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1.
Cell Mol Life Sci ; 77(2): 331-350, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31209506

RESUMO

Disintegrin and metalloproteinases (ADAMs) 10 and 17 can release the extracellular part of a variety of membrane-bound proteins via ectodomain shedding important for many biological functions. So far, substrate identification focused exclusively on membrane-anchored ADAM10 and ADAM17. However, besides known shedding of ADAM10, we identified ADAM8 as a protease capable of releasing the ADAM17 ectodomain. Therefore, we investigated whether the soluble ectodomains of ADAM10/17 (sADAM10/17) exhibit an altered substrate spectrum compared to their membrane-bound counterparts. A mass spectrometry-based N-terminomics approach identified 134 protein cleavage events in total and 45 common substrates for sADAM10/17 within the secretome of murine cardiomyocytes. Analysis of these cleavage sites confirmed previously identified amino acid preferences. Further in vitro studies verified fibronectin, cystatin C, sN-cadherin, PCPE-1 as well as sAPP as direct substrates of sADAM10 and/or sADAM17. Overall, we present the first degradome study for sADAM10/17, thereby introducing a new mode of proteolytic activity within the protease web.


Assuntos
Proteína ADAM10/metabolismo , Proteína ADAM17/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Proteínas de Membrana/metabolismo , Metaloproteases/metabolismo , Aminoácidos/metabolismo , Animais , Linhagem Celular , Células HEK293 , Humanos , Camundongos , Miócitos Cardíacos/metabolismo
2.
J Enzyme Inhib Med Chem ; 34(1): 712-727, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31852270

RESUMO

The design of multi-target directed ligands (MTDLs) is a valid approach for obtaining effective drugs for complex pathologies. MTDLs that combine neuro-repair properties and block the first steps of neurotoxic cascades could be the so long wanted remedies to treat neurodegenerative diseases (NDs). By linking two privileged scaffolds with well-known activities in ND-targets, the flavonoid and the N,N-dibenzyl(N-methyl)amine (DBMA) fragments, new CNS-permeable flavonoid - DBMA hybrids (1-13) were obtained. They were subjected to biological evaluation in a battery of targets involved in Alzheimer's disease (AD) and other NDs, namely human cholinesterases (hAChE/hBuChE), ß-secretase (hBACE-1), monoamine oxidases (hMAO-A/B), lipoxygenase-5 (hLOX-5) and sigma receptors (σ1R/σ2R). After a funnel-type screening, 6,7-dimethoxychromone - DBMA (6) was highlighted due to its neurogenic properties and an interesting MTD-profile in hAChE, hLOX-5, hBACE-1 and σ1R. Molecular dynamic simulations showed the most relevant drug-protein interactions of hybrid 6, which could synergistically contribute to neuronal regeneration and block neurodegeneration.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Inibidores Enzimáticos/farmacologia , Flavonoides/farmacologia , Metilaminas/farmacologia , Regeneração Nervosa/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Acetilcolinesterase/metabolismo , Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Araquidonato 5-Lipoxigenase/metabolismo , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Ácido Aspártico Endopeptidases/metabolismo , Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/metabolismo , Butirilcolinesterase/metabolismo , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Flavonoides/química , Humanos , Masculino , Metilaminas/química , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Modelos Moleculares , Estrutura Molecular , Monoaminoxidase/metabolismo , Fármacos Neuroprotetores/síntese química , Fármacos Neuroprotetores/química
3.
EMBO J ; 38(23): e102345, 2019 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-31701556

RESUMO

In Alzheimer's disease, BACE1 protease initiates the amyloidogenic processing of amyloid precursor protein (APP) that eventually results in synthesis of ß-amyloid (Aß) peptide. Aß deposition in turn causes accumulation of BACE1 in plaque-associated dystrophic neurites, thereby potentiating progressive Aß deposition once initiated. Since systemic pharmacological BACE inhibition causes adverse effects in humans, it is important to identify strategies that specifically normalize overt BACE1 activity around plaques. The microtubule-associated protein tau regulates axonal transport of proteins, and tau deletion rescues Aß-induced transport deficits in vitro. In the current study, long-term in vivo two-photon microscopy and immunohistochemistry were performed in tau-deficient APPPS1 mice. Tau deletion reduced plaque-associated axonal pathology and BACE1 accumulation without affecting physiological BACE1 expression distant from plaques. Thereby, tau deletion effectively decelerated formation of new plaques and reduced plaque compactness. The data revealed that tau reinforces Aß deposition, presumably by contributing to accumulation of BACE1 in plaque-associated dystrophies. Targeting tau-dependent mechanisms could become a suitable strategy to specifically reduce overt BACE1 activity around plaques, thereby avoiding adverse effects of systemic BACE inhibition.


Assuntos
Doença de Alzheimer/prevenção & controle , Secretases da Proteína Precursora do Amiloide/fisiologia , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Regulação da Expressão Gênica , Placa Amiloide/prevenção & controle , Proteínas tau/antagonistas & inibidores , Doença de Alzheimer/etiologia , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Secretases da Proteína Precursora do Amiloide/genética , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Ácido Aspártico Endopeptidases/genética , Ácido Aspártico Endopeptidases/metabolismo , Encéfalo/metabolismo , Encéfalo/patologia , Modelos Animais de Doenças , Feminino , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Placa Amiloide/etiologia , Placa Amiloide/metabolismo , Placa Amiloide/patologia
4.
Expert Opin Investig Drugs ; 28(11): 967-975, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31661331

RESUMO

Introduction: The amyloid hypothesis of Alzheimer's disease (AD) states that brain accumulation of amyloid-ß (Aß) oligomers and soluble aggregates represents the major causal event of the disease. Several small organic molecules have been synthesized and developed to inhibit the enzyme (ß-site amyloid precursor protein cleaving enzyme-1 or BACE1) whose action represents the rate-limiting step in Aß production.Areas covered: We reviewed the pharmacology and clinical trials of major BACE1 inhibitors.Expert opinion: In transgenic mouse models of AD, BACE1 inhibitors dose-dependently lower Aß levels in brain and cerebrospinal fluid (CSF) but the evidence for attenuation or reversal cognitive or behavioral deficits is very scanty. In AD patients, BACE1 inhibitors robustly lower plasma and CSF Aß levels and reduce brain plaques but without cognitive, clinical, or functional benefit. To date, seventeen BACE1 inhibitors have failed in double-blind, placebo-controlled clinical trials in patients with mild-to-moderate or prodromal AD, or in cognitively normal subjects at risk of developing AD. Several of these studies were prematurely interrupted due to toxicity or cognitive and behavioral worsening compared to placebo-treated patients. Elenbecestat, the last BACE1 inhibitor remaining in late clinical testing for AD, was recently discontinued due to safety concerns.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Drogas em Investigação/administração & dosagem , Doença de Alzheimer/fisiopatologia , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/metabolismo , Animais , Ácido Aspártico Endopeptidases/metabolismo , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Desenvolvimento de Medicamentos , Drogas em Investigação/farmacologia , Humanos , Camundongos , Camundongos Transgênicos
5.
Eur J Med Chem ; 183: 111707, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31561043

RESUMO

The diverse nature of Alzheimer's disease (AD) has prompted researchers to develop multi-functional agents. Herein, we have designed and synthesized molecular hybrids of 2-pyridylpiperazine and 5-phenyl-1,3,4-oxadiazoles. Biological activities of synthesized compounds suggested significant and balanced inhibitory potential against target enzymes. In particular, compound 49 containing 2,4-difluoro substitution at terminal phenyl ring considered as most potential lead with inhibition of acetylcholinesterase (hAChE, IC50 = 0.054 µM), butyrylcholinesterase (hBChE, IC50 = 0.787 µM) and beta-secretase-1 (hBACE-1, IC50 = 0.098 µM). The enzyme kinetics study of 49 against hAChE suggested a mixed type of inhibition (Ki = 0.030 µM). Also, 48 and 49 showed significant displacement of propidium iodide from the peripheral anionic site (PAS) of hAChE, excellent blood-brain barrier (BBB) permeability in parallel artificial membrane permeation assay (PAMPA), and neuroprotective ability against SH-SY5Y neuroblastoma cell lines. Further, 49 also exhibited anti-Aß aggregation activity in self- and AChE-induced thioflavin T assay, which was ascertained by morphological characterization by atomic force microscopy (AFM). Moreover, in vivo behavioral studies signified learning and memory improvement by compound 49 in scopolamine- and Aß-induced cognitive dysfunctions performed on Y-maze and Morris water maze. The ex vivo studies suggested decreased AChE activity and antioxidant potential of compound 49, with good oral absorption characteristics ascertained by pharmacokinetic studies.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Fármacos Neuroprotetores/química , Oxidiazóis/química , Piperazinas/química , Piridinas/química , Acetilcolinesterase/metabolismo , Doença de Alzheimer/psicologia , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Antioxidantes/química , Antioxidantes/farmacologia , Barreira Hematoencefálica/metabolismo , Butirilcolinesterase/metabolismo , Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacocinética , Disfunção Cognitiva/tratamento farmacológico , Feminino , Humanos , Cinética , Simulação de Acoplamento Molecular , Fármacos Neuroprotetores/farmacocinética , Oxidiazóis/farmacocinética , Piperazinas/farmacocinética , Agregados Proteicos , Piridinas/farmacocinética , Ratos Wistar , Relação Estrutura-Atividade
6.
Chem Biodivers ; 16(11): e1900370, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31523926

RESUMO

A novel series of phthalimide-dithiocarbamate hybrids was synthesized and evaluated for in vitro inhibitory potentials against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). The anti-cholinesterase results indicated that among the synthesized compounds, the compounds 7g and 7h showed the most potent anti-AChE and anti-BuChE activities, respectively. Molecular docking and dynamic studies of the compounds 7g and 7h, respectively, in the active site of AChE and BuChE revealed that these compounds as well interacted with studied cholinesterases. These compounds also possessed drug-like properties and were able to cross the BBB.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Desenho de Drogas , Inibidores Enzimáticos/farmacologia , Simulação de Acoplamento Molecular , Ftalimidas/farmacologia , Tiocarbamatos/farmacologia , Acetilcolinesterase/metabolismo , Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Ácido Aspártico Endopeptidases/metabolismo , Butirilcolinesterase/metabolismo , Electrophorus , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Cavalos , Humanos , Simulação de Dinâmica Molecular , Estrutura Molecular , Ftalimidas/química , Tiocarbamatos/química
7.
Eur J Med Chem ; 180: 690-706, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31401465

RESUMO

In this review, we present the latest advances in the field of multi-target-directed ligand (MTDL) design for the treatment of various complex pathologies of multifactorial origin. In particular, latest findings in the field of MTDL design targeting both an enzyme and a receptor are presented for different diseases such as Alzheimer's disease (AD), depression, addiction, glaucoma, non-alcoholic steatohepatitis and pain and inflammation. The ethology of the diseases is briefly described, with special emphasis on how the MTDL can evolve into novel therapies that replace the classic pharmacological dogma "one target one disease". Considering the current needs for therapy adherence improvement, it is exposed as from the medicinal chemistry, different molecular scaffolds are studied. With the use of structure activity relationship studies and molecular optimization, new hybrid molecules are generated with improved biological properties acting at two biologically very distinct targets.


Assuntos
Inibidores Enzimáticos/farmacologia , Acetilcolinesterase/metabolismo , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Butirilcolinesterase/metabolismo , Desenho de Drogas , Inibidores Enzimáticos/química , Humanos , Ligantes , Receptores de Canabinoides/metabolismo , Receptores Histamínicos/metabolismo
8.
Cell Physiol Biochem ; 53(2): 413-428, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31415717

RESUMO

BACKGROUND/AIMS: Amyloid plaques, generated during the progression of Alzheimer's disease, cause major neurological deficits due to substantial cell toxicity and death. The underlying cause of plaque generation stems from cleavage of the amyloid precursor protein (APP) by ß-secretase (BACE1). A resulting amyloid-ß (Aß) fragment forms aggregates to produce the main constituent of a plaque. METHODS: Phage display and biopanning techniques were used to identify a 12-mer peptide that had a natural affinity for the BACE1 enzyme. The peptide was translated from phage DNA and synthetically produced. The peptide, at concentrations of 1nM, 10nM and 100nM, was used to confirm binding by direct assay. Non-specific binding to BACE2, renin and cathepsin D was tested by direct binding assay. A BACE1 activity assay was used to determine the peptide effect on cleavage of an APP substrate. Treatment of SY5Y cells with the peptide was used to determine toxicity and prevention of Aß40 and Aß42 production. RESULTS: After identification and synthetic production, the peptide exhibited a strong affinity for BACE1 at nanomolar concentrations in the direct assay. In case of non-specific binding to homologous BACE2, renin and cathepsin D, the peptide showed minor binding but was nullified when in solution with BACE1. The peptide addition to a BACE1 activity assay was able to significantly reduce the amount of substrate cleavage. SY5Y cells, when treated with the peptide, did not show any detrimental morphological changes while being able to reduce the production of natural Aß40 and Aß42. Even under stressed conditions (H2O2 treatment) where the Aß production was higher, the peptide was still able to significantly reduce the effect of BACE1 while not effecting cell viability. CONCLUSION: The identified peptide exhibited strong binding to BACE1 in vitro and was able to reduce production of Aß, suggesting a favourable BACE1 inhibitor for future refining and characterisation.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Peptídeos beta-Amiloides/antagonistas & inibidores , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Fragmentos de Peptídeos/antagonistas & inibidores , Peptídeos/farmacologia , Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Linhagem Celular , Descoberta de Drogas , Inibidores Enzimáticos/metabolismo , Humanos , Fragmentos de Peptídeos/metabolismo , Peptídeos/metabolismo
9.
Nat Commun ; 10(1): 3442, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31371707

RESUMO

The presence of amyloid beta (Aß) plaques in the brain of some individuals with Creutzfeldt-Jakob or Gertsmann-Straussler-Scheinker diseases suggests that pathogenic prions (PrPSc) would have stimulated the production and deposition of Aß peptides. We here show in prion-infected neurons and mice that deregulation of the PDK1-TACE α-secretase pathway reduces the Amyloid Precursor Protein (APP) α-cleavage in favor of APP ß-processing, leading to Aß40/42 accumulation. Aß predominates as monomers, but is also found as trimers and tetramers. Prion-induced Aß peptides do not affect prion replication and infectivity, but display seedable properties as they can deposit in the mouse brain only when seeds of Aß trimers are co-transmitted with PrPSc. Importantly, brain Aß deposition accelerates death of prion-infected mice. Our data stress that PrPSc, through deregulation of the PDK1-TACE-APP pathway, provokes the accumulation of Aß, a prerequisite for the onset of an Aß seeds-induced Aß pathology within a prion-infectious context.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Doenças Priônicas/metabolismo , Príons/metabolismo , /metabolismo , Proteína ADAM17/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Comportamento Animal , Encéfalo/metabolismo , Modelos Animais de Doenças , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Doenças Neurodegenerativas/metabolismo , Neurônios/metabolismo , Fragmentos de Peptídeos/líquido cefalorraquidiano , Placa Amiloide/metabolismo , Doenças Priônicas/líquido cefalorraquidiano , Doenças Priônicas/patologia , Células-Tronco
10.
Expert Opin Pharmacother ; 20(17): 2095-2099, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31423903

RESUMO

Introduction: The amyloid-beta (Aß) cascade hypothesis is that reducing Aß levels in the brain will be beneficial in treating Alzheimer's disease. Aß is formed by the cleavage of amyloid precursor protein by ß-site amyloid precure protein cleaving enzyme (BACE1) and the BACE1 inhibitor verubecestat was developed to lower the brain levels of Aß. However, in the EPOCH trial of verubecestat in mild-to-moderate Alzheimer's disease, it was not beneficial and increased adverse effects.Areas covered: Prior to completing EPOCH, APECS, which trialled verubecestat in prodromal Alzheimer's disease, was commenced. Like EPOCH, APECS was terminated early. In APECS, verubecestat 40 mg worsened cognition and increased adverse effects.Expert opinion: In recruiting subjects to clinical trials in Alzheimer's disease, a clinical diagnosis involving the measurement of Aß should be undertaken for all subjects, as this may help to clarify the findings. In my opinion, the failure of verubecestat in EPOCH and APECS probably could have been avoided if a safety and potential efficacy trial (phase 2) had been completed prior to starting phase 3. It seems to me that, as we have a poor understanding of the underlying mechanisms/cause of Alzheimer's disease, this is where the research emphasis should be, not phase 3 clinical trials.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Óxidos S-Cíclicos/uso terapêutico , Tiadiazinas/uso terapêutico , Doença de Alzheimer/patologia , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Peptídeos beta-Amiloides/metabolismo , Encéfalo/metabolismo , Óxidos S-Cíclicos/efeitos adversos , Depressão/etiologia , Dermatite/etiologia , Humanos , Índice de Gravidade de Doença , Tiadiazinas/efeitos adversos , Falha de Tratamento
11.
Life Sci ; 234: 116783, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31442552

RESUMO

Breast cancer (BCa) is the most commonly diagnosed lethal cancer in women worldwide. Notch signaling pathway is directly linked to BCa recurrence and aggressiveness. Natural remedies are becoming a prime choice to overcome against cancer due to lesser side effect and cost-effectiveness. Bulbine frutescens (Asphodelaceae), a traditional medicinal plant in South Africa possess bioactive flavonoids and terpenoids. Polar (methanol) and non-polar (hexane) B. frutescens plant extracts were prepared. GC-MS analysis revealed the differential presence of secondary metabolites in both methanolic and hexane extracts. We hereby first time evaluated the anticancer potential of B. frutescens methanolic and hexane extract in triple-negative and luminal BCa cells. B. frutescens extracts significantly decreased cell viability (IC50 4.8-28.4 µg/ml) and induced cell cycle arrest at G1 phase in MDA-MB-231 and T47D cells as confirmed by spectrophotometry and flow cytometry technique. RT-PCR analysis of cell cycle (cyclin D1, CDK4, and p21) and apoptosis modulating genes (caspase 3, Bcl2 and survivin) revealed upexpression of p21, and caspase 3, and down expression of cyclin D1, CDK4, Bcl2 and survivin genes in extract-treated BCa cells. Fluorescence spectrophotometry and confocal microscopy showed B. frutescens induced nuclear morphology and mitochondrial integrity disruption, and increased reactive oxygen species production in MDA-MB-231 and T47D cells. Flow cytometric apoptosis analysis of B. frutescens extracts treated MDA-MB-231 cells showed ≈13% increase in early apoptotic population in comparison to non-treated cells. Dual-Luciferase Reporter assay confirmed notch promoter inhibitory activity of B. frutescens extracts. Moreover, RTPCR analysis showed down regulation of notch responsive genes (Hes1 and Hey1) at transcription levels in extract-treated BCa cells. Western Blot analysis showed increased procaspase 3 protein expression in extract-treated BCa cells. In all the assays methanolic extract showed better anti-cancer properties. Literature-based identification of methanol soluble phytochemicals in B. frutescens and in silico docking study revealed Bulbineloneside D as a potent ϒ-secretase enzyme inhibitor. In comparison to standard notch inhibitor, lead phytochemical showed two additional hydrophobic interactions with Ala80 and Leu81 amino acids. In conclusion, B. frutescens phytochemicals have cell cycle arrest, ROS production, apoptosis induction, and mitochondria membrane potential disruption efficacy in breast cancer cells. B. frutescens phytochemicals have the ability to downregulate the notch signaling pathway in triple-negative and luminal breast cancer cells.


Assuntos
Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias da Mama/tratamento farmacológico , Receptores Notch/metabolismo , Transdução de Sinais/efeitos dos fármacos , Xanthorrhoeaceae/química , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Secretases da Proteína Precursora do Amiloide/metabolismo , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Feminino , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/patologia
12.
Comput Biol Chem ; 83: 107101, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31442708

RESUMO

Lupane-type triterpenoids have shown a potential effect against neurodegenerative disorders. Alzheimer's disease, one of the common neurodegenerative disease, is evident by the accumulation of amyloid-beta (Aß) plaque in the extracellular regions of the brain. ß-site amyloid precursor protein cleaving enzyme 1 (BACE1) is a key enzyme for the Aß formation viathe cleavage of amyloid precursor protein (APP). Therefore, to find the potent BACE1 inhibitors and furthermore to explore the role of the functional group responsible for the strong BACE1 inhibitory activity, we synthesized a series of triterpenoids with lupane skeleton starting from the natural compounds calenduladiol and lupeol. Compound 1 revealed a potent competitive BACE1 inhibitory activity (IC50 = 16.77 ±â€¯1.16 µM; Ki = 19.38). Furthermore, the molecular docking simulation revealed the importance of Tyr198 residue along with the other hydrophobic interactions for the strong affinity of 1‒BACE1 complex. To sum up, our results demonstrated the importance of carbonyl moiety at 3 and 16 position of lupane-type triterpenoid over the hydroxyl group at the same position.


Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Triterpenos/farmacologia , Secretases da Proteína Precursora do Amiloide/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Cristalografia por Raios X , Inibidores Enzimáticos/química , Humanos , Cinética , Modelos Moleculares , Triterpenos/química
13.
Cancer Sci ; 110(9): 2941-2959, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31343810

RESUMO

A sensitive and specific diagnosis biomarker, in principle scalable to most cancer types, is needed to reduce the prevalent cancer mortality. Meanwhile, the investigation of diagnosis determinants of a biomarker will facilitate the interpretation of its screening results in clinic. Here we design a large-scale (1558 enrollments), multicenter (multiple hospitals), and cross-validation (two datasets) clinic study to validate plasma Hsp90α quantified by ELISA as a pan-cancer biomarker. ROC curve shows the optimum diagnostic cutoff is 69.19 ng/mL in discriminating various cancer patients from all controls (AUC 0.895, sensitivity 81.33% and specificity 81.65% in test cohort; AUC 0.893, sensitivity 81.72% and specificity 81.03% in validation cohort). Similar results are noted in detecting early-stage cancer patients. Plasma Hsp90α maintains also broad-spectrum for cancer subtypes, especially with 91.78% sensitivity and 91.96% specificity in patients with AFP-limited liver cancer. In addition, we demonstrate levels of plasma Hsp90α are determined by ADAM10 expression, which will affect Hsp90α content in exosomes. Furthermore, Western blotting and PRM-based quantitative proteomics identify that partial false ELISA-negative patients secret high levels of plasma Hsp90α. Mechanism analysis reveal that TGFß-PKCγ gene signature defines a distinct pool of hyperphosphorylated Hsp90α at Theronine residue. In clinic, a mechanistically relevant population of false ELISA-negative patients express also higher levels of PKCγ. In sum, plasma Hsp90α is a novel pan-cancer diagnosis biomarker, and cancer diagnosis with plasma Hsp90α is particularly effective in those patients with high expression of ADAM10, but may be insufficient to detect the patients with low ADAM10 and those with hyperphosphorylated Hsp90α.


Assuntos
Biomarcadores Tumorais/sangue , Proteínas de Choque Térmico HSP90/sangue , Neoplasias/diagnóstico , Proteína ADAM10/genética , Proteína ADAM10/metabolismo , Adolescente , Adulto , Secretases da Proteína Precursora do Amiloide/genética , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Biomarcadores Tumorais/metabolismo , Linhagem Celular Tumoral , Criança , Pré-Escolar , Conjuntos de Dados como Assunto , Ensaio de Imunoadsorção Enzimática , Exossomos/metabolismo , Reações Falso-Negativas , Feminino , Proteínas de Choque Térmico HSP90/metabolismo , Humanos , Lactente , Recém-Nascido , Masculino , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Pessoa de Meia-Idade , Neoplasias/sangue , Neoplasias/patologia , Fosforilação , Estudos Prospectivos , Curva ROC , Treonina/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto , Adulto Jovem
14.
Nutrients ; 11(7)2019 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-31319549

RESUMO

The prevalence of cognitive impairments and circadian disturbances increases in the elderly and Alzheimer's disease (AD) patients. This study investigated the effects of a standardized extract of Asparagus officinalis stem, ETAS® on cognitive impairments and circadian rhythm status in senescence-accelerated mice prone 8 (SAMP8). ETAS® consists of two major bioactive constituents: 5-hydroxymethyl-2-furfural (HMF), an abundant constituent, and (S)-asfural, a novel constituent, which is a derivative of HMF. Three-month-old SAMP8 male mice were divided into a control, 200 and 1000 mg/kg BW ETAS® groups, while senescence-accelerated resistant mice (SAMR1) were used as the normal control. After 12-week feeding, ETAS® significantly enhanced cognitive performance by an active avoidance test, inhibited the expressions of amyloid-beta precursor protein (APP) and BACE-1 and lowered the accumulation of amyloid ß (Aß) in the brain. ETAS® also significantly increased neuron number in the suprachiasmatic nucleus (SCN) and normalized the expressions of the melatonin receptor 1 (MT1) and melatonin receptor 2 (MT2). In conclusion, ETAS® enhances the cognitive ability, inhibits Aß deposition and normalizes circadian rhythm signaling, suggesting it is beneficial for preventing cognitive impairments and circadian rhythm disturbances in aging.


Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/metabolismo , Asparagus (Planta)/química , Ácido Aspártico Endopeptidases/metabolismo , Extratos Vegetais/farmacologia , Receptor MT1 de Melatonina/metabolismo , Receptor MT2 de Melatonina/metabolismo , Secretases da Proteína Precursora do Amiloide/genética , Animais , Ácido Aspártico Endopeptidases/genética , Ritmo Circadiano , Cognição/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos , Extratos Vegetais/química , Receptor MT2 de Melatonina/genética
15.
Phytochemistry ; 165: 112041, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31203103

RESUMO

Spiroterreusnoids A-F, six undescribed spiro-dioxolane-containing adducts bearing 3,5-dimethylorsellinic acid-based meroterpenoid and 2,3-butanediol moieties were isolated from the endophytic fungus Aspergillus terreus Thom from Tripterygium wilfordii Hook. f. (Celastraceae). The structures of these adducts were established by spectroscopy, single-crystal X-ray diffraction, and experimental electronic circular dichroism (ECD) measurements. Spiroterreusnoids A-F represent the first examples of adducts composed of 3,5-dimethylorsellinic acid-based meroterpenoids. It is noteworthy that spiroterreusnoids A-F possessing a spiro-dioxolane moiety exhibited potential abilities in inhibiting BACE1 (IC50 values ranging from 5.86 to 27.16 µM) and AchE (IC50 values ranging from 22.18 to 32.51 µM), while the other analogues without this fragment displayed no such activities. Taken together, spiroterreusnoids A-F represent the first multitargeted natural adducts that could inhibit BACE1 and AchE, and might provide a new template for the development of new anti-Alzheimer's disease drugs.


Assuntos
Acetilcolinesterase/metabolismo , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Dioxolanos/farmacologia , Inibidores Enzimáticos/farmacologia , Compostos de Espiro/farmacologia , Terpenos/farmacologia , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Ácido Aspártico Endopeptidases/metabolismo , Aspergillus/química , Celastraceae/microbiologia , Dioxolanos/química , Dioxolanos/isolamento & purificação , Enguias , Inibidores Enzimáticos/química , Inibidores Enzimáticos/isolamento & purificação , Humanos , Compostos de Espiro/química , Compostos de Espiro/isolamento & purificação , Terpenos/química , Terpenos/isolamento & purificação
16.
Chem Biol Interact ; 309: 108707, 2019 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-31194956

RESUMO

Alzheimer's disease (AD) is a slow but progressive neurodegenerative disease. One of the pathological hallmarks of AD is the progressive accumulation of ß-amyloid (Aß) in the form of senile plaques, and Aß insult to neuronal cells has been identified as one of the major causes of AD onset. In the present study, we investigated the anti-AD potential of four flavonoids, naringenin, didymin, prunin, and poncirin, by evaluating their ability to inhibit acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and ß-site amyloid precursor protein cleaving enzyme 1 (BACE1). All four flavonoids displayed promising inhibitory activity against AChE, BChE, and BACE1. Structure-activity relationships suggested that glycosylation of naringenin at sugar moieties, and at different positions of the glycosidic linkage, might be closely associated with anti-AD potential. Kinetic and docking studies showed the lowest binding energy and highest affinity for the mixed, competitive, and non-competitive type inhibitors didymin, prunin, and poncirin. Hydrophobic interactions and the number of hydrogen bonds determined the strength of the protein-inhibitor interaction. We also examined the neuroprotective mechanisms by which flavonoids act against Aß25-35-induced toxicity in PC12 cells. Exposure of PC12 cells to 10 µM Aß25-35 for 24 h resulted in a significant decrease in cell viability. In addition, pretreatment of PC12 cells with different concentrations of flavonoids for 1 h significantly reversed the effects of Aß. Furthermore, treatment with the most active flavonoid, didymin, significantly reduced BACE1, APPsß, and C99 expression levels in a dose-dependent manner, without affecting amyloid precursor protein (APP) levels in the amyloidogenic pathway. Together, our results indicate that flavonoids, and in particular didymin, exhibit inhibitory activity in vitro, and may be useful in the development of therapeutic modalities for the treatment of AD.


Assuntos
Acetilcolinesterase/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Butirilcolinesterase/metabolismo , Flavanonas/química , Glicosídeos/farmacologia , Agregados Proteicos/efeitos dos fármacos , Acetilcolinesterase/química , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Peptídeos beta-Amiloides/química , Peptídeos beta-Amiloides/farmacologia , Animais , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Sítios de Ligação , Butirilcolinesterase/química , Domínio Catalítico , Sobrevivência Celular/efeitos dos fármacos , Glicosídeos/química , Cinética , Simulação de Acoplamento Molecular , Células PC12 , Fragmentos de Peptídeos/farmacologia , Substâncias Protetoras/química , Substâncias Protetoras/farmacologia , Ratos , Relação Estrutura-Atividade
17.
Cells ; 8(6)2019 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-31174368

RESUMO

The amyloid precursor protein (APP) is the parent polypeptide from which amyloid-beta (Aß) peptides, key etiological agents of Alzheimer's disease (AD), are generated by sequential proteolytic processing involving ß- and γ-secretases. APP mutations underlie familial, early-onset AD, and the involvement of APP in AD pathology has been extensively studied. However, APP has important physiological roles in the mammalian brain, particularly its modulation of synaptic functions and neuronal survival. Recent works have now shown that APP could directly modulate γ-aminobutyric acid (GABA) neurotransmission in two broad ways. Firstly, APP is shown to interact with and modulate the levels and activity of the neuron-specific Potassium-Chloride (K+-Cl-) cotransporter KCC2/SLC12A5. The latter is key to the maintenance of neuronal chloride (Cl-) levels and the GABA reversal potential (EGABA), and is therefore important for postsynaptic GABAergic inhibition through the ionotropic GABAA receptors. Secondly, APP binds to the sushi domain of metabotropic GABAB receptor 1a (GABABR1a). In this regard, APP complexes and is co-transported with GABAB receptor dimers bearing GABABR1a to the axonal presynaptic plasma membrane. On the other hand, secreted (s)APP generated by secretase cleavages could act as a GABABR1a-binding ligand that modulates presynaptic vesicle release. The discovery of these novel roles and activities of APP in GABAergic neurotransmission underlies the physiological importance of APP in postnatal brain function.


Assuntos
Precursor de Proteína beta-Amiloide/metabolismo , Receptores de GABA/metabolismo , Transmissão Sináptica/fisiologia , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Secretases da Proteína Precursora do Amiloide/metabolismo , Humanos , Neurônios/metabolismo , Simportadores/metabolismo , Sinapses/metabolismo
18.
Nervenarzt ; 90(9): 884-890, 2019 Sep.
Artigo em Alemão | MEDLINE | ID: mdl-31243509

RESUMO

Numerous amyloid-based clinical studies have recently failed. Does this mean that the mechanisms of Alzheimer's disease have to be reinvestigated and that amyloid is not the trigger of the disease? Strong genetic evidence from familial Alzheimer's disease contradicts this fatalistic opinion. Mutations in all genes associated with familial Alzheimer's disease affect amyloid metabolism and aggregation. Moreover, a protective mutation reduces amyloid production by 20-30% throughout the lifetime. Clinical studies rather failed because secretase inhibitors block cleavage of numerous other physiologically important substrates of secretases. Moreover, the disease is initiated decades before symptoms occur. Successful treatment attempts with anti-amyloid medication based on other prototype amyloidoses are described. Finally, new therapeutic target molecules expressed in microglia cells are discussed.


Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides , Doença de Alzheimer/genética , Doença de Alzheimer/fisiopatologia , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/genética , Peptídeos beta-Amiloides/metabolismo , Humanos , Mutação , Pesquisa/normas
19.
Curr Top Med Chem ; 19(13): 1173-1187, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31244427

RESUMO

BACKGROUND: Alzheimers Disease (AD) is a neurodegenerative disease which is characterized by the deposition of amyloid plaques in the brain- a concept supported by most of the researchers worldwide. The main component of the plaques being amyloid-beta (Aß42) results from the sequential cleavage of Amyloid precursor protein (APP) by beta and gamma secretase. This present study intends to inhibit the formation of amyloid plaques by blocking the action of gamma secretase protein with Inhibitors (GSI). METHODS: A number of Gamma Secretase Inhibitors (GSI) were targeted to the protein by molecular docking. The inhibitor having the best affinity was used as a subject for further virtual screening methods to obtain similar compounds. The generated compounds were docked again at the same docking site on the protein to find a compound with higher affinity to inhibit the protein. The highlights of virtually screened compound consisted of Pharmacophore Mapping of the docking site. These steps were followed by comparative assessments for both the compounds, obtained from the two aforesaid docking studies, which included interaction energy descriptors, ADMET profiling and PreADMET evaluations. RESULTS: 111 GSI classified as azepines, sulfonamides and peptide isosteres were used in the study. By molecular docking an amorpholino-amide, compound (22), was identified to be the high affinity compound GSI along with its better interaction profiles.The virtually screened pubchem compound AKOS001083915 (CID:24462213) shows the best affinity with gamma secretase. Collective Pharmacophore mapping (H bonds, electrostatic profile, binding pattern and solvent accesibility) shows a stable interaction. The resulting ADMETand Descriptor values were nearly equivalent. CONCLUSION: These compounds identified herein hold a potential as Gamma Secretase inhibitors.According to PreADMET values the compound AKOS001083915 is effective and specific to the target protein. Its BOILED-egg plot analysis infers the compound permeable to blood brain barrier.Comparative study for both the compounds resulted in having nearly equivalent properties. These compounds have the capacity to inhibit the protein which is indirectly responsible for the formation of amyloid plaques and can be further put to in vitro pharmacokinetic and dynamic studies.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Amidas/farmacologia , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Morfolinas/farmacologia , Bibliotecas de Moléculas Pequenas/farmacologia , Doença de Alzheimer/metabolismo , Amidas/síntese química , Amidas/química , Secretases da Proteína Precursora do Amiloide/metabolismo , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Humanos , Ligações de Hidrogênio , Simulação de Acoplamento Molecular , Morfolinas/síntese química , Morfolinas/química , Bibliotecas de Moléculas Pequenas/química , Relação Estrutura-Atividade
20.
Curr Med Sci ; 39(3): 419-425, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31209813

RESUMO

In order to investigate the role of the Notch signaling pathway in skeletal muscle fibrosis after nerve injury, 60 Sprague-Dawley rats were selected and divided randomly into a control and two experimental groups. Group A served as controls without any treatment. Rats in groups B were injected intraperitoneally with 0.2 mL PBS and those in group C were injected intraperitoneally with 0.2 mL PBS+100 µmol/L, 0.2 mL N-[N-(3,5-difluorophenacetyl)-l-alanyl]- S-phenylglycine t-butyl ester (DAPT, a gamma-secretase inhibitor that suppresses Notch signaling) respectively, on postoperative days 1, 3, 7, 10, and 14 in a model of denervation-induced skeletal muscle fibrosis by right sciatic nerve transection. Five rats from each group were euthanized on postoperative days 1, 7, 14, and 28 to collect the right gastrocnemii, and hematoxylin and eosin (HE) staining, immunohistochemistry test, real-time PCR, and Western blotting were performed to assess connective tissue hyperplasia and fibroblast density as well as expression of Notch 1, Jagged 1, and Notch downstream molecules Hes 1 and collagen I (COL I) on day 28. There was no significant difference in HE-stained fibroblast density between group B and C on postoperative day 1. However, fibroblast density was significantly higher in group B than in group C on postoperative days 7, 14, and 28. Notch 1, Jagged 1, Hes 1, and COL I proteins in the gastrocnemius were expressed at very low levels in group A but at high levels in group B. Expression levels of these proteins were significantly lower in group C than in group B (P<0.05), but they were higher in group C than in group A (P<0.05) on postoperative day 28. We are led to conclude that locking the Notch signaling pathway inhibits fibrosis progression of denervated skeletal muscle. Thus, it may be a new approach for treatment of fibrosis of denervated skeletal muscle.


Assuntos
Secretases da Proteína Precursora do Amiloide/genética , Dipeptídeos/farmacologia , Inibidores Enzimáticos/farmacologia , Fibroblastos/metabolismo , Receptor Notch1/genética , Nervo Isquiático/efeitos dos fármacos , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Colágeno Tipo I/genética , Colágeno Tipo I/metabolismo , Fibroblastos/efeitos dos fármacos , Fibroblastos/patologia , Fibrose/prevenção & controle , Regulação da Expressão Gênica , Músculos Isquiotibiais/efeitos dos fármacos , Músculos Isquiotibiais/inervação , Músculos Isquiotibiais/metabolismo , Injeções Intraperitoneais , Proteína Jagged-1/genética , Proteína Jagged-1/metabolismo , Masculino , Denervação Muscular/métodos , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/inervação , Músculo Esquelético/metabolismo , Ratos , Ratos Sprague-Dawley , Receptor Notch1/antagonistas & inibidores , Receptor Notch1/metabolismo , Nervo Isquiático/lesões , Nervo Isquiático/metabolismo , Transdução de Sinais , Fatores de Transcrição HES-1/genética , Fatores de Transcrição HES-1/metabolismo
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