RESUMEN
Amyotrophic lateral sclerosis (ALS) is a progressive neurological disorder with currently no cure. Central to the cellular dysfunction associated with this fatal proteinopathy is the accumulation of unfolded/misfolded superoxide dismutase 1 (SOD1) in various subcellular locations. The molecular mechanism driving the formation of SOD1 aggregates is not fully understood but numerous studies suggest that aberrant aggregation escalates with folding instability of mutant apoSOD1. Recent advances on combining organelle-targeting therapies with the anti-aggregation capacity of chemical chaperones have successfully reduce the subcellular load of misfolded/aggregated SOD1 as well as their downstream anomalous cellular processes at low concentrations (micromolar range). Nevertheless, if such local aggregate reduction directly correlates with increased folding stability remains to be explored. To fill this gap, we synthesized and tested here the effect of 9 ER-, mitochondria- and lysosome-targeted chemical chaperones on the folding stability of truncated monomeric SOD1 (SOD1bar) mutants directed to those organelles. We found that compound ER-15 specifically increased the native state stability of ER-SOD1bar-A4V, while scaffold compound FDA-approved 4-phenylbutyric acid (PBA) decreased it. Furthermore, our results suggested that ER15 mechanism of action is distinct from that of PBA, opening new therapeutic perspectives of this novel chemical chaperone on ALS treatment.
Asunto(s)
Esclerosis Amiotrófica Lateral , Humanos , Superóxido Dismutasa-1/genética , Superóxido Dismutasa-1/química , Superóxido Dismutasa-1/metabolismo , Esclerosis Amiotrófica Lateral/tratamiento farmacológico , Pliegue de Proteína , Mutación , Chaperonas MolecularesRESUMEN
Since the 1950's, AMP-kinase (AMPK) has been used as a promising target for the development of antidiabetic drugs against Type 2 diabetes mellitus (T2D). Indeed, the canonical antidiabetic drug metformin recruits, at least partially, AMPK activation for its therapeutic effect. Herein we present design and synthesis of 20 novel relatively polar cyclic and acyclic dithioacetals of 2-(Het)arylchroman-6-carbaldehydes, 2-phenyl-1,4-benzodioxane-6-carbaldehyde, and 2-phenylbenzofuran-5-carbaldehyde, which were developed as potential AMPK activators. Three of the synthesized dithioacetals demonstrated significant enhancement (≥70%) of glucose uptake in rat L6 myotubes. Noteworthy, one of the dithioacetals, namely 4-(6-(1,3-dithian-2-yl)chroman-2-yl)pyridine, exhibited high potency comparing to other molecules. It increased the rate of glucose uptake in rat L6 myotubes and augmented insulin secretion from rat INS-1E cells in pharmacological relevant concentrations (up to 2 µM). Both effects were mediated by activation of AMPK. In addition, the compound showed excellent pharmacokinetic profile in healthy mice, including maximal oral bioavailability. Such bifunctionality (increased glucose uptake and insulin secretion) can be used as a starting point for the development of a novel class of antidiabetic drugs with dual activity that is relevant for T2D treatment.
Asunto(s)
Diabetes Mellitus Tipo 2 , Hipoglucemiantes , Ratas , Ratones , Animales , Hipoglucemiantes/farmacología , Hipoglucemiantes/uso terapéutico , Proteínas Quinasas Activadas por AMP , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Glucosa/farmacología , Línea Celular , Fibras Musculares Esqueléticas , Insulina/farmacologíaRESUMEN
IFN-ß is a cytokine that plays a significant role in the immune system. Inhibition of IFN-ß might be used as a therapeutic approach to treat septic shock. A peptidomimetic previously developed by our research team, 1-benzyl-5-methyl-4-(n-octylamino)pyrimidin-2(1H)-one (LT87), was used as an cardioprotective agent in a myocardial ischemia (MI) mouse model. We have developed new LT87 derivatives by synthetizing its dimers in an attempt to extend its structural variety and enhance its biological activity. A dimeric derivative, LT127, exhibited a dose-dependent inhibition of LPS-mediated IFN-ß and subsequent CXCL10 mRNA transcription. The effect was selective and transduced through TLR4- and TRAM/TRIF-mediated signaling, with no significant effect on MyD88-dependent signaling. However, this effect was not specific to TLR4, since a similar effect was observed both on TLR8- and MDA5/RIG-I-stimulated IFN-ß expression. Nevertheless, LT127 might serve as a drug candidate, specifically as an inhibitor for IFN-ß production in order to develop a novel therapeutic approach to prevent septic shock.
Asunto(s)
Interferón beta , Peptidomiméticos , Choque Séptico , Animales , Citocinas/metabolismo , Interferón beta/metabolismo , Ratones , Peptidomiméticos/farmacología , Choque Séptico/tratamiento farmacológico , Transducción de Señal , Receptor Toll-Like 4/genética , Receptor Toll-Like 4/metabolismoRESUMEN
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the degeneration of motor neurons. Mutations in the superoxide dismutase (SOD1) gene, causing protein misfolding and aggregation, were suggested as the pathogenic mechanisms involved in familial ALS cases. In the present study, we investigated the potential therapeutic effect of C4 and C5, two derivatives of the chemical chaperone 4-phenylbutyric acid (4-PBA). By combining in vivo and in vitro techniques, we show that, although C4 and C5 successfully inhibited amyloid aggregation of recombinant mutant SOD1 in a dose-dependent manner, they failed to suppress the accumulation of misfolded SOD1. Moreover, C4 or C5 daily injections to SOD1G93A mice following onset had no effect on either the accumulation of misfolded SOD1 or the neuroinflammatory response in the spinal cord and, consequently, failed to extend the survival of SOD1G93A mice or to improve their motor symptoms. Finally, pharmacokinetic (PK) studies demonstrated that high concentrations of C4 and C5 reached the brain and spinal cord but only for a short period of time. Thus, our findings suggest that use of such chemical chaperones for ALS drug development may need to be optimized for more effective results.
Asunto(s)
Esclerosis Amiotrófica Lateral , Enfermedades Neurodegenerativas , Amiloide/metabolismo , Proteínas Amiloidogénicas/metabolismo , Esclerosis Amiotrófica Lateral/tratamiento farmacológico , Esclerosis Amiotrófica Lateral/genética , Esclerosis Amiotrófica Lateral/metabolismo , Animales , Butilaminas , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Ratones , Ratones Transgénicos , Chaperonas Moleculares/metabolismo , Chaperonas Moleculares/farmacología , Enfermedades Neurodegenerativas/metabolismo , Fenilbutiratos , Médula Espinal/metabolismo , Superóxido Dismutasa/metabolismo , Superóxido Dismutasa-1/metabolismoRESUMEN
The C2-WW-HECT-domain E3 ubiquitin ligase SMURF2 emerges as an important regulator of diverse cellular processes. To date, SMURF2-specific modulators were not developed. Here, we generated and investigated a set of SMURF2-targeting synthetic peptides and peptidomimetics designed to stimulate SMURF2's autoubiquitination and turnover via a disruption of the inhibitory intramolecular interaction between its C2 and HECT domains. The results revealed the effects of these molecules both in vitro and in cellulo at the nanomolar concentration range. Moreover, the data showed that targeting of SMURF2 with either these modifiers or SMURF2-specific shRNAs could accelerate cell growth in a cell-context-dependent manner. Intriguingly, a concomitant cell treatment with a selected SMURF2-targeting compound and the DNA-damaging drug etoposide markedly increased the cytotoxicity produced by this drug in growing cells. Altogether, these findings demonstrate that SMURF2 can be druggable through its self-destructive autoubiquitination, and inactivation of SMURF2 might be used to affect cell sensitivity to certain anticancer drugs.
Asunto(s)
Antineoplásicos/farmacología , Desarrollo de Medicamentos , Inhibidores Enzimáticos/farmacología , Ubiquitina-Proteína Ligasas/antagonistas & inhibidores , Antineoplásicos/síntesis química , Antineoplásicos/química , Línea Celular , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/química , Humanos , Estructura Molecular , Relación Estructura-Actividad , Ubiquitina-Proteína Ligasas/metabolismoRESUMEN
Free fatty acids are essential structural components of the cell, and their intracellular distribution and effects on membrane organelles have crucial roles in regulating the metabolism, development, and cell cycle of most cell types. Here we engineered novel fluorescent, polarity-sensitive fatty acid derivatives, with the fatty acid aliphatic chain of increasing length (from 12 to 18 carbons). As in the laurdan probe, the lipophilic acyl tail is connected to the environmentally sensitive dimethylaminonaphthalene moiety. The fluorescence lifetime imaging analysis allowed us to monitor the intracellular distribution of the free fatty acids within the cell, and to simultaneously examine how the fluidity and the microviscosity of the membrane environment influence their localization. Each of these probes can thus be used to investigate the membrane fluidity regulation of the correspondent fatty acid intracellular distribution. We observed that, in PC-12 cells, fluorescent sensitive fatty acid derivatives with increased chain length compartmentalize more preferentially in the fluid regions, characterized by a low microviscosity. Moreover, fatty acid derivatives with the longest chain compartmentalize in lipid droplets and lysosomes with characteristic lifetimes, thus making these probes a promising tool for monitoring lipophagy and related events.
Asunto(s)
Ácidos Grasos/metabolismo , Colorantes Fluorescentes/metabolismo , Espacio Intracelular/metabolismo , Fluidez de la Membrana , 2-Naftilamina/análogos & derivados , 2-Naftilamina/química , Animales , Fluorescencia , Lauratos/química , Lisosomas/metabolismo , Células PC12 , Ratas , Solventes , ViscosidadRESUMEN
We recently developed a molecule (GT-73) that blocked leukocyte transendothelial migration from blood to the peripheral tissues, supposedly by affecting the platelet endothelial cell adhesion molecule (PECAM-1) function. GT-73 was tested in an LPS-induced acute respiratory distress syndrome (ARDS) mouse model. The rationale for this is based on the finding that the mortality of COVID-19 patients is partly caused by ARDS induced by a massive migration of leukocytes to the lungs. In addition, the role of tert-butyl and methyl ester moieties in the biological effect of GT-73 was investigated. A human leukocyte, transendothelial migration assay was applied to validate the blocking effect of GT-73 derivatives. Finally, a mouse model of LPS-induced ARDS was used to evaluate the histological and biochemical effects of GT-73. The obtained results showed that GT-73 has a unique structure that is responsible for its biological activity; two of its chemical moieties (tert-butyl and a methyl ester) are critical for this effect. GT-73 is a prodrug, and its lipophilic tail covalently binds to PECAM-1 via Lys536. GT-73 significantly decreased the number of infiltrating leukocytes in the lungs and reduced the inflammation level. Finally, GT-73 reduced the levels of IL-1ß, IL-6, and MCP-1 in bronchoalveolar lavage fluid (BALF). In summary, we concluded that GT-73, a blocker of white blood cell transendothelial migration, has a favorable profile as a drug candidate for the treatment of ARDS in COVID-19 patients.
Asunto(s)
Tratamiento Farmacológico de COVID-19 , Leucocitos/efectos de los fármacos , Molécula-1 de Adhesión Celular Endotelial de Plaqueta/antagonistas & inhibidores , Pirimidinas/farmacología , Síndrome de Dificultad Respiratoria/tratamiento farmacológico , Migración Transendotelial y Transepitelial/efectos de los fármacos , Animales , COVID-19/patología , Adhesión Celular/efectos de los fármacos , Adhesión Celular/inmunología , Movimiento Celular/efectos de los fármacos , Síndrome de Liberación de Citoquinas/tratamiento farmacológico , Citocinas/metabolismo , Modelos Animales de Enfermedad , Femenino , Humanos , Leucocitos/inmunología , Lipopolisacáridos/efectos adversos , Ratones , Ratones Endogámicos BALB C , Molécula-1 de Adhesión Celular Endotelial de Plaqueta/inmunología , Pirimidinas/química , Síndrome de Dificultad Respiratoria/inducido químicamente , SARS-CoV-2RESUMEN
Chemical chaperones prevent protein aggregation. However, the use of chemical chaperones as drugs against diseases due to protein aggregation is limited by the very high active concentrations (mm range) required to mediate their effect. One of the most common chemical chaperones is 4-phenylbutyric acid (4-PBA). Despite its unfavorable pharmacokinetic properties, 4-PBA was approved as a drug to treat ornithine cycle diseases. Here, we report that 2-isopropyl-4-phenylbutanoic acid (5) has been found to be 2-10-fold more effective than 4-PBA in several in vitro models of protein aggregation. Importantly, compoundâ 5 reduced the secretion rate of autism-linked Arg451Cys Neuroligin3 (R451C NLGN3).
Asunto(s)
Fenilbutiratos/química , Proteínas/química , Animales , Moléculas de Adhesión Celular Neuronal/química , Moléculas de Adhesión Celular Neuronal/genética , Moléculas de Adhesión Celular Neuronal/metabolismo , Supervivencia Celular/efectos de los fármacos , Células HEK293 , Humanos , Proteínas de la Membrana/química , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Mutagénesis Sitio-Dirigida , Proteínas del Tejido Nervioso/química , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Células PC12 , Fenilbutiratos/farmacología , Agregado de Proteínas/efectos de los fármacos , Pliegue de Proteína , Proteínas/metabolismo , RatasRESUMEN
The discovery of how a photon is converted into a chemical signal is one of the most important achievements in the field of vision. A key molecule in this process is the visual chromophore retinal. Several eye diseases are attributed to the abnormal metabolism of retinal in the retina and the retinal pigment epithelium. Also, the accumulation of two toxic retinal derivatives, N-retinylidene-N-retinylethanolamine and the retinal dimer, can damage the retina leading to blindness. RPE65 (Retinal pigment epithelium-specific 65 kDa protein) is one of the central enzymes that regulates the metabolism of retinal and the formation of its toxic metabolites. Its inhibition might decrease the rate of the retina's degeneration by limiting the amount of retinal and its toxic byproducts. Two RPE65 inhibitors, (R)-emixustat and (R)-MB001, were recently developed for this purpose.
Asunto(s)
Inhibidores Enzimáticos/síntesis química , Éteres Fenílicos/síntesis química , Propanolaminas/síntesis química , Degeneración Retiniana/tratamiento farmacológico , cis-trans-Isomerasas/antagonistas & inhibidores , Alcanos/química , Inhibidores Enzimáticos/farmacología , Halogenación , Humanos , Isomerismo , Modelos Moleculares , Conformación Molecular , Preparaciones Farmacéuticas/síntesis química , Éteres Fenílicos/farmacología , Propanolaminas/farmacología , Retina/metabolismo , Retinaldehído/análogos & derivados , Retinaldehído/metabolismo , Relación Estructura-ActividadRESUMEN
Pruritoceptive (dermal) itch was long considered an accompanying symptom of diseases, a side effect of drug applications, or a temporary sensation induced by invading pruritogens, as produced by the stinging nettle. Due to extensive research in recent years, it was possible to provide detailed insights into the mechanism of itch mediation and modulation. Hence, it became apparent that pruritus is a complex symptom or disease in itself, which requires particular attention to improve patients' health. Here, we summarize recent findings in pruritoceptive itch, including how this sensation is triggered and modulated by diverse endogenous and exogenous pruritogens and their receptors. A differentiation between mediating pruritogen and modulating pruritogen seems to be of great advantage to understand and decipher the molecular mechanism of itch perception. Only a comprehensive view on itch sensation will provide a solid basis for targeting this long-neglected adverse sensation accompanying numerous diseases and many drug side effects. Finally, we identify critical aspects of itch perception that require future investigation.
Asunto(s)
Prurito/etiología , Prurito/patología , Animales , Factores Biológicos/efectos adversos , Factores Biológicos/metabolismo , Humanos , Prurito/metabolismo , Receptores de Superficie Celular/metabolismo , Enfermedades de la Piel/etiología , Enfermedades de la Piel/patologíaRESUMEN
The serine/threonine kinase, GSK-3, is a promising drug discovery target for treating multiple pathological disorders. Most GSK-3 inhibitors that were developed function as ATP competitive inhibitors, with typical limitations in specificity, safety and drug-induced resistance. In contrast, substrate competitive inhibitors (SCIs), are considered highly selective, and more suitable for clinical practice. The development of SCIs has been largely neglected in the past because the ambiguous, undefined nature of the substrate-binding site makes them difficult to design. In this study, we used our previously described structural models of GSK-3 bound to SCI peptides, to design a pharmacophore model and to virtually screen the "drug-like" Zinc database (~6.3 million compounds). We identified leading hits that interact with critical binding elements in the GSK-3 substrate binding site and are chemically distinct from known GSK-3 inhibitors. Accordingly, novel GSK-3 SCI compounds were designed and synthesized with IC50 values of~1-4 µM. Biological activity of the SCI compound was confirmed in cells and in primary neurons that showed increased ß-catenin levels and reduced tau phosphorylation in response to compound treatment. We have generated a new type of small molecule GSK-3 inhibitors and propose to use this strategy to further develop SCIs for other protein kinases.
Asunto(s)
Diseño de Fármacos , Descubrimiento de Drogas/métodos , Glucógeno Sintasa Quinasa 3/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/farmacología , Bibliotecas de Moléculas Pequeñas/farmacología , Animales , Sitios de Unión , Línea Celular Tumoral , Células Cultivadas , Glucógeno Sintasa Quinasa 3/química , Glucógeno Sintasa Quinasa 3/metabolismo , Humanos , Cinética , Ratones Endogámicos C57BL , Simulación del Acoplamiento Molecular , Estructura Molecular , Unión Proteica , Dominios Proteicos , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/metabolismo , Bibliotecas de Moléculas Pequeñas/química , Bibliotecas de Moléculas Pequeñas/metabolismo , Especificidad por SustratoRESUMEN
Leukocyte transendothelial migration is one of the most important step in launching an inflammatory immune response and chronic inflammation can lead to devastating diseases. Leukocyte migration inhibitors are considered as promising and potentially effective therapeutic agents to treat inflammatory and auto-immune disorders. In this study, based on previous trioxotetrahydropyrimidin based integrin inhibitors that suboptimally blocked leukocyte adhesion, twelve molecules with a modified scaffold were designed, synthesized, and tested in vitro for their capacity to block the transendothelial migration of immune cells. One of the molecules, namely, methyl 4-((2-(tert-butyl)-6-((2,4,6-trioxotetrahydropyrimidin-5(2H)-ylidene) methyl) phenoxy) methyl) benzoate, (compound 12), completely blocked leukocyte transendothelial migration, without any toxic effects on immune or endothelial cells (IC50â¯=â¯2.4⯵M). In vivo, compound 12 exhibited significant therapeutic effects in inflammatory bowel disease (IBD)/Crohn's disease, multiple sclerosis, fatty liver disease, and rheumatoid arthritis models. A detailed acute and chronic toxicity profile of the lead compound in vivo did not reveal any toxic effects. Such a type of molecule might therefore provide a unique starting point for designing a novel class of leukocyte transmigration blocking agents with broad therapeutic applications in inflammatory and auto-immune pathologies.
Asunto(s)
Linfocitos B/efectos de los fármacos , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Monocitos/efectos de los fármacos , Pirimidinas/síntesis química , Linfocitos T/efectos de los fármacos , Migración Transcelular de la Célula/efectos de los fármacos , Migración Transendotelial y Transepitelial/efectos de los fármacos , Linfocitos B/inmunología , Adhesión Celular/efectos de los fármacos , Moléculas de Adhesión Celular/inmunología , Células Endoteliales de la Vena Umbilical Humana/inmunología , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Humanos , Inflamación , Estructura Molecular , Monocitos/inmunología , Mucoproteínas/inmunología , Pirimidinas/química , Pirimidinas/farmacología , Linfocitos T/inmunología , Molécula 1 de Adhesión Celular Vascular/inmunologíaRESUMEN
BACKGROUND/AIMS: The Nrf2 signaling pathway plays a pivotal role in neutralizing excess reactive oxygen species formation and therefore enhancing the endogenous cellular protection mechanism. Thus, activating this pathway may provide therapeutic options against oxidative stress-related disorders. We have recently applied a computer-aided drug design approach to the design and synthesis of novel Nrf2 enhancers. The current study was aimed at investigating the potential beneficial impact of (E)-5-oxo-1-(4-((2,4,6-trihydroxybenzylidene)amino)phenyl)pyrrolidine-3-carboxylic acid (SK-119) in skin oxidative damage models. METHODS: SK-119, tested initially in PC-12 cells, attenuated oxidative stress-induced cytotoxicity concomitantly with Nrf2 activation. The potential impact of this compound was evaluated in skin-based disease models both in vitro (HaCaT cells) and ex vivo (human skin organ culture). RESULTS: The data clearly showed the marked anti-inflammatory and photoprotection properties of the compound; SK-119-treated cells or tissues displayed a reduction in cytokine secretion induced by lipopolysaccharides (LPS) in a manner comparable with dexamethasone. In addition, topical application of SK-119 was able to block UVB-induced oxidative stress and attenuated caspase-mediated apoptosis, DNA adduct formation, and the concomitant cellular damage. CONCLUSION: These results indicate that SK-119 is an Nrf2 activator that can be used as a prototype molecule for the development of novel treatments of dermatological disorders related to oxidative stress.
Asunto(s)
Compuestos de Bencilideno/farmacología , Factor 2 Relacionado con NF-E2/metabolismo , Estrés Oxidativo/efectos de los fármacos , Pirrolidinas/farmacología , Piel/efectos de los fármacos , Rayos Ultravioleta/efectos adversos , Adulto , Apoptosis , Caspasa 3/metabolismo , Células Cultivadas , Citocinas/metabolismo , Daño del ADN/efectos de los fármacos , Femenino , Humanos , Lipopolisacáridos/farmacología , Persona de Mediana Edad , Transducción de Señal/efectos de los fármacos , Piel/metabolismoRESUMEN
Apoptosis is thought to play a critical role in several pathological processes, such as neurodegenerative diseases (i.e. Parkinson's and Alzheimer's diseases) and various cardiovascular diseases. Despite the fact that apoptotic mechanisms are well defined, there is still no substantial therapeutic strategy to stop or even slow this process. Thus, there is an unmet need for therapeutic agents that are able to block or slow apoptosis in neurodegenerative and cardiovascular diseases. The outer mitochondrial membrane protein voltage-dependent anion channel 1 (VDAC1) is a convergence point for a variety of cell survival and death signals, including apoptosis. Recently, we demonstrated that VDAC1 oligomerization is involved in mitochondrion-mediated apoptosis. Thus, VDAC1 oligomerization represents a prime target for agents designed to modulate apoptosis. Here, high-throughput compound screening and medicinal chemistry were employed to develop compounds that directly interact with VDAC1 and prevent VDAC1 oligomerization, concomitant with an inhibition of apoptosis as induced by various means and in various cell lines. The compounds protected against apoptosis-associated mitochondrial dysfunction, restoring dissipated mitochondrial membrane potential, and thus cell energy and metabolism, decreasing reactive oxidative species production, and preventing detachment of hexokinase bound to mitochondria and disruption of intracellular Ca2+ levels. Thus, this study describes novel drug candidates with a defined mechanism of action that involves inhibition of VDAC1 oligomerization, apoptosis, and mitochondrial dysfunction. The compounds VBIT-3 and VBIT-4 offer a therapeutic strategy for treating different diseases associated with enhanced apoptosis and point to VDAC1 as a promising target for therapeutic intervention.
Asunto(s)
Apoptosis/efectos de los fármacos , Mitocondrias/metabolismo , Canal Aniónico 1 Dependiente del Voltaje/antagonistas & inhibidores , Animales , Apoptosis/genética , Señalización del Calcio/efectos de los fármacos , Señalización del Calcio/genética , Metabolismo Energético/efectos de los fármacos , Metabolismo Energético/genética , Células HEK293 , Células HeLa , Humanos , Ratones , Ratones Noqueados , Mitocondrias/genética , Multimerización de Proteína/efectos de los fármacos , Multimerización de Proteína/genética , Ratas , Canal Aniónico 1 Dependiente del Voltaje/genética , Canal Aniónico 1 Dependiente del Voltaje/metabolismoRESUMEN
The rate of glucose influx to skeletal muscles is determined primarily by the number of functional units of glucose transporter-4 (GLUT4) in the myotube plasma membrane. The abundance of GLUT4 in the plasma membrane is tightly regulated by insulin or contractile activity, which employ distinct pathways to translocate GLUT4-rich vesicles from intracellular compartments. Various studies have indicated that GLUT4 intrinsic activity is also regulated by conformational changes and/or interactions with membrane components and intracellular proteins in the vicinity of the plasma membrane. Here we show that the non-metabolizable glucose analog 3-O-methyl-d-glucose (MeGlc) augmented the rate of hexose transport into myotubes by increasing GLUT4 intrinsic activity without altering the content of the transporter in the plasma membrane. This effect was not a consequence of ATP depletion or hyperosmolar stress and did not involve Akt/PKB or AMPK signal transduction pathways. MeGlc reduced the inhibitory potency (increased Ki) of indinavir, a selective inhibitor of GLUT4, in a dose-dependent manner. Kinetic analyses indicate that MeGlc induced changes in GLUT4 or GLUT4 complexes within the plasma membrane, which enhanced the hexose transport activity and reduced the potency of indinavir inhibition. Finally, we present a simple kinetic analysis for screening and discovering low molecular weight compounds that augment GLUT4 activity.
Asunto(s)
3-O-Metilglucosa/farmacología , Transportador de Glucosa de Tipo 4/metabolismo , Fibras Musculares Esqueléticas/metabolismo , Adenosina Trifosfato/metabolismo , Animales , Transporte Biológico/efectos de los fármacos , Transporte Biológico/fisiología , Línea Celular , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Glucosa/metabolismo , Insulina/metabolismo , Cinética , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Contracción Muscular/efectos de los fármacos , Contracción Muscular/fisiología , Fibras Musculares Esqueléticas/efectos de los fármacos , Proteínas Musculares/metabolismo , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiologíaRESUMEN
PURPOSE: A series of novel polycyclic aromatic compounds that augment the rate of glucose uptake in L6 myotubes and increase glucose-stimulated insulin secretion from beta-cells were synthesized. Designing these molecules, we have aimed at the two main pathogenic mechanisms of T2D, deficient insulin secretion and diminished glucose clearance. The ultimate purpose of this work was to create a novel antidiabetic drug candidate with bi-functional mode of action. METHODS: All presented compounds were synthesized, and characterized in house. INS-1E cells and L6 myoblasts were used for the experiments. The rate of glucose uptake, mechanism of action, level of insulin secretion and the druggability of the lead compound were studied. RESULTS: The lead compound (6-(1,3-dithiepan-2-yl)-2-phenylchromane), dose- and time-dependently at the low µM range increased the rate of glucose uptake in L6 myotubes and insulin secretion in INS-1E cells. The compound exerted its effects through the activation of the LKB1 (Liver Kinase B1)-AMPK pathway. In vitro metabolic parameters of this lead compound exhibited good druggability. CONCLUSIONS: We anticipate that bi-functionality (increased rate of glucose uptake and augmented insulin secretion) will allow the lead compound to be a starting point for the development of a novel class of antidiabetic drugs.
Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Cromanos/farmacología , Glucosa/metabolismo , Hipoglucemiantes/farmacología , Células Secretoras de Insulina/efectos de los fármacos , Insulina/metabolismo , Fibras Musculares Esqueléticas/efectos de los fármacos , Animales , Transporte Biológico/efectos de los fármacos , Línea Celular , Células Cultivadas , Cromanos/química , Descubrimiento de Drogas , Activación Enzimática/efectos de los fármacos , Humanos , Hipoglucemiantes/química , Células Secretoras de Insulina/metabolismo , Fibras Musculares Esqueléticas/metabolismo , RatasRESUMEN
Protein kinase RNA-activated (PKR) plays an important role in a broad range of intracellular regulatory mechanisms and in the pathophysiology of many human diseases, including microbial and viral infections, cancer, diabetes and neurodegenerative disorders. Recently, several potent PKR inhibitors have been synthesized. However, the enzyme's multifunctional character and a multitude of PKR downstream targets have prevented the successful transformation of such inhibitors into effective drugs. Thus, the need for additional PKR inhibitors remains. With the help of computer-aided drug-discovery tools, we designed and synthesized potential PKR inhibitors. Indeed, two compounds were found to inhibit recombinant PKR in pharmacologically relevant concentrations. One compound, 6-amino-3-methyl-2-oxo-N-phenyl-2,3-dihydro-1H-benzo[d]imidazole-1-carboxamide, also showed anti-apoptotic properties. The novel molecules diversify the existing pool of PKR inhibitors and provide a basis for the future development of compounds based on PKR signal transduction mechanism.
Asunto(s)
Diseño de Fármacos , Modelos Moleculares , Inhibidores de Proteínas Quinasas/química , eIF-2 Quinasa/química , Sitios de Unión , Dominio Catalítico , Conformación Molecular , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Unión Proteica , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/farmacología , Relación Estructura-Actividad Cuantitativa , eIF-2 Quinasa/antagonistas & inhibidoresRESUMEN
The search for novel anticancer therapeutic agents is an urgent and important issue in medicinal chemistry. Here, we report on the biological activity of the copper-based bioinorganic complex Cu4 (2,4-di-tert-butyl-6-(1H-imidazo- [1, 10] phenanthrolin-2-yl)phenol)4]·10 CH3CN (2), which was tested in rat L6 myotubes, mouse NSC-34 motor neurone-like cells, and HepG-2 human liver carcinoma. Upon 96 h incubation, 2 exhibited a significant cytotoxic effect on all three types of cells via activation of two cell death mechanisms (apoptosis and necrosis). Complex 2 exhibited better potency and efficacy than the canonical cytotoxic drug cisplatin. Moreover, during shorter incubations, complex 2 demonstrated a significant SOD mimetic activity, and it was more effective and more potent than the well-known SOD mimetic TEMPOL. In addition, complex 2 was able to interact with DNA and, cleave DNA in the presence of sodium ascorbate. This study shows the potential of using polynuclear redox active compounds for developing novel anticancer drugs through SOD-mimetic redox pathways.
Asunto(s)
Mimetismo Biológico , Complejos de Coordinación/farmacología , Cobre/química , Superóxido Dismutasa/metabolismo , Animales , Antineoplásicos/química , Antineoplásicos/metabolismo , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Complejos de Coordinación/química , Complejos de Coordinación/metabolismo , Estabilidad de Medicamentos , Electroforesis en Gel de Agar , Humanos , Hierro/química , Ratones , Estructura Molecular , Ratas , Superóxido Dismutasa/química , Agua/químicaRESUMEN
We have recently generated lipophilic D-xylose derivatives that increase the rate of glucose uptake in cultured skeletal muscle cells in an AMP-activated protein kinase (AMPK)-dependent manner. The derivative 2,4:3,5-dibenzylidene-D-xylose-diethyl dithioacetal (EH-36) stimulated the rate of glucose transport by increasing the abundance of glucose transporter-4 in the plasma membrane of cultured myotubes. The present study aimed at investigating potential antihyperglycaemic effects of EH-36 in animal models of diabetes. Two animal models were treated subcutaneously with EH-36: streptozotocin-induced diabetes in C57BL/6 mice (a model of insulin-deficient type 1 diabetes), and spontaneously diabetic KKAy mice (Kuo Kondo rats carrying the A(y) yellow obese gene; insulin-resistant type 2 diabetes). The in vivo biodistribution of glucose in control and treated mice was followed with the glucose analogue 2-deoxy-2-[(18) F]-D-glucose; the rate of glucose uptake in excised soleus muscles was measured with [(3) H]-2-deoxy-D-glucose. Pharmacokinetic parameters were determined by non-compartmental analysis of the in vivo data. The effective blood EH-36 concentration in treated animals was 2 µM. It reduced significantly the blood glucose levels in both types of diabetic mice and also corrected the typical compensatory hyperinsulinaemia of KKAy mice. EH-36 markedly increased glucose transport in vivo into skeletal muscle and heart, but not to adipose tissue. This stimulatory effect was mediated by Thr(172) -phosphorylation in AMPK. Biochemical tests in treated animals and acute toxicological examinations showed that EH-36 was well tolerated and not toxic to the mice. These findings indicate that EH-36 is a promising prototype molecule for the development of novel antidiabetic drugs.
Asunto(s)
Acetales/uso terapéutico , Compuestos de Bencilideno/uso terapéutico , Compuestos Bicíclicos Heterocíclicos con Puentes/uso terapéutico , Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Hipoglucemiantes/uso terapéutico , Tioglicósidos/uso terapéutico , Quinasas de la Proteína-Quinasa Activada por el AMP , Acetales/administración & dosificación , Animales , Compuestos de Bencilideno/administración & dosificación , Transporte Biológico/efectos de los fármacos , Glucemia/análisis , Compuestos Bicíclicos Heterocíclicos con Puentes/administración & dosificación , Células Cultivadas , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Transportador de Glucosa de Tipo 4/biosíntesis , Corazón/efectos de los fármacos , Hipoglucemiantes/administración & dosificación , Masculino , Ratones , Ratones Endogámicos C57BL , Fibras Musculares Esqueléticas/efectos de los fármacos , Fibras Musculares Esqueléticas/metabolismo , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/metabolismo , Proteínas Quinasas/metabolismo , Ratas , Ratas Wistar , Tioglicósidos/administración & dosificación , TritioRESUMEN
Human α1-antitrypsin (hAAT) has two distinguishing functions: anti-protease activity and regulation of the immune system. In the present study we hypothesized that those two protein functions are mediated by different structural domains on the hAAT surface. Indeed, such biologically active immunoregulatory sites (not associated with canonical anti-protease activity) on the surface of hAAT were identified by in silico methods. Several peptides were derived from those immunoregulatory sites. Four peptides exhibited impressive biological effects in pharmacological concentration ranges. Peptidomimetic (14) was developed, based on the structure of the most druggable and active peptide. The compound exhibited a potent anti-inflammatory activity in vitro and in vivo. Such a compound could be used as a basis for developing novel anti-inflammatory drug candidates and as a research tool for better understanding hAAT functions.