Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 132
Filtrar
1.
Chem Res Toxicol ; 36(3): 380-389, 2023 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-36821091

RESUMO

Over the past decade, there has been increased concern for environmental chemicals that can target various sites within the hypothalamic-pituitary-thyroid axis to potentially disrupt thyroid synthesis, transport, metabolism, and/or function. One well-known thyroid target in both humans and wildlife is the sodium iodide symporter (NIS) that regulates iodide uptake into the thyroid gland, the first step of thyroid hormone synthesis. Our laboratory previously developed and validated a radioactive iodide uptake (RAIU) high-throughput assay in a stably transduced human NIS cell line (hNIS-HEK293T-EPA) to identify chemicals with potential for NIS inhibition. So far, we have tested over 2000 chemicals (US EPA's ToxCast chemical libraries PI_v2, PII, and e1K) and discovered a subset of chemicals that significantly inhibit iodide uptake in the hNIS assay. Here, we utilized this screening assay to test a set of 149 unique per- and polyfluoroalkyl substances (PFAS) (ToxCast PFAS library) for potential NIS inhibition. For this evaluation, the 149 blinded samples were screened in a tiered approach, first in an initial single-concentration (≤100 µM) RAIU assay and subsequent evaluation of the chemicals that produced ≥20% inhibition using multiconcentration (MC) response (0.001-100 µM) testing in parallel RAIU and cell viability assays. Of this set, 38 of the PFAS chemicals inhibited iodide uptake ≥20% in the MC testing with 25 displaying inhibition ≥50%. To prioritize the most potent PFAS NIS inhibitors in this set, chemicals were ranked based on outcomes of both iodide uptake and cytotoxicity and normalized to perchlorate, a known positive control. Consistent with previous findings, PFOS and PFHxS were again found to be potent NIS inhibitors, yet significant inhibition was also observed for several other screened PFAS chemicals. Although further studies are clearly warranted, this initial screening effort identifies NIS as a molecular target for potential thyroid disruption by this persistent and structurally diverse class of chemicals.


Assuntos
Fluorocarbonos , Ensaios de Triagem em Larga Escala , Humanos , Bibliotecas de Moléculas Pequenas/toxicidade , Iodetos/farmacologia , Iodetos/metabolismo , Células HEK293
2.
Artigo em Inglês | MEDLINE | ID: mdl-34454694

RESUMO

Formal requirements for genotoxicity testing of drug candidates to support clinical entry have been in place since the issue of initial regulatory guidance over 25 years ago and subsequent update a decade ago. An evaluation of such testing, supporting first clinical entry of 108 small molecule drug candidates over the last decade, showed that the most common approach (75 % of tested compounds) was for a Good Laboratory Practice test battery in the form of 2 in vitro (a bacterial reverse mutation and a mammalian cell) assays and one in vivo assay. The majority of other tested compounds involved in vitro testing only in bacterial reverse mutation and mammalian cell assays. Testing using a bacterial reverse mutation assay and an in vivo assessment of genotoxicity with 2 different tissues was limited to 2 occasions. For in vitro mammalian cell testing, the chromosome aberration test was most commonly used (70 % occasions), followed by a micronucleus test (16 % occasions) or a mouse lymphoma assay (14 % occasions). For in vivo evaluation, the most common test was a rodent bone marrow micronucleus test (87 % occasions). A positive in vitro mammalian cell assay result was seen on 13 % occasions but was not confirmed with further in vivo testing and the drug candidates were taken into the clinic. In conclusion, the present evaluation showed that the current test battery paradigm for genotoxicity testing has an integral part in supporting clinical entry to confirm candidate drugs taken into the clinic are unlikely to have genotoxic activity.


Assuntos
Desenvolvimento de Medicamentos/métodos , Testes para Micronúcleos/métodos , Testes de Mutagenicidade/métodos , Bibliotecas de Moléculas Pequenas/toxicidade , Animais , Medula Óssea/efeitos dos fármacos , Carcinógenos/toxicidade , Aberrações Cromossômicas/induzido quimicamente , Dano ao DNA/efeitos dos fármacos , Drogas em Investigação/toxicidade , Feminino , Humanos , Técnicas In Vitro/métodos , Linfoma/induzido quimicamente , Masculino , Camundongos , Mutação/efeitos dos fármacos , Ratos , Roedores
3.
ACS Chem Biol ; 16(7): 1288-1297, 2021 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-34232635

RESUMO

Inducing the formation of new oligodendrocytes from oligodendrocyte progenitor cells (OPCs) represents a potential approach to repairing the loss of myelin observed in multiple sclerosis and other diseases. Recently, we demonstrated that accumulation of specific cholesterol precursors, 8,9-unsaturated sterols, is a dominant mechanism by which dozens of small molecules enhance oligodendrocyte formation. Here, we evaluated a library of 56 sterols and steroids to evaluate whether other classes of bioactive sterol derivatives may also influence mouse oligodendrocyte precursor cell (OPC) differentiation or survival. From this library, we identified U-73343 as a potent enhancer of oligodendrocyte formation that induces 8,9-unsaturated sterol accumulation by inhibition of the cholesterol biosynthesis enzyme sterol 14-reductase. In contrast, we found that mouse OPCs are remarkably vulnerable to treatment with the glycosterol OSW-1, an oxysterol-binding protein (OSBP) modulator that induces Golgi stress and OPC death in the low picomolar range. A subsequent small-molecule suppressor screen identified mTOR signaling as a key effector pathway mediating OSW-1's cytotoxic effects in mouse OPCs. Finally, evaluation of a panel of ER and Golgi stress-inducing small molecules revealed that mouse OPCs are highly sensitive to these perturbations, more so than closely related neural progenitor cells. Together, these studies highlight the wide-ranging influence of sterols and steroids on OPC cell fate, with 8,9-unsaturated sterols positively enhancing differentiation to oligodendrocytes and OSW-1 able to induce lethal Golgi stress with remarkable potency.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Células Precursoras de Oligodendrócitos/efeitos dos fármacos , Esteróis/farmacologia , Animais , Sobrevivência Celular/efeitos dos fármacos , Colestenonas/farmacologia , Colestenonas/toxicidade , Avaliação Pré-Clínica de Medicamentos , Retículo Endoplasmático/efeitos dos fármacos , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Estrenos/farmacologia , Complexo de Golgi/efeitos dos fármacos , Células HeLa , Humanos , Camundongos , Células Precursoras de Oligodendrócitos/metabolismo , Oligodendroglia/metabolismo , Pirrolidinonas/farmacologia , Saponinas/farmacologia , Saponinas/toxicidade , Bibliotecas de Moléculas Pequenas/farmacologia , Bibliotecas de Moléculas Pequenas/toxicidade , Esteróis/toxicidade
4.
Eur J Med Chem ; 223: 113606, 2021 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-34171661

RESUMO

Leishmaniasis is a parasitic neglected tropical disease caused by various species of Leishmania parasite. Despite tremendous advancements in the therapeutic sector and drug development strategies, still the existing anti-leishmanial agents are associated with some clinical issues like drug resistance, toxicity and selectivity. Therefore, several research groups are continuously working towards the development of new therapeutic candidates to overcome these issues. Many potential heterocyclic moieties have been explored for this purpose including triazoles, chalcones, chromone, thiazoles, thiosemicarbazones, indole, quinolines, etc. It is evident from the literature that the majority of anti-leishmanial agents act by interacting with key regulators including PTR-I, DHFR, LdMetAP1, MAPK, 14 α-demethylase and pteridine reductase-I, etc. Also, these tend to induce the production of ROS which causes damage to parasites. In the present compilation, authors have summarized various significant synthetic procedures for anti-leishmanial agents reported in recent years. A brief description of the pharmacological potentials of synthesized compounds along with important aspects related to structural activity relationship has been provided. Important docking outcomes highlighting the possible mode of interaction for the reported compounds have also been included. This review would be helpful to the scientific community to design newer strategies and also to develop novel therapeutic candidates against leishmaniasis.


Assuntos
Compostos Heterocíclicos/farmacologia , Leishmaniose/tratamento farmacológico , Tripanossomicidas/farmacologia , Animais , Linhagem Celular Tumoral , Compostos Heterocíclicos/síntese química , Compostos Heterocíclicos/toxicidade , Humanos , Leishmania/efeitos dos fármacos , Estrutura Molecular , Bibliotecas de Moléculas Pequenas/síntese química , Bibliotecas de Moléculas Pequenas/farmacologia , Bibliotecas de Moléculas Pequenas/toxicidade , Relação Estrutura-Atividade , Tripanossomicidas/síntese química , Tripanossomicidas/toxicidade
5.
Bioorg Chem ; 114: 105021, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34120023

RESUMO

The identification of molecules, which could modulate protein-protein interactions (PPIs), is of primary interest to medicinal chemists. Using biophysical methods during the current study, we have screened 76 compounds (grouped into 16 mixtures) against the p8 subunit of the general transcription factor (TFIIH), which has recently been validated as an anti-cancer drug target. 10% of the tested compounds showed interactions with p8 protein in STD-NMR experiments. These results were further validated by molecular docking studies where interactions between compounds and important amino acid residues were identified, including Lys20 in the hydrophobic core of p8, and Asp42 and 43 in the ß3 strand. Moreover, these compounds were able to destabilize the p8 protein by negatively shifting the Tm (≥2 °C) in thermal shift assay. Thus, this study has identified 8 compounds which are likely negative modulators of p8 protein stability, and could be further considered as potential anticancer agents.


Assuntos
Antineoplásicos/química , Bibliotecas de Moléculas Pequenas/química , Fator de Transcrição TFIIH/antagonistas & inibidores , Antineoplásicos/metabolismo , Antineoplásicos/toxicidade , Linhagem Celular , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Ligação de Hidrogênio , Simulação de Acoplamento Molecular , Ligação Proteica , Bibliotecas de Moléculas Pequenas/metabolismo , Bibliotecas de Moléculas Pequenas/toxicidade , Eletricidade Estática , Fator de Transcrição TFIIH/química , Fator de Transcrição TFIIH/metabolismo
6.
Molecules ; 26(3)2021 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-33525350

RESUMO

Plant hormones are small regulatory molecules that exert pharmacological actions in mammalian cells such as anti-oxidative and pro-metabolic effects. Kinetin belongs to the group of plant hormones cytokinin and has been associated with modulatory functions in mammalian cells. The mammalian adenosine receptor (A2a-R) is known to modulate multiple physiological responses in animal cells. Here, we describe that kinetin binds to the adenosine receptor (A2a-R) through the Asn253 residue in an adenosine dependent manner. To harness the beneficial effects of kinetin for future human use, we assess its acute toxicity by analyzing different biochemical and histological markers in rats. Kinetin at a dose below 1 mg/kg had no adverse effects on the serum level of glucose or on the activity of serum alanine transaminase (ALT) or aspartate aminotransferase (AST) enzymes in the kinetin treated rats. Whereas, creatinine levels increased after a kinetin treatment at a dose of 0.5 mg/kg. Furthermore, 5 mg/kg treated kinetin rats showed normal renal corpuscles, but a mild degeneration was observed in the renal glomeruli and renal tubules, as well as few degenerated hepatocytes were also observed in the liver. Kinetin doses below 5 mg/kg did not show any localized toxicity in the liver and kidney tissues. In addition to unraveling the binding interaction between kinetin and A2a-R, our findings suggest safe dose limits for the future use of kinetin as a therapeutic and modulatory agent against various pathophysiological conditions.


Assuntos
Cinetina/farmacologia , Cinetina/toxicidade , Bibliotecas de Moléculas Pequenas/farmacologia , Bibliotecas de Moléculas Pequenas/toxicidade , Animais , Antioxidantes/fisiologia , Antioxidantes/toxicidade , Biomarcadores/metabolismo , Creatinina/metabolismo , Citocininas/metabolismo , Glucose/metabolismo , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Humanos , Glomérulos Renais/efeitos dos fármacos , Glomérulos Renais/metabolismo , Túbulos Renais/efeitos dos fármacos , Túbulos Renais/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Oxirredução/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Reguladores de Crescimento de Plantas/farmacologia , Reguladores de Crescimento de Plantas/toxicidade , Ratos , Receptores Purinérgicos P1/metabolismo
7.
Chem Res Toxicol ; 34(2): 189-216, 2021 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-33140634

RESUMO

Since 2009, the Tox21 project has screened ∼8500 chemicals in more than 70 high-throughput assays, generating upward of 100 million data points, with all data publicly available through partner websites at the United States Environmental Protection Agency (EPA), National Center for Advancing Translational Sciences (NCATS), and National Toxicology Program (NTP). Underpinning this public effort is the largest compound library ever constructed specifically for improving understanding of the chemical basis of toxicity across research and regulatory domains. Each Tox21 federal partner brought specialized resources and capabilities to the partnership, including three approximately equal-sized compound libraries. All Tox21 data generated to date have resulted from a confluence of ideas, technologies, and expertise used to design, screen, and analyze the Tox21 10K library. The different programmatic objectives of the partners led to three distinct, overlapping compound libraries that, when combined, not only covered a diversity of chemical structures, use-categories, and properties but also incorporated many types of compound replicates. The history of development of the Tox21 "10K" chemical library and data workflows implemented to ensure quality chemical annotations and allow for various reproducibility assessments are described. Cheminformatics profiling demonstrates how the three partner libraries complement one another to expand the reach of each individual library, as reflected in coverage of regulatory lists, predicted toxicity end points, and physicochemical properties. ToxPrint chemotypes (CTs) and enrichment approaches further demonstrate how the combined partner libraries amplify structure-activity patterns that would otherwise not be detected. Finally, CT enrichments are used to probe global patterns of activity in combined ToxCast and Tox21 activity data sets relative to test-set size and chemical versus biological end point diversity, illustrating the power of CT approaches to discern patterns in chemical-activity data sets. These results support a central premise of the Tox21 program: A collaborative merging of programmatically distinct compound libraries would yield greater rewards than could be achieved separately.


Assuntos
Bibliotecas de Moléculas Pequenas/toxicidade , Testes de Toxicidade , Ensaios de Triagem em Larga Escala , Humanos , Estados Unidos , United States Environmental Protection Agency
8.
Int J Mol Sci ; 21(24)2020 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-33322848

RESUMO

Botulinum toxins are neurotoxins produced by Clostridium botulinum. This toxin can be lethal for humans as a cause of botulism; however, in small doses, the same toxin is used to treat different conditions. Even if the therapeutic doses are effective and safe, the adverse reactions could be local and could unmask a subclinical impairment of neuromuscular transmissions. There are not many cases of adverse events in the literature; however, it is possible that sometimes they do not occur as they are transient and, if they do occur, there is no possibility of a cure other than to wait for the pharmacological effect to end. Inhibition of botulinum neurotoxin type A (BoNT/A) effects is a strategy for treating botulism as it can provide an effective post-exposure remedy. In this paper, 13,592,287 compounds were screened through a pharmacophore filter, a 3D-QSAR model, and a virtual screening; then, the compounds with the best affinity were selected. Molecular dynamics simulation studies on the first four compounds predicted to be the most active were conducted to verify that the poses foreseen by the docking were stable. This approach allowed us to identify compounds with a calculated inhibitory activity in the range of 316-500 nM.


Assuntos
Toxinas Botulínicas Tipo A/antagonistas & inibidores , Toxinas Botulínicas Tipo A/química , Simulação de Dinâmica Molecular , Relação Quantitativa Estrutura-Atividade , Bibliotecas de Moléculas Pequenas/farmacocinética , Toxinas Botulínicas Tipo A/efeitos adversos , Toxinas Botulínicas Tipo A/uso terapêutico , Clostridium botulinum/química , Bases de Dados Factuais , Ligação de Hidrogênio , Modelos Químicos , Modelos Moleculares , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/farmacologia , Bibliotecas de Moléculas Pequenas/toxicidade , Eletricidade Estática
9.
Bioorg Med Chem Lett ; 30(23): 127616, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-33091607

RESUMO

The compounds from eight different thiazolidine and thiazole series were assessed as potential antileishmanial scaffolds. They were tested for antileishmanial activity against promastigotes of Leishmania major using in vitro primary screen and dose response assays. The compounds from six thiazolidine and thiazole series were identified as the hits with antileishmanial activity against L. major. However, the analyses of structure-activity relations (SARs) showed that the interpretable SARs were obtained only for phenyl-indole hybrids (compounds C1, C2, C3 and C5) as the most effective compounds against L. major promastigotes (IC50 < 10 µM) with low toxicity to human fibroblasts. For the scaffold of these compounds, the most significant SAR patterns were: free N3 position of thiazolidinone core, absence of big fragments at the C5 position of thiazolidinone core and presence of halogen atoms or nitro group in the phenyl ring of phenyl-indole fragment. As previous studies showed that these compounds also have activity against the two Trypanosoma species, Trypanosoma brucei and Trypanosoma gambiense, their scaffold could be associated with a broader antiparasitic activity.


Assuntos
Tiazolidinas/farmacologia , Tripanossomicidas/farmacologia , Fibroblastos/efeitos dos fármacos , Humanos , Leishmania major/efeitos dos fármacos , Estrutura Molecular , Testes de Sensibilidade Parasitária , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/farmacologia , Bibliotecas de Moléculas Pequenas/toxicidade , Relação Estrutura-Atividade , Tiazolidinas/química , Tiazolidinas/toxicidade , Tripanossomicidas/química , Tripanossomicidas/toxicidade , Trypanosoma brucei brucei/efeitos dos fármacos , Trypanosoma brucei gambiense/efeitos dos fármacos
10.
J Med Chem ; 63(17): 10030-10044, 2020 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-32787113

RESUMO

To discover novel BChE inhibitors, a hierarchical virtual screening protocol followed by biochemical evaluation was applied. The most potent compound 8012-9656 (eqBChE IC50 = 0.18 ± 0.03 µM, hBChE IC50 = 0.32 ± 0.07 µM) was purchased and synthesized. It inhibited BChE in a noncompetitive manner and could occupy the binding pocket forming diverse interactions with the target. 8012-9656 was proven to be safe in vivo and in vitro and showed comparable performance in ameliorating the scopolamine-induced cognition impairment to tacrine. Additionally, treatment with 8012-9656 could almost entirely recover the Aß1-42 (icv)-impaired cognitive function to the normal level and showed better behavioral performance than donepezil. The evaluation of the Aß1-42 total amount confirmed its anti-amyloidogenic profile. Moreover, 8012-9656 possessed blood-brain barrier (BBB) penetrating ability, a long T1/2, and low intrinsic clearance. Hence, the novel potential BChE inhibitor 8012-9656 can be considered as a promising lead compound for further investigation of anti-AD agents.


Assuntos
Aminoquinolinas/farmacologia , Benzimidazóis/farmacologia , Butirilcolinesterase/metabolismo , Inibidores da Colinesterase/farmacologia , Fármacos Neuroprotetores/farmacologia , Aminoquinolinas/síntese química , Aminoquinolinas/metabolismo , Aminoquinolinas/toxicidade , Animais , Benzimidazóis/síntese química , Benzimidazóis/metabolismo , Benzimidazóis/toxicidade , Linhagem Celular Tumoral , Inibidores da Colinesterase/síntese química , Inibidores da Colinesterase/metabolismo , Inibidores da Colinesterase/toxicidade , Descoberta de Drogas , Avaliação Pré-Clínica de Medicamentos , Feminino , Humanos , Masculino , Camundongos Endogâmicos ICR , Microssomos Hepáticos/metabolismo , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Fármacos Neuroprotetores/síntese química , Fármacos Neuroprotetores/metabolismo , Fármacos Neuroprotetores/toxicidade , Ligação Proteica , Bibliotecas de Moléculas Pequenas/síntese química , Bibliotecas de Moléculas Pequenas/metabolismo , Bibliotecas de Moléculas Pequenas/farmacologia , Bibliotecas de Moléculas Pequenas/toxicidade
11.
Acta Pharmacol Sin ; 41(10): 1328-1336, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32235863

RESUMO

Relaxin/insulin-like family peptide receptor 4 (RXFP4) is a class A G protein-coupled receptor (GPCR), and insulin-like peptide 5 (INSL5) is its endogenous ligand. Although the precise physiological role of INSL5/RXFP4 remains elusive, a number of studies have suggested it to be a potential therapeutic target for obesity and other metabolic disorders. Since selective agonists of RXFP4 are scarcely available and peptidic analogs of INSL5 are hard to make, we conducted a high-throughput screening campaign against 52,000 synthetic and natural compounds targeting RXFP4. Of the 109 initial hits discovered, only 3 compounds were confirmed in secondary screening, with JK0621-D008 displaying the best agonism at human RXFP4. Its S-configuration stereoisomer (JK1) was subsequently isolated and validated by a series of bioassays, demonstrating a consistent agonistic effect in cells overexpressing RXFP4. This scaffold may provide a valuable tool to further explore the biological functions of RXFP4.


Assuntos
Receptores Acoplados a Proteínas G/agonistas , Receptores de Peptídeos/agonistas , Bibliotecas de Moléculas Pequenas/farmacologia , Animais , Células CHO , Cricetulus , Células HEK293 , Ensaios de Triagem em Larga Escala , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Camundongos , Bibliotecas de Moléculas Pequenas/toxicidade
12.
ACS Chem Biol ; 15(4): 1026-1035, 2020 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-32142251

RESUMO

The 14-3-3/c-Abl protein-protein interaction (PPI) is related to carcinogenesis and in particular to pathogenesis of chronic myeloid leukemia (CML). Previous studies have demonstrated that molecules able to disrupt this interaction improve the nuclear translocation of c-Abl, inducing apoptosis in leukemia cells. Through an X-ray crystallography screening program, we have identified two phosphate-containing compounds, inosine monophosphate (IMP) and pyridoxal phosphate (PLP), as binders of human 14-3-3σ, by targeting the protein amphipathic groove. Interestingly, they also act as weak inhibitors of the 14-3-3/c-Abl PPI, demonstrated by NMR, SPR, and FP data. A 37-compound library of PLP and IMP analogues was investigated using a FP assay, leading to the identification of three further molecules acting as weak inhibitors of the 14-3-3/c-Abl complex formation. The antiproliferative activity of IMP, PLP, and the three derivatives was tested against K-562 cells, showing that the parent compounds had the most pronounced effect on tumor cells. PLP and IMP were also effective in promoting the c-Abl nuclear translocation in c-Abl overexpressing cells. Further, these compounds demonstrated low cytotoxicity on human Hs27 fibroblasts. In conclusion, our data suggest that 14-3-3σ targeting compounds represent promising hits for further development of drugs against c-Abl-dependent cancers.


Assuntos
Proteínas 14-3-3/antagonistas & inibidores , Exorribonucleases/antagonistas & inibidores , Organofosfatos/farmacologia , Ligação Proteica/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-abl/antagonistas & inibidores , Bibliotecas de Moléculas Pequenas/farmacologia , Proteínas 14-3-3/química , Proteínas 14-3-3/metabolismo , Sequência de Aminoácidos , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Antineoplásicos/toxicidade , Núcleo Celular/metabolismo , Cristalografia por Raios X , Ensaios de Seleção de Medicamentos Antitumorais , Exorribonucleases/química , Exorribonucleases/metabolismo , Humanos , Inosina Monofosfato/metabolismo , Inosina Monofosfato/farmacologia , Inosina Monofosfato/toxicidade , Células K562 , Organofosfatos/metabolismo , Organofosfatos/toxicidade , Proteínas Proto-Oncogênicas c-abl/metabolismo , Fosfato de Piridoxal/metabolismo , Fosfato de Piridoxal/farmacologia , Fosfato de Piridoxal/toxicidade , Alinhamento de Sequência , Bibliotecas de Moléculas Pequenas/toxicidade
13.
J Med Chem ; 63(7): 3763-3783, 2020 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-32189500

RESUMO

The immunoproteasome (iP), an inducible proteasome variant harboring three immunosubunits, low molecular mass polypeptide-2 (LMP2), multicatalytic endopeptidase complex subunit-1, and low molecular mass polypeptide-7 (LMP7), is involved in multiple facets of inflammatory responses. We recently reported that YU102, a dual inhibitor of the iP subunit LMP2 and the constitutive proteasome catalytic subunit ß1, ameliorates cognitive impairments in mouse models of Alzheimer's disease (AD) independently of amyloid deposits. To investigate whether inhibition of LMP2 is sufficient to improve the cognitive functions of AD mice, here we prepared 37 YU102 analogues and identified a potent LMP2 inhibitor DB-310 (28) (IC50: 80.6 nM) with improved selectivity and permeability in cells overexpressing ABCB1 transporters. We show that DB-310 induces suppression of IL-1α production in microglia cells and improves cognitive functions in the Tg2576 transgenic mouse model of AD. This study supports that inhibition of LMP2 is a promising therapeutic strategy for treatment of AD.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Cisteína Endopeptidases/metabolismo , Inibidores de Cisteína Proteinase/uso terapêutico , Nootrópicos/uso terapêutico , Oligopeptídeos/uso terapêutico , Animais , Linhagem Celular Transformada , Inibidores de Cisteína Proteinase/síntese química , Inibidores de Cisteína Proteinase/toxicidade , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Humanos , Interleucina-1alfa/metabolismo , Camundongos Transgênicos , Microglia/efeitos dos fármacos , Estrutura Molecular , Nootrópicos/síntese química , Nootrópicos/toxicidade , Oligopeptídeos/síntese química , Oligopeptídeos/toxicidade , Bibliotecas de Moléculas Pequenas/síntese química , Bibliotecas de Moléculas Pequenas/uso terapêutico , Bibliotecas de Moléculas Pequenas/toxicidade , Relação Estrutura-Atividade
14.
ACS Chem Biol ; 15(2): 388-395, 2020 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-31944659

RESUMO

With the aim to develop novel antiviral agents against Kaposi's Sarcoma Herpesvirus (KSHV), we are targeting the latency-associated nuclear antigen (LANA). This protein plays an important role in viral genome maintenance during latent infection. LANA has the ability to tether the viral genome to the host nucleosomes and, thus, ensures latent persistence of the viral genome in the host cells. By inhibition of the LANA-DNA interaction, we seek to eliminate or reduce the load of the viral DNA in the host. To achieve this goal, we screened our in-house library using a dedicated fluorescence polarization (FP)-based competition assay, which allows for the quantification of LANA-DNA-interaction inhibition by small organic molecules. We successfully identified three different compound classes capable of disrupting this protein-nucleic acid interaction. We characterized these compounds by IC50 dose-response evaluation and confirmed the compound-LANA interaction using surface plasmon resonance (SPR) spectroscopy. Furthermore, two of the three hit scaffolds showed only marginal cytotoxicity in two human cell lines. Finally, we conducted STD-NMR competition experiments with our new hit compounds and a previously described fragment-sized inhibitor. Based on these results, future compound linking approaches could serve as a promising strategy for further optimization studies in order to generate highly potent KSHV inhibitors.


Assuntos
Antivirais/farmacologia , Herpesvirus Humano 8/efeitos dos fármacos , Proteínas Nucleares/antagonistas & inibidores , Antígenos Virais/metabolismo , Antivirais/toxicidade , DNA/metabolismo , Descoberta de Drogas , Células HEK293 , Células Hep G2 , Humanos , Testes de Sensibilidade Microbiana , Proteínas Nucleares/metabolismo , Ligação Proteica/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/farmacologia , Bibliotecas de Moléculas Pequenas/toxicidade
15.
J Med Chem ; 63(9): 4411-4429, 2020 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-31928004

RESUMO

Negative design is a group of virtual screening methods that aims at weeding out compounds with undesired properties during the early stages of drug development. These methods are mainly designed to predict three important types of pharmacological properties: drug-likeness, frequent hitters, and toxicity. In order to achieve high screening efficiency, most negative design methods are physicochemical property-based and/or substructure-based rules or filters. Such methods have advantages of simplicity and good interpretability, but they also suffer from some defects such as inflexibility, discontinuity, and hard decision-making. In this review, the advances in negative design for the evaluations of drug-likeness, frequent hitters, and toxicity are outlined. In addition, the related Web servers and software packages developed recently for negative design are summarized. Finally, future research directions in this field are discussed.


Assuntos
Desenho de Fármacos , Bibliotecas de Moléculas Pequenas/química , Animais , Descoberta de Drogas , Avaliação Pré-Clínica de Medicamentos , Humanos , Internet , Bibliotecas de Moléculas Pequenas/toxicidade , Software
16.
SAR QSAR Environ Res ; 31(3): 209-226, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31916862

RESUMO

The aryl hydrocarbon receptor (AhR) plays an important role in several biological processes such as reproduction, immunity and homoeostasis. However, little is known on the chemical-structural and physicochemical features that influence the activity of AhR antagonistic modulators. In the present report, in vitro AhR antagonistic activity evaluations, based on a chemical-activated luciferase gene expression (AhR-CALUX) bioassay, and an extensive literature review were performed with the aim of constructing a structurally diverse database of contaminants and potentially toxic chemicals. Subsequently, QSAR models based on Linear Discriminant Analysis and Logistic Regression, as well as two toxicophoric hypotheses were proposed to model the AhR antagonistic activity of the built dataset. The QSAR models were rigorously validated yielding satisfactory performance for all classification parameters. Likewise, the toxicophoric hypotheses were validated using a diverse set of 350 decoys, demonstrating adequate robustness and predictive power. Chemical interpretations of both the QSAR and toxicophoric models suggested that hydrophobic constraints, the presence of aromatic rings and electron-acceptor moieties are critical for the AhR antagonism. Therefore, it is hoped that the deductions obtained in the present study will contribute to elucidate further on the structural and physicochemical factors influencing the AhR antagonistic activity of chemical compounds.


Assuntos
Receptores de Hidrocarboneto Arílico/antagonistas & inibidores , Receptores de Hidrocarboneto Arílico/química , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Poluentes Ambientais/química , Poluentes Ambientais/toxicidade , Luciferases/genética , Luciferases/metabolismo , Modelos Moleculares , Relação Quantitativa Estrutura-Atividade , Receptores de Hidrocarboneto Arílico/genética , Receptores de Hidrocarboneto Arílico/metabolismo , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Reprodutibilidade dos Testes , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/toxicidade
17.
ACS Appl Mater Interfaces ; 12(19): 21270-21282, 2020 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-31917544

RESUMO

We synthesized a combinatorial library of dendrons that display a cluster of cationic charges juxtaposed with a hydrophobic alkyl chain, using the so-called "molecular umbrella" design approach. Systematically tuning the generation number and alkyl chain length enabled a detailed study of the structure-activity relationships in terms of both hydrophobic content and number of cationic charges. These discrete, unimolecular compounds display rapid and broad-spectrum bactericidal activity comparable to the activity of antibacterial peptides. Micellization was examined by pyrene emission and dynamic light scattering, which revealed that monomeric, individually solvated dendrons are present in aqueous media. The antibacterial mechanism of action is putatively driven by the membrane-disrupting nature of these cationic surfactants, which we confirmed by enzymatic assays on E. coli cells. The hemolytic activity of these dendritic macromolecules is sensitively dependent on the dendron generation and the alkyl chain length. Via structural optimization of these two key design features, we identified a leading candidate with potent broad-spectrum antibacterial activity (4-8 µg/mL) combined with outstanding hemocompatibility (up to 5000 µg/mL). This selected compound is >1000-fold more active against bacteria as compared to red blood cells, which represents one of the highest selectivity index values ever reported for a membrane-disrupting antibacterial agent. Thus, the leading candidate from this initial library screen holds great potential for future applications as a nontoxic, degradable disinfectant.


Assuntos
Antibacterianos/farmacologia , Dendrímeros/farmacologia , Tensoativos/farmacologia , beta-Alanina/análogos & derivados , beta-Alanina/farmacologia , Antibacterianos/síntese química , Antibacterianos/toxicidade , Membrana Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Dendrímeros/síntese química , Dendrímeros/toxicidade , Escherichia coli/efeitos dos fármacos , Células HeLa , Humanos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Bibliotecas de Moléculas Pequenas/síntese química , Bibliotecas de Moléculas Pequenas/farmacologia , Bibliotecas de Moléculas Pequenas/toxicidade , Staphylococcus aureus/efeitos dos fármacos , Relação Estrutura-Atividade , Tensoativos/síntese química , Tensoativos/toxicidade , beta-Alanina/toxicidade
18.
Biochem Pharmacol ; 174: 113796, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31926938

RESUMO

Basic amine substituents provide several pharmacokinetic benefits relative to acidic and neutral functional groups, and have been extensively utilized as substituents of choice in drug design. On occasions, basic amines have been associated with off-target pharmacology via interactions with aminergic G-protein coupled receptors, ion-channels, kinases, etc. Structural features associated with the promiscuous nature of basic amines have been well-studied, and can be mitigated in a preclinical drug discovery environment. In addition to the undesirable secondary pharmacology, α-carbon oxidation of certain secondary or tertiary cycloalkyl amines can generate electrophilic iminium and aldehyde metabolites, potentially capable of covalent adduction to proteins or DNA. Consequently, cycloalkyl amines have been viewed as structural alerts (SAs), analogous to functional groups such as anilines, furans, thiophenes, etc., which are oxidized to reactive metabolites that generate immunogenic haptens by covalently binding to host proteins. Detailed survey of the literature, however, suggests that cases where preclinical or clinical toxicity has been explicitly linked to the metabolic activation of a cycloalkyl amine group are extremely rare. Moreover, there is a distinct possibility for the formation of electrophilic iminium/amino-aldehyde metabolites with numerous cycloalkyl amine-containing marketed drugs, since stable ring cleavage products have been characterized as metabolites in human mass balance studies. In the present work, a critical analysis of the evidence for and against the role of iminium ions/aldehydes as mediators of toxicity is discussed with a special emphasis on often time overlooked detoxication pathways of these reactive species to innocuous metabolites.


Assuntos
Aminas/toxicidade , Cicloparafinas/toxicidade , Bibliotecas de Moléculas Pequenas/toxicidade , Aminas/química , Animais , Cicloparafinas/química , Desenho de Fármacos , Descoberta de Drogas , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/etiologia , Humanos , Bibliotecas de Moléculas Pequenas/química , Relação Estrutura-Atividade
19.
J Bioinform Comput Biol ; 17(5): 1950033, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31744364

RESUMO

In this study, efforts are created to develop a quantitative structure-activity relationship (QSAR)-based model, which are used for the prediction of toxicities to reduce testing in animals, time, and money in the early stages of drug development. An efficient machine learning model is developed to predict the toxicity of those drug molecules which binds to the androgen receptor (AR). Toxicity prediction is performed in terms of their activity, activity score, potency, and efficacy by using various physicochemical properties. A multilevel ensemble model is proposed, where its first level is performed ensemble-based classification of activity, and the second level is performed ensemble-based regression of activity score, potency, and efficacy of only those drug molecules which have been found active during the classification level. The AR dataset has 10,273 drug molecules where 461 are active, and 9812 are inactive, and each drug molecule has 1444 features. Therefore, our dataset is highly imbalanced having a very large number of features. Initially, we performed feature selection then the class imbalance problem is resolved. The k-fold cross-validation is accomplished to measure the consistency of the model. Finally, our proposed multilevel ensemble model has been validated and compared with some existing models.


Assuntos
Relação Quantitativa Estrutura-Atividade , Receptores Androgênicos , Bibliotecas de Moléculas Pequenas/toxicidade , Testes de Toxicidade/métodos , Simulação por Computador , Humanos , Modelos Lineares , Aprendizado de Máquina , Redes Neurais de Computação , Distribuição Aleatória , Receptores Androgênicos/efeitos dos fármacos , Reprodutibilidade dos Testes , Bibliotecas de Moléculas Pequenas/química
20.
Sci Rep ; 9(1): 16947, 2019 11 18.
Artigo em Inglês | MEDLINE | ID: mdl-31740740

RESUMO

The over-expression and aggregation of α-synuclein (αSyn) are linked to the onset and pathology of Parkinson's disease. Native monomeric αSyn exists in an intrinsically disordered ensemble of interconverting conformations, which has made its therapeutic targeting by small molecules highly challenging. Nonetheless, here we successfully target the monomeric structural ensemble of αSyn and thereby identify novel drug-like small molecules that impact multiple pathogenic processes. Using a surface plasmon resonance high-throughput screen, in which monomeric αSyn is incubated with microchips arrayed with tethered compounds, we identified novel αSyn interacting drug-like compounds. Because these small molecules could impact a variety of αSyn forms present in the ensemble, we tested representative hits for impact on multiple αSyn malfunctions in vitro and in cells including aggregation and perturbation of vesicular dynamics. We thereby identified a compound that inhibits αSyn misfolding and is neuroprotective, multiple compounds that restore phagocytosis impaired by αSyn overexpression, and a compound blocking cellular transmission of αSyn. Our studies demonstrate that drug-like small molecules that interact with native αSyn can impact a variety of its pathological processes. Thus, targeting the intrinsically disordered ensemble of αSyn offers a unique approach to the development of small molecule research tools and therapeutics for Parkinson's disease.


Assuntos
Bibliotecas de Moléculas Pequenas/farmacologia , alfa-Sinucleína/metabolismo , Amiloide/antagonistas & inibidores , Amiloide/metabolismo , Linhagem Celular , Transferência Ressonante de Energia de Fluorescência , Ensaios de Triagem em Larga Escala/métodos , Humanos , Proteínas Intrinsicamente Desordenadas/metabolismo , Fagocitose/efeitos dos fármacos , Dobramento de Proteína , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/toxicidade , Ressonância de Plasmônio de Superfície , alfa-Sinucleína/química , alfa-Sinucleína/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...