RESUMO
Alzheimer's disease (AD) is a progressive and complex neurodegenerative disease. Acetylcholinesterase inhibitors (AChEIs) are a major class of drugs used in AD therapy. ROCK2, another promising target for AD, has been associated with the induction of neurogenesis via PTEN/AKT. This study aimed to characterize the therapeutic potential of a novel donepezil-tacrine hybrid compound (TA8Amino) to inhibit AChE and ROCK2 protein, leading to the induction of neurogenesis in SH-SY5Y cells. Experiments were carried out with undifferentiated and neuron-differentiated SH-SY5Y cells submitted to treatments with AChEIs (TA8Amino, donepezil, and tacrine) for 24 h or 7 days. TA8Amino was capable of inhibiting AChE at non-cytotoxic concentrations after 24 h. Following neuronal differentiation for 7 days, TA8Amino and donepezil increased the percentage of neurodifferentiated cells and the length of neurites, as confirmed by ß-III-tubulin and MAP2 protein expression. TA8Amino was found to participate in the activation of PTEN/AKT signaling. In silico analysis showed that TA8Amino can stably bind to the active site of ROCK2, and in vitro experiments in SH-SY5Y cells demonstrate that TA8Amino significantly reduced the expression of ROCK2 protein, contrasting with donepezil and tacrine. Therefore, these results provide important information on the mechanism underlying the action of TA8Amino with regard to multi-target activities.
Assuntos
Doença de Alzheimer , Inibidores da Colinesterase , Neuroblastoma , Doenças Neurodegenerativas , Quinases Associadas a rho , Humanos , Acetilcolinesterase/metabolismo , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Inibidores da Colinesterase/química , Donepezila/farmacologia , Neuroblastoma/tratamento farmacológico , Doenças Neurodegenerativas/tratamento farmacológico , PTEN Fosfo-Hidrolase , Quinases Associadas a rho/antagonistas & inibidores , Tacrina/químicaRESUMO
ERK1/2 inhibitors have attracted special attention concerning the ability of circumventing cases of innate or log-term acquired resistance to RAF and MEK kinase inhibitors. Based on the 4-aminoquinazoline pharmacophore of kinases, herein we describe the synthesis of 4-aminoquinazoline derivatives bearing a 1,2,3-triazole stable core to bridge different aromatic and heterocyclic rings using copper-catalysed azide-alkyne cycloaddition reaction (CuAAC) as a Click Chemistry strategy. The initial screening of twelve derivatives in tumoral cells (CAL-27, HN13, HGC-27, and BT-20) revealed that the most active in BT-20 cells (25a, IC50 24.6 µM and a SI of 3.25) contains a more polar side chain (sulfone). Furthermore, compound 25a promoted a significant release of lactate dehydrogenase (LDH), suggesting the induction of cell death by necrosis. In addition, this compound induced G0/G1 stalling in BT-20 cells, which was accompanied by a decrease in the S phase. Western blot analysis of the levels of p-STAT3, p-ERK, PARP, p53 and cleaved caspase-3 revealed p-ERK1/2 and p-STA3 were drastically decreased in BT-20 cells under 25a incubation, suggesting the involvement of these two kinases in the mechanisms underlying 25a-induced cell cycle arrest, besides loss of proliferation and viability of the breast cancer cell. Molecular docking simulations using the ERK-ulixertinib crystallographic complex showed compound 25a could potentially compete with ATP for binding to ERK in a slightly higher affinity than the reference ERK1/2 inhibitor. Further in silico analyses showed comparable toxicity and pharmacokinetic profiles for compound 25a in relation to ulixertinib.
Assuntos
Antineoplásicos/farmacologia , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , Simulação de Acoplamento Molecular , Inibidores de Proteínas Quinases/farmacologia , Quinazolinas/farmacologia , Triazóis/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , Estrutura Molecular , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Quinazolinas/química , Relação Estrutura-Atividade , Triazóis/químicaRESUMO
Human T cell lymphotropic virus type 1 (HTLV-1) is a human retrovirus that infects approximately 10-20 million people worldwide and causes an aggressive neoplasia (adult T-cell leukemia/lymphoma - ATL). Therapeutic approaches for the treatment of ATL have variable effectiveness and poor prognosis, thus requiring strategies to identify novel compounds with activity on infected cells. In this sense, we initially screened a small series of 25 1,2,3-triazole derivatives to discover cell proliferation inhibitors and apoptosis inducers in HTLV-1-infected T-cell line (MT-2) for further assessment of their effect on viral tax activity through inducible-tax reporter cell line (Jurkat LTR-GFP). Eight promising compounds (02, 05, 06, 13, 15, 21, 22 and 25) with activity ≥70% were initially selected, based on a suitable cell-based assay using resazurin reduction method, and evaluated towards cell cycle, apoptosis and Tax/GFP expression analyses through flow cytometry. Compound 02 induced S phase cell cycle arrest and compounds 05, 06, 22 and 25 promoted apoptosis. Remarkably, compounds 22 and 25 also reduced GFP expression in an inducible-tax reporter cell, which suggests an effect on Tax viral protein. More importantly, compounds 02, 22 and 25 were not cytotoxic in human hepatoma cell line (Huh-7). Therefore, the discovery of 3 active and non-cytotoxic compounds against HTLV-1-infected cells can potentially contribute, as an initial promising strategy, to the development process of new drugs against ATL.
Assuntos
Antivirais/farmacologia , Produtos do Gene tax/antagonistas & inibidores , Compostos Heterocíclicos/farmacologia , Vírus Linfotrópico T Tipo 1 Humano/efeitos dos fármacos , Triazóis/farmacologia , Antivirais/síntese química , Antivirais/química , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Produtos do Gene tax/metabolismo , Compostos Heterocíclicos/química , Humanos , Estrutura Molecular , Relação Estrutura-Atividade , Triazóis/químicaRESUMO
Losartan is widely used in clinics to treat cardiovascular related diseases by selectively blocking the angiotensin II type 1 receptors (AT1Rs), which regulate the renin-angiotensin system (RAS). Therefore, monitoring the physiological and pathological biodistribution of AT1R using positron emission tomography (PET) might be a valuable tool to assess the functionality of RAS. Herein, we describe the synthesis and characterization of two novel losartan derivatives PET tracers, [18F]fluoroethyl-losartan ([18F]FEtLos) and [18F]ammoniomethyltrifluoroborate-losartan ([18F]AMBF3Los). [18F]FEtLos was radiolabeled by 18F-fluoroalkylation of losartan potassium using the prosthetic group 2-[18F]fluoroethyl tosylate; whereas [18F]AMBF3Los was prepared following an one-step 18F-19F isotopic exchange reaction, in an overall yield of 2.7 ± 0.9% and 11 ± 4%, respectively, with high radiochemical purity (>95%). Binding competition assays in AT1R-expressing membranes showed that AMBF3Los presented an almost equivalent binding affinity (Ki 7.9 nM) as the cold reference Losartan (Ki 1.5 nM), unlike FEtLos (Ki 2000 nM). In vitro and in vivo assays showed that [18F]AMBF3Los displayed a good binding affinity for AT1R-overexpressing CHO cells and was able to specifically bind to renal AT1R. Hence, our data demonstrate [18F]AMBF3Los as a new tool for PET imaging of AT1R with possible applications for the diagnosis of cardiovascular, inflammatory and cancer diseases.
Assuntos
Radioisótopos de Flúor , Losartan/análogos & derivados , Losartan/química , Imagem Molecular , Receptor Tipo 1 de Angiotensina/química , Receptor Tipo 1 de Angiotensina/metabolismo , Animais , Camundongos , Modelos Animais , Imagem Molecular/métodos , Estrutura Molecular , Tomografia por Emissão de Pósitrons , Ligação Proteica , Compostos Radiofarmacêuticos , Distribuição TecidualRESUMO
Acetylcholinesterase (AChE) is the key enzyme targeted in Alzheimer's disease (AD) therapy, nevertheless butyrylcholinesterase (BuChE) has been drawing attention due to its role in the disease progression. Thus, we aimed to synthesize novel cholinesterases inhibitors considering structural differences in their peripheral site, exploiting a moiety replacement approach based on the potent and selective hAChE drug donepezil. Hence, two small series of N-benzylpiperidine based compounds have successfully been synthesized as novel potent and selective hBuChE inhibitors. The most promising compounds (9 and 11) were not cytotoxic and their kinetic study accounted for dual binding site mode of interaction, which is in agreement with further docking and molecular dynamics studies. Therefore, this study demonstrates how our strategy enabled the discovery of novel promising and privileged structures. Remarkably, compound 11 proved to be one of the most potent (0.17â¯nM) and selective (>58,000-fold) hBuChE inhibitor ever reported.
Assuntos
Butirilcolinesterase/metabolismo , Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacologia , Piperidinas/química , Piperidinas/farmacologia , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/enzimologia , Inibidores da Colinesterase/síntese química , Química Click , Desenho de Fármacos , Descoberta de Drogas , Humanos , Simulação de Acoplamento Molecular , Piperidinas/síntese química , Relação Estrutura-AtividadeRESUMO
2-Nitroimidazole-based hypoxia imaging tracers such as 18 F-FMISO are normally imaged at late time points (several hours post-injection) due to their slow clearance from background tissues. Here, we investigated if a hydrophilic zwitterion-based ammoniomethyl-trifluoroborate derivative of 2-nitroimidazole, 18 F-AmBF3 -Bu-2NI, could have the potential to image tumor hypoxia at earlier time points. AmBF3 -Bu-2NI was prepared in 4 steps. 18 F labeling was conducted via 18 F-19 F isotope exchange reaction, and 18 F-AmBF3 -Bu-2NI was obtained in 14.8 ± 0.4% (n = 3) decay-corrected radiochemical yield with 24.5 ± 5.2 GBq/µmol specific activity and >99% radiochemical purity. Imaging and biodistribution studies in HT-29 tumor-bearing mice showed that 18 F-AmBF3 -Bu-2NI cleared quickly from blood and was excreted via the hepatobiliary and renal pathways. However, the tumor was not visualized in PET images until 3 hours post-injection due to low tumor uptake (0.54 ± 0.13 and 0.19 ± 0.04%ID/g at 1 and 3 hours post-injection, respectively). The low tumor uptake is likely due to the highly hydrophilic motif of ammoniomethyl-trifluoroborate that prevents free diffusion of 18 F-AmBF3 -Bu-2NI across the cell membrane. Our results suggest that highly hydrophilic 18 F-labeled ammoniomethyl-trifluoroborate derivatives might not be suitable for imaging intracellular targets including nitroreductase, a common tumor hypoxia imaging target.
Assuntos
Radioisótopos de Flúor/química , Neoplasias Experimentais/diagnóstico por imagem , Nitroimidazóis/química , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos/síntese química , Animais , Compostos de Boro/química , Hipóxia Celular , Células HT29 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Compostos Radiofarmacêuticos/farmacocinética , Distribuição TecidualRESUMO
This study presents the synthesis of the novel protected O-glycosylated amino acid derivatives 1 and 2, containing ßGalNAc-SerOBn and ßGalNAc-ThrOBn units, respectively, as mimetics of the natural Tn antigen (αGalNAc-Ser/Thr), along with the solid-phase assembly of the glycopeptides NHAcSer-Ala-Pro-Asp-Thr[αGalNAc]-Arg-Pro-Ala-Pro-Gly-BSA (3-BSA) and NHAcSer-Ala-Pro-Asp-Thr[ßGalNAc]-Arg-Pro-Ala-Pro-Gly-BSA (4-BSA), bearing αGalNAc-Thr or ßGalNAc-Thr units, respectively, as mimetics of MUC1 tumor mucin glycoproteins. According to ELISA tests, immunizations of mice with ßGalNAc-glycopeptide 4-BSA induced higher sera titers (1:320 000) than immunizations with αGalNAc-glycopeptide 3-BSA (1:40 000). Likewise, flow cytometry assays showed higher capacity of the obtained anti-glycopeptide 4-BSA antibodies to recognize MCF-7 tumor cells. Cross-recognition between immunopurified anti-ßGalNAc antibodies and αGalNAc-glycopeptide and vice versa was also verified. Lastly, molecular dynamics simulations and surface plasmon resonance (SPR) showed that ßGalNAc-glycopeptide 4 can interact with a model antitumor monoclonal antibody (SM3). Taken together, these data highlight the improved immunogenicity of the unnatural glycopeptide 4-BSA, bearing ßGalNAc-Thr as Tn antigen isomer.
Assuntos
Anticorpos Monoclonais/metabolismo , Formação de Anticorpos/efeitos dos fármacos , Antígenos Glicosídicos Associados a Tumores/química , Mucina-1/metabolismo , Mucina-1/farmacologia , Animais , Antineoplásicos/síntese química , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Bioensaio/normas , Sequência de Carboidratos , Humanos , Isomerismo , Células MCF-7 , Camundongos , Modelos Biológicos , Simulação de Dinâmica Molecular , Mucina-1/química , Técnicas de Síntese em Fase Sólida , Ressonância de Plasmônio de SuperfícieRESUMO
The synthesis of the O-3 triazole-linked galactosyl arylsulfonamides 1-7 as potential inhibitors of Trypanosoma cruzi cell invasion is described. These target compounds were synthesized by Cu(I)-catalysed azide-alkyne cycloaddition reaction ('click chemistry') between different azide arylsulfonamides and the alkyne-based sugar 3-O-propynyl-ßGalOMe. Inhibition assays of T. cruzi cell invasion with compounds 1-7 showed reduced values of infection index (â¼20) for compounds 3 and 5, bearing the corresponding 5-methylisoxazole and 2,4-dimethoxypyrimidine groups, which also presented higher binding affinities to galectin-3 (EC50 17-18⯵M) in Corning Epic label-free assays. In agreement with experimental results, the assessment of the theoretical binding of compounds 1-7 to galectin-3 by MM/PBSA method displayed higher affinities for compounds 3 (-9.7â¯kcal/mol) and 5 (-11.1â¯kcal/mol). Overall, these achievements highlight compounds 3 and 5 as potential T. cruzi cell invasion blockers by means of a galectin-3 binding-related mechanism, revealing galectin-3 as an important host target for design of novel anti-trypanosomal agents.
Assuntos
Inibidores Enzimáticos/farmacologia , Fibroblastos/efeitos dos fármacos , Galectina 3/metabolismo , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Animais , Sítios de Ligação/efeitos dos fármacos , Proteínas Sanguíneas , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Fibroblastos/parasitologia , Galactose/química , Galactose/farmacologia , Galectinas , Glicoproteínas/antagonistas & inibidores , Glicoproteínas/metabolismo , Haplorrinos , Humanos , Estrutura Molecular , Neuraminidase/antagonistas & inibidores , Neuraminidase/metabolismo , Relação Estrutura-Atividade , Sulfonamidas/química , Sulfonamidas/farmacologia , Triazóis/química , Triazóis/farmacologia , Tripanossomicidas/síntese química , Tripanossomicidas/química , Trypanosoma cruzi/enzimologiaRESUMO
Chagas, or American trypanosomiasis, remains an important public health problem in developing countries. In the last decade, trans-sialidase has become a pharmacological target for new anti-Chagas drugs. In this work, the aims were to design and find a new series of benzoic acid derivatives as trans-sialidase (TS) inhibitors and anti-trypanosomal agents. Three compounds (14, 18, and 19) sharing a para-aminobenzoic acid moiety showed more potent trypanocidal activity than the commercially available drugs nifurtimox and benznidazole in both strains: the lysis concentration of 50% of the population (LC50) was <0.15 µM on the NINOA strain, and LC50 < 0.22 µM on the INC-5 strain. Additionally, compound 18 showed a moderate inhibition (47%) on the trans-sialidase enzyme and a binding model similar to DANA (pattern A).
Assuntos
Benzoatos/farmacologia , Inibidores Enzimáticos/farmacologia , Glicoproteínas/química , Neuraminidase/química , Tripanossomicidas/farmacologia , Animais , Benzoatos/síntese química , Benzoatos/química , Desenho de Fármacos , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Glicoproteínas/antagonistas & inibidores , Camundongos , Modelos Moleculares , Simulação de Acoplamento Molecular , Estrutura Molecular , Neuraminidase/antagonistas & inibidores , Relação Estrutura-Atividade , Tripanossomicidas/síntese química , Tripanossomicidas/química , Trypanosoma cruzi/efeitos dos fármacosRESUMO
Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder worldwide. Currently, the only strategy for palliative treatment of AD is to inhibit acetylcholinesterase (AChE) in order to increase the concentration of acetylcholine in the synaptic cleft. Evidence indicates that AChE also interacts with the ß-amyloid (Aß) protein, acting as a chaperone and increasing the number and neurotoxicity of Aß fibrils. It is known that AChE has two binding sites: the peripheral site, responsible for the interactions with Aß, and the catalytic site, related with acetylcholine hydrolysis. In this work, we reported the synthesis and biological evaluation of a library of new tacrine-donepezil hybrids, as a potential dual binding site AChE inhibitor, containing a triazole-quinoline system. The synthesis of hybrids was performed in four steps using the click chemistry strategy. These compounds were evaluated as hAChE and hBChE inhibitors, and some derivatives showed IC50 values in the micro-molar range and were remarkably selective towards hAChE. Kinetic assays and molecular modeling studies confirm that these compounds block both catalytic and peripheral AChE sites. These results are quite interesting since the triazole-quinoline system is a new structural scaffold for AChE inhibitors. Furthermore, the synthetic approach is very efficient for the preparation of target compounds, allowing a further fruitful new chemical library optimization.
Assuntos
Inibidores da Colinesterase/química , Quinolinas/química , Triazóis/química , Acetilcolinesterase/química , Doença de Alzheimer/tratamento farmacológico , Domínio Catalítico , Química Click , Humanos , Cinética , Simulação de Acoplamento Molecular , Ligação ProteicaRESUMO
This work describes the synthesis of the 1,2,3-triazole amino acid-derived-3-O-galactosides 1-6 and the 1,2,3-triazole di-lactose-derived glycoconjugate 7 as potential galectin-3 inhibitors. The target compounds were synthesized by Cu(I)-catalyzed azide-alkyne cycloaddition reaction ('click chemistry') between the azido-derived amino acids N3-ThrOBn, N3-PheOBn, N3-N-Boc-TrpOBn, N3-N-Boc-LysOBn, N3-O-tBu-AspOBn and N3-l-TyrOH, and the corresponding alkyne-based sugar 3-O-propynyl-GalOMe, as well as by click chemistry reaction between the azido-lactose and 2-propynyl lactose. Surface plasmon resonance (SPR) assays showed that all synthetic glycoconjugates 1-7 bound to galectin-3 with high affinity, but the highest binders were the amino acids-derived glycoconjugates 2 (KD 7.96µM) and 4 (KD 4.56µM), and the divalent lactoside 7 (KD1 0.15µM/KD2 19µM). Molecular modeling results were in agreement with SPR assays, since more stable interactions with galectin-3 were identified for glycoconjugates 2, 4 and 7. Regarding compounds 2 and 4, they established specific cation-π (Arg144) and ionic (Asp148) interactions, whereas glycoconjugate 7 was capable to bridge two independent galectin-3 CRDs, creating a non-covalent cross-link between two monomers and, thus, reaching a submicromolar affinity towards galectin-3.
Assuntos
Aminoácidos/química , Galactosídeos/química , Galectina 3/química , Glicoconjugados/química , Triazóis/química , Alcinos/química , Azidas/química , Proteínas Sanguíneas , Química Click , Reação de Cicloadição , Galectinas , Glicoconjugados/síntese química , Humanos , Lactose/química , Ligantes , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Ligação ProteicaRESUMO
The current treatment of Chagas disease is based on the use of two drugs, nifurtimox and benznidazole, which present limited efficacy in the chronic stage of the disease and toxic side effects. Although some progress has been made in the development of new drugs to treat this disease, the discovery of novel compounds is urgently required. In this work we report the synthesis and biological evaluation of 1,2,3-triazole-based analogues of benznidazole. A small series of 27 compounds was successfully synthesized via microwave-assisted copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) and ruthenium-catalyzed azide-alkyne cycloaddition (RuAAC) from N-benzyl-2-azidoacetamide (1) and a set of commercial terminal alkynes. Analogues 24 (IC50 40 µM) and 28 (IC50 50 µM) showed comparable activities to benznidazole (IC50 34 µM) against trypomastigote form and analogue 15 (IC50 7 µM) was found to be the most active. Regarding the cytotoxicity assessment of the series, most compounds were not cytotoxic. This work shows that the designed strategy is efficiently capable of generating novel benzindazole analogues and reveals one analogue is more active than benznidazole.
Assuntos
Nitroimidazóis/química , Triazóis/química , Tripanossomicidas/química , Catálise , Química Click , Cobre/química , Reação de Cicloadição , Micro-Ondas , Nitroimidazóis/síntese química , Nitroimidazóis/farmacologia , Rutênio/química , Relação Estrutura-Atividade , Tripanossomicidas/síntese química , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacosRESUMO
Reaction of 2-(2-(2-azidoethoxy)ethoxy)ethyl 6-O-(prop-2-ynyl)-ß-d-galactopyranoside (7) under CuAAC conditions gives rise to mixed cyclic and linear triazole-linked oligomers, with individual compounds up to d.p. 5 isolable, along with mixed larger oligomers. The linear compounds resolve en bloc from the cyclic materials by RP HPLC, but are separable by gel permeation chromatography. The triazole-linked oligomers-pseudo-galactooligomers-were demonstrated to be acceptor substrates for the multi-copy cell surface trans-sialidase of the human parasite Trypanosoma cruzi. In addition, these multivalent TcTS ligands were able to block macrophage invasion by T. cruzi.
RESUMO
This study describes the synthesis of glycopeptides NHAc[ßGal]-(Thr)2 -[αGalNAc]-(Thr)2 -[αGlcNAc]-(Thr)2 Gly-OVA (1-OVA) and NHAc[ßGal-αGalNAc]-(Thr)3 -[αLacNAc]-(Thr)3 -Gly-OVA (2-OVA) as mimetics of both T. cruzi and tumor mucin glycoproteins. These glycopeptides were obtained by solid-phase synthesis, which involved the prior preparation of the protected glycosyl amino acids αGlcNAc-ThrOH (3), αGalNAc-ThrOH (4), ßGal-ThrOH (5), αLacNAc-ThrOH (6), and ßGal-αGalNAc-ThrOH (7) through glycosylation reactions. Immunizations of mice with glycopeptides 1-OVA and 2-OVA induced high antibody titers (1:16 000), as verified by ELISA tests, whereas flow cytometry assays showed the capacity of the obtained anti-glycopeptides 1-OVA and 2-OVA antibodies to recognize both T. cruzi and MCF-7 tumor cells. In addition, antisera induced by glycopeptides 1-OVA and 2-OVA were also able to inhibit T. cruzi fibroblast cell invasion (70 %) and to induce antibody-mediated cellular cytotoxicity (ADCC) against MCF-7 cells, with 50 % reduction of cell viability.
Assuntos
Anticorpos/imunologia , Anticorpos/farmacologia , Doença de Chagas/terapia , Glicopeptídeos/imunologia , Mucinas/imunologia , Neoplasias/terapia , Trypanosoma cruzi/efeitos dos fármacos , Sequência de Aminoácidos , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Doença de Chagas/imunologia , Doença de Chagas/parasitologia , Glicopeptídeos/administração & dosagem , Glicopeptídeos/química , Humanos , Imunização , Camundongos , Mucinas/administração & dosagem , Mucinas/química , Neoplasias/química , Neoplasias/imunologia , Ovalbumina/administração & dosagem , Ovalbumina/química , Ovalbumina/imunologia , Trypanosoma cruzi/química , Trypanosoma cruzi/imunologia , Trypanosoma cruzi/fisiologiaRESUMO
The trans-sialidase of Trypanosoma cruzi (TcTS) is a surface enzyme that modifies the parasite glycocalyx covering it with sialic acid. This process is essential to adhesion and invasion mechanisms in life cycle of the protozoan in the human host, making TcTS a very attractive molecular target for drug design. Using the TcTS substrate 3'-sialyllactose as prototype, D-galactose-derived potential inhibitors of TcTS were designed using strategies of molecular modification. Ten new aryl galactosides modified at carbon-3 were synthesized employing classical carbohydrate chemistry and dibutyltin oxide method for regioselective 3-O-alkylations and evaluated against TcTS by spectrofluorimetry. The 4-methoxycarbonyl-2-nitrophenyl 3-O-carboxymethyl-ß-D-galactopyranoside was the most active compound inhibiting 21% of TcTS enzymatic activity at 1 mM.
Assuntos
Desenho de Fármacos , Inibidores Enzimáticos/farmacologia , Galactose/farmacologia , Glicoproteínas/antagonistas & inibidores , Neuraminidase/antagonistas & inibidores , Trypanosoma cruzi/enzimologia , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Galactose/síntese química , Galactose/química , Glicoproteínas/metabolismo , Simulação de Acoplamento Molecular , Estrutura Molecular , Neuraminidase/metabolismo , Relação Estrutura-AtividadeRESUMO
Congenital hypothyroidism (CH) leads to growth and development delays and is preventable with early treatment. Neonatal screening for CH was initiated in Portugal in 1981. This study examines the history of CH screening in the country. Data were obtained from annual reports and from the national database of neonatal screening laboratory. The CH screening strategy primarily relies on the thyroid-stimulating hormone (TSH), followed by total thyroxine measurement as the second tier for confirmation. The TSH cutoff started at 90 mIU/L, decreasing to the actual 10 mIU/L. The coverage of the screening program has increased rapidly; although voluntary, it reached about 90% in 6 years and became universal in 10 years. Guideline and cutoff updates led to the identification of over 200 additional cases, resulting in specific retesting protocols for preterm and very-low-birth-weight babies. The actual decision tree considers CH when TSH levels are above 40 mIU/L. Data from the CH screening also provide an indication of the iodine status of the population, which is presently indicative of iodine insufficiency. The Portuguese neonatal screening for CH is a history of success. It has rapidly and continuously adapted to changes in knowledge and has become a universal voluntary practice within a few years.
RESUMO
This work addresses the synthesis and biological evaluation of glycosyl diketopiperazines (DKPs) cyclo[Asp-(αGalNAc)Ser] 3 and cyclo[Asp-(αGalNAc)Thr] 4 for the development of novel anti-trypanosomal agents and Trypanosoma cruzi trans-sialidase (TcTS) inhibitors. The target compounds were synthetized by coupling reactions between glycosyl amino acids αGalNAc-Ser 7 or αGalNAc-Thr 8 and the amino acid (O-tBu)-Asp 17, followed by one-pot deprotection-cyclisation reaction in the presence of 20% piperidine in DMF. The protected glycosyl amino acid intermediates 7 and 8 were, in turn, obtained by α-selective, HgBr2-catalysed glycosylation reactions of Fmoc-Ser/Thr benzyl esters 12/14 with αGalN3Cl 11, being, subsequently, fully deprotected for comparative biological assays. The DKPs 3 and 4 showed relevant anti-trypanosomal effects (IC50 282-124 µM), whereas glycosyl amino acids 1 and 2 showed better TcTS inhibition (57-79%) than the corresponding DKPs (13-25%).
Assuntos
Acetilgalactosamina/química , Acetilgalactosamina/farmacologia , Dicetopiperazinas/química , Dicetopiperazinas/farmacologia , Tripanossomicidas/química , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Acetilgalactosamina/síntese química , Animais , Linhagem Celular , Células Cultivadas , Doença de Chagas/tratamento farmacológico , Doença de Chagas/parasitologia , Dicetopiperazinas/síntese química , Glicoproteínas/antagonistas & inibidores , Glicoproteínas/metabolismo , Glicosilação , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Mucinas/química , Mucinas/farmacologia , Neuraminidase/antagonistas & inibidores , Neuraminidase/metabolismo , Tripanossomicidas/síntese química , Trypanosoma cruzi/enzimologiaRESUMO
INTRODUCTION: Newborn screening (NBS) in Portugal is a significant public health measure to provide early detection for specific disorders so that early treatment is possible. Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder that causes degeneration of anterior horn cells in the human spinal cord and subsequent loss of motor neurons. Its incidence is estimated in 1.6000-11.800 live births. A pilot study on 100.000 newborns is being carried out at the neonatal screening laboratory with the aim of determining the specificity, sensitivity, and feasibility of the SMA screening at the NBS laboratory in Portugal. METHODS: The study presented here was based on data obtained from neonatal screening, involving the analysis of 25.000 newborns. SMA screening is performed by a qualitative detection of exon 7 of the SMN1 gene. The assay was performed using a commercially available real-time PCR, the Eonis SMN1, TREC, and KREC kit. RESULTS/CASE REPORT: The dried blood spots of a total of 25.000 newborns were tested; among these newborns, two were diagnosed as having SMA with survival motor neuron 1 (SMN1) deletion. These two SMA-positive samples were sent to a specialized clinical centre and a peripheral blood sample was sent to the reference laboratory for confirmation of the exon 7 deletion and determination of the SMN2 copy number. CONCLUSION: Early diagnosis and intervention are important for SMA treatment to be effective; the treatment should be started at the pre-symptomatic stage of SMA. Thus, newborn screening for SMA is strongly recommended. Currently, targeted therapies for SMA are available, and attempts are being made worldwide to include SMA screening in newborns.
RESUMO
Mild-to-moderate iodine deficiency during pregnancy is prevalent worldwide, but its consequences for maternal and child health are not clear. We aimed to investigate the impact of maternal iodine intake during pregnancy on the child's growth and neurodevelopment. This study involved a cohort of 11-year-old children (n = 70) whose mothers had participated in an iodine intake survey during pregnancy. Gestational, neonatal, anthropometric, intelligence quotient (IQ), and socioeconomic parameters were analyzed according to maternal urinary iodine concentration (UIC). There was a positive linear trend of current height Z-score, full-scale IQ, verbal IQ, family income, maternal education, and a negative trend of neonatal TSH levels with increasing maternal UIC levels. However, regression analysis indicated that maternal UIC was not an independent predictor of any gestational, neonatal, or childhood development parameter. Only maternal school education was positively associated with child height and IQ. In conclusion, we did not find any evidence of a direct effect of maternal iodine intake during pregnancy on the long-term growth and neurodevelopment of children. The results suggest that socioeconomic factors are important confounding factors that affect both maternal iodine intake and child development and must be considered when investigating the association between maternal iodine intake and child outcomes.
Assuntos
Iodo , Gravidez , Feminino , Recém-Nascido , Humanos , Criança , Seguimentos , Desenvolvimento Infantil , Mães , Estado NutricionalRESUMO
This work describes the synthesis of a series of sialylmimetic neoglycoconjugates represented by 1,4-disubstituted 1,2,3-triazole-sialic acid derivatives containing galactose modified at either C-1 or C-6 positions, glucose or gulose at C-3 position, and by the amino acid derivative 1,2,3-triazole fused threonine-3-O-galactose as potential TcTS inhibitors and anti-trypanosomal agents. This series was obtained by Cu(I)-catalysed azide-alkyne cycloaddition reaction ('click chemistry') between the azido-functionalized sugars 1-N(3)-Gal (commercial), 6-N(3)-Gal, 3-N(3)-Glc and 3-N(3)-Gul with the corresponding alkyne-based 2-propynyl-sialic acid, as well as by click chemistry reaction between the amino acid N(3)-ThrOBn with 3-O-propynyl-GalOMe. The 1,2,3-triazole linked sialic acid-6-O-galactose and the sialic acid-galactopyranoside showed high Trypanosoma cruzitrans-sialidase (TcTS) inhibitory activity at 1.0mM (approx. 90%), whilst only the former displayed relevant trypanocidal activity (IC(50) 260µM). These results highlight the 1,2,3-triazole linked sialic acid-6-O-galactose as a prototype for further design of new neoglycoconjugates against Chagas' disease.