the loop C region of the α2 subunit, namely, G200E, I201T, and V202I, causing a reduction in the flexibility of α2 compared to α1. These amino acids in α2, as compared to α1, were also observed to decrease the vibrational and dihedral entropy and to increase the hydrogen bond content in α2 in the apo state. However, freezing of both α1 and α2 was observed in the ligand-bound state, with an increased number of internal hydrogen bonds and increased entropy. Therefore, we hypothesize that the amino acid differences in the loop C region of α2 are responsible for conformational changes in the protein structure compared to α1, as well as for the binding modes of compounds and hence their functional signaling.
Assuntos
Receptores de GABA/metabolismo , Sequência de Aminoácidos , Animais , Benzodiazepinas/farmacologia , Ácido Butírico/farmacologia , Agonistas de Receptores de GABA-A/farmacologia , Humanos , Ligação de Hidrogênio , Simulação de Dinâmica Molecular , Dados de Sequência Molecular , Análise de Componente Principal , Estrutura Secundária de Proteína , Receptores de GABA/químicaRESUMO
TRESK (Twik RElated Spinal cord K+ channel) is a member of the Twin Pore Domain potassium channel (K2P) family responsible for regulating neuronal excitability in dorsal root ganglion (DRG) and trigeminal (TG) neurons, peripheral neurons involved in pain transmission. As channel opening causes an outward K+ current responsible for cell hyperpolarisation, TRESK represents a potentially interesting target for pain treatment. However, as no crystal structure exists for this protein, the mechanisms involved in the opening action of its ligands are still poorly understood, making the development of new potent and selective openers challenging. In this work we present a structure activity relationship (SAR) of the known TRESK opener flufenamic acid (FFA) and some derivatives, investigating the functional effects of chemical modifications to build a TRESK homology model to support the biological results. A plausible binding mode is proposed, providing the first predictive hypothesis of a human TRESK opener binding site.
Assuntos
Ácido Flufenâmico/química , Ácido Flufenâmico/farmacologia , Canais de Potássio/química , Animais , Sítios de Ligação , Células HEK293 , Humanos , Camundongos , Neurônios/efeitos dos fármacos , Relação Estrutura-AtividadeRESUMO
Voltage-gated potassium channels of the Kv1 family play a crucial role in the generation and transmission of electrical signals in excitable cells affecting neuronal and cardiac activities. Small-molecule blockage of these channels has been proposed to occur via a cooperative mechanism involving two main blocking sites: the inner-pore site located below the selectivity filter, and a side-pocket cavity located between the pore and the voltage sensor. Using 0.5 µs molecular dynamics simulation trajectories complemented by docking calculations, the potential binding sites of the PAP-1 (5-(4-phenoxybutoxy)psoralen) blocker to the crystal structure of Kv1.2 channel have been studied. The presence of both mentioned blocking sites at Kv1.2 is confirmed, adding evidence in favor of a cooperative channel blockage mechanism. These observations provide insight into drug modulation that will guide further developments of Kv inhibitors.
Assuntos
Ficusina/química , Canal de Potássio Kv1.2/química , Sequência de Aminoácidos , Animais , Sítios de Ligação , Análise por Conglomerados , Cristalização , Eletroquímica , Humanos , Ligantes , Simulação de Dinâmica Molecular , Dados de Sequência Molecular , Neurônios/patologia , Proteínas Associadas a Pancreatite , Ratos , Homologia de Sequência de Aminoácidos , Solventes/químicaRESUMO
TWIK-related K(+) 1 (TREK1) potassium channels are members of the two-pore domain potassium channel family and contribute to background potassium conductances in many cell types, where their activity can be regulated by a variety of physiologic and pharmacologic mediators. Fenamates such as FFA (flufenamic acid; 2-{[3-(trifluoromethyl)phenyl]amino}benzoic acid), MFA [mefenamic acid; 2-(2,3-dimethylphenyl)aminobenzoic acid], NFA [niflumic acid; 2-{[3-(trifluoromethyl)phenyl]amino}nicotinic acid], and diclofenac [2-(2-(2,6-dichlorophenylamino)phenyl)acetic acid] and the related experimental drug BL-1249 [(5,6,7,8-tetrahydro-naphthalen-1-yl)-[2-(1H-tetrazol-5-yl)-phenyl]-amine] enhance the activity of TREK1 currents, and we show that BL-1249 is the most potent of these compounds. Alternative translation initiation produces a shorter, N terminus truncated form of TREK1 with a much reduced open probability and a proposed increased permeability to sodium compared with the longer form. We show that both forms of TREK1 can be activated by fenamates and that a number of mutations that affect TREK1 channel gating occlude the action of fenamates but only in the longer form of TREK1. Furthermore, fenamates produce a marked enhancement of current through the shorter, truncated form of TREK1 and reveal a K(+)-selective channel, like the long form. These results provide insight into the mechanism of TREK1 channel activation by fenamates, and, given the role of TREK1 channels in pain, they suggest a novel analgesic mechanism for these compounds.
Assuntos
Fenamatos/farmacologia , Canais de Potássio de Domínios Poros em Tandem/agonistas , Canais de Potássio de Domínios Poros em Tandem/fisiologia , Células HEK293 , Humanos , Ativação do Canal Iônico/efeitos dos fármacos , Ativação do Canal Iônico/fisiologia , Mutação/fisiologia , Canais de Potássio de Domínios Poros em Tandem/química , Estrutura Secundária de ProteínaRESUMO
The melanocortin-4 receptor (MC4R) is a centrally expressed, class A GPCR that plays a key role in the regulation of appetite and food intake. Deficiencies in MC4R signaling result in hyperphagia and increased body mass in humans. Antagonism of MC4R signaling has the potential to mitigate decreased appetite and body weight loss in the setting of anorexia or cachexia due to underlying disease. Herein, we report on the identification of a series of orally bioavailable, small-molecule MC4R antagonists using a focused hit identification effort and the optimization of these antagonists to provide clinical candidate 23. Introduction of a spirocyclic conformational constraint allowed for simultaneous optimization of MC4R potency and ADME attributes while avoiding the production of hERG active metabolites observed in early series leads. Compound 23 is a potent and selective MC4R antagonist with robust efficacy in an aged rat model of cachexia and has progressed into clinical trials.
Assuntos
Apetite , Receptor Tipo 4 de Melanocortina , Ratos , Humanos , Animais , Caquexia/tratamento farmacológico , Anorexia/tratamento farmacológico , Conformação MolecularRESUMO
Branched chain amino acid (BCAA) catabolic impairments have been implicated in several diseases. Branched chain ketoacid dehydrogenase (BCKDH) controls the rate limiting step in BCAA degradation, the activity of which is inhibited by BCKDH kinase (BDK)-mediated phosphorylation. Screening efforts to discover BDK inhibitors led to identification of thiophene PF-07208254, which improved cardiometabolic endpoints in mice. Structure-activity relationship studies led to identification of a thiazole series of BDK inhibitors; however, these inhibitors did not improve metabolism in mice upon chronic administration. While the thiophenes demonstrated sustained branched chain ketoacid (BCKA) lowering and reduced BDK protein levels, the thiazoles increased BCKAs and BDK protein levels. Thiazoles increased BDK proximity to BCKDH-E2, whereas thiophenes reduced BDK proximity to BCKDH-E2, which may promote BDK degradation. Thus, we describe two BDK inhibitor series that possess differing attributes regarding BDK degradation or stabilization and provide a mechanistic understanding of the desirable features of an effective BDK inhibitor.
Assuntos
Aminoácidos de Cadeia Ramificada , Tiofenos , Camundongos , Animais , Aminoácidos de Cadeia Ramificada/metabolismo , Fosforilação , Tiofenos/farmacologia , Oxirredutases/metabolismoRESUMO
Aldehyde oxidase (AO) is a molybdenum-containing enzyme distributed throughout the animal kingdom and capable of metabolising a wide range of aldehydes and N-heterocyclic compounds. Although metabolism by this enzyme in man is recognised to have significant clinical impact where human AO activity was not predicted by screening in preclinical species, there is very little reported literature offering real examples where drug discoverers have successfully designed away from AO oxidation. This article reports on some strategies adopted in the Pfizer TLR7 agonist programme to successfully switch off AO metabolism that was seen principally in the rat.
Assuntos
Aldeído Oxidase/metabolismo , Piridinas/síntese química , Aldeído Oxidase/antagonistas & inibidores , Aldeído Oxidase/química , Animais , Células Cultivadas , Química Farmacêutica , Citosol/enzimologia , Cães , Estabilidade de Medicamentos , Humanos , Masculino , Piridinas/química , Ratos , Relação Estrutura-Atividade , Receptor 7 Toll-Like/agonistasRESUMO
TrpA1 is an ion channel involved in nociceptive and inflammatory pain. It is implicated in the detection of chemical irritants through covalent binding to a cysteine-rich intracellular region of the protein. While performing an HTS of the Pfizer chemical collection, a class of pyrimidines emerged as a non-reactive, non-covalently binding family of agonists of the rat and human TrpA1 channel. Given the issues identified with the reference agonist Mustard Oil (MO) in screening, a new, non-covalently binding agonist was optimized and proved to be a superior agent to MO for screening purposes. Compound 16a (PF-4840154) is a potent, selective agonist of the rat and human TrpA1 channel and elicited TrpA1-mediated nocifensive behaviour in mouse.
Assuntos
Anquirinas/agonistas , Desenho de Fármacos , Proteínas do Tecido Nervoso/agonistas , Piperazinas/farmacologia , Pirimidinas/farmacologia , Canais de Potencial de Receptor Transitório/agonistas , Animais , Canais de Cálcio , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Edema/tratamento farmacológico , Edema/fisiopatologia , Humanos , Camundongos , Camundongos Knockout , Estrutura Molecular , Dor/tratamento farmacológico , Dor/fisiopatologia , Piperazinas/síntese química , Piperazinas/química , Pirimidinas/síntese química , Pirimidinas/química , Ratos , Estereoisomerismo , Relação Estrutura-Atividade , Canal de Cátion TRPA1 , Canais de Cátion TRPCRESUMO
Fibroblast growth factor receptors (FGFR) 2 and 3 have been established as drivers of numerous types of cancer with multiple drugs approved or entering late stage clinical trials. A limitation of current inhibitors is vulnerability to gatekeeper resistance mutations. Using a combination of targeted high-throughput screening and structure-based drug design, we have developed a series of aminopyrazole based FGFR inhibitors that covalently target a cysteine residue on the P-loop of the kinase. The inhibitors show excellent activity against the wild-type and gatekeeper mutant versions of the enzymes. Further optimization using SAR analysis and structure-based drug design led to analogues with improved potency and drug metabolism and pharmacokinetics properties.
RESUMO
Carbamoyl phosphate synthetase 1 (CPS1) is a potential synthetic lethal target in LKB1-deficient nonsmall cell lung cancer, where its overexpression supports the production of pyrimidine synthesis. In other cancer types, CPS1 overexpression and activity may prevent the accumulation of toxic levels of intratumoral ammonia to support tumor growth. Herein we report the discovery of a novel series of potent and selective small-molecule inhibitors of CPS1. Piperazine 2 was initially identified as a promising CPS1 inhibitor through a high-throughput screening effort. Subsequent structure-activity relationship optimization and structure-based drug design led to the discovery of piperazine H3B-616 (25), a potent allosteric inhibitor of CPS1 (IC50 = 66 nM).
RESUMO
Carbamoyl phosphate synthetase 1 (CPS1) catalyzes the first step in the ammonia-detoxifying urea cycle, converting ammonia to carbamoyl phosphate under physiologic conditions. In cancer, CPS1 overexpression supports pyrimidine synthesis to promote tumor growth in some cancer types, while in others CPS1 activity prevents the buildup of toxic levels of intratumoral ammonia to allow for sustained tumor growth. Targeted CPS1 inhibitors may, therefore, provide a therapeutic benefit for cancer patients with tumors overexpressing CPS1. Herein, we describe the discovery of small-molecule CPS1 inhibitors that bind to a previously unknown allosteric pocket to block ATP hydrolysis in the first step of carbamoyl phosphate synthesis. CPS1 inhibitors are active in cellular assays, blocking both urea synthesis and CPS1 support of the pyrimidine biosynthetic pathway, while having no activity against CPS2. These newly discovered CPS1 inhibitors are a first step toward providing researchers with valuable tools for probing CPS1 cancer biology.
Assuntos
Carbamoil-Fosfato Sintase (Amônia)/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Piperidinas/farmacologia , Bibliotecas de Moléculas Pequenas/farmacologia , Tiazóis/farmacologia , Trifosfato de Adenosina/antagonistas & inibidores , Trifosfato de Adenosina/metabolismo , Regulação Alostérica/efeitos dos fármacos , Carbamoil-Fosfato Sintase (Amônia)/genética , Carbamoil-Fosfato Sintase (Amônia)/metabolismo , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/química , Humanos , Hidrólise/efeitos dos fármacos , Modelos Moleculares , Estrutura Molecular , Piperidinas/química , Bibliotecas de Moléculas Pequenas/química , Tiazóis/químicaRESUMO
The design, optimization, and evaluation of a series of novel imidazopyridazine-based subtype-selective positive allosteric modulators (PAMs) for the GABAA ligand-gated ion channel are described. From a set of initial hits multiple subseries were designed and evaluated based on binding affinity and functional activity. As designing in the desired level of functional selectivity proved difficult, a probability-based assessment was performed to focus the project's efforts on a single subseries that had the greatest odds of delivering the target profile. These efforts ultimately led to the identification of two precandidates from this subseries, which were advanced to preclinical safety studies and subsequently to the identification of the clinical candidate PF-06372865.
Assuntos
Desenho de Fármacos , Imidazóis/farmacologia , Piridazinas/farmacologia , Receptores de GABA-A/metabolismo , Regulação Alostérica/efeitos dos fármacos , Humanos , Imidazóis/química , Piridazinas/químicaRESUMO
Tropomyosin receptor kinases (TrkA, TrkB, TrkC) are activated by hormones of the neurotrophin family: nerve growth factor (NGF), brain derived neurotrophic factor (BDNF), neurotrophin 3 (NT3), and neurotrophin 4 (NT4). Moreover, the NGF antibody tanezumab has provided clinical proof of concept for inhibition of the TrkA kinase pathway in pain leading to significant interest in the development of small molecule inhibitors of TrkA. However, achieving TrkA subtype selectivity over TrkB and TrkC via a Type I and Type II inhibitor binding mode has proven challenging and Type III or Type IV allosteric inhibitors may present a more promising selectivity design approach. Furthermore, TrkA inhibitors with minimal brain availability are required to deliver an appropriate safety profile. Herein, we describe the discovery of a highly potent, subtype selective, peripherally restricted, efficacious, and well-tolerated series of allosteric TrkA inhibitors that culminated in the delivery of candidate quality compound 23.
Assuntos
Inibidores de Proteínas Quinases/química , Receptor trkA/antagonistas & inibidores , Regulação Alostérica , Sequência de Aminoácidos , Animais , Sítios de Ligação , Cristalografia por Raios X , Avaliação Pré-Clínica de Medicamentos , Meia-Vida , Ensaios de Triagem em Larga Escala , Humanos , Ligantes , Microssomos Hepáticos/metabolismo , Simulação de Dinâmica Molecular , Ligação Proteica , Isoformas de Proteínas/antagonistas & inibidores , Isoformas de Proteínas/metabolismo , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/farmacocinética , Estrutura Terciária de Proteína , Pirazóis/síntese química , Pirazóis/química , Pirazóis/farmacocinética , Ratos , Receptor trkA/metabolismo , Alinhamento de Sequência , Relação Estrutura-AtividadeRESUMO
Benzimidazolone derivatives were discovered as novel CB2 selective agonists. Structure Activity Relationship (SAR) studies around them were examined to improve metabolic stability. Compound 39 exhibited excellent metabolic stability in human liver microsomes (HLM) and significant attenuation of the chronic colonic allodynia in the TNBS-treated rats by po administration.
Assuntos
Benzimidazóis/síntese química , Benzimidazóis/farmacologia , Receptor CB2 de Canabinoide/agonistas , Animais , Benzimidazóis/química , Técnicas de Química Combinatória , Desenho de Fármacos , Humanos , Estrutura Molecular , Ratos , Receptor CB1 de Canabinoide/agonistas , Relação Estrutura-AtividadeRESUMO
BACKGROUND AND PURPOSE: TREK two-pore-domain potassium (K2P ) channels play a critical role in regulating the excitability of somatosensory nociceptive neurons and are important mediators of pain perception. An understanding of the roles of TREK channels in pain perception and, indeed, in other pathophysiological conditions, has been severely hampered by the lack of potent and/or selective activators and inhibitors. In this study, we describe a new, selective opener of TREK channels, GI-530159. EXPERIMENTAL APPROACH: The effect of GI-530159 on TREK channels was demonstrated using 86 Rb efflux assays, whole-cell and single-channel patch-clamp recordings from recombinant TREK channels. The expression of K2P 2.1 (TREK1), K2P 10.1 (TREK2) and K2P 4.1 (TRAAK) channels was determined using transcriptome analysis from single dorsal root ganglion (DRG) cells. Current-clamp recordings from cultured rat DRG neurons were used to measure the effect of GI-530159 on neuronal excitability. KEY RESULTS: For recombinant human TREK1 channels, GI-530159 had similar low EC50 values in Rb efflux experiments and electrophysiological recordings. It activated TREK2 channels, but it had no detectable action on TRAAK channels nor any significant effect on other K channels tested. Current-clamp recordings from cultured rat DRG neurones showed that application of GI-530159 at 1 µM resulted in a significant reduction in firing frequency and a small hyperpolarization of resting membrane potential. CONCLUSIONS AND IMPLICATIONS: This study provides pharmacological evidence for the presence of mechanosensitive TREK K2P channels in sensory neurones and suggests that development of selective K2P channel openers like GI-530159 could aid in the development of novel analgesic agents. LINKED ARTICLES: This article is part of a themed section on Recent Advances in Targeting Ion Channels to Treat Chronic Pain. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.12/issuetoc.
Assuntos
Gânglios Espinais/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Canais de Potássio de Domínios Poros em Tandem/agonistas , Animais , Células CHO , Linhagem Celular , Cricetulus , Relação Dose-Resposta a Droga , Gânglios Espinais/metabolismo , Células HEK293 , Humanos , Estrutura Molecular , Neurônios/metabolismo , Ratos , Relação Estrutura-AtividadeRESUMO
Hormones of the neurotrophin family, nerve growth factor (NGF), brain derived neurotrophic factor (BDNF), neurotrophin 3 (NT3), and neurotrophin 4 (NT4), are known to activate the family of Tropomyosin receptor kinases (TrkA, TrkB, and TrkC). Moreover, inhibition of the TrkA kinase pathway in pain has been clinically validated by the NGF antibody tanezumab, leading to significant interest in the development of small molecule inhibitors of TrkA. Furthermore, Trk inhibitors having an acceptable safety profile will require minimal brain availability. Herein, we discuss the discovery of two potent, selective, peripherally restricted, efficacious, and well-tolerated series of pan-Trk inhibitors which successfully delivered three candidate quality compounds 10b, 13b, and 19. All three compounds are predicted to possess low metabolic clearance in human that does not proceed via aldehyde oxidase-catalyzed reactions, thus addressing the potential clearance prediction liability associated with our current pan-Trk development candidate PF-06273340.