RESUMEN
Modern retrosynthetic analysis in organic chemistry is based on the principle of polar relationships between functional groups to guide the design of synthetic routes1. This method, termed polar retrosynthetic analysis, assigns partial positive (electrophilic) or negative (nucleophilic) charges to constituent functional groups in complex molecules followed by disconnecting bonds between opposing charges2-4. Although this approach forms the basis of undergraduate curriculum in organic chemistry5 and strategic applications of most synthetic methods6, the implementation often requires a long list of ancillary considerations to mitigate chemoselectivity and oxidation state issues involving protecting groups and precise reaction choreography3,4,7. Here we report a radical-based Ni/Ag-electrocatalytic cross-coupling of substituted carboxylic acids, thereby enabling an intuitive and modular approach to accessing complex molecular architectures. This new method relies on a key silver additive that forms an active Ag nanoparticle-coated electrode surface8,9 in situ along with carefully chosen ligands that modulate the reactivity of Ni. Through judicious choice of conditions and ligands, the cross-couplings can be rendered highly diastereoselective. To demonstrate the simplifying power of these reactions, concise syntheses of 14 natural products and two medicinally relevant molecules were completed.
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Productos Biológicos , Técnicas de Química Sintética , Descarboxilación , Electroquímica , Electrodos , Preparaciones Farmacéuticas , Ácidos Carboxílicos/química , Nanopartículas del Metal/química , Oxidación-Reducción , Plata/química , Productos Biológicos/síntesis química , Productos Biológicos/química , Níquel/química , Ligandos , Preparaciones Farmacéuticas/síntesis química , Preparaciones Farmacéuticas/química , Electroquímica/métodos , Técnicas de Química Sintética/métodosRESUMEN
The first enantioselective decarboxylative Negishi-type alkylations of α-oxy carboxylic acids are reported via the intermediacy of redox-active esters (RAEs). This transformation enables a radical-based retrosynthesis of seemingly trivial enantiopure dialkyl carbinols. This article includes a discussion of the history of such couplings, the retrosynthetic ramifications of such a coupling, the development of general conditions, and an extensive series of applications that vividly demonstrate how it can simplify synthesis.
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Ácidos Carboxílicos , Metanol , Catálisis , Ésteres , EstereoisomerismoRESUMEN
The stabilization of protein complexes has emerged as a promising modality, expanding the number of entry points for novel therapeutic intervention. Targeting proteins that mediate protein-protein interactions (PPIs), such as hub proteins, is equally challenging and rewarding as they offer an intervention platform for a variety of diseases, due to their large interactome. 14-3-3 hub proteins bind phosphorylated motifs of their interaction partners in a conserved binding channel. The 14-3-3 PPI interface is consequently only diversified by its different interaction partners. Therefore, it is essential to consider, additionally to the potency, also the selectivity of stabilizer molecules. Targeting a lysine residue at the interface of the composite 14-3-3 complex, which can be targeted explicitly via aldimine-forming fragments, we studied the de novo design of PPI stabilizers under consideration of potential selectivity. By applying cooperativity analysis of ternary complex formation, we developed a reversible covalent molecular glue for the 14-3-3/Pin1 interaction. This small fragment led to a more than 250-fold stabilization of the 14-3-3/Pin1 interaction by selective interfacing with a unique tryptophan in Pin1. This study illustrates how cooperative complex formation drives selective PPI stabilization. Further, it highlights how specific interactions within a hub proteins interactome can be stabilized over other interactions with a common binding motif.
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Proteínas 14-3-3/química , Iminas/química , Humanos , Modelos Moleculares , Estructura Molecular , Peptidilprolil Isomerasa de Interacción con NIMA/química , Estabilidad ProteicaRESUMEN
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.
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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
Despite the highly strained nature of cyclopropanes possessing three vicinal quaternary carbon stereocenters, the regio- and diastereoselective copper-catalyzed carbomagnesiation reaction of cyclopropenes provides an easy and efficient access to these novel persubstituted cyclopropyl cores with a complete regio- and diastereoselectivity.
RESUMEN
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
We report the synthesis of substituted indolizidines and quinolizidines using the modified Julia olefination previously developed on imides. The study focuses on the regioselectivity of this reaction on unsymmetrically substituted imides. The scope and regioselectivity of the reaction are presented here, and its utility as a tool for synthesizing natural products is demonstrated through the total synthesis of Pandalizine A.
RESUMEN
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.
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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
Small-molecule stabilization of protein-protein interactions (PPIs) is a promising concept in drug discovery, however the question how to identify or design chemical starting points in a "bottom-up" approach is largely unanswered. We report a novel concept for identifying initial chemical matter for PPI stabilization based on imine-forming fragments. The imine bond offers a covalent anchor for site-directed fragment targeting, whereas its transient nature enables efficient analysis of structure-activity relationships. This bond enables fragment identification and optimisation using protein crystallography. We report novel fragments that bind specifically to a lysine at the PPI interface of the p65-subunit-derived peptide of NF-κB with the adapter protein 14-3-3. Those fragments that subsequently establish contacts with the p65-derived peptide, rather than with 14-3-3, efficiently stabilize the 14-3-3/p65 complex and offer novel starting points for molecular glues.
Asunto(s)
Proteínas 14-3-3/química , Iminas/química , Bibliotecas de Moléculas Pequeñas/química , Factor de Transcripción ReIA/química , Estructura Molecular , Unión Proteica , Estabilidad Proteica , Relación Estructura-ActividadRESUMEN
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.
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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
The human genome displays a rich fossil record of past gammaretrovirus infections, yet no current epidemic is evident, despite environmental exposure to viruses that infect human cells in vitro Feline leukemia viruses (FeLVs) rank high on this list, but neither domestic nor workplace exposure has been associated with detectable serological responses. Nonspecific inactivation of gammaretroviruses by serum factors appears insufficient to explain these observations. To investigate further, we explored the susceptibilities of primary and established human cell lines to FeLV-B, the most likely zoonotic variant. Fully permissive infection was common in cancer-derived cell lines but was also a feature of nontransformed keratinocytes and lung fibroblasts. Cells of hematopoietic origin were generally less permissive and formed discrete groups on the basis of high or low intracellular protein expression and virion release. Potent repression was observed in primary human blood mononuclear cells and a subset of leukemia cell lines. However, the early steps of reverse transcription and integration appear to be unimpaired in nonpermissive cells. FeLV-B was subject to GâA hypermutation with a predominant APOBEC3G signature in partially permissive cells but was not mutated in permissive cells or in nonpermissive cells that block secondary viral spread. Distinct cellular barriers that protect primary human blood cells are likely to be important in protection against zoonotic infection with FeLV.IMPORTANCE Domestic exposure to gammaretroviruses such as feline leukemia viruses (FeLVs) occurs worldwide, but the basis of human resistance to infection remains incompletely understood. The potential threat is evident from the human genome sequence, which reveals many past epidemics of gammaretrovirus infection, and from recent cross-species jumps of gammaretroviruses from rodents to primates and marsupials. This study examined resistance to infection at the cellular level with the most prevalent human cell-tropic FeLV variant, FeLV-B. We found that blood cells are uniquely resistant to infection with FeLV-B due to the activity of cellular enzymes that mutate the viral genome. A second block, which appears to suppress viral gene expression after the viral genome has integrated into the host cell genome, was identified. Since cells derived from other normal human cell types are fully supportive of FeLV replication, innate resistance of blood cells could be critical in protecting against cross-species infection.
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Virus de la Leucemia Felina/fisiología , Infecciones por Retroviridae/virología , Desaminasa APOBEC-3G/genética , Desaminasa APOBEC-3G/metabolismo , Animales , Gatos , Línea Celular Tumoral , Susceptibilidad a Enfermedades , Expresión Génica , Genoma Viral , Células HEK293 , Humanos , Mutación , Especificidad de la Especie , Tropismo Viral , Integración Viral , Replicación Viral , Zoonosis/virologíaRESUMEN
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.
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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 , RatasAsunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Carcinoma Adenoescamoso/terapia , Cesárea , Quimioradioterapia , Terapia Neoadyuvante , Complicaciones Neoplásicas del Embarazo/terapia , Neoplasias del Cuello Uterino/terapia , Anciano , Antineoplásicos/uso terapéutico , Braquiterapia/métodos , Carboplatino/administración & dosificación , Carcinoma Adenoescamoso/diagnóstico por imagen , Cisplatino/uso terapéutico , Femenino , Humanos , Recién Nacido , Imagen por Resonancia Magnética , Estadificación de Neoplasias , Paclitaxel/administración & dosificación , Tomografía Computarizada por Tomografía de Emisión de Positrones , Periodo Posparto , Embarazo , Complicaciones Neoplásicas del Embarazo/diagnóstico por imagen , Resultado del Embarazo , Segundo Trimestre del Embarazo , Radioterapia de Intensidad Modulada/métodos , Ultrasonografía , Neoplasias del Cuello Uterino/diagnóstico por imagenRESUMEN
Feline leukemia virus (FeLV) is a naturally transmitted gammaretrovirus that infects domestic cats. FeLV-945, the predominant isolate associated with non-T-cell disease in a natural cohort, is a member of FeLV subgroup A but differs in sequence from the FeLV-A prototype, FeLV-A/61E, in the surface glycoprotein (SU) and long terminal repeat (LTR). Substitution of the FeLV-945 LTR into FeLV-A/61E resulted in pathogenesis indistinguishable from that of FeLV-A/61E, namely, thymic lymphoma of T-cell origin. In contrast, substitution of both FeLV-945 LTR and SU into FeLV-A/61E resulted in multicentric lymphoma of non-T-cell origin. These results implicated the FeLV-945 SU as a determinant of pathogenic spectrum. The present study was undertaken to test the hypothesis that FeLV-945 SU can act in the absence of other unique sequence elements of FeLV-945 to determine the disease spectrum. Substitution of FeLV-A/61E SU with that of FeLV-945 altered the clinical presentation and resulted in tumors that demonstrated expression of CD45R in the presence or absence of CD3. Despite the evident expression of CD45R, a typical B-cell marker, T-cell receptor beta (TCRß) gene rearrangement indicated a T-cell origin. Tumor cells were detectable in bone marrow and blood at earlier times during the disease process, and the predominant SU genes from proviruses integrated in tumor DNA carried markers of genetic recombination. The findings demonstrate that FeLV-945 SU alters pathogenesis, although incompletely, in the absence of FeLV-945 LTR. Evidence demonstrates that FeLV-945 SU and LTR are required together to fully recapitulate the distinctive non-T-cell disease outcome seen in the natural cohort.
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Virus de la Leucemia Felina/patogenicidad , Linfoma/patología , Glicoproteínas de Membrana/metabolismo , Infecciones por Retroviridae/virología , Secuencias Repetidas Terminales/genética , Neoplasias del Timo/patología , Infecciones Tumorales por Virus/virología , Secuencia de Aminoácidos , Animales , Southern Blotting , Gatos , ADN Viral/genética , Progresión de la Enfermedad , Femenino , Técnicas para Inmunoenzimas , Virus de la Leucemia Felina/fisiología , Linfoma/genética , Linfoma/virología , Glicoproteínas de Membrana/genética , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Infecciones por Retroviridae/metabolismo , Infecciones por Retroviridae/patología , Homología de Secuencia de Aminoácido , Tasa de Supervivencia , Neoplasias del Timo/genética , Neoplasias del Timo/virología , Infecciones Tumorales por Virus/metabolismo , Infecciones Tumorales por Virus/patología , Proteínas del Envoltorio Viral/genética , Proteínas del Envoltorio Viral/metabolismoRESUMEN
Fragment-based drug discovery has played an important role in medicinal chemistry and pharmaceutical research. Despite numerous demonstrated successes, the limited diversity and overrepresentation of planar, sp2-rich structures in commercial libraries often hamper the full potential of this approach. Hence, the thorough design of screening libraries inevitably determines the probability for meaningful hits and subsequent structural elaboration. Against this background, we present the generation of an exclusive fragment library based on iterative entry nomination by a specifically designed computational workflow: "Fragtory". Following a pharmacophore diversity-driven approach, we used Fragtory in an interdisciplinary academic setting to guide both tailored synthesis efforts and the implementation of in-house compounds to build a curated 288-member library of sp3-enriched fragments. Subsequent NMR screens against a model protein and hit validation by protein crystallography led to the identification of structurally novel ligands that were further characterized by isothermal titration calorimetry, demonstrating the applicability of our experimental approach.
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Descubrimiento de Drogas , Farmacóforo , Proteínas , Unión Proteica , Ligandos , Diseño de FármacosRESUMEN
Attention-deficit hyperactivity disorder (ADHD) affects approximately 5% of children and adolescents globally and is associated with negative life outcomes and socioeconomic costs. First-generation ADHD treatments were predominantly pharmacological; however, increased understanding of biological, psychological, and environmental factors contributing to ADHD has expanded non-pharmacological treatment possibilities. This Review provides an updated evaluation of the efficacy and safety of non-pharmacological treatments for paediatric ADHD, discussing the quality and level of evidence for nine intervention categories. Unlike medication, no non-pharmacological treatments showed a consistent strong effect on ADHD symptoms. When considering broad outcomes (eg, impairment, caregiver stress, and behavioural improvement), multicomponent (cognitive) behaviour therapy joined medication as a primary ADHD treatment. With respect to secondary treatments, polyunsaturated fatty acids showed a consistent modest effect on ADHD symptoms when taken for at least 3 months. Additionally, mindfulness and multinutrient supplementation with four or more ingredients showed modest efficacy on non-symptom outcomes. All other non-pharmacological treatments were safe; clinicians might tolerate their use but should educate families of childrenand adolescents with ADHD on the disadvantages, including costs, burden to the service user, absence of proven efficacy relative to other treatments, and delay of proven treatment.
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Trastorno por Déficit de Atención con Hiperactividad , Terapia Cognitivo-Conductual , Humanos , Niño , Adolescente , Trastorno por Déficit de Atención con Hiperactividad/tratamiento farmacológicoRESUMEN
OBJECTIVE: Dextromethorphan (DXM) is a commonly used antitussive medication with positive effects in people with type 2 diabetes mellitus, since it increases glucose tolerance and protects pancreatic islets from cell death. However, its use as an antidiabetic medication is limited due to its central nervous side effects and potential use as a recreational drug. Therefore, we recently modified DXM chemically to reduce its blood-brain barrier (BBB) penetration and central side effects. However, our best compound interacted with the cardiac potassium channel hERG (human ether-à-go-go-related gene product) and the µ-opioid receptor (MOR). Thus, the goal of this study was to reduce the interaction of our compound with these targets, while maintaining its beneficial properties. METHODS: Receptor and channel binding assays were conducted to evaluate the drug safety of our DXM derivative. Pancreatic islets were used to investigate the effect of the compound on insulin secretion and islet cell survival. Via liquor collection from the brain and a behavioral assay, we analyzed the BBB permeability. By performing intraperitoneal and oral glucose tolerance tests as well as pharmacokinetic analyses, the antidiabetic potential and elimination half-life were investigated, respectively. To analyze the islet cell-protective effect, we used fluorescence microscopy as well as flow cytometric analyses. RESULTS: Here, we report the design and synthesis of an optimized, orally available BBB-impermeable DXM derivative with lesser binding to hERG and MOR than previous ones. We also show that the new compound substantially enhances glucose-stimulated insulin secretion (GSIS) from mouse and human islets and glucose tolerance in mice as well as protects pancreatic islets from cell death induced by reactive oxygen species and that it amplifies the effects of tirzepatide on GSIS and islet cell viability. CONCLUSIONS: We succeeded to design and synthesize a novel morphinan derivative that is BBB-impermeable, glucose-lowering and islet cell-protective and has good drug safety despite its morphinan and imidazole structures.
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Diabetes Mellitus Tipo 2 , Islotes Pancreáticos , Morfinanos , Ratones , Humanos , Animales , Diabetes Mellitus Tipo 2/metabolismo , Insulina/metabolismo , Morfinanos/metabolismo , Morfinanos/farmacología , Islotes Pancreáticos/metabolismo , Glucosa/metabolismo , Hipoglucemiantes/farmacología , Estrés OxidativoRESUMEN
BACKGROUND AND PURPOSE: Super-resolutionreconstruction (SRR) can be used to reconstruct 3-dimensional (3D) high-resolution (HR) volume from several 2-dimensional (2D) low-resolution (LR) stacks of MRI slices. The purpose is to compare lengthy 2D T2-weighted HR image acquisition of neonatal subjects with 3D SRR from several LR stacks in terms of image quality for clinical and morphometric assessments. METHODS: LR brain images were acquired from neonatal subjects to reconstruct isotropic 3D HR volumes by using SRR algorithm. Quality assessments were done by an experienced pediatric radiologist using scoring criteria adapted to newborn anatomical landmarks. The Wilcoxon signed-rank test was used to compare scoring results between HR and SRR images. For quantitative assessments, morphology-based segmentation was performed on both HR and SRR images and Dice coefficients between the results were computed. Additionally, simple linear regression was performed to compare the tissue volumes. RESULTS: No statistical difference was found between HR and SRR structural scores using Wilcoxon signed-rank test (p = .63, Z = .48). Regarding segmentation results, R2 values for the volumes of gray matter, white matter, cerebrospinal fluid, basal ganglia, cerebellum, and total brain volume including brain stem ranged between .95 and .99. Dice coefficients between the segmented regions from HR and SRR ranged between .83 ± .04 and .96 ± .01. CONCLUSION: Qualitative and quantitative assessments showed that 3D SRR of several LR images produces images that are of comparable quality to standard 2D HR image acquisition for healthy neonatal imaging without loss of anatomical details with similar edge definition allowing the detection of fine anatomical structures and permitting comparable morphometric measurement.
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Imagenología Tridimensional , Imagen por Resonancia Magnética , Algoritmos , Encéfalo/diagnóstico por imagen , Niño , Humanos , Imagenología Tridimensional/métodos , Recién Nacido , Imagen por Resonancia Magnética/métodos , NeuroimagenRESUMEN
BACKGROUND: Feline leukemia virus (FeLV)-945, a member of the FeLV-A subgroup, was previously isolated from a cohort of naturally infected cats. An unusual multicentric lymphoma of non-T-cell origin was observed in natural and experimental infection with FeLV-945. Previous studies implicated the FeLV-945 surface glycoprotein (SU) as a determinant of disease outcome by an as yet unknown mechanism. The present studies demonstrate that FeLV-945 SU confers distinctive properties of binding to the cell surface receptor. RESULTS: Virions bearing the FeLV-945 Env protein were observed to bind the cell surface receptor with significantly increased efficiency, as was soluble FeLV-945 SU protein, as compared to the corresponding virions or soluble protein from a prototype FeLV-A isolate. SU proteins cloned from other cohort isolates exhibited increased binding efficiency comparable to or greater than FeLV-945 SU. Mutational analysis implicated a domain containing variable region B (VRB) to be the major determinant of increased receptor binding, and identified a single residue, valine 186, to be responsible for the effect. CONCLUSIONS: The FeLV-945 SU protein binds its cell surface receptor, feTHTR1, with significantly greater efficiency than does that of prototype FeLV-A (FeLV-A/61E) when present on the surface of virus particles or in soluble form, demonstrating a 2-fold difference in the relative dissociation constant. The results implicate a single residue, valine 186, as the major determinant of increased binding affinity. Computational modeling suggests a molecular mechanism by which residue 186 interacts with the receptor-binding domain through residue glutamine 110 to effect increased binding affinity. Through its increased receptor binding affinity, FeLV-945 SU might function in pathogenesis by increasing the rate of virus entry and spread in vivo, or by facilitating entry into a novel target cell with a low receptor density.
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Virus de la Leucemia Felina/patogenicidad , Glicoproteínas de Membrana/metabolismo , Receptores Virales/metabolismo , Proteínas Oncogénicas de Retroviridae/metabolismo , Proteínas del Envoltorio Viral/metabolismo , Tropismo Viral , Acoplamiento Viral , Secuencia de Aminoácidos , Sustitución de Aminoácidos/genética , Animales , Gatos , Línea Celular , Modelos Moleculares , Datos de Secuencia Molecular , Mutación Missense , Conformación Proteica , Valina/genéticaRESUMEN
Protein-protein modulation has emerged as a proven approach to drug discovery. While significant progress has been gained in developing protein-protein interaction (PPI) inhibitors, the orthogonal approach of PPI stabilization lacks established methodologies for drug design. Here, we report the systematic â³bottom-upâ³ development of a reversible covalent PPI stabilizer. An imine bond was employed to anchor the stabilizer at the interface of the 14-3-3/p65 complex, leading to a molecular glue that elicited an 81-fold increase in complex stabilization. Utilizing protein crystallography and biophysical assays, we deconvoluted how chemical properties of a stabilizer translate to structural changes in the ternary 14-3-3/p65/molecular glue complex. Furthermore, we explore how this leads to high cooperativity and increased stability of the complex.