RESUMEN
Obesity-associated insulin resistance plays a central role in type 2 diabetes. As such, tyrosine phosphatases that dephosphorylate the insulin receptor (IR) are potential therapeutic targets. The low-molecular-weight protein tyrosine phosphatase (LMPTP) is a proposed IR phosphatase, yet its role in insulin signaling in vivo has not been defined. Here we show that global and liver-specific LMPTP deletion protects mice from high-fat diet-induced diabetes without affecting body weight. To examine the role of the catalytic activity of LMPTP, we developed a small-molecule inhibitor with a novel uncompetitive mechanism, a unique binding site at the opening of the catalytic pocket, and an exquisite selectivity over other phosphatases. This inhibitor is orally bioavailable, and it increases liver IR phosphorylation in vivo and reverses high-fat diet-induced diabetes. Our findings suggest that LMPTP is a key promoter of insulin resistance and that LMPTP inhibitors would be beneficial for treating type 2 diabetes.
Asunto(s)
Diabetes Mellitus Tipo 2/tratamiento farmacológico , Inhibidores Enzimáticos/farmacología , Inhibidores Enzimáticos/uso terapéutico , Proteínas Tirosina Fosfatasas/antagonistas & inhibidores , Proteínas Tirosina Fosfatasas/genética , Bibliotecas de Moléculas Pequeñas , Animales , Sitios de Unión , Diabetes Mellitus Tipo 2/enzimología , Diabetes Mellitus Tipo 2/genética , Evaluación Preclínica de Medicamentos , Activación Enzimática/efectos de los fármacos , Eliminación de Gen , Concentración 50 Inhibidora , Ratones , Ratones Noqueados , Ratones Obesos , Modelos Biológicos , Estructura Molecular , Peso Molecular , Bibliotecas de Moléculas Pequeñas/farmacología , Relación Estructura-ActividadRESUMEN
Hepatic cystogenesis in polycystic liver disease is associated with increased levels of cyclic adenosine monophosphate (cAMP) in cholangiocytes lining liver cysts. Takeda G protein receptor 5 (TGR5), a G protein-coupled bile acid receptor, is linked to cAMP and expressed in cholangiocytes. Therefore, we hypothesized that TGR5 might contribute to disease progression. We examined expression of TGR5 and Gα proteins in cultured cholangiocytes and in livers of animal models and humans with polycystic liver disease. In vitro, we assessed cholangiocyte proliferation, cAMP levels, and cyst growth in response to (1) TGR5 agonists (taurolithocholic acid, oleanolic acid [OA], and two synthetic compounds), (2) a novel TGR5 antagonist (m-tolyl 5-chloro-2-[ethylsulfonyl] pyrimidine-4-carboxylate [SBI-115]), and (3) a combination of SBI-115 and pasireotide, a somatostatin receptor analogue. In vivo, we examined hepatic cystogenesis in OA-treated polycystic kidney rats and after genetic elimination of TGR5 in double mutant TGR5-/- ;Pkhd1del2/del2 mice. Compared to control, expression of TGR5 and Gαs (but not Gαi and Gαq ) proteins was increased 2-fold to 3-fold in cystic cholangiocytes in vitro and in vivo. In vitro, TGR5 stimulation enhanced cAMP production, cell proliferation, and cyst growth by â¼40%; these effects were abolished after TGR5 reduction by short hairpin RNA. OA increased cystogenesis in polycystic kidney rats by 35%; in contrast, hepatic cystic areas were decreased by 45% in TGR5-deficient TGR5-/- ;Pkhd1del2/del2 mice. TGR5 expression and its colocalization with Gαs were increased â¼2-fold upon OA treatment. Levels of cAMP, cell proliferation, and cyst growth in vitro were decreased by â¼30% in cystic cholangiocytes after treatment with SBI-115 alone and by â¼50% when SBI-115 was combined with pasireotide. CONCLUSION: TGR5 contributes to hepatic cystogenesis by increasing cAMP and enhancing cholangiocyte proliferation; our data suggest that a TGR5 antagonist alone or concurrently with somatostatin receptor agonists represents a potential therapeutic approach in polycystic liver disease. (Hepatology 2017;66:1197-1218).
Asunto(s)
AMP Cíclico/metabolismo , Quistes/metabolismo , Subunidades alfa de la Proteína de Unión al GTP Gs/metabolismo , Hepatopatías/metabolismo , Pirimidinas/uso terapéutico , Receptores Acoplados a Proteínas G/metabolismo , Proteínas Adaptadoras Transductoras de Señales , Animales , Proliferación Celular/efectos de los fármacos , Quistes/tratamiento farmacológico , Evaluación Preclínica de Medicamentos , Quimioterapia Combinada , Humanos , Hepatopatías/tratamiento farmacológico , Ratones , Ácido Oleanólico , Enfermedades Renales Poliquísticas/metabolismo , Cultivo Primario de Células , Pirimidinas/farmacología , Ratas , Receptores Acoplados a Proteínas G/agonistas , Receptores Acoplados a Proteínas G/antagonistas & inhibidores , Receptores Acoplados a Proteínas G/genética , Somatostatina/análogos & derivados , Somatostatina/farmacología , Somatostatina/uso terapéuticoRESUMEN
Alkaline phosphatase (AP) isozymes are present in a wide range of species from bacteria to man and are capable of dephosphorylation and transphosphorylation of a wide spectrum of substrates in vitro. In humans, four AP isozymes have been identified-one tissue-nonspecific (TNAP) and three tissue-specific-named according to the tissue of their predominant expression: intestinal (IAP), placental (PLAP) and germ cell (GCAP) APs. Modulation of activity of the different AP isozymes may have therapeutic implications in distinct diseases and cellular processes. For instance, changes in the level of IAP activity can affect gut mucosa tolerance to microbial invasion due to the ability of IAP to detoxify bacterial endotoxins, alter the absorption of fatty acids and affect ectopurinergic regulation of duodenal bicarbonate secretion. To identify isozyme selective modulators of the human and mouse IAPs, we developed a series of murine duodenal IAP (Akp3-encoded dIAP isozyme), human IAP (hIAP), PLAP, and TNAP assays. High throughput screening and subsequent SAR efforts generated a potent inhibitor of dIAP, ML260, with specificity for the Akp3-, compared to the Akp5- and Akp6-encoded mouse isozymes.
Asunto(s)
Acetanilidas/química , Acetanilidas/farmacología , Fosfatasa Alcalina/antagonistas & inhibidores , Sulfonamidas/química , Sulfonamidas/farmacología , Acetanilidas/aislamiento & purificación , Animales , Activación Enzimática/efectos de los fármacos , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/aislamiento & purificación , Inhibidores Enzimáticos/farmacología , Humanos , Ratones , Isoformas de Proteínas/química , Sulfonamidas/aislamiento & purificaciónRESUMEN
We recently reported the systematic ligand-based rational design and synthesis of monovalent Smac mimetics that bind preferentially to the BIR2 domain of the anti-apoptotic protein XIAP. Expanded structure-activity relationship (SAR) studies around these peptidomimetics led to compounds with significantly improved selectivity (>60-fold) for the BIR2 domain versus the BIR3 domain of XIAP. The potent and highly selective IAP antagonist 8q (ML183) sensitized TRAIL-resistant prostate cancer cells to apoptotic cell death, highlighting the merit of this probe compound as a valuable tool to investigate the biology of XIAP.
Asunto(s)
Materiales Biomiméticos/síntesis química , Diseño de Fármacos , Oligopéptidos/síntesis química , Proteína Inhibidora de la Apoptosis Ligada a X/antagonistas & inhibidores , Sitios de Unión , Materiales Biomiméticos/química , Materiales Biomiméticos/toxicidad , Línea Celular Tumoral , Supervivencia Celular , Resistencia a Antineoplásicos/efectos de los fármacos , Humanos , Simulación del Acoplamiento Molecular , Oligopéptidos/química , Oligopéptidos/toxicidad , Unión Proteica , Estructura Terciaria de Proteína , Relación Estructura-Actividad , Ligando Inductor de Apoptosis Relacionado con TNF/farmacología , Proteína Inhibidora de la Apoptosis Ligada a X/metabolismoRESUMEN
We report the systematic rational design and synthesis of new monovalent Smac mimetics that bind preferentially to the BIR2 domain of the anti-apoptotic protein XIAP. Characterization of compounds in vitro (including 9i; ML101) led to the determination of key structural requirements for BIR2 binding affinity. Compounds 9h and 9j sensitized TRAIL-resistant breast cancer cells to apoptotic cell death, highlighting the value of these probe compounds as tools to investigate the biology of XIAP.
Asunto(s)
Proteínas Reguladoras de la Apoptosis/química , Proteínas Mitocondriales/química , Proteína Inhibidora de la Apoptosis Ligada a X/antagonistas & inhibidores , Apoptosis , Sitios de Unión , Materiales Biomiméticos/síntesis química , Materiales Biomiméticos/química , Materiales Biomiméticos/farmacología , Línea Celular Tumoral , Simulación por Computador , Diseño de Fármacos , Humanos , Péptidos y Proteínas de Señalización Intracelular/química , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteínas Mitocondriales/metabolismo , Unión Proteica , Estructura Terciaria de Proteína , Ligando Inductor de Apoptosis Relacionado con TNF/farmacología , Proteína Inhibidora de la Apoptosis Ligada a X/química , Proteína Inhibidora de la Apoptosis Ligada a X/metabolismoRESUMEN
Obesity-associated insulin resistance plays a central role in the pathogenesis of type 2 diabetes. A promising approach to decrease insulin resistance in obesity is to inhibit the protein tyrosine phosphatases that negatively regulate insulin receptor signaling. The low-molecular-weight protein tyrosine phosphatase (LMPTP) acts as a critical promoter of insulin resistance in obesity by inhibiting phosphorylation of the liver insulin receptor activation motif. Here, we report development of a novel purine-based chemical series of LMPTP inhibitors. These compounds inhibit LMPTP with an uncompetitive mechanism and are highly selective for LMPTP over other protein tyrosine phosphatases. We also report the generation of a highly orally bioavailable purine-based analogue that reverses obesity-induced diabetes in mice.
Asunto(s)
Inhibidores Enzimáticos/química , Proteínas Tirosina Fosfatasas/antagonistas & inhibidores , Purinas/química , Administración Oral , Animales , Sitios de Unión , Cristalografía por Rayos X , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/etiología , Modelos Animales de Enfermedad , Evaluación Preclínica de Medicamentos , Inhibidores Enzimáticos/metabolismo , Inhibidores Enzimáticos/farmacología , Inhibidores Enzimáticos/uso terapéutico , Semivida , Humanos , Resistencia a la Insulina , Cinética , Simulación de Dinámica Molecular , Obesidad/complicaciones , Obesidad/patología , Fosforilación/efectos de los fármacos , Proteínas Tirosina Fosfatasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Purinas/metabolismo , Purinas/farmacología , Purinas/uso terapéutico , Transducción de Señal/efectos de los fármacos , Relación Estructura-ActividadRESUMEN
Invadopodia are actin-based proteolytic membrane protrusions required for invasive behavior and tumor growth. In this study, we used our high-content screening assay to identify kinases whose activity affects invadopodia formation. Among the top hits selected for further analysis was TAO3, an STE20-like kinase of the GCK subfamily. TAO3 was overexpressed in many human cancers and regulated invadopodia formation in melanoma, breast, and bladder cancers. Furthermore, TAO3 catalytic activity facilitated melanoma growth in three-dimensional matrices and in vivo. A novel, potent catalytic inhibitor of TAO3 was developed that inhibited invadopodia formation and function as well as tumor cell extravasation and growth. Treatment with this inhibitor demonstrated that TAO3 activity is required for endosomal trafficking of TKS5α, an obligate invadopodia scaffold protein. A phosphoproteomics screen for TAO3 substrates revealed the dynein subunit protein LIC2 as a relevant substrate. Knockdown of LIC2 or expression of a phosphomimetic form promoted invadopodia formation. Thus, TAO3 is a new therapeutic target with a distinct mechanism of action. SIGNIFICANCE: An unbiased screening approach identifies TAO3 as a regulator of invadopodia formation and function, supporting clinical development of this class of target.
Asunto(s)
Proteínas Adaptadoras del Transporte Vesicular/metabolismo , Endosomas/metabolismo , Invasividad Neoplásica/patología , Podosomas/efectos de los fármacos , Proteínas Serina-Treonina Quinasas/metabolismo , Animales , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Línea Celular Tumoral , Dineínas Citoplasmáticas/genética , Dineínas Citoplasmáticas/metabolismo , Conjuntos de Datos como Asunto , Matriz Extracelular , Femenino , Perfilación de la Expresión Génica , Técnicas de Silenciamiento del Gen , Ensayos Analíticos de Alto Rendimiento , Humanos , Masculino , Melanoma/tratamiento farmacológico , Melanoma/patología , Ratones , Invasividad Neoplásica/prevención & control , Podosomas/patología , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Neoplasias Cutáneas/tratamiento farmacológico , Neoplasias Cutáneas/patología , Imagen de Lapso de Tiempo , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Neurotensin receptor 1 (NTR1) is a G protein coupled receptor that is widely expressed throughout the central nervous system where it acts as a neuromodulator. Neurotensin receptors have been implicated in a wide variety of CNS disorders, but despite extensive efforts to develop small molecule ligands there are few reports of such compounds. Herein we describe the optimization of a quinazoline based lead to give 18 (SBI-553), a potent and brain penetrant NTR1 allosteric modulator.
Asunto(s)
Enfermedades del Sistema Nervioso Central/tratamiento farmacológico , Descubrimiento de Drogas , Quinazolinas/farmacología , Receptores de Neurotensina/antagonistas & inhibidores , beta-Arrestinas/farmacología , Administración Oral , Regulación Alostérica/efectos de los fármacos , Animales , Disponibilidad Biológica , Enfermedades del Sistema Nervioso Central/metabolismo , Proteínas de Transporte de Dopamina a través de la Membrana Plasmática/deficiencia , Proteínas de Transporte de Dopamina a través de la Membrana Plasmática/metabolismo , Relación Dosis-Respuesta a Droga , Femenino , Locomoción/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Estructura Molecular , Quinazolinas/administración & dosificación , Quinazolinas/química , Ratas , Receptores de Neurotensina/metabolismo , Relación Estructura-Actividad , beta-Arrestinas/administración & dosificación , beta-Arrestinas/químicaRESUMEN
Treatment of inflammation is often accomplished through the use of glucocorticoids. However, their use is limited by side effects. We have examined the activity of a novel glucocorticoid receptor ligand that binds the receptor efficiently and strongly represses inflammatory gene expression. This compound has potent antiinflammatory activity in vivo and represses the transcription of the inflammatory cytokine monocyte chemoattractant protein-1 and induces the antiinflammatory cytokine IL-10. The compound demonstrates differential gene regulation, compared with commonly prescribed glucocorticoids, effectively inducing some genes and repressing others in a manner different from the glucocorticoid prednisolone. The separation between the antiinflammatory effects of LGD-5552 and the side effects commonly associated with glucocorticoid treatment suggest that this molecule differs significantly from prednisolone and other steroids and may provide a safer therapeutic window for inflammatory conditions now commonly treated with steroidal glucocorticoids.
Asunto(s)
Antiinflamatorios/efectos adversos , Antiinflamatorios/uso terapéutico , Artritis Experimental/tratamiento farmacológico , Benzopiranos/efectos adversos , Benzopiranos/uso terapéutico , Compuestos de Bencilideno/efectos adversos , Compuestos de Bencilideno/uso terapéutico , Receptores de Glucocorticoides/agonistas , Animales , Artritis Reumatoide/tratamiento farmacológico , Células Cultivadas , Evaluación Preclínica de Medicamentos , Humanos , Ligandos , Masculino , Modelos Biológicos , Prednisolona/efectos adversos , Prednisolona/uso terapéutico , Ratas , Ratas Endogámicas Lew , Ratas Endogámicas WKY , Ratas Sprague-Dawley , Spodoptera , Especificidad por SustratoRESUMEN
Specific retinoid X receptor (RXR) agonists, such as LG100268 (LG268), and the thiazolidinedione (TZD) PPARgamma agonists, such as rosiglitazone, produce insulin sensitization in rodent models of insulin resistance and type 2 diabetes. In sharp contrast to the TZDs that produce significant increases in body weight gain, RXR agonists reduce body weight gain and food consumption. Unfortunately, RXR agonists also suppress the thyroid hormone axis and generally produce hypertriglyceridemia. Heterodimer-selective RXR modulators have been identified that, in rodents, retain the metabolic benefits of RXR agonists with reduced side effects. These modulators bind specifically to RXR with high affinity and are RXR homodimer partial agonists. Although RXR agonists activate many heterodimer partners, these modulators selectively activate RXR:PPARalpha and RXR:PPARgamma, but not RXR:RARalpha, RXR:LXRalpha, RXR:LXRbeta, or RXR:FXRalpha. We report the in vivo characterization of one RXR modulator, LG101506 (LG1506). In Zucker fatty (fa/fa) rats, LG1506 is a potent insulin sensitizer that also enhances the insulin-sensitizing activities of rosiglitazone. Administration of LG1506 reduces both body weight gain and food consumption and blocks the TZD-induced weight gain when coadministered with rosiglitazone. LG1506 does not significantly suppress the thyroid hormone axis in rats, nor does it elevate triglycerides in Sprague Dawley rats. However, LG1506 produces a unique pattern of triglycerides elevation in Zucker rats. LG1506 elevates high-density lipoprotein cholesterol in humanized apolipoprotein A-1-transgenic mice. Therefore, selective RXR modulators are a promising approach for developing improved therapies for type 2 diabetes, although additional studies are needed to understand the strain-specific effects on triglycerides.
Asunto(s)
Diabetes Mellitus Tipo 2/tratamiento farmacológico , Ácidos Grasos Insaturados/administración & dosificación , Hipoglucemiantes/administración & dosificación , Obesidad/tratamiento farmacológico , Éteres Fenílicos/administración & dosificación , Receptores X Retinoide/agonistas , Tiazolidinedionas/administración & dosificación , Análisis de Varianza , Animales , Apolipoproteína A-I/genética , Apolipoproteína A-I/fisiología , Área Bajo la Curva , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/complicaciones , Relación Dosis-Respuesta a Droga , Interacciones Farmacológicas , Femenino , Hipoglucemiantes/uso terapéutico , Ratones , Ratones Transgénicos , Obesidad/sangre , Obesidad/complicaciones , PPAR gamma/agonistas , PPAR gamma/metabolismo , Ratas , Ratas Sprague-Dawley , Ratas Zucker , Receptores X Retinoide/metabolismo , Rosiglitazona , Estadísticas no Paramétricas , Tiazolidinedionas/farmacología , Tiazolidinedionas/uso terapéutico , Glándula Tiroides/efectos de los fármacos , Triglicéridos/sangreRESUMEN
Members of the Inhibitor of APoptosis (IAP) protein family suppress apoptosis within tumor cells, particularly in the context of immune cell-mediated killing by the tumor necrosis factor (TNF) superfamily cytokines. Most IAPs are opposed endogenously by the second mitochondrial activator of caspases (SMAC), which binds to selected baculovirus IAP repeat (BIR) domains of IAPs to displace interacting proteins. The development of SMAC mimetics as novel anticancer drugs has gained impetus, with several agents now in human clinical trials. To further understand the cellular mechanisms of SMAC mimetics, we focused on IAP family members cIAP1 and cIAP2, which are recruited to TNF receptor complexes where they support cell survival through NF-κB activation while suppressing apoptosis by preventing caspase activation. We established fluorescence polarization (FP) assays for the BIR2 and BIR3 domains of human cIAP1 and cIAP2 using fluorochrome-conjugated SMAC peptides as ligands. A library of SMAC mimetics was profiled using the FP assays to provide a unique structure activity relationship (SAR) analysis compared to previous assessments of binding to XIAP. Potent compounds displayed mean inhibitory binding constants (Ki) of 9 to 27 nM against the BIR3 domains of cIAP1 and cIAP2, respectively. Selected compounds were then characterized using cytotoxicity assays in which a cytokine-resistant human tumor cell line was sensitized to either TNF or lymphotoxin-α (LT-α). Cytotoxicity correlated closely with cIAP1 and cIAP2 BIR3 binding activity with the most potent compounds able to reduce cell viability by 50%. Further testing demonstrated that active compounds also inhibit RIP1 binding to BIR3 of cIAP1 and cIAP2 in vitro and reduce steady-state cIAP1 protein levels in cells. Altogether, these data inform the SAR for our SMAC mimetics with respect to cIAP1 and cIAP2, suggesting that these IAP family members play an important role in tumor cell resistance to cytotoxicity mediated by TNF and LT-α.
Asunto(s)
Apoptosis/fisiología , Proteínas Inhibidoras de la Apoptosis/fisiología , Péptidos y Proteínas de Señalización Intracelular/fisiología , Proteínas Mitocondriales/fisiología , Imitación Molecular , Factor de Necrosis Tumoral alfa/fisiología , Proteínas Reguladoras de la Apoptosis , Línea Celular Tumoral , Polarización de Fluorescencia , Humanos , Proteínas Inhibidoras de la Apoptosis/metabolismo , Péptidos y Proteínas de Señalización Intracelular/química , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteínas Mitocondriales/química , Proteínas Mitocondriales/metabolismo , Unión ProteicaRESUMEN
A novel nonthiazolidinedione dual peroxisome proliferator- activated receptor (PPAR)-alpha/gamma agonist, LY465608, was designed to address the major metabolic disturbances of type 2 diabetes. LY465608 altered PPAR-responsive genes in liver and fat of db/db mice and dose-dependently lowered plasma glucose in hyperglycemic male Zucker diabetic fatty (ZDF) rats, with an ED(50) for glucose normalization of 3.8 mg small middle dot kg(-1) small middle dot day(-1). Metabolic improvements were associated with enhanced insulin sensitivity, as demonstrated in female obese Zucker (fa/fa) rats using both oral glucose tolerance tests and hyperinsulinemic-euglycemic clamps. Further characterization of LY465608 revealed metabolic changes distinct from a selective PPAR-gamma agonist, which were presumably due to the concomitant PPAR-alpha agonism, lower respiratory quotient, and less fat accumulation, despite a similar impact on glycemia in male ZDF rats. In addition to these alterations in diabetic and insulin-resistant animals, LY465608 dose-dependently elevated HDL cholesterol and lowered plasma triglycerides in human apolipoprotein A-I transgenic mice, demonstrating that this compound significantly improves primary cardiovascular risk factors. Overall, these studies demonstrate that LY465608 beneficially impacts multiple facets of type 2 diabetes and associated cardiovascular risk, including those facets involved in the development of micro- and macrovascular complications, which are the major sources for morbidity and mortality in these patients.
Asunto(s)
Glucemia/metabolismo , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Hiperglucemia/tratamiento farmacológico , Hipoglucemiantes/uso terapéutico , Resistencia a la Insulina , Síndrome Metabólico/fisiología , Compuestos Orgánicos , Receptores Citoplasmáticos y Nucleares/agonistas , Tiazolidinedionas , Factores de Transcripción/agonistas , Animales , Glucemia/efectos de los fármacos , Proteínas de Unión al ADN/agonistas , Diabetes Mellitus Tipo 2/sangre , Relación Dosis-Respuesta a Droga , Ingestión de Energía/efectos de los fármacos , Metabolismo Energético/efectos de los fármacos , Prueba de Tolerancia a la Glucosa , Masculino , Ratones , Ratones Mutantes , Ratas , Ratas Zucker , Rosiglitazona , Tiazoles/uso terapéuticoRESUMEN
Retinoid X receptor:peroxisome proliferative-activated receptor (RXR:PPAR) heterodimers play a critical role in the regulation of glucose (RXR/PPARgamma) and lipid metabolism (RXR/PPARalpha). Previously, we described a concise structure-activity relationship study of selective RXR modulators possessing a (2E,4E,6Z)-3-methyl-7-(3,5-dialkyl-6-alkoxyphenyl)-octa-2,4,6-trienoic acid scaffold. These studies were focused on the 2-position alkoxy side chain. We describe here the design and synthesis of a novel series of RXR selective modulators possessing the same aromatic core structure with the addition of a ring locked 6-7-Z-olefin on the trienoic acid moiety. The synthesis and structure-activity relationship studies of these 6,7-locked cyclopentenyl, phenyl, thienyl, furan, and pyridine-trienoic acid derivatives is presented herein.
Asunto(s)
Derivados del Benceno/química , Derivados del Benceno/farmacología , Caprilatos/química , Caprilatos/farmacología , Tiazolidinedionas , Alquenos/química , Alquenos/farmacología , Animales , Derivados del Benceno/síntesis química , Caprilatos/síntesis química , Línea Celular , Chlorocebus aethiops , Relación Dosis-Respuesta a Droga , Diseño de Fármacos , Sinergismo Farmacológico , Hipoglucemiantes/química , Hipoglucemiantes/farmacología , Masculino , Ratones , Ensayo de Unión Radioligante , Ratas , Ratas Sprague-Dawley , Receptores de Ácido Retinoico/agonistas , Receptores de Ácido Retinoico/antagonistas & inhibidores , Receptores de Ácido Retinoico/genética , Receptores de Ácido Retinoico/metabolismo , Receptores X Retinoide , Rosiglitazona , Relación Estructura-Actividad , Tiazoles/farmacología , Tiroxina/sangre , Factores de Transcripción/agonistas , Factores de Transcripción/antagonistas & inhibidores , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Transfección , Triglicéridos/sangreRESUMEN
The design and synthesis of the dual peroxisome proliferator activated receptor (PPAR) alpha/gamma agonist (S)-2-methyl-3-[4-[2-(5-methyl-2-thiophen-2-yl-oxazol-4-yl)ethoxy]phenyl]-2-phenoxypropionic acid (2) for the treatment of type 2 diabetes and associated dyslipidemia are described. 2 possesses a potent dual hPPAR alpha/gamma agonist profile (IC(50) = 28 and 10 nM; EC(50) = 9 and 4 nM, respectively, for hPPARalpha and hPPARgamma). In preclinical models, 2 substantially improves insulin sensitivity and potently reverses diabetic hyperglycemia while significantly improving overall lipid homeostasis.
Asunto(s)
Hipoglucemiantes/síntesis química , Hipolipemiantes/síntesis química , Fenilpropionatos/síntesis química , Receptores Citoplasmáticos y Nucleares/agonistas , Tiofenos/síntesis química , Factores de Transcripción/agonistas , Animales , Unión Competitiva , Línea Celular , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Femenino , Humanos , Hiperlipidemias/tratamiento farmacológico , Hipoglucemiantes/química , Hipoglucemiantes/farmacología , Hipolipemiantes/química , Hipolipemiantes/farmacología , Fenilpropionatos/química , Fenilpropionatos/farmacología , Ensayo de Unión Radioligante , Ratas , Ratas Zucker , Estereoisomerismo , Relación Estructura-Actividad , Tiofenos/química , Tiofenos/farmacologíaRESUMEN
TNF-related apoptosis-inducing ligand (TRAIL) is a promising anticancer agent because it shows apoptosis-inducing activity in transformed, but not in normal, cells. As with most anticancer agents, however, its clinical use is restricted by either inherent or acquired resistance by cancer cells. We demonstrate here that small-molecule SMAC mimetics that antagonize the inhibitor of apoptosis proteins (IAP) potently sensitize previously resistant human cancer cell lines, but not normal cells, to TRAIL-induced apoptosis, and that they do so in a caspase-8-dependent manner. We further show that the compounds have no cytotoxicity as single agents. Also, we demonstrate that several IAP family members likely participate in the modulation of cellular sensitivity to TRAIL. Finally, we note that the compounds that sensitize cancer cells to TRAIL are the most efficacious in binding to X-linked IAP, and in inducing cellular-IAP (cIAP)-1 and cIAP-2 degradation. Our studies thus describe valuable compounds that allow elucidation of the signaling events occurring in TRAIL resistance, and demonstrate that these agents act as potent TRAIL-sensitizing agents in a variety of cancer cell lines.
Asunto(s)
Proteínas Inhibidoras de la Apoptosis/metabolismo , Neoplasias/genética , Ligando Inductor de Apoptosis Relacionado con TNF/genética , Proteína Inhibidora de la Apoptosis Ligada a X/metabolismo , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Proteína 3 que Contiene Repeticiones IAP de Baculovirus , Caspasa 8/genética , Caspasa 8/metabolismo , Línea Celular Tumoral , Resistencia a Antineoplásicos/efectos de los fármacos , Resistencia a Antineoplásicos/genética , Humanos , Proteínas Inhibidoras de la Apoptosis/antagonistas & inhibidores , Terapia Molecular Dirigida , Neoplasias/tratamiento farmacológico , Neoplasias/patología , Transducción de Señal/efectos de los fármacos , Bibliotecas de Moléculas Pequeñas/administración & dosificación , Ligando Inductor de Apoptosis Relacionado con TNF/administración & dosificación , Ubiquitina-Proteína Ligasas , Proteína Inhibidora de la Apoptosis Ligada a X/antagonistas & inhibidoresRESUMEN
A series of novel, potent antagonists of the inhibitor of apoptosis proteins (IAPs) were synthesized in a highly convergent and rapid fashion (≤6 steps) using the Ugi four-component reaction as the key step, thus enabling rapid optimization of binding potency. These IAP antagonists compete with caspases 3, 7, and 9 for inhibition by X chromosome-linked IAP (XIAP) and bind strongly (nanomolar binding constants) to several crucial members of the IAP family of cancer pro-survival proteins to promote apoptosis, with a particularly unique selectivity for melanoma IAP (ML-IAP). Experiments in cell culture revealed powerful cancer cell growth inhibitory activity in multiple (breast, ovarian, and prostate) cell lines with single agent toxicity at low nanomolar levels against SKOV-3 human ovarian carcinoma cells. Administration of the compounds to human foreskin fibroblast cells revealed no general toxicity to normal cells. Furthermore, computational modeling was performed, revealing key contacts between the IAP proteins and antagonists, suggesting a structural basis for the observed potency.
Asunto(s)
Proteínas Inhibidoras de la Apoptosis/antagonistas & inhibidores , Melanoma/metabolismo , Inhibidores de Caspasas/farmacología , Diseño de Fármacos , Polarización de Fluorescencia , Proteínas Inhibidoras de la Apoptosis/metabolismo , Modelos MolecularesRESUMEN
A series of 5-benzylidene-1,2-dihydro-2,2,4-trimethyl-5H-1-aza-6-oxa-chrysenes was synthesized and profiled for their ability to act as selective glucocorticoid receptor modulators (SGRMs). The synthesis and structure-activity relationships for this series of compounds are presented.
Asunto(s)
Crisenos/farmacología , Receptores de Glucocorticoides/efectos de los fármacos , Crisenos/síntesis química , Crisenos/química , Relación Estructura-ActividadRESUMEN
Biological effects of retinoids are mediated via retinoic acid (RA) receptors (RAR) and retinoid X receptors (RXR). The best-characterized mechanism of retinoid action is stimulation of transcription from promoters containing RA response elements (RARE). Retinoids induce senescence-like growth arrest in MCF-7 breast carcinoma cells; this effect is associated with the induction of several growth-inhibitory genes. We have now found that these genes are induced by RAR-specific but not by RXR-specific ligands. Genome-scale microarray analysis of gene expression was used to compare the effects of two pan-RAR ligands, one of which is a strong agonist of RARE-dependent transcription, whereas the other induces such transcription only weakly and antagonizes the inducing effect of RAR agonists. Both RAR ligands, however, produced very similar effects on gene expression in MCF-7 cells, suggesting that RARE-dependent transcription is only a minor component of retinoid-induced changes in gene expression. The effects of RAR ligands on gene expression parallel changes associated with damage-induced senescence, and both ligands induced G(1) arrest and the senescent phenotype in MCF-7 cells. The RAR ligands up-regulated many tumor-suppressive genes and down-regulated multiple genes with oncogenic activities. Genes that are strongly induced by RAR ligands encode secreted bioactive proteins, including several tumor-suppressing factors. In agreement with these observations, retinoid-treated MCF-7 cells inhibited the growth of retinoid-insensitive MDA-MB-231 breast carcinoma cells in coculture. These results indicate that RARE-independent transcriptional effects of RAR ligands lead to senescence-like growth arrest and paracrine growth-inhibitory activity in MCF-7 breast carcinoma cells.
Asunto(s)
Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Ácidos Grasos Insaturados/farmacología , Receptores de Ácido Retinoico/agonistas , Retinoides/farmacología , Actinas/genética , Antineoplásicos/farmacología , Neoplasias de la Mama/tratamiento farmacológico , División Celular/efectos de los fármacos , Línea Celular Tumoral , Senescencia Celular/efectos de los fármacos , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Análisis de Secuencia por Matrices de Oligonucleótidos , Receptores de Ácido Retinoico/antagonistas & inhibidores , Relación Estructura-ActividadRESUMEN
New RXR-selective modulators possessing a 6-fluoro trienoic acid moiety (6Z olefin) or a fluorinated/heterocyclic-substituted benzene core ring, were synthesized in an expedient and selective way. A subset of these compounds was evaluated for their metabolic properties (exposure in IRC male mice) and show a dramatic increase of exposure compared to our reference compound, 3 (LG101506).
Asunto(s)
Cumarinas/síntesis química , Cumarinas/farmacología , Receptores de Ácido Retinoico/fisiología , Factores de Transcripción/fisiología , Animales , Unión Competitiva , Línea Celular , Diseño de Fármacos , Cinética , Masculino , Ratones , Receptores de Ácido Retinoico/efectos de los fármacos , Receptor alfa de Ácido Retinoico , Receptores X Retinoide , Factores de Transcripción/efectos de los fármacos , Tretinoina/farmacocinética , Receptor de Ácido Retinoico gammaRESUMEN
To understand the species selectivity in a series of alpha-methyl-alpha-phenoxy carboxylic acid PPARalpha/gamma dual agonists (1-11), structure-based molecular modeling was carried out in the ligand binding pockets of both human and mouse PPARalpha. This study suggested that interaction of both 4-phenoxy and phenyloxazole substituents of these ligands with F272 and M279 in mouse PPARalpha leads to the species-specific divergence in ligand binding. Insights obtained in the molecular modeling studies of these key interactions resulted in the ability to convert a human-selective PPARalpha agonist to a human and mouse dual agonist within the same platform.