Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 3.178
Filtrar
1.
Bull Environ Contam Toxicol ; 105(4): 595-601, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32862252

RESUMO

The residual characteristics and risk assessment with respect to cyazofamid and its metabolite 4-chloro-5-p-tolylimidazole-2-carbonitrile were monitored in case of Korean cabbage at different preharvest intervals during a greenhouse trial. The 0.02 kg a.i/ha of cyazofamid was sprayed twice on seven-day intervals (i.e., on day 0, 7, 14, and 21 before harvest). The liquid chromatography-tandem mass spectrometry analysis was used to monitor the residual amount of fungicide. The matrix-matched calibration curves with respect to the cyazofamid in Korean cabbage exhibited good linearity (R2 ≥ 0.999) and acceptable recoveries of 84.1%-114.9%. The biological half-life of cyazofamid in Korean cabbage was 3.18 days. During the treatment, the preharvest residue of cyazofamid in Korean cabbage 14 days before harvest (0.80 mg/kg) was lower than that specified by the MFDS-MRL (Ministry of Food and Drug Safety-Maximum Residue Limit, 2.0 mg/kg) and should be recommended as the safe preharvest-interval application limit. The hazard quotient showed low toxicity (70.58%) during the risk assessment study of cyazofamid.


Assuntos
Fungicidas Industriais/toxicidade , Imidazóis/toxicidade , Resíduos de Praguicidas/toxicidade , Sulfonamidas/toxicidade , Brassica/química , Cromatografia Líquida/métodos , Fungicidas Industriais/química , Fungicidas Industriais/metabolismo , Meia-Vida , Imidazóis/metabolismo , Resíduos de Praguicidas/análise , Resíduos de Praguicidas/metabolismo , República da Coreia , Medição de Risco , Sulfonamidas/metabolismo
2.
Chemosphere ; 261: 127756, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32731027

RESUMO

Urgent need for treatments limit studies of therapeutic drugs before approval by regulatory agencies. Analyses of drugs after approval can therefore improve our understanding of their mechanism of action and enable better therapies. We screened a library of 1443 Food and Drug Administration (FDA)-approved drugs using a simple assay in the nematode C. elegans and found three compounds that caused morphological changes. While the anticoagulant ticlopidine and the antifungal sertaconazole caused both accumulations that resulted in distinct distortions of pharyngeal anatomy and lethality upon acute exposure, the proton-pump inhibitor dexlansoprazole caused molting defects and required exposure during larval development. Such easily detectable defects in a powerful genetic model system advocate the continued exploration of current medicines using a variety of model organisms to better understand drugs already prescribed to millions of patients.


Assuntos
Bioacumulação/efeitos dos fármacos , Caenorhabditis elegans/efeitos dos fármacos , Dexlansoprazol/toxicidade , Imidazóis/toxicidade , Muda/efeitos dos fármacos , Tiofenos/toxicidade , Ticlopidina/toxicidade , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Caenorhabditis elegans/metabolismo , Dexlansoprazol/metabolismo , Aprovação de Drogas , Epigênese Genética/efeitos dos fármacos , Humanos , Imidazóis/metabolismo , Larva/efeitos dos fármacos , Larva/genética , Larva/crescimento & desenvolvimento , Larva/metabolismo , Mutação , Tiofenos/metabolismo , Ticlopidina/metabolismo , Estados Unidos , United States Food and Drug Administration
3.
Chemosphere ; 259: 127490, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32650166

RESUMO

Insect resistance to chemical insecticide is a global problem that presents an ongoing threat to sustainable agriculture. Although the increased production of detoxification enzymes has been frequently implicated in resistance development, the mechanisms employed by insecticide-resistant insects for overexpression of these genes remain elusive. Here we report that neuropeptide adipokinetic hormone (AKH) negatively regulates the expression of CYP6ER1 and CYP6AY1, two important cytochrome P450 monooxygenases (P450s) that confer resistance to neonicotinoid imidacloprid in the brown planthopper (BPH). Imidacloprid exposure suppresses AKH synthesis in the susceptible BPH, and AKH is inhibited in the imidacloprid-resistant strain. RNA interference (RNAi) and AKH peptide injection revealed that imidacloprid exposure inhibits the AKH signaling cascade and then provokes reactive oxygen species (ROS) burst. These in turn activate the transcription factors cap 'n' collar isoform-C (CncC) and muscle aponeurosis fibromatosis (MafK). RNAi and ROS scavenger assays showed that ROS induces CYP6ER1 expression by activating CncC and MafK, while ROS mediates induction of CYP6AY1 through another unidentified pathway in the resistant BPH. Collectively, these results provide new insights into the regulation of insecticide resistance and implicate both the neuropeptide AKH-mediated ROS burst and transcription factors are involved in the overexpression of P450 detoxification genes in insecticide-resistant insects.


Assuntos
Sistema Enzimático do Citocromo P-450/metabolismo , Hemípteros/química , Hormônios de Inseto/fisiologia , Resistência a Inseticidas/efeitos dos fármacos , Neonicotinoides/farmacologia , Nitrocompostos/farmacologia , Oligopeptídeos/fisiologia , Ácido Pirrolidonocarboxílico/análogos & derivados , Animais , Família 6 do Citocromo P450/metabolismo , Hemípteros/fisiologia , Imidazóis/metabolismo , Resistência a Inseticidas/genética , Inseticidas/farmacologia , Interferência de RNA , Espécies Reativas de Oxigênio/metabolismo , Fatores de Transcrição/fisiologia
4.
Proc Natl Acad Sci U S A ; 117(30): 17808-17819, 2020 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-32661168

RESUMO

p53 is the most frequently mutated, well-studied tumor-suppressor gene, yet the molecular basis of the switch from p53-induced cell-cycle arrest to apoptosis remains poorly understood. Using a combination of transcriptomics and functional genomics, we unexpectedly identified a nodal role for the caspase-8 paralog and only human pseudo-caspase, FLIP(L), in regulating this switch. Moreover, we identify FLIP(L) as a direct p53 transcriptional target gene that is rapidly up-regulated in response to Nutlin-3A, an MDM2 inhibitor that potently activates p53. Genetically or pharmacologically inhibiting expression of FLIP(L) using siRNA or entinostat (a clinically relevant class-I HDAC inhibitor) efficiently promoted apoptosis in colorectal cancer cells in response to Nutlin-3A, which otherwise predominantly induced cell-cycle arrest. Enhanced apoptosis was also observed when entinostat was combined with clinically relevant, p53-activating chemotherapy in vitro, and this translated into enhanced in vivo efficacy. Mechanistically, FLIP(L) inhibited p53-induced apoptosis by blocking activation of caspase-8 by the TRAIL-R2/DR5 death receptor; notably, this activation was not dependent on receptor engagement by its ligand, TRAIL. In the absence of caspase-8, another of its paralogs, caspase-10 (also transcriptionally up-regulated by p53), induced apoptosis in Nutlin-3A-treated, FLIP(L)-depleted cells, albeit to a lesser extent than in caspase-8-proficient cells. FLIP(L) depletion also modulated transcription of canonical p53 target genes, suppressing p53-induced expression of the cell-cycle regulator p21 and enhancing p53-induced up-regulation of proapoptotic PUMA. Thus, even in the absence of caspase-8/10, FLIP(L) silencing promoted p53-induced apoptosis by enhancing PUMA expression. Thus, we report unexpected, therapeutically relevant roles for FLIP(L) in determining cell fate following p53 activation.


Assuntos
Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Acetilação , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/genética , Benzamidas/farmacologia , Caspase 8/metabolismo , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/genética , Linhagem Celular Tumoral , Sinergismo Farmacológico , Regulação da Expressão Gênica , Humanos , Imidazóis/metabolismo , Modelos Biológicos , Piperazinas/metabolismo , Ligação Proteica , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Piridinas/farmacologia , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Proteína Supressora de Tumor p53/genética
5.
Nucleic Acids Res ; 48(13): 7052-7065, 2020 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-32544249

RESUMO

Oligonucleotide-based therapeutics have become a reality, and are set to transform management of many diseases. Nevertheless, the modulatory activities of these molecules on immune responses remain incompletely defined. Here, we show that gene targeting 2'-O-methyl (2'OMe) gapmer antisense oligonucleotides (ASOs) can have opposing activities on Toll-Like Receptors 7 and 8 (TLR7/8), leading to divergent suppression of TLR7 and activation of TLR8, in a sequence-dependent manner. Surprisingly, TLR8 potentiation by the gapmer ASOs was blunted by locked nucleic acid (LNA) and 2'-methoxyethyl (2'MOE) modifications. Through a screen of 192 2'OMe ASOs and sequence mutants, we characterized the structural and sequence determinants of these activities. Importantly, we identified core motifs preventing the immunosuppressive activities of 2'OMe ASOs on TLR7. Based on these observations, we designed oligonucleotides strongly potentiating TLR8 sensing of Resiquimod, which preserve TLR7 function, and promote strong activation of phagocytes and immune cells. We also provide proof-of-principle data that gene-targeting ASOs can be selected to synergize with TLR8 agonists currently under investigation as immunotherapies, and show that rational ASO selection can be used to prevent unintended immune suppression of TLR7. Taken together, our work characterizes the immumodulatory effects of ASOs to advance their therapeutic development.


Assuntos
Oligodesoxirribonucleotídeos Antissenso/farmacologia , Receptor 7 Toll-Like/metabolismo , Receptor 8 Toll-Like/metabolismo , Células Cultivadas , Humanos , Imidazóis/metabolismo , Leucócitos Mononucleares , Oligonucleotídeos/metabolismo , Receptor 7 Toll-Like/agonistas , Receptor 8 Toll-Like/agonistas
6.
J Med Chem ; 63(9): 4603-4616, 2020 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-32223240

RESUMO

Glioblastoma multiforme (GBM) is the deadliest form of brain tumor. It is known for its ability to escape the therapeutic options available to date thanks to the presence of a subset of cells endowed with stem-like properties and ability to resist to cytotoxic treatments. As the cytosolic enzyme aldehyde dehydrogenase 1A3 turns out to be overexpressed in these kinds of cells, playing a key role for their vitality, treatments targeting this enzyme may represent a successful strategy to fight GBM. In this work, we describe a novel class of imidazo[1,2-a]pyridine derivatives as aldehyde dehydrogenase 1A3 inhibitors, reporting the evidence of their significance as novel drug candidates for the treatment of GBM. Besides showing an interesting functional profile, in terms of activity against the target enzyme and selectivity toward highly homologous isoenzymes, representative examples of the series also showed a nanomolar to picomolar efficacy against patient-derived GBM stem-like cells, thus proving the concept that targeting aldehyde dehydrogenase might represent a novel and promising way to combat GBM by striking its ability to divide immortally.


Assuntos
Aldeído Oxirredutases/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Imidazóis/farmacologia , Células-Tronco Neoplásicas/efeitos dos fármacos , Piridinas/farmacologia , Aldeído Oxirredutases/química , Aldeído Oxirredutases/metabolismo , Domínio Catalítico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/metabolismo , Glioblastoma/tratamento farmacológico , Humanos , Imidazóis/síntese química , Imidazóis/metabolismo , Simulação de Acoplamento Molecular , Estrutura Molecular , Ligação Proteica , Piridinas/síntese química , Piridinas/metabolismo , Relação Estrutura-Atividade
7.
J Med Chem ; 63(8): 4293-4305, 2020 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-32243152

RESUMO

Acquired drug resistance in epidermal growth factor receptor (EGFR) mutant non-small-cell lung cancer is a persistent challenge in cancer therapy. Previous studies of trisubstituted imidazole inhibitors led to the serendipitous discovery of inhibitors that target the drug resistant EGFR(L858R/T790M/C797S) mutant with nanomolar potencies in a reversible binding mechanism. To dissect the molecular basis for their activity, we determined the binding modes of several trisubstituted imidazole inhibitors in complex with the EGFR kinase domain with X-ray crystallography. These structures reveal that the imidazole core acts as an H-bond acceptor for the catalytic lysine (K745) in the "αC-helix out" inactive state. Selective N-methylation of the H-bond accepting nitrogen ablates inhibitor potency, confirming the role of the K745 H-bond in potent, noncovalent inhibition of the C797S variant. Insights from these studies offer new strategies for developing next generation inhibitors targeting EGFR in non-small-cell lung cancer.


Assuntos
Antineoplásicos/química , Variação Genética/genética , Imidazóis/antagonistas & inibidores , Mutação/genética , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/metabolismo , Cristalografia por Raios X , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/genética , Receptores ErbB/metabolismo , Variação Genética/efeitos dos fármacos , Imidazóis/metabolismo , Mutação/efeitos dos fármacos , Estrutura Secundária de Proteína , Células Sf9
8.
Proc Natl Acad Sci U S A ; 117(11): 5741-5748, 2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-32123094

RESUMO

The hypothesized central role of RNA in the origin of life suggests that RNA propagation predated the advent of complex protein enzymes. A critical step of RNA replication is the template-directed synthesis of a complementary strand. Two experimental approaches have been extensively explored in the pursuit of demonstrating protein-free RNA synthesis: template-directed nonenzymatic RNA polymerization using intrinsically reactive monomers and ribozyme-catalyzed polymerization using more stable substrates such as biological 5'-triphosphates. Despite significant progress in both approaches in recent years, the assembly and copying of functional RNA sequences under prebiotic conditions remains a challenge. Here, we explore an alternative approach to RNA-templated RNA copying that combines ribozyme catalysis with RNA substrates activated with a prebiotically plausible leaving group, 2-aminoimidazole (2AI). We applied in vitro selection to identify ligase ribozymes that catalyze phosphodiester bond formation between a template-bound primer and a phosphor-imidazolide-activated oligomer. Sequencing revealed the progressive enrichment of 10 abundant sequences from a random sequence pool. Ligase activity was detected in all 10 RNA sequences; all required activation of the ligator with 2AI and generated a 3'-5' phosphodiester bond. We propose that ribozyme catalysis of phosphodiester bond formation using intrinsically reactive RNA substrates, such as imidazolides, could have been an evolutionary step connecting purely nonenzymatic to ribozyme-catalyzed RNA template copying during the origin of life.


Assuntos
Imidazóis/química , Origem da Vida , RNA Ligase (ATP)/química , RNA Catalítico/química , Imidazóis/metabolismo , Polimerização , RNA Ligase (ATP)/metabolismo , RNA Catalítico/metabolismo
9.
Appl Environ Microbiol ; 86(11)2020 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-32220843

RESUMO

Microbial production of the neurotoxin methylmercury (MeHg) is a significant health and environmental concern, as it can bioaccumulate and biomagnify in the food web. A chalkophore or a copper-binding compound, termed methanobactin (MB), has been shown to form strong complexes with mercury [as Hg(II)] and also enables some methanotrophs to degrade MeHg. It is unknown, however, if Hg(II) binding with MB can also impede Hg(II) methylation by other microbes. Contrary to expectations, MB produced by the methanotroph Methylosinus trichosporium OB3b (OB3b-MB) enhanced the rate and efficiency of Hg(II) methylation more than that observed with thiol compounds (such as cysteine) by the mercury-methylating bacteria Desulfovibrio desulfuricans ND132 and Geobacter sulfurreducens PCA. Compared to no-MB controls, OB3b-MB decreased the rates of Hg(II) sorption and internalization, but increased methylation by 5- to 7-fold, suggesting that Hg(II) complexation with OB3b-MB facilitated exchange and internal transfer of Hg(II) to the HgcAB proteins required for methylation. Conversely, addition of excess amounts of OB3b-MB or a different form of MB from Methylocystis strain SB2 (SB2-MB) inhibited Hg(II) methylation, likely due to greater binding of Hg(II). Collectively, our results underscore the complex roles of microbial exogenous metal-scavenging compounds in controlling net production and bioaccumulation of MeHg in the environment.IMPORTANCE Some anaerobic microorganisms convert inorganic mercury (Hg) into the neurotoxin methylmercury, which can bioaccumulate and biomagnify in the food web. While the genetic basis of microbial mercury methylation is known, factors that control net methylmercury production in the environment are still poorly understood. Here, it is shown that mercury methylation can be substantially enhanced by one form of an exogenous copper-binding compound (methanobactin) produced by some methanotrophs, but not by another. This novel finding illustrates that complex interactions exist between microbes and that these interactions can potentially affect the net production of methylmercury in situ.


Assuntos
Desulfovibrio desulfuricans/metabolismo , Poluentes Ambientais/metabolismo , Geobacter/metabolismo , Imidazóis/metabolismo , Mercúrio/metabolismo , Methylosinus trichosporium/metabolismo , Oligopeptídeos/metabolismo , Metilação
10.
J Chromatogr A ; 1620: 461003, 2020 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-32156458

RESUMO

The enormous growth in drug discovery paradigm has necessitated continuous exploration of new methods for drug-protein interaction analysis. To enhance the role of these methodologies in designing rational drugs, this work extended an immobilized angiotensin II type I receptor (AT1R) based affinity chromatography in antihypertensive compound identification. We fused haloalkane dehalogenase at C-terminus of AT1R and expressed the fusion receptor in E. coli. The expressed receptor was covalently immobilized onto 8.0 µm microspheres by mixing the cell lysate with 6-chlorocaproic acid-modified amino polystyrene microspheres. The immobilized AT1R was utilized for thermodynamic and kinetic interaction analysis between the receptor and four specific ligands. Following confirmation of these interactions by molecular docking, we identified puerarin and rosmarinic acid by determining their binding to the receptor. Azilsartan, candesartan, valsartan and olmesartan displayed two kinds of binding sites to AT1R by injection amount-dependent method. By molecular docking, we recognize the driving forces of the interaction as electrostatic interaction, hydrogen bonds and van der Waals force. The dissociation rate constants (kd) of azilsartan, candesartan, valsartan and olmesartan to AT1R were 0.01138 ± 0.003, 0.05142 ± 0.003, 0.07547 ± 0.004 and 0.01310 ± 0.005 min-1 by peak profiling assay. Comparing with these parameters, puerarin and rosmarinic acid presented lower affinity (KA: 0.12 × 104 and 1.5 × 104/M) and slower kinetics (kd: 0.6864 ± 0.03 and 0.3005 ± 0.01 min-1) to the receptor. These results, taking together, indicated that the immobilized AT1R has the capacity to probe antihypertensive compounds.


Assuntos
Anti-Hipertensivos/metabolismo , Ensaios de Triagem em Larga Escala/métodos , Receptor Tipo 1 de Angiotensina/metabolismo , Anti-Hipertensivos/química , Benzimidazóis/química , Benzimidazóis/metabolismo , Sítios de Ligação , Cromatografia de Afinidade , Cinamatos/metabolismo , Depsídeos/metabolismo , Imidazóis/química , Imidazóis/metabolismo , Proteínas Imobilizadas/química , Proteínas Imobilizadas/metabolismo , Isoflavonas/metabolismo , Cinética , Ligantes , Simulação de Acoplamento Molecular , Oxidiazóis/química , Oxidiazóis/metabolismo , Receptor Tipo 1 de Angiotensina/química , Receptor Tipo 1 de Angiotensina/genética , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/metabolismo , Tetrazóis/química , Tetrazóis/metabolismo , Termodinâmica , Valsartana/química , Valsartana/metabolismo
11.
J Med Chem ; 63(7): 3538-3551, 2020 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-32134266

RESUMO

The overaccumulation of glycogen appears as a hallmark in various glycogen storage diseases (GSDs), including Pompe, Cori, Andersen, and Lafora disease. Accumulating evidence suggests that suppression of glycogen accumulation represents a potential therapeutic approach for treating these GSDs. Using a fluorescence polarization assay designed to screen for inhibitors of the key glycogen synthetic enzyme, glycogen synthase (GS), we identified a substituted imidazole, (rac)-2-methoxy-4-(1-(2-(1-methylpyrrolidin-2-yl)ethyl)-4-phenyl-1H-imidazol-5-yl)phenol (H23), as a first-in-class inhibitor for yeast GS 2 (yGsy2p). Data from X-ray crystallography at 2.85 Å, as well as kinetic data, revealed that H23 bound within the uridine diphosphate glucose binding pocket of yGsy2p. The high conservation of residues between human and yeast GS in direct contact with H23 informed the development of around 500 H23 analogs. These analogs produced a structure-activity relationship profile that led to the identification of a substituted pyrazole, 4-(4-(4-hydroxyphenyl)-3-(trifluoromethyl)-1H-pyrazol-5-yl)pyrogallol, with a 300-fold improved potency against human GS. These substituted pyrazoles possess a promising scaffold for drug development efforts targeting GS activity in GSDs associated with excess glycogen accumulation.


Assuntos
Inibidores Enzimáticos/química , Glicogênio Sintase/antagonistas & inibidores , Imidazóis/química , Pirazóis/química , Animais , Caenorhabditis elegans/enzimologia , Cristalografia por Raios X , Descoberta de Drogas , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/metabolismo , Glicogênio Sintase/química , Glicogênio Sintase/metabolismo , Células HEK293 , Humanos , Imidazóis/síntese química , Imidazóis/metabolismo , Cinética , Estrutura Molecular , Ligação Proteica , Pirazóis/síntese química , Pirazóis/metabolismo , Saccharomyces cerevisiae/enzimologia , Relação Estrutura-Atividade
12.
J Med Chem ; 63(7): 3610-3633, 2020 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-32150414

RESUMO

Imidazoline I2 receptors (I2-IR), widely distributed in the CNS and altered in patients that suffer from neurodegenerative disorders, are orphans from a structural point of view, and new I2-IR ligands are urgently required for improving their pharmacological characterization. We report the synthesis and three-dimensional quantitative structure-activity relationship (3D-QSAR) studies of a new family of bicyclic α-iminophosphonates endowed with relevant affinities for human brain I2-IR. Acute treatment in mice with a selected compound significantly decreased Fas-associated protein with death domain (FADD) in the hippocampus, a key signaling mediator of neuroprotective actions. Additionally, in vivo studies in the familial Alzheimer's disease 5xFAD murine model revealed beneficial effects in behavior and cognition. These results are supported by changes in molecular pathways related to cognitive decline and Alzheimer's disease. Therefore, bicyclic α-iminophosphonates are tools that may open new therapeutic avenues for I2-IR, particularly for unmet neurodegenerative conditions.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Imidazóis/uso terapêutico , Receptores de Imidazolinas/metabolismo , Nootrópicos/uso terapêutico , Organofosfonatos/uso terapêutico , Animais , Chlorocebus aethiops , Reação de Cicloadição , Cães , Feminino , Células HeLa , Hipocampo/efeitos dos fármacos , Humanos , Imidazóis/síntese química , Imidazóis/metabolismo , Imidazóis/farmacocinética , Ligantes , Células Madin Darby de Rim Canino , Camundongos , Estrutura Molecular , Nootrópicos/síntese química , Nootrópicos/metabolismo , Nootrópicos/farmacocinética , Organofosfonatos/síntese química , Organofosfonatos/metabolismo , Organofosfonatos/farmacocinética , Relação Quantitativa Estrutura-Atividade , Células Vero
13.
J Med Chem ; 63(6): 3188-3204, 2020 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-32134652

RESUMO

Autotaxin (ATX, also known as ENPP2) is a predominant lysophosphatidic acid (LPA)-producing enzyme in the body, and LPA regulates various physiological functions, such as angiogenesis and wound healing, as well as pathological functions, including proliferation, metastasis, and fibrosis, via specific LPA receptors. Therefore, the ATX-LPA axis is a promising therapeutic target for dozens of diseases, including cancers, pulmonary and liver fibroses, and neuropathic pain. Previous structural studies revealed that the catalytic domain of ATX has a hydrophobic pocket and a hydrophobic channel; these serve to recognize the substrate, lysophosphatidylcholine (LPC), and deliver generated LPA to LPA receptors on the plasma membrane. Most reported ATX inhibitors bind to either the hydrophobic pocket or the hydrophobic channel. Herein, we present a unique ATX inhibitor that binds mainly to the hydrophobic pocket and also partly to the hydrophobic channel, inhibiting ATX activity with high potency and selectivity in vitro and in vivo. Notably, our inhibitor can rescue the cardia bifida (two hearts) phenotype in ATX-overexpressing zebrafish embryos.


Assuntos
Imidazóis/uso terapêutico , Inibidores de Fosfodiesterase/uso terapêutico , Diester Fosfórico Hidrolases/metabolismo , Pirimidinas/uso terapêutico , Animais , Domínio Catalítico , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Cristalografia por Raios X , Cardiopatias/prevenção & controle , Humanos , Interações Hidrofóbicas e Hidrofílicas , Imidazóis/síntese química , Imidazóis/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Estrutura Molecular , Inibidores de Fosfodiesterase/síntese química , Inibidores de Fosfodiesterase/metabolismo , Ligação Proteica , Pirimidinas/síntese química , Pirimidinas/metabolismo , Relação Estrutura-Atividade , Peixe-Zebra
14.
Chemosphere ; 249: 126167, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32062203

RESUMO

Honeydew production is a characteristic of soft scales and other hemipteran insects. Honeydew has the capacity to alter the ecology of predators and parasitoids because it is used as a food resource and can contain insecticidal proteins from hemipteran host plants. We examined honeydew excreted by the striped pine scale (Hemiptera: Coccidae), Toumeyella pini (King), after feeding on pine trees treated with systemic insecticides to determine whether they could eliminate insecticidal compounds in honeydew. Imidacloprid and spirotetramat were applied at labeled rates to soil or foliage. Water sensitive paper was used to measure honeydew production and liquid chromatography coupled to mass spectrometry (LC-MS) to analyze excreted insecticide concentrations. Foliar and soil applications of imidacloprid caused a 25-fold reduction honeydew produced by scales six days after treatment (DAT). In contrast, spirotetramat treatments did not affect honeydew production. Parent compounds of both insecticides were detected in honeydew. However, on imidacloprid treated plants, these compounds were detected at similar concentrations in honeydew collected at 4 DAT from soil and foliar treatments. Imidacloprid was only detected from soil treatments at 8 DAT. Similarly, the spirotetramat parent compound was found 4 DAT after soil and foliar treatments, but only at 8 DAT in foliar treatments. At this time the concentration of spirotetramat in honeydew was six-fold higher than at 4 DAT. We conclude that striped pine scales excrete insecticides in honeydew even when the toxicant greatly reduces honeydew production. Honeydew excretion is thus a mechanism of bioaccumulation and has the potential to harm honeydew-feeding organisms.


Assuntos
Hemípteros/metabolismo , Inseticidas/metabolismo , Animais , Compostos Aza , Imidazóis/análise , Imidazóis/metabolismo , Insetos , Inseticidas/análise , Neonicotinoides/metabolismo , Nitrocompostos/metabolismo , Pinus , Solo , Compostos de Espiro
15.
Sci Rep ; 10(1): 1049, 2020 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-31974452

RESUMO

Pifithrin-α (PFT-α) is a small molecule which has been widely used as a specific inhibitor of p53 transcription activity. However, its molecular mechanism of action remains unclear. PFT-α has also been described to display potent p53-independent activity in cells. In this study, we addressed the mechanism of action of PFT-α. We found that PFT-α failed to prevent the effects of Mdm2 inhibitor Nutlin-3 on cell cycle and apoptosis in several cancer cell lines. However, PFT-α rescued normal primary fibroblasts from growth inhibition by Nutlin-3. PFT-α displayed a very limited effect on p53-dependent transcription upon its activation by Nutlin-3. Moreover, PFT-α inhibitory effect on transcription was highly dependent on the nature of the p53 target gene. PFT-α attenuated post-translational modifications of p53 without affecting total p53 protein level. Finally, we found that PFT-α can decrease the level of intracellular reactive oxygen species through activation of an aryl hydrocarbon receptor (AHR)-Nrf2 axis in a p53-independent manner. In conclusion, PFT-α inhibits only some aspects of p53 function, therefore it should be used with extreme caution to study p53-dependent processes.


Assuntos
Benzotiazóis/farmacologia , Imidazóis/metabolismo , Piperazinas/metabolismo , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Tolueno/análogos & derivados , Transcrição Genética/efeitos dos fármacos , Proteína Supressora de Tumor p53/antagonistas & inibidores , Apoptose/efeitos dos fármacos , Fatores de Transcrição Hélice-Alça-Hélice Básicos/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Células HCT116 , Humanos , Células MCF-7 , Fator 2 Relacionado a NF-E2/efeitos dos fármacos , Processamento de Proteína Pós-Traducional/genética , Proteínas Proto-Oncogênicas c-mdm2/antagonistas & inibidores , Interferência de RNA , RNA Interferente Pequeno/genética , Espécies Reativas de Oxigênio/metabolismo , Receptores de Hidrocarboneto Arílico/efeitos dos fármacos , Tolueno/farmacologia , Transcrição Genética/genética , Proteína Supressora de Tumor p53/metabolismo
16.
J Med Chem ; 63(3): 1233-1244, 2020 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-31939669

RESUMO

Human hand, foot, and mouth disease (HFMD) is a serious public health threat with high infection rates in children and infants who reside in Asia and the Pacific regions, and no effective drugs are currently available. Enterovirus 71 (EV71) and coxsackievirus A16 are the major etiological pathogens. Based on an essential hydrophobic pocket on the viral capsid protein VP1, we designed and synthesized a series of small molecular weight compounds as inhibitors of EV71. A potential drug candidate named NLD-22 exhibited excellent antiviral activity (with an EC50 of 5.056 nM and a 100% protection rate for mice at a dose of 20 mg/kg) and low toxicity. NLD-22 had a favorable pharmacokinetic profile. High-resolution cryo-electron microscopy structural analysis confirmed NLD-22 bound to the hydrophobic pocket in VP1 to block viral infection. In general, NLD-22 was indicated to be a promising potential drug candidate for the treatment of HFMD.


Assuntos
Antivirais/uso terapêutico , Enterovirus Humano A/efeitos dos fármacos , Doença de Mão, Pé e Boca/tratamento farmacológico , Imidazóis/uso terapêutico , Animais , Antivirais/síntese química , Antivirais/metabolismo , Antivirais/farmacocinética , Sítios de Ligação , Proteínas do Capsídeo/química , Proteínas do Capsídeo/metabolismo , Desenho de Fármacos , Enterovirus Humano A/química , Feminino , Imidazóis/síntese química , Imidazóis/metabolismo , Imidazóis/farmacocinética , Cristalino/patologia , Masculino , Camundongos Endogâmicos BALB C , Microssomos Hepáticos/metabolismo , Ligação Proteica , Ratos Sprague-Dawley , Peixe-Zebra
17.
J Med Chem ; 63(4): 1642-1659, 2020 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-31961685

RESUMO

Indoleamine 2,3-dioxygenase (IDO1) inhibitors are speculated to be useful in cancer immunotherapy, but a phase III clinical trial of the most advanced IDO1 inhibitor, epacadostat, did not meet its primary end point and was abandoned. In previous work, we identified the novel IDO1 inhibitor N-(4-chlorophenyl)-2-((5-phenylthiazolo[2,3-c][1,2,4]triazol-3-yl)thio)acetamide 1 through high-throughput screening (HTS). Herein, we report a structure-activity relationship (SAR) study of this compound, which resulted in the potent IDO1 inhibitor 1-(4-cyanophenyl)-3-(3-(cyclopropylethynyl)imidazo[2,1-b]thiazol-5-yl)thiourea 47 (hIDO IC50 = 16.4 nM). X-ray cocrystal structural analysis revealed that the basis for this high potency is a unique sulfur-aromatic interaction network formed by the thiourea moiety of 47 with F163 and F226. This finding is expected to inspire new approaches toward the discovery of potent IDO1 inhibitors in the future.


Assuntos
Inibidores Enzimáticos/química , Imidazóis/química , Indolamina-Pirrol 2,3,-Dioxigenase/antagonistas & inibidores , Tiazóis/química , Sítios de Ligação , Cristalografia por Raios X , Descoberta de Drogas , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/metabolismo , Humanos , Imidazóis/síntese química , Imidazóis/metabolismo , Indolamina-Pirrol 2,3,-Dioxigenase/química , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Estrutura Molecular , Ligação Proteica , Relação Estrutura-Atividade , Tiazóis/síntese química , Tiazóis/metabolismo
18.
PLoS One ; 15(1): e0228189, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31999754

RESUMO

Cell-penetrating peptides can be used to deliver oligonucleotide-based cargoes into cells. Previous studies have shown that the use of small molecule drugs could be an efficient method to increase the efficacy of delivery of oligonucleotides by cell-penetrating peptides either as targeting agents that can be used in formulation with the cell-penetrating peptide and its cargo or as cell signaling modulators that facilitates the cellular uptake of the treatment. This study presents two aims. The first aim is the identification of small molecule drugs that would induce a synergic effect on the transfection of splice correcting oligonucleotides assisted by PepFect14. The second aim is to identify the mechanisms behind the effect of small molecule drugs modulation of cell-penetrating peptide assisted transfection of oligonucleotides. Through an optimized, high-throughput luciferase assay for short oligonucleotide delivery using cell-penetrating peptides, and the simultaneous addition of a small molecule drug library, we show that three small molecule drugs (MPEP, VU0357121 and Ciproxifan) induced an increase in the transfection efficacy of PepFect14 in complex with a short single-stranded oligonucleotide in HeLa pLuc705 cells. These three drugs are described in the literature to be highly specific for their respective target receptors. However, none of those receptors are expressed in our cell line, indicating a yet non-described pathway of action for these small molecules. We show that the indicated small molecules, without interfering with the particles formed by PepFect14 and the oligonucleotide, interfere via still unidentified interactions in cell signaling, leading to an up-regulation of endocytosis and a higher efficacy in the delivery of short splice correcting oligonucleotides in complex with PepFect14.


Assuntos
Peptídeos Penetradores de Células/metabolismo , Sistemas de Liberação de Medicamentos , Lipopeptídeos/metabolismo , Oligonucleotídeos/metabolismo , Transdução de Sinais , Transfecção , Benzamidas/metabolismo , Endocitose , Células HeLa , Ensaios de Triagem em Larga Escala , Humanos , Imidazóis/metabolismo , Nanopartículas/metabolismo , Oligonucleotídeos/genética , Peptídeos/metabolismo , Piridinas/metabolismo , Receptores de Superfície Celular/metabolismo
19.
Chem Commun (Camb) ; 56(3): 360-363, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31825399

RESUMO

A crystalline biohybrid with a 4 : 1 protein : cucurbituril mass ratio is presented. This result was achieved by engineering additional cucurbit[7]uril (Q7) binding sites into a ß-propeller protein. In contrast to the parent protein, Q7-controlled assembly of the engineered variant occurred in solution, as evidenced by NMR and SAXS measurements.


Assuntos
Proteínas de Bactérias/química , Hidrocarbonetos Aromáticos com Pontes/química , Imidazóis/química , Sequência de Aminoácidos , Proteínas de Bactérias/metabolismo , Sítios de Ligação , Hidrocarbonetos Aromáticos com Pontes/metabolismo , Imidazóis/metabolismo , Lectinas/química , Lectinas/genética , Lectinas/metabolismo , Ressonância Magnética Nuclear Biomolecular , Ralstonia solanacearum/metabolismo , Espalhamento a Baixo Ângulo , Difração de Raios X
20.
Mol Cells ; 43(1): 23-33, 2020 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-31870133

RESUMO

NF-κB signaling through both canonical and non-canonical pathways plays a central role in immune responses and inflammation. NF-κB-inducing kinase (NIK) stabilization is a key step in activation of the non-canonical pathway and its dysregulation implicated in various hematologic malignancies. The tumor suppressor, p53, is an established cellular gatekeeper of proliferation. Abnormalities of the TP53 gene have been detected in more than half of all human cancers. While the non-canonical NF-κB and p53 pathways have been explored for several decades, no studies to date have documented potential cross-talk between these two cancer-related mechanisms. Here, we demonstrate that p53 negatively regulates NIK in an miRNA-dependent manner. Overexpression of p53 decreased the levels of NIK, leading to inhibition of the non-canonical NF-κB pathway. Conversely, its knockdown led to increased levels of NIK, IKKα phosphorylation, and p100 processing. Additionally, miR-34b induced by nutlin-3 directly targeted the coding sequences (CDS) of NIK. Treatment with anti-miR-34b-5p augmented NIK levels and subsequent non-canonical NF-κB signaling. Our collective findings support a novel cross-talk mechanism between non-canonical NF-κB and p53.


Assuntos
MicroRNAs/genética , NF-kappa B/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Endonucleases/genética , Endonucleases/metabolismo , Regulação da Expressão Gênica , Inativação Gênica , Células HeLa , Humanos , Quinase I-kappa B/metabolismo , Imidazóis/metabolismo , Fosforilação , Piperazinas/metabolismo , Transdução de Sinais , Proteína Supressora de Tumor p53/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA