Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 181
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Parasitology ; 151(5): 506-513, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38533610

RESUMO

Leishmania is a trypanosomatid parasite that causes skin lesions in its cutaneous form. Current therapies rely on old and expensive drugs, against which the parasites have acquired considerable resistance. Trypanosomatids are unable to synthesize purines relying on salvaging from the host, and nucleoside analogues have emerged as attractive antiparasitic drug candidates. 4-Methyl-7-ß-D-ribofuranosyl-7H-pyrrolo[2,3-d]pyrimidine (CL5564), an analogue of tubercidin in which the amine has been replaced by a methyl group, demonstrates activity against Trypanosoma cruzi and Leishmania infantum. Herein, we investigated its in vitro and in vivo activity against L. amazonensis. CL5564 was 6.5-fold (P = 0.0002) more potent than milteforan™ (ML) against intracellular forms in peritoneal mouse macrophages, and highly selective, while combination with ML gave an additive effect. These results stimulated us to study the activity of CL5564 in mouse model of cutaneous Leishmania infection. BALB/c female and male mice infected by L. amazonensis treated with CL5564 (10 mg kg−1, intralesional route for five days) presented a >93% reduction of paw lesion size likely ML given orally at 40 mg kg−1, while the combination (10 + 40 mg kg−1 of CL5564 and ML, respectively) caused >96% reduction. The qPCR confirmed the suppression of parasite load, but only the combination approach reached 66% of parasitological cure. These results support additional studies with nucleoside derivatives.


Assuntos
Modelos Animais de Doenças , Leishmania mexicana , Leishmaniose Cutânea , Camundongos Endogâmicos BALB C , Animais , Leishmaniose Cutânea/tratamento farmacológico , Leishmaniose Cutânea/parasitologia , Camundongos , Feminino , Masculino , Leishmania mexicana/efeitos dos fármacos , Tubercidina/farmacologia , Tubercidina/análogos & derivados , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Antiprotozoários/administração & dosagem , Macrófagos Peritoneais/parasitologia , Macrófagos Peritoneais/efeitos dos fármacos , Leishmania/efeitos dos fármacos
2.
Bioorg Chem ; 140: 106809, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37651896

RESUMO

In the past decades an increasing number of studies revealed that G protein-coupled receptors (GPCRs) are capable of forming dimers or even higher-ordered oligomers, which may modulate receptor function and act as potential drug targets. In this review, we briefly summarized the design strategy of bivalent GPCR ligands and mainly focused on how to use them to study and/or detect GPCP dimerization in vitro and in vivo. Bivalent ligands show specific properties relative to their corresponding monomeric ligands because they are able to bind to GPCR homodimers or heterodimers simultaneously. For example, bivalent ligands with optimal length of spacers often exhibited higher binding affinities for dimers compared to that of monomers. Furthermore, bivalent ligands displayed specific signal transduction compared to monovalent ligands. Finally, we give our perspective on targeting GPCR dimers from traditional bivalent ligands to more drug-like small molecules.


Assuntos
Receptores Acoplados a Proteínas G , Transdução de Sinais , Ligantes , Dimerização , Membrana Celular , Polímeros
3.
Int J Mol Sci ; 24(4)2023 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-36834557

RESUMO

African Animal Trypanosomiasis (AAT), caused predominantly by Trypanosoma brucei brucei, T. vivax and T. congolense, is a fatal livestock disease throughout Sub-Saharan Africa. Treatment options are very limited and threatened by resistance. Tubercidin (7-deazaadenosine) analogs have shown activity against individual parasites but viable chemotherapy must be active against all three species. Divergence in sensitivity to nucleoside antimetabolites could be caused by differences in nucleoside transporters. Having previously characterized the T. brucei nucleoside carriers, we here report the functional expression and characterization of the main adenosine transporters of T. vivax (TvxNT3) and T. congolense (TcoAT1/NT10), in a Leishmania mexicana cell line ('SUPKO') lacking adenosine uptake. Both carriers were similar to the T. brucei P1-type transporters and bind adenosine mostly through interactions with N3, N7 and 3'-OH. Expression of TvxNT3 and TcoAT1 sensitized SUPKO cells to various 7-substituted tubercidins and other nucleoside analogs although tubercidin itself is a poor substrate for P1-type transporters. Individual nucleoside EC50s were similar for T. b. brucei, T. congolense, T. evansi and T. equiperdum but correlated less well with T. vivax. However, multiple nucleosides including 7-halogentubercidines displayed pEC50>7 for all species and, based on transporter and anti-parasite SAR analyses, we conclude that nucleoside chemotherapy for AAT is viable.


Assuntos
Trypanosoma congolense , Tripanossomíase Africana , Animais , Tripanossomíase Africana/parasitologia , Nucleosídeos/uso terapêutico , Tubercidina/uso terapêutico , Adenosina/uso terapêutico , Clonagem Molecular
4.
Int J Mol Sci ; 23(2)2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-35054895

RESUMO

Toxoplasma gondii is unable to synthesize purines de novo, instead salvages them from its environment, inside the host cell, for which they need high affinity carriers. Here, we report the expression of a T. gondii Equilibrative Nucleoside Transporter, Tg244440, in a Trypanosoma brucei strain from which nucleobase transporters have been deleted. Tg244440 transported hypoxanthine and guanine with similar affinity (Km ~1 µM), while inosine and guanosine displayed Ki values of 4.05 and 3.30 µM, respectively. Low affinity was observed for adenosine, adenine, and pyrimidines, classifying Tg244440 as a high affinity oxopurine transporter. Purine analogues were used to probe the substrate-transporter binding interactions, culminating in quantitative models showing different binding modes for oxopurine bases, oxopurine nucleosides, and adenosine. Hypoxanthine and guanine interacted through protonated N1 and N9, and through unprotonated N3 and N7 of the purine ring, whereas inosine and guanosine mostly employed the ribose hydroxy groups for binding, in addition to N1H of the nucleobase. Conversely, the ribose moiety of adenosine barely made any contribution to binding. Tg244440 is the first gene identified to encode a high affinity oxopurine transporter in T. gondii and, to the best of our knowledge, the first purine transporter to employ different binding modes for nucleosides and nucleobases.


Assuntos
Proteínas de Transporte de Nucleosídeos/metabolismo , Nucleosídeos/metabolismo , Purinonas/metabolismo , Toxoplasma/fisiologia , Toxoplasmose/parasitologia , Fibroblastos , Técnicas de Silenciamento de Genes , Humanos , Proteínas de Transporte de Nucleosídeos/genética , Nucleosídeos/química , Filogenia , Ligação Proteica , Purinonas/química , Toxoplasma/classificação
5.
Int J Mol Sci ; 23(16)2022 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-36012151

RESUMO

We report the design, synthesis, and validation of the novel compound photocaged N6-cyclopentyladenosine (cCPA) to achieve precisely localized and timed release of the parent adenosine A1 receptor agonist CPA using 405 nm light. Gi protein-coupled A1 receptors (A1Rs) modulate neurotransmission via pre- and post-synaptic routes. The dynamics of the CPA-mediated effect on neurotransmission, characterized by fast activation and slow recovery, make it possible to implement a closed-loop control paradigm. The strength of neurotransmission is monitored as the amplitude of stimulus-evoked local field potentials. It is used for feedback control of light to release CPA. This system makes it possible to regulate neurotransmission to a pre-defined level in acute hippocampal brain slices incubated with 3 µM cCPA. This novel approach of closed-loop photopharmacology holds therapeutic potential for fine-tuned control of neurotransmission in diseases associated with neuronal hyperexcitability.


Assuntos
Agonistas do Receptor A1 de Adenosina , Receptor A1 de Adenosina , Agonistas do Receptor A1 de Adenosina/farmacologia , Retroalimentação , Hipocampo/metabolismo , Receptor A1 de Adenosina/metabolismo , Transmissão Sináptica , Xantinas/farmacologia
6.
Molecules ; 27(22)2022 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-36432150

RESUMO

Among the scarce validated drug targets against Chagas disease (CD), caused by Trypanosoma cruzi, the parasite's nucleoside salvage system has recently attracted considerable attention. Although the trypanocidal activity of tubercidin (7-deazapurine) has long been known, the identification of a class of 7-substituted tubercidin analogs with potent in vitro and in vivo activity and much-enhanced selectivity has made nucleoside analogs among the most promising lead compounds against CD. Here, we investigate the recently identified TcrNT2 nucleoside transporter and its potential role in antimetabolite chemotherapy. TcrNT2, expressed in a Leishmania mexicana cell line lacking the NT1 nucleoside transporter locus, displayed very high selectivity and affinity for thymidine with a Km of 0.26 ± 0.05 µM. The selectivity was explained by interactions of 2-oxo, 4-oxo, 5-Me, 3'-hydroxy and 5'-hydroxy with the transporter binding pocket, whereas a hydroxy group at the 2' position was deleterious to binding. This made 5-halogenated 2'-deoxyuridine analogues good substrates but 5-F-2'-deoxyuridine displayed disappointing activity against T. cruzi trypomastigotes. By comparing the EC50 values of tubercidin and its 7-substituted analogues against L. mexicana Cas9, Cas9ΔNT1 and Cas9ΔNT1+TcrNT2 it was shown that TcrNT2 can take up tubercidin and, at a minimum, a subset of the analogs.


Assuntos
Doença de Chagas , Trypanosoma cruzi , Humanos , Proteínas de Transporte de Nucleosídeos , Tubercidina , Transporte Biológico , Doença de Chagas/tratamento farmacológico , Desoxiuridina
7.
Molecules ; 27(22)2022 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-36432189

RESUMO

Chagas disease, caused by Trypanosoma cruzi (T. cruzi), is a serious public health problem. Current treatment is restricted to two drugs, benznidazole and nifurtimox, displaying serious efficacy and safety drawbacks. Nucleoside analogues represent a promising alternative as protozoans do not biosynthesize purines and rely on purine salvage from the hosts. Protozoan transporters often present different substrate specificities from mammalian transporters, justifying the exploration of nucleoside analogues as therapeutic agents. Previous reports identified nucleosides with potent trypanocidal activity; therefore, two 7-derivatized tubercidins (FH11706, FH10714) and a 3'-deoxytubercidin (FH8513) were assayed against T. cruzi. They were highly potent and selective, and the uptake of the tubercidin analogues appeared to be mediated by the nucleoside transporter TcrNT2. At 10 µM, the analogues reduced parasitemia >90% in 2D and 3D cardiac cultures. The washout assays showed that FH10714 sterilized the infected cultures. Given orally, the compounds did not induce noticeable mouse toxicity (50 mg/kg), suppressed the parasitemia of T. cruzi-infected Swiss mice (25 mg/kg, 5 days) and presented DNA amplification below the limit of detection. These findings justify further studies with longer treatment regimens, as well as evaluations in combination with nitro drugs, aiming to identify more effective and safer therapies for Chagas disease.


Assuntos
Doença de Chagas , Tripanossomicidas , Trypanosoma cruzi , Camundongos , Animais , Nucleosídeos/farmacologia , Nucleosídeos/uso terapêutico , Tripanossomicidas/farmacologia , Tripanossomicidas/uso terapêutico , Tripanossomicidas/química , Parasitemia/tratamento farmacológico , Doença de Chagas/tratamento farmacológico , Mamíferos
8.
PLoS Pathog ; 15(4): e1007697, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-31034512

RESUMO

Antibiotic susceptibility of bacterial pathogens is typically evaluated using in vitro assays that do not consider the complex host microenvironment. This may help explaining a significant discrepancy between antibiotic efficacy in vitro and in vivo, with some antibiotics being effective in vitro but not in vivo or vice versa. Nevertheless, it is well-known that antibiotic susceptibility of bacteria is driven by environmental factors. Lung epithelial cells enhance the activity of aminoglycoside antibiotics against the opportunistic pathogen Pseudomonas aeruginosa, yet the mechanism behind is unknown. The present study addresses this gap and provides mechanistic understanding on how lung epithelial cells stimulate aminoglycoside activity. To investigate the influence of the local host microenvironment on antibiotic activity, an in vivo-like three-dimensional (3-D) lung epithelial cell model was used. We report that conditioned medium of 3-D lung cells, containing secreted but not cellular components, potentiated the bactericidal activity of aminoglycosides against P. aeruginosa, including resistant clinical isolates, and several other pathogens. In contrast, conditioned medium obtained from the same cell type, but grown as conventional (2-D) monolayers did not influence antibiotic efficacy. We found that 3-D lung cells secreted endogenous metabolites (including succinate and glutamate) that enhanced aminoglycoside activity, and provide evidence that bacterial pyruvate metabolism is linked to the observed potentiation of antimicrobial activity. Biochemical and phenotypic assays indicated that 3-D cell conditioned medium stimulated the proton motive force (PMF), resulting in increased bacterial intracellular pH. The latter stimulated antibiotic uptake, as determined using fluorescently labelled tobramycin in combination with flow cytometry analysis. Our findings reveal a cross-talk between host and bacterial metabolic pathways, that influence downstream activity of antibiotics. Understanding the underlying basis of the discrepancy between the activity of antibiotics in vitro and in vivo may lead to improved diagnostic approaches and pave the way towards novel means to stimulate antibiotic activity.


Assuntos
Meios de Cultivo Condicionados/farmacologia , Pulmão/metabolismo , Metaboloma , Força Próton-Motriz/efeitos dos fármacos , Infecções por Pseudomonas/tratamento farmacológico , Pseudomonas aeruginosa/efeitos dos fármacos , Tobramicina/farmacologia , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Células Cultivadas , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Células Epiteliais/microbiologia , Humanos , Pulmão/efeitos dos fármacos , Pulmão/microbiologia , Testes de Sensibilidade Microbiana , Infecções por Pseudomonas/metabolismo , Infecções por Pseudomonas/microbiologia
9.
J Biol Chem ; 294(35): 12947-12956, 2019 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-31296659

RESUMO

Natural killer T (NKT) cells are a subset of T lymphocytes that recognize glycolipid antigens presented by the CD1d molecule (CD1d). They rapidly respond to antigen challenge and can activate both innate and adaptive immune cells. To study the role of antigen presentation in NKT cell activation, previous studies have developed several anti-CD1d antibodies that block CD1d binding to T-cell receptors (TCRs). Antibodies that are specific to both CD1d and the presented antigen can only be used to study the function of only a limited number of antigens. In contrast, antibodies that bind CD1d and block TCR binding regardless of the presented antigen can be widely used to assess the role of TCR-mediated NKT cell activation in various disease models. Here, we report the crystal structure of the widely used anti-mouse CD1d antibody 1B1 bound to CD1d at a resolution of 2.45 Å and characterized its binding to CD1d-presented glycolipids. We observed that 1B1 uses a long hydrophobic H3 loop that is inserted deep into the binding groove of CD1d where it makes intimate nonpolar contacts with the lipid backbone of an incorporated spacer lipid. Using an NKT cell agonist that has a modified sphingosine moiety, we further demonstrate that 1B1 in its monovalent form cannot block TCR-mediated NKT cell activation, because 1B1 fails to bind with high affinity to mCD1d. Our results suggest potential limitations of using 1B1 to assess antigen recognition by NKT cells, especially when investigating antigens that do not follow the canonical two alkyl-chain rule.


Assuntos
Anticorpos Monoclonais/imunologia , Antígenos CD1d/imunologia , Células T Matadoras Naturais/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Animais , Reações Antígeno-Anticorpo , Antígenos CD1d/isolamento & purificação , Camundongos , Receptores de Antígenos de Linfócitos T/química , Células Tumorais Cultivadas
10.
J Biol Chem ; 294(39): 14345-14356, 2019 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-31391251

RESUMO

Type I natural killer T (NKT) cells are a population of innate like T lymphocytes that rapidly respond to α-GalCer presented by CD1d via the production of both pro- and anti-inflammatory cytokines. While developing novel α-GalCer analogs that were meant to be utilized as potential adjuvants because of their production of pro-inflammatory cytokines (Th1 skewers), we generated α-galactosylsphingamides (αGSA). Surprisingly, αGSAs are not potent antigens in vivo despite their strong T-cell receptor (TCR)-binding affinities. Here, using surface plasmon resonance (SPR), antigen presentation assays, and X-ray crystallography (yielding crystal structures of 19 different binary (CD1d-glycolipid) or ternary (CD1d-glycolipid-TCR) complexes at resolutions between 1.67 and 2.85 Å), we characterized the biochemical and structural details of αGSA recognition by murine NKT cells. We identified a molecular switch within murine (m)CD1d that modulates NKT cell activation by αGSAs. We found that the molecular switch involves a hydrogen bond interaction between Tyr-73 of mCD1d and the amide group oxygen of αGSAs. We further established that the length of the acyl chain controls the positioning of the amide group with respect to the molecular switch and works synergistically with Tyr-73 to control NKT cell activity. In conclusion, our findings reveal important mechanistic insights into the presentation and recognition of glycolipids with polar moieties in an otherwise apolar milieu. These observations may inform the development αGSAs as specific NKT cell antagonists to modulate immune responses.


Assuntos
Antígenos CD1d/química , Glicoesfingolipídeos/química , Células Matadoras Naturais/imunologia , Simulação de Dinâmica Molecular , Animais , Antígenos CD1d/metabolismo , Sítios de Ligação , Glicoesfingolipídeos/metabolismo , Ligação de Hidrogênio , Ativação Linfocitária , Camundongos , Oxigênio/química , Ligação Proteica , Receptores de Antígenos de Linfócitos T/química , Receptores de Antígenos de Linfócitos T/metabolismo , Células Sf9 , Spodoptera
11.
Biomacromolecules ; 21(2): 793-802, 2020 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-31829561

RESUMO

Synthetic materials capable of engineering the immune system are of great relevance in the fight against cancer to replace or complement the current monoclonal antibody and cell therapy-based immunotherapeutics. Here, we report on antibody recruiting glycopolymers (ARGPs). ARGPs consist of polymeric copies of a rhamnose motif, which can bind endogenous antirhamnose antibodies present in human serum. As a proof-of-concept, we have designed ARGPs with a lipophilic end group that efficiently inserts into cell-surface membranes. We validate the specificity of rhamnose to attract antibodies from human serum to the target cell surface and demonstrate that ARGPs outperform an analogous small-molecule compound containing only one single rhamnose motif. The ARGP concept opens new avenues for the design of potent immunotherapeutics that mark target cells for destruction by the immune system through antibody-mediated effector functions.


Assuntos
Anticorpos Monoclonais/metabolismo , Formação de Anticorpos/fisiologia , Polímeros/metabolismo , Receptores de Superfície Celular/metabolismo , Ramnose/metabolismo , Adolescente , Adulto , Idoso , Anticorpos Monoclonais/química , Linhagem Celular Tumoral , Feminino , Humanos , Células Jurkat , Masculino , Pessoa de Meia-Idade , Polímeros/química , Ligação Proteica/fisiologia , Receptores de Superfície Celular/química , Ramnose/química , Adulto Jovem
12.
J Enzyme Inhib Med Chem ; 35(1): 1503-1512, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32657203

RESUMO

Metachromatic leukodystrophy (MLD) is a rare genetic disease characterised by a dysfunction of the enzyme arylsulphatase A leading to the lysosomal accumulation of cerebroside sulphate (sulphatide) causing subsequent demyelination in patients. The enzyme galactosylceramide (cerebroside) sulphotransferase (CST) catalyses the transfer of a sulphate group from 3'-phosphoadenosine-5'-phosphosulphate (PAPS) to cerebrosides producing sulphatides. Substrate reduction therapy for arylsulphatase A by inhibition of CST was proposed as a promising therapeutic approach. To identify competitive CST inhibitors, we synthesised and investigated analogues of the substrate galactosylceramide with variations at the anomeric position, the acyl substituent and the carbohydrate moiety, and investigated their structure-activity relationships. While most of the compounds behaved as substrates, α-galactosylceramide 16 was identified as the first competitive CST inhibitor. Compound 16 can serve as a new lead structure for the development of drugs for the treatment of this devastating disease, MLD, for which small molecule therapeutics are currently not available.


Assuntos
Cerebrosídeos/farmacologia , Descoberta de Drogas , Leucodistrofia Metacromática/tratamento farmacológico , Sulfotransferases/antagonistas & inibidores , Cerebrosídeos/síntese química , Cerebrosídeos/química , Relação Dose-Resposta a Droga , Humanos , Leucodistrofia Metacromática/enzimologia , Estrutura Molecular , Relação Estrutura-Atividade , Especificidade por Substrato/efeitos dos fármacos , Sulfotransferases/genética , Sulfotransferases/metabolismo
13.
J Labelled Comp Radiopharm ; 63(10): 442-455, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32472945

RESUMO

The metabolic alterations in tumors make it possible to visualize the latter by means of positron emission tomography, enabling diagnosis and providing metabolic information. The alanine serine cysteine transporter-2 (ASCT-2) is the main transporter of glutamine and is upregulated in several tumors. Therefore, a good positron emission tracer targeting this transport protein would have substantial value. Hence, the aim of this study is to develop a fluorine-18-labeled version of a V-9302 analogue, one of the most potent inhibitors of ASCT-2. The precursor was labeled with fluorine-18 via a nucleophilic substitution of the corresponding benzylic bromide. The cold reference product was subjected to in vitro assays with [3 H]glutamine in a PC-3 and F98 cell line to determine the affinity for both the human and rat ASCT-2. To evaluate the tracer potential dynamic µPET, images were acquired in a mouse xenograft model for prostate cancer. The tracer could be synthesized with an overall nondecay corrected yield of 3.66 ± 1.90%. in vitro experiments show inhibitor constants Ki of 90 and 125 µM for the PC-3 and F98 cells, respectively. The experiments in the PC-3 xenograft demonstrate a low uptake in the tumor tissue. We have successfully synthesized the radiotracer [18 F]2-amino-4-((2-((3-fluorobenzyl)oxy)benzyl)(2-((3-(fluoromethyl)benzyl)oxy)benzyl)amino)butanoic acid. in vitro experiments show a good affinity for both the human and rat ASCT-2. However, the tracer suffers from poor in vivo tumor uptake in the PC-3 model. Briefly, we present the first fluorine-18-labeled derivative of compound V-9302, a promising novel ASCT-2 blocker used for inhibition of tumor growth.


Assuntos
Ácido Butírico/química , Ácido Butírico/síntese química , Tomografia por Emissão de Pósitrons , Animais , Ácido Butírico/farmacologia , Linhagem Celular Tumoral , Masculino , Camundongos , Ratos
14.
Molecules ; 25(7)2020 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-32230915

RESUMO

In recent years, new drug discovery approaches based on novel pharmacological concepts have emerged. Allosteric modulators, for example, target receptors at sites other than the orthosteric binding sites and can modulate agonist-mediated activation. Interestingly, allosteric regulation may allow a fine-tuned regulation of unbalanced neurotransmitter' systems, thus providing safe and effective treatments for a number of central nervous system diseases. The metabotropic glutamate type 5 receptor (mGlu5R) has been shown to possess a druggable allosteric binding domain. Accordingly, novel allosteric ligands are being explored in order to finely regulate glutamate neurotransmission, especially in the brain. However, before testing the activity of these new ligands in the clinic or even in animal disease models, it is common to characterize their ability to bind mGlu5Rs in vitro. Here, we have developed a new series of fluorescent ligands that, when used in a new NanoBRET-based binding assay, will facilitate screening for novel mGlu5R allosteric modulators.


Assuntos
Descoberta de Drogas/métodos , Corantes Fluorescentes/química , Receptor de Glutamato Metabotrópico 5/química , Regulação Alostérica/efeitos dos fármacos , Sítio Alostérico , Sítios de Ligação , Técnicas de Transferência de Energia por Ressonância de Bioluminescência , Compostos de Boro/síntese química , Compostos de Boro/química , Cálcio/metabolismo , Descoberta de Drogas/instrumentação , Células HEK293 , Humanos , Ligantes , Porfobilinogênio/análogos & derivados , Porfobilinogênio/química , Ligação Proteica , Receptor de Glutamato Metabotrópico 5/genética , Receptor de Glutamato Metabotrópico 5/metabolismo
15.
Molecules ; 25(12)2020 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-32560578

RESUMO

A series of Mycobacterium tuberculosis TMPK (MtbTMPK) inhibitors based on a reported compound 3 were synthesized and evaluated for their capacity to inhibit MtbTMPK catalytic activity and the growth of a virulent M. tuberculosis strain (H37Rv). Modifications of the scaffold of 3 failed to afford substantial improvements in MtbTMPK inhibitory activity and antimycobacterial activity. Optimization of the substitution pattern of the D ring of 3 resulted in compound 21j with improved MtbTMPK inhibitory potency (three-fold) and H37Rv growth inhibitory activity (two-fold). Moving the 3-chloro substituent of 21j to the para-position afforded isomer 21h, which, despite a 10-fold increase in IC50-value, displayed promising whole cell activity (minimum inhibitory concentration (MIC) = 12.5 µM).


Assuntos
Antituberculosos , Proteínas de Bactérias/antagonistas & inibidores , Inibidores Enzimáticos , Mycobacterium tuberculosis/enzimologia , Núcleosídeo-Fosfato Quinase/antagonistas & inibidores , Timina , Antituberculosos/síntese química , Antituberculosos/química , Antituberculosos/farmacologia , Proteínas de Bactérias/metabolismo , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Humanos , Modelos Moleculares , Estrutura Molecular , Núcleosídeo-Fosfato Quinase/metabolismo , Relação Estrutura-Atividade , Timina/análogos & derivados , Timina/síntese química , Timina/química , Timina/farmacologia
16.
Bioorg Med Chem Lett ; 29(10): 1232-1235, 2019 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-30879839

RESUMO

A series of eleven double prodrug derivatives of a fosmidomycin surrogate were synthesized and investigated for their ability to inhibit in vitro growth of P. falciparum and M. tuberculosis. A pivaloyloxymethyl (POM) phosphonate prodrug modification was combined with various prodrug derivatisations of the hydroxamate moiety. The majority of compounds showed activity comparable with or inferior to fosmidomycin against P. falciparum. N-benzyl substituted carbamate prodrug 6f was the most active antimalarial analog with an IC50 value of 0.64 µM. Contrary to fosmidomycin and parent POM-prodrug 5, 2-nitrofuran and 2-nitrothiophene prodrugs 6i and 6j displayed promising antitubercular activities.


Assuntos
Antimaláricos/química , Antituberculosos/química , Mycobacterium tuberculosis/efeitos dos fármacos , Plasmodium falciparum/efeitos dos fármacos , Pró-Fármacos/química , Antimaláricos/farmacologia , Antituberculosos/farmacologia , Carbamatos/química , Avaliação Pré-Clínica de Medicamentos/métodos , Fosfomicina/análogos & derivados , Fosfomicina/farmacologia , Humanos , Concentração Inibidora 50 , Estrutura Molecular , Nitrofuranos/química , Pró-Fármacos/farmacologia , Transdução de Sinais , Relação Estrutura-Atividade
17.
Bioorg Med Chem Lett ; 29(9): 1051-1053, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30857749

RESUMO

A series of N-alkoxy analogs of a l-leucine ethyl ester phosphonodiamidate prodrug of a fosmidomycin surrogate were synthesized and investigated for their ability to inhibit in vitro growth of P. falciparum and M. tuberculosis. These compounds originate by merging a previously reported successful phosphonate derivatisation with favorable modifications of the hydroxamate moiety. None of the synthesized compounds showed enhanced activity against either P. falciparum or M. tuberculosis in comparison with the parent free hydroxamate analog.


Assuntos
Antimaláricos/química , Antituberculosos/química , Fosfomicina/análogos & derivados , Organofosfonatos/química , Pró-Fármacos/química , Antimaláricos/síntese química , Antimaláricos/farmacologia , Antituberculosos/síntese química , Antituberculosos/farmacologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Fosfomicina/química , Humanos , Ácidos Hidroxâmicos/química , Mycobacterium tuberculosis/efeitos dos fármacos , Plasmodium falciparum/efeitos dos fármacos , Pró-Fármacos/síntese química , Pró-Fármacos/farmacologia
18.
Bioorg Med Chem ; 27(5): 729-747, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30692024

RESUMO

Fosmidomycin is a natural antibiotic with promising IspC (DXR, 1-deoxy-d-xylulose-5-phosphate reductoisomerase) inhibitory activity. This enzyme catalyzes the first committed step of the non-mevalonate isoprenoid biosynthesis pathway, which is essential in Plasmodium falciparum and Mycobacterium tuberculosis. Mainly as a result of its high polarity, fosmidomycin displays suboptimal pharmacokinetic properties. Furthermore, fosmidomycin is inactive against M. tuberculosis as a result of its inability to penetrate the bacterial cell wall. Temporarily masking the phosphonate moiety as a prodrug has the potential to solve both issues. We report the application of two amino acid based prodrug approaches on a fosmidomycin surrogate. Conversion of the phosphonate moiety into tyrosine-derived esters increases the in vitro activity against asexual blood stages of P. falciparum, while phosphonodiamidate prodrugs display promising antitubercular activities. Selected prodrugs were tested in vivo in a P. berghei malaria mouse model. These results indicate good in vivo antiplasmodial potential.


Assuntos
Aminoácidos/farmacologia , Antimaláricos/farmacologia , Antituberculosos/farmacologia , Fosfomicina/análogos & derivados , Pró-Fármacos/farmacologia , Aminoácidos/síntese química , Aminoácidos/toxicidade , Animais , Antimaláricos/síntese química , Antimaláricos/toxicidade , Antituberculosos/síntese química , Antituberculosos/toxicidade , Linhagem Celular , Feminino , Fosfomicina/síntese química , Fosfomicina/farmacologia , Fosfomicina/toxicidade , Humanos , Camundongos , Testes de Sensibilidade Microbiana , Mycobacterium tuberculosis/efeitos dos fármacos , Plasmodium berghei/efeitos dos fármacos , Plasmodium falciparum/efeitos dos fármacos , Pró-Fármacos/síntese química , Pró-Fármacos/toxicidade
19.
J Immunol ; 199(1): 97-106, 2017 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-28526683

RESUMO

Invariant NKT (iNKT) cells are innate-like lymphocytes that recognize lipid Ags presented by CD1d. The prototypical Ag, α-galactosylceramide, strongly activates human and mouse iNKT cells, leading to the assumption that iNKT cell physiology in human and mouse is similar. In this article, we report the surprising finding that human, but not mouse, iNKT cells directly recognize myelin-derived sulfatide presented by CD1d. We propose that sulfatide is recognized only by human iNKT cells because of the unique positioning of the 3-O-sulfated ß-galactose headgroup. Surface plasmon resonance shows that the affinity of human CD1d-sulfatide for the iNKT cell receptor is relatively low compared with CD1d-α-galactosylceramide (KD of 19-26 µM versus 1 µM). Apolipoprotein E isolated from human cerebrospinal fluid carries sulfatide that can be captured by APCs and presented by CD1d to iNKT cells. APCs from patients with metachromatic leukodystrophy, who accumulate sulfatides due to a deficiency in arylsulfatase-A, directly activate iNKT cells. Thus, we have identified sulfatide as a self-lipid recognized by human iNKT cells and propose that sulfatide recognition by innate T cells may be an important pathologic feature of neuroinflammatory disease and that sulfatide in APCs may contribute to the endogenous pathway of iNKT cell activation.


Assuntos
Apresentação de Antígeno , Ativação Linfocitária , Células T Matadoras Naturais/imunologia , Sulfoglicoesfingolipídeos/imunologia , Animais , Antígenos CD1d/imunologia , Apolipoproteínas E/líquido cefalorraquidiano , Apolipoproteínas E/química , Apolipoproteínas E/imunologia , Linhagem Celular , Cerebrosídeo Sulfatase/deficiência , Cerebrosídeo Sulfatase/metabolismo , Galactosilceramidas/imunologia , Humanos , Leucodistrofia Metacromática/imunologia , Camundongos , Células T Matadoras Naturais/fisiologia , Receptores de Antígenos de Linfócitos T/imunologia , Ressonância de Plasmônio de Superfície , Subpopulações de Linfócitos T/imunologia
20.
J Enzyme Inhib Med Chem ; 34(1): 1730-1739, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31822127

RESUMO

A series of readily accessible 1-(piperidin-3-yl)thymine amides was designed, synthesised and evaluated as Mycobacterium tuberculosis TMPK (MtbTMPK) inhibitors. In line with the modelling results, most inhibitors showed reasonable MtbTMPK inhibitory activity. Compounds 4b and 4i were slightly more potent than the parent compound 3. Moreover, contrary to the latter, amide analogue 4g was active against the avirulent M. tuberculosis H37Ra strain (MIC50=35 µM). This finding opens avenues for future modifications.


Assuntos
Amidas/farmacologia , Antituberculosos/farmacologia , Inibidores Enzimáticos/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Núcleosídeo-Fosfato Quinase/antagonistas & inibidores , Timina/farmacologia , Amidas/síntese química , Amidas/química , Antituberculosos/síntese química , Antituberculosos/química , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Mycobacterium tuberculosis/enzimologia , Núcleosídeo-Fosfato Quinase/metabolismo , Relação Estrutura-Atividade , Timina/síntese química , Timina/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA