Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 513
Filtrar
1.
Small ; : e2407154, 2024 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-39392092

RESUMO

The abnormal accumulation of ß-amyloid protein (Aß) is considered as the main pathological hallmark of Alzheimer's disease (AD). The design of potent multifunctional theranostic agents targeting Aß is one of the effective strategies for AD prevention and treatment. Nanomotors as intelligent, advanced, and multifunctional nanoplatforms can perform many complex tasks, but their application in AD theranostics is rare. Herein, sub-10nm multifunctional dual-carbon dots composites (ERCD) with photo-propelled nanomotor behavior are fabricated by conjugating near-infrared (NIR) carbon dots (RCD) of thermogenic and photodynamic capability with the previously reported epigallocatechin gallate-derived carbonized polymer dots (ECD). ERCD-1 (ECD:RCD = 1:2.5) showed potent inhibitory capability similar to ECD in the absence of NIR light, and exhibited photooxygenation activity and nanomotor behavior powered by "self-thermophoretic force" under NIR irradiation, significantly enhancing the inhibition, disaggregation, and photooxygenation capabilities. The nanomotor suppressed Aß fibrillization and rapidly disaggregated mature Aß fibrils at very low concentrations (0.5 µg mL-1). Moreover, the NIR-activated ERCD-1 imaged Aß plaques in vivo and prolonged nematode lifespan by 6 d at 2 µg mL-1. As a proof-of-concept, this work opened a new avenue to the design of multifunctional sub-10nm nanomotors targeting Aß for AD theranostics.

2.
Chembiochem ; 25(13): e202400224, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38668376

RESUMO

Neurodegenerative diseases (NDDs) refer to a complex heterogeneous group of diseases which are associated with the accumulation of amyloid fibrils or plaques in the brain leading to progressive loss of neuronal functions. Alzheimer's disease is one of the major NDD responsible for 60-80 % of all dementia cases. Currently, there are no curative or disease-reversing/modifying molecules for many of the NDDs except a few such as donepezil, rivastigmine, galantamine, carbidopa and levodopa which treat the disease-associated symptoms. Similarly, there are very few FDA-approved tracers such as flortaucipir (Tauvid) for tau fibril imaging and florbetaben (Neuraceq), flutemetamol (Vizamyl), and florbetapir (Amyvid) for amyloid imaging available for diagnosis. Recent advances in the cryogenic electron microscopy reported distinctly different microstructures for tau fibrils associated with different tauopathies highlighting the possibility to develop tauopathy-specific imaging agents and therapeutics. In addition, it is important to identify the proteins that are associated with disease development and progression to know about their 3D structure to develop various diagnostics, therapeutics and theranostic agents. The current article discusses in detail the disease-associated amyloid and non-amyloid proteins along with their structural insights. We comprehensively discussed various novel proteins associated with NDDs and their implications in disease pathology. In addition, we document various emerging chemical compounds developed for diagnosis and therapy of different NDDs with special emphasis on theranostic agents for better management of NDDs.


Assuntos
Doenças Neurodegenerativas , Humanos , Doenças Neurodegenerativas/tratamento farmacológico , Doenças Neurodegenerativas/metabolismo , Proteínas tau/metabolismo , Proteínas tau/antagonistas & inibidores , Amiloide/metabolismo , Amiloide/antagonistas & inibidores , Amiloide/química , Proteínas Amiloidogênicas/metabolismo , Proteínas Amiloidogênicas/química , Proteínas Amiloidogênicas/antagonistas & inibidores , Nanomedicina Teranóstica , Animais
3.
Prostaglandins Other Lipid Mediat ; 175: 106911, 2024 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-39321864

RESUMO

AIM: It was aimed to determine the potential effect of Lactobacillus acidophilus supplementation on rats exposed to an experimental high-fat diet on serum lipid profile and kidney total beta amyloid protein (TBAP) and Tumor Necrosis Factor-alpha (TNF-α) levels. METHODS: 24 male Sprague-Dawley rats were used in the study to establish 4 groups. Standard rat food (SD) was provided to Group 1 as the control; Group 2 was fed a high-fat diet (HFD); Group 3 consumed SD and received L. acidophilus probiotics; Group 4 was fed HFD and received L. acidophilus probiotics. Body weights were determined weekly during the 12-week trial period. At the end of the experiment, TBP and TNF-α levels in the serum and kidney tissue of the rats were measured by ELISA method. Serum total cholesterol (TC), triglyceride (TG), HDL, LDL, urea and creatinine levels and paraoxanase, amylase and lipase activities were determined by spectrophotometric method on the analyzer device. RESULTS: When the control (Group 1) group and Group 2 were compared at the end of the experiment, it was found that Group 2 had gained the most weight and that both the blood and kidney tissue levels of TNF-α and TBAP, as well as the quantities of TG, TK, LDL, and urea, were significantly greater (P<0.05). Serum HDL, PON and amylase levels were found to be significantly low (P>0.05). TG, TK, LDL, urea, and the levels of TNF-α and TBAP in serum and renal tissue were shown to be lower in the groups who received L. acidophilus probiotics (Groups 3, 4) when compared to Group 2 (P>0.05). It was observed that HDL, PON and amylase levels increased and approached the control group (P<0.05). CONCLUSION: The study's findings showed that probiotic supplementation improved blood levels of TG, TC, HDL, LDL, urea, PON, and amylase as well as serum and kidney tissue levels of TNF-α and TBAP in obese rats fed a high-fat diet.

4.
Macromol Rapid Commun ; : e2400596, 2024 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-39319677

RESUMO

Biomimetic slippery liquid-infused porous surfaces (SLIPS) have emerged as a promising solution to solve the limitations of superhydrophobic surfaces, such as inadequate durability in corrosion protection and a propensity for frosting. However, the challenge of ensuring strong, lasting adhesion on diverse materials to enhance the durability of the lubricant layer remains. The research addresses this by leveraging amyloid phase-transitioned lysozyme (PTL) as an adhesive interlayer, conferring stable attachment of SLIPS across a variety of substrates, including metals, inorganics, and polymers. The silica-textured interface robustly secures the lubricant with a notably low sliding angle of 1.15°. PTL-mediated adhesion fortifies the silicone oil attachment to the substrate, ensuring the retention of its repellent efficacy amidst mechanical stressors like ultrasonication, water scrubbing, and centrifugation. The integration of robust adhesion, cross-substrate compatibility, and durability under stress affords the PTL-modified SLIPS exceptional anti-fouling, anti-icing, and anti-corrosion properties, marking it as a leading solution for advanced protective applications.

5.
J Biol Chem ; 298(2): 101569, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35007533

RESUMO

Amyloid proteins are widespread in nature both as pathological species involved in several diseases and as functional entities that can provide protection and storage for the organism. Lipids have been found in amyloid deposits from various amyloid diseases and have been shown to strongly affect the formation and structure of both pathological and functional amyloid proteins. Here, we investigate how fibrillation of the functional amyloid FapC from Pseudomonas is affected by two lysolipids, the zwitterionic lipid 1-myristoyl-2-hydroxy-sn-glycero-3-phosphocholine and the anionic lipid 1-myristoyl-2-hydroxy-sn-glycero-3-phospho-(1'-rac-glycerol) (LPG). Small-angle X-ray scattering, circular dichroism, dynamic light scattering, and thioflavin T fluorescence measurements were performed simultaneously on the same sample to ensure reproducibility and allow a multimethod integrated analysis. We found that LPG strongly induces fibrillation around its critical micelle concentration (cmc) by promoting formation of large structures, which mature via accumulation of intermediate fibril structures with a large cross section. At concentrations above its cmc, LPG strongly inhibits fibrillation by locking FapC in a core-shell complex. In contrast, lipid 1-myristoyl-2-hydroxy-sn-glycero-3-phosphocholine induces fibrillation at concentrations above its cmc, not via strong interactions with FapC but by being incorporated during fibrillation and likely stabilizing the fibrillation nucleus to reduce the lag phase. Finally, we show that LPG is not incorporated into the fibril during assembly but rather can coat the final fibril. We conclude that lipids affect both the mechanism and outcome of fibrillation of functional amyloid, highlighting a role for lipid concentration and composition in the onset and mechanism of fibrillation in vivo.


Assuntos
Amiloide , Lipídeos , Fosforilcolina , Amiloide/química , Proteínas Amiloidogênicas , Metabolismo dos Lipídeos , Lipídeos/química , Pseudomonas/metabolismo , Reprodutibilidade dos Testes
6.
J Biol Chem ; 298(4): 101794, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35248531

RESUMO

Epigenetic regulation plays substantial roles in human pathophysiology, which provides opportunities for intervention in human disorders through the targeting of epigenetic pathways. Recently, emerging evidence from preclinical studies suggested the potential in developing therapeutics of Alzheimer's disease (AD) by targeting bromodomain containing protein 4 (BRD4), an epigenetic regulatory protein. However, further characterization of AD-related pathological events is urgently required. Here, we investigated the effects of pharmacological degradation or inhibition of BRD4 on AD cell models. Interestingly, we found that both degradation and inhibition of BRD4 by ARV-825 and JQ1, respectively, robustly increased the levels of amyloid-beta (Aß), which has been associated with the neuropathology of AD. Subsequently, we characterized the mechanisms by which downregulation of BRD4 increases Aß levels. We found that both degradation and inhibition of BRD4 increased the levels of BACE1, the enzyme responsible for cleavage of the amyloid-beta protein precursor (APP) to generate Aß. Consistent with Aß increase, we also found that downregulation of BRD4 increased AD-related phosphorylated Tau (pTau) protein in our 3D-AD human neural cell culture model. Therefore, our results suggest that downregulation of BRD4 would not be a viable strategy for AD intervention. Collectively, our study not only shows that BRD4 is a novel epigenetic component that regulates BACE1 and Aß levels, but also provides novel and translational insights into the targeting of BRD4 for potential clinical applications.


Assuntos
Doença de Alzheimer , Proteínas de Ciclo Celular , Epigênese Genética , Fatores de Transcrição , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Humanos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
7.
Chembiochem ; 24(22): e202300503, 2023 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-37679300

RESUMO

While the primary pathology of Alzheimer's disease (AD) is defined by brain deposition of amyloid-ß (Aß) plaques and tau neurofibrillary tangles, chronic inflammation has emerged as an important factor in AD etiology. Upregulated cell surface expression of the receptor for advanced glycation end-products (RAGE), a key receptor of innate immune response, is reported in AD. In parallel, RAGE ligands, including Aß aggregates, HMGB1, and S100B, are elevated in AD brain. Activation of RAGE by these ligands triggers release of inflammatory cytokines and upregulates cell surface RAGE. Despite such observation, there are currently no therapeutics that target RAGE for treatment of AD-associated neuroinflammation. Peptoids, a novel class of potential AD therapeutics, display low toxicity, facile blood-brain barrier permeability, and resistance to proteolytic degradation. In the current study, peptoids were designed to mimic Aß, a ligand that binds the V-domain of RAGE, and curtail RAGE inflammatory activation. We reveal the nanomolar binding capability of peptoids JPT1 and JPT1a to RAGE and demonstrate their ability to attenuate lipopolysaccharide-induced pro-inflammatory cytokine production as well as upregulation of RAGE cell surface expression. These results support RAGE antagonist peptoid-based mimics as a prospective therapeutic strategy to counter neuroinflammation in AD and other neurodegenerative diseases.


Assuntos
Doença de Alzheimer , Peptoides , Humanos , Receptor para Produtos Finais de Glicação Avançada/metabolismo , Receptor para Produtos Finais de Glicação Avançada/uso terapêutico , Peptoides/farmacologia , Doenças Neuroinflamatórias , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo
8.
Metab Brain Dis ; 38(6): 1769-1800, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37335453

RESUMO

Alzheimer's disease (AD) and Type 2 diabetes mellitus (T2DM) are two of the most common age-related diseases. There is accumulating evidence of an overlap in the pathophysiological mechanisms of these two diseases. Studies have demonstrated insulin pathway alternation may interact with amyloid-ß protein deposition and tau protein phosphorylation, two essential factors in AD. So attention to the use of anti-diabetic drugs in AD treatment has increased in recent years. In vitro, in vivo, and clinical studies have evaluated possible neuroprotective effects of anti-diabetic different medicines in AD, with some promising results. Here we review the evidence on the therapeutic potential of insulin, metformin, Glucagon-like peptide-1 receptor agonist (GLP1R), thiazolidinediones (TZDs), Dipeptidyl Peptidase IV (DPP IV) Inhibitors, Sulfonylureas, Sodium-glucose Cotransporter-2 (SGLT2) Inhibitors, Alpha-glucosidase inhibitors, and Amylin analog against AD. Given that many questions remain unanswered, further studies are required to confirm the positive effects of anti-diabetic drugs in AD treatment. So to date, no particular anti-diabetic drugs can be recommended to treat AD.


Assuntos
Doença de Alzheimer , Diabetes Mellitus Tipo 2 , Inibidores da Dipeptidil Peptidase IV , Metformina , Humanos , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Diabetes Mellitus Tipo 2/tratamento farmacológico , Metformina/farmacologia , Inibidores da Dipeptidil Peptidase IV/farmacologia , Inibidores da Dipeptidil Peptidase IV/uso terapêutico , Insulina/uso terapêutico , Hipoglicemiantes/farmacologia , Hipoglicemiantes/uso terapêutico
9.
Drug Dev Res ; 84(4): 671-680, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32548880

RESUMO

Current therapeutic drugs for Alzheimer's disease (AD) can only offer limited symptomatic benefits and do not halt disease progression. Multitargeted directed ligands (MTDLs) have been considered to be a feasible way to treat AD due to the multiple neuropathological processes in AD. Previous studies proposed that compounds containing two aromatic groups connected by a carbon chain should act as effective amyloid ß (Aß) aggregation inhibitors although the optimal length of the carbon chain has not been explored. In the current study, a series of naphthalimide analogs were designed and synthesized based on the proposed structure and multiple bioactivities beneficial to the AD treatment were reported. In vitro studies showed that compound 8, which has two aromatic groups connected by a two-carbon chain, exhibited significant inhibition of Aß aggregation through the prevention of elongation and association of Aß fibril growth. Furthermore, this compound also displayed antioxidative activities and neuroprotection from Aß monomer induced toxicity in primary cortical neurons. The results of the present study highlight a novel naphthalimide-based compound 8 as a promising MTDL against AD. Its structural elements can be further explored for enhanced therapeutic capabilities.


Assuntos
Doença de Alzheimer , Humanos , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides , Naftalimidas/farmacologia , Naftalimidas/uso terapêutico , Ligantes , Antioxidantes/farmacologia , Inibidores da Colinesterase/química
10.
Int J Mol Sci ; 24(9)2023 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-37176076

RESUMO

Alzheimer's disease (AD) is a specific neurodegenerative disease. This study adopts single-chain variable fragments (scFvs) as a potential immunotherapeutic precursor for AD. According to the remarkable effects of monoclonal antibodies, such as the depolymerization or promotion of Aß42 efflux by Crenezumab, Solanezumab, and 12B4, it is attractive to prepare corresponding scFvs targeting amyloid-ß-42 protein (Aß42) and investigate their biological activities. Crenezumab-like scFv (scFv-C), Solanezumab-like scFv (scFv-S), and 12B4-like scFv (scFv-12B4) were designed and constructed. The thermal stabilities and binding ability to Aß42 of scFv-C, scFv-S, and scFv-12B4 were evaluated using unfolding profile and enzyme-linked immunosorbent assay. As the results indicated that scFv-C could recognize Aß42 monomer/oligomer and promote the disaggregation of Aß42 fiber as determined by the Thioflavin-T assay, the potential mechanism of its interaction with Aß42 was investigated using molecular dynamics analysis. Interactions involving hydrogen bonds and salt bonds were predicted between scFv-C and Aß42 pentamer, suggesting the possibility of inhibiting further aggregation of Aß42. The successfully prepared scFvs, especially scFv-C, with favorable biological activity targeting Aß42, might be developed for a potentially efficacious clinical application for AD.


Assuntos
Doença de Alzheimer , Doenças Neurodegenerativas , Anticorpos de Cadeia Única , Humanos , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Fragmentos de Peptídeos/química
11.
Plant Foods Hum Nutr ; 78(2): 329-335, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36964883

RESUMO

Durian seeds are normally considered as agricultural waste in durian fruit processing, resulting in a huge waste of resources. The structure characterization of polysaccharide from durian seed and its neuroprotective effects against Alzheimer's disease (AD) in a transgenic Caenorhabditis elegans model were conducted in this study. A water-soluble polysaccharide was obtained using atmospheric pressure plasma treatment, and named DSPP-1. DSPP-1 was composed of rhamnose, galactose and galacturonic acid and its molecular weight was 3.765 × 105 Da. PDSP and DSPP-1 showed considerable antioxidant activity in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging compared to the positive control (vitamin C). Besides, compared with the positive group (epigallocatechin gallate), PDSP and DSPP-1 exhibited the certain Abeta1 - 42 aggregation inhibitory effectiveness (p < 0.05). In contrast, DSPP-2 exerted a poor antioxidant and anti-aggregation effect (p < 0.05). In vivo results showed that DSPP-1 could decrease abnormal Aß1-42 aggregation to delay the paralysis process of AD-nematodes. Moreover, DSPP-1 significantly improved the antioxidant enzyme activities and reduced lipid peroxidation in AD-nematodes. Taken together, these results indicated that DSPP-1 could be used as a potential natural source for the prevention and treatment of AD.


Assuntos
Doença de Alzheimer , Bombacaceae , Animais , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/prevenção & controle , Caenorhabditis elegans , Antioxidantes/farmacologia , Antioxidantes/análise , Peptídeos beta-Amiloides/análise , Sementes/química , Polissacarídeos/farmacologia
12.
Q Rev Biophys ; 53: e12, 2020 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-33148356

RESUMO

In neurodegenerative diseases, a wide range of amyloid proteins or peptides such as amyloid-beta and α-synuclein fail to keep native functional conformations, followed by misfolding and self-assembling into a diverse array of aggregates. The aggregates further exert toxicity leading to the dysfunction, degeneration and loss of cells in the affected organs. Due to the disordered structure of the amyloid proteins, endogenous molecules, such as lipids, are prone to interact with amyloid proteins at a low concentration and influence amyloid cytotoxicity. The heterogeneity of amyloid proteinscomplicates the understanding of the amyloid cytotoxicity when relying only on conventional bulk and ensemble techniques. As complementary tools, single-molecule techniques (SMTs) provide novel insights into the different subpopulations of a heterogeneous amyloid mixture as well as the cytotoxicity, in particular as involved in lipid membranes. This review focuses on the recent advances of a series of SMTs, including single-molecule fluorescence imaging, single-molecule force spectroscopy and single-nanopore electrical recording, for the understanding of the amyloid molecular mechanism. The working principles, benefits and limitations of each technique are discussed and compared in amyloid protein related studies.. We also discuss why SMTs show great potential and are worthy of further investigation with feasibility studies as diagnostic tools of neurodegenerative diseases and which limitations are to be addressed.


Assuntos
Proteínas Amiloidogênicas/química , Amiloidose/diagnóstico , Doenças Neurodegenerativas/diagnóstico , Imagem Individual de Molécula , Animais , Biomarcadores/metabolismo , Transferência Ressonante de Energia de Fluorescência , Humanos , Microscopia de Força Atômica , Microscopia de Fluorescência , Nanoporos , Nanotecnologia , Óptica e Fotônica , Desnaturação Proteica , Dobramento de Proteína
13.
Chembiochem ; 23(2): e202100581, 2022 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-34708897

RESUMO

The interfacial interaction within the amyloid protein corona based on MoS2 nanomaterial is crucial, both for understanding the biological effects of MoS2 nanomaterial and the evolution of amyloid diseases. The specific nano-bio interface phenomenon of human islet amyloid peptide (hIAPP) and MoS2 nanosheet was investigated by using theoretical and experimental methods. The MoS2 nanosheet enables the attraction of hIAPP monomer, dimer, and oligomer on its surface through van der Waals forces. Especially, the means of interaction between two hIAPP peptides might be changed by MoS2 nanosheet. In addition, it is interesting to find that the hIAPP oligomer can stably interact with the MoS2 nanosheet in one unique "standing" binding mode with an entire exposed ß-sheet surface. All the interaction modes on the surface of MoS2 nanosheet can be the essence of amyloid protein corona that may provide the venue to facilitate the fibrillation of hIAPP proteins. Further, it was verified experimentally that MoS2 nanosheets could accelerate the fibrillation of hIAPP at a certain concentration mainly based on the newly formed nano-bio interface. In general, our results provide insight into the molecular interaction mechanism of the nano-bio interface within the amyloid protein corona, and shed light on the pathway of amyloid protein aggregation that is related to the evolution of amyloid diseases.


Assuntos
Dissulfetos/química , Polipeptídeo Amiloide das Ilhotas Pancreáticas/química , Molibdênio/química , Nanoestruturas/química , Coroa de Proteína/química , Biopolímeros/química , Humanos , Simulação de Dinâmica Molecular , Conformação Proteica em Folha beta , Estrutura Secundária de Proteína
14.
Neuropathol Appl Neurobiol ; 48(3): e12782, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34823269

RESUMO

The pathological processes leading to synapse loss, neuronal loss, brain atrophy and gliosis in Alzheimer's disease (AD) and their relation to vascular disease and immunological changes are yet to be fully explored. Amyloid-ß (Aß) aggregation, vascular damage and altered immune response interact at the blood-brain barrier (BBB), affecting the brain endothelium and fuelling neurodegeneration. The aim of the present systematic literature review was to critically appraise and to summarise the published evidence on the clinical correlations and pathophysiological concepts of BBB damage in AD, focusing on human data. The PubMed, Cochrane, Medline and Embase databases were searched for original research articles, systematic reviews and meta-analyses, published in English language from 01/2000 to 07/2021, using the keywords Alzheimer*, amyloid-ß or ß-amyloid or abeta and BBB. This review shows that specific changes of intercellular structures, reduced expression of transendothelial carriers, induction of vasoactive mediators and activation of both astroglia and monocytes/macrophages characterise BBB damage in human AD and AD models. BBB dysfunction on magnetic resonance imaging takes place early in the disease course in AD-specific brain regions. The toxic effects of Aß and apolipoprotein E (ApoE) are likely to induce a non-cerebral-amyloid-angiopathy-related degeneration of endothelial cells, independently of cerebrovascular disease; however, some of the observed structural changes may just arise with age. Small vessel disease, ApoE, loss of pericytes, proinflammatory signalling and cerebral amyloid angiopathy enhance BBB damage. Novel therapeutic approaches for AD, including magnetic resonance-guided focused ultrasound, aim to open the BBB, potentially leading to an improved drainage of Aß along perivascular channels and increased elimination from the brain. In vitro treatments with ApoE-modifying agents yielded promising effects on modulating BBB function. Reducing cardiovascular risk factors represents one of the most promising interventions for dementia prevention at present. However, further research is needed to elucidate the connection of BBB damage and tau pathology, the role of proinflammatory mediators in draining macromolecules and cells from the cerebral parenchyma, including their contribution to cerebral amyloid angiopathy. Improved insight into these pathomechanisms may allow to shed light on the role of Aß deposition as a primary versus a secondary event in the complex pathogenesis of AD.


Assuntos
Doença de Alzheimer , Angiopatia Amiloide Cerebral , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Barreira Hematoencefálica/patologia , Encéfalo/patologia , Angiopatia Amiloide Cerebral/patologia , Células Endoteliais/patologia , Humanos
15.
FASEB J ; 35(5): e21445, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33774866

RESUMO

Mitochondrial Tu translation elongation factor (TUFM or EF-Tu) is part of the mitochondrial translation machinery. It is reported that TUFM expression is reduced in the brain of Alzheimer's disease (AD), suggesting that TUFM might play a role in the pathophysiology. In this study, we found that TUFM protein level was decreased in the hippocampus and cortex especially in the aged APP/PS1 mice, an animal model of AD. In HEK cells that stably express full-length human amyloid-ß precursor protein (HEK-APP), TUFM knockdown or overexpression increased or reduced the protein levels of ß-amyloid protein (Aß) and ß-amyloid converting enzyme 1 (BACE1), respectively. TUFM-mediated reduction of BACE1 was attenuated by translation inhibitor cycloheximide (CHX) or α-[2-[4-(3,4-Dichlorophenyl)-2-thiazolyl]hydrazinylidene]-2-nitro-benzenepropanoic acid (4EGI1), and in cells overexpressing BACE1 constructs deleting the 5' untranslated region (5'UTR). TUFM silencing increased the half-life of BACE1 mRNA, suggesting that RNA stability was affected by TUFM. In support, transcription inhibitor Actinomycin D (ActD) and silencing of nuclear factor κB (NFκB) failed to abolish TUFM-mediated regulation of BACE1 protein and mRNA. We further found that the mitochondria-targeted antioxidant TEMPO diminished the effects of TUFM on BACE1, suggesting that reactive oxygen species (ROS) played an important role. Indeed, cellular ROS levels were affected by TUFM knockdown or overexpression, and TUFM-mediated regulation of apoptosis and Tau phosphorylation at selective sites was attenuated by TEMPO. Collectively, TUFM protein levels were decreased in APP/PS1 mice. TUFM is involved in AD pathology by regulating BACE1 translation, apoptosis, and Tau phosphorylation, in which ROS plays an important role.


Assuntos
Doença de Alzheimer/patologia , Secretases da Proteína Precursora do Amiloide/metabolismo , Modelos Animais de Doenças , Mitocôndrias/patologia , Fator Tu de Elongação de Peptídeos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide/genética , Precursor de Proteína beta-Amiloide/fisiologia , Animais , Humanos , Camundongos , Camundongos Transgênicos , Mitocôndrias/metabolismo , Fator Tu de Elongação de Peptídeos/genética , Fosforilação , Presenilina-1/fisiologia
16.
Virol J ; 19(1): 151, 2022 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-36127711

RESUMO

BACKGROUND: ß-Amyloid (Aß) protein is a pivotal pathogenetic factor in Alzheimer's disease (AD). However, increasing evidence suggests that the brain has to continuously produce excessive Aß to efficaciously prevent pathogenic micro-organism infections, which induces and accelerates the disease process of AD. Meanwhile, Aß exhibits activity against herpes simplex virus type 1 (HSV-1) and influenza A virus (IAV) replication, but not against other neurotropic viruses. Enterovirus A71 (EV-A71) is the most important neurotropic enterovirus in the post-polio era. Given the limitation of existing research on the relationship between Aß and other virus infections, this study aimed to investigate the potent activity of Aß on EV-A71 infection and extended the potential function of Aß in other unenveloped viruses may be linked to Alzheimer's disease or infectious neurological diseases. METHODS: Aß peptides 1-42 are a major pathological factor of senile plaques in Alzheimer's disease (AD). Thus, we utilized Aß1-42 as a test subject to perform our study. The production of monomer Aß1-42 and their high-molecular oligomer accumulations in neural cells were detected by immunofluorescence assay, ELISA, or Western blot assay. The inhibitory activity of Aß1-42 peptides against EV-A71 in vitro was detected by Western blot analysis or qRT-PCR. The mechanism of Aß1-42 against EV-A71 replication was analyzed by time-of-addition assay, attachment inhibition assay, pre-attachment inhibition analysis, viral-penetration inhibition assay, TEM analysis of virus agglutination, and pull-down assay. RESULTS: We found that EV-A71 infection induced Aß production and accumulation in SH-SY5Y cells. We also revealed for the first time that Aß1-42 efficiently inhibited the RNA level of EV-A71 VP1, and the protein levels of VP1, VP2, and nonstructural protein 3AB in SH-SY5Y, Vero, and human rhabdomyosarcoma (RD) cells. Mechanistically, we demonstrated that Aß1-42 primarily targeted the early stage of EV-A71 entry to inhibit virus replication by binding virus capsid protein VP1 or scavenger receptor class B member 2. Moreover, Aß1-42 formed non-enveloped EV-A71 particle aggregates within a certain period and bound to the capsid protein VP1, which partially caused Aß1-42 to prevent viruses from infecting cells. CONCLUSIONS: Our findings unveiled that Aß1-42 effectively inhibited nonenveloped EV-A71 by targeting the early phase of an EV-A71 life cycle, thereby extending the potential function of Aß in other non-envelope viruses linked to infectious neurological diseases.


Assuntos
Doença de Alzheimer , Enterovirus Humano A , Infecções por Enterovirus , Enterovirus , Neuroblastoma , Peptídeos beta-Amiloides , Antígenos Virais/genética , Proteínas do Capsídeo/genética , Enterovirus/genética , Enterovirus Humano A/genética , Humanos , Fragmentos de Peptídeos , RNA , Receptores Depuradores/metabolismo
17.
Fish Shellfish Immunol ; 122: 495-500, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35202805

RESUMO

Serum amyloid protein (SAA) is known as an acute reactive protein of innate immunity in mammals. However, in invertebrates, the role of SAA in innate immunity is still unclear. In this study, a full-length cDNA of the SAA gene (named TcSAA) was cloned from Tridacna crocea, mollusca. The gene includes a 193 bp 5' untranslated region (UTR) and a 129 bp 3' UTR sequence, and the open reading frame (ORF) with 393 bp nucleotides encodes a polypeptide of 130 amino acids. TcSAA contains a typical signal peptide and an SAA functional domain. The mRNA expression of TcSAA was detected in all 12 selected tissues and 7 different developmental stages. Furthermore, the expression of TcSAA was increased quickly in hemocytes after challenge with V. coralliilyticus or LPS. Furthermore, rTcSAA could bind V. coralliilyticus and V. alginolyticus, and the protein could reduce the lethality rate of the clams from 80% to 55% which caused by V. coralliilyticus about 48 h after injection. In summary, these results indicate that TcSAA may act as a marker for monitoring health and protecting T. crocea.


Assuntos
Perciformes , Sequência de Aminoácidos , Proteínas Amiloidogênicas/genética , Proteínas Amiloidogênicas/metabolismo , Animais , Sequência de Bases , Clonagem Molecular , DNA Complementar/genética , Proteínas de Peixes/genética , Regulação da Expressão Gênica , Imunidade Inata/genética , Mamíferos/genética , Mamíferos/metabolismo , Filogenia
18.
J Clin Lab Anal ; 36(9): e24576, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35838016

RESUMO

BACKGROUND: As a chronic systemic autoimmune disease of undetermined etiology, rheumatoid arthritis (RA) has a complex pathogenesis, which involves multiple proteins and cytokines. The 2010 ACR/EULAR classification criteria facilitate early diagnosis of RA with reduced specificity when compared to the 1987 ACR criteria. Hence, it is imperative to identify novel serological inflammatory indicators and targets, in order to explain the complex regulatory network of RA. The present review discusses the associations of various inflammatory factors with RA and its underlying mechanism. Besides, the review also provides a novel insight into the clinical treatment of RA. MATERIALS AND METHODS: According to the PRISMA guidelines, databases like Web of Science, Google-Scholar, Pubmed and Scopus were systematically searched for articles from January 1, 2018 to January 1, 2022 using The following 2 keywords: "rheumatoid arthritis", "Inflammatory cytokines", "ILs", "serum amyloid protein A", "matrix metalloproteinase 3", "RANKL", "Glucose-6-phosphoisomerase", "Anti-keratin antibody", "1,25-Dihydroxyvitamin D3". RESULTS: Indicators like MMPs, ILs, glucose-6-phosphate isomerase (GPI), anti-keratin antibody (AKA) and receptor activator of nuclear factor-κB ligand (RANKL) are the current hotspots in the efficacy research of RA. The present review suggests that ILs are highly expressed in the serum and synovial tissues of RA patients. By targeted inhibition of ILs with inhibitor application, precise RA treatment can be achieved. CONCLUSIONS: Based on these results, it can be concluded that inflammatory factors have certain guiding significance in the diagnosis and efficacy evaluation of RA. However, the mechanisms of interactions among them are rather complex, which deserve further exploration.


Assuntos
Artrite Reumatoide , Autoanticorpos , Citocinas , Diagnóstico Precoce , Humanos
19.
Drug Chem Toxicol ; 45(2): 839-849, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32907430

RESUMO

This study investigated the exposure of pyrethroids in the development of Alzheimer's type neurodegeneration by analyzing ß- amyloid, tau and Glial Fibrillary Acidic Protein (GFAP) in adult Wistar rats. Forty adult Wistar rats (130-150 g) of both sexes were assigned into five groups (n = 8). Groups A-C were treated with three different sub-lethal doses (75, 50 and 25%)of the pyrethroids formulation diluted with olive oil once/daily for 45 days, while groups D&E received olive oil and distilled water respectively (as control groups). During the treatments, physical clinical signs were monitored for cognitive behavioral studies involving object recognition tasks and novel object identification test. At the end of treatment, the rats were sacrificed by cervical dislocation, the brains were harvested and the hippocampus located and dissected out for immunohistochemical studies. Standard histochemical techniques were employed. The results showed a significant decrease (p ≤ 0.05) in the spontaneous alternation and discrimination index in the treatment groups when compared to the control groups. Histological observation showed nuclear fragmentation in treated rats in a dose dependent manner when compared to the controls. Amyloid plaques were further observed and markedly stained with Congo-red in the treated rats compared to the control groups. Immunohistochemical observation revealed that exposure to pyrethroids increased immunoreactivity of GFAP and tau protein in both CA3 and Dentate gyrus (DG) regions in the treated rats indicative of Alzheimer's type degenerative diseases.


Assuntos
Doença de Alzheimer , Piretrinas , Doença de Alzheimer/induzido quimicamente , Peptídeos beta-Amiloides/metabolismo , Animais , Feminino , Masculino , Emaranhados Neurofibrilares/metabolismo , Emaranhados Neurofibrilares/patologia , Piretrinas/toxicidade , Ratos , Ratos Wistar
20.
Genomics ; 113(1 Pt 2): 689-698, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33017626

RESUMO

Fast, accurate identification and characterization of amyloid proteins at a large-scale is essential for understating their role in therapeutic intervention strategies. As a matter of fact, there exist only one in silico model for amyloid protein identification using the random forest (RF) model in conjunction with various feature types namely the RFAmy. However, it suffers from low interpretability for biologists. Thus, it is highly desirable to develop a simple and easily interpretable prediction method with robust accuracy as compared to the existing complicated model. In this study, we propose iAMY-SCM, the first scoring card method-based predictor for predicting and analyzing amyloid proteins. Herein, the iAMY-SCM made use of a simple weighted-sum function in conjunction with the propensity scores of dipeptides for the amyloid protein identification. Cross-validation results indicated that iAMY-SCM provided an accuracy of 0.895 that corresponded to 10-22% higher performance than that of widely used machine learning models. Furthermore, iAMY-SCM achieving an accuracy of 0.827 as evaluated by an independent test, which was found to be comparable to that of RFAmy and was approximately 9-13% higher than widely used machine learning models. Furthermore, the analysis of estimated propensity scores of amino acids and dipeptides were performed to provide insights into the biophysical and biochemical properties of amyloid proteins. As such, this demonstrates that the proposed iAMY-SCM is efficient and reliable in terms of simplicity, interpretability and implementation. To facilitate ease of use of the proposed iAMY-SCM, a user-friendly and publicly accessible web server at http://camt.pythonanywhere.com/iAMY-SCM has been established. We anticipate that that iAMY-SCM will be an important tool for facilitating the large-scale prediction and characterization of amyloid protein.


Assuntos
Amiloide/química , Análise de Sequência de Proteína/métodos , Software , Amiloide/genética , Amiloide/metabolismo , Aprendizado de Máquina , Pontuação de Propensão , Conformação Proteica , Multimerização Proteica
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa