RESUMO
The search for novel effective TAAR1 ligands continues to draw great attention due to the wide range of pharmacological applications related to TAAR1 targeting. Herein, molecular docking studies of known TAAR1 ligands, characterized by an oxazoline core, have been performed in order to identify novel promising chemo-types for the discovery of more active TAAR1 agonists. In particular, the oxazoline-based compound S18616 has been taken as a reference compound for the computational study, leading to the development of quite flat and conformationally locked ligands. The choice of a "Y-shape" conformation was suggested for the design of TAAR1 ligands, interacting with the protein cavity delimited by ASP103 and aromatic residues such as PHE186, PHE195, PHE268, and PHE267. The obtained results allowed us to preliminary in silico screen an in-house series of pyrimidinone-benzimidazoles (1a-10a) as a novel scaffold to target TAAR1. Combined ligand-based (LBCM) and structure based (SBCM) computational methods suggested the biological evaluation of compounds 1a-10a, leading to the identification of derivatives 1a-3a (hTAAR1 EC50 = 526.3-657.4 nM) as promising novel TAAR1 agonists.
Assuntos
Simulação de Acoplamento Molecular , Receptores Acoplados a Proteínas G , Receptores Acoplados a Proteínas G/agonistas , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/química , Humanos , Ligantes , Relação Estrutura-Atividade , Modelos Moleculares , Ligação Proteica , Sítios de Ligação , Oxazóis/química , Oxazóis/farmacologia , Benzimidazóis/química , Benzimidazóis/farmacologia , Estrutura Molecular , Descoberta de DrogasRESUMO
A library of eighteen thienocycloalkylpyridazinones was synthesized for human acetylcholinesterase (hAChE) and butyrylcholinesterase (hBChE) inhibition and serotonin 5-HT6 receptor subtype interaction by following a multitarget-directed ligand approach (MTDL), as a suitable strategy for treatment of Alzheimer's disease (AD). The novel compounds featured a tricyclic scaffold, namely thieno[3,2-h]cinnolinone, thienocyclopentapyridazinone and thienocycloheptapyridazinone, connected through alkyl chains of variable length to proper amine moieties, most often represented by N-benzylpiperazine or 1-(phenylsulfonyl)-4-(piperazin-1-ylmethyl)-1H-indole as structural elements addressing AChE and 5-HT6 interaction, respectively. Our study highlighted the versatility of thienocycloalkylpyridazinones as useful architectures for AChE interaction, with several N-benzylpiperazine-based analogues emerging as potent and selective hAChE inhibitors with IC50 in the 0.17-1.23 µM range, exhibiting low to poor activity for hBChE (IC50 = 4.13-9.70 µM). The introduction of 5-HT6 structural moiety phenylsulfonylindole in place of N-benzylpiperazine, in tandem with a pentamethylene linker, gave potent 5-HT6 thieno[3,2-h]cinnolinone and thienocyclopentapyridazinone-based ligands both displaying hAChE inhibition in the low micromolar range and unappreciable activity towards hBChE. While docking studies provided a rational structural explanation for AChE/BChE enzyme and 5-HT6 receptor interaction, in silico prediction of ADME properties of tested compounds suggested further optimization for development of such compounds in the field of MTDL for AD.
Assuntos
Acetilcolinesterase , Doença de Alzheimer , Humanos , Acetilcolinesterase/metabolismo , Butirilcolinesterase/metabolismo , Serotonina , Inibidores da Colinesterase/farmacologia , Inibidores da Colinesterase/química , Ligantes , Relação Estrutura-Atividade , Simulação de Acoplamento MolecularRESUMO
BACKGROUND AND AIMS: POLR3B gene encodes a subunit of RNA polymerase III (Pol III). Biallelic mutations in POLR3B are associated with leukodystrophies, but recently de novo heterozygous mutations have been described in early onset peripheral demyelinating neuropathies with or without central involvement. Here, we report the first Italian case carrying a de novo variant in POLR3B with a pure neuropathy phenotype and primary axonal involvement of the largest nerve fibers. METHODS: Nerve conduction studies, sympathetic skin response, dynamic sweat test, tactile and thermal quantitative sensory testing and brain magnetic resonance imaging were performed according to standard procedures. Histopathological examination was performed on skin and sural nerve biopsies. Molecular analysis of the proband and his relatives was performed with Next Generation Sequencing. The impact of the identified variant on the overall protein structure was evaluated through rotamers method. RESULTS: Since his early adolescence, the patient presented with signs of polyneuropathy with severe distal weakness, atrophy, and reduced sensation. Neurophysiological studies showed a sensory-motor axonal polyneuropathy, with confirmed small fiber involvement. In addition, skin biopsy and sural nerve biopsy showed predominant large fibers involvement. A trio's whole exome sequencing revealed a novel de novo variant p.(Arg1046Cys) in POLR3B, which was classified as Probably Pathogenic. Molecular modeling data confirmed a deleterious effect of the variant on protein structure. INTERPRETATION: Neurophysiological and morphological findings suggest a primary axonal involvement of the largest nerve fibers in POLR3B-related neuropathies. A partial loss of function mechanism is proposed for both neuropathy and leukodystrophy phenotypes.
Assuntos
Doenças Desmielinizantes , Doenças do Sistema Nervoso Periférico , Polineuropatias , RNA Polimerase III , Adolescente , Humanos , Axônios , Doenças Desmielinizantes/genética , Mutação , Fibras Nervosas/metabolismo , Doenças do Sistema Nervoso Periférico/genética , Polineuropatias/genética , Proteínas/genética , RNA Polimerase III/genética , RNA Polimerase III/metabolismoRESUMO
Sirtuin isoform 2 (SIRT2) is one of the seven sirtuin isoforms present in humans, being classified as class III histone deacetylases (HDACs). Based on the high sequence similarity among SIRTs, the identification of isoform selective modulators represents a challenging task, especially for the high conservation observed in the catalytic site. Efforts in rationalizing selectivity based on key residues belonging to the SIRT2 enzyme were accompanied in 2015 by the publication of the first X-ray crystallographic structure of the potent and selective SIRT2 inhibitor SirReal2. The subsequent studies led to different experimental data regarding this protein in complex with further different chemo-types as SIRT2 inhibitors. Herein, we reported preliminary Structure-Based Virtual Screening (SBVS) studies using a commercially available library of compounds to identify novel scaffolds for the design of new SIRT2 inhibitors. Biochemical assays involving five selected compounds allowed us to highlight the most effective chemical features supporting the observed SIRT2 inhibitory ability. This information guided the following in silico evaluation and in vitro testing of further compounds from in-house libraries of pyrazolo-pyrimidine derivatives towards novel SIRT2 inhibitors (1-5). The final results indicated the effectiveness of this scaffold for the design of promising and selective SIRT2 inhibitors, featuring the highest inhibition among the tested compounds, and validating the applied strategy.
Assuntos
Sirtuína 2 , Sirtuína 2/antagonistas & inibidores , Sirtuína 2/química , Domínio Catalítico , Bibliotecas de Moléculas Pequenas , Conformação Proteica , Simulação de Acoplamento MolecularRESUMO
Cystic fibrosis is a hereditary disease mainly caused by the deletion of the Phe 508 (F508del) of the cystic fibrosis transmembrane conductance regulator (CFTR) protein that is thus withheld in the endoplasmic reticulum and rapidly degraded by the ubiquitin/proteasome system. Cystic fibrosis remains a potentially fatal disease, but it has become treatable as a chronic condition due to some CFTR-rescuing drugs that, when used in combination, increase in their therapeutic effect due to a synergic action. Also, dietary supplementation of natural compounds in combination with approved drugs could represent a promising strategy to further alleviate cystic fibrosis symptoms. On these bases, we screened by in silico drug repositioning 846 small synthetic or natural compounds from the AIFA database to evaluate their capacity to interact with the highly druggable lumacaftor binding site of F508del-CFTR. Among the identified hits, nicotinamide (NAM) was predicted to accommodate into the lumacaftor binding region of F508del-CFTR without competing against the drug but rather stabilizing its binding. The effective capacity of NAM to bind F508del-CFTR in a lumacaftor-uncompetitive manner was then validated experimentally by surface plasmon resonance analysis. Finally, the capacity of NAM to synergize with lumacaftor increasing its CFTR-rescuing activity was demonstrated in cell-based assays. This study suggests the possible identification of natural small molecules devoid of side effects and endowed with the capacity to synergize with drugs currently employed for the treatment of cystic fibrosis, which hopefully will increase the therapeutic efficacy with lower doses.
Assuntos
Regulador de Condutância Transmembrana em Fibrose Cística , Fibrose Cística , Humanos , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Fibrose Cística/tratamento farmacológico , Fibrose Cística/genética , Fibrose Cística/metabolismo , Reposicionamento de Medicamentos , Complexo de Endopeptidases do Proteassoma/metabolismo , Benzodioxóis/farmacologia , Benzodioxóis/uso terapêutico , Aminopiridinas/farmacologia , Aminopiridinas/uso terapêutico , Niacinamida/uso terapêutico , Ubiquitinas/metabolismo , MutaçãoRESUMO
Tomato brown rugose fruit virus (ToBRFV) is a new damaging plant virus of great interest from both an economical and research point of view. ToBRFV is transmitted by contact, remains infective for months, and to-date, no resistant cultivars have been developed. Due to the relevance of this virus, new effective, sustainable, and operator-safe antiviral agents are needed. Thus, 4-hydroxybenzoic acid was identified as the main product of the alkaline autoxidation at high temperature of the methanolic extract of the leaves of C. micranthum, known for antiviral activity. The autoxidized extract and 4-hydroxybenzoic acid were assayed in in vitro experiments, in combination with a mechanical inoculation test of tomato plants. Catechinic acid, a common product of rearrangement of catechins in hot alkaline solution, was also tested. Degradation of the viral particles, evidenced by the absence of detectable ToBRFV RNA and the loss of virus infectivity, as a possible consequence of disassembly of the virus coat protein (CP), were shown. Homology modeling was then applied to prepare the protein model of ToBRFV CP, and its structure was optimized. Molecular docking simulation showed the interactions of the two compounds, with the amino acid residues responsible for CP-CP interactions. Catechinic acid showed the best binding energy value in comparison with ribavirin, an anti-tobamovirus agent.
Assuntos
Antivirais/farmacologia , Combretum/química , Doenças das Plantas/prevenção & controle , Solanum lycopersicum/efeitos dos fármacos , Tobamovirus/efeitos dos fármacos , Antivirais/química , Homeostase , Solanum lycopersicum/virologia , Metanol/química , Testes de Sensibilidade Microbiana , Modelos Moleculares , Simulação de Acoplamento Molecular , Oxirredução , Doenças das Plantas/virologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Folhas de Planta/química , Vírus de Plantas/química , Vírus de Plantas/efeitos dos fármacos , Vírus de Plantas/patogenicidade , Tobamovirus/química , Tobamovirus/patogenicidadeRESUMO
Quorum-sensing (QS) is a regulatory mechanism in bacterial communication, important for pathogenesis control. The search for small molecules active as quorum-sensing inhibitors (QSI) that can synergize with antibiotics is considered a good strategy to counteract the problem of antibiotic resistance. Here the antimicrobial labdane diterpenoids sclareol (1) and manool (2) extracted from Salvia tingitana were considered as potential QSI against methicillin-resistant Staphylococcus aureus. Only sclareol showed synergistic activity with clindamycin. The quantification of these compounds by LC-MS analysis in the organs and in the calli of S. tingitana showed that sclareol is most abundant in the flower spikes and is produced by calli, while manool is the major labdane of the roots, and is abundant also in the leaves. Other metabolites of the roots were abietane diterpenoids, common in Salvia species, and pentacyclic triterpenoids, bearing a γ-lactone moiety, previously undescribed in Salvia. Docking simulations suggested that 1 and 2 bind to key residues, involved in direct interactions with DNA. They may prevent accessory gene regulator A (AgrA) binding to DNA or AgrA activation upon phosphorylation, to suppress virulence factor expression. The antimicrobial activity of these two compounds probably achieves preventing upregulation of the accessory gene regulator (agr)-regulated genes.
Assuntos
Antibacterianos/farmacologia , Clindamicina/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Extratos Vegetais/farmacologia , Salvia/química , Antibacterianos/química , Relação Dose-Resposta a Droga , Testes de Sensibilidade Microbiana , Conformação Molecular , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Estrutura Molecular , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/química , Percepção de Quorum/efeitos dos fármacos , Relação Estrutura-AtividadeRESUMO
Peripheral myelin protein 2 (PMP2) is a small protein located on the cytoplasmic side of compact myelin, involved in the lipids transport and in the myelination process. In the last years few families affected with demyelinating Charcot-Marie-Tooth neuropathy (CMT1), caused by PMP2 mutations, have been identified. In this study we describe the first case of a PMP2 in-frame deletion. PMP2 was analyzed by direct sequencing after exclusion of the most frequent CMT-associated genes by using a next generation sequencing (NGS) genes panel. Sanger sequencing was used for family's segregation analysis. Molecular modeling analysis was used to evaluate the mutation impact on the protein structure. A novel PMP2: p.I50del has been identified in a child with early onset CMT1 and in three affected family members. All family members show an early onset demyelinating neuropathy without other distinguish features. Molecular modeling analysis and in silico evaluations do not suggest a strong impact on the overall protein structure, but a most likely altered protein function. This study suggests the importance to add PMP2 in CMT NGS genes panels or, at most, to test it after major CMT1 genes exclusion, due to the lack of diagnostic-addressing additional features.
Assuntos
Doença de Charcot-Marie-Tooth/genética , Doença de Charcot-Marie-Tooth/fisiopatologia , Proteína P2 de Mielina/genética , Adulto , Idade de Início , Feminino , Humanos , Lactente , Masculino , Linhagem , Adulto JovemRESUMO
Cystic fibrosis (CF) is the autosomal recessive disorder most recurrent in Caucasian populations. Different mutations involving the cystic fibrosis transmembrane regulator protein (CFTR) gene, which encodes the CFTR channel, are involved in CF. A number of life-prolonging therapies have been conceived and deeply investigated to combat this disease. Among them, the administration of the so-called CFTR modulators, such as correctors and potentiators, have led to quite beneficial effects. Recently, based on QSAR (quantitative structure activity relationship) studies, we reported the rational design and synthesis of compound 2, an aminoarylthiazole-VX-809 hybrid derivative exhibiting promising F508del-CFTR corrector ability. Herein, we explored the docking mode of the prototype VX-809 as well as of the aforementioned correctors in order to derive useful guidelines for the rational design of further analogues. In addition, we refined our previous QSAR analysis taking into account our first series of in-house hybrids. This allowed us to optimize the QSAR model based on the chemical structure and the potency profile of hybrids as F508del-CFTR correctors, identifying novel molecular descriptors explaining the SAR of the dataset. This study is expected to speed up the discovery process of novel potent CFTR modulators.
Assuntos
Aminopiridinas/química , Aminopiridinas/farmacologia , Benzodioxóis/química , Benzodioxóis/farmacologia , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Fibrose Cística/tratamento farmacológico , Simulação de Acoplamento Molecular , Mutação , Relação Quantitativa Estrutura-Atividade , Fibrose Cística/genética , Fibrose Cística/patologia , Regulador de Condutância Transmembrana em Fibrose Cística/química , HumanosRESUMO
Cystic fibrosis transmembrane conductance regulator (CFTR)-rescuing drugs have already transformed cystic fibrosis (CF) from a fatal disease to a treatable chronic condition. However, new-generation drugs able to bind CFTR with higher specificity/affinity and to exert stronger therapeutic benefits and fewer side effects are still awaited. Computational methods and biosensors have become indispensable tools in the process of drug discovery for many important human pathologies. Instead, they have been used only piecemeal in CF so far, calling for their appropriate integration with well-tried CF biochemical and cell-based models to speed up the discovery of new CFTR-rescuing drugs. This review will give an overview of the available structures and computational models of CFTR and of the biosensors, biochemical and cell-based assays already used in CF-oriented studies. It will also give the reader some insights about how to integrate these tools as to improve the efficiency of the drug discovery process targeted to CFTR.
Assuntos
Regulador de Condutância Transmembrana em Fibrose Cística/química , Regulador de Condutância Transmembrana em Fibrose Cística/efeitos dos fármacos , Descoberta de Drogas/métodos , Técnicas Biossensoriais , Biologia Computacional , Fibrose Cística/tratamento farmacológico , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Humanos , Modelos Moleculares , Conformação ProteicaRESUMO
Breakthroughs in Medicinal Chemistry [...].
Assuntos
Descoberta de Drogas/métodos , Animais , Química Farmacêutica , Humanos , Terapia de Alvo Molecular , Preparações Farmacêuticas , Relação Estrutura-AtividadeRESUMO
A series of sulfenamide and sulfonamide derivatives was synthesized and evaluated for the affinity at CB1 and CB2 receptors. The N-bornyl-S-(5,6-di-p-tolylpyridazin-3-yl)-sulfenamide, compound 11, displayed good affinity and high selectivity for CB1 receptors (Ki values of 44.6â¯nM for CB1 receptors and >40⯵M for CB2 receptors, respectively). The N-isopinocampheyl-sulfenamide 12 and its sulfonamide analogue 22 showed similar selectivity for CB1 receptors with Ki values of 75.5 and 73.2â¯nM, respectively. These novel compounds behave as antagonists/inverse agonists at CB1 receptor in the [35S]-GTPγS binding assays, and none showed adequate predictive blood-brain barrier permeation, exhibiting low estimated LD50. However, testing compound 12 in a supraspinal analgesic test (hot-plate) revealed that it was as effective as the classic CB1 receptor antagonist rimonabant, in reversing the analgesic effect of a cannabinoid agonist.
Assuntos
Piridazinas/farmacologia , Receptor CB1 de Canabinoide/antagonistas & inibidores , Sulfamerazina/farmacologia , Sulfonamidas/farmacologia , Relação Dose-Resposta a Droga , Humanos , Ligantes , Simulação de Acoplamento Molecular , Estrutura Molecular , Piridazinas/química , Relação Estrutura-Atividade , Sulfamerazina/síntese química , Sulfamerazina/química , Sulfonamidas/síntese química , Sulfonamidas/químicaRESUMO
Cystic fibrosis (CF) is mainly caused by the deletion of Phe 508 (ΔF508) in the cystic fibrosis transmembrane conductance regulator (CFTR) protein that is thus withheld in the endoplasmic reticulum and rapidly degraded by the ubiquitin/proteasome system. New drugs able to rescue ΔF508-CFTR trafficking are eagerly awaited. An integrated bioinformatics and surface plasmon resonance (SPR) approach was here applied to investigate the rescue mechanism(s) of a series of CFTR-ligands including VX809, VX770 and some aminoarylthiazole derivatives (AAT). Computational studies tentatively identified a large binding pocket in the ΔF508-CFTR nucleotide binding domain-1 (NBD1) and predicted all the tested compounds to bind to three sub-regions of this main pocket. Noticeably, the known CFTR chaperone keratin-8 (K8) seems to interact with some residues located in one of these sub-pockets, potentially interfering with the binding of some ligands. SPR results corroborated all these computational findings. Moreover, for all the considered ligands, a statistically significant correlation was determined between their binding capability to ΔF508-NBD1 measured by SPR and the pockets availability measured by computational studies. Taken together, these results demonstrate a strong agreement between the in silico prediction and the SPR-generated binding data, suggesting a path to speed up the identification of new drugs for the treatment of cystic fibrosis.
Assuntos
Regulador de Condutância Transmembrana em Fibrose Cística/química , Tiazóis/química , Sítios de Ligação , Biologia Computacional , Fibrose Cística/tratamento farmacológico , Avaliação Pré-Clínica de Medicamentos , Humanos , Simulação de Dinâmica Molecular , Ligação Proteica , Ressonância de Plasmônio de SuperfícieRESUMO
Phosphodiesterase 4 (PDE4) inhibitors have attractive therapeutic potential in respiratory, inflammatory, metabolic and CNS disorders. The present work details the design, chemical exploration and biological profile of a novel PDE4 inhibitor chemotype. A diazepinone ring was identified as an under-represented heterocyclic system fulfilling a set of PDE4 structure-based design hypotheses. Rapid exploration of the structure activity relationships for the series was enabled by robust and scalable two/three-steps parallel chemistry protocols. The resulting compounds demonstrated PDE4 inhibitory activity in cell free and cell-based assays comparable to the Zardaverine control used, suggesting potential avenues for their further development.
Assuntos
Azepinas/farmacologia , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/metabolismo , Desenho de Fármacos , Inibidores da Fosfodiesterase 4/farmacologia , Azepinas/síntese química , Azepinas/química , Relação Dose-Resposta a Droga , Humanos , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Lipopolissacarídeos/antagonistas & inibidores , Lipopolissacarídeos/farmacologia , Estrutura Molecular , Inibidores da Fosfodiesterase 4/síntese química , Inibidores da Fosfodiesterase 4/química , Relação Estrutura-Atividade , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Fator de Necrose Tumoral alfa/biossínteseRESUMO
The 5-hydroxytryptamine (5-HT1A) receptors represent an attractive target in drug discovery. In particular, 5-HT1A agonists and partial agonists are deeply investigated for their potential role in the treatment of anxiety, depression, ischaemic brain disorder and more recently, of pain. On the other hand, 5-HT1A antagonists have been revealed promising compounds in cognition disorders and, lately, in cancer. Thus, the discovery of 5HT1A ligands is nowadays an appealing research activity in medicinal chemistry. In this work, Comparative Molecular Fields Analysis (CoMFA) and Comparative Molecular Similarity Index Analysis (CoMSIA) were applied on an in-house library of 5-HT1A ligands bearing different chemical scaffolds in order to elucidate their affinity and selectivity for the target. Following this procedure, a number of structural modifications have been drawn for the development of much more effective 5-HT1AR ligands. [Formula: see text].
Assuntos
Receptor 5-HT1A de Serotonina/metabolismo , Antagonistas do Receptor 5-HT1 de Serotonina/química , Antagonistas do Receptor 5-HT1 de Serotonina/farmacologia , Relação Dose-Resposta a Droga , Humanos , Ligantes , Modelos Moleculares , Estrutura Molecular , Relação Quantitativa Estrutura-Atividade , Relação Estrutura-AtividadeRESUMO
Respiratory syncytial virus (RSV) has been identified as a main cause of hospitalisation in infants and children. To date, the current therapeutic arsenal is limited to ribavirin and palivizumab with variable efficacy. In this work, starting from a number of in-house series of previously described anti-RSV agents based on the benzimidazole scaffold, with the aim at gaining a better understanding of the related chemical features involved in potency and safety profiles, we applied a computational study including two focussed comparative molecular fields analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA). The results allowed us to derive useful suggestions for the design of derivatives and also to set up statistical models predicting the potency and selectivity index (SI = CC50/EC50) of any new analogue prior to synthesis. Accordingly, here, we discuss preliminary results obtained through the applied exhaustive QSAR analyses, leading to design and synthesise more effective anti-RSV agents.
Assuntos
Antivirais/farmacologia , Benzimidazóis/farmacologia , Vírus Sinciciais Respiratórios/efeitos dos fármacos , Infecções por Respirovirus/tratamento farmacológico , Animais , Antivirais/síntese química , Antivirais/química , Benzimidazóis/síntese química , Benzimidazóis/química , Linhagem Celular , Chlorocebus aethiops , Relação Dose-Resposta a Droga , Humanos , Testes de Sensibilidade Microbiana , Modelos Moleculares , Estrutura Molecular , Relação Quantitativa Estrutura-Atividade , Células VeroRESUMO
Positive inotropic agents are fundamental in the treatment of heart failure; however, their arrhythmogenic liability and the increased myocardial oxygen demand strongly limit their therapeutic utility. Pursuing our study on cardiovascular activities of lupin alkaloid derivatives, several 2-(4-substituted-phenyl)-2-dehydrosparteines and 2-(4-substituted-phenyl)sparteines were prepared and tested for inotropic and chronotropic activities on isolated guinea pig atria. Four compounds (6b, 6e, 7b, and 7f) exhibited significant inotropism that, at the higher concentrations, was followed by negative inotropism or toxicity. Compound 7e (2-(4-tolyl)sparteine) exhibited a steep dose-depending inotropic activity up to the highest concentration tested (300 µM) with an Emax of 116.5 ± 3.4% of basal force, proving less potent but much more active in comparison to the highest concentrations tested of digoxin and milrinone having Emax of 87.5 ± 3.1% and 52.2 ± 1.1%, respectively. Finally, docking studies suggested that the relevant sparteine derivatives could target the sigma-1 receptor, whose involvement in cardiac activity is well documented.
Assuntos
Cardiotônicos/química , Cardiotônicos/farmacologia , Esparteína/química , Esparteína/farmacologia , Animais , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Avaliação Pré-Clínica de Medicamentos , Cobaias , Técnicas In Vitro , Masculino , Camundongos , Simulação de Acoplamento Molecular , Espectroscopia de Prótons por Ressonância Magnética , RatosRESUMO
Genetic discoveries in amyotrophic lateral sclerosis (ALS) have a significant impact on deciphering molecular mechanisms of motor neuron degeneration but, despite recent advances, the etiology of most sporadic cases remains elusive. Several cellular mechanisms contribute to the motor neuron degeneration in ALS, including RNA metabolism, cellular interactions between neurons and nonneuronal cells, and seeding of misfolded protein with prion-like propagation. In this scenario, the importance of protein turnover and degradation in motor neuron homeostasis gained increased recognition. In this study, we evaluated the role of the candidate gene HSPB1, a molecular chaperone involved in several proteome-maintenance functions. In a cohort of 247 unrelated Italian ALS patients, we identified two variants (c.570G>C, p.Gln190His and c.610dupG, p.Ala204Glyfs* 6). Functional characterization of the p.Ala204Glyfs* 6 demonstrated that the mutant protein alters HSPB1 dynamic equilibrium, sequestering the wild-type protein in a stable dimer and resulting in a loss of chaperone-like activity. Our results underline the relevance of identifying rare but pathogenic variations in sporadic neurodegenerative diseases, suggesting a possible correlation between specific pathomechanisms linked to HSPB1 mutations and the associated neurological phenotype. Our study provides additional lines of evidence to support the involvement of HSPB1 in the pathogenesis of sporadic ALS.
Assuntos
Esclerose Lateral Amiotrófica/genética , Proteínas de Choque Térmico HSP27/genética , Proteínas de Choque Térmico HSP27/metabolismo , Mutação , Idoso , Esclerose Lateral Amiotrófica/metabolismo , Feminino , Predisposição Genética para Doença , Proteínas de Choque Térmico HSP27/química , Proteínas de Choque Térmico , Humanos , Itália , Pessoa de Meia-Idade , Chaperonas Moleculares , Multimerização ProteicaRESUMO
Pyrazolo[5,1-f][1,6]naphthyridine-carboxamide derivatives were synthesized and evaluated for the affinity at CB1 and CB2 receptors. Based on the AgOTf and proline-cocatalyzed multicomponent methodology, the ethyl 5-(p-tolyl)pyrazolo[5,1-f][1,6]naphthyridine-2-carboxylate (12) and ethyl 5-(2,4-dichlorophenyl)pyrazolo[5,1-f][1,6]naphthyridine-2-carboxylate (13) intermediates were synthesized from the appropriate o-alkynylaldehydes, p-toluenesulfonyl hydrazide and ethyl pyruvate. Most of the novel compounds feature a p-tolyl (8a-i) or a 2,4-dichlorophenyl (8j) motif at the C5-position of the tricyclic pyrazolo[5,1-f][1,6]naphthyridine scaffold. Structural variation on the carboxamide moiety at the C2-position includes basic monocyclic, terpenoid and adamantine-based amines. Among these derivatives, compound 8h (N-adamant-1-yl-5-(p-tolyl)pyrazolo[5,1-f][1,6]naphthyridine-2-carboxamide) exhibited the highest CB2 receptor affinity (Ki=33nM) and a high degree of selectivity (KiCB1/KiCB2=173:1), whereas a similar trend in the near nM range was seen for the bornyl analogue (compound 8f, Ki=53nM) and the myrtanyl derivative 8j (Ki=67nM). Effects of 8h, 8f and 8j on forskolin-stimulated cAMP levels were determined, showing antagonist/inverse agonist properties for such compounds. Docking studies conducted for these derivatives and the reference antagonist/inverse agonist compound 4 (SR144528) disclosed the specific pattern of interactions probably related to the pyrazolo[5,1-f][1,6]naphthyridine scaffold as CB2 inverse agonists.
Assuntos
Modelos Moleculares , Naftiridinas/química , Naftiridinas/farmacologia , Receptor CB2 de Canabinoide/agonistas , Receptor CB2 de Canabinoide/antagonistas & inibidores , Relação Dose-Resposta a Droga , Humanos , Estrutura Molecular , Naftiridinas/síntese química , Receptor CB1 de Canabinoide/agonistas , Receptor CB1 de Canabinoide/antagonistas & inibidores , Relação Estrutura-AtividadeRESUMO
PDE4 inhibitors have been largely studied because of their promising therapeutic effects concerning inflammation and neurodegenerative dysfunctions, such as depression, schizophrenia and Alzheimer's diseases. In this context, the PDE4B isoform proved to be particularly involved in the activation of inflammatory responses, while the PDE4D subfamily is more associated with neuropathologies. The clinical use of PDE4 inhibitors was restricted by the presence of prominent side effects probably due to their non-specific action across the different isoforms. Therefore, this work deals with the development of 3D-QSAR models, supported by molecular docking studies, to identify the key requirements underlying selective PDE4B or PDE4D inhibition. The results highlighted the ligand-based approach as a promising tool to guide the rational design of novel PDE4 inhibitors endowed with high affinity and selectivity profiles. The alignment of compound 1-85 and the model A statistical results are depicted.