Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 70
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Enzyme Inhib Med Chem ; 36(1): 1783-1797, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34340630

RESUMO

Carbonic Anhydrase Activators (CAAs) could represent a novel approach for the treatment of Alzheimer's disease, ageing, and other conditions that require remedial achievement of spatial learning and memory therapy. Within a research project aimed at developing novel CAAs selective for certain isoforms, three series of indole-based derivatives were investigated. Enzyme activation assay on human CA I, II, VA, and VII isoforms revealed several effective micromolar activators, with promising selectivity profiles towards the brain-associated cytosolic isoform hCA VII. Molecular modelling studies suggested a theoretical model of the complex between hCA VII and the new activators and provide a possible explanation for their modulating as well as selectivity properties. Preliminary biological evaluations demonstrated that one of the most potent CAA 7 is not cytotoxic and is able to increase the release of the brain-derived neurotrophic factor (BDNF) from human microglial cells, highlighting its possible application in the treatment of CNS-related disorders.


Assuntos
Anidrases Carbônicas/efeitos dos fármacos , Ativadores de Enzimas/farmacologia , Indóis/farmacologia , Isoenzimas/efeitos dos fármacos , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Anidrases Carbônicas/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Ativação Enzimática , Ativadores de Enzimas/química , Ensaio de Imunoadsorção Enzimática/métodos , Humanos , Indóis/química , Isoenzimas/metabolismo , Microglia/citologia , Microglia/efeitos dos fármacos , Modelos Moleculares , Espectroscopia de Prótons por Ressonância Magnética , Especificidade por Substrato
2.
Eur J Med Chem ; 221: 113532, 2021 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-34052717

RESUMO

Long-term survivors of glioblastoma multiforme (GBM) are at high risk of developing second primary neoplasms, including leukemia. For these patients, the use of classic tyrosine kinase inhibitors (TKIs), such as imatinib mesylate, is strongly discouraged, since this treatment causes a tremendous increase of tumor and stem cell migration and invasion. We aimed to develop agents useful for the treatment of patients with GBM and chronic myeloid leukemia (CML) using an alternative mechanism of action from the TKIs, specifically based on the inhibition of tubulin polymerization. Compounds 7 and 25, as planned, not only inhibited tubulin polymerization, but also inhibited the proliferation of both GMB and CML cells, including those expressing the T315I mutation, at nanomolar concentrations. In in vivo experiments in BALB/cnu/nu mice injected subcutaneously with U87MG cells, in vivo, 7 significantly inhibited GBM cancer cell proliferation, in vivo tumorigenesis, and tumor growth, tumorigenesis and angiogenesis. Compound 7 was found to block human topoisomerase II (hTopoII) selectively and completely, at a concentration of 100 µM.


Assuntos
Antineoplásicos/farmacologia , Descoberta de Drogas , Glioblastoma/tratamento farmacológico , Compostos Heterocíclicos/farmacologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Metano/farmacologia , Moduladores de Tubulina/farmacologia , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Glioblastoma/metabolismo , Glioblastoma/patologia , Compostos Heterocíclicos/síntese química , Compostos Heterocíclicos/química , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Metano/análogos & derivados , Metano/química , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Estrutura Molecular , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Polimerização/efeitos dos fármacos , Relação Estrutura-Atividade , Tubulina (Proteína)/metabolismo , Moduladores de Tubulina/síntese química , Moduladores de Tubulina/química , Células Tumorais Cultivadas
3.
Int J Mol Sci ; 22(6)2021 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-33803741

RESUMO

Neuroactive steroids are potent modulators of microglial functions and are capable of counteracting their excessive reactivity. This action has mainly been ascribed to neuroactive steroids released from other sources, as microglia have been defined unable to produce neurosteroids de novo. Unexpectedly, immortalized murine microglia recently exhibited this de novo biosynthesis; herein, de novo neurosteroidogenesis was characterized in immortalized human microglia. The results demonstrated that C20 and HMC3 microglial cells constitutively express members of the neurosteroidogenesis multiprotein machinery-in particular, the transduceosome members StAR and TSPO, and the enzyme CYP11A1. Moreover, both cell lines produce pregnenolone and transcriptionally express the enzymes involved in neurosteroidogenesis. The high TSPO expression levels observed in microglia prompted us to assess its role in de novo neurosteroidogenesis. TSPO siRNA and TSPO synthetic ligand treatments were used to reduce and prompt TSPO function, respectively. The TSPO expression downregulation compromised the de novo neurosteroidogenesis and led to an increase in StAR expression, probably as a compensatory mechanism. The pharmacological TSPO stimulation the de novo neurosteroidogenesis improved in turn the neurosteroid-mediated release of Brain-Derived Neurotrophic Factor. In conclusion, these results demonstrated that de novo neurosteroidogenesis occurs in human microglia, unravelling a new mechanism potentially useful for future therapeutic purposes.


Assuntos
Microglia/metabolismo , Neuroesteroides/metabolismo , Receptores de GABA/metabolismo , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Linhagem Celular , Regulação da Expressão Gênica , Humanos , Neuroesteroides/química , Pregnenolona/química , Pregnenolona/metabolismo
4.
Eur J Med Chem ; 209: 112924, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33081988

RESUMO

The Translocator Protein 18 kDa (TSPO) has been discovered in 1977 as an alternative binding site for the benzodiazepine diazepam. It is an evolutionary well-conserved and tryptophan-rich 169-amino acids protein with five alpha helical transmembrane domains stretching the outer mitochondrial membrane, with the carboxyl-terminus in the cytosol and a short amino-terminus in the intermembrane space of mitochondrion. At this level, together with the voltage-dependent anion channel (VDAC) and the adenine nucleotide translocase (ANT), it forms the mitochondrial permeability transition pore (MPTP). TSPO expression is ubiquitary, with higher levels in steroid producing tissues; in the central nervous system, it is mainly expressed in glial cells and in neurons. TSPO is implicated in a variety of fundamental cellular processes including steroidogenesis, heme biosynthesis, mitochondrial respiration, mitochondrial membrane potential, cell proliferation and differentiation, cell life/death balance, oxidative stress. Altered TSPO expression has been found in some pathological conditions. In particular, high TSPO expression levels have been documented in cancer, neuroinflammation, and brain injury. Conversely, low TSPO expression levels have been evidenced in anxiety disorders. Therefore, TSPO is not only an interesting drug target for therapeutic purpose (anticonvulsant, anxiolytic, etc.), but also a valid diagnostic marker of related-diseases detectable by fluorescent or radiolabeled ligands. The aim of this report is to present an update of previous reviews dealing with the medicinal chemistry of TSPO and to highlight the most outstanding advances in the development of TSPO ligands as potential therapeutic or diagnostic tools, especially referring to the last five years.


Assuntos
Ansiolíticos/química , Anticonvulsivantes/química , Benzodiazepinas/química , Diazepam/química , Receptores de GABA/metabolismo , Sequência de Aminoácidos , Animais , Ansiolíticos/farmacologia , Anticonvulsivantes/farmacologia , Apoptose/efeitos dos fármacos , Benzimidazóis/química , Proliferação de Células/efeitos dos fármacos , Humanos , Imidazóis/química , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/metabolismo , Translocases Mitocondriais de ADP e ATP/metabolismo , Membranas Mitocondriais/metabolismo , Poro de Transição de Permeabilidade Mitocondrial/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ligação Proteica , Piridinas/química , Quinolinas/química , Receptores de GABA/genética , Relação Estrutura-Atividade , Canais de Ânion Dependentes de Voltagem/metabolismo
5.
Biochem Pharmacol ; 177: 114015, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32387458

RESUMO

The outer mitochondrial membrane 18-kDa translocator protein (TSPO) is highly conserved in organisms of different species and ubiquitously expressed throughout tissues, including the nervous system. In the healthy adult brain, TSPO expression levels are low and promptly modulated under different pathological conditions, such as cancer, inflammatory states, and neurological and psychiatric disorders. Not surprisingly, several endogenous and synthetic molecules capable of binding TSPO have been proposed as drugs or diagnostic tools for brain diseases. The most studied biochemical function of TSPO is cholesterol translocation into mitochondria, which in turn affects the synthesis of steroids in the periphery and neurosteroids in the brain. In the last 30 years, roles for TSPO have also been suggested in other cellular processes, such as heme synthesis, apoptosis, autophagy, calcium signalling and reactive oxygen species production. Herein, we provide an overview of TSPO associations with different proteins, focusing particular attention on their related functions. Furthermore, recent TSPO-targeted therapeutic interventions are explored and discussed as prospect for innovative treatments in mental and brain diseases.


Assuntos
Encefalopatias/tratamento farmacológico , Receptores de GABA/química , Receptores de GABA/metabolismo , Animais , Transtornos de Ansiedade/tratamento farmacológico , Transtornos de Ansiedade/metabolismo , Apoptose/fisiologia , Autofagia/fisiologia , Encefalopatias/metabolismo , Cálcio/metabolismo , Metabolismo Energético , Heme/metabolismo , Humanos , Mitocôndrias/metabolismo , Terapia de Alvo Molecular/métodos , Espécies Reativas de Oxigênio/metabolismo
6.
Oxid Med Cell Longev ; 2020: 4650207, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32047577

RESUMO

Sirtuin 1 (SIRT1) enzyme plays a pivotal role in the regulation of many physiological functions. In particular, it is implicated in ageing-related diseases, such as cardiac hypertrophy, myocardial infarct, and endothelial dysfunction; moreover, its expression decreases with age. Therefore, an effective strategy to extend the lifespan and improve cardiovascular function is the enhancement of the expression/activity of SIRT1 with exogenous agents. The Citrus flavonoid naringenin (NAR) presents structural similarity with the natural SIRT1 activator resveratrol. In this study, we demonstrate through in vitro assays that NAR significantly activates SIRT1 enzyme and shows antisenescence effects. The binding mode of NAR into SIRT1 was detailed investigated through in silico studies. Moreover, chronic administration (for six months) of NAR (100 mg/kg/day) to 6-month-old mice leads to an enhancement of SIRT1 expression and a marked reduction of reactive oxygen species production in myocardial tissue. Furthermore, at the end of the treatment, the plasma levels of two well-known markers of cardiovascular inflammation, TNF-α and IL6, are significantly reduced in 12-month-old mice treated with NAR, as well as the cardiovascular risk (total cholesterol/HDL ratio) compared to control mice. Finally, the age-associated fibrotic remodeling, which is well detected through a Mallory trichrome staining in the vehicle-treated 12-month-old mice, is significantly reduced by the chronic treatment with NAR. Moreover, an improvement of myocardium functionality is highlighted by the enhancement of citrate synthase activity and stabilization of the mitochondrial membrane potential after NAR treatment. Taken together, these results suggest that a nutraceutical approach with NAR may have positive impacts on many critical hallmarks of myocardial senescence, contributing to improve the cardiac performance in aged subjects.


Assuntos
Envelhecimento/fisiologia , Antioxidantes/uso terapêutico , Flavanonas/uso terapêutico , Miocárdio/patologia , Sirtuína 1/metabolismo , Animais , Linhagem Celular , Senescência Celular/efeitos dos fármacos , Citrus , Citoproteção , Modelos Animais de Doenças , Humanos , Interleucina-6/metabolismo , Camundongos , Ligação Proteica , Ratos , Espécies Reativas de Oxigênio/metabolismo , Sirtuína 1/genética , Fator de Necrose Tumoral alfa/metabolismo
7.
Eur J Med Chem ; 185: 111828, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31727471

RESUMO

Novel 3-aroyl-1,4-diarylpyrrole derivatives were synthesized to explore structure-activity relationships at the phenyls at positions 1 and 4 of the pyrrole. The presence of amino phenyl rings at positions 1 and 4 of the pyrrole ring were found to be a crucial requirement for potent antitumor activity. Several compounds strongly inhibited tubulin assembly through binding to the colchicine site. Compounds 42, 44, 48, 62 and 69 showed antitumor activity with low nanomolar IC50 values in several cancer cell lines. Compound 48 was generally more effective as an inhibitor of glioblastoma, colorectal and urinary bladder cancer cell lines; 69 consistently inhibited CML cell lines and demonstrated superiority in nilotinib and imatinib resistant LAMA84-R and KBM5-T315I cells. In animal models, compound 48 exhibited significant inhibition of the growth of T24 bladder carcinoma and ES-2 ovarian clear cell carcinoma tumors. Compounds 48 and 69 represent robust lead compounds for the design of new broad-spectrum anticancer agents active in different types of solid and hematological tumors.


Assuntos
Antineoplásicos/farmacologia , Neoplasias Encefálicas/tratamento farmacológico , Glioblastoma/tratamento farmacológico , Neoplasias Hematológicas/tratamento farmacológico , Pirróis/farmacologia , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Neoplasias Encefálicas/patologia , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Glioblastoma/patologia , Neoplasias Hematológicas/patologia , Humanos , Injeções Intraperitoneais , Injeções Subcutâneas , Camundongos , Camundongos Endogâmicos BALB C , Estrutura Molecular , Imagem Óptica , Pirróis/administração & dosagem , Pirróis/química , Relação Estrutura-Atividade , Células Tumorais Cultivadas
8.
ACS Chem Neurosci ; 10(8): 3805-3814, 2019 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-31268683

RESUMO

Translocator protein 18 kDa (TSPO) is a validated pharmacological target for the development of new treatments for neurological disorders. N,N-Dialkyl-2-phenylindol-3-ylglyoxylamides (PIGAs) are effective TSPO modulators and potentially useful therapeutics for the treatment of anxiety, central nervous system pathologies featuring astrocyte loss, and inflammatory-based neuropathologies. For this class of compounds, no correlation exists between the TSPO binding affinity and the corresponding functional efficacy. Rather, their biological effectiveness correlates with the kinetics of the unbinding events and more specifically with the residence time (RT). So far, the structural reasons for the different recorded RT of congeneric PIGAs remain elusive. Here, to understand the different kinetics of PIGAs, their unbinding paths were studied by employing enhanced-sampling molecular dynamics simulations. Results of these studies revealed how subtle structural differences between PIGAs have a substantial effect on the unbinding energetics. In particular, during the egress from the TSPO binding site, slow-dissociating PIGAs find tight interactions with the protein LP1 region thereby determining a long RT. Further support to these findings was achieved by in vivo studies, which demonstrated how the anxiolytic effect observed for the inspected PIGAs correlated with their RT to TSPO.


Assuntos
Proteínas de Transporte/metabolismo , Receptores de GABA-A/metabolismo , Animais , Ansiolíticos/farmacologia , Sítios de Ligação , Simulação por Computador , Masculino , Simulação de Dinâmica Molecular , Ligação Proteica , Ratos , Ratos Sprague-Dawley
9.
Chem Asian J ; 13(21): 3321-3327, 2018 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-30369074

RESUMO

Novel boron-rich, carboranyl-indole carboxamide ligands were prepared and found to effectively target the 18 kDa translocator protein (TSPO), an upregulated mitochondrial membrane-bound protein which has been observed in variety of tumor cell lines and its expression appears to be proportional to the degree of tumorigenicity, emphasizing a key role in cancer cell proliferation. Both boronated compounds displayed remarkably high affinities for the TSPO. In addition, the in vitro uptake of these compounds into T98G human glioma cells was found to be 25- to 100-fold greater than that of clinical boron neutron capture therapy (BNCT) agents.

10.
Oxid Med Cell Longev ; 2018: 9395804, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30116497

RESUMO

Aging is one of the main risk factor for the onset of cardiovascular diseases; one of the possible explanations could be linked to the age-associated overproduction of free radicals. This increase of oxidative stress can be overcome with a high intake of food antioxidants. In this context, a number of studies have been addressed to assess the antiaging potential of natural antioxidant compounds. Recently, it has been shown that the juice of bergamot (Citrus bergamia Risso et Poiteau), a fruit mostly produced in the Ionian coastal areas of Southern Italy (Calabria), is a valuable source of health-promoting constituents with, among other, antioxidant properties. In order to investigate the potential antiaging effects of this Mediterranean natural antioxidant source, bergamot juices of three different cultivars ("fantastico," "femminello," and "castagnaro") were herein characterized by the mean of high-performance liquid chromatography-photodiode array-electrospray ionization-tandem mass spectrometry. Then, juices were investigated for the evaluation of total polyphenolic and flavonoid contents, cell-free model antioxidant activities, and in vitro antiaging properties on two different cellular models of induced myocardial senescence. The best performing juice was also assessed in vivo. The phytochemical profiles confirmed that juices were rich in flavonoids, both flavone and flavanone glycosides. In addition, two limonoid glycosides were also identified in all cultivars. Each cultivar showed different phenolic and flavonoid contents. In tube results showed the juice robust antioxidant activities that correlate with their phenolic and flavonoid contents. Moreover, for the first time, the ability of juice to counteract the chemical-induced senescence was here demonstrated in both cellular models. Lastly, the in vivo data obtained from mouse hearts evidenced an increase in transcription of genes involved in antiaging and antioxidant responses. The overall results suggest that bergamot juice exerts antioxidant and antisenescence effects, making it useful for nutraceutical purposes.


Assuntos
Envelhecimento/efeitos dos fármacos , Antioxidantes/química , Bebidas/análise , Citrus/química , Humanos
11.
PLoS One ; 13(7): e0200924, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30048487

RESUMO

The stress hormone cortisol has been recognized as a coordinator of immune response. However, its different ability to modulate the release of inflammatory mediators in males and females has not been clarified yet. Indeed, the dissection of cortisol specific actions may be difficult due to the complex hormonal and physio-pathological individual status. Herein, the release of inflammatory mediators following increasing cortisol concentrations was investigated in an in vitro model of primary human male and female lymphomonocytes. The use of a defined cellular model to assess sex differences in inflammatory cytokine secretion could be useful to exclude the effects of divergent and fluctuating sex hormone levels occurring in vivo. Herein, the cells were challenged with cortisol concentrations resembling the plasma levels achieving in physiological and stressful conditions. The production of cytokines and other molecules involved in inflammatory process was determined. In basal conditions, male cells presented higher levels of some pro-inflammatory molecules (NF-kB and IDO-1 mRNAs, IL-6 and kynurenine) than female cells. Following cortisol exposure, the levels of the pro-inflammatory cytokines, IL-6 and IL-8, were increased in male cells. Conversely, in female cells IL-6 release was unchanged and IL-8 levels were decreased. Anti-inflammatory cytokines, IL-4 and IL-10, did not change in male cells and increased in female cells. Interestingly, kynurenine levels were higher in female cells than in male cells following cortisol stimulus. These results highlighted that cortisol differently affects male and female lymphomonocytes, shifting the cytokine release in favour of a pro-inflammatory pattern in male cells and an anti-inflammatory secretion profile in female cells, opening the way to study the influences of other stressful factors involved in the neurohumoral changes occurring in the response to stress conditions.


Assuntos
Citocinas/metabolismo , Hidrocortisona/farmacologia , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Caracteres Sexuais , Citocinas/biossíntese , Relação Dose-Resposta a Droga , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Masculino
12.
Eur J Med Chem ; 152: 283-297, 2018 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-29730191

RESUMO

We designed new 3-arylthio- and 3-aroyl-1H-indole derivatives 3-22 bearing a heterocyclic ring at position 5, 6 or 7 of the indole nucleus. The 6- and 7-heterocyclyl-1H-indoles showed potent inhibition of tubulin polymerization, binding of colchicine to tubulin and growth of MCF-7 cancer cells. Compounds 13 and 19 inhibited a panel of cancer cells and the NCI/ADR-RES multidrug resistant cell line at low nanomolar concentrations. Compound 13 at 50 nM induced 77% G2/M in HeLa cells, and at 20 nM caused 50% stable arrest of mitosis. As an inhibitor of HepG2 cells (IC50 = 20 nM), 13 was 4-fold superior to 19. Compound 13 was a potent inhibitor of the human U87MG glioblastoma cells at nanomolar concentrations, being nearly one order of magnitude superior to previously reported arylthioindoles. The present results highlight 13 as a robust scaffold for the design of new anticancer agents.


Assuntos
Antineoplásicos/farmacologia , Indóis/farmacologia , Moduladores de Tubulina/farmacologia , Tubulina (Proteína)/metabolismo , Antineoplásicos/síntese química , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Indóis/química , Estrutura Molecular , Polimerização/efeitos dos fármacos , Relação Estrutura-Atividade , Moduladores de Tubulina/síntese química , Moduladores de Tubulina/química , Células Tumorais Cultivadas
13.
Biochem J ; 475(5): 901-904, 2018 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-29511094

RESUMO

Two interesting papers by Barren et al. and Owen et al. have been very recently published in Biochemical Journal, reporting the role of translocator protein (TSPO) in steroidogenesis. The involvement of TSPO in the steroid biosynthesis has been suggested by 30 years of researches, using biochemical, pharmacological and genetic experimental approaches. In the last 3 years, however, the TSPO involvement in steroidogenesis has been intensively and profoundly discussed. Using in vivo genetic manipulations aimed at deleting TSPO, some researchers have excluded its role in steroid production. Other research groups, using similar genetic manipulation techniques, have presented different results, corroborating the role of TSPO in steroidogenesis, in particular, when hormonal stimulation occurs. In this scenario, the publications by Barron et al. about 'Steroidogenic abnormalities in translocator protein knockout mice and significance in the aging male' and by Owen et al. about 'TSPO mutations in rats and a human polymorphism impair the rate of steroid synthesis' are part of this debate and provide further and more accurate information supporting the importance of TSPO as a steroidogenesis regulator.


Assuntos
Receptores de GABA , Esteroides , Animais , Proteínas de Transporte , Humanos , Masculino , Camundongos , Camundongos Knockout , Ratos , Receptores de GABA-A
14.
J Med Chem ; 60(18): 7897-7909, 2017 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-28858490

RESUMO

The quinazoline class was exploited to search for a new translocator protein (TSPO) fluorescent probe endowed with improved affinity and residence time (RT). Computational studies on an "in-house" collection of quinazoline derivatives, featuring highly steric demanding groups at the amide nitrogen, suggested that, despite their molecular extension, these ligands are still easily lodged in the TSPO binding site. Binding assays supported this hypothesis, highlighting a low nanomolar/subnanomolar affinity of these ligands, together with a higher RT of the representative compound 11 with respect to our previously reported indole-based fluorescent probe. Thanks to the amenability of the amide nitrogen atom to be substituted with bulky groups, we developed quinazoline-based imaging tools by fluorescently labeling the scaffold at this position. Probes with relevant TSPO affinity, favorable spectroscopic properties, and improved RT were identified. The results from fluorescence microscopy showed that these probes specifically labeled the TSPO at the mitochondrial level in the U343 cell line.


Assuntos
Corantes Fluorescentes/química , Quinazolinas/química , Receptores de GABA/análise , Linhagem Celular Tumoral , Humanos , Ligantes , Microscopia de Fluorescência , Mitocôndrias/química , Imagem Óptica
15.
ChemMedChem ; 12(16): 1275-1278, 2017 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-28467680

RESUMO

Targeting the biosynthetic pathway of neuroactive steroids with specific 18 kDa translocator protein (TSPO) ligands may be a viable therapeutic approach for a variety of neurodegenerative and neuropsychiatric diseases. However, the lack of correlation between binding affinity and in vitro steroidogenic efficacy has limited the identification of lead compounds by traditional affinity-based drug discovery strategies. Our recent research indicates that the key factor for robust steroidogenic TSPO ligand efficacy is not the binding affinity per se, but rather the time the compound spends in the target, namely its residence time (RT). The assessment of this kinetic parameter during the in vitro characterization of compounds appears mandatory in order to obtain structure-efficacy relationships suitable for the future development of novel molecules with promising pharmacological properties.


Assuntos
Amidas/metabolismo , Ligantes , Neurotransmissores/metabolismo , Receptores de GABA/metabolismo , Amidas/química , Área Sob a Curva , Sítios de Ligação , Humanos , Cinética , Neurotransmissores/química , Ligação Proteica , Curva ROC , Receptores de GABA/química , Relação Estrutura-Atividade , Termodinâmica
16.
Oxid Med Cell Longev ; 2017: 9536148, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28386313

RESUMO

In recent years, the health-promoting effects of the citrus flavanone naringenin have been examined. The results have provided evidence for the modulation of some key mechanisms involved in cellular damage by this compound. In particular, naringenin has been revealed to have protective properties such as an antioxidant effect in cardiometabolic disorders. Very recently, beneficial effects of naringenin have been demonstrated in old rats. Because aging has been demonstrated to be directly related to the occurrence of cardiac disorders, in the present study, the ability of naringenin to prevent cardiac cell senescence was investigated. For this purpose, a cellular model of senescent myocardial cells was set up and evaluated using colorimetric, fluorimetric, and immunometric techniques. Relevant cellular senescence markers, such as X-gal staining, cell cycle regulator levels, and the percentage of cell cycle-arrested cells, were found to be reduced in the presence of naringenin. In addition, cardiac markers of aging-induced damage, including radical oxidative species levels, mitochondrial metabolic activity, mitochondrial calcium buffer capacity, and estrogenic signaling functions, were also modulated by the compound. These results suggested that naringenin has antiaging effects on myocardial cells.


Assuntos
Citrus/química , Flavanonas/farmacologia , Miócitos Cardíacos/efeitos dos fármacos , Envelhecimento/efeitos dos fármacos , Animais , Antioxidantes/química , Antioxidantes/farmacologia , Senescência Celular/efeitos dos fármacos , Flavanonas/química , Estresse Oxidativo/efeitos dos fármacos , Ratos , Espécies Reativas de Oxigênio/metabolismo
17.
ACS Chem Neurosci ; 8(7): 1448-1454, 2017 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-28362078

RESUMO

The low binding affinity of the approved anxiolytic drug etifoxine (Stresam) at the steroidogenic 18 kDa translocator protein (TSPO) has questioned the specific contribution of this protein in mediating the etifoxine neurosteroidogenic efficacy. Residence time (RT) at the binding site of the classical TSPO ligand PK11195 is emerging as a relevant neurosteroidogenic efficacy measure rather than the binding affinity. Here etifoxine was evaluated for (i) the in vitro neurosteroidogenic activity in comparison to poorly neurosteroidogenic reference TSPO ligands (PK11195 and Ro5-4864) and (ii) the affinity and RT at [3H]PK11195 and [3H]Ro5-4864 binding sites in rat kidney membranes. Etifoxine shows (i) high neurosteroidogenic efficacy and (ii) low affinity/short RT at the [3H]PK11195 site and low affinity/long RT at the [3H]Ro5-4864 site, at which etifoxine competitively bound. These findings suggest that the long RT of etifoxine at the Ro5-4864 binding site could account for its high neurosteroidogenic efficacy.


Assuntos
Ansiolíticos/metabolismo , Ansiolíticos/farmacologia , Benzodiazepinonas/metabolismo , Proteínas de Transporte/metabolismo , Neurotransmissores/metabolismo , Oxazinas/metabolismo , Receptores de GABA-A/metabolismo , Animais , Benzodiazepinonas/farmacologia , Sítios de Ligação , Ligação Competitiva , Linhagem Celular Tumoral , Flumazenil/farmacologia , Moduladores GABAérgicos/farmacologia , Hipolipemiantes/farmacologia , Isoquinolinas/farmacologia , Rim/efeitos dos fármacos , Rim/metabolismo , Cinética , Oxazinas/farmacocinética , Oxazinas/farmacologia , Pregnenolona/metabolismo , Ensaio Radioligante , Ratos , Termodinâmica , Trítio
18.
ACS Med Chem Lett ; 8(3): 293-298, 2017 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-28337319

RESUMO

Protein homodimers play important roles in physiological and pathological processes, including cancer invasion and metastasis. Recently, MMP-9 natural homodimerization via the PEX domain has been correlated with high migration rates of aggressive cancer cells. Here we propose that bifunctional MMP-9 inhibitors designed to impair natural MMP-9 homodimerization promoted by PEX-PEX interactions might be an effective tool to fight cancer cell invasion. Elaborating a previously described dimeric hydroxamate inhibitor 1, new ligands were synthesized with different linker lengths and branch points. Evaluation of the modified bifunctional ligands by X-ray crystallography and biological assays showed that 7 and 8 could reduce invasion in three glioma cell lines expressing MMP-9 at different levels. To rationalize these results, we present a theoretical model of full-length MMP-9 in complex with 7. This pioneering study suggests that a new approach using MMP-9 selective bifunctional inhibitors might lead to an effective therapy to reduce cancer cell invasion.

19.
Front Pharmacol ; 8: 71, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28289383

RESUMO

Background and Purpose: Incidence of cardiovascular disorders increases with age, because of a dramatic fall of endogenous self-defense mechanisms and increased vulnerability of myocardium. Conversely, the effectiveness of many cardioprotective drugs is blunted in hearts of 1 year old rat. The Citrus flavanone naringenin (NAR) was reported to promote cardioprotective effects against ischemia/reperfusion (I/R) injury, through the activation of mitochondrial large conductance calcium-activated potassium channel (mitoBK). These effects were observed in young adult rats, but no data are available about the possible cardioprotective effects of NAR in aged animals. Experimental Approach: This study aimed at evaluating the potential cardioprotective effects of NAR against I/R damage in 1 year old rats, and the possible involvement of mitoBK. Key Results: Naringenin protected the hearts of 1 year old rats in both ex vivo and in vivo I/R protocols. Noteworthy, these effects were antagonized by paxilline, a selective BK-blocker. The cardioprotective effects of NAR were also observed in senescent H9c2 cardiomyoblasts. In isolated mitochondria from hearts of 1 year old, NAR exhibited the typical profile of a mitoBK opener. Finally, Western Blot analysis confirmed a significant (albeit reduced) presence of BK-forming alpha and beta subunits, both in cardiac tissue of 1 year old rats and in senescent H9c2 cells. Conclusion and Implications: This is the first work reporting cardioprotective effects of NAR in 1 year old rats. Although further studies are needed to better understand the whole pathway involved in the NAR-mediated cardioprotection, these preliminary data represent a promising perspective for a rational nutraceutical use of NAR in aging.

20.
ACS Chem Neurosci ; 7(8): 1041-6, 2016 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-27385308

RESUMO

Recent data have demonstrated a positive correlation between the residence time (RT) and neurosteroidogenic efficacy of a ligand at the translocator protein (TSPO), an attractive anxyolitic target. To explore the potential impact of RT on TSPO ligand anxiolytic activity, the RT and the steroidogenic activity of XBD173, a ligand exerting anxiolytic activity in humans, were retrospectively evaluated. To this aim, XBD173 association and dissociation rate constants were measured (1.23 × 10(7) M(-1) min(-1) and 0.0079 min(-1), respectively). XBD173 resulted to have a long RT (127 min) and to stimulate efficaciously neurosteroidogenesis, in terms of pregnenolone production. The present findings corroborate the importance of TSPO ligand RT to predict their effective neurosteroidogenic activity and promising anxiolytic action. These positive results prompted us to set up a fast and high-throughput kinetic method to improve the efficiency of RT-based TSPO drug-discovery process.


Assuntos
Ansiolíticos/farmacologia , Pregnenolona/metabolismo , Purinas/farmacologia , Glândulas Suprarrenais/citologia , Animais , Antineoplásicos/farmacologia , Proteínas de Transporte , Linhagem Celular Tumoral , Membrana Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Glioma/patologia , Isoquinolinas/farmacocinética , Rim/citologia , Ligantes , Ligação Proteica/efeitos dos fármacos , Ratos , Receptores de GABA-A , Fatores de Tempo , Trítio/farmacocinética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...