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1.
Purinergic Signal ; 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38879664

RESUMEN

The human equilibrative nucleoside transporter 1 (SLC29A1, hENT1) is a solute carrier that modulates the passive transport of nucleosides and nucleobases, such as adenosine. This nucleoside regulates various physiological processes, such as vasodilation and -constriction, neurotransmission and immune defense. Marketed drugs such as dilazep and dipyridamole have proven useful in cardiovascular afflictions, but the application of hENT1 inhibitors can be beneficial in a number of other diseases. In this study, 39 derivatives of dilazep's close analogue ST7092 were designed, synthesized and subsequently assessed using [3H]NBTI displacement assays and molecular docking. Different substitution patterns of the trimethoxy benzoates of ST7092 reduced interactions within the binding pocket, resulting in diminished hENT1 affinity. Conversely, [3H]NBTI displacement by potentially covalent compounds 14b, 14c, and 14d resulted in high affinities (Ki values between 1.1 and 17.5 nM) for the transporter, primarily by the ability of accommodating the inhibitors in various ways in the binding pocket. However, any indication of covalent binding with amino acid residue C439 remained absent, conceivably as a result of decreased nucleophilic residue reactivity. In conclusion, this research introduces novel dilazep derivatives that are active as hENT1 inhibitors, along with the first high affinity dilazep derivatives equipped with an electrophilic warhead. These findings will aid the rational and structure-based development of novel hENT1 inhibitors and pharmacological tools to study hENT1's function, binding mechanisms, and its relevance in (patho)physiological conditions.

2.
ACS Chem Biol ; 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38920052

RESUMEN

Small molecular tool compounds play an essential role in the study of G protein-coupled receptors (GPCRs). However, tool compounds most often occupy the orthosteric binding site, hampering the study of GPCRs upon ligand binding. To overcome this problem, ligand-directed labeling techniques have been developed that leave a reporter group covalently bound to the GPCR, while allowing subsequent orthosteric ligands to bind. In this work, we applied such a labeling strategy to the adenosine A2B receptor (A2BAR). We have synthetically implemented the recently reported N-acyl-N-alkyl sulfonamide (NASA) warhead into a previously developed ligand and show that the binding of the A2BAR is not restricted by NASA incorporation. Furthermore, we have investigated ligand-directed labeling of the A2BAR using SDS-PAGE, flow cytometric, and mass spectrometry techniques. We have found one of the synthesized probes to specifically label the A2BAR, although detection was hindered by nonspecific protein labeling most likely due to the intrinsic reactivity of the NASA warhead. Altogether, this work aids the future development of ligand-directed probes for the detection of GPCRs.

3.
BMC Pulm Med ; 24(1): 207, 2024 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-38671448

RESUMEN

OBJECTIVE: The aim of this research was to examine how penehyclidine hydrochloride (PHC) impacts the occurrence of pyroptosis in lung tissue cells within a rat model of lung ischemia-reperfusion injury. METHODS: Twenty-four Sprague Dawley (SD) rats, weighing 250 g to 270 g, were randomly distributed into three distinct groups as outlined below: a sham operation group (S group), a control group (C group), and a test group (PHC group). Rats in the PHC group received a preliminary intravenous injection of PHC at a dose of 3 mg/kg. At the conclusion of the experiment, lung tissue and blood samples were collected and properly stored for subsequent analysis. The levels of malondialdehyde, superoxide dismutase, and myeloperoxidase in the lung tissue, as well as IL-18 and IL-1ß in the blood serum, were assessed using an Elisa kit. Pyroptosis-related proteins, including Caspase1 p20, GSDMD-N, and NLRP3, were detected through the western blot method. Additionally, the dry-to-wet ratio (D/W) of the lung tissue and the findings from the blood gas analysis were also documented. RESULTS: In contrast to the control group, the PHC group showed enhancements in oxygenation metrics, reductions in oxidative stress and inflammatory reactions, and a decrease in lung injury. Additionally, the PHC group exhibited lowered levels of pyroptosis-associated proteins, including the N-terminal segment of gasdermin D (GSDMD-N), caspase-1p20, and nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3). CONCLUSION: Pre-administration of PHC has the potential to mitigate lung ischemia-reperfusion injuries by suppressing the pyroptosis of lung tissue cells, diminishing inflammatory reactions, and enhancing lung function. The primary mechanism behind anti-pyroptotic effect of PHC appears to involve the inhibition of oxidative stress.


Asunto(s)
Gasderminas , Pulmón , Piroptosis , Quinuclidinas , Ratas Sprague-Dawley , Daño por Reperfusión , Animales , Piroptosis/efectos de los fármacos , Daño por Reperfusión/tratamiento farmacológico , Daño por Reperfusión/prevención & control , Ratas , Quinuclidinas/farmacología , Pulmón/efectos de los fármacos , Pulmón/patología , Pulmón/metabolismo , Masculino , Malondialdehído/metabolismo , Modelos Animales de Enfermedad , Interleucina-1beta/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Interleucina-18/metabolismo , Proteínas de Unión a Fosfato/metabolismo , Superóxido Dismutasa/metabolismo , Peroxidasa/metabolismo , Estrés Oxidativo/efectos de los fármacos , Caspasa 1/metabolismo , Lesión Pulmonar/tratamiento farmacológico , Lesión Pulmonar/metabolismo
4.
ACS Chem Neurosci ; 15(7): 1424-1431, 2024 04 03.
Artículo en Inglés | MEDLINE | ID: mdl-38478848

RESUMEN

Excitatory amino acid transporters (EAATs) are important regulators of amino acid transport and in particular glutamate. Recently, more interest has arisen in these transporters in the context of neurodegenerative diseases. This calls for ways to modulate these targets to drive glutamate transport, EAAT2 and EAAT3 in particular. Several inhibitors (competitive and noncompetitive) exist to block glutamate transport; however, activators remain scarce. Recently, GT949 was proposed as a selective activator of EAAT2, as tested in a radioligand uptake assay. In the presented research, we aimed to validate the use of GT949 to activate EAAT2-driven glutamate transport by applying an innovative, impedance-based, whole-cell assay (xCELLigence). A broad range of GT949 concentrations in a variety of cellular environments were tested in this assay. As expected, no activation of EAAT3 could be detected. Yet, surprisingly, no biological activation of GT949 on EAAT2 could be observed in this assay either. To validate whether the impedance-based assay was not suited to pick up increased glutamate uptake or if the compound might not induce activation in this setup, we performed radioligand uptake assays. Two setups were utilized; a novel method compared to previously published research, and in a reproducible fashion copying the methods used in the existing literature. Nonetheless, activation of neither EAAT2 nor EAAT3 could be observed in these assays. Furthermore, no evidence of GT949 binding or stabilization of purified EAAT2 could be observed in a thermal shift assay. To conclude, based on experimental evidence in the present study GT949 requires specific assay conditions, which are difficult to reproduce, and the compound cannot simply be classified as an activator of EAAT2 based on the presented evidence. Hence, further research is required to develop the tools needed to identify new EAAT modulators and use their potential as a therapeutic target.


Asunto(s)
Transportador 2 de Aminoácidos Excitadores , Ácido Glutámico , Transportador 2 de Aminoácidos Excitadores/metabolismo , Impedancia Eléctrica , Ácido Glutámico/metabolismo , Transporte Biológico , Transportador 3 de Aminoácidos Excitadores/metabolismo
5.
J Org Chem ; 89(3): 2032-2038, 2024 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-38226644

RESUMEN

The construction of a C-C bond by cross-coupling of two different C-H bonds with the release of hydrogen gas represents an ideal yet challenging bond formation strategy. Herein, we report a photocatalytic metal-free cross-coupling of benzylic and aldehydic C-H bonds by synergistic catalysis of organophotocatalyst 4CzIPN and a thiol, which affords the corresponding α-aryl ketones in acceptable yields along with hydrogen evolution. The mechanistic investigation indicates a radical-radical coupling to give an intermediary alcohol, followed by an acceptorless alcohol dehydrogenation.

6.
Front Mol Biosci ; 10: 1286673, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38074092

RESUMEN

Glutamate is an essential excitatory neurotransmitter and an intermediate for energy metabolism. Depending on the tumor site, cancer cells have increased or decreased expression of excitatory amino acid transporter 1 or 2 (EAAT1/2, SLC1A3/2) to regulate glutamate uptake for the benefit of tumor growth. Thus, EAAT1/2 may be an attractive target for therapeutic intervention in oncology. Genetic variation of EAAT1 has been associated with rare cases of episodic ataxia, but the occurrence and functional contribution of EAAT1 mutants in other diseases, such as cancer, is poorly understood. Here, 105 unique somatic EAAT1 mutations were identified in cancer patients from the Genomic Data Commons dataset. Using EAAT1 crystal structures and in silico studies, eight mutations were selected based on their close proximity to the orthosteric or allosteric ligand binding sites and the predicted change in ligand binding affinity. In vitro functional assessment in a live-cell, impedance-based phenotypic assay demonstrated that these mutants differentially affect L-glutamate and L-aspartate transport, as well as the inhibitory potency of an orthosteric (TFB-TBOA) and allosteric (UCPH-101) inhibitor. Moreover, two episodic ataxia-related mutants displayed functional responses that were in line with literature, which confirmed the validity of our assay. Of note, ataxia-related mutant M128R displayed inhibitor-induced functional responses never described before. Finally, molecular dynamics (MD) simulations were performed to gain mechanistic insights into the observed functional effects. Taken together, the results in this work demonstrate 1) the suitability of the label-free phenotypic method to assess functional variation of EAAT1 mutants and 2) the opportunity and challenges of using in silico techniques to rationalize the in vitro phenotype of disease-relevant mutants.

7.
J Med Chem ; 66(16): 11399-11413, 2023 08 24.
Artículo en Inglés | MEDLINE | ID: mdl-37531576

RESUMEN

The adenosine A3 receptor (A3AR) is a G protein-coupled receptor (GPCR) that exerts immunomodulatory effects in pathophysiological conditions such as inflammation and cancer. Thus far, studies toward the downstream effects of A3AR activation have yielded contradictory results, thereby motivating the need for further investigations. Various chemical and biological tools have been developed for this purpose, ranging from fluorescent ligands to antibodies. Nevertheless, these probes are limited by their reversible mode of binding, relatively large size, and often low specificity. Therefore, in this work, we have developed a clickable and covalent affinity-based probe (AfBP) to target the human A3AR. Herein, we show validation of the synthesized AfBP in radioligand displacement, SDS-PAGE, and confocal microscopy experiments as well as utilization of the AfBP for the detection of endogenous A3AR expression in flow cytometry experiments. Ultimately, this AfBP will aid future studies toward the expression and function of the A3AR in pathologies.


Asunto(s)
Adenosina , Receptor de Adenosina A3 , Humanos , Adenosina/farmacología , Receptor de Adenosina A3/metabolismo , Expresión Génica , Receptores Acoplados a Proteínas G , Agonistas del Receptor de Adenosina A3/farmacología
8.
Org Lett ; 25(29): 5486-5491, 2023 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-37470382

RESUMEN

Controllable oxidation of alcohols to carbonyls is one of the fundamental transformations in organic chemistry. Herein, we report an unprecedented visible-light-mediated metal-free oxidation of alcohols to carbonyls with hydrogen evolution. By synergistic combination of organophotocatalyst 4CzIPN and a thiol hydrogen atom transfer catalyst, a broad range of alcohols, including primary and secondary benzylic alcohols as well as aliphatic alcohols, were readily oxidized to carbonyls in moderate to excellent yields. A site-selective oxidation has also been achieved by this protocol. Mechanistic investigation indicates that the oxidation proceeds through an oxidative radical-polar crossover process to obtain an α-oxy carbon cation.

9.
Org Lett ; 25(26): 4776-4781, 2023 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-37358479

RESUMEN

P(NMe2)3-mediated substrate-controlled annulations of azoalkenes with α-dicarbonyl compounds are reported, where the azoalkenes serve as either four or five-atom synthons chemoselectively. The azoalkene participates in annulation with isatins as a four-atom synthon to furnish the spirooxindole-pyrazolines, whereas it functions as a novel five-atom synthon in annulation with aroylformates, thereby leading to chemo- and stereoselective formation of pyrazolones. The synthetic utilities of the annulations have been demonstrated, and a novel TEMPO-mediated decarbonylation reaction is unveiled.

10.
ACS Omega ; 8(15): 14097-14112, 2023 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-37091407

RESUMEN

We herein disclose the microwave-assisted synthesis of previously unreported 6-methoxy-5,6-dihydro-5-azapurines, whose purine-like scaffold is promising for drug discovery. The method is simple, fast, and relies on easily accessible reagents such as trimethyl orthoformate, acetic acid, and aminotriazole-derived N,N'-disubstituted formamidines. The preliminary biological evaluation revealed that selected representatives of synthesized 6-methoxy-5,6-dihydro-5-azapurines dose-dependently reduce the viability of HepG2 and A549 cancer cells having little to no influence on five tested purinergic receptors.

11.
ACS Chem Biol ; 17(11): 3131-3139, 2022 11 18.
Artículo en Inglés | MEDLINE | ID: mdl-36279267

RESUMEN

G protein-coupled receptors (GPCRs) have been known for decades as attractive drug targets. This has led to the development and approval of many ligands targeting GPCRs. Although ligand binding effects have been studied thoroughly for many GPCRs, there are multiple aspects of GPCR signaling that remain poorly understood. The reasons for this are the difficulties that are encountered upon studying GPCRs, for example, a poor solubility and low expression levels. In this work, we have managed to overcome some of these issues by developing an affinity-based probe for a prototypic GPCR, the adenosine A1 receptor (A1AR). Here, we show the design, synthesis, and biological evaluation of this probe in various biochemical assays, such as SDS-PAGE, confocal microscopy, and chemical proteomics.


Asunto(s)
Receptores Acoplados a Proteínas G , Transducción de Señal , Receptores Acoplados a Proteínas G/metabolismo , Ligandos , Adenosina/farmacología
12.
World J Clin Cases ; 10(24): 8506-8513, 2022 Aug 26.
Artículo en Inglés | MEDLINE | ID: mdl-36157832

RESUMEN

BACKGROUND: Children are a unique patient population. Anesthesia for pediatric abdominal surgery has long been achieved mainly with intravenous amiodarone and propofol alone or combined with other anesthetics. The incidence of complications and postoperative adverse reactions is relatively high owing to the imperfect development of various protocols for children. Choosing the most appropriate anesthesia program is an important means of reducing adverse reactions. AIM: To explore the clinical value of propofol combined with lidocaine-assisted anesthesia in pediatric surgery. METHODS: A total of 120 children who underwent abdominal surgery at our hospital from January 2016 to March 2018 were selected and divided into groups A and B using the random number table method, with 60 patients in each group. Group B received ketamine for anesthesia, while group A received ketamine, propofol, and lidocaine. The pre- and postoperative heart rate (HR); mean arterial pressure (MAP); arterial oxygen saturation (SpO2); serum adrenocorticotropic hormone (ACTH), interleukin-6 (IL-6), and cortisol (Cor) levels; restlessness score during the recovery period [Paediatric Anesthesia Emergence Delirium Scale (PAED)]; and adverse reactions were compared between the two groups. RESULTS: The HR, MAP, and SpO2 Level at five minutes before initiating anesthesia were compared between groups A and B, and the difference was not statistically significant (P > 0.05). At 10 and 20 minutes after anesthesia initiation, the HR and MAP were lower in group A compared with group B (P < 0.05). The differences in preoperative serum ACTH, IL-6, and Cor levels between groups A and B were not statistically significant (P > 0.05); however, the postoperative serum ACTH, IL-6, and Cor levels in group A were lower compared with group B (P < 0.05). Furthermore, the visual analog scale scores of group A at 2 h and 8 h postoperative were lower than those in group B, and the differences were statistically significant (P < 0.05). The mean PAED score in group A was lower than that in group B (P < 0.05), and the incidence of restlessness in group A was 23.33% lower than that in group B (36.67 %) (P < 0.05). The incidence of adverse reactions was lower in group A than in group B (6.25% vs 16.25%). CONCLUSION: The anesthetic effect of propofol combined with lidocaine and ketamine in pediatric surgery was better than that of ketamine alone, and had less influence on hemodynamics and pediatric stress response indices, lower incidence of restlessness in the recovery period, and lower incidence of adverse reactions.

13.
RSC Med Chem ; 13(7): 850-856, 2022 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-35923720

RESUMEN

Signalling through the adenosine receptors (ARs), in particular through the adenosine A2B receptor (A2BAR), has been shown to play a role in a variety of pathological conditions, ranging from immune disorders to cancer. Covalent ligands for the A2BAR have the potential to irreversibly block the receptor, as well as inhibit all A2BAR-induced signalling pathways. This will allow a thorough investigation of the pathophysiological role of the receptor. In this study, we synthesized and evaluated a set of potential covalent ligands for the A2BAR. The ligands all contain a core scaffold consisting of a substituted xanthine, varying in type and orientation of electrophilic group (warhead). Here, we find that the right combination of these variables is necessary for a high affinity, irreversible mode of binding and selectivity towards the A2BAR. Altogether, this is the case for sulfonyl fluoride 24 (LUF7982), a covalent ligand that allows for novel ways to interrogate the A2BAR.

14.
Molecules ; 27(15)2022 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-35897852

RESUMEN

The adenosine A2A receptor (A2AAR) is a class A G-protein-coupled receptor (GPCR). It is an immune checkpoint in the tumor micro-environment and has become an emerging target for cancer treatment. In this study, we aimed to explore the effects of cancer-patient-derived A2AAR mutations on ligand binding and receptor functions. The wild-type A2AAR and 15 mutants identified by Genomic Data Commons (GDC) in human cancers were expressed in HEK293T cells. Firstly, we found that the binding affinity for agonist NECA was decreased in six mutants but increased for the V275A mutant. Mutations A165V and A265V decreased the binding affinity for antagonist ZM241385. Secondly, we found that the potency of NECA (EC50) in an impedance-based cell-morphology assay was mostly correlated with the binding affinity for the different mutants. Moreover, S132L and H278N were found to shift the A2AAR towards the inactive state. Importantly, we found that ZM241385 could not inhibit the activation of V275A and P285L stimulated by NECA. Taken together, the cancer-associated mutations of A2AAR modulated ligand binding and receptor functions. This study provides fundamental insights into the structure-activity relationship of the A2AAR and provides insights for A2AAR-related personalized treatment in cancer.


Asunto(s)
Adenosina , Neoplasias , Adenosina/farmacología , Adenosina-5'-(N-etilcarboxamida) , Células HEK293 , Humanos , Ligandos , Mutación , Neoplasias/tratamiento farmacológico , Neoplasias/genética , Receptor de Adenosina A2A/genética , Receptor de Adenosina A2A/metabolismo , Microambiente Tumoral
15.
Front Pharmacol ; 13: 872335, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35677430

RESUMEN

Excitatory amino acid transporters (EAAT/SLC1) mediate Na+-dependent uptake of extracellular glutamate and are potential drug targets for neurological disorders. Conventional methods to assess glutamate transport in vitro are based on radiolabels, fluorescent dyes or electrophysiology, which potentially compromise the cell's physiology and are generally less suited for primary drug screens. Here, we describe a novel label-free method to assess human EAAT function in living cells, i.e., without the use of chemical modifications to the substrate or cellular environment. In adherent HEK293 cells overexpressing EAAT1, stimulation with glutamate or aspartate induced cell spreading, which was detected in real-time using an impedance-based biosensor. This change in cell morphology was prevented in the presence of the Na+/K+-ATPase inhibitor ouabain and EAAT inhibitors, which suggests the substrate-induced response was ion-dependent and transporter-specific. A mechanistic explanation for the phenotypic response was substantiated by actin cytoskeleton remodeling and changes in the intracellular levels of the osmolyte taurine, which suggests that the response involves cell swelling. In addition, substrate-induced cellular responses were observed for cells expressing other EAAT subtypes, as well as in a breast cancer cell line (MDA-MB-468) with endogenous EAAT1 expression. These findings allowed the development of a label-free high-throughput screening assay, which could be beneficial in early drug discovery for EAATs and holds potential for the study of other transport proteins that modulate cell shape.

16.
Molecules ; 27(7)2022 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-35408685

RESUMEN

The adenosine A3 receptor is a promising target for treating and diagnosing inflammation and cancer. In this paper, a series of bicyclo[3.1.0]hexane-based nucleosides was synthesized and evaluated for their P1 receptor affinities in radioligand binding studies. The study focused on modifications at 1-, 2-, and 6-positions of the purine ring and variations of the 5'-position at the bicyclo[3.1.0]hexane moiety, closing existing gaps in the structure-affinity relationships. The most potent derivative 30 displayed moderate A3AR affinity (Ki of 0.38 µM) and high A3R selectivity. A subset of compounds varied at 5'-position was further evaluated in functional P2Y1R assays, displaying no off-target activity.


Asunto(s)
Hexanos , Receptor de Adenosina A3 , Animales , Células CHO , Cricetinae , Ligandos , Nucleósidos/química , Ensayo de Unión Radioligante , Receptor de Adenosina A3/química , Relación Estructura-Actividad
17.
Hum Mol Genet ; 31(15): 2595-2605, 2022 08 17.
Artículo en Inglés | MEDLINE | ID: mdl-35288736

RESUMEN

Prior studies have shown that genetic factors play important roles in ovarian endometriosis. Herein, we first analyzed the whole-exome sequencing data from 158 patients with ovarian endometriosis and 385 local control women without endometriosis. Among which, a rare missense variant in the MMP7 (p.I79T, rs150338402) gene exhibited a significant frequency difference. This rare variant was screened in an additional 1176 patients and 600 control women via direct DNA sequencing. Meanwhile, a total of 38 available clinical characteristics were collected. Our results showed 45 out of 1334 (3.37%) patients, while 15 out of 985 control women (1.52%) (P = 0.0076) harbored this rare variant, respectively. This rare variant was associated with clinical features such as follicle-stimulating hormone (Padj = 0.0342), luteinizing hormone (Padj = 0.0038), progesterone (Padj = 1.4e-7), testosterone (Padj = 0.0923), total bilirubin (Padj = 0.0699), carcinoembryonic antigen (Padj = 0.0665) and squamous cell carcinoma antigen (Padj = 0.0817), respectively. Functional assays showed that this rare variant could promote cell migration, invasion, epithelial-mesenchymal transition (EMT) and increase the proteolytic protein activity of MMP7, implicating that the increased capacities of cell invasion, migration and EMT might be mediated by enhanced proteolytic activity of MMP7 mutant. These results showed that the MMP7 rare missense variant (p.I79T) played important roles in the pathogenesis of ovarian endometriosis. In conclusion, we identified, for the first time, a significantly enriched MMP7 rare variant in ovarian endometriosis; this rare variant was closely associated with certain clinical features in ovarian endometriosis; thus, it could be a promising early diagnostic biomarker for this disease.


Asunto(s)
Endometriosis , Metaloproteinasa 7 de la Matriz/genética , Neoplasias Ováricas , Endometriosis/genética , Transición Epitelial-Mesenquimal , Femenino , Humanos , Metaloproteinasa 7 de la Matriz/metabolismo , Mutación Missense/genética , Neoplasias Ováricas/patología , Secuenciación del Exoma
18.
JACS Au ; 1(4): 380-395, 2021 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-34056633

RESUMEN

In this work, a pair of gold(III) complexes derived from the analogous tetrapyridyl ligands H2biqbpy1 and H2biqbpy2 was prepared: the rollover, bis-cyclometalated [Au(biqbpy1)Cl ([1]Cl) and its isomer [Au(biqbpy2)Cl ([2]Cl). In [1]+, two pyridyl rings coordinate to the metal via a Au-C bond (C∧N∧N∧C coordination) and the two noncoordinated amine bridges of the ligand remain protonated, while in [2]+ all four pyridyl rings of the ligand coordinate to the metal via a Au-N bond (N∧N∧N∧N coordination), but both amine bridges are deprotonated. As a result, both complexes are monocationic, which allowed comparison of the sole effect of cyclometalation on the chemistry, protein interaction, and anticancer properties of the gold(III) compounds. Due to their identical monocationic charge and similar molecular shape, both complexes [1]Cl and [2]Cl displaced reference radioligand [3H]dofetilide equally well from cell membranes expressing the Kv11.1 (hERG) potassium channel, and more so than the tetrapyridyl ligands H2biqbpy1 and H2biqbpy2. By contrast, cyclometalation rendered [1]Cl coordinatively stable in the presence of biological thiols, while [2]Cl was reduced by a millimolar concentration of glutathione into metastable Au(I) species releasing the free ligand H2biqbpy2 and TrxR-inhibiting Au+ ions. The redox stability of [1]Cl dramatically decreased its thioredoxin reductase (TrxR) inhibition properties, compared to [2]Cl. On the other hand, unlike [2]Cl, [1]Cl aggregated into nanoparticles in FCS-containing medium, which resulted in much more efficient gold cellular uptake. [1]Cl had much more selective anticancer properties than [2]Cl and cisplatin, as it was almost 10 times more cytotoxic to human cancer cells (A549, A431, A375, and MCF7) than to noncancerous cells (MRC5). Mechanistic studies highlight the strikingly different mode of action of the two compounds: while for [1]Cl high gold cellular uptake, nuclear DNA damage, and interaction with hERG may contribute to cell killing, for [2]Cl extracellular reduction released TrxR-inhibiting Au+ ions that were taken up in minute amounts in the cytosol, and a toxic tetrapyridyl ligand also capable of binding to hERG. These results demonstrate that bis-cyclometalation is an appealing method to improve the redox stability of Au(III) compounds and to develop gold-based cytotoxic compounds that do not rely on TrxR inhibition to kill cancer cells.

19.
J Med Chem ; 64(7): 3827-3842, 2021 04 08.
Artículo en Inglés | MEDLINE | ID: mdl-33764785

RESUMEN

In this study, we determined the crystal structure of an engineered human adenosine A2A receptor bound to a partial agonist and compared it to structures cocrystallized with either a full agonist or an antagonist/inverse agonist. The interaction between the partial agonist, belonging to a class of dicyanopyridines, and amino acids in the ligand binding pocket inspired us to develop a small library of derivatives and assess their affinity in radioligand binding studies and potency and intrinsic activity in a functional, label-free, intact cell assay. It appeared that some of the derivatives retained the partial agonist profile, whereas other ligands turned into inverse agonists. We rationalized this remarkable behavior with additional computational docking studies.


Asunto(s)
Agonistas del Receptor de Adenosina A2/metabolismo , Aminopiridinas/metabolismo , Pirimidinas/metabolismo , Receptor de Adenosina A2A/metabolismo , Aminopiridinas/síntesis química , Animales , Sitios de Unión , Células CHO , Cricetulus , Cristalografía por Rayos X , Agonismo Inverso de Drogas , Agonismo Parcial de Drogas , Células HEK293 , Humanos , Ligandos , Simulación del Acoplamiento Molecular , Unión Proteica , Pirimidinas/síntesis química , Bibliotecas de Moléculas Pequeñas/metabolismo
20.
J Asian Nat Prod Res ; 23(1): 39-54, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31833411

RESUMEN

Chrysin amino acid derivatives were synthesized to evaluate for their antiproliferative activities. Among them, N-(7-((5-hydroxy-4-oxo-2-phenyl-4H-chromen-7-yl)oxy)valeryl)-L-leucine (8c) displayed the most remarkable inhibitory activities against MCF-7 cells with IC50 values of 16.6 µM. Preliminary mechanistic studies showed that 8c could inhibit the colony formation and migration of MCF-7 cells. Flow cytometry analysis demonstrated that 8c mediated cell apoptosis and the prolongation of cell cycle progression in G1/S-phase against MCF-7 cells. Besides, 8c displayed the moderate inhibition against EGFR. Western blot assay suggested that 8c significantly inhibited EGFR phosphorylation. Molecular docking showed that 8c can bind the EGFR kinase well.


Asunto(s)
Antineoplásicos , Aminoácidos/farmacología , Antineoplásicos/farmacología , Apoptosis , Línea Celular Tumoral , Proliferación Celular , Regulación hacia Abajo , Diseño de Fármacos , Ensayos de Selección de Medicamentos Antitumorales , Receptores ErbB/metabolismo , Receptores ErbB/farmacología , Flavonoides , Humanos , Simulación del Acoplamiento Molecular , Estructura Molecular , Relación Estructura-Actividad
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