RESUMO
Adaptor protein 2-associated kinase 1 (AAK1) is a member of the Ark1/Prk1 family of serine/threonine kinases and plays a role in modulating receptor endocytosis. AAK1 was identified as a potential therapeutic target for the treatment of neuropathic pain when it was shown that AAK1 knock out (KO) mice had a normal response to the acute pain phase of the mouse formalin model, but a reduced response to the persistent pain phase. Herein we report our early work investigating a series of pyrrolo[2,1-f][1,2,4]triazines as part of our efforts to recapitulate this KO phenotype with a potent, small molecule inhibitor of AAK1. The synthesis, structure-activity relationships (SAR), and in vivo evaluation of these AAK1 inhibitors is described.
RESUMO
To identify novel targets for neuropathic pain, 3097 mouse knockout lines were tested in acute and persistent pain behavior assays. One of the lines from this screen, which contained a null allele of the adapter protein-2 associated kinase 1 (AAK1) gene, had a normal response in acute pain assays (hot plate, phase I formalin), but a markedly reduced response to persistent pain in phase II formalin. AAK1 knockout mice also failed to develop tactile allodynia following the Chung procedure of spinal nerve ligation (SNL). Based on these findings, potent, small-molecule inhibitors of AAK1 were identified. Studies in mice showed that one such inhibitor, LP-935509, caused a reduced pain response in phase II formalin and reversed fully established pain behavior following the SNL procedure. Further studies showed that the inhibitor also reduced evoked pain responses in the rat chronic constriction injury (CCI) model and the rat streptozotocin model of diabetic peripheral neuropathy. Using a nonbrain-penetrant AAK1 inhibitor and local administration of an AAK1 inhibitor, the relevant pool of AAK1 for antineuropathic action was found to be in the spinal cord. Consistent with these results, AAK1 inhibitors dose-dependently reduced the increased spontaneous neural activity in the spinal cord caused by CCI and blocked the development of windup induced by repeated electrical stimulation of the paw. The mechanism of AAK1 antinociception was further investigated with inhibitors of α2 adrenergic and opioid receptors. These studies showed that α2 adrenergic receptor inhibitors, but not opioid receptor inhibitors, not only prevented AAK1 inhibitor antineuropathic action in behavioral assays, but also blocked the AAK1 inhibitor-induced reduction in spinal neural activity in the rat CCI model. Hence, AAK1 inhibitors are a novel therapeutic approach to neuropathic pain with activity in animal models that is mechanistically linked (behaviorally and electrophysiologically) to α2 adrenergic signaling, a pathway known to be antinociceptive in humans.
Assuntos
Neuralgia/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Animais , Fenômenos Eletrofisiológicos/efeitos dos fármacos , Técnicas de Inativação de Genes , Células HEK293 , Humanos , Masculino , Camundongos , Neuralgia/metabolismo , Neuralgia/fisiopatologia , Nociceptividade/efeitos dos fármacos , Fenótipo , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Serina-Treonina Quinases/deficiência , Proteínas Serina-Treonina Quinases/genética , Ratos , Medula Espinal/efeitos dos fármacos , Medula Espinal/enzimologia , Medula Espinal/fisiopatologiaRESUMO
The identification of VHL-binding proteolysis targeting chimeras (PROTACs) that potently degrade the BRM protein (also known as SMARCA2) in SW1573 cell-based experiments is described. These molecules exhibit between 10- and 100-fold degradation selectivity for BRM over the closely related paralog protein BRG1 (SMARCA4). They also selectively impair the proliferation of the H1944 "BRG1-mutant" NSCLC cell line, which lacks functional BRG1 protein and is thus highly dependent on BRM for growth, relative to the wild-type Calu6 line. In vivo experiments performed with a subset of compounds identified PROTACs that potently and selectively degraded BRM in the Calu6 and/or the HCC2302 BRG1 mutant NSCLC xenograft models and also afforded antitumor efficacy in the latter system. Subsequent PK/PD analysis established a need to achieve strong BRM degradation (>95%) in order to trigger meaningful antitumor activity in vivo. Intratumor quantitation of mRNA associated with two genes whose transcription was controlled by BRM (PLAU and KRT80) also supported this conclusion.
Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Quimera de Direcionamento de Proteólise , Xenoenxertos , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular , Neoplasias Pulmonares/genética , Fatores de Transcrição/genética , DNA Helicases/genética , Proteínas Nucleares/genéticaRESUMO
The mammalian SWItch/Sucrose Non-Fermentable (SWI/SNF) helicase SMARCA4 is frequently mutated in cancer and inactivation results in a cellular dependence on its paralog, SMARCA2, thus making SMARCA2 an attractive synthetic lethal target. However, published data indicates that achieving a high degree of selective SMARCA2 inhibition is likely essential to afford an acceptable therapeutic index, and realizing this objective is challenging due to the homology with the SMARCA4 paralog. Herein we report the discovery of a potent and selective SMARCA2 proteolysis-targeting chimera molecule (PROTAC), A947. Selective SMARCA2 degradation is achieved in the absence of selective SMARCA2/4 PROTAC binding and translates to potent in vitro growth inhibition and in vivo efficacy in SMARCA4 mutant models, compared to wild type models. Global ubiquitin mapping and proteome profiling reveal no unexpected off-target degradation related to A947 treatment. Our study thus highlights the ability to transform a non-selective SMARCA2/4-binding ligand into a selective and efficacious in vivo SMARCA2-targeting PROTAC, and thereby provides a potential new therapeutic opportunity for patients whose tumors contain SMARCA4 mutations.
Assuntos
Neoplasias , Animais , Humanos , Proteólise , Neoplasias/genética , Mutação , Mamíferos , Fatores de Transcrição/genética , DNA Helicases/genética , Proteínas Nucleares/genéticaRESUMO
Adaptor protein 2-associated kinase 1 (AAK1) is a serine/threonine kinase that was identified as a therapeutic target for the potential treatment of neuropathic pain. Inhibition of AAK1 in the central nervous system, particularly within the spinal cord, was found to be the relevant site for achieving an antinociceptive effect. We previously reported that compound 7 is a brain-penetrant, AAK1 inhibitor that showed efficacy in animal models for neuropathic pain. One approach we took to improve upon the potency of 7 involved tying the amide back into the neighboring phenyl ring to form a bicyclic heterocycle. Investigation of the structure-activity relationships (SARs) of substituents on the resultant quinazoline and quinoline ring systems led to the identification of (S)-31, a brain-penetrant, AAK1-selective inhibitor with improved enzyme and cellular potency compared to 7. The synthesis, SAR, and in vivo evaluation of a series of quinazoline and quinoline-based AAK1 inhibitors are described herein.
Assuntos
Neuralgia , Quinolinas , Amidas/farmacologia , Amidas/uso terapêutico , Animais , Neuralgia/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Quinazolinas/uso terapêutico , Quinolinas/farmacologia , Quinolinas/uso terapêutico , Relação Estrutura-AtividadeRESUMO
Recent mouse knockout studies identified adapter protein-2-associated kinase 1 (AAK1) as a viable target for treating neuropathic pain. BMS-986176/LX-9211 (4), as a highly selective, CNS-penetrable, and potent AAK1 inhibitor, has advanced into phase II human trials. On exploring the structure-activity relationship (SAR) around this biaryl alkyl ether chemotype, several additional compounds were found to be highly selective and potent AAK1 inhibitors with good druglike properties. Among these, compounds 43 and 58 showed very good efficacy in two neuropathic pain rat models and had excellent CNS penetration and spinal cord target engagement. Both compounds also exhibited favorable physicochemical and oral pharmacokinetic (PK) properties. Compound 58, a central pyridine isomer of BMS-986176/LX-9211 (4), was 4-fold more potent than 4 in vitro and showed lower plasma exposure needed to achieve similar efficacy compared to 4 in the CCI rat model. However, both 43 and 58 showed an inferior preclinical toxicity profile compared to 4.
Assuntos
Anestésicos Gerais , Neuralgia , Animais , Éteres/uso terapêutico , Camundongos , Neuralgia/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Ratos , Medula Espinal , Relação Estrutura-AtividadeRESUMO
Recent mouse knockout studies identified adapter protein-2 associated kinase 1 (AAK1) as a viable target for treating neuropathic pain. Potent small-molecule inhibitors of AAK1 have been identified and show efficacy in various rodent pain models. (S)-1-((2',6-Bis(difluoromethyl)-[2,4'-bipyridin]-5-yl)oxy)-2,4-dimethylpentan-2-amine (BMS-986176/LX-9211) (34) was identified as a highly selective, CNS penetrant, potent AAK1 inhibitor from a novel class of bi(hetero)aryl ethers. BMS-986176/LX9211 (34) showed excellent efficacy in two rodent neuropathic pain models and excellent central nervous system (CNS) penetration and target engagement at the spinal cord with an average brain to plasma ratio of 20 in rat. The compound exhibited favorable physicochemical and pharmacokinetic properties, had an acceptable preclinical toxicity profile, and was chosen for clinical trials. BMS-986176/LX9211 (34) completed phase I trials with good human pharmacokinetics and minimum adverse events and is currently in phase II clinical trials for diabetic peripheral neuropathic pain (ClinicalTrials.gov identifier: NCT04455633) and postherpetic neuralgia (ClinicalTrials.gov identifier: NCT04662281).
Assuntos
Aminas , Neuralgia , Animais , Encéfalo , Camundongos , Neuralgia/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Ratos , Medula EspinalRESUMO
Effective treatment of chronic pain, in particular neuropathic pain, without the side effects that often accompany currently available treatment options is an area of significant unmet medical need. A phenotypic screen of mouse gene knockouts led to the discovery that adaptor protein 2-associated kinase 1 (AAK1) is a potential therapeutic target for neuropathic pain. The synthesis and optimization of structure-activity relationships of a series of aryl amide-based AAK1 inhibitors led to the identification of 59, a brain penetrant, AAK1-selective inhibitor that proved to be a valuable tool compound. Compound 59 was evaluated in mice for the inhibition of µ2 phosphorylation. Studies conducted with 59 in pain models demonstrated that this compound was efficacious in the phase II formalin model for persistent pain and the chronic-constriction-injury-induced model for neuropathic pain in rats. These results suggest that AAK1 inhibition is a promising approach for the treatment of neuropathic pain.
Assuntos
Amidas/farmacologia , Anti-Inflamatórios não Esteroides/farmacologia , Encéfalo/enzimologia , Neuralgia/tratamento farmacológico , Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Amidas/síntese química , Amidas/química , Animais , Anti-Inflamatórios não Esteroides/síntese química , Anti-Inflamatórios não Esteroides/química , Células CACO-2 , Relação Dose-Resposta a Droga , Descoberta de Drogas , Células HEK293 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microssomos Hepáticos/química , Microssomos Hepáticos/metabolismo , Estrutura Molecular , Neuralgia/metabolismo , Proteínas Quinases/síntese química , Proteínas Quinases/química , Proteínas Serina-Treonina Quinases/metabolismo , Relação Estrutura-AtividadeRESUMO
PROteolysis-TArgeting Chimeras (PROTACs) are hetero-bifunctional molecules that recruit an E3 ubiquitin ligase to a given substrate protein resulting in its targeted degradation. Many potent PROTACs with specificity for dissimilar targets have been developed; however, the factors governing degradation selectivity within closely-related protein families remain elusive. Here, we generate isoform-selective PROTACs for the p38 MAPK family using a single warhead (foretinib) and recruited E3 ligase (von Hippel-Lindau). Based on their distinct linker attachments and lengths, these two PROTACs differentially recruit VHL, resulting in degradation of p38α or p38δ. We characterize the role of ternary complex formation in driving selectivity, showing that it is necessary, but insufficient, for PROTAC-induced substrate ubiquitination. Lastly, we explore the p38δ:PROTAC:VHL complex to explain the different selectivity profiles of these PROTACs. Our work attributes the selective degradation of two closely-related proteins using the same warhead and E3 ligase to heretofore underappreciated aspects of the ternary complex model.
Assuntos
Bibliotecas de Moléculas Pequenas/farmacologia , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação/efeitos dos fármacos , Proteína Supressora de Tumor Von Hippel-Lindau/metabolismo , Humanos , Modelos Moleculares , Estrutura Molecular , Domínios Proteicos , Proteólise/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/química , Especificidade por Substrato , Ubiquitina-Proteína Ligases/química , Proteína Supressora de Tumor Von Hippel-Lindau/química , Proteínas Quinases p38 Ativadas por Mitógeno/química , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
Fluorescence resonance energy transfer (FRET) has emerged as a powerful tool to the study of protein-protein interactions, such as receptor-ligand binding. However, the application of FRET to the study of G protein-coupled receptors (GPCRs) has been limited by the method of labeling receptor with fluorescence probes. Here we described a novel time-resolved (TR)-FRET method to study GPCR-ligand binding by using human complement 5a (C5a) receptor (C5aR) as a model system. Human C5aR was expressed in human embryonic kidney 293 cells with a hemagglutinin (HA) epitope at the N-terminus. Purified human C5a was labeled with terbium chelate and used as the fluorescence donor. Monoclonal anti-HA antibody conjugated with Alexa Fluor 488 was used as the fluorescence acceptor. Robust FRET signal was observed when the labeled ligand and C5aR membrane were mixed in the presence of the conjugated anti-HA antibody. This FRET signal was specific and saturable. C5a binding affinity to C5aR measured by the FRET assay was consistent with the data as determined by competition binding analysis using radiolabeled C5a. The FRET assay was also used to determine affinity of C5aR antagonists by competition binding analysis, and the data are similar to those from radioligand binding studies. Compared to the commonly used radioligand binding assay, this TR-FRET-based assay provides a nonradioactive, faster, and sensitive homogeneous assay format that could be easily adapted to high-throughput screening. The principle of this assay should also be applicable to other GPCRs, especially to those receptors with peptide or protein ligands.
Assuntos
Transferência Ressonante de Energia de Fluorescência/métodos , Receptores Acoplados a Proteínas G/metabolismo , Linhagem Celular , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Quelantes/química , Complemento C5a/química , AMP Cíclico/metabolismo , Humanos , Ligantes , Ensaio Radioligante , Receptor da Anafilatoxina C5a/antagonistas & inibidores , Térbio/químicaRESUMO
Inhibiting protein function selectively is a major goal of modern drug discovery. Here, we report a previously understudied benefit of small molecule proteolysis-targeting chimeras (PROTACs) that recruit E3 ubiquitin ligases to target proteins for their ubiquitination and subsequent proteasome-mediated degradation. Using promiscuous CRBN- and VHL-recruiting PROTACs that bind >50 kinases, we show that only a subset of bound targets is degraded. The basis of this selectivity relies on protein-protein interactions between the E3 ubiquitin ligase and the target protein, as illustrated by engaged proteins that are not degraded as a result of unstable ternary complexes with PROTAC-recruited E3 ligases. In contrast, weak PROTAC:target protein affinity can be stabilized by high-affinity target:PROTAC:ligase trimer interactions, leading to efficient degradation. This study highlights design guidelines for generating potent PROTACs as well as possibilities for degrading undruggable proteins immune to traditional small-molecule inhibitors.
Assuntos
Desenho de Fármacos , Complexo de Endopeptidases do Proteassoma/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Bibliotecas de Moléculas Pequenas/farmacologia , Ubiquitina-Proteína Ligases/antagonistas & inibidores , Humanos , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Proteólise/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/síntese química , Bibliotecas de Moléculas Pequenas/química , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação/efeitos dos fármacosRESUMO
Proteolysis targeting chimeras (PROTACs) are bifunctional molecules that recruit an E3 ligase to a target protein to facilitate ubiquitination and subsequent degradation of that protein. While the field of targeted degraders is still relatively young, the potential for this modality to become a differentiated and therapeutic reality is strong, such that both academic and pharmaceutical institutions are now entering this interesting area of research. In this article, we describe a broadly applicable process for identifying degrader hits based on the serine/threonine kinase TANK-binding kinase 1 (TBK1) and have generalized the key structural elements associated with degradation activities. Compound 3i is a potent hit (TBK1 DC50 = 12 nM, Dmax = 96%) with excellent selectivity against a related kinase IKKε, which was further used as a chemical tool to assess TBK1 as a target in mutant K-Ras cancer cells.
Assuntos
Proteínas Serina-Treonina Quinases/metabolismo , Proteólise/efeitos dos fármacos , Proteína Supressora de Tumor Von Hippel-Lindau/metabolismo , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Técnicas de Química Sintética , Polarização de Fluorescência , Genes ras , Humanos , Quinase I-kappa B/genética , Quinase I-kappa B/metabolismo , Estrutura Molecular , Mutação , Proteínas Serina-Treonina Quinases/genética , Interferência de RNA , Relação Estrutura-Atividade , Proteína Supressora de Tumor Von Hippel-Lindau/química , Proteína Supressora de Tumor Von Hippel-Lindau/genéticaRESUMO
The first allosteric, type III inhibitor of LIM-kinase 2 (LIMK2) is reported. A series of molecules that feature both an N-phenylsulfonamide and tertiary amide were not only very potent at LIMK2 but also were extremely selective against a panel of other kinases. Enzymatic kinetic studies showed these molecules to be noncompetitive with ATP, suggesting allosteric inhibition. X-ray crystallography confirmed that these sulfonamides are a rare example of a type III kinase inhibitor that binds away from the highly conserved hinge region and instead resides in the hydrophobic pocket formed in the DFG-out conformation of the kinase, thus accounting for the high level of selectivity observed.
RESUMO
The structure of LX7101, a dual LIM-kinase and ROCK inhibitor for the treatment of ocular hypertension and associated glaucoma, is disclosed. Previously reported LIM kinase inhibitors suffered from poor aqueous stability due to solvolysis of the central urea. Replacement of the urea with a hindered amide resulted in aqueous stable compounds, and addition of solubilizing groups resulted in a set of compounds with good properties for topical dosing in the eye and good efficacy in a mouse model of ocular hypertension. LX7101 was selected as a clinical candidate from this group based on superior efficacy in lowering intraocular pressure and a good safety profile. LX7101 completed IND enabling studies and was tested in a Phase 1 clinical trial in glaucoma patients, where it showed efficacy in lowering intraocular pressure.
RESUMO
Pleckstrin homology (PH) domains are present in key proteins involved in many vital cell processes. For example, the PH domain of Bruton's tyrosine kinase (Btk) binds to phosphatidylinositol triphosphate (PIP(3)) in the plasma membrane after stimulation of the B-cell receptor in B cells. Mutations in the Btk PH domain result in changes in its affinity for PIP(3), with higher binding leading to cell transformation in vitro and lower binding leading to antibody deficiencies in both humans and mice. We describe here a fluorescence resonance energy transfer (FRET)-based biochemical assay that directly monitors the interaction of a PH domain with PIP(3) at a membrane surface. We overexpressed a fusion protein consisting of an enhanced green fluorescent protein (GFP) and the N-terminal 170 amino acids of a Tec family kinase that contains its PH domain (PH170). Homogeneous unilamellar vesicles were made that contained PIP(3) and octadecylrhodamine (OR), a lipophilic FRET acceptor for GFP. After optimization of both protein and vesicle components, we found that binding of the GFP-PH170 protein to PIP3 in vesicles that contain OR results in about a 90% reduction of GFP fluorescence. Using this assay to screen 1440 compounds, we identified three that efficiently inhibited binding of GFP-PH170 to PIP(3) in vesicles. This biochemical assay readily miniaturized to 1.8-microl reaction volumes and was validated in a 3456-well screening format.
Assuntos
Proteínas Sanguíneas/química , Membrana Celular/metabolismo , Avaliação Pré-Clínica de Medicamentos , Fosfatidilinositóis/metabolismo , Fosfoproteínas/química , Espectrometria de Fluorescência/métodos , Tirosina Quinase da Agamaglobulinemia , Animais , Ligação Competitiva , Relação Dose-Resposta a Droga , Glutationa Transferase/metabolismo , Proteínas de Fluorescência Verde , Humanos , Cinética , Metabolismo dos Lipídeos , Proteínas Luminescentes/metabolismo , Camundongos , Mutagênese Sítio-Dirigida , Ligação Proteica , Estrutura Terciária de Proteína , Proteínas Tirosina Quinases/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Fatores de TempoRESUMO
Protein phosphorylation is one of the major regulatory mechanisms involved in signal-induced cellular events, including cell proliferation, apoptosis, and metabolism. Because many facets of biology are regulated by protein phosphorylation, aberrant kinase and/or phosphatase activity forms the basis for many different types of pathology. The disease relevance of protein kinases and phosphatases has led many pharmaceutical and biotechnology companies to expend significant resources in lead discovery programs for these two target classes. The existence of >500 kinases and phosphatases encoded by the human genome necessitates development of methodologies for the rapid screening for novel and specific compound inhibitors. We describe here a fluorescence-based, molecular assay platform that is compatible with robotic, ultra-high throughput screening systems and can be applied to virtually all tyrosine and serine/threonine protein kinases and phosphatases. The assay has a coupled-enzyme format, utilizing the differential protease sensitivity of phosphorylated versus nonphosphorylated peptide substrates. In addition to screening individual kinases, the assay can be formatted such that kinase pathways are re-created in vitro to identify compounds that specifically interact with inactive kinases. Miniaturization of this assay format to the 1-microl scale allows for the rapid and accurate compound screening of a host of kinase and phosphatase targets, thereby facilitating the hunt for new leads for these target classes.
Assuntos
Bioensaio/instrumentação , Avaliação Pré-Clínica de Medicamentos/instrumentação , Biblioteca de Peptídeos , Fosfoproteínas Fosfatases/química , Proteínas Quinases/química , Sulfonamidas , Trifosfato de Adenosina/fisiologia , Animais , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Fluorescência , Humanos , Isoquinolinas/farmacologia , Toxinas Marinhas , Microcistinas , Peptídeos Cíclicos/farmacologia , Fosfoproteínas Fosfatases/antagonistas & inibidores , Inibidores de Proteínas Quinases , Proteínas Quinases/fisiologia , Transdução de Sinais/fisiologia , Estaurosporina/farmacologia , Vanadatos/farmacologiaRESUMO
Mammalian sterile 20-like kinase 1 (Mst1) is a MAPK kinase kinase kinase which is involved in a wide range of cellular responses, including apoptosis, lymphocyte adhesion and trafficking. The contribution of Mst1 to Ag-specific immune responses and autoimmunity has not been well defined. In this study, we provide evidence for the essential role of Mst1 in T cell differentiation and autoimmunity, using both genetic and pharmacologic approaches. Absence of Mst1 in mice reduced T cell proliferation and IL-2 production in vitro, blocked cell cycle progression, and elevated activation-induced cell death in Th1 cells. Mst1 deficiency led to a CD4+ T cell development path that was biased toward Th2 and immunoregulatory cytokine production with suppressed Th1 responses. In addition, Mst1-/- B cells showed decreased stimulation to B cell mitogens in vitro and deficient Ag-specific Ig production in vivo. Consistent with altered lymphocyte function, deletion of Mst1 reduced the severity of experimental autoimmune encephalomyelitis (EAE) and protected against collagen-induced arthritis development. Mst1-/- CD4+ T cells displayed an intrinsic defect in their ability to respond to encephalitogenic antigens and deletion of Mst1 in the CD4+ T cell compartment was sufficient to alleviate CNS inflammation during EAE. These findings have prompted the discovery of novel compounds that are potent inhibitors of Mst1 and exhibit desirable pharmacokinetic properties. In conclusion, this report implicates Mst1 as a critical regulator of adaptive immune responses, Th1/Th2-dependent cytokine production, and as a potential therapeutic target for immune disorders.
Assuntos
Autoimunidade , Fator de Crescimento de Hepatócito/genética , Proteínas Proto-Oncogênicas/genética , Linfócitos T/imunologia , Animais , Artrite Reumatoide/imunologia , Sequência de Bases , Primers do DNA , Ativação Linfocitária , Teste de Cultura Mista de Linfócitos , Camundongos , Camundongos Endogâmicos BALB C , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Protein tyrosine phosphatase-γ (PTP-γ) is a receptor-like PTP whose biological function is poorly understood. A recent mouse PTP-γ genetic deletion model associated the loss of PTP-γ gene expression with a potential antidepressant phenotype. This led the authors to screen a subset of the Bristol-Myers Squibb (BMS) compound collection to identify selective small-molecule inhibitors of receptor-like PTP-γ (RPTP-γ) for use in evaluating enzyme function in vivo. Here, they report the design of a high-throughput fluorescence resonance energy transfer (FRET) assay based on the Z'-LYTE technology to screen for inhibitors of RPTP-γ. A subset of the BMS diverse compound collection was screened and several compounds identified as RPTP-γ inhibitors in the assay. After chemical triage and clustering, compounds were assessed for potency and selectivity by IC(50) determination with RPTP-γ and two other phosphatases, PTP-1B and CD45. One hundred twenty-nine RPTP-γ selective (defined as IC(50) value greater than 5- to 10-fold over PTP-1B and CD45) inhibitors were identified and prioritized for evaluation. One of these hits, 3-(3, 4-dichlorobenzylthio) thiophene-2-carboxylic acid, was the primary chemotype for the initiation of a medicinal chemistry program.
Assuntos
Descoberta de Drogas/métodos , Inibidores Enzimáticos/metabolismo , Ensaios de Triagem em Larga Escala , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/antagonistas & inibidores , Dimetil Sulfóxido/farmacologia , Inibidores Enzimáticos/química , Estabilidade Enzimática/efeitos dos fármacos , Reprodutibilidade dos Testes , Projetos de Pesquisa , Sensibilidade e Especificidade , Solventes/farmacologiaRESUMO
The kinase suppressor of ras 2 (KSR2) gene resides at human chromosome 12q24, a region linked to obesity and type 2 diabetes (T2D). While knocking out and phenotypically screening mouse orthologs of thousands of druggable human genes, we found KSR2 knockout (KSR2(-/-)) mice to be more obese and glucose intolerant than melanocortin 4 receptor(-/-) (MC4R(-/-)) mice. The obesity and T2D of KSR2(-/-) mice resulted from hyperphagia which was unresponsive to leptin and did not originate downstream of MC4R. The kinases AMP-activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR) are each linked to food intake regulation, but only mTOR had increased activity in KSR2(-/-) mouse brain, and the ability of rapamycin to inhibit food intake in KSR2(-/-) mice further implicated mTOR in this process. The metabolic phenotype of KSR2 heterozygous (KSR2(+/minus;)) and KSR2(-/-) mice suggests that human KSR2 variants may contribute to a similar phenotype linked to human chromosome 12q24.
Assuntos
Tecido Adiposo/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Hiperfagia/metabolismo , Obesidade/metabolismo , Proteínas Quinases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Quinases Proteína-Quinases Ativadas por AMP , Animais , Ingestão de Alimentos/genética , Leptina/metabolismo , Camundongos , Camundongos Knockout , Proteínas Serina-Treonina Quinases/deficiência , Proteínas Serina-Treonina Quinases/genéticaRESUMO
The discovery of a pyrrolopyrimidine class of LIM-kinase 2 (LIMK2) inhibitors is reported. These LIMK2 inhibitors show good potency in enzymatic and cellular assays and good selectivity against ROCK. After topical dosing to the eye in a steroid induced mouse model of ocular hypertension, the compounds reduce intraocular pressure to baseline levels. The compounds also increase outflow facility in a pig eye perfusion assay. These results suggest LIMK2 may be an effective target for treating ocular hypertension and associated glaucoma.