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1.
Anticancer Res ; 40(5): 2613-2625, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32366406

RESUMO

BACKGROUND/AIM: The occurrence of BRAFV600E mutation causes an up-regulation of the B-raf kinase activity leading to the stabilization of hypoxia-inducible factor 1-alpha (HIF-1α) - the promoter of the 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) enzyme. The aim of the study was to examine the effect of the (2E)-3-(3-Pyridinyl)-1-(4-pyridinyl)-2-propen-1-one (3PO), as an inhibitor of PFKFB3, on human melanoma cells (A375) with endogenous BRAFV600E mutation. MATERIALS AND METHODS: A375 cells were exposed to different concentrations of 3PO and the following tests were performed: docking, cytotoxicity assay, immunocytochemistry staining glucose uptake, clonogenic assay, holotomography imaging, and flow cytometry. RESULTS: Our studies revealed that 3PO presents a dose-dependent and time-independent cytotoxic effect and promotes apoptosis of A375 cells. Furthermore, the obtained data indicate that 3PO induces cell cycle arrest in G1/0 and glucose uptake reduction. CONCLUSION: Taking all together, our research demonstrated a here should be proapoptotic and antiproliferative effect of 3PO on A375 human melanoma cells.


Assuntos
Inibidores Enzimáticos/farmacologia , Melanoma/enzimologia , Fosfofrutoquinase-2/antagonistas & inibidores , Piridinas/farmacologia , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Caspase 8/metabolismo , Domínio Catalítico , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Inibidores Enzimáticos/química , Glucose/metabolismo , Humanos , Melanoma/patologia , Simulação de Acoplamento Molecular , Terapia de Alvo Molecular , Fosfofrutoquinase-2/metabolismo , Piridinas/química , Ensaio Tumoral de Célula-Tronco
2.
Biochemistry ; 59(18): 1769-1779, 2020 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-32293875

RESUMO

Since the emergence of a novel coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first reported from Wuhan, China, neither a specific vaccine nor an antiviral drug against SARS-CoV-2 has become available. However, a combination of two HIV-1 protease inhibitors, lopinavir and ritonavir, has been found to be effective against SARS-CoV, and both drugs could bind well to the SARS-CoV 3C-like protease (SARS-CoV 3CLpro). In this work, molecular complexation between each inhibitor and SARS-CoV-2 3CLpro was studied using all-atom molecular dynamics simulations, free energy calculations, and pair interaction energy analyses based on MM/PB(GB)SA and FMO-MP2/PCM/6-31G* methods. Both anti-HIV drugs interacted well with the residues at the active site of SARS-CoV-2 3CLpro. Ritonavir showed a somewhat higher number atomic contacts, a somewhat higher binding efficiency, and a somewhat higher number of key binding residues compared to lopinavir, which correspond with the slightly lower water accessibility at the 3CLpro active site. In addition, only ritonavir could interact with the oxyanion hole residues N142 and G143 via the formation of two hydrogen bonds. The interactions in terms of electrostatics, dispersion, and charge transfer played an important role in the drug binding. The obtained results demonstrated how repurposed anti-HIV drugs could be used to combat COVID-19.


Assuntos
Antivirais/farmacologia , Infecções por Coronavirus/tratamento farmacológico , Inibidores Enzimáticos/farmacologia , Lopinavir/química , Lopinavir/farmacologia , Pneumonia Viral/tratamento farmacológico , Ritonavir/química , Ritonavir/farmacologia , Antivirais/uso terapêutico , Betacoronavirus/efeitos dos fármacos , Betacoronavirus/enzimologia , Domínio Catalítico , Infecções por Coronavirus/enzimologia , Infecções por Coronavirus/virologia , Cisteína Endopeptidases/química , Cisteína Endopeptidases/metabolismo , Reposicionamento de Medicamentos , Inibidores Enzimáticos/uso terapêutico , Humanos , Lopinavir/uso terapêutico , Simulação de Dinâmica Molecular , Pandemias , Pneumonia Viral/enzimologia , Pneumonia Viral/virologia , Ligação Proteica , Estrutura Terciária de Proteína , Ritonavir/uso terapêutico , Proteínas não Estruturais Virais/química , Proteínas não Estruturais Virais/metabolismo
3.
Life Sci ; 250: 117602, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32240677

RESUMO

AIMS: Extrinsic ageing or photoageing relates to the onset of age-linked phenotypes such as skin hyperpigmentation due to UV exposure. UV induced upregulated production of tyrosinase enzyme, which catalyses the vital biochemical reactions of melanin synthesis is responsible for the inception of skin hyperpigmentation. We aimed to generate a validated QSAR model with a dataset consisting of 69 thio-semicarbazone derivatives to elucidate the physicochemical properties of compounds essential for tyrosinase inhibition and to identify novel lead molecules with enhanced tyrosinase inhibitory activity and bioavailability. MAIN METHODS: Lead optimization and insilico approaches were employed in this research work. QSAR model was generated and validated by exploiting Multiple Linear Regression method. Prioritization of lead-like compounds was accomplished by performing multi parameter optimization depleting molecular docking, bioavailability assessments and toxicity prediction for 69 compounds Derivatives of best lead compound were retrieved from chemical spaces. KEY FINDINGS: Molecular descriptors explicated the significance of chemical properties essential for chelation of copper ions present in the active site of tyrosinase protein target. Further, derivatives which comprise of electron donating groups in their chemical structure were predicted and analysed for tyrosinase inhibitory activity by employing insilico methodologies including chemical space exploration. SIGNIFICANCE: Our research work resulted in the generation of a validated QSAR model with higher degree of external predictive ability and significance to tyrosinase inhibitory activity. We propose 11 novel derivative compounds with enhanced tyrosinase inhibitory activity and bioavailability.


Assuntos
Química Farmacêutica/métodos , Biologia Computacional/métodos , Indóis/antagonistas & inibidores , Monofenol Mono-Oxigenase/antagonistas & inibidores , Pele/efeitos dos fármacos , Agaricales/metabolismo , Domínio Catalítico , Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos , Elétrons , Inibidores Enzimáticos/farmacologia , Humanos , Ligação de Hidrogênio , Ligantes , Simulação de Acoplamento Molecular , Estrutura Molecular , Monofenol Mono-Oxigenase/metabolismo , Relação Quantitativa Estrutura-Atividade , Pigmentação da Pele/efeitos dos fármacos , Tiossemicarbazonas/química , Raios Ultravioleta
4.
Mutat Res ; 852: 503169, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32265043

RESUMO

The phycotoxins, okadaic acid (OA) and dinophysistoxins 1 and 2 (DTX-1 and -2), are protein phosphatase PP2A and PP1 inhibitors involved in diarrhetic shellfish poisoning (DSP) in humans. Data on the in vivo acute toxicity of the OA-group toxins show some differences and the European Food Safety Authority (EFSA) has determined toxicity equivalent factors (TEFs) of one for the reference toxin, OA, as well as for DTX-1 and 0.6 for DTX-2. However, recent in vitro studies indicated that DTX-1 seems to be more toxic than OA. As OA was described as apoptotic and aneugenic compound, we analyzed the DNA damage responses induced by the 3 toxins through γH2AX and pH3 biomarkers on proliferative HepaRG cells using High Content Analysis. We quantitatively examined the responses for γH2AX and pH3 by benchmark dose analyzing (BMD) using PROAST software. We found that the three toxins increased both γH2AX- and pH3-positive cells populations in a concentration-dependent manner. The 3 toxins induced mitotic arrest, characteristic of aneugenic compounds, as well as DNA strand-breaks concomitantly to cytotoxicity. BMD analysis showed that DTX-1 is the most potent inducer of DNA damage, followed by OA and DTX-2. The quantitative genotoxic data provided in this study are additional findings for reconsidering the estimated TEFs of this group of phycotoxins.


Assuntos
Inibidores Enzimáticos/toxicidade , Histonas/genética , Mutagênicos/toxicidade , Ácido Okadáico/toxicidade , Piranos/toxicidade , Benchmarking , Biomarcadores/metabolismo , Linhagem Celular Transformada , Proliferação de Células/efeitos dos fármacos , Dano ao DNA , Relação Dose-Resposta a Droga , Hepatócitos/citologia , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Histonas/metabolismo , Humanos , Interações Hidrofóbicas e Hidrofílicas , Mitose/efeitos dos fármacos , Testes de Mutagenicidade , Fosforilação/efeitos dos fármacos , Software
5.
Hum Genet ; 139(5): 657-673, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32219518

RESUMO

GM1-gangliosidosis, a lysosomal storage disorder, is associated with ~ 161 missense variants in the GLB1 gene. Affected patients present with ß-galactosidase (ß-Gal) deficiency in lysosomes. Loss of function in ER-retained misfolded enzymes with missense variants is often due to subcellular mislocalization. Deoxygalactonojirimycin (DGJ) and its derivatives are pharmaceutical chaperones that directly bind to mutated ß-Gal in the ER promoting its folding and trafficking to lysosomes and thus enhancing its activity. An Emirati child has been diagnosed with infantile GM1-gangliosidosis carrying the reported p.D151Y variant. We show that p.D151Y ß-Gal in patient's fibroblasts retained < 1% residual activity due to impaired processing and trafficking. The amino acid substitution significantly affected the enzyme conformation; however, p.D151Y ß-Gal was amenable for partial rescue in the presence of glycerol or at reduced temperature where activity was enhanced with ~ 2.3 and 7 folds, respectively. The butyl (NB-DGJ) and nonyl (NN-DGJ) derivatives of DGJ chaperoning function were evaluated by measuring their IC50s and ability to stabilize the wild-type ß-Gal against thermal degradation. Although NN-DGJ showed higher affinity to ß-Gal, it did not show a significant enhancement in p.D151Y ß-Gal activity. However, NB-DGJ promoted p.D151Y ß-Gal maturation and enhanced its activity up to ~ 4.5% of control activity within 24 h which was significantly increased to ~ 10% within 6 days. NB-DGJ enhancement effect was sustained over 3 days after washing it out from culture media. We therefore conclude that NB-DGJ might be a promising therapeutic chemical chaperone in infantile GM1 amenable variants and therefore warrants further analysis for its clinical applications.


Assuntos
1-Desoxinojirimicina/farmacologia , Fibroblastos/metabolismo , Gangliosidose GM1/metabolismo , Proteínas Mutantes/metabolismo , Mutação , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , beta-Galactosidase/metabolismo , 1-Desoxinojirimicina/química , Pré-Escolar , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/patologia , Gangliosidose GM1/tratamento farmacológico , Gangliosidose GM1/patologia , Humanos , Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , Lisossomos/patologia , Masculino , Chaperonas Moleculares/farmacologia , Proteínas Mutantes/química , Proteínas Mutantes/genética , Conformação Proteica , Transporte Proteico , beta-Galactosidase/química , beta-Galactosidase/genética
6.
Braz J Med Biol Res ; 53(3): e8853, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32130289

RESUMO

Anaphylactic shock can be defined as an acute syndrome, and it is the most severe clinical manifestation of allergic diseases. Anaphylactoid reactions are similar to anaphylactic events but differ in the pathophysiological mechanism. Nitric oxide (NO) inhibitors during anaphylaxis suggest that NO might decrease the signs and symptoms of anaphylaxis but exacerbate associated vasodilation. Therefore, blocking the effects of NO on vascular smooth muscle by inhibiting the guanylate cyclase (GC) would be a reasonable strategy. This study aimed to investigate the effects of NO/cGMP pathway inhibitors methylene blue (MB), Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME), and indigo carmine (IC) in shock induced by compound 48/80 (C48/80) in rats. The effect was assessed by invasive blood pressure measurement. Shock was initiated by C48/80 intravenous bolus injection 5 min before (prophylactic) or after (treatment) the administration of the inhibitors MB (3 mg/kg), L-NAME (1 mg/kg), and IC (3 mg/kg). Of the groups that received drugs as prophylaxis for shock, only the IC group did not present the final systolic blood pressure (SBP) better than the C48/80 group. Regarding shock treatment with the drugs tested, all groups had the final SBP similar to the C48/80group. Altogether, our results suggested that inhibition of GC and NO synthase in NO production pathway was not sufficient to revert hypotension or significantly improve survival.


Assuntos
Anafilaxia/tratamento farmacológico , GMP Cíclico/antagonistas & inibidores , Inibidores Enzimáticos/administração & dosagem , Músculo Liso Vascular/efeitos dos fármacos , Óxido Nítrico/antagonistas & inibidores , Animais , Modelos Animais de Doenças , Índigo Carmim/administração & dosagem , Masculino , Azul de Metileno/administração & dosagem , NG-Nitroarginina Metil Éster/administração & dosagem , Ratos , Ratos Wistar
7.
Mol Genet Genomics ; 295(3): 695-703, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32124033

RESUMO

Fission yeast Cds1 is responsible for the replication checkpoint activation and helps to protect replication fork collapse in response to hydroxyurea (HU). Here, we investigated the role of histone deacetylase in response to replication fork arrest and observed that in the presence of HU, the survival of cds1Δ cells was improved when the cells were simultaneously treated with histone deacetylase inhibitors. Furthermore, a mutation in the histone deacetylase gene, clr6, also suppresses the growth defect of cds1Δ cells in response to HU indicating a suppressive role of clr6-1 mutation in cds1 deletion background upon HU treatment. Interestingly, in response to HU, phosphorylation of Chk1 kinase and the number of Rad52YFP foci was reduced in cds1Δ clr6-1 double mutant as compared to cds1Δ single mutant indicating a decrease in the level of DNA damage in response to HU. Accordingly, the single-cell gel electrophoresis assay revealed a drastic reduction in the tail length of cds1Δ clr6-1 double mutant as compared to cds1Δ cells in the presence of HU suggesting the suppression of chromosomal defects in the double mutant. Taken together, we proposed that there could be transient suppression of fork collapse in cds1Δ clr6-1 double mutant upon HU treatment due to the delay in mitotic progression that leads to the facilitation of cell growth.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Quinase do Ponto de Checagem 2/genética , Quinase do Ponto de Checagem 2/metabolismo , Hidroxiureia/farmacologia , Mutação , Proteínas de Schizosaccharomyces pombe/genética , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/crescimento & desenvolvimento , Proteínas de Ciclo Celular/antagonistas & inibidores , Proteínas de Ciclo Celular/genética , Inibidores Enzimáticos/farmacologia , Inibidores de Histona Desacetilases/farmacologia , Ácidos Hidroxâmicos/farmacologia , Fosforilação , Schizosaccharomyces/efeitos dos fármacos , Schizosaccharomyces/genética , Proteínas de Schizosaccharomyces pombe/antagonistas & inibidores
8.
DNA Cell Biol ; 39(5): 733-737, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32181687

RESUMO

Ceramides have emerged as important regulators of tissue metabolism that play essential roles in cardiometabolic disease. They are potent biomarkers of diabetes and heart disease and are now being measured clinically as predictors of major adverse cardiac events. Moreover, studies in rodents reveal that inhibitors of ceramide synthesis prevent or reverse the pathogenic features of type 2 diabetes, nonalcoholic fatty liver disease, atherosclerosis, and cardiomyopathy. Herein the authors discuss inhibition of dihydroceramide desaturase-1, the final enzyme in the ceramide biosynthesis pathway, as a potential therapeutic approach to lower ceramides and combat cardiometabolic disease.


Assuntos
Metabolismo dos Lipídeos , Doenças Metabólicas/metabolismo , Oxirredutases/metabolismo , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Doenças Metabólicas/tratamento farmacológico , Doenças Metabólicas/enzimologia , Oxirredutases/antagonistas & inibidores
9.
Chem Biol Interact ; 322: 109053, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32198085

RESUMO

Notopterol (NOT) is a major bioactive ingredient extracted from the rhizomes of either Notopterygium incisum Ting ex H. T. Chang or N. forbesii Boiss (Qianghuo in Chinese), a botanical drug that was adopted as a traditional Chinese medicine. NOT is suggested to show analgesic and anti-inflammatory effects in clinical practice. The inhibitory effects of NOT on human cytochrome P450 enzymes were investigated in the present study. Our results indicate that NOT inhibited the activity of CYP2D6 in a time-, concentration- and NADPH-dependent manner. The values of KI and kinact were 10.8 µM and 0.62 min-1, respectively. The calculated kobs at 10 µM was 0.29 min-1, above the 0.02 min-1 risk level. After incubation with NOT at 10 µM for 9 min, approximately 92% of CYP2D6 activity was inhibited. Such loss of enzyme activity was not restored through dialysis, which indicates that the observed enzyme inhibition was irreversible. Partition ratio of the inactivation was approximately 29. Quinidine, a competitive CYP2D6 inhibitor, demonstrated protection on enzymes against the NOT-induced inactivation, but such protection was not found in incubation systems fortified with glutathione or catalase/superoxide dismutase. Additionally, CYP3A4 was observed to function as an enzyme mainly involved in the biotransformation of NOT. Taken together, these findings indicate that NOT served as a mechanism-based inactivator of CYP2D6, meanwhile, those observed effects may induce the latent drug-drug interactions. The metabolic activation of NOT may be the key to trigger the inactivation of the enzyme.


Assuntos
Cumarínicos/metabolismo , Citocromo P-450 CYP2D6/metabolismo , Ativação Metabólica , Apiaceae/química , Apiaceae/metabolismo , Cumarínicos/química , Citocromo P-450 CYP2D6/química , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Glutationa/antagonistas & inibidores , Glutationa/metabolismo , Humanos , Cinética , NADP/química , NADP/metabolismo , Superóxido Dismutase/antagonistas & inibidores , Superóxido Dismutase/metabolismo
10.
Lancet Haematol ; 7(4): e309-e319, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32145771

RESUMO

BACKGROUND: Mutations in isocitrate dehydrogenase-2 (IDH2) occur in around 5% of patients with myelodysplastic syndromes. Neomorphic activity of mutant IDH2 proteins results in hypermethylation of DNA and histones, leading to blocked haemopoietic differentiation. Enasidenib, an inhibitor of mutated IDH2 proteins, induces responses in patients with IDH2-mutated, relapsed or refractory acute myeloid leukaemia. We aimed to establish the clinical outcomes of enasidenib monotherapy in a subgroup of patients with myelodysplastic syndromes harbouring mutations in IDH2 from the AG221-C-001 trial. METHODS: The multicentre, open-label, phase 1-2 AG221-C-001 trial enrolled patients with advanced haematological malignancies (2008 WHO criteria) harbouring an IDH2 mutation. The present study is a subgroup analysis of patients with IDH2-mutated myelodysplastic syndromes in the phase 1 dose-escalation and expansion portions of the trial. Patients with myelodysplastic syndromes were aged 18 years or older with an ECOG performance status score of 2 or lower, and were relapsed or refractory to, or ineligible for, standard treatments. Patients received oral doses of enasidenib at 60-300 mg per day in repeated 28-day treatment cycles. In this subgroup analysis, we focused on the safety and activity of enasidenib as main outcomes. Overall response rate, duration of response, and overall and event-free survival analyses were by intention-to-treat. Safety was assessed in all participants who received at least one dose of study drug in terms of treatment-emergent adverse events. The AG221-C-001 trial is registered on ClinicalTrials.gov, NCT01915498, status ongoing but closed to recruitment. FINDINGS: 17 patients with myelodysplastic syndromes harbouring an IDH2 mutation (median age, 67·0 years [IQR 60·5-73·0]) were enrolled between Feb 18, 2014, and Sept 1, 2015. At data cutoff (Oct 1, 2018), after a median follow-up of 11·0 months (IQR 6·8-23·0), all patients had discontinued enasidenib, with a median of 3 treatment cycles (2-15) for all patients (five [29%] received ≥12 cycles). At entry, three (18%) patients had relapsed after allogeneic stem-cell transplants, 13 (76%) had previously received therapy with hypomethylating agents, and ten (59%) had received at least two previous therapies. No dose-limiting toxicities were reported. The most common treatment-emergent adverse events were diarrhoea and nausea (in nine [53%] patients each). Most common grade 3-4 treatment-emergent adverse events were indirect hyperbilirubinaemia (in six [35%] patients), pneumonia (in five [29%] patients), and thrombocytopaenia (in four [24%] patients). Serious treatment-emergent adverse events in more than one patient were pneumonia (in five [29% patients); tumor lysis syndrome (in three [18%] patients); and sepsis, atrial flutter, indirect hyperbilirubinaemia, cerebral hemorrhage, and mental status change (in two [12%] patients each). No treatment-related deaths occurred. An overall response was achieved in 9 patients (53% [95% CI 28-77]), with a median duration of response of 9·2 months (95% CI 1·0-not reached). Six (46%) of 13 patients previously treated with hypomethylating agents responded. Median overall survival was 16·9 months (95% CI 1·5-32·3), and median event-free survival was 11·0 months (1·5-16·7). INTERPRETATION: Enasidenib is generally well tolerated and can induce responses in patients with mutant IDH2 myelodysplastic syndromes, including in those who have had previous therapy with hypomethylating agents. Testing for IDH2 mutations in myelodysplastic syndromes is essential for identifying patients who might benefit from enasidenib therapy, including those patients in whom conventional treatments have been unsuccessful. FUNDING: Celgene and Agios Pharmaceuticals.


Assuntos
Aminopiridinas/uso terapêutico , Inibidores Enzimáticos/uso terapêutico , Isocitrato Desidrogenase/genética , Síndromes Mielodisplásicas/tratamento farmacológico , Triazinas/uso terapêutico , Idoso , Aminopiridinas/efeitos adversos , Intervalo Livre de Doença , Relação Dose-Resposta a Droga , Esquema de Medicação , Inibidores Enzimáticos/efeitos adversos , Feminino , Humanos , Hiperbilirrubinemia/etiologia , Masculino , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/mortalidade , Polimorfismo de Nucleotídeo Único , Taxa de Sobrevida , Resultado do Tratamento , Triazinas/efeitos adversos
11.
Braz J Med Biol Res ; 53(3): e8761, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32159612

RESUMO

Nitric oxide (NO) inhibition by high-dose NG-nitro-L-arginine methyl ester (L-NAME) is associated with several detrimental effects on the cardiovascular system. However, low-dose L-NAME increases NO synthesis, which in turn induces physiological cardiovascular benefits, probably by activating a protective negative feedback mechanism. Aerobic exercise, likewise, improves several cardiovascular functions in healthy hearts, but its effects are not known when chronically associated with low-dose L-NAME. Thus, we tested whether the association between low-dose L-NAME administration and chronic aerobic exercise promotes beneficial effects to the cardiovascular system, evaluating the cardiac remodeling process. Male Wistar rats were randomly assigned to control (C), L-NAME (L), chronic aerobic exercise (Ex), and chronic aerobic exercise associated to L-NAME (ExL). Aerobic training was performed with progressive intensity for 12 weeks; L-NAME (1.5 mg·kg-1·day-1) was administered by orogastric gavage. Low-dose L-NAME alone did not change systolic blood pressure (SBP), but ExL significantly increased SBP at week 8 with normalization after 12 weeks. Furthermore, ExL promoted the elevation of left ventricle (LV) end-diastolic pressure without the presence of cardiac hypertrophy and fibrosis. Time to 50% shortening and relaxation were reduced in ExL, suggesting a cardiomyocyte contractile improvement. In addition, the time to 50% Ca2+ peak was increased without alterations in Ca2+ amplitude and time to 50% Ca2+ decay. In conclusion, the association of chronic aerobic exercise and low-dose L-NAME prevented cardiac pathological remodeling and induced cardiomyocyte contractile function improvement; however, it did not alter myocyte affinity and sensitivity to intracellular Ca2+ handling.


Assuntos
Cálcio/análise , Inibidores Enzimáticos/farmacologia , Contração Miocárdica/efeitos dos fármacos , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico Sintase/efeitos dos fármacos , Condicionamento Físico Animal/fisiologia , Adiposidade , Animais , Peso Corporal/fisiologia , Inibidores Enzimáticos/administração & dosagem , Hemodinâmica , Masculino , Modelos Animais , Atividade Motora/fisiologia , Miocárdio/patologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/fisiologia , NG-Nitroarginina Metil Éster/administração & dosagem , Óxido Nítrico Sintase/metabolismo , Ratos Wistar , Pressão Ventricular/efeitos dos fármacos
12.
Public Health Res Pract ; 30(1)2020 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-32152617

RESUMO

BACKGROUND: Influenza attack rates in closed population settings, such as residential aged care facilities (RACFs), can be more than 50% during annual epidemics. Uncertainty about the effectiveness of neuraminidase inhibitors (NAIs) as prophylaxis for influenza outbreaks has led to variations in their use in RACFs in New South Wales (NSW), Australia. OBJECTIVES: To examine the use of prophylactic NAIs by NSW RACFs for residents during influenza outbreaks in the 2015 influenza season. METHODS: A prospective cohort study of influenza outbreaks reported to NSW Public Health Units from 1 June 2015 - 31 October 2015. RESULTS: Eighty-eight RACFs reported influenza outbreaks; 86 were included in the study. Fifty-two RACFs used prophylactic NAIs; 34 did not. The median time to start NAI prophylaxis from the onset date of the first case was 8.5 days (range 2-23). The average proportion of residents within a facility that received prophylaxis was 51%percnt; (range 0.7-95). CONCLUSION: Variations in the use of prophylactic NAIs exist across RACFs. Earlier initiation of NAI prophylaxis, improved resident coverage where appropriate and other practice changes are recommended for the management of influenza outbreaks in RACFs.


Assuntos
Surtos de Doenças/prevenção & controle , Inibidores Enzimáticos , Influenza Humana/prevenção & controle , Neuraminidase , Idoso , Idoso de 80 Anos ou mais , Antivirais/uso terapêutico , Inibidores Enzimáticos/uso terapêutico , Feminino , Humanos , Vírus da Influenza A , Vírus da Influenza B , Masculino , Neuraminidase/antagonistas & inibidores , New South Wales , Estudos Prospectivos
13.
Invest Ophthalmol Vis Sci ; 61(2): 7, 2020 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-32031579

RESUMO

Purpose: Confirm that the corneal endothelial pump uses a lactate-coupled water efflux mechanism. Methods: Corneal thickness, lactate efflux, and stromal [lactate] were measured in de-epithelialized swollen and nonswollen ex vivo-mounted rabbit corneas perfused with bicarbonate-rich and bicarbonate-free Ringers, ouabain, or acetazolamide to determine if the relationships among these parameters were similar to previous data using intact corneas. The role of barrier function was tested by perfusion with calcium-free EGTA. Predictions of [lactate] in endothelial dystrophy were examined in the Slc4a11 knock out mouse. Results: De-epithelialized corneal swelling, lactate efflux, and stromal [lactate] in response to bicarbonate-free Ringers, ouabain, and acetazolamide perfusion had the same relationship as in intact corneas. The absolute amount of lactate efflux and stromal [lactate] in the de-epithelialized corneas was about half of intact corneas. De-epithelialized, swollen corneas deswelled fully with bicarbonate-rich, partially in the presence of acetazolamide, but continued to swell with bicarbonate-free or ouabain. The relationship among corneal thickness, lactate efflux, and [lactate] was the same as with nonswollen de-epithelialized corneas. In intact corneas swollen by perfusion with calcium-free EGTA, the relationship between swelling and lactate flux was the inverse of control corneas. The relationship between corneal swelling and [lactate] of intact corneas exposed to ouabain, but perfused with 7 mM lactate to simulate aqueous humor, was the same as without lactate. Corneal [lactate] in Slc4a11 knock out was twice that of wild type. Conclusions: The corneal endothelial pump works via a lactate efflux mechanism that requires an intact osmotic barrier.


Assuntos
Epitélio Posterior/metabolismo , Ácido Láctico/metabolismo , Animais , Proteínas de Transporte de Ânions/metabolismo , Transporte Biológico Ativo/fisiologia , Córnea/metabolismo , Edema da Córnea/fisiopatologia , Inibidores Enzimáticos/farmacologia , Feminino , Masculino , Camundongos Knockout , Ouabaína/farmacologia , Coelhos , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores , Simportadores/metabolismo
14.
DNA Cell Biol ; 39(4): 572-578, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32073884

RESUMO

DNA methylation inhibitor or loss and gain of function of DNA methylation key players were widely used to investigate the regulation of X inactive-specific transcript (Xist) expression by DNA methylation, which results in global change of DNA methylation. Here, we reported a novel method for regulation of Xist using the widely used clustered regularly interspaced short palindromic repeat (CRISPR)-Cas system. First, Xist expression was increased in 5-aza-2'-deoxycytidine-treated female goat fibroblast cells. Second, three single-guide RNAs (sgRNAs) that target the Xist differential methylation region (DMR) were inserted to deactivated Cas9 (dCas9) nuclease and the catalytic domain of the DNA methyltransferase Dnmt3a coexpression plasmid. Bisulfite PCR analysis and quantitative real-time PCR revealed that the methylation level of the DMR was significantly increased, while the expression of Xist was downregulated in all three sgRNAs, compared with the mock-transfected cells. Third, the methylation activity at the sites of 37 bp from the protospacer-adjacent motif sequence showed the strong change relative to the mock-transfected cells. Furthermore, genome-wide DNA methylation and expression of the DNA methylation key players were not statistically changed in all three sgRNAs. Therefore, we confirmed that Xist expression was regulated by DNA methylation, and directed DNA methylation of Xist DMR at locus-specific solution decreased Xist expression.


Assuntos
Sistemas CRISPR-Cas/genética , DNA (Citosina-5-)-Metiltransferases/genética , Metilação de DNA/genética , Regulação da Expressão Gênica/genética , RNA Longo não Codificante/genética , Animais , Domínio Catalítico/genética , Linhagem Celular , DNA (Citosina-5-)-Metiltransferases/metabolismo , Decitabina/farmacologia , Inibidores Enzimáticos/farmacologia , Feminino , Fibroblastos , Cabras , RNA Guia/genética
15.
Nat Rev Rheumatol ; 16(3): 167-178, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32055040

RESUMO

The introduction of biologic DMARDs into rheumatology has resulted in a substantial reduction of the burden of many rheumatic diseases. In the slipstream of the success achieved with these biologic DMARDs, some conventional immunosuppressive drugs have also found use in new indications. Notably, mycophenolate mofetil, azathioprine and tacrolimus have made their way from solid organ transplantation drugs to become useful assets in rheumatology practice. Mycophenolate mofetil and azathioprine inhibit the purine pathway and subsequently diminish cell proliferation. Both drugs have a pivotal role in the treatment of various rheumatic diseases, including lupus nephritis. Tacrolimus inhibits lymphocyte activation by inhibiting the calcineurin pathway. Mycophenolate mofetil and tacrolimus are, among other indications, increasingly being recognized as useful drugs in the treatment of interstitial lung disease in systemic rheumatic diseases and skin fibrosis in systemic sclerosis. A broad array of trials with mycophenolate mofetil, azathioprine and/or tacrolimus are ongoing within the field of rheumatology that might provide further novel avenues for the use of these drugs. In this Review, we discuss the historical perspective, pharmacodynamics, clinical indications and novel avenues for mycophenolate mofetil, azathioprine and tacrolimus in rheumatology.


Assuntos
Azatioprina/uso terapêutico , Ácido Micofenólico/uso terapêutico , Doenças Reumáticas/tratamento farmacológico , Reumatologia , Tacrolimo/uso terapêutico , Antirreumáticos/farmacocinética , Antirreumáticos/uso terapêutico , Azatioprina/farmacocinética , Quimioterapia Combinada , Inibidores Enzimáticos/farmacocinética , Inibidores Enzimáticos/uso terapêutico , Humanos , Imunossupressores/farmacocinética , Imunossupressores/uso terapêutico , Ácido Micofenólico/farmacocinética , Tacrolimo/farmacocinética
16.
Metabolism ; 105: 154182, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32061660

RESUMO

The impairment of podocyte protein filtration function caused by excessive mitochondrial calcium intake is a critical feature of diabetic nephropathy (DN). Ca2+ channel transient receptor potential cation channel subfamily V member 1 (TRPV1) has been reported to protect against ischemia-reperfusion induced acute renal injury, but there is no report about its role in DN. Here, we report that dietary capsaicin potently inhibits and reverses chronic renal structural and functional damages in db/db or streptozotocin (STZ)-induced diabetic mice in a TRPV1-dependent manner. Activation of TRPV1 by capsaicin alleviated hyperglycemia-induced mitochondrial dysfunction in podocytes, accompanied by reduced mitochondria-associated membranes (MAMs) formation and fewer Ca2+ transport from endoplasmic reticulum (ER) to mitochondria. Mechanistically, TRPV1-mediated transient Ca2+ influx activated 5' AMP-activated protein kinase (AMPK) that reduced the transcription of Fundc1, a key molecule participating in MAMs formation. Inhibition of AMPK or overexpression of Fundc1 obviously blocked the inhibitory effect of capsaicin on MAMs formation and functional decline in podocytes. These findings emphasize the critical role of mitochondrial Ca2+ homeostasis in the maintenance of normal renal function and suggest an effective intervention method to counteract DN.


Assuntos
Nefropatias Diabéticas/tratamento farmacológico , Retículo Endoplasmático/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Podócitos/efeitos dos fármacos , Canais de Cátion TRPV/metabolismo , Proteínas Quinases Ativadas por AMP/antagonistas & inibidores , Proteínas Quinases Ativadas por AMP/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Canais de Cálcio/metabolismo , Capsaicina/uso terapêutico , Dieta , Inibidores Enzimáticos/farmacologia , Hiperglicemia/tratamento farmacológico , Hiperglicemia/microbiologia , Proteínas de Membrana/antagonistas & inibidores , Proteínas de Membrana/biossíntese , Camundongos , Camundongos Endogâmicos C57BL , Membranas Mitocondriais/efeitos dos fármacos , Proteínas Mitocondriais/antagonistas & inibidores , Proteínas Mitocondriais/biossíntese
17.
Ecotoxicol Environ Saf ; 192: 110305, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32070782

RESUMO

Environmental xenoestrogens are the most accessible endocrine disrupting chemicals that have been reported with harmful effects on human health. Although the influences of xenoestrogens on the endocrine system have been extensively studied, it remains unclear whether these xenoestrogens can affect the digestive system in mammals. This study aimed to investigate the inhibitory effects and the underlying mechanism of six non-steroidal synthetic estrogens (including hexestrol, diethylstilbestrol, dienestrol, bisphenol A, bisphenol AF and bisphenol Z) on pancreatic lipase (PL), a key digestive enzyme responsible for lipid digestion and absorption in mammals. The results clearly demonstrated that hexestrol, diethylstilbestrol and dienestrol exhibited strong inhibition on PL, with the IC50 values of less than 1.0 µM. Further investigations elucidated that these three synthetic estrogens functioned as mixed inhibitors of PL, with the Ki values of less than 1 µM. Moreover, molecular dynamics simulations showed that diethylstilbestrol and its analogues might block the binding of substrate on PL via occupying the portal to the active site of PL and thereby inhibit the hydrolytic activity of this key enzyme. Collectively, these results suggested that diethylstilbestrol and its analogues were potent PL inhibitors, which might play a profound role in lipid absorption and weight gain in mammals.


Assuntos
Disruptores Endócrinos/toxicidade , Poluentes Ambientais/toxicidade , Inibidores Enzimáticos/toxicidade , Lipase/antagonistas & inibidores , Pâncreas/enzimologia , Animais , Domínio Catalítico , Estrogênios não Esteroides/toxicidade , Humanos , Lipase/química , Lipase/metabolismo , Xenobióticos
18.
PLoS Negl Trop Dis ; 14(2): e0007983, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32106219

RESUMO

The development of chemotherapies against eukaryotic pathogens is especially challenging because of both the evolutionary conservation of drug targets between host and parasite, and the evolution of strain-dependent drug resistance. There is a strong need for new nontoxic drugs with broad-spectrum activity against trypanosome parasites such as Leishmania and Trypanosoma. A relatively untested approach is to target macromolecular interactions in parasites rather than small molecular interactions, under the hypothesis that the features specifying macromolecular interactions diverge more rapidly through coevolution. We computed tRNA Class-Informative Features in humans and independently in eight distinct clades of trypanosomes, identifying parasite-specific informative features, including base pairs and base mis-pairs, that are broadly conserved over approximately 250 million years of trypanosome evolution. Validating these observations, we demonstrated biochemically that tRNA:aminoacyl-tRNA synthetase (aaRS) interactions are a promising target for anti-trypanosomal drug discovery. From a marine natural products extract library, we identified several fractions with inhibitory activity toward Leishmania major alanyl-tRNA synthetase (AlaRS) but no activity against the human homolog. These marine natural products extracts showed cross-reactivity towards Trypanosoma cruzi AlaRS indicating the broad-spectrum potential of our network predictions. We also identified Leishmania major threonyl-tRNA synthetase (ThrRS) inhibitors from the same library. We discuss why chemotherapies targeting multiple aaRSs should be less prone to the evolution of resistance than monotherapeutic or synergistic combination chemotherapies targeting only one aaRS.


Assuntos
Alanina-tRNA Ligase/antagonistas & inibidores , Antiprotozoários/farmacologia , Inibidores Enzimáticos/farmacologia , Leishmania/enzimologia , Proteínas de Protozoários/antagonistas & inibidores , Treonina-tRNA Ligase/antagonistas & inibidores , Trypanosoma/efeitos dos fármacos , Alanina-tRNA Ligase/genética , Alanina-tRNA Ligase/metabolismo , Antiprotozoários/química , Inibidores Enzimáticos/química , Humanos , Leishmania/efeitos dos fármacos , Leishmania/genética , Leishmaniose/parasitologia , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Treonina-tRNA Ligase/genética , Treonina-tRNA Ligase/metabolismo , Trypanosoma/enzimologia , Trypanosoma/genética , Tripanossomíase/parasitologia
19.
Phys Chem Chem Phys ; 22(10): 5487-5499, 2020 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-32101223

RESUMO

Ubiquitin specific protease 7 (USP7) has attracted increasing attention because of its multifaceted roles in different tumor types. The crystal structures of USP7-inhibitor complexes resolved recently provide reliable models for computational structure-based drug design (SBDD) towards USP7. How to accurately estimate USP7-ligand binding affinity is quite critical to guarantee the reliability of SBDD. In this study, we assessed the reliability of multiple computational methods to the binding affinity prediction for a series of USP7 inhibitors with the pyrimidinone scaffold, including molecular docking scoring, MM/PB(GB)SA, and umbrella sampling (US). It was found that the accuracy of the evaluated computational methods for binding affinity prediction follows the order: US-based method > MM/PB(GB)SA > Glide XP scoring. The calculation results demonstrate that incorporating protein flexibility through induced-fit docking or ensemble docking cannot improve the performance of the Glide scoring based on rigid-receptor docking. For the MM/PB(GB)SA methods, the choice of the protein structure and the calculation procedure has a marked impact on the predictions. More importantly, we discovered for the first time that there are significant differences in the dissociation pathways of strong-binding inhibitors and weak-binding inhibitors of USP7, which may be used as a new criterion to judge whether an inhibitor is a strong binder or not. It is expected that our work can provide valuable guidance on the design and discovery of potent USP7 inhibitors.


Assuntos
Química Computacional , Inibidores Enzimáticos/metabolismo , Pirimidinonas/química , Peptidase 7 Específica de Ubiquitina/metabolismo , Desenho de Fármacos , Inibidores Enzimáticos/química , Ligação Proteica
20.
Drugs Today (Barc) ; 56(1): 21-32, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32055803

RESUMO

Isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) are key metabolic enzymes that convert isocitrate to alpha-ketoglutarate (alphaKG). Somatic point mutations in IDH1/2 that are found in rare distinct subsets of cancers confer a gain of function in cancer cells which results in the accumulation and secretion in vast excess of the oncometabolite D-2-hydroxyglutarate (D-2HG). Overproduction of D-2HG interferes with cellular metabolism and epigenetic regulation, contributing to oncogenesis. High levels of D-2HG inhibit alphaKG-dependent dioxygenases including histone, DNA and RNA demethylases, resulting in histone, DNA and RNA hypermethylation and cell differentiation blockade. In addition, D-2HG is a biomarker suitable for the detection of IDH1/2 mutations at diagnosis, and is also predictive of clinical response. The U.S. Food and Drug Administration (FDA) approved ivosidenib, a mutant-IDH1 enzyme inhibitor, for patients with relapsed or refractory IDH1-mutated acute myeloid leukemia (AML) in 2018, and also as front-line therapy for newly diagnosed elderly patients 75 years or older or who are ineligible to receive intensive chemotherapy in 2019. Ivosidenib represents a novel drug class for targeted therapy in AML.


Assuntos
Glicina/análogos & derivados , Isocitrato Desidrogenase/genética , Leucemia Mieloide Aguda/tratamento farmacológico , Piridinas/uso terapêutico , Adulto , Idoso , Antineoplásicos/uso terapêutico , Inibidores Enzimáticos/uso terapêutico , Epigênese Genética , Glicina/uso terapêutico , Humanos , Mutação
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