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1.
Hum Mol Genet ; 30(12): 1084-1100, 2021 06 09.
Artículo en Inglés | MEDLINE | ID: mdl-33783499

RESUMEN

RNA-binding proteins (RBPs) play essential roles in diverse cellular processes through post-transcriptional regulation of RNAs. The subcellular localization of RBPs is thus under tight control, the breakdown of which is associated with aberrant cytoplasmic accumulation of nuclear RBPs such as TDP-43 and FUS, well-known pathological markers for amyotrophic lateral sclerosis and frontotemporal dementia (ALS/FTD). Here, we report in Drosophila model for ALS/FTD that nuclear accumulation of a cytoplasmic RBP Staufen may be a new pathological feature. We found that in Drosophila C4da neurons expressing PR36, one of the arginine-rich dipeptide repeat proteins (DPRs), Staufen accumulated in the nucleus in Importin- and RNA-dependent manner. Notably, expressing Staufen with exogenous NLS-but not with mutated endogenous NLS-potentiated PR-induced dendritic defect, suggesting that nuclear-accumulated Staufen can enhance PR toxicity. PR36 expression increased Fibrillarin staining in the nucleolus, which was enhanced by heterozygous mutation of stau (stau+/-), a gene that codes Staufen. Furthermore, knockdown of fib, which codes Fibrillarin, exacerbated retinal degeneration mediated by PR toxicity, suggesting that increased amount of Fibrillarin by stau+/- is protective. stau+/- also reduced the amount of PR-induced nuclear-accumulated Staufen and mitigated retinal degeneration and rescued viability of flies expressing PR36. Taken together, our data show that nuclear accumulation of Staufen in neurons may be an important pathological feature contributing to the pathogenesis of ALS/FTD.


Asunto(s)
Esclerosis Amiotrófica Lateral/genética , Proteínas de Unión al ADN/genética , Proteínas de Drosophila/genética , Demencia Frontotemporal/genética , Ribonucleoproteína Heterogénea-Nuclear Grupo F-H/genética , Proteínas de Unión al ARN/genética , ARN/genética , Esclerosis Amiotrófica Lateral/patología , Animales , Arginina/genética , Proteína C9orf72/genética , Núcleo Celular/genética , Citoplasma/genética , Dipéptidos/genética , Modelos Animales de Enfermedad , Drosophila melanogaster/genética , Demencia Frontotemporal/patología , Técnicas de Silenciamiento del Gen , Humanos , Neuronas/metabolismo , Neuronas/patología , Señales de Localización Nuclear/genética , Procesamiento Postranscripcional del ARN/genética
2.
Anal Chem ; 95(48): 17603-17612, 2023 12 05.
Artículo en Inglés | MEDLINE | ID: mdl-37973790

RESUMEN

Despite the rapid advances in process analytical technology, the assessment of protein refolding efficiency has largely relied on off-line protein-specific assays and/or chromatographic procedures such as reversed-phase high-performance liquid chromatography and size exclusion chromatography. Due to the inherent time gap pertaining to traditional methods, exploring optimum refolding conditions for many recombinant proteins, often expressed as insoluble inclusion bodies, has proven challenging. The present study describes a novel protein refolding sensor that utilizes liquid crystals (LCs) to discriminate varying protein structures during unfolding and refolding. An LC layer containing 4-cyano-4'-pentylbiphenyl (5CB) intercalated with 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) is used as a sensing platform, and its proof-of-concept performance is demonstrated using lysozyme as a model protein. As proteins unfold or refold, a local charge fluctuation at their surfaces modulates their interaction with zwitterionic phospholipid DOPE. This alters the alignment of DOPE molecules at the aqueous/LC interface, affecting the orientational ordering of bulk LC (i.e., homeotropic to planar for refolding and planar to homeotropic for unfolding). Differential polarized optical microscope images of the LC layer are subsequently generated, whose brightness directly linked to conformational changes of lysozyme molecules is quantified by gray scale analysis. Importantly, our LC-based refolding sensor is compatible with diverse refolding milieus for real-time analysis of lysozyme refolding and thus likely to facilitate the refolding studies of many proteins, especially those lacking a method to determine structure-dependent biological activity.


Asunto(s)
Cristales Líquidos , Muramidasa , Cristales Líquidos/química , Fosfolípidos/química , Compuestos de Bifenilo/química
3.
Small ; 18(42): e2203874, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36116115

RESUMEN

Lithium batteries occupy the large-scale electric mobility market raising concerns about the environmental impact of cell production, especially regarding the use of poly(vinylidene difluoride) (teratogenic) and N-methyl-2-pyrrolidone (NMP, harmful). To avoid their use, an aqueous electrode processing route is utilized in which a water-soluble hybrid acrylic-fluoropolymer together with sodium carboxymethyl cellulose is used as binder, and a thin phosphate coating layer is in situ formed on the surface of the nickel-rich cathode during electrode processing. The resulting electrodes achieve a comparable performance to that of NMP-based electrodes in conventional organic carbonate-based electrolyte (LP30). Subsequently, an ionic liquid electrolyte (ILE) is employed to replace the organic electrolyte, building stable electrode/electrolyte interphases on the surface of the nickel-rich positive electrode (cathode) and metallic lithium negative electrode (anode). In such ILE, the aqueously processed electrodes achieve high cycling stability with a capacity retention of 91% after 1000 cycles (20 °C). In addition, a high capacity of more than 2.5 mAh cm-2 is achieved for high loading electrodes (≈15 mg cm-2 ) by using a modified ILE with 5% vinylene carbonate additive. A path to achieve environmentally friendly electrode manufacturing while maintaining their outstanding performance and structural integrity is demonstrated.

4.
Lifetime Data Anal ; 28(2): 169-193, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35034213

RESUMEN

Missing covariates are commonly encountered when evaluating covariate effects on survival outcomes. Excluding missing data from the analysis may lead to biased parameter estimation and a misleading conclusion. The inverse probability weighting method is widely used to handle missing covariates. However, obtaining asymptotic variance in frequentist inference is complicated because it involves estimating parameters for propensity scores. In this paper, we propose a new approach based on an approximate Bayesian method without using Taylor expansion to handle missing covariates for survival data. We consider a stratified proportional hazards model so that it can be used for the non-proportional hazards structure. Two cases for missing pattern are studied: a single missing pattern and multiple missing patterns. The proposed estimators are shown to be consistent and asymptotically normal, which matches the frequentist asymptotic properties. Simulation studies show that our proposed estimators are asymptotically unbiased and the credible region obtained from posterior distribution is close to the frequentist confidence interval. The algorithm is straightforward and computationally efficient. We apply the proposed method to a stem cell transplantation data set.


Asunto(s)
Proyectos de Investigación , Teorema de Bayes , Simulación por Computador , Humanos , Probabilidad , Modelos de Riesgos Proporcionales
5.
PLoS Comput Biol ; 16(7): e1008099, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32706788

RESUMEN

Next-generation sequencing (NGS) technology has become a powerful tool for dissecting the molecular and pathological signatures of a variety of human diseases. However, the limited availability of biological samples from different disease stages is a major hurdle in studying disease progressions and identifying early pathological changes. Deep learning techniques have recently begun to be applied to analyze NGS data and thereby predict the progression of biological processes. In this study, we applied a deep learning technique called generative adversarial networks (GANs) to predict the molecular progress of Alzheimer's disease (AD). We successfully applied GANs to analyze RNA-seq data from a 5xFAD mouse model of AD, which recapitulates major AD features of massive amyloid-ß (Aß) accumulation in the brain. We examined how the generator is featured to have specific-sample generation and biological gene association. Based on the above observations, we suggested virtual disease progress by latent space interpolation to yield the transition curves of various genes with pathological changes from normal to AD state. By performing pathway analysis based on the transition curve patterns, we identified several pathological processes with progressive changes, such as inflammatory systems and synapse functions, which have previously been demonstrated to be involved in the pathogenesis of AD. Interestingly, our analysis indicates that alteration of cholesterol biosynthesis begins at a very early stage of AD, suggesting that it is the first effect to mediate the cholesterol metabolism of AD downstream of Aß accumulation. Here, we suggest that GANs are a useful tool to study disease progression, leading to the identification of early pathological signatures.


Asunto(s)
Enfermedad de Alzheimer/fisiopatología , RNA-Seq , Algoritmos , Enfermedad de Alzheimer/genética , Precursor de Proteína beta-Amiloide/genética , Animales , Encéfalo/metabolismo , Corteza Cerebral/metabolismo , Colesterol/metabolismo , Análisis por Conglomerados , Aprendizaje Profundo , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Humanos , Inflamación , Ratones , Modelos Genéticos , ARN Mensajero/metabolismo , Sinapsis/metabolismo , Lóbulo Temporal/metabolismo , Secuenciación del Exoma
6.
BMC Public Health ; 20(1): 511, 2020 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-32299403

RESUMEN

BACKGROUND: Weight-for-height Z-score (WHZ) and Mid Upper Arm Circumference (MUAC) are both commonly used as acute malnutrition screening criteria. However, there exists disparity between the groups identified as malnourished by them. Thus, here we aim to investigate the clinical features and linkage with chronicity of the acute malnutrition cases identified by either WHZ or MUAC. Besides, there exists evidence indicating that fat restoration is disproportionately rapid compared to that of muscle gain in hospitalized malnourished children but related research at community level is lacking. In this study we suggest proxy measure to inspect body composition restoration responding to malnutrition management among the malnourished children. METHODS: The data of this study is from World Vision South Sudan's emergency nutrition program from 2006 to 2012 (4443 children) and the nutrition survey conducted in 2014 (3367 children). The study investigated clinical presentations of each type of severe acute malnutrition (SAM) by WHZ (SAM-WHZ) or MUAC (SAM-MUAC), and analysed correlation between each malnutrition and chronic malnutrition. Furthermore, we explored the pattern of body composition restoration during the recovery phase by comparing the relative velocity of MUAC3 with that of weight gain. RESULTS: As acutely malnourished children identified by MUAC more often share clinical features related to chronic malnutrition and minimal overlapping with malnourished children by WHZ, Therefore, MUAC only screening in the nutrition program would result in delayed identification of the malnourished children. CONCLUSIONS: The relative velocity of MUAC3 gain was suggested as a proxy measure for volume increase, and it was more prominent than that of weight gain among the children with SAM by WHZ and MUAC over all the restoring period. Based on this we made a conjecture about dominant fat mass gain over the period of CMAM program. Also, considering initial weight gain could be ascribed to fat mass increase, the current discharge criteria would leave the malnourished children at risk of mortality even after treatment due to limited restoration of muscle mass. Given this, further research should be followed including assessment of body composition for evidence to recapitulate and reconsider the current admission and discharge criteria for CMAM program.


Asunto(s)
Peso Corporal , Trastornos de la Nutrición del Niño/diagnóstico , Hospitalización/estadística & datos numéricos , Estado Nutricional , Desnutrición Aguda Severa/diagnóstico , Antropometría/métodos , Composición Corporal , Tamaño Corporal , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Encuestas Nutricionales , Sudán del Sur , Síndrome Debilitante/diagnóstico , Aumento de Peso
7.
J Nanosci Nanotechnol ; 19(5): 2876-2881, 2019 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-30501794

RESUMEN

Herein, Ni0.8Co0.15Al0.05(OH)2 materials, a by-product in the preparation of the precursor of cathode materials for lithium ion batteries, were employed as supercapacitor electrodes. The reaction time was changed from 2 to 48 h to produce hydroxide products, which were analyzed using physical and electrochemical methods. The hydroxide material reacted for 2 h exhibited a good average particle strength of 34.3 MPa with a particle size of 7 µm. When used as a supercapacitor electrode, the 2 h-reacted hydroxide electrode presented a high capacitance of 244.7 F g-1 at a current density of 0.5 A g-1 with a typical pseudocapacitive behavior, indicative of a highly suitable supercapacitor electrode material.

8.
Int J Mol Sci ; 20(3)2019 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-30678217

RESUMEN

Chronic neuroinflammation is a common feature of the aged brain, and its association with the major neurodegenerative changes involved in cognitive impairment and motor dysfunction is well established. One of the most potent antiaging interventions tested so far is dietary restriction (DR), which extends the lifespan in various organisms. Microglia and astrocytes are two major types of glial cells involved in the regulation of neuroinflammation. Accumulating evidence suggests that the age-related proinflammatory activation of astrocytes and microglia is attenuated under DR. However, the molecular mechanisms underlying DR-mediated regulation of neuroinflammation are not well understood. Here, we review the current understanding of the effects of DR on neuroinflammation and suggest an underlying mechanistic link between DR and neuroinflammation that may provide novel insights into the role of DR in aging and age-associated brain disorders.


Asunto(s)
Astrocitos/metabolismo , Inflamación/metabolismo , Microglía/metabolismo , Animales , Astrocitos/inmunología , Encefalopatías/inmunología , Encefalopatías/metabolismo , Restricción Calórica , Humanos , Inflamación/inmunología , Microglía/inmunología
9.
Molecules ; 24(24)2019 Dec 17.
Artículo en Inglés | MEDLINE | ID: mdl-31861185

RESUMEN

Herein, thermal decomposition experiments of lithium peroxide (Li2O2) were performed to prepare a precursor (Li2O) for sacrificing cathode material, Li2NiO2. The Li2O2 was prepared by a hydrometallurgical reaction between LiOH·H2O and H2O2. The overall reaction during annealing was found to involve the following three steps: (1) dehydration of LiOH·H2O, (2) decomposition of Li2O2, and (3) pyrolysis of the remaining anhydrous LiOH. This stepwise reaction was elucidated by thermal gravimetric and quantitative X-ray diffraction analyses. Furthermore, over-lithiated lithium nickel oxide (Li2NiO2) using our lithium precursor was synthesized, which exhibited a larger yield of 90.9% and higher irreversible capacity of 261 to 265 mAh g-1 than the sample prepared by commercially purchased Li2O (45.6% and 177 to 185 mAh g-1, respectively) due to optimal powder preparation conditions.


Asunto(s)
Suministros de Energía Eléctrica , Iones/química , Litio/química , Níquel/química , Difracción de Rayos X
10.
J Nanosci Nanotechnol ; 17(1): 389-97, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-29620840

RESUMEN

Using a stabilizing agent-assisted co-assembly method, a novel nanocomposite of mesoporous carbon embedded with uniform tungsten oxide nanorods is obtained, which is converted into carbon-sheathed tungsten oxide nanoparticles by delicate calcination and further reduction. Through optimization of tungsten content, it is found that highly crystalline tungsten oxide nanoparticles are uniformly coated with an ultra-thin carbon layer. When applied into electrochemical charge-storage electrodes for supercapacitor and lithium-ion battery, an excellent average capacitance (129 F g−1, above 400 F cm−3), higher rate performance and significantly advanced cycle stability are observed. These improved charge storage properties are attributed to improved electrical conductivity and enhanced structural stability, which is induced by uniform carbon coating on partially reduced tungsten oxide nanoparticles.

11.
J Neurosci ; 35(44): 14717-26, 2015 Nov 04.
Artículo en Inglés | MEDLINE | ID: mdl-26538644

RESUMEN

Dysregulation of amyloid-ß (Aß) metabolism is critical for Alzheimer's disease (AD) pathogenesis. Mounting evidence suggests that apolipoprotein E (ApoE) is involved in Aß metabolism. ATP-binding cassette transporter A1 (ABCA1) is a key regulator of ApoE lipidation, which affects Aß levels. Therefore, identifying regulatory mechanisms of ABCA1 expression in the brain may provide new therapeutic targets for AD. Here, we demonstrate that microRNA-33 (miR-33) regulates ABCA1 and Aß levels in the brain. Overexpression of miR-33 impaired cellular cholesterol efflux and dramatically increased extracellular Aß levels by promoting Aß secretion and impairing Aß clearance in neural cells. In contrast, genetic deletion of mir-33 in mice dramatically increased ABCA1 levels and ApoE lipidation, but it decreased endogenous Aß levels in cortex. Most importantly, pharmacological inhibition of miR-33 via antisense oligonucleotide specifically in the brain markedly decreased Aß levels in cortex of APP/PS1 mice, representing a potential therapeutic strategy for AD. SIGNIFICANCE STATEMENT: Brain lipid metabolism, in particular Apolipoprotein E (ApoE) lipidation, is critical to Aß metabolism and Alzheimer's disease (AD). Brain lipid metabolism is largely separated from the periphery due to blood-brain barrier and different repertoire of lipoproteins. Therefore, identifying the novel regulatory mechanism of brain lipid metabolism may provide a new therapeutic strategy for AD. Although there have been studies on brain lipid metabolism, its regulation, in particular by microRNAs, is relatively unknown. Here, we demonstrate that inhibition of microRNA-33 increases lipidation of brain ApoE and reduces Aß levels by inducing ABCA1. We provide a unique approach for AD therapeutics to increase ApoE lipidation and reduce Aß levels via pharmacological inhibition of microRNA in vivo.


Asunto(s)
Péptidos beta-Amiloides/metabolismo , Apolipoproteínas E/metabolismo , Encéfalo/metabolismo , Metabolismo de los Lípidos/fisiología , MicroARNs/fisiología , Péptidos beta-Amiloides/genética , Animales , Secuencia de Bases , Humanos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Datos de Secuencia Molecular
12.
J Neurochem ; 137(3): 436-45, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26710318

RESUMEN

Accumulation of amyloid ß (Aß) in the brain is a key pathological hallmark of Alzheimer's disease (AD). Because aging is the most prominent risk factor for AD, understanding the molecular changes during aging is likely to provide critical insights into AD pathogenesis. However, studies on the role of miRNAs in aging and AD pathogenesis have only recently been initiated. Identifying miRNAs dysregulated by the aging process in the brain may lead to novel understanding of molecular mechanisms of AD pathogenesis. Here, we identified that miR-186 levels are gradually decreased in cortices of mouse brains during aging. In addition, we demonstrated that miR-186 suppresses ß-site amyloid precursor protein-cleaving enzyme 1 (BACE1) expression by directly targeting the 3'UTR of Bace1 mRNA in neuronal cells. In contrast, inhibition of endogenous miR-186 significantly increased BACE1 levels in neuronal cells. Importantly, miR-186 over-expression significantly decreased Aß level by suppressing BACE1 expression in cells expressing human pathogenic mutant amyloid precursor protein. Taken together, our data demonstrate that miR-186 is a potent negative regulator of BACE1 in neuronal cells and it may be one of the molecular links between brain aging and the increased risk for AD during aging. We identified that miR-186 levels are gradually decreased in mouse cortices during aging. Furthermore, we demonstrated that miR-186 is a novel negative regulator of beta-site amyloid precursor protein-cleaving enzyme 1 (BACE1) expression in neuronal cells. Therefore, we proposed that reduction in miR-186 levels during aging may lead to the up-regulation of BACE1 in the brain, thereby increasing a risk for Alzheimer's disease in aged individuals. Read the Editorial Highlight for this article on page 308.


Asunto(s)
Envejecimiento/metabolismo , Secretasas de la Proteína Precursora del Amiloide/biosíntesis , Secretasas de la Proteína Precursora del Amiloide/genética , Ácido Aspártico Endopeptidasas/biosíntesis , Ácido Aspártico Endopeptidasas/genética , Química Encefálica/genética , MicroARNs/genética , MicroARNs/metabolismo , Regiones no Traducidas 3' , Enfermedad de Alzheimer/metabolismo , Precursor de Proteína beta-Amiloide/biosíntesis , Precursor de Proteína beta-Amiloide/genética , Animales , Secuencia de Bases , Corteza Cerebral/metabolismo , Regulación de la Expresión Génica , Ratones , Ratones Endogámicos C57BL , Datos de Secuencia Molecular , Mutación , Neuronas/metabolismo
13.
J Sci Food Agric ; 96(7): 2433-9, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26243037

RESUMEN

BACKGROUND: Although rice (Oryza sativa L.) is the third largest food crop, relatively fewer studies have been reported on rice geographical origin based on light element isotope ratios in comparison with other foods such as wine, beef, juice, oil and milk. Therefore this study tries to discriminate the geographical origin of the same rice cultivars grown in different Asian countries using the analysis of C, N, O and S stable isotope ratios and chemometrics. RESULTS: The δ(15) NAIR , δ(18) OVSMOW and δ(34) SVCDT values of brown rice were more markedly influenced by geographical origin than was the δ(13) CVPDB value. In particular, the combination of δ(18) OVSMOW and δ(34) SVCDT more efficiently discriminated rice geographical origin than did the remaining combinations. Principal component analysis (PCA) revealed a clear discrimination between different rice geographical origins but not between rice genotypes. In particular, the first components of PCA discriminated rice cultivated in the Philippines from rice cultivated in China and Korea. CONCLUSION: The present findings suggest that analysis of the light element isotope composition combined with chemometrics can be potentially applicable to discriminate rice geographical origin and also may provide a valuable insight into the control of improper or fraudulent labeling regarding the geographical origin of rice worldwide. © 2015 Society of Chemical Industry.


Asunto(s)
Carbono/química , Nitrógeno/química , Oryza/química , Oxígeno/química , Azufre/química , Isótopos de Carbono , China , Isótopos de Nitrógeno , Isótopos de Oxígeno , Filipinas , República de Corea , Isótopos de Azufre
14.
J Exp Bot ; 66(13): 4023-33, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25944928

RESUMEN

The Arabidopsis thaliana genome encodes three RNA-binding proteins (RBPs), UBP1-associated protein 2a (UBA2a), UBA2b, and UBA2c, that contain two RNA-recognition motif (RRM) domains. They play important roles in wounding response and leaf senescence, and are homologs of Vicia faba abscisic-acid-activated protein kinase-interacting protein 1 (VfAKIP1). The potato (Solanum tuberosum) genome encodes at least seven AKIP1-like RBPs. Here, two potato RBPs have been characterized, StUBA2a/b and StUBA2c, that are homologous to VfAKIP1 and Arabidopsis UBA2s. Transient expression of StUBA2s induced a hypersensitive-like cell death phenotype in tobacco leaves, and an RRM-domain deletion assay of StUBA2s revealed that the first RRM domain is crucial for the phenotype. Unlike overexpression of Arabidopsis UBA2s, constitutive expression of StUBA2a/b in Arabidopsis did not cause growth arrest and lethality at the young seedling stage, but induced early leaf senescence. This phenotype was associated with increased expression of defence- and senescence-associated genes, including pathogen-related genes (PR) and a senescence-associated gene (SAG13), and it was aggravated upon flowering and ultimately resulted in a shortened life cycle. Leaf senescence of StUBA2a/b Arabidopsis plants was enhanced under darkness and was accompanied by H2O2 accumulation and altered expression of autophagy-associated genes, which likely cause cellular damage and are proximate causes of the early leaf senescence. Expression of salicylic acid signalling and biosynthetic genes was also upregulated in StUBA2a/b plants. Consistent with the localization of UBA2s-GFPs and VfAKIP1-GFP, soluble-modified GFP-StUBA2s localized in the nucleus within nuclear speckles. StUBA2s potentially can be considered for transgenic approaches to induce potato shoot senescence, which is desirable at harvest.


Asunto(s)
Arabidopsis/citología , Arabidopsis/genética , Hojas de la Planta/citología , Hojas de la Planta/crecimiento & desarrollo , Proteínas de Plantas/metabolismo , Proteínas de Unión al ARN/metabolismo , Solanum tuberosum/metabolismo , Secuencia de Aminoácidos , Autofagia/genética , Muerte Celular , Clonación Molecular , Regulación de la Expresión Génica de las Plantas , Genes de Plantas , Proteínas Fluorescentes Verdes/metabolismo , Peróxido de Hidrógeno/metabolismo , Datos de Secuencia Molecular , Filogenia , Hojas de la Planta/genética , Proteínas de Plantas/química , Proteínas de Plantas/genética , Plantas Modificadas Genéticamente , Proteínas de Unión al ARN/química , Proteínas de Unión al ARN/genética , Solanum tuberosum/genética , Estrés Fisiológico/genética , Fracciones Subcelulares/metabolismo , Nicotiana/genética , Regulación hacia Arriba/genética
15.
Cell Physiol Biochem ; 34(3): 865-72, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25199820

RESUMEN

BACKGROUND/AIMS: The use of tyrosine kinase inhibitors (TKIs) to target active epidermal growth factor receptor (EGFR)-harbouring mutations has been effective in patients with advanced non-small-cell lung cancer (NSCLC). However, the use of TKIs in NSCLS patients with somatic EGFR mutations, particularly T790M, causes drug resistance. Thus, in the present study, we investigated overcoming resistance against the TKI gefitinib by combination treatment with melatonin in H1975 NSCLC cells harbouring the T790M somatic mutation. METHODS: H1975 and HCC827 cells were treated with melatonin in combination with gefitinib, and cell viability, cell cycle progression, apoptosis, and EGFR, AKT, p38, Bcl-2, Bcl-xL, caspase 3 and Bad protein levels were examined. RESULTS: Treatment with melatonin dose-dependently decreased the viability of H1975 cells harbouring the T790M somatic mutation compared to HCC827 cells with an EGFR active mutation. Melatonin-mediated cell death resulted in decreased phosphorylation of EGFR and Akt, leading to attenuated expression of survival proteins, such as Bcl-2, Bcl-xL and survivin, and activated caspase 3 in H1975 cells, but not in HCC827 cells. However, we did not observe a significant change in expression of cell cycle proteins, such as cyclin D, cyclin A, p21 and CDK4 in H1975 cells. Surprisingly, co-treatment of gefitinib with melatonin effectively decreased the viability of H1975 cells, but not HCC827 cells. Moreover, co-treatment of H1975 cells caused consistent down-regulation of EGFR phosphorylation and induced apoptosis compared to treatment with gefitinib or melatonin alone. CONCLUSIONS: Our findings demonstrate that melatonin acts as a potent chemotherapeutic agent by sensitising to gefitinib TKI-resistant H1975 cells that harbour a EGFR T790M mutation.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/patología , Receptores ErbB/genética , Neoplasias Pulmonares/patología , Melatonina/farmacología , Mutación , Quinazolinas/uso terapéutico , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/genética , División Celular/efectos de los fármacos , Línea Celular Tumoral , Receptores ErbB/metabolismo , Citometría de Flujo , Gefitinib , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Fosforilación
16.
Chemphyschem ; 15(10): 1971-82, 2014 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-24953300

RESUMEN

Impressive developments have been made in the past a few years toward the establishment of Na-ion batteries as next-generation energy-storage devices and replacements for Li-ion batteries. Na-based cells have attracted increasing attention owing to low production costs due to abundant sodium resources. However, applications of Na-ion batteries are limited to large-scale energy-storage systems because of their lower energy density compared to Li-ion batteries and their potential safety problems. Recently, Na-metal cells such as Na-metal halide and Na-air batteries have been considered to be promising for use in electric vehicles owing to good safety and high energy density, although less attention is focused on Na-metal cells than on Na-ion cells. This Minireview provides an overview of the fundamentals and recent progress in the fields of Na-metal halide and Na-air batteries, with the aim of providing a better understanding of new electrochemical systems.

17.
Inorg Chem ; 53(21): 11367-76, 2014 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-25333939

RESUMEN

Multifunctional metal chelators that can modulate the amyloid ß (Aß) peptide aggregation and its interaction with metal ions such as copper and zinc hold considerable promise as therapeutic agents for Alzheimer's disease (AD). However, specific rather than systemic metal chelation by these compounds is needed in order to limit any side effects. Reported herein are two novel small bifunctional chelators, 2-[2-hydroxy-4-(diethylamino)phenyl]benzothiazole (L1) and 2-(2-hydroxy-3-methoxyphenyl)benzothiazole (L2), in which the metal-binding donor atoms are integrated within a molecular framework derived from the amyloid-binding fluorescent dye thioflavin T (ThT). The metal-binding properties of L1 and L2 were probed by pH spectrophotometric titrations to determine their pKa values and the corresponding metal complex stability constants, and the isolated metal complexes were structurally characterized. The amyloid-fibril-binding properties of L1 and L2 were investigated by fluorescence titrations and ThT competition assays. Interestingly, L1 and L2 do not lead to the formation of neurotoxic Aß42 oligomers in the presence or absence of metal ions, as observed by native gel electrophoresis, Western blotting, and transmission electron microscopy. In addition, L1 and L2 were able to reduce the cell toxicity of preformed Aß42 oligomers and of the copper-stabilized Aß42 oligomers. Given their ability to reduce the toxicity of soluble Aß42 and Cu-Aß42 species, L1 and L2 are promising lead compounds for the development of chemical agents that can control the neurotoxicity of soluble Aß42 species in AD.


Asunto(s)
Péptidos beta-Amiloides/química , Péptidos beta-Amiloides/toxicidad , Quelantes/química , Quelantes/farmacología , Agregado de Proteínas/efectos de los fármacos , Animales , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Quelantes/síntesis química , Clioquinol/química , Clioquinol/farmacología , Cristalografía por Rayos X , Ratones , Modelos Moleculares , Estructura Molecular , Agregación Patológica de Proteínas
18.
FEBS J ; 2024 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-38715400

RESUMEN

Tauopathies exhibit a characteristic accumulation of misfolded tau aggregates in the brain. Tau pathology shows disease-specific spatiotemporal propagation through intercellular transmission, which is closely correlated with the progression of clinical manifestations. Therefore, identifying molecular mechanisms that prevent tau propagation is critical for developing therapeutic strategies for tauopathies. The various innate immune receptors, such as complement receptor 3 (CR3) and complement receptor 4 (CR4), have been reported to play a critical role in the clearance of various extracellular toxic molecules by microglia. However, their role in tau clearance has not been studied yet. In the present study, we investigated the role of CR3 and CR4 in regulating extracellular tau clearance. We found that CR4 selectively binds to tau fibrils but not to tau monomers, whereas CR3 does not bind to either of them. Inhibiting CR4, but not CR3, significantly reduces the uptake of tau fibrils by BV2 cells and primary microglia. By contrast, inhibiting CR4 has no effect on the uptake of tau monomers by BV2 cells. Furthermore, inhibiting CR4 suppresses the clearance of extracellular tau fibrils, leading to more seed-competent tau fibrils remaining in the extracellular space relative to control samples. We also provide evidence that the expression of CR4 is upregulated in the brains of human Alzheimer's disease patients and the PS19 mouse model of tauopathy. Taken together, our data strongly support that CR4 is a previously undescribed receptor for the clearance of tau fibrils in microglia and may represent a novel therapeutic target for tauopathy.

19.
Biomolecules ; 14(3)2024 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-38540798

RESUMEN

Although granule cell dispersion (GCD) in the hippocampus is known to be an important feature associated with epileptic seizures in temporal lobe epilepsy (TLE), the endogenous molecules that regulate GCD are largely unknown. In the present study, we have examined whether there is any change in AEG-1 expression in the hippocampus of a kainic acid (KA)-induced mouse model of TLE. In addition, we have investigated whether the modulation of astrocyte elevated gene-1 (AEG-1) expression in the dentate gyrus (DG) by intracranial injection of adeno-associated virus 1 (AAV1) influences pathological phenotypes such as GCD formation and seizure susceptibility in a KA-treated mouse. We have identified that the protein expression of AEG-1 is upregulated in the DG of a KA-induced mouse model of TLE. We further demonstrated that AEG-1 upregulation by AAV1 delivery in the DG-induced anticonvulsant activities such as the delay of seizure onset and inhibition of spontaneous recurrent seizures (SRS) through GCD suppression in the mouse model of TLE, while the inhibition of AEG-1 expression increased susceptibility to seizures. The present observations suggest that AEG-1 is a potent regulator of GCD formation and seizure development associated with TLE, and the significant induction of AEG-1 in the DG may have therapeutic potential against epilepsy.


Asunto(s)
Epilepsia del Lóbulo Temporal , Epilepsia , Animales , Ratones , Astrocitos/metabolismo , Giro Dentado/metabolismo , Epilepsia/metabolismo , Epilepsia del Lóbulo Temporal/inducido químicamente , Epilepsia del Lóbulo Temporal/genética , Epilepsia del Lóbulo Temporal/tratamiento farmacológico , Hipocampo/metabolismo , Ácido Kaínico/efectos adversos , Ácido Kaínico/metabolismo , Convulsiones/inducido químicamente , Convulsiones/genética , Convulsiones/metabolismo
20.
J Biol Chem ; 287(9): 6628-41, 2012 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-22219196

RESUMEN

A loss-of-function mutation in the gene parkin causes a common neurodegenerative disease that may be caused by mitochondrial dysfunction. Glutathione S-transferase Omega (GSTO) is involved in cell defense mechanisms, but little is known about the role of GSTO in the progression of Parkinson disease. Here, we report that restoration of Drosophila GSTO1 (DmGSTO1), which is down-regulated in parkin mutants, alleviates some of the parkin pathogenic phenotypes and that the loss of DmGSTO1 function enhances parkin mutant phenotypes. We further identified the ATP synthase ß subunit as a novel in vivo target of DmGSTO1. We found that glutathionylation of the ATP synthase ß subunit is rescued by DmGSTO1 and that the expression of DmGSTO1 partially restores the activity and assembly of the mitochondrial F(1)F(0)-ATP synthase in parkin mutants. Our results suggest a novel mechanism for the protective role of DmGSTO1 in parkin mutants, through the regulation of ATP synthase activity, and provide insight into potential therapies for Parkinson disease neurodegeneration.


Asunto(s)
Proteínas de Drosophila/metabolismo , Glutatión Transferasa/metabolismo , Degeneración Nerviosa/enzimología , Trastornos Parkinsonianos/enzimología , Ubiquitina-Proteína Ligasas/genética , Animales , Modelos Animales de Enfermedad , Proteínas de Drosophila/genética , Drosophila melanogaster , Glutatión Transferasa/genética , Herbicidas/toxicidad , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Masculino , ATPasas de Translocación de Protón Mitocondriales/metabolismo , Mutagénesis Sitio-Dirigida , Degeneración Nerviosa/inducido químicamente , Estrés Oxidativo/efectos de los fármacos , Estrés Oxidativo/fisiología , Paraquat/toxicidad , Fenotipo , Transducción de Señal/fisiología , Tubulina (Proteína)/metabolismo , Respuesta de Proteína Desplegada/fisiología
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