RESUMEN
Aggregation of the protein α-Synuclein (αSyn) is a hallmark of Parkinson's disease (PD), dementia with Lewy bodies (DLB) and multiple systems atrophy, and alleviating the extent of αSyn pathology is an attractive strategy against neurodegeneration. The engineered binding protein ß-wrapin AS69 binds monomeric αSyn. AS69 reduces primary and secondary nucleation as well as fibril elongation in vitro. It also mitigates aSyn pathology in a mouse model based on intrastriatal injection of aSyn pre-formed fibrils (PFFs). Since the PFF-based model does not represent all aspects of PD, we tested here whether AS69 can reduce neurodegeneration resulting from αSyn overexpression. Human A53T-αSyn was overexpressed in the mouse Substantia nigra (SN) by using recombinant adeno-associated viral vector (rAAV). AS69 was also expressed by rAAV transduction. Behavioral tests and immunofluorescence staining were used as outcomes. Transduction with rAAV-αSyn resulted in αSyn pathology as reported by phospho-αSyn staining and caused degeneration of dopaminergic neurons in the SN. The co-expression of rAAV-AS69 did not reduce αSyn pathology or the degeneration of dopaminergic neurons. We conclude that αSyn monomer binding by rAAV-AS69 was insufficient to protect from aSyn pathology resulting from αSyn overexpression.
Asunto(s)
Modelos Animales de Enfermedad , Sustancia Negra , alfa-Sinucleína , Animales , alfa-Sinucleína/metabolismo , alfa-Sinucleína/genética , Ratones , Humanos , Sustancia Negra/metabolismo , Sustancia Negra/patología , Enfermedad de Parkinson/metabolismo , Enfermedad de Parkinson/genética , Enfermedad de Parkinson/patología , Dependovirus/genética , Neuronas Dopaminérgicas/metabolismo , Neuronas Dopaminérgicas/efectos de los fármacos , Masculino , Ratones Endogámicos C57BLRESUMEN
Alzheimer's disease is a neurodegenerative disorder for which there is a continuous search of drugs able to reduce or stop the cognitive decline. Beta-amyloid peptides are composed of 40 and 42 amino acids and are considered a major cause of neuronal toxicity. They are prone to aggregation, yielding oligomers and fibrils through the inter-molecular binding between the amino acid sequences (17-42) of multiple amyloid-beta molecules. Additionally, amyloid deposition causes cerebral amyloid angiopathy. The present study aims to identify, in the existing literature, natural plant derived products possessing inhibitory properties against aggregation. The studies searched proved the anti-aggregating effects by the thioflavin T assay and through behavioral, biochemical, and histological analysis carried out upon administration of natural chemical compounds to transgenic mouse models of Alzheimer's disease. According to our present study results, fifteen secondary metabolites from plants were identified which presented both evidence coming from the thioflavin T assay and transgenic mouse models developing Alzheimer's disease and six additional metabolites were mentioned due to their inhibitory effects against fibrillogenesis. Among them, epigallocatechin-3-gallate, luteolin, myricetin, and silibinin were proven to lower the aggregation to less than 40%.
Asunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Péptidos beta-Amiloides/antagonistas & inhibidores , Benzotiazoles/química , Productos Biológicos/farmacología , Colorantes Fluorescentes/química , Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/metabolismo , Animales , Productos Biológicos/química , Productos Biológicos/metabolismo , Catequina/análogos & derivados , Catequina/química , Catequina/metabolismo , Catequina/farmacología , Flavonoides/química , Flavonoides/metabolismo , Flavonoides/farmacología , Luteolina/química , Luteolina/metabolismo , Luteolina/farmacología , Ratones , Ratones Transgénicos , Agregado de Proteínas/efectos de los fármacos , Silibina/química , Silibina/metabolismo , Silibina/farmacologíaRESUMEN
Despite the controversial outcomes of clinical trials executed so far, the prevention of ß-amyloid (Aß) deposition and neurotoxicity by small molecule inhibitors of Aß aggregation remains a target intensively pursued in the search of effective drugs for treating Alzheimer's disease (AD) and related neurodegeneration syndromes. As a continuation of previous studies, a series of new 3-(2-arylhydrazono)indolin-2-one derivatives was synthesized and assayed, investigating the effects of substitutions on both the indole core and arylhydrazone moiety. Compared with the reference compound 1, we disclosed equipotent derivatives bearing alkyl substituents at the indole nitrogen, and fairly tolerated bioisosteric replacements at the arylhydrazone moiety. For most of the investigated compounds, the inhibition of Aß40 aggregation (expressed as pIC50) was found to be correlated with lipophilicity, as assessed by a reversed-phase HPLC method, through a bilinear relationship. The N¹-cyclopropyl derivative 28 was tested in cell-based assays of Aß42 oligomer toxicity and oxidative stress induced by hydrogen peroxide, showing significant cytoprotective effects. This study confirmed the versatility of isatin in preparing multitarget small molecules affecting different biochemical pathways involved in AD.
Asunto(s)
Péptidos beta-Amiloides/química , Péptidos beta-Amiloides/farmacología , Indoles/química , Indoles/farmacología , Neurotoxinas/toxicidad , Agregado de Proteínas , Línea Celular Tumoral , Citoprotección/efectos de los fármacos , Humanos , Cinética , Oxidación-Reducción , Relación Estructura-Actividad , Factores de TiempoRESUMEN
Alzheimer's disease (AD) is an incurable form of dementia affecting millions of people worldwide and costing billions of dollars in health care-related payments, making the discovery of a cure a top health, societal, and economic priority. Peptide-based drugs and immunotherapies targeting AD-associated beta-amyloid (Aß) aggregation have been extensively explored; however, their therapeutic potential is limited by unfavorable pharmacokinetic (PK) properties. Peptoids (N-substituted glycine oligomers) are a promising class of peptidomimetics with highly tunable secondary structures and enhanced stabilities and membrane permeabilities. In this review, the biological activities, structures, and physicochemical properties for several amyloid-targeting peptoids will be described. In addition, metal-chelating peptoids with the potential to treat AD will be discussed since there are connections between the dysregulation of certain metals and the amyloid pathway.
Asunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Quelantes , Sistemas de Liberación de Medicamentos/métodos , Peptoides , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/patología , Secuencias de Aminoácidos , Péptidos beta-Amiloides/antagonistas & inhibidores , Péptidos beta-Amiloides/metabolismo , Animales , Quelantes/química , Quelantes/uso terapéutico , Humanos , Peptoides/uso terapéuticoRESUMEN
A new series of pyridine derivatives with carbamic or amidic function has been designed and synthesized to act as cholinesterase inhibitors. The synthesized compounds were tested toward EeAChE and hAChE and toward eqBChE and hBChE. The carbamate 8 was the most potent hAChE inhibitor (IC50 = 0.153 ± 0.016 µM) while the carbamate 11 was the most potent inhibitor of hBChE (IC50 = 0.828 ± 0.067 µM). A molecular docking study indicated that the carbamate 8 was able to bind AChE by interacting with both CAS and PAS, in agreement with the mixed inhibition mechanism. Furthermore, the carbamates 8, 9 and 11 were able to inhibit Aß42 self-aggregation and possessed quite low toxicity against human astrocytoma T67 and HeLa cell lines, being the carbamate 8 the less toxic compound on both cell lines.
Asunto(s)
Acetilcolinesterasa/metabolismo , Péptidos beta-Amiloides/antagonistas & inhibidores , Butirilcolinesterasa/metabolismo , Inhibidores de la Colinesterasa/farmacología , Fragmentos de Péptidos/antagonistas & inhibidores , Piridinas/farmacología , Péptidos beta-Amiloides/metabolismo , Animales , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Inhibidores de la Colinesterasa/síntesis química , Inhibidores de la Colinesterasa/química , Relación Dosis-Respuesta a Droga , Anguilas , Caballos , Humanos , Modelos Moleculares , Estructura Molecular , Fragmentos de Péptidos/metabolismo , Agregado de Proteínas/efectos de los fármacos , Piridinas/síntesis química , Piridinas/química , Relación Estructura-ActividadRESUMEN
Amyloid or similar protein aggregates are the hallmarks of many disorders, including Alzheimer's, Parkinson's, Huntington's diseases and amyloidoses. The inhibition of the formation of these aberrant species by small molecules is a promising strategy for disease treatment. However, at present, all such diseases lack an appropriate therapeutic approach based on small molecules. In this work we have evaluated five bis(indolyl)phenylmethane derivatives to reduce amyloid fibril formation by hen egg white lysozyme (HEWL) and its associated cytotoxicity. HEWL is a widely used model system to study the fundamentals of amyloid fibril formation and is heterologous to human lysozyme, which forms amyloid fibrils in a familial form of systemic amyloidosis. HEWL aggregation was tested in the presence and absence of the five compounds, under conditions in which the protein is partially unfolded. To this purpose, various techniques were used, including Congo red and Thioflavin T binding assays, atomic force microscopy, Fourier-Transform Infrared spectroscopy and cell-based cytotoxicity assays, such as the MTT reduction test and the trypan blue test. It was found that all compounds inhibited the formation of amyloid fibrils and their associated toxicity, diverging the aggregation process towards the formation of large, morphologically amorphous, unstructured, nontoxic aggregates, thus resembling class I molecules defined previously. In addition, the five compounds also appeared to disaggregate pre-formed fibrils of HEWL, which categorizes them into class IA. The half maximal inhibitory concentration (IC50) was found to be ca 12.3 ± 1.0 µM for the forefather compound.
Asunto(s)
Amiloide/química , Indoles/química , Indoles/farmacología , Muramidasa/química , Agregado de Proteínas/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Humanos , Indoles/toxicidad , Cinética , Células MCF-7RESUMEN
Cholinesterases and amyloid beta are one of the major biological targets in the search for a new and efficacious treatment of Alzheimer's disease. The study describes synthesis and pharmacological evaluation of new compounds designed as dual binding site acetylcholinesterase inhibitors. Among the synthesized compounds, two deserve special attention--compounds 42 and 13. The former is a saccharin derivative and the most potent and selective acetylcholinesterase inhibitor (EeAChE IC50 = 70 nM). Isoindoline-1,3-dione derivative 13 displays balanced inhibitory potency against acetyl- and butyrylcholinesterase (BuChE) (EeAChE IC50 = 0.76 µM, EqBuChE IC50 = 0.618 µM), and it inhibits amyloid beta aggregation (35.8% at 10 µM). Kinetic studies show that the developed compounds act as mixed or non-competitive acetylcholinesterase inhibitors. According to molecular modelling studies, they are able to interact with both catalytic and peripheral active sites of the acetylcholinesterase. Their ability to cross the blood-brain barrier (BBB) was confirmed in vitro in the parallel artificial membrane permeability BBB assay. These compounds can be used as a solid starting point for further development of novel multifunctional ligands as potential anti-Alzheimer's agents.
Asunto(s)
Acetilcolinesterasa/uso terapéutico , Enfermedad de Alzheimer/tratamiento farmacológico , Péptidos beta-Amiloides/uso terapéutico , Inhibidores de la Colinesterasa/uso terapéutico , Agregación Patológica de Proteínas/tratamiento farmacológico , Acetilcolinesterasa/química , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides/síntesis química , Péptidos beta-Amiloides/química , Sitios de Unión , Barrera Hematoencefálica/efectos de los fármacos , Butirilcolinesterasa/química , Butirilcolinesterasa/uso terapéutico , Inhibidores de la Colinesterasa/síntesis química , Inhibidores de la Colinesterasa/química , Humanos , Isoindoles/síntesis química , Isoindoles/química , Isoindoles/uso terapéutico , Ligandos , Modelos Moleculares , Agregación Patológica de Proteínas/metabolismo , Relación Estructura-ActividadRESUMEN
Alzheimer's disease (AD) is a fatal and complex neurodegenerative disorder for which effective treatment remains the unmet challenge. Using donepezil as a starting point, we aimed to develop novel potential anti-AD agents with a multidirectional biological profile. We designed the target compounds as dual binding site acetylcholinesterase inhibitors, where the N-benzylamine pharmacophore is responsible for interactions with the catalytic anionic site of the enzyme. The heteroaromatic fragment responsible for interactions with the peripheral anionic site was modified and three different heterocycles were introduced: isoindoline, isoindolin-1-one, and saccharine. Based on the results of the pharmacological evaluation, we identified compound 8b with a saccharine moiety as the most potent and selective human acetylcholinesterase inhibitor (IC50 = 33 nM) and beta amyloid aggregation inhibitor. It acts as a non-competitive acetylcholinesterase inhibitor and is able to cross the blood-brain barrier in vitro. We believe that compound 8b represents an important lead compound for further development as potential anti-AD agent.
Asunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Péptidos beta-Amiloides/metabolismo , Bencilaminas/síntesis química , Bencilaminas/farmacología , Inhibidores de la Colinesterasa/síntesis química , Inhibidores de la Colinesterasa/farmacología , Diseño de Fármacos , Compuestos Heterocíclicos/síntesis química , Compuestos Heterocíclicos/farmacología , Fragmentos de Péptidos/metabolismo , Acetilcolinesterasa/química , Acetilcolinesterasa/metabolismo , Enfermedad de Alzheimer/diagnóstico , Enfermedad de Alzheimer/enzimología , Péptidos beta-Amiloides/química , Sitios de Unión , Unión Competitiva , Barrera Hematoencefálica/metabolismo , Butirilcolinesterasa/metabolismo , Permeabilidad Capilar , Dominio Catalítico , Inhibidores de la Colinesterasa/metabolismo , Proteínas Ligadas a GPI/antagonistas & inhibidores , Proteínas Ligadas a GPI/química , Proteínas Ligadas a GPI/metabolismo , Cinética , Ligandos , Simulación del Acoplamiento Molecular , Terapia Molecular Dirigida , Fragmentos de Péptidos/química , Agregación Patológica de Proteínas , Unión Proteica , Conformación Proteica , Sacarina/análogos & derivados , Sacarina/síntesis química , Sacarina/farmacología , Relación Estructura-ActividadRESUMEN
The presented study describes the synthesis, pharmacological evaluation (AChE and BuChE inhibition, beta amyloid anti-aggregation effect and neuroprotective effect), molecular modeling and crystallographic studies of a novel series of isoindoline-1,3-dione derivatives. The target compounds were designed as dual binding site acetylcholinesterase inhibitors with an arylalkylamine moiety binding at the catalytic site of the enzyme and connected via an alkyl chain to a heterocyclic fragment, capable of binding at the peripheral anionic site of AChE. Among these molecules, compound 15b was found to be the most potent and selective AChE inhibitor (IC50EeAChE = 0.034 µM). Moreover, compound 13b in addition to AChE inhibition (IC50 EeAChE = 0.219 µM) possesses additional properties, such as the ability to inhibit Aß aggregation (65.96% at 10 µM) and a neuroprotective effect against Aß toxicity at 1 and 3 µM. Compound 13b emerges as a promising multi-target ligand for the further development of the therapy for age-related neurodegenerative disorders.
Asunto(s)
Acetilcolinesterasa/metabolismo , Péptidos beta-Amiloides/antagonistas & inhibidores , Bencilaminas/farmacología , Inhibidores de la Colinesterasa/farmacología , Fármacos Neuroprotectores/farmacología , Ftalimidas/farmacología , Agregado de Proteínas/efectos de los fármacos , Agregación Patológica de Proteínas/tratamiento farmacológico , Péptidos beta-Amiloides/metabolismo , Bencilaminas/síntesis química , Bencilaminas/química , Línea Celular Tumoral , Inhibidores de la Colinesterasa/síntesis química , Inhibidores de la Colinesterasa/química , Relación Dosis-Respuesta a Droga , Humanos , Modelos Moleculares , Estructura Molecular , Fármacos Neuroprotectores/síntesis química , Fármacos Neuroprotectores/química , Ftalimidas/síntesis química , Ftalimidas/química , Relación Estructura-ActividadRESUMEN
In Alzheimer's disease (AD), native Aß protein monomers aggregate through the formation of a variety of water-soluble, toxic oligomers, ultimately leading to insoluble fibrillar deposits. The inhibition of oligomers formation and/or their dissociation into non-toxic monomers, are considered an attractive strategy for the prevention and treatment of AD. A number of studies have demonstrated that small molecules, containing single or multiple (hetero)aromatic rings, can inhibit protein aggregation, being potentially effective in AD treatment. Starting from previously reported data on the antiamyloidogenic activity of a series of 3-hydrazonoindolinones, compound PT2 was selected to deeply investigate the inhibitory mechanism in the Aß aggregation cascade. We compared data from DLS, NMR, CD, TEM and ThT fluorescence measures to ascertain the interactions with amyloidogenic species formed in vitro during the aggregation process, and confirmed this feature with cell viability tests on HeLa cultured cells. PT2 was effective in disrupting toxic oligomers and mature amyloid fibrils, stabilizing Aß as non-toxic, ß-sheet arranged, ThT-insensitive protofilaments. It also strongly reduced cellular toxicity caused by Aß and showed good antioxidant properties in two radical scavenging tests. Taken together, these data confirmed that PT2 is a small molecule inhibitor of Aß oligomerization and toxicity, displaying also additional activity as antioxidant.
Asunto(s)
Péptidos beta-Amiloides/química , Péptidos beta-Amiloides/toxicidad , Depuradores de Radicales Libres/farmacología , Indoles/farmacología , Fragmentos de Péptidos/química , Fragmentos de Péptidos/toxicidad , Multimerización de Proteína/efectos de los fármacos , Péptidos beta-Amiloides/metabolismo , Supervivencia Celular/efectos de los fármacos , Depuradores de Radicales Libres/metabolismo , Células HeLa , Humanos , Indoles/metabolismo , Cinética , Fragmentos de Péptidos/metabolismo , Estructura Secundaria de Proteína/efectos de los fármacosRESUMEN
Scientists working in the field of Alzheimer's disease and, in particular, cognitive enhancers, are very productive. The review "Drugs interacting with Targets other than Receptors or Enzymes. Disease-modifying Drugs" was accepted in October 2012. In the last 20 months, new targets for the potential treatment of Alzheimer's disease were identified. Enormous progress was realized in the pharmacological characterization of natural products with cognitive enhancing properties. This review covers the evolution of research in this field through May 2014.
Asunto(s)
Nootrópicos/farmacología , Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/fisiopatología , Animales , Humanos , Nootrópicos/química , Nootrópicos/uso terapéuticoRESUMEN
The anti-amyloid properties shared by several quinones inspired the design of a new series of hybrids derived from the multi-target drug candidate memoquin (1). The hybrids consist of a central benzoquinone core and a fragment taken from non-steroidal anti-inflammatory drugs, connected through polyamine linkers. The new hybrids retain the potent anti-aggregating activity of the parent 1, while exhibiting micromolar AChE inhibitory activities. Remarkably, 2, 4, (R)-6 and (S)-6 were Aß aggregation inhibitors even more potent than 1. The balanced amyloid/cholinesterase inhibitory profile is an added value that makes the present series of compounds promising leads against Alzheimer's disease.