RESUMO
Human dihydroorotate dehydrogenase (hDHODH) is an enzyme belonging to a flavin mononucleotide (FMN)-dependent family involved in de novo pyrimidine biosynthesis, a key biological pathway for highly proliferating cancer cells and pathogens. In fact, hDHODH proved to be a promising therapeutic target for the treatment of acute myelogenous leukemia, multiple myeloma, and viral and bacterial infections; therefore, the identification of novel hDHODH ligands represents a hot topic in medicinal chemistry. In this work, we reported a virtual screening study for the identification of new promising hDHODH inhibitors. A pharmacophore-based approach combined with a consensus docking analysis and molecular dynamics simulations was applied to screen a large database of commercial compounds. The whole virtual screening protocol allowed for the identification of a novel compound that is endowed with promising inhibitory activity against hDHODH and is structurally different from known ligands. These results validated the reliability of the in silico workflow and provided a valuable starting point for hit-to-lead and future lead optimization studies aimed at the development of new potent hDHODH inhibitors.
Assuntos
Oxirredutases atuantes sobre Doadores de Grupo CH-CH , Di-Hidro-Orotato Desidrogenase , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/química , Humanos , Ligantes , Simulação de Acoplamento Molecular , Receptores de Droga , Reprodutibilidade dos TestesRESUMO
Dihydroorotate dehydrogenase (DHODH), an enzyme that plays a critical role in the de novo pyrimidine biosynthesis, has been recognized as a promising target for the treatment of diseases that involve cellular proliferation, such as autoimmune diseases and cancers. Pharmacological inhibition of human DHODH (hDHODH) that offers a potential therapeutic strategy for the treatment in adult subjects with acute myeloid leukemia (AML) has recently been supported by phase I/II clinical trials for the treatment of patients with relapsed/refractory AML. To facilitate the development of optimized hDHODH inhibitors, the presence of an in vivo imaging probe that is able to demonstrate in vivo target engagement is critical and desirable. Brequinar is one of the most potent hDHODH inhibitors so far discovered. In this work, we use a copper-mediated radiofluorination (CMRF) strategy and compare the chemical design and radiosynthesis starting from either pinacole boronate p-nitrobenzyl ester (4) or tributylstannate (tin) p-nitrobenzyl ester (5), chosen for their suitability as a precursor to [18F]brequinar. We report here the design, synthesis, radiolabeling and characterization of [18F]brequinar, and a preliminary PET imaging study of DHODH in vivo. This study provides the strategies to create [18F]brequinar, the first hDHODH inhibitor PET radiotracer, which will facilitate its use as a tool (theranostics) for hDHODH drug development and for diagnosis and monitoring therapeutic efficacy in AML and cancers.
RESUMO
Over the years, human dihydroorotate dehydrogenase (hDHODH), which is a key player in the de novo pyrimidine-biosynthesis pathway, has been targeted in the treatment of several conditions, including autoimmune disorders and acute myelogenous leukaemia, as well as in host-targeted antiviral therapy. A molecular exploration of its inhibitor-binding behaviours yielded promising candidates for innovative drug design. A detailed description of the enzymatic pharmacophore drove the decoration of well-established inhibitory scaffolds, thus gaining further in vitro and in vivo efficacy. In the present work, using X-ray crystallography, an atypical rearrangement was identified in the binding pose of a potent inhibitor characterized by a polar pyridine-based moiety (compound 18). The crystal structure shows that upon binding compound 18 the dynamics of a protein loop involved in a gating mechanism at the cofactor-binding site is modulated by the presence of three water molecules, thus fine-tuning the polarity/hydrophobicity of the binding pocket. These solvent molecules are engaged in the formation of a hydrogen-bond mesh in which one of them establishes a direct contact with the pyridine moiety of compound 18, thus paving the way for a reappraisal of the inhibition of hDHODH. Using an integrated approach, the thermodynamics of such a modulation is described by means of isothermal titration calorimetry coupled with molecular modelling. These structural insights will guide future drug design to obtain a finer Kd/logD7.4 balance and identify membrane-permeable molecules with a drug-like profile in terms of water solubility.
Assuntos
Di-Hidro-Orotato Desidrogenase , Oxirredutases atuantes sobre Doadores de Grupo CH-CH , Humanos , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/química , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/antagonistas & inibidores , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/metabolismo , Cristalografia por Raios X/métodos , Sítios de Ligação , Piridinas/química , Piridinas/farmacologia , Conformação Proteica , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Modelos Moleculares , Ligação Proteica , Ligação de HidrogênioRESUMO
AKR1C3 is an enzyme that is overexpressed in several types of radiotherapy- and chemotherapy-resistant cancers. Despite AKR1C3 is a validated target for drug development, no inhibitor has been approved for clinical use. In this manuscript, we describe our study of a new series of potent AKR1C3-targeting 3-hydroxybenzoisoxazole based inhibitors that display high selectivity over the AKR1C2 isoform and low micromolar activity in inhibiting 22Rv1 prostate cancer cell proliferation. In silico studies suggested proper substituents to increase compound potency and provided with a mechanistic explanation that could clarify their different activity, later confirmed by X-ray crystallography. Both the in-silico studies and the crystallographic data highlight the importance of 90° rotation around the single bond of the biphenyl group, in ensuring that the inhibitor can adopt the optimal binding mode within the active pocket. The p-biphenyls that bear the meta-methoxy, and the ortho- and meta-trifluoromethyl substituents (in compounds 6a, 6e and 6f respectively) proved to be the best contributors to cellular potency as they provided the best IC50 values in series (2.3, 2.0 and 2.4 µM respectively) and showed no toxicity towards human MRC-5 cells. Co-treatment with scalar dilutions of either compound 6 or 6e and the clinically used drug abiraterone led to a significant reduction in cell proliferation, and thus confirmed that treatment with both CYP171A1-and AKR1C3-targeting compounds possess the potential to intervene in key steps in the steroidogenic pathway. Taken together, the novel compounds display desirable biochemical potency and cellular target inhibition as well as good in-vitro ADME properties, which highlight their potential for further preclinical studies.
Assuntos
Neoplasias da Próstata , Masculino , Humanos , Membro C3 da Família 1 de alfa-Ceto Redutase , Neoplasias da Próstata/tratamento farmacológico , 3-Hidroxiesteroide Desidrogenases/metabolismo , Hidroxiprostaglandina Desidrogenases/metabolismo , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/químicaRESUMO
Mycobacterium tuberculosis (MTB) is the etiologic agent of tuberculosis (TB), an ancient disease which causes 1.5 million deaths worldwide. Dihydroorotate dehydrogenase (DHODH) is a key enzyme of the MTB de novo pyrimidine biosynthesis pathway, and it is essential for MTB growth in vitro, hence representing a promising drug target. We present: (i) the biochemical characterization of the full-length MTB DHODH, including the analysis of the kinetic parameters, and (ii) the previously unreleased crystal structure of the protein that allowed us to rationally screen our in-house chemical library and identify the first selective inhibitor of mycobacterial DHODH. The inhibitor has fluorescence properties, potentially instrumental to in cellulo imaging studies, and exhibits an IC50 value of 43 µm, paving the way to hit-to-lead process.
Assuntos
Mycobacterium tuberculosis , Oxirredutases atuantes sobre Doadores de Grupo CH-CH , Tuberculose , Humanos , Di-Hidro-Orotato Desidrogenase , Mycobacterium tuberculosis/metabolismo , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/química , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/metabolismo , Sistemas de Liberação de Medicamentos , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/químicaRESUMO
Human respiratory syncytial virus (RSV) is an important cause of acute lower respiratory infections, for which no effective drugs are currently available. The development of new effective anti-RSV agents is therefore an urgent priority, and Host-Targeting Antivirals (HTAs) can be considered to target RSV infections. As a contribution to this antiviral avenue, we have characterized the molecular mechanisms of the anti-RSV activity of MEDS433, a new inhibitor of human dihydroorotate dehydrogenase (hDHODH), a key cellular enzyme of de novo pyrimidine biosynthesis. MEDS433 was found to exert a potent antiviral activity against RSV-A and RSV-B in the one-digit nanomolar range. Analysis of the RSV replication cycle in MEDS433-treated cells, revealed that the hDHODH inhibitor suppressed the synthesis of viral genome, consistently with its ability to specifically target hDHODH enzymatic activity. Then, the capability of MEDS433 to induce the expression of antiviral proteins encoded by Interferon-Stimulated Genes (ISGs) was identified as a second mechanism of its antiviral activity against RSV. Indeed, MEDS433 stimulated secretion of IFN-ß and IFN-λ1 that, in turn, induced the expression of some ISG antiviral proteins, such as IFI6, IFITM1 and IRF7. Singly expression of these ISG proteins reduced RSV-A replication, thus likely contributing to the overall anti-RSV activity of MEDS433. Lastly, MEDS433 proved to be effective against RSV-A replication even in a primary human small airway epithelial cell model. Taken as a whole, these observations provide new insights for further development of MEDS433, as a promising candidate to develop new strategies for treatment of RSV infections.
Assuntos
Infecções por Vírus Respiratório Sincicial , Vírus Sincicial Respiratório Humano , Humanos , Infecções por Vírus Respiratório Sincicial/tratamento farmacológico , Interferons/farmacologia , Proteínas , Antivirais/farmacologia , Antivirais/uso terapêutico , Replicação ViralRESUMO
The pharmacological management of influenza virus (IV) infections still poses a series of challenges due to the limited anti-IV drug arsenal. Therefore, the development of new anti-influenza agents effective against antigenically different IVs is therefore an urgent priority. To meet this need, host-targeting antivirals (HTAs) can be evaluated as an alternative or complementary approach to current direct-acting agents (DAAs) for the therapy of IV infections. As a contribution to this antiviral strategy, in this study, we characterized the anti-IV activity of MEDS433, a novel small molecule inhibitor of the human dihydroorotate dehydrogenase (hDHODH), a key cellular enzyme of the de novo pyrimidine biosynthesis pathway. MEDS433 exhibited a potent antiviral activity against IAV and IBV replication, which was reversed by the addition of exogenous uridine and cytidine or the hDHODH product orotate, thus indicating that MEDS433 targets notably hDHODH activity in IV-infected cells. When MEDS433 was used in combination either with dipyridamole (DPY), an inhibitor of the pyrimidine salvage pathway, or with an anti-IV DAA, such as N4-hydroxycytidine (NHC), synergistic anti-IV activities were observed. As a whole, these results indicate MEDS433 as a potential HTA candidate to develop novel anti-IV intervention approaches, either as a single agent or in combination regimens with DAAs.
Assuntos
Influenza Humana , Infecções por Orthomyxoviridae , Humanos , Antivirais/farmacologia , Replicação Viral , Pirimidinas/farmacologia , Inibidores Enzimáticos/farmacologia , Uridina/farmacologia , Di-Hidro-Orotato Desidrogenase , Dipiridamol/farmacologia , Citidina/farmacologiaRESUMO
The aldo-keto reductase 1C3 (AKR1C3) enzyme is considered an attractive target in Castration Resistant Prostate Cancer (CRPC) because of its role in the biosynthesis of androgens. Flufenamic acid, a non-selective AKR1C3 inhibitor, has previously been subjected to bioisosteric modulation to give rise to a series of compounds with the hydroxytriazole core. In this work, the hit compound of the previous series has been modulated further, and new, more potent, and selective derivatives have been obtained. The poor solubility of the most active compound (cpd 5) has been improved by substituting the triazole core with an isoxazole heteronucleous, with similar enzymatic activity being retained. Potent AKR1C3 inhibition is translated into antiproliferative effects against the 22RV1 CRPC cellular model, and the in-silico design, synthesis and biological activity of new compounds are described herein. Compounds have also been assayed in combination with two approved antitumor drugs, abiraterone and enzalutamide.
Assuntos
Membro C3 da Família 1 de alfa-Ceto Redutase , Antineoplásicos , Inibidores Enzimáticos , Neoplasias de Próstata Resistentes à Castração , Membro C3 da Família 1 de alfa-Ceto Redutase/antagonistas & inibidores , Androgênios , Antineoplásicos/química , Antineoplásicos/farmacologia , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Humanos , Masculino , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológicoRESUMO
In recent years, human dihydroorotate dehydrogenase inhibitors have been associated with acute myelogenous leukemia as well as studied as potent host targeting antivirals. Starting from MEDS433 (IC50 1.2 nM), we kept improving the structure-activity relationship of this class of compounds characterized by 2-hydroxypyrazolo[1,5-a]pyridine scaffold. Using an in silico/crystallography supported design, we identified compound 4 (IC50 7.2 nM), characterized by the presence of a decorated aryloxyaryl moiety that replaced the biphenyl scaffold, with potent inhibition and pro-differentiating abilities on AML THP1 cells (EC50 74 nM), superior to those of brequinar (EC50 249 nM) and boosted when in combination with dipyridamole. Finally, compound 4 has an extremely low cytotoxicity on non-AML cells as well as MEDS433; it has shown a significant antileukemic activity in vivo in a xenograft mouse model of AML.
Assuntos
Leucemia Mieloide Aguda , Oxirredutases atuantes sobre Doadores de Grupo CH-CH , Animais , Humanos , Camundongos , Antivirais/farmacologia , Di-Hidro-Orotato Desidrogenase , Dipiridamol/uso terapêutico , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Leucemia Mieloide Aguda/tratamento farmacológico , Piridinas/farmacologia , Piridinas/uso terapêutico , Relação Estrutura-AtividadeRESUMO
The development of different generations of BCR-ABL1 tyrosine kinase inhibitors (TKIs) has led to the high overall survival of chronic myeloid leukemia (CML) patients. However, there are CML patients who show resistance to TKI therapy and are prone to progress to more advanced phases of the disease. So, implementing an alternative approach for targeting TKIs insensitive cells would be of the essence. Dihydroorotate dehydrogenase (DHODH) is an enzyme in the de novo pyrimidine biosynthesis pathway that is located in the inner membrane of mitochondria. Here, we found that CML cells are vulnerable to DHODH inhibition mediated by Meds433, a new and potent DHODH inhibitor recently developed by our group. Meds433 significantly activates the apoptotic pathway and leads to the reduction of amino acids and induction of huge metabolic stress in CML CD34+ cells. Altogether, our study shows that DHODH inhibition is a promising approach for targeting CML stem/progenitor cells and may help more patients discontinue the therapy.
Assuntos
Di-Hidro-Orotato Desidrogenase , Leucemia Mielogênica Crônica BCR-ABL Positiva , Resistencia a Medicamentos Antineoplásicos , Proteínas de Fusão bcr-abl/metabolismo , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Inibidores de Proteínas Quinases/farmacologiaRESUMO
Emergence of drug resistance and adverse effects often affect the efficacy of nucleoside analogues in the therapy of Herpes simplex type 1 (HSV-1) and type 2 (HSV-2) infections. Host-targeting antivirals could therefore be considered as an alternative or complementary strategy in the management of HSV infections. To contribute to this advancement, here we report on the ability of a new generation inhibitor of a key cellular enzyme of de novo pyrimidine biosynthesis, the dihydroorotate dehydrogenase (DHODH), to inhibit HSV-1 and HSV-2 in vitro replication, with a potency comparable to that of the reference drug acyclovir. Analysis of the HSV replication cycle in MEDS433-treated cells revealed that it prevented the accumulation of viral genomes and reduced late gene expression, thus suggesting an impairment at a stage prior to viral DNA replication consistent with the ability of MEDS433 to inhibit DHODH activity. In fact, the anti-HSV activity of MEDS433 was abrogated by the addition of exogenous uridine or of the product of DHODH, the orotate, thus confirming DHODH as the MEDS433 specific target in HSV-infected cells. A combination of MEDS433 with dipyridamole (DPY), an inhibitor of the pyrimidine salvage pathway, was then observed to be effective in inhibiting HSV replication even in the presence of exogenous uridine, thus mimicking in vivo conditions. Finally, when combined with acyclovir and DPY in checkerboard experiments, MEDS433 exhibited highly synergistic antiviral activity. Taken together, these findings suggest that MEDS433 is a promising candidate as either single agent or in combination regimens with existing direct-acting anti-HSV drugs to develop new strategies for treatment of HSV infections.
Assuntos
Antivirais/farmacologia , Inibidores Enzimáticos/farmacologia , Herpes Simples/tratamento farmacológico , Herpesvirus Humano 1/efeitos dos fármacos , Herpesvirus Humano 2/efeitos dos fármacos , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/antagonistas & inibidores , Replicação Viral/efeitos dos fármacos , Aciclovir/farmacologia , Animais , Linhagem Celular Tumoral , Chlorocebus aethiops , Replicação do DNA/efeitos dos fármacos , DNA Viral/biossíntese , Di-Hidro-Orotato Desidrogenase , Sinergismo Farmacológico , Quimioterapia Combinada , Regulação Viral da Expressão Gênica/efeitos dos fármacos , Herpes Simples/virologia , Humanos , Pirimidinas/biossíntese , Células VeroRESUMO
AIM: Nuclear factor kappa B (NF-κB) is known to play an important role in the inflammatory process which takes place after ischemic stroke. The major objective of the present study was to examine the effects of MEDS-23, a potent inhibitor of NF-κB, on clinical outcomes and brain inflammatory markers in post-ischemic stroke rats. MAIN METHODS: Initially, a Toxicity Experiment was performed to determine the appropriate dose of MEDS-23 for use in animals, as MEDS-23 was analyzed in vivo for the first time. We used the middle cerebral artery occlusion (MCAO) model for inducing ischemic stroke in rats. The effects of MEDS-23 (at 10 mg/kg, ip) on post-stroke outcomes (brain inflammation, fever, neurological deficits, mortality, and depression- and anxiety-like behaviours) was tested in several efficacy experiments. KEY FINDINGS: MEDS-23 was found to be safe and significantly reduced the severity of some adverse post-stroke outcomes such as fever and neurological deficits. Moreover, MEDS-23 significantly decreased prostaglandin E2 levels in the hypothalamus and hippocampus of post-stroke rats, but did not prominently alter the levels of interleukin-6 and tumor necrosis factor-α. SIGNIFICANCE: These results suggest that NF-κB inhibition is a potential therapeutic strategy for the treatment of ischemic stroke.
RESUMO
Although coronaviruses (CoVs) have long been predicted to cause zoonotic diseases and pandemics with high probability, the lack of effective anti-pan-CoVs drugs rapidly usable against the emerging SARS-CoV-2 actually prevented a promptly therapeutic intervention for COVID-19. Development of host-targeting antivirals could be an alternative strategy for the control of emerging CoVs infections, as they could be quickly repositioned from one pandemic event to another. To contribute to these pandemic preparedness efforts, here we report on the broad-spectrum CoVs antiviral activity of MEDS433, a new inhibitor of the human dihydroorotate dehydrogenase (hDHODH), a key cellular enzyme of the de novo pyrimidine biosynthesis pathway. MEDS433 inhibited the in vitro replication of hCoV-OC43 and hCoV-229E, as well as of SARS-CoV-2, at low nanomolar range. Notably, the anti-SARS-CoV-2 activity of MEDS433 against SARS-CoV-2 was also observed in kidney organoids generated from human embryonic stem cells. Then, the antiviral activity of MEDS433 was reversed by the addition of exogenous uridine or the product of hDHODH, the orotate, thus confirming hDHODH as the specific target of MEDS433 in hCoVs-infected cells. Taken together, these findings suggest MEDS433 as a potential candidate to develop novel drugs for COVID-19, as well as broad-spectrum antiviral agents exploitable for future CoVs threats.
RESUMO
Dihydroorotate Dehydrogenase (DHODH) is a key enzyme of the de novo pyrimidine biosynthesis, whose inhibition can induce differentiation and apoptosis in acute myeloid leukemia (AML). DHODH inhibitors had shown promising in vitro and in vivo activity on solid tumors, but their effectiveness was not confirmed in clinical trials, probably because cancer cells exploited the pyrimidine salvage pathway to survive. Here, we investigated the antileukemic activity of MEDS433, the DHODH inhibitor developed by our group, against AML. Learning from previous failures, we mimicked human conditions (performing experiments in the presence of physiological uridine plasma levels) and looked for synergic combinations to boost apoptosis, including classical antileukemic drugs and dipyridamole, a blocker of the pyrimidine salvage pathway. MEDS433 induced apoptosis in multiple AML cell lines, not only as a consequence of differentiation, but also directly. Its combination with antileukemic agents further increased the apoptotic rate, but when experiments were performed in the presence of physiological uridine concentrations, results were less impressive. Conversely, the combination of MEDS433 with dipyridamole induced metabolic lethality and differentiation in all AML cell lines; this extraordinary synergism was confirmed on AML primary cells with different genetic backgrounds and was unaffected by physiological uridine concentrations, predicting in human activity.
RESUMO
The connection with acute myelogenous leukemia (AML) of dihydroorotate dehydrogenase (hDHODH), a key enzyme in pyrimidine biosynthesis, has attracted significant interest from pharma as a possible AML therapeutic target. We recently discovered compound 1, a potent hDHODH inhibitor (IC50 = 1.2 nM), able to induce myeloid differentiation in AML cell lines (THP1) in the low nM range (EC50 = 32.8 nM) superior to brequinar's phase I/II clinical trial (EC50 = 265 nM). Herein, we investigate the 1 drug-like properties observing good metabolic stability and no toxic profile when administered at doses of 10 and 25 mg/kg every 3 days for 5 weeks (Balb/c mice). Moreover, in order to identify a backup compound, we investigate the SAR of this class of compounds. Inside the series, 17 is characterized by higher potency in inducing myeloid differentiation (EC50 = 17.3 nM), strong proapoptotic properties (EC50 = 20.2 nM), and low cytotoxicity toward non-AML cells (EC30(Jurkat) > 100 µM).
Assuntos
Compostos de Bifenilo/química , Inibidores Enzimáticos/química , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/antagonistas & inibidores , Pirazóis/química , Piridinas/química , Animais , Apoptose/efeitos dos fármacos , Sítios de Ligação , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Di-Hidro-Orotato Desidrogenase , Desenho de Fármacos , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Feminino , Meia-Vida , Humanos , Leucemia Mieloide Aguda/tratamento farmacológico , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Microssomos Hepáticos/metabolismo , Simulação de Acoplamento Molecular , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/metabolismo , Pirazóis/metabolismo , Pirazóis/farmacologia , Pirazóis/uso terapêutico , Piridinas/metabolismo , Piridinas/farmacologia , Piridinas/uso terapêutico , Ratos , Ratos Sprague-Dawley , Relação Estrutura-AtividadeRESUMO
Pyrimidines are essential for the cell survival and proliferation of living parasitic organisms, such as Helicobacter pylori, Plasmodium falciparum and Schistosoma mansoni, that are able to impact upon human health. Pyrimidine building blocks, in human cells, are synthesised via both de novo biosynthesis and salvage pathways, the latter of which is an effective way of recycling pre-existing nucleotides. As many parasitic organisms lack pyrimidine salvage pathways for pyrimidine nucleotides, blocking de novo biosynthesis is seen as an effective therapeutic means to selectively target the parasite without effecting the human host. Dihydroorotate dehydrogenase (DHODH), which is involved in the de novo biosynthesis of pyrimidines, is a validated target for anti-infective drug research. Recent advances in the DHODH microorganism field are discussed herein, as is the potential for the development of DHODH-targeted therapeutics.
Assuntos
Anti-Infecciosos , Inibidores Enzimáticos , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/antagonistas & inibidores , Pirimidinas , Animais , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Di-Hidro-Orotato Desidrogenase , Descoberta de Drogas , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Humanos , Plasmodium falciparum/efeitos dos fármacos , Pirimidinas/química , Pirimidinas/farmacologiaRESUMO
We report a series of glutamate and aspartate analogues designed using the hydroxy-1,2,3-triazole moiety as a bioisostere for the distal carboxylic acid. Compound 6b showed unprecedented selectivity among ( S)-2-amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic acid (AMPA) receptor subtypes, confirmed also by an unusual binding mode observed for the crystal structures in complex with the AMPA receptor GluA2 agonist-binding domain. Here, a methionine (Met729) was highly disordered compared to previous agonist-bound structures. This observation provides a possible explanation for the pharmacological profile. In the structure with 7a, an unusual organization of water molecules around the bioisostere arises compared to previous structures of ligands with other bioisosteres. Aspartate analogue 8 with the hydroxy-1,2,3-triazole moiety directly attached to glycine was unexpectedly able to activate both the glutamate and glycine agonist-binding sites of the N-methyl-d-aspartic acid receptor. These observations demonstrate novel features that arise when employing a hydroxytriazole moiety as a bioisostere for the distal carboxylic acid in glutamate receptor agonists.
Assuntos
Agonistas de Aminoácidos Excitatórios/farmacologia , Receptores de AMPA/metabolismo , Triazóis/farmacologia , Animais , Sítios de Ligação , Cristalografia por Raios X , Agonistas de Aminoácidos Excitatórios/síntese química , Agonistas de Aminoácidos Excitatórios/metabolismo , Células HEK293 , Humanos , Ligantes , Ratos , Receptores de AMPA/química , Sinaptossomos/efeitos dos fármacos , Triazóis/síntese química , Triazóis/metabolismoRESUMO
Plasmodium falciparum dihydroorotate dehydrogenase (PfDHODH) has been clinically validated as a target for antimalarial drug discovery, as a triazolopyrimidine class inhibitor (DSM265) is currently undergoing clinical development. Here, we have identified new hydroxyazole scaffold-based PfDHODH inhibitors belonging to two different chemical series. The first series was designed by a scaffold hopping strategy that exploits the use of hydroxylated azoles. Within this series, the hydroxythiadiazole 3 was identified as the best selective PfDHODH inhibitor (IC50 12.0⯵M). The second series was designed by modulating four different positions of the hydroxypyrazole scaffold. In particular, hydroxypyrazoles 7e and 7f were shown to be active in the low µM range (IC50 2.8 and 5.3⯵M, respectively). All three compounds, 3, 7e and 7f showed clear selectivity over human DHODH (IC50â¯>â¯200⯵M), low cytotoxicity, and retained micromolar activity in P. falciparum-infected erythrocytes. The crystallographic structures of PfDHODH in complex with compounds 3 and 7e proved their binding mode, supplying essential data for future optimization of these scaffolds.
Assuntos
Antimaláricos/química , Inibidores Enzimáticos/farmacologia , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/antagonistas & inibidores , Plasmodium falciparum/enzimologia , Antimaláricos/farmacologia , Azóis/química , Azóis/farmacologia , Sítios de Ligação , Cristalografia por Raios X , Di-Hidro-Orotato Desidrogenase , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/metabolismo , Eritrócitos/parasitologia , Humanos , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/metabolismo , Ligação Proteica , Pirazóis/química , Pirazóis/farmacologia , Relação Estrutura-AtividadeRESUMO
BACKGROUND: Human dihydroorotate dehydrogenase (hDHODH, EC 1.3.5.2), a flavindependent mitochondrial enzyme involved in de novo pyrimidine biosynthesis, is a validated therapeutic target for the treatment of autoimmune diseases, such as rheumatoid arthritis and multiple sclerosis. However, human DHODH inhibitors have also been investigated as treatment for cancer, parasite infections (i.e. malaria) and viruses as well as in the agrochemicals industry. OBJECTIVE: An overview of current knowledge of hDHODH inhibitors and their potential uses in diseases where hDHODH is involved. METHOD: This review focuses on recent advances in the development and application of hDHODH inhibitors, specifically covering the patent field, starting from a brief description of enzyme topography and of the strategies usually followed in designing its selective inhibitors. RESULTS: The most important and well-described novelty is the fact that the discovery, in the autumn of 2016, that hDHODH inhibitors are able to induce in vivo myeloid differentiation has led to the possibility of developing novel hDHODH based treatments for Acute Myelogenous Leukemia (AML). CONCLUSION: The review will describe a variety of specific inhibitor classes and conclude on recent and future therapeutic perspectives for this target.
Assuntos
Doenças Autoimunes/tratamento farmacológico , Descoberta de Drogas/tendências , Inibidores Enzimáticos/uso terapêutico , Neoplasias/tratamento farmacológico , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/antagonistas & inibidores , Animais , Doenças Autoimunes/enzimologia , Doenças Autoimunes/imunologia , Di-Hidro-Orotato Desidrogenase , Descoberta de Drogas/métodos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Humanos , Neoplasias/enzimologia , Neoplasias/imunologia , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/imunologia , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/metabolismoRESUMO
NF-κB-inducing kinase (NIK), an oncogenic drug target that is associated with various cancers, is a central signalling component of the non-canonical pathway. A blind screening process, which established that amino pyrazole related scaffolds have an effect on IKKbeta, led to a hit-to-lead optimization process that identified the aminopyrazole 3a as a low µM selective NIK inhibitor. Compound 3a effectively inhibited the NIK-dependent activation of the NF-κB pathway in tumour cells, confirming its selective inhibitory profile.