Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 757
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Life Sci ; 248: 117471, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32112868

RESUMO

AIMS: This study aimed to explore the protective effects and possible mechanisms of baicalein on Aß25-35-induced toxicity. MAIN METHODS: Thioflavin-T (Th-T) dye was used to determine the effects of baicalein on Aß25-35 aggregation in vitro. PC12 cells were stimulated with Aß25-35, then the effects of baicalein on apoptosis, mitochondrial membrane potential (MMP), adenosine triphosphate (ATP), mitochondrial respiratory complex I, reactive oxygen species (ROS) and nitric oxide (NO) levels were determined. Moreover, LC-MS metabolomics approach was used to detect metabolic changes induced by baicalein in Aß25-35-injured PC12 cells. KEY FINDINGS: The results showed that baicalein could inhibit the aggregation of Aß25-35 in vitro. Furthermore, pretreatment with baicalein significantly prevented Aß25-35-induced cell apoptosis, as manifested by increasing the levels of MMP, ATP and mitochondrial respiratory complex I, decreasing the contents of ROS and NO. LC-MS metabolomics revealed that baicalein can regulate 5 metabolites, mainly involving two metabolic pathways, arginine and proline metabolism, nicotinate and nicotinamide metabolism. SIGNIFICANCE: Our study revealed that baicalein has a protective effect on Aß25-35-induced neurotoxicity in PC12 cells, which may be related to inhibition of apoptosis and metabolic disorders.


Assuntos
Peptídeos beta-Amiloides/antagonistas & inibidores , Apoptose/efeitos dos fármacos , Flavanonas/farmacologia , Mitocôndrias/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Fragmentos de Peptídeos/antagonistas & inibidores , Trifosfato de Adenosina/biossíntese , Peptídeos beta-Amiloides/toxicidade , Animais , Arginina/metabolismo , Complexo I de Transporte de Elétrons/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/metabolismo , Niacina/metabolismo , Niacinamida/metabolismo , Óxido Nítrico/antagonistas & inibidores , Óxido Nítrico/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Células PC12 , Fragmentos de Peptídeos/toxicidade , Prolina/metabolismo , Agregados Proteicos/efeitos dos fármacos , Ratos , Espécies Reativas de Oxigênio/antagonistas & inibidores , Espécies Reativas de Oxigênio/metabolismo
2.
Chem Commun (Camb) ; 56(21): 3187-3190, 2020 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-32068230

RESUMO

The isomers vescalagin and castalagin protect SH-SY5Y cells from Aß42-mediated death. This is achieved better by vescalagin due to the spatial organization of its OH group at the C1 position of the glycosidic chain, improving its capacity to remodel the secondary structure of toxic Aß42 oligomers.


Assuntos
Peptídeos beta-Amiloides/antagonistas & inibidores , Taninos Hidrolisáveis/farmacologia , Polifenóis/antagonistas & inibidores , Peptídeos beta-Amiloides/química , Peptídeos beta-Amiloides/toxicidade , Morte Celular/efeitos dos fármacos , Humanos , Taninos Hidrolisáveis/química , Estrutura Molecular , Polifenóis/química , Polifenóis/toxicidade , Agregados Proteicos/efeitos dos fármacos , Estrutura Secundária de Proteína , Células Tumorais Cultivadas
3.
Chem Biol Interact ; 315: 108884, 2020 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-31678113

RESUMO

Quinolinic acid (QA) known as a neuro-active metabolite associated with the kynurenine pathway. At high concentrations, QA is often involved in the initiation and development of several human neurologic diseases, like Alzheimer's disease. Because of the QA action as the NMDA receptor, it is considered as a potent excitotoxin in vivo. Since it is probable that different mechanisms are employed by QA, activation of NMDA receptors cannot fully explain the revealed toxicity and it is even believed that there are multiple unknown mechanisms/targets leading to QA cytotoxicity. Herein we report accelerated amyloid oligomerization of 1N4R Tau under the effect of QA, in vitro, then the molecular structure, morphology and toxicity of the protein aggregate were documented by using various theoretical/experimental approaches. The possible mechanism of action of QA-induced Tau oligomerization has also been explored.


Assuntos
Amiloide/metabolismo , Neurotoxinas/efeitos adversos , Agregados Proteicos/efeitos dos fármacos , Piridinas/efeitos adversos , Ácido Quinolínico/efeitos adversos , Doença de Alzheimer/metabolismo , Humanos , Cinurenina/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo
4.
Chemistry ; 26(8): 1871-1879, 2020 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-31804737

RESUMO

Mounting evidence supports the role of amyloidogenesis, oxidative stress, and metal dyshomeostasis in the development of neurodegenerative disorders. Parkinson's Disease is characterized by α-synuclein (αSyn) accumulation and aggregation in brain regions, also promoted by Cu2+ . αSyn is modified by reactive carbonyl species, including acrolein (ACR). Notwithstanding these findings, the interplay between ACR, copper, and αSyn has never been investigated. Therefore, we explored more thoroughly the effects of ACR on αSyn using an approach based on LC-MS/MS analysis. We also evaluated the influence of Cu2+ on the protein carbonylation and how the ACR modification impacts the Cu2+ binding and the production of Reactive Oxygen Species (ROS). Finally, we investigated the effects of ACR and Cu2+ ions on the αSyn aggregation by dynamic light scattering and fluorescence assays. Cu2+ regioselectively inhibits the modification of His50 by ACR, the carbonylation lowers the affinity of His50 for Cu2+ and ACR inhibits αSyn aggregation both in the presence and in the absence of Cu2+ .


Assuntos
Acroleína/química , Cobre/química , alfa-Sinucleína/química , Acroleína/farmacologia , Cromatografia Líquida de Alta Pressão , Cobre/farmacologia , Difusão Dinâmica da Luz , Humanos , Estresse Oxidativo/efeitos dos fármacos , Agregados Proteicos/efeitos dos fármacos , Carbonilação Proteica/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Espectrometria de Massas em Tandem , alfa-Sinucleína/análise , alfa-Sinucleína/metabolismo
5.
Chem Asian J ; 15(1): 91-97, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31778040

RESUMO

The properties of eumelanin-like particles (EMPs) and pheomelanin-like particles (PMPs) in regulating the process of amyloid formation of amyloid-beta 42 (Aß42) were examined. EMPs and PMPs are effective both in interfering with amyloid aggregation of Aß42 and in remodeling matured Αß42 fibers. The results suggest that some (but not all) molecular species consisting of melanin-like particles (MPs) are responsible for their inhibiting property toward amyloid formation, and the influence is likely manifested by long-range interactions. Incubating preformed Aß42 fibers with catechols or MPs leads to the formation of mesh-like, interconnected Aß42 fibers encapsulated with melanin-like material. MPs are kinetically more effective than catechol monomers in this process, and a detailed investigation reveals that 4,5-dihydroxyindole, a major intermediate in the formation of melanin-like species, and its derivatives are mainly responsible for remodeling amyloid fibers.


Assuntos
Peptídeos beta-Amiloides/química , Peptídeos beta-Amiloides/metabolismo , Melaninas/farmacologia , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Agregados Proteicos/efeitos dos fármacos , Agregação Patológica de Proteínas , Relação Dose-Resposta a Droga , Humanos , Melaninas/síntese química , Melaninas/química , Tamanho da Partícula , Relação Estrutura-Atividade , Propriedades de Superfície
6.
Chemistry ; 26(8): 1834-1845, 2020 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-31773792

RESUMO

Chemical chaperones prevent protein aggregation. However, the use of chemical chaperones as drugs against diseases due to protein aggregation is limited by the very high active concentrations (mm range) required to mediate their effect. One of the most common chemical chaperones is 4-phenylbutyric acid (4-PBA). Despite its unfavorable pharmacokinetic properties, 4-PBA was approved as a drug to treat ornithine cycle diseases. Here, we report that 2-isopropyl-4-phenylbutanoic acid (5) has been found to be 2-10-fold more effective than 4-PBA in several in vitro models of protein aggregation. Importantly, compound 5 reduced the secretion rate of autism-linked Arg451Cys Neuroligin3 (R451C NLGN3).


Assuntos
Fenilbutiratos/química , Proteínas/química , Animais , Moléculas de Adesão Celular Neuronais/química , Moléculas de Adesão Celular Neuronais/genética , Moléculas de Adesão Celular Neuronais/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Células HEK293 , Humanos , Proteínas de Membrana/química , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Mutagênese Sítio-Dirigida , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Células PC12 , Fenilbutiratos/farmacologia , Agregados Proteicos/efeitos dos fármacos , Dobramento de Proteína , Proteínas/metabolismo , Ratos
7.
Eur J Med Chem ; 186: 111880, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31753513

RESUMO

To date, drugs that hit a single target are inadequate for the treatment of neurodegenerative diseases, such as Alzheimer's or Parkinson's diseases. The development of multitarget ligands, able to interact with the different pathways involved in the progession of these disorders, represents a great challenge for medicinal chemists. In this context, we report here the synthesis and biological evaluation of phenol-lipoyl hybrids (SV1-13), obtained via a linking strategy, to take advantage of the synergistic effect due to the antioxidant portions and anti-amyloid properties of the single constituents present in the hybrid molecule. Biological results showed that SV5 and SV10 possessed the best protective activity against Aß1-42 induced neurotoxicity in differentiated SH-SY5Y cells. SV9 and SV10 showed remarkable antioxidant properties due to their ability to counteract the damage caused by H2O2 in SHSY-5Y-treated cells. Hovewer, SV5, showing moderate antioxidant and good neuroprotective activities, resulted the best candidate for further experiments since it also resulted stable both simulated and plasma fluids.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides/antagonistas & inibidores , Antioxidantes/farmacologia , Fármacos Neuroprotetores/farmacologia , Fragmentos de Peptídeos/antagonistas & inibidores , Fenóis/farmacologia , Ácido Tióctico/farmacologia , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Antioxidantes/síntese química , Antioxidantes/química , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Estrutura Molecular , Fármacos Neuroprotetores/síntese química , Fármacos Neuroprotetores/química , Fragmentos de Peptídeos/metabolismo , Fenóis/síntese química , Fenóis/química , Agregados Proteicos/efeitos dos fármacos , Relação Estrutura-Atividade , Ácido Tióctico/síntese química , Ácido Tióctico/química , Células Tumorais Cultivadas
8.
Inorg Chem ; 59(1): 837-846, 2020 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-31855423

RESUMO

Competitive Cu(II)-binding studies have been carried out between five decapeptides (both acyclic and cyclic), namely C-Asp, C-Asn, O-Asp, ODPro-Asp, and O-Asn, and the Aß(1-16) and Aß(1-40) fragments. Conformational constraints in such peptidic scaffolds affect their copper-binding affinity, which can be tuned. In the present study, the ability of these peptides to compete with Aß has been assessed in vitro, with the objective to examine whether such soft chelating agents may be used to lessen the deleterious interaction of Cu(II) with Aß. Fluorescence spectroscopy, electron paramagnetic resonance, and mass spectrometry data show that the more constrained peptide, i.e., cyclic C-Asp, which displays a Cu(II)-binding affinity comparable to that of Aß, is the only potential metal-protein attenuating compound (MPAC) candidate. In vitro aggregation studies with Aß(1-40) reveal that C-Asp can hamper the formation of copper-stabilized oligomeric Aß species, through capturing the metal ion prior to its interaction with monomeric Aß. The present study shows that (cyclic) peptides, preorganized for Cu(II) binding, may be applied for the development of potential copper-Aß attenuating compounds.


Assuntos
Peptídeos beta-Amiloides/antagonistas & inibidores , Cobre/química , Peptídeos Cíclicos/farmacologia , Peptídeos beta-Amiloides/química , Cinética , Modelos Moleculares , Estrutura Molecular , Peptídeos Cíclicos/química , Agregados Proteicos/efeitos dos fármacos
9.
Eur J Med Chem ; 187: 111961, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31865017

RESUMO

Accumulation of tau protein aggregation plays a crucial role in neurodegenerative diseases, such as Alzheimer's disease (AD). Uncontrollable neuroinflammation and tau pathology form a vicious circle that further aggravates AD progression. Herein, we reported the synthesis of usnic acid derivatives and evaluation of their inhibitory activities against tau-aggregation and neuroinflammation. The inhibitory activity of the derivatives against the self-fibrillation of the hexapeptide AcPHF6 was initially screened by ThT fluorescence assay. Using circular dichroism and transmission electron microscopy, compound 30 showed the most potent inhibitory activity against AcPHF6 self-fibrillation. Compound 30 was further confirmed to inhibit the aggregation of full-length 2N4R tau protein by a heparin-induced mechanism. In addition, we investigated the anti-inflammatory activity of compound 30, and showed that compared with sodium usnate, it reduced NO release in LPS-stimulated mouse microglia BV2 cells. More importantly, 30 showed significant protective effects against okadaic acid-induced memory impairment in rats. Thus, 30 was a novel tau-aggregation and neuroinflammation inhibitor that represented a potential therapeutic candidate for AD.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Benzofuranos/farmacologia , Inflamação/tratamento farmacológico , Aprendizagem em Labirinto/efeitos dos fármacos , Proteínas tau/antagonistas & inibidores , Doença de Alzheimer/metabolismo , Animais , Benzofuranos/síntese química , Benzofuranos/química , Linhagem Celular Tumoral , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Humanos , Inflamação/metabolismo , Lipopolissacarídeos/antagonistas & inibidores , Lipopolissacarídeos/farmacologia , Masculino , Camundongos , Modelos Moleculares , Estrutura Molecular , Óxido Nítrico/antagonistas & inibidores , Óxido Nítrico/biossíntese , Agregados Proteicos/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Relação Estrutura-Atividade , Proteínas tau/metabolismo
10.
J Enzyme Inhib Med Chem ; 35(1): 330-343, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31856607

RESUMO

Cholinesterase inhibitor plays an important role in the treatment of patients with Alzheimer's disease (AD). Herein, we report the medicinal chemistry efforts leading to a new series of 1,3-dimethylbenzimidazolinone derivatives. Among the synthesised compounds, 15b and 15j showed submicromolar IC50 values (15b, eeAChE IC50 = 0.39 ± 0.11 µM; 15j, eqBChE IC50 = 0.16 ± 0.04 µM) towards acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Kinetic and molecular modelling studies revealed that 15b and 15j act in a competitive manner. 15b and 15j showed neuroprotective effect against H2O2-induced oxidative damage on PC12 cells. This effect was further supported by their antioxidant activity determined in a DPPH assay in vitro. Morris water maze test confirmed the memory amelioration effect of the two compounds in a scopolamine-induced mouse model. Moreover, the hepatotoxicity of 15b and 15j was lower than tacrine. In summary, these data suggest 15b and 15j are promising multifunctional agents against AD.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Antioxidantes/farmacologia , Benzimidazóis/farmacologia , Inibidores da Colinesterase/farmacologia , Desenho de Drogas , Acetilcolinesterase/metabolismo , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/antagonistas & inibidores , Peptídeos beta-Amiloides/metabolismo , Animais , Antioxidantes/síntese química , Antioxidantes/química , Benzimidazóis/síntese química , Benzimidazóis/química , Butirilcolinesterase/metabolismo , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Inibidores da Colinesterase/síntese química , Inibidores da Colinesterase/química , Relação Dose-Resposta a Droga , Electrophorus , Células Hep G2 , Cavalos , Humanos , Camundongos , Camundongos Endogâmicos ICR , Modelos Moleculares , Estrutura Molecular , Células PC12 , Fragmentos de Peptídeos/antagonistas & inibidores , Fragmentos de Peptídeos/metabolismo , Agregados Proteicos/efeitos dos fármacos , Ratos , Relação Estrutura-Atividade
11.
Phys Chem Chem Phys ; 21(44): 24269-24285, 2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31670327

RESUMO

An enormous population worldwide is presently confronted with debilitating neurodegenerative diseases. The etiology of the disease is connected to protein aggregation and the events involved therein. Thus, a complete understanding of an inhibitor at different stages in the process is imperative for the formulation of a drug molecule. This review presents a detailed summary of the current status of different cosolvents. It further develops how the complex aggregation pathway can be simplified into three steps common to all proteins and the way computer simulations can be exploited to gain insights into the ways by which known inhibitors can affect all these stages. Computation of theoretical parameters in this regard and their correlation with experimental techniques is accentuated. In addition to providing an outline of the scope of different additives, this review showcases the way by which the problem of analyzing an effect of an additive can be addressed effectively via MD simulations.


Assuntos
Proteínas/química , Antioxidantes/química , Antioxidantes/farmacologia , Desenho de Drogas , Humanos , Simulação de Dinâmica Molecular , Monossacarídeos/química , Monossacarídeos/farmacologia , Doenças Neurodegenerativas/metabolismo , Doenças Neurodegenerativas/patologia , Agregados Proteicos/efeitos dos fármacos , Proteínas/metabolismo
12.
Pharm Res ; 36(12): 184, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31748894

RESUMO

PURPOSE: There is a plethora of studies on recombinant human bone morphogenetic protein-2 (rhBMP-2) application and delivery systems, but surprisingly few reports address the biophysical properties of the protein which are of crucial importance to develop effective delivery systems or to solve general problems related to rhBMP-2 production, purification, analysis and application. METHODS: The solubility, stability and bioactivity of rhBMP-2 obtained by renaturation of E. coli derived inclusion bodies was assessed at different pH and in different buffer systems using (dynamic) light scattering and thermal shift assays as well as intrinsic fluorescence measurements and luciferase based bioassays. RESULTS: rhBMP-2 is poorly soluble at physiological pH and higher. The presence of divalent anions further decreases the solubility even under acidic conditions. Thermal stability analyses revealed that rhBMP-2 precipitates are more stable compared to the soluble protein. Moreover, correctly folded rhBMP-2 is also bioactive as precipitated protein and precipitates readily dissolve under appropriate buffer conditions. Once properly formed rhBMP-2 also retains biological activity after temporary exposure to high concentrations of chaotropic denaturants. However, care should be taken to discriminate bioactive rhBMP-2 precipitates from misfolded rhBMP-2 aggregates, e.g. resolvability in MES buffer (pH 5) and a discrete peak in thermoshift experiments are mandatory for correctly folded rhBMP-2. CONCLUSIONS: Our analysis revealed that E. coli derived rhBMP-2 precipitates are not only bioactive but are also more stable compared to the soluble dimeric molecules. Knowledge about these unusual properties will be helpful to design improved delivery systems requiring lower amounts of rhBMP-2 in clinical applications.


Assuntos
Proteína Morfogenética Óssea 2/química , Escherichia coli/química , Fator de Crescimento Transformador beta/química , Heparina/química , Humanos , Concentração de Íons de Hidrogênio , Concentração Osmolar , Oxalatos/química , Tamanho da Partícula , Agregados Proteicos/efeitos dos fármacos , Conformação Proteica , Dobramento de Proteína/efeitos dos fármacos , Estabilidade Proteica/efeitos dos fármacos , Proteínas Recombinantes/química , Cloreto de Sódio/química , Solubilidade/efeitos dos fármacos , Temperatura Ambiente
13.
Elife ; 82019 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-31610847

RESUMO

Alzheimer's disease (AD) is the most common neurodegenerative disease affecting the elderly worldwide. Mitochondrial dysfunction has been proposed as a key event in the etiology of AD. We have previously modeled amyloid-beta (Aß)-induced mitochondrial dysfunction in a transgenic Caenorhabditis elegans strain by expressing human Aß peptide specifically in neurons (GRU102). Here, we focus on the deeper metabolic changes associated with this Aß-induced mitochondrial dysfunction. Integrating metabolomics, transcriptomics and computational modeling, we identify alterations in Tricarboxylic Acid (TCA) cycle metabolism following even low-level Aß expression. In particular, GRU102 showed reduced activity of a rate-limiting TCA cycle enzyme, alpha-ketoglutarate dehydrogenase. These defects were associated with elevation of protein carbonyl content specifically in mitochondria. Importantly, metabolic failure occurred before any significant increase in global protein aggregate was detectable. Treatment with an anti-diabetes drug, Metformin, reversed Aß-induced metabolic defects, reduced protein aggregation and normalized lifespan of GRU102. Our results point to metabolic dysfunction as an early and causative event in Aß-induced pathology and a promising target for intervention.


Assuntos
Peptídeos beta-Amiloides/genética , Caenorhabditis elegans/metabolismo , Ciclo do Ácido Cítrico/genética , Mitocôndrias/metabolismo , Neurônios/metabolismo , Estresse Fisiológico/genética , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Animais , Animais Geneticamente Modificados , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/genética , Ciclo do Ácido Cítrico/efeitos dos fármacos , Modelos Animais de Doenças , Humanos , Hipoglicemiantes/farmacologia , Complexo Cetoglutarato Desidrogenase/genética , Complexo Cetoglutarato Desidrogenase/metabolismo , Análise do Fluxo Metabólico , Metformina/farmacologia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/genética , Neurônios/efeitos dos fármacos , Neurônios/patologia , Agregados Proteicos/efeitos dos fármacos , Carbonilação Proteica , Estresse Fisiológico/efeitos dos fármacos
14.
J Biochem Mol Toxicol ; 33(11): e22395, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31583774

RESUMO

Raloxifene, a selective estrogen receptor modulator, displays benefits for Alzheimer's disease (AD) prevention in postmenopausal women as hormonal changes during menopause have the potential to influence AD pathogenesis, but the underlying mechanism of its neuroprotection is not entirely clear. In this study, the effects of raloxifene on amyloid-ß (Aß) amyloidogenesis were evaluated. The results demonstrated that raloxifene inhibits Aß42 aggregation and destabilizes preformed Aß42 fibrils through directly interacting with the N-terminus and middle domains of Aß42 peptides. Consequently, raloxifene not only reduces direct toxicity of Aß42 in HT22 neuronal cells, but also suppresses expressions of tumor necrosis factor-α and transforming growth factor-ß induced by Aß42 peptides, and then alleviates microglia-mediated indirect toxicity of Aß42 to HT22 neuronal cells. Our results suggested an alternative possible explanation for the neuroprotective activity of raloxifene in AD prevention.


Assuntos
Peptídeos beta-Amiloides/toxicidade , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Fragmentos de Peptídeos/toxicidade , Agregados Proteicos/efeitos dos fármacos , Cloridrato de Raloxifeno/farmacologia , Doença de Alzheimer/prevenção & controle , Peptídeos beta-Amiloides/química , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Expressão Gênica/efeitos dos fármacos , Interações Hidrofóbicas e Hidrofílicas , Camundongos , Microglia/citologia , Microglia/metabolismo , Neurônios/metabolismo , Fármacos Neuroprotetores/química , Fragmentos de Peptídeos/química , Agregação Patológica de Proteínas/metabolismo , Domínios Proteicos , Cloridrato de Raloxifeno/química , Fator de Crescimento Transformador beta/genética , Fator de Necrose Tumoral alfa/genética
15.
Eur J Pharm Biopharm ; 144: 207-216, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31521717

RESUMO

Reducing the aggregation of proteins is of utmost interest to the pharmaceutical industry. Aggregated proteins are often less active and can cause severe immune reactions in the patient upon administration. At the same time the biopharmaceutical market is pushing for high concentration formulations and products that do not require refrigerated storage conditions. For a given protein, the only solution pH, ionic strength and concentration of a very limited number of excipients are the only parameters that can be varied to obtain a stable formulation. In this work, we present a structure-based approach to discover new molecules that successfully reduce the aggregation of proteins and apply the approach to the model protein Interferon-alpha-2a.


Assuntos
Preparações Farmacêuticas/química , Agregados Proteicos/efeitos dos fármacos , Proteínas/química , Excipientes/química , Concentração de Íons de Hidrogênio , Interferon-alfa/química , Concentração Osmolar
16.
J Enzyme Inhib Med Chem ; 34(1): 1711-1715, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31547734

RESUMO

α-Synuclein (α-syn), a disordered cytoplasmatic protein, plays a fundamental role in the pathogenesis of Parkinson's disease (PD). Here, we have shown, using photophysical measurements, that addition of FKBP12 to α-syn solutions, dramatically accelerates protein aggregation, leading to an explosion of dendritic structures revealed by fluorescence and phase-contrast microscopy. We have further demonstrated that this aberrant α-syn aggregation can be blocked using a recently discovered non-immunosuppressive synthetic inhibitor of FKBP12, ElteN378. The role of FKBP12 and of ElteN378 in the α-syn aggregation mechanism has been elucidated using molecular dynamics simulations based on an effective coarse-grained model. The reported data not only reveal a new potent synthetic drug as a candidate for early stage treatment of α-syn dependent neurodegenerations but also pave the way to a deeper understanding of the mechanism of action of FKBP12 on α-syn oligomeric aggregation, a topic which is still controversial.


Assuntos
Piperidinas/farmacologia , Agregados Proteicos/efeitos dos fármacos , Proteína 1A de Ligação a Tacrolimo/antagonistas & inibidores , alfa-Sinucleína/química , Dendrímeros/química , Cinética , Simulação de Dinâmica Molecular , Piperidinas/química , Ligação Proteica , Conformação Proteica , Transdução de Sinais , Proteína 1A de Ligação a Tacrolimo/química , Proteína 1A de Ligação a Tacrolimo/metabolismo
17.
J Chem Theory Comput ; 15(10): 5169-5174, 2019 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-31476124

RESUMO

Aggregation of amyloid-ß (Aß) peptides is a crucial step in the progression of Alzheimer's disease (AD). Identifying aggregation inhibitors against AD has been a great challenge. We report an atomistic simulation study of the inhibition mechanism of two small molecules, homotaurine and scyllo-inositol, which are AD drug candidates currently under investigation. We show that both small molecules promote a conformational change of the Aß42 monomer toward a more collapsed phase through a nonspecific binding mechanism. This finding provides atomistic-level insights into designing potential drug candidates for future AD treatments.


Assuntos
Peptídeos beta-Amiloides/antagonistas & inibidores , Bibliotecas de Moléculas Pequenas/farmacologia , Peptídeos beta-Amiloides/química , Sítios de Ligação/efeitos dos fármacos , Humanos , Simulação de Dinâmica Molecular , Agregados Proteicos/efeitos dos fármacos , Ligação Proteica , Conformação Proteica/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/química
18.
J Biochem ; 166(6): 463-474, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31385584

RESUMO

Parkinsonism-linked mutations in alanine and glutamic acid residues of the pre-synaptic protein α-Synuclein (α-Syn) affect specific tertiary interactions essential for stability of the native state and make it prone to more aggregation. Many of the currently available drugs used for the treatment of Parkinson's disease (PD) are not very effective and are associated with multiple side effects. Recently, marine algae have been reported to have sulphated polysaccharides which offers multiple pharmaceutical properties. With this background, we have isolated sulphated polysaccharides from Chlamydomonas reinhardtii (Cr-SPs) and investigated their effects on inhibition of fibrillation/aggregation of α-Syn mutants through a combination of spectroscopic and microscopic techniques. The kinetics of α-Syn fibrillation establishes that Cr-SPs are very effective in inhibiting fibrillation of α-Syn mutants. The morphological changes associated with the fibrillation/aggregation process have been monitored by transmission electron microscopy. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis gel image suggests that Cr-SPs increase the amount of soluble protein after completion of the fibrillation/aggregation process. The circular dichroism results showed that Cr-SPs efficiently delay the conversion of native protein into ß-sheet-rich structures. Thus, the current work has considerable therapeutic implications towards deciphering the potential of Cr-SPs to act against PD and other protein aggregation-related disorders.


Assuntos
Chlamydomonas reinhardtii/química , Fármacos Neuroprotetores/farmacologia , Doença de Parkinson/tratamento farmacológico , Polissacarídeos/farmacologia , alfa-Sinucleína/antagonistas & inibidores , Humanos , Mutação , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/isolamento & purificação , Doença de Parkinson/metabolismo , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Agregados Proteicos/efeitos dos fármacos , alfa-Sinucleína/genética , alfa-Sinucleína/metabolismo
19.
Molecules ; 24(16)2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31416122

RESUMO

Accumulation of α-synuclein (α-Syn) is a remarkable pathology for Parkinson's disease (PD), therefore clearing it is possibly a promising strategy for treating PD. Aberrant copper (Cu(II)) homeostasis and oxidative stress play critical roles in the abnormal aggregation of α-Syn in the progress of PD. It is reported that the polyphenol (-)-epi-gallocatechin gallate (EGCG) can inhibit α-Syn fibrillation and aggregation, disaggregate α-Syn mature fibrils, as well as protect α-Syn overexpressed-PC12 cells against damage. Also, previous studies have reported that EGCG can chelate many divalent metal ions. What we investigate here is whether EGCG can interfere with the Cu(II) induced fibrillation of α-Syn and protect the cell viability. In this work, on a molecular and cellulaire basis, we demonstrated that EGCG can form a Cu(II)/EGCG complex, leading to the inhibition of Cu(II)-induced conformation transition of α-Syn from random coil to ß-sheet, which is a dominant structure in α-Syn fibrils and aggregates. Moreover, we found that the mixture of Cu(II) and EGCG in a molar ratio from 0.5 to 2 can efficiently inhibit this process. Furthermore, we demonstrated that in the α-Syn transduced-PC12 cells, EGCG can inhibit the overexpression and fibrillation of α-Syn in the cells, and reduce Cu(II)-induced reactive oxygen species (ROS), protecting the cells against Cu(II)-mediated toxicity.


Assuntos
Proteínas Amiloidogênicas/metabolismo , Catequina/análogos & derivados , Cobre , Agregados Proteicos/efeitos dos fármacos , Agregação Patológica de Proteínas/metabolismo , alfa-Sinucleína/metabolismo , Proteínas Amiloidogênicas/química , Animais , Catequina/química , Catequina/farmacologia , Linhagem Celular , Cobre/química , Cobre/toxicidade , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/farmacologia , Ressonância Magnética Nuclear Biomolecular , Estresse Oxidativo , Doença de Parkinson/tratamento farmacológico , Doença de Parkinson/metabolismo , Doença de Parkinson/patologia , Agregação Patológica de Proteínas/tratamento farmacológico , Ratos , Espécies Reativas de Oxigênio/metabolismo , alfa-Sinucleína/química
20.
Curr Pharm Biotechnol ; 20(12): 1028-1036, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31364512

RESUMO

BACKGROUND & OBJECTIVE: The present study was aimed at characterizing the conformational alterations induced in human transferrin, the iron regulatory protein by glyoxal. Since protein aggregation is at the core of many disorders, thus interest in this domain has increased significantly during the past years. METHODS: In our present study, the effect of glyoxal was monitored on human transferrin using multispectroscopic and multi-microscopic studies. RESULTS: Intrinsic fluorescence spectroscopy suggested changes in native conformation of human transferrin evident by decreased fluorescence and blue shift in the presence of glyoxal. Further, extrinsic fluorescence was retorted and the results showed the formation of aggregates; apparent by increased Congo red (CR) absorbance, Thioflavin T (ThT) and ANS fluorescence and TEM of human transferrin in the presence of glyoxal. Molecular docking was also employed to see which residues are at core of human transferrin and glyoxal interaction. Reactive oxygen species (ROS) generation assays revealed enhanced ROS levels by human transferrin after treatment with glyoxal. CONCLUSION: Thus, our study proposes that glyoxal induces the formation of aggregates in human transferrin. These aggregates further generate ROS which are key players in the complications associated with diabetes mellitus, giving our study clinical perspective.


Assuntos
Glioxal/química , Glioxal/farmacologia , Agregados Proteicos/efeitos dos fármacos , Transferrina/química , Células Cultivadas , Humanos , Linfócitos/efeitos dos fármacos , Linfócitos/metabolismo , Microscopia Eletrônica de Transmissão , Simulação de Acoplamento Molecular , Ligação Proteica , Espécies Reativas de Oxigênio , Espectrometria de Fluorescência
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA