RESUMO
We describe noncovalent, reversible asparagine ethylenediamine (AsnEDA) inhibitors of the Plasmodium falciparum proteasome (Pf20S) ß5 subunit that spare all active subunits of human constitutive and immuno-proteasomes. The compounds are active against erythrocytic, sexual, and liver-stage parasites, against parasites resistant to current antimalarials, and against P. falciparum strains from patients in Africa. The ß5 inhibitors synergize with a ß2 inhibitor in vitro and in mice and with artemisinin. P. falciparum selected for resistance to an AsnEDA ß5 inhibitor surprisingly harbored a point mutation in the noncatalytic ß6 subunit. The ß6 mutant was resistant to the species-selective Pf20S ß5 inhibitor but remained sensitive to the species-nonselective ß5 inhibitors bortezomib and carfilzomib. Moreover, resistance to the Pf20S ß5 inhibitor was accompanied by increased sensitivity to a Pf20S ß2 inhibitor. Finally, the ß5 inhibitor-resistant mutant had a fitness cost that was exacerbated by irradiation. Thus, used in combination, multistage-active inhibitors of the Pf20S ß5 and ß2 subunits afford synergistic antimalarial activity with a potential to delay the emergence of resistance to artemisinins and each other.
Assuntos
Antimaláricos/química , Plasmodium falciparum/enzimologia , Complexo de Endopeptidases do Proteassoma/química , Inibidores de Proteassoma/química , Proteínas de Protozoários/antagonistas & inibidores , Artemisininas/química , Bortezomib/química , Resistência Microbiana a Medicamentos , Humanos , Lactonas/química , Oligopeptídeos/química , Proteínas de Protozoários/químicaRESUMO
Plasmodium falciparum proteasome (Pf20S) inhibitors are active against Plasmodium at multiple stages-erythrocytic, gametocyte, liver, and gamete activation stages-indicating that selective Pf20S inhibitors possess the potential to be therapeutic, prophylactic, and transmission-blocking antimalarials. Starting from a reported compound, we developed a noncovalent, macrocyclic peptide inhibitor of the malarial proteasome with high species selectivity and improved pharmacokinetic properties. The compound demonstrates specific, time-dependent inhibition of the ß5 subunit of the Pf20S, kills artemisinin-sensitive and artemisinin-resistant P.â falciparum isolates inâ vitro and reduces parasitemia in humanized, P.â falciparum-infected mice.
Assuntos
Antimaláricos/farmacologia , Desenvolvimento de Medicamentos , Malária Falciparum/tratamento farmacológico , Plasmodium falciparum/efeitos dos fármacos , Complexo de Endopeptidases do Proteassoma/metabolismo , Inibidores de Proteassoma/farmacologia , Animais , Antimaláricos/síntese química , Antimaláricos/química , Malária Falciparum/metabolismo , Camundongos , Modelos Moleculares , Conformação Molecular , Testes de Sensibilidade Parasitária , Plasmodium falciparum/enzimologia , Inibidores de Proteassoma/síntese química , Inibidores de Proteassoma/químicaRESUMO
Accumulating evidence suggests that fibrinogen, a key protein in the coagulation cascade, plays an important role in circulatory dysfunction in Alzheimer's disease (AD). Previous work has shown that the interaction between fibrinogen and ß-amyloid (Aß), a hallmark pathological protein in AD, induces plasmin-resistant abnormal blood clots, delays fibrinolysis, increases inflammation, and aggravates cognitive function in mouse models of AD. Since Aß oligomers have a much stronger affinity for fibrinogen than Aß monomers, we tested whether amyloid aggregation inhibitors could block the Aß-fibrinogen interaction and found that some Aß aggregation inhibitors showed moderate inhibitory efficacy against this interaction. We then modified a hit compound so that it not only showed a strong inhibitory efficacy toward the Aß-fibrinogen interaction but also retained its potency toward the Aß42 aggregation inhibition process. Furthermore, our best hit compound, TDI-2760, modulated Aß42-induced contact system activation, a pathological condition observed in some AD patients, in addition to inhibiting the Aß-fibrinogen interaction and Aß aggregation. Thus, TDI-2760 has the potential to lessen vascular abnormalities as well as Aß aggregation-driven pathology in AD.
Assuntos
Peptídeos beta-Amiloides/metabolismo , Fibrinogênio/metabolismo , Fragmentos de Peptídeos/metabolismo , Agregados Proteicos/efeitos dos fármacos , Mapas de Interação de Proteínas/efeitos dos fármacos , Pirimidinas/química , Pirimidinas/farmacologia , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Desenho de Fármacos , Humanos , Agregação Patológica de Proteínas/tratamento farmacológico , Agregação Patológica de Proteínas/metabolismoRESUMO
The majority of patients with Alzheimer disease (AD) suffer from impaired cerebral circulation. Accumulating evidence suggests that fibrinogen, the main protein component of blood clots, plays an important role in this circulatory dysfunction in AD. Fibrinogen interacts with ß-amyloid (Aß), forming plasmin-resistant abnormal blood clots, and increased fibrin deposition is found in the brains of AD patients and mouse models. In this study, we investigated the biochemical and structural details of the Aß-fibrinogen interaction. We identified the central region of Aß42 as the most critical region for the interaction, which can be inhibited by specific antibodies against the central region of Aß and by naturally occurring p3 peptides, Aß17-40 and Aß17-42. X-ray crystallographic analysis revealed that Aß42 binding to fragment D of fibrinogen induced a structural change in the C-terminal region of the fibrinogen ß-chain (ß384-393). Furthermore, we identified an additional Aß-binding site within the αC region of fibrinogen. Aß binding to this αC region blocked plasmin-mediated fibrin cleavage at this site, resulting in the generation of increased levels of a plasmin-resistant fibrin degradation fragment. Overall, our study elucidates the Aß-fibrinogen interaction and clarifies the mechanism by which Aß-fibrinogen binding delays fibrinolysis by plasmin. These results may facilitate the development of effective therapeutics against the Aß-fibrinogen interaction to treat cerebrovascular abnormalities in AD.
Assuntos
Peptídeos beta-Amiloides/química , Peptídeos beta-Amiloides/metabolismo , Fibrinogênio/química , Fibrinogênio/metabolismo , Sequência de Aminoácidos , Animais , Anticorpos/metabolismo , Produtos de Degradação da Fibrina e do Fibrinogênio/química , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Fibrinolisina/metabolismo , Fibrinólise , Humanos , Camundongos , Ligação Proteica , Dodecilsulfato de Sódio/metabolismoRESUMO
Age-associated alterations in the mucosal immune system are generally termed mucosal immunosenescence. The major change seen in the aged mucosa is a failure to elicit an antigen-specific secretory IgA (SIgA) antibody response, which is a central player for host defense from various pathogens at mucosal surfaces. In this regard, it would be a first priority to compensate for mucosal dysregulation in the elderly in order to maintain their health in aging. We have successfully established antigen-specific SIgA antibody responses in aged (2 years old) mice, which provide protective immunity from Streptococcus pneumoniae and influenza virus infections, by using a new adjuvant system consisting of a plasmid encoding Flt3 ligand (pFL) and CpG ODN. In order to explore possible use of current mucosal vaccine strategies for the elderly, we have adoptively transferred adipose tissue-derived mesenchymal stem cells (AMSCs) to aged mice prior to mucosal vaccination. This immune therapy successfully resulted in protective antigen-specific antibody responses in the intestinal mucosa of aged mice that were comparable to those seen in young adult mice. In this regard, we postulate that adoptively transferred AMSCs could augment dendritic cell functions in aged mice. The potential cellular and molecular mechanisms whereby AMSCs restore mucosal immunity in immunosenescence are discussed in this short review. A stem cell transfer system could be an attractive and effective immunologic intervention strategy to reverse mucosal immunosenescence.
Assuntos
Tecido Adiposo/imunologia , Envelhecimento/imunologia , Imunidade nas Mucosas/imunologia , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/imunologia , Infecções Pneumocócicas/terapia , Streptococcus pneumoniae/imunologia , Envelhecimento/patologia , Animais , Humanos , Camundongos , Infecções Pneumocócicas/imunologia , Infecções Pneumocócicas/patologiaRESUMO
CCR6 has been implicated in both autoimmune diseases and non-autoimmune diseases. Thus, inhibition of CCR6-dependent cell migration is an attractive strategy for their treatment. An orally available small molecule inhibitor of CCR6 could therefore be a useful biological probe for the pathophysiological studies. Initial SAR study of a hit compound provided potent N-benzenesulfonylpiperidine derivatives that suppressed CCL20-induced Gi signals. By subsequent scaffold morphing of the central ring and further optimization, we identified a novel series of 1,4-trans-1-benzenesulfonyl-4-aminocyclohexanes as potent and selective CCR6 inhibitors with good pharmacokinetic properties. Our compounds showed good correlation between Gi signal inhibitory activity and cell migration inhibitory activity in human CCR6-transfected CHO cells. In addition, representative compound 35 potently inhibited CCR6-dependent cell migration and the increase in ERK phosphorylation in human primary cells. Therefore, the compound could be used effectively as a biological probe against human CCR6.
Assuntos
Aminas/farmacologia , Cicloexanos/farmacologia , Piperidinas/farmacologia , Receptores CCR6/antagonistas & inibidores , Bibliotecas de Moléculas Pequenas/farmacologia , Aminas/síntese química , Aminas/química , Animais , Linfócitos B/efeitos dos fármacos , Células CHO , Movimento Celular/efeitos dos fármacos , Cricetulus , Cicloexanos/síntese química , Cicloexanos/química , Relação Dose-Resposta a Droga , Haplorrinos , Humanos , Estrutura Molecular , Piperidinas/síntese química , Piperidinas/química , Receptores CCR6/metabolismo , Bibliotecas de Moléculas Pequenas/síntese química , Bibliotecas de Moléculas Pequenas/química , Relação Estrutura-AtividadeRESUMO
G-protein-coupled receptor 52 (GPR52) is classified as an orphan Gs-coupled G-protein-coupled receptor. GPR52 cancels dopamine D2 receptor signaling and activates dopamine D1/N-methyl-d-aspartate receptors via intracellular cAMP accumulation. Therefore, GPR52 agonists are expected to alleviate symptoms of psychotic disorders. A novel series of 1-(benzothiophen-7-yl)-1H-pyrazole as GPR52 agonists was designed and synthesized based on compound 1b. Compound 1b has been reported by our group as the first orally active GPR52 agonist, but high lipophilicity and poor aqueous solubility still remained as issues for candidate selection. To resolve these issues, replacement of the benzene ring at the 7-positon of compound 1b with heterocylic rings, such as pyrazole and pyridine, was greatly expected to reduce lipophilicity to levels for which calculated logD values were lower than that of compound 1b. While evaluating the pyrazole derivatives, introduction of a methyl substituent at the 3-position of the pyrazole ring led to increased GPR52 agonistic activity. Moreover, additional methyl substituent at the 5-position of the pyrazole and further introduction of hydroxy group to lower logD led to significant improvement of solubility while maintaining the activity. As a result, we identified 3-methyl-5-hydroxymethyl-1H-pyrazole derivative 17 (GPR52 EC50â¯=â¯21â¯nM, Emaxâ¯=â¯103%, logDâ¯=â¯2.21, Solubility at pH 6.8â¯=â¯21⯵g/mL) with potent GPR52 agonistic activity and good solubility compared to compound 1b. Furthermore, this compound 17 dose-dependently suppressed methamphetamine-induced hyperlocomotion in mice.
Assuntos
Pirazóis/farmacologia , Receptores Acoplados a Proteínas G/agonistas , Tiofenos/farmacologia , Animais , Relação Dose-Resposta a Droga , Desenho de Fármacos , Humanos , Locomoção/efeitos dos fármacos , Masculino , Metanfetamina , Camundongos , Camundongos Endogâmicos ICR , Estrutura Molecular , Pirazóis/síntese química , Pirazóis/química , Relação Estrutura-Atividade , Tiofenos/síntese química , Tiofenos/químicaRESUMO
A new class of corticotropin releasing factor 1 (CRF1) receptor antagonists characterized by a tricyclic core ring was designed and synthesized. Novel tricyclic derivatives 2a-e were designed as CRF1 receptor antagonists based on conformation analysis of our original 2-anilinobenzimidazole CRF1 receptor antagonist. The synthesized tricyclic derivatives 2a-e showed CRF1 receptor binding activity with IC50 values of less than 400â¯nM, and the 1,2,3,4-tetrahydropyrimido-[1,2-a]benzimidazole derivative 2e was selected as a lead compound with potent in vitro CRF1 receptor binding activity (IC50â¯=â¯7.1â¯nM). To optimize the pharmacokinetic profiles of lead compound 2e, we explored suitable substituents on the 1-position and 6-position, leading to the identification of compound 42c-R, which exhibited potent CRF1 receptor binding activity (IC50â¯=â¯58â¯nM) with good oral bioavailability (Fâ¯=â¯68% in rats). Compound 42c-R exhibited dose-dependent inhibition of [125I]-CRF binding in the frontal cortex (5 and 10â¯mg/kg, p.o.) as well as suppression of locomotor activation induced by intracerebroventricular administration of CRF in rats (10â¯mg/kg, p.o.). These results suggest that compound 42c-R successfully binds CRF1 receptors in the brain and exhibits the potential to be further examined for clinical studies.
Assuntos
Benzimidazóis/farmacologia , Pirimidinas/farmacologia , Receptores de Hormônio Liberador da Corticotropina/antagonistas & inibidores , Animais , Benzimidazóis/administração & dosagem , Benzimidazóis/síntese química , Benzimidazóis/química , Encéfalo/metabolismo , Células CHO , Cricetulus , Ciclização , Desenho de Fármacos , Humanos , Masculino , Microssomos Hepáticos/metabolismo , Conformação Molecular , Simulação de Acoplamento Molecular , Pirimidinas/administração & dosagem , Pirimidinas/síntese química , Pirimidinas/química , Ratos Wistar , Receptores de Hormônio Liberador da Corticotropina/química , EstereoisomerismoRESUMO
G protein-coupled receptor 52 (GPR52) agonists are expected to improve the symptoms of psychiatric disorders. During exploration for a novel class of GPR52 agonists with good pharmacokinetic profiles, we synthesized 4-(3-(3-fluoro-5-(trifluoromethyl)benzyl)-5-methyl-1H-1,2,4-triazol-1-yl)-2-methylbenzamide (4u; half maximal effective concentration (EC50)=75nM, maximal response (Emax)=122%) starting from a high-throughput screening hit 3 (EC50=470nM, Emax=56%). The structural features of a reported GPR52 agonist were applied to 3, led to design 4-azolylbenzamides as novel GPR52 agonists. A structure-activity relationship study of 4-azolylbenzamide resulted in the design of the 1,2,4-triazole derivative 4u, which demonstrated excellent bioavailability in rats (F=53.8%). Oral administration of 4u (10mg/kg) significantly suppressed methamphetamine-induced hyperlocomotion in mice. Thus, 4u is a promising lead compound for drug discovery research of GPR52 agonists.
Assuntos
Benzamidas/química , Benzamidas/farmacologia , Receptores Acoplados a Proteínas G/agonistas , Triazóis/química , Triazóis/farmacologia , Administração Oral , Animais , Benzamidas/administração & dosagem , Benzamidas/farmacocinética , Barreira Hematoencefálica/metabolismo , Desenho de Fármacos , Humanos , Locomoção/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos ICR , Modelos Moleculares , Receptores Acoplados a Proteínas G/metabolismo , Relação Estrutura-Atividade , Triazóis/administração & dosagem , Triazóis/farmacocinéticaRESUMO
Compound 1 exhibits potent binding inhibition activity against a corticotropin-releasing factor 1 (CRF1) receptor (IC50=9.5nM) and in vitro antagonistic activity (IC50=88nM) but is rapidly metabolized by human hepatic microsomes (182µL/min/mg). Here we identified metabolically stable compounds with potent CRF binding inhibitory activity. Structure-activity relationship (SAR) studies considering in vitro metabolic stability revealed that 4-chloro-2-(2,4-dichloro-6-methylphenoxy)-1-methyl-7-(pentan-3-yl)-1H-benzimidazole 24d was more stable in human microsomes (87µL/min/mg) than compound 1. Compound 24d demonstrated potent CRF binding inhibitory activity (IC50=4.1nM), in vitro antagonistic activity (IC50=44nM), and slow dissociation from the CRF1 receptor. Orally administered compound 24d (6-24µmol/kg) showed ex vivo CRF1 receptor binding in the rat pituitary, olfactory bulb, and frontal cortex and suppressed stress-induced adrenocorticotropic hormone (ACTH) secretion. In this report, we discuss SAR studies on the metabolic stability as well as CRF binding inhibitory activity of the benzimidazole series as CRF1 receptor antagonists and the pharmacological profiles of compound 24d.
Assuntos
Benzimidazóis/farmacologia , Receptores de Hormônio Liberador da Corticotropina/antagonistas & inibidores , Administração Oral , Animais , Células CHO , Cricetulus , Humanos , Masculino , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/metabolismo , Ratos , Ratos Wistar , Ovinos , Relação Estrutura-AtividadeRESUMO
A promising lead compound 1 of a benzimidazole series has been identified as a corticotropin-releasing factor 1 (CRF1) receptor antagonist. In this study, we focused on replacement of a 7-alkylamino group of 1, predicted to occupy a large lipophilic pocket of a CRF1 receptor, with an aryl group. During the course of this examination, we established new synthetic approaches to 2,7-diarylaminobenzimidazoles. The novel synthesis of 7-arylaminobenzimidazoles culminated in the identification of compounds exhibiting inhibitory activities comparable to the alkyl analog 1. A representative compound, p-methoxyanilino analog 16g, showed potent CRF binding inhibitory activity against a human CRF1 receptor and human CRF1 receptor antagonistic activity (IC50=27nM, 56nM, respectively). This compound exhibited ex vivo (125)I-Tyr(0) ((125)I-CRF) binding inhibitory activity in mouse frontal cortex, olfactory bulb, and pituitary gland at 20mg/kg after oral administration. In this report, we discuss the structure-activity-relationship of these 7-arylamino-1H-benzimidazoles and their synthetic method.
Assuntos
Benzimidazóis/química , Benzimidazóis/farmacologia , Receptores de Hormônio Liberador da Corticotropina/antagonistas & inibidores , Aminação , Animais , Descoberta de Drogas , Humanos , Camundongos , Modelos Moleculares , Receptores de Hormônio Liberador da Corticotropina/metabolismoRESUMO
With increasing reports of resistance to artemisinins and artemisinin-combination therapies, targeting the Plasmodium proteasome is a promising strategy for antimalarial development. We recently reported a highly selective Plasmodium falciparum proteasome inhibitor with anti-malarial activity in the humanized mouse model. To balance the permeability of the series of macrocycles with other drug-like properties, we conducted further structure-activity relationship studies on a biphenyl ether-tethered macrocyclic scaffold. Extensive SAR studies around the P1, P3, and P5 groups and peptide backbone identified compound TDI-8414. TDI-8414 showed nanomolar antiparasitic activity, no toxicity to HepG2 cells, high selectivity against the Plasmodium proteasome over the human constitutive proteasome and immunoproteasome, improved solubility and PAMPA permeability, and enhanced metabolic stability in microsomes and plasma of both humans and mice.
Assuntos
Antimaláricos , Plasmodium , Humanos , Animais , Camundongos , Antimaláricos/farmacologia , Antimaláricos/química , Complexo de Endopeptidases do Proteassoma/metabolismo , Relação Estrutura-Atividade , Plasmodium falciparum/metabolismo , Inibidores de Proteassoma/farmacologia , Inibidores de Proteassoma/químicaRESUMO
Aberrant gene-silencing through dysregulation of polycomb protein activity has emerged as an important oncogenic mechanism in cancer, implicating polycomb proteins as important therapeutic targets. Recently, an inhibitor targeting EZH2, the methyltransferase component of PRC2, received U.S. Food and Drug Administration approval following promising clinical responses in cancer patients. However, the current array of EZH2 inhibitors have poor brain penetrance, limiting their use in patients with central nervous system malignancies, a number of which have been shown to be sensitive to EZH2 inhibition. To address this need, we have identified a chemical strategy, based on computational modeling of pyridone-containing EZH2 inhibitor scaffolds, to minimize P-glycoprotein activity, and here we report the first brain-penetrant EZH2 inhibitor, TDI-6118 (compound 5). Additionally, in the course of our attempts to optimize this compound, we discovered TDI-11904 (compound 21), a novel, highly potent, and peripherally active EZH2 inhibitor based on a 7 member ring structure.
RESUMO
With over 200 million cases and close to half a million deaths each year, malaria is a threat to global health, particularly in developing countries. Plasmodium falciparum, the parasite that causes the most severe form of the disease, has developed resistance to all antimalarial drugs. Resistance to the first-line antimalarial artemisinin and to artemisinin combination therapies is widespread in Southeast Asia and is emerging in sub-Saharan Africa. The P. falciparum proteasome is an attractive antimalarial target because its inhibition kills the parasite at multiple stages of its life cycle and restores artemisinin sensitivity in parasites that have become resistant through mutation in Kelch K13. Here, we detail our efforts to develop noncovalent, macrocyclic peptide malaria proteasome inhibitors, guided by structural analysis and pharmacokinetic properties, leading to a potent, species-selective, metabolically stable inhibitor.
Assuntos
Antimaláricos , Artemisininas , Malária Falciparum , Antimaláricos/farmacologia , Antimaláricos/uso terapêutico , Artemisininas/farmacologia , Resistência a Medicamentos , Humanos , Malária Falciparum/tratamento farmacológico , Peptídeos/uso terapêutico , Plasmodium falciparum , Inibidores de Proteassoma/farmacologia , Inibidores de Proteassoma/uso terapêutico , Proteínas de Protozoários/genéticaRESUMO
Phenylketonuria (PKU) is a heterogeneous metabolic disorder caused by a deficiency in hepatic phenylalanine hydroxylase (PAH). On the basis of phenotype/genotype correlations, determination of phenylketonuric genotype is important for classification of the clinical phenotype and treatment of PKU, including tetrahydrobiopterin therapy. We characterized the genotypes of 203 Japanese patients with PKU and hyperphenylalaninemia using the following systems: (1) denaturing high-performance liquid chromatography with a GC-clamped primer; (2) direct sequencing; and, (3) multiplex ligation-dependent probe amplification. Of 406 mutant alleles, 390 (96%) were genotyped; 65 mutations were identified, including 22 new mutations. R413P, R241C, IVS4-1g>a, R111X and R243Q were prevalent mutations. Mutations prevalent in the Japanese cohort are also common in Korean and Northern Chinese populations, suggesting same origin. The spectrum of prevalent mutations was not significantly different among six Japanese districts, indicating that Japan comprises a relatively homogeneous ethnic group. We classified the mutations by clinical phenotypes and in vivo PAH activity and estimated the mutations with potential tetrahydrobiopterin (BH(4)) responsiveness. The frequency of BH(4) responsiveness based on the genotype was 29.1% in Japanese PKU patients. A catalog of PKU genotypes would be useful for predicting clinical phenotype, deciding on the subsequent treatment of PKU including BH(4) therapy, and genetic counseling in East Asia.
Assuntos
Biopterinas/análogos & derivados , Fenótipo , Fenilalanina Hidroxilase/genética , Fenilcetonúrias/genética , Sequência de Bases , Biopterinas/uso terapêutico , Cromatografia Líquida de Alta Pressão , Primers do DNA/genética , Genótipo , Humanos , Japão , Dados de Sequência Molecular , Mutação de Sentido Incorreto/genética , Técnicas de Amplificação de Ácido Nucleico , Fenilalanina/sangue , Fenilcetonúrias/tratamento farmacológico , Fenilcetonúrias/patologia , Análise de Sequência de DNARESUMO
A new class of pyrrolo[2,3-d]pyrimidin-4-one corticotropin-releasing factor 1 (CRF(1)) receptor antagonists has been designed and synthesized. In general, reported CRF(1) receptor antagonists possess a sp(2)-nitrogen atom as hydrogen bonding acceptor (HBA) on their core scaffolds. We proposed to use a carbonyl group of pyrrolo[2,3-d]pyrimidin-4-one derivatives as a replacement for the sp(2)-nitrogen atom as HBA in classical CRF(1) receptor antagonists. As a result, several pyrrolo[2,3-d]pyrimidin-4-one derivatives showed CRF(1) receptor binding affinity with IC(50) values in the submicromolar range. Ex vivo (125)I-sauvagine binding studies showed that 2-(dipropylamino)-3,7-dimethyl-5-(2,4,6-trimethylphenyl)-3,7-dihydro-4H-pyrrolo[2,3-d]pyrimidin-4-one (16b) (30 mg/kg, p.o.) was able to penetrate into the brain and inhibit radioligand binding to CRF(1) receptors (frontal cortex, olfactory bulb, and pituitary) in mice. We identified pyrrolo[2,3-d]pyrimidin-4-one derivatives as the first CRF(1) antagonists with a carbonyl-based HBA.
Assuntos
Pirimidinas/química , Pirróis/química , Receptores de Hormônio Liberador da Corticotropina/antagonistas & inibidores , Animais , Encéfalo/metabolismo , Avaliação Pré-Clínica de Medicamentos , Ligação de Hidrogênio , Cetonas/química , Camundongos , Pirimidinas/síntese química , Pirimidinas/farmacologia , Pirróis/síntese química , Pirróis/farmacologia , Receptores de Hormônio Liberador da Corticotropina/metabolismoRESUMO
Melanin-concentrating hormone receptor 1 (MCHR1) antagonists have been studied as potential agents for the treatment of obesity. Initial structure-activity relationship studies of in-house hit compound 1a and subsequent optimization studies resulted in the identification of tetrahydroisoquinoline derivative 23, 1-(2-acetyl-1,2,3,4-tetrahydroisoquinolin-7-yl)-4-[4-(4-chlorophenyl)piperidin-1-yl]butan-1-one, as a potent hMCHR1 antagonist. A homology model of hMCHR1 suggests that these compounds interact with Asn 294 and Asp 123 in the binding site of hMCHR1 to enhance binding affinity. Oral administration of compound 23 dose-dependently reduced food intake in diet-induced obesity (DIO)-F344 rats.
Assuntos
Fármacos Antiobesidade/química , Fármacos Antiobesidade/farmacologia , Benzazepinas/química , Benzazepinas/farmacologia , Obesidade/tratamento farmacológico , Receptores do Hormônio Hipofisário/antagonistas & inibidores , Animais , Fármacos Antiobesidade/síntese química , Fármacos Antiobesidade/farmacocinética , Benzazepinas/síntese química , Benzazepinas/farmacocinética , Células CHO , Cricetinae , Humanos , Concentração Inibidora 50 , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Simulação de Dinâmica Molecular , Obesidade/metabolismo , Ligação Proteica , Ratos , Ratos Endogâmicos F344 , Espectrometria de Massas por Ionização por Electrospray , Relação Estrutura-AtividadeRESUMO
INTRODUCTION: Congenital hyperinsulinism and hyperammonemia (CHH) is caused by gain of function of glutamate dehydrogenase (GDH). The genetic abnormalities are known to be located in three specific regions on the GDH protein. We describe here three different missense mutations identified in five new Japanese patients with CHH. And to study the genotype-phenotype correlations in patients with GLUD1 mutations, we analyzed previously reported Japanese cases. METHODS: An Epstein-Barr virus-transformed lymphoblastoid cell line was established from the 5 patients and control subjects, and was used for enzymatic and molecular analyses. RESULTS: All patients developed seizures with loss of consciousness associated with hypoglycemia and had persistent hyperammonemia. All patients had similar basal GDH activity of lymphoblasts and insensitivity to GTP inhibition. Genetic studies identified heterozygous I444M mutation in Patient 11, S217C mutation in Patient 1, and H262Y mutation in Patients 2, 3, and 4. Patients 3 and 4 were child and father, respectively. COS cell expression study confirmed that I444M and H262Y mutations were disease-causing genes. CONCLUSIONS: We identified three mutations (I444M, H262Y, and S217C), and the former is a newly described mutation. A summary of 17 reported Japanese patients (10 boys and 7 girls) with GDH mutations showed 8 patients had mutation at the site of the GTP-binding region, 2 at the site of the antenna-like structure, and 7 at the site of the hinge region. Analysis of the reported cases showed no clear association between clinical phenotype and mutation sites. However, G446D mutation seems to be associated with serious abnormalities.
Assuntos
Glutamato Desidrogenase/genética , Hiperinsulinismo/genética , Hipoglicemia/genética , Mutação de Sentido Incorreto , Adolescente , Animais , Células COS , Linhagem Celular Transformada , Criança , Pré-Escolar , Chlorocebus aethiops , Análise Mutacional de DNA , Feminino , Predisposição Genética para Doença , Glutamato Desidrogenase/metabolismo , Humanos , Hiperinsulinismo/complicações , Hiperinsulinismo/enzimologia , Hipoglicemia/complicações , Hipoglicemia/enzimologia , Lactente , Recém-Nascido , Japão , Masculino , Fenótipo , Convulsões/enzimologia , Convulsões/genética , Transfecção , Inconsciência/enzimologia , Inconsciência/genéticaRESUMO
Tuberculosis remains a leading cause of death from a single bacterial infection worldwide. Efforts to develop new treatment options call for expansion into an unexplored target space to expand the drug pipeline and bypass resistance to current antibiotics. Lipoamide dehydrogenase is a metabolic and antioxidant enzyme critical for mycobacterial growth and survival in mice. Sulfonamide analogs were previously identified as potent and selective inhibitors of mycobacterial lipoamide dehydrogenase in vitro but lacked activity against whole mycobacteria. Here we present the development of analogs with improved permeability, potency, and selectivity, which inhibit the growth of Mycobacterium tuberculosis in axenic culture on carbohydrates and within mouse primary macrophages. They increase intrabacterial pyruvate levels, supporting their on-target activity within mycobacteria. Distinct modalities of binding between the mycobacterial and human enzymes contribute to improved potency and hence selectivity through induced-fit tight binding interactions within the mycobacterial but not human enzyme, as indicated by kinetic analysis and crystallography.
Assuntos
Mycobacterium tuberculosis , Tuberculose , Animais , Antibacterianos/uso terapêutico , Di-Hidrolipoamida Desidrogenase/metabolismo , Humanos , Cinética , Camundongos , Mycobacterium tuberculosis/metabolismo , Tuberculose/tratamento farmacológicoRESUMO
Treatment of tuberculosis (TB) currently takes at least 6 months. Latent Mycobacterium tuberculosis (Mtb) is phenotypically tolerant to most anti-TB drugs. A key hypothesis is that drugs that kill nonreplicating (NR) Mtb may shorten treatment when used in combination with conventional drugs. The Mtb proteasome (Mtb20S) could be such a target because its pharmacological inhibition kills NR Mtb and its genetic deletion renders Mtb unable to persist in mice. Here, we report a series of macrocyclic peptides that potently and selectively target the Mtb20S over human proteasomes, including macrocycle 6. The cocrystal structure of macrocycle 6 with Mtb20S revealed structural bases for the species selectivity. Inhibition of 20S within Mtb by 6 dose dependently led to the accumulation of Pup-tagged GFP that is degradable but resistant to depupylation and death of nonreplicating Mtb under nitrosative stress. These results suggest that compounds of this class have the potential to develop as anti-TB therapeutics.