Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 6.286
Filtrar
1.
Lancet Neurol ; 19(10): 872-878, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32949547

RESUMO

Studies in experimental animals show transmissibility of amyloidogenic proteins associated with prion diseases, Alzheimer's disease, Parkinson's disease, and other neurodegenerative diseases. Although these data raise potential concerns for public health, convincing evidence for human iatrogenic transmission only exists for prions and amyloid ß after systemic injections of contaminated growth hormone extracts or dura mater grafts derived from cadavers. Even though these procedures are now obsolete, some reports raise the possibility of iatrogenic transmission of amyloid ß through putatively contaminated neurosurgical equipment. Iatrogenic transmission of amyloid ß might lead to amyloid deposition in the brain parenchyma and blood vessel walls, potentially resulting in cerebral amyloid angiopathy after several decades. Cerebral amyloid angiopathy can cause life-threatening brain haemorrhages; yet, there is no proof that the transmission of amyloid ß can also lead to Alzheimer's dementia. Large, long-term epidemiological studies and sensitive, cost-efficient tools to detect amyloid are needed to better understand any potential routes of amyloid ß transmission and to clarify whether other similar proteopathic seeds, such as tau or α-synuclein, can also be transferred iatrogenically.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Doenças Neurodegenerativas/metabolismo , Vigilância da População , Doença de Alzheimer/etiologia , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/toxicidade , Animais , Síndrome de Creutzfeldt-Jakob/metabolismo , Síndrome de Creutzfeldt-Jakob/patologia , Síndrome de Creutzfeldt-Jakob/transmissão , Humanos , Doenças Neurodegenerativas/etiologia , Doenças Neurodegenerativas/patologia , Doença de Parkinson/etiologia , Doença de Parkinson/metabolismo , Doença de Parkinson/patologia , Fatores de Risco
2.
PLoS One ; 15(8): e0233247, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32857759

RESUMO

Poly(glycine-alanine) (polyGA) is one of the polydipeptides expressed in Frontotemporal Dementia and/or Amyotrophic Lateral Sclerosis 1 caused by C9ORF72 mutations and accumulates as inclusion bodies in the brain of patients. Superficially these inclusions are similar to those formed by polyglutamine (polyQ)-expanded Huntingtin exon 1 (Httex1) in Huntington's disease. Both have been reported to form an amyloid-like structure suggesting they might aggregate via similar mechanisms and therefore recruit the same repertoire of endogenous proteins. When co-expressed in the same cell, polyGA101 and Httex1(Q97) inclusions adopted immiscible phases suggesting different endogenous proteins would be enriched. Proteomic analyses identified 822 proteins in the inclusions. Only 7 were specific to polyGA and 4 specific to Httex1(Q97). Quantitation demonstrated distinct enrichment patterns for the proteins not specific to each inclusion type (up to ~8-fold normalized to total mass). The proteasome, microtubules, TriC chaperones, and translational machinery were enriched in polyGA aggregates, whereas Dnaj chaperones, nuclear envelope and RNA splicing proteins were enriched in Httex1(Q97) aggregates. Both structures revealed a collection of folding and degradation machinery including proteins in the Httex1(Q97) aggregates that are risk factors for other neurodegenerative diseases involving protein aggregation when mutated, which suggests a convergence point in the pathomechanisms of these diseases.


Assuntos
Corpos de Inclusão/metabolismo , Peptídeos/metabolismo , Proteínas/metabolismo , Animais , Proteína C9orf72/genética , Proteína C9orf72/metabolismo , Linhagem Celular , Éxons , Humanos , Proteína Huntingtina/genética , Proteína Huntingtina/metabolismo , Corpos de Inclusão/genética , Corpos de Inclusão/patologia , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Camundongos , Microscopia Confocal , Mutação , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/metabolismo , Doenças Neurodegenerativas/patologia , Peptídeos/genética , Agregação Patológica de Proteínas/genética , Agregação Patológica de Proteínas/metabolismo , Agregação Patológica de Proteínas/patologia , Proteínas/genética , Proteólise , Proteoma/genética , Proteoma/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Fatores de Risco , Solubilidade
3.
Cells ; 9(9)2020 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-32859053

RESUMO

Extracellular vesicles are a heterogeneous group of cell-derived membranous structures comprising of exosomes, apoptotic bodies, and microvesicles. Of the extracellular vesicles, exosomes are the most widely sorted and extensively explored for their contents and function. The size of the nanovesicular structures (exosomes) range from 30 to 140 nm and are present in various biological fluids such as saliva, plasma, urine etc. These cargo-laden extracellular vesicles arise from endosome-derived multivesicular bodies and are known to carry proteins and nucleic acids. Exosomes are involved in multiple physiological and pathological processes, including cellular senescence. Exosomes mediate signaling crosstalk and play a critical role in cell-cell communications. Exosomes have evolved as potential biomarkers for aging-related diseases. Aging, a physiological process, involves a progressive decline of function of organs with a loss of homeostasis and increasing probability of illness and death. The review focuses on the classic view of exosome biogenesis, biology, and age-associated changes. Owing to their ability to transport biological information among cells, the review also discusses the interplay of senescent cell-derived exosomes with the aging process, including the susceptibility of the aging population to COVID-19 infections.


Assuntos
Envelhecimento/metabolismo , Doenças Cardiovasculares/metabolismo , Comunicação Celular , Senescência Celular , Infecções por Coronavirus/metabolismo , Diabetes Mellitus/metabolismo , Exossomos/metabolismo , Vesículas Extracelulares/metabolismo , Doenças Neurodegenerativas/metabolismo , Pneumonia Viral/metabolismo , Idoso , Idoso de 80 Anos ou mais , Animais , Betacoronavirus , Biomarcadores/metabolismo , Infecções por Coronavirus/virologia , Humanos , Camundongos , Pandemias , Pneumonia Viral/virologia
4.
PLoS One ; 15(8): e0235810, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32810171

RESUMO

Anomia is common in Primary Progressive Aphasia (PPA), and there is considerable evidence that semantic problems (as opposed to impaired access to output word phonology) exist in many PPA individuals irrespective of their strict subtype, including a loss of representations from semantic memory, which is typical for people with the semantic variant of PPA. In this manuscript we present a straightforward novel clinical algorithm that quantifies this degree of semantic storage impairment. We sought to produce an algorithm by employing tasks that would measure key elements of semantic storage loss: a) whether an unrecalled name could be retrieved with cues; b) if performance for items was consistent across tasks; and c) the degree to which a participant's performance was related to general severity of cognitive impairment rather than semantic loss. More specifically, these tasks were given to 28 individuals with PPA (12 participants had a clinical diagnosis of atypical Alzheimer's Disease with the logopenic variant of PPA; the remaining 16 participants received a clinical diagnosis of Frontotemporal dementia (11 were classified as the non-fluent variant of PPA and five were the semantic variant of PPA). Scores from these tasks produced a single omnibus semantic memory storage loss score (SSL score) for each person that ranged from 0.0 to 1.0, with scores closer to 0 more indicative of semantic storage loss. Indeed, supporting the hypothesis that our scores measure the degree of semantic storage loss, we found participants with the semantic variant of PPA had the lowest scores, and SSL scores could predict the degree of hypometabolism in the anterior temporal lobe; even when only people with the logopenic variant of PPA were examined. Thus, these scores show promise quantitating the degree of a person's semantic representation loss.


Assuntos
Afasia Primária Progressiva/fisiopatologia , Doenças Neurodegenerativas/fisiopatologia , Semântica , Lobo Temporal/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/complicações , Doença de Alzheimer/metabolismo , Doença de Alzheimer/fisiopatologia , Afasia Primária Progressiva/etiologia , Afasia Primária Progressiva/metabolismo , Feminino , Demência Frontotemporal/complicações , Demência Frontotemporal/metabolismo , Demência Frontotemporal/fisiopatologia , Humanos , Masculino , Doenças Neurodegenerativas/complicações , Doenças Neurodegenerativas/metabolismo , Testes Neuropsicológicos , Tomografia por Emissão de Pósitrons , Lobo Temporal/metabolismo
5.
Proc Natl Acad Sci U S A ; 117(31): 18810-18821, 2020 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-32690710

RESUMO

In the central nervous system, glycogen-derived bioenergetic resources in astrocytes help promote tissue survival in response to focal neuronal stress. However, our understanding of the extent to which these resources are mobilized and utilized during neurodegeneration, especially in nearby regions that are not actively degenerating, remains incomplete. Here we modeled neurodegeneration in glaucoma, the world's leading cause of irreversible blindness, and measured how metabolites mobilize through astrocyte gap junctions composed of connexin 43 (Cx43). We elevated intraocular pressure in one eye and determined how astrocyte-derived metabolites in the contralateral optic projection responded. Remarkably, astrocyte networks expand and redistribute metabolites along distances even 10 mm in length, donating resources from the unstressed to the stressed projection in response to intraocular pressure elevation. While resource donation improves axon function and visual acuity in the directly stressed region, it renders the donating tissue susceptible to bioenergetic, structural, and physiological degradation. Intriguingly, when both projections are stressed in a WT animal, axon function and visual acuity equilibrate between the two projections even when each projection is stressed for a different length of time. This equilibration does not occur when Cx43 is not present. Thus, Cx43-mediated astrocyte metabolic networks serve as an endogenous mechanism used to mitigate bioenergetic stress and distribute the impact of neurodegenerative disease processes. Redistribution ultimately renders the donating optic nerve vulnerable to further metabolic stress, which could explain why local neurodegeneration does not remain confined, but eventually impacts healthy regions of the brain more broadly.


Assuntos
Astrócitos , Glaucoma/metabolismo , Doenças Neurodegenerativas/metabolismo , Animais , Astrócitos/metabolismo , Astrócitos/fisiologia , Conexina 43/genética , Conexina 43/metabolismo , Feminino , Junções Comunicantes/metabolismo , Pressão Intraocular/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos
6.
Proc Natl Acad Sci U S A ; 117(29): 17296-17307, 2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32631998

RESUMO

Mutations in leucine-rich repeat kinase 2 (LRRK2) are the most common cause of late-onset, autosomal-dominant familial Parkinson's disease (PD). LRRK2 functions as both a kinase and GTPase, and PD-linked mutations are known to influence both enzymatic activities. While PD-linked LRRK2 mutations can commonly induce neuronal damage in culture models, the mechanisms underlying these pathogenic effects remain uncertain. Rodent models containing familial LRRK2 mutations often lack robust PD-like neurodegenerative phenotypes. Here, we develop a robust preclinical model of PD in adult rats induced by the brain delivery of recombinant adenoviral vectors with neuronal-specific expression of human LRRK2 harboring the most common G2019S mutation. In this model, G2019S LRRK2 induces the robust degeneration of substantia nigra dopaminergic neurons, a pathological hallmark of PD. Introduction of a stable kinase-inactive mutation or administration of the selective kinase inhibitor, PF-360, attenuates neurodegeneration induced by G2019S LRRK2. Neuroprotection provided by pharmacological kinase inhibition is mediated by an unusual mechanism involving the robust destabilization of human LRRK2 protein in the brain relative to endogenous LRRK2. Our study further demonstrates that G2019S LRRK2-induced dopaminergic neurodegeneration critically requires normal GTPase activity, as hypothesis-testing mutations that increase GTP hydrolysis or impair GTP-binding activity provide neuroprotection although via distinct mechanisms. Taken together, our data demonstrate that G2019S LRRK2 induces neurodegeneration in vivo via a mechanism that is dependent on kinase and GTPase activity. Our study provides a robust rodent preclinical model of LRRK2-linked PD and nominates kinase inhibition and modulation of GTPase activity as promising disease-modifying therapeutic targets.


Assuntos
Neurônios Dopaminérgicos/metabolismo , GTP Fosfo-Hidrolases/metabolismo , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/metabolismo , Doença de Parkinson/metabolismo , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Linhagem Celular , Modelos Animais de Doenças , Dopamina/metabolismo , Feminino , Humanos , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/genética , Camundongos , Camundongos Knockout , Mutação , Doenças Neurodegenerativas/tratamento farmacológico , Doenças Neurodegenerativas/metabolismo , Doença de Parkinson/patologia , Fenótipo , Projetos Piloto , Inibidores de Proteínas Quinases/farmacologia , Ratos , Ratos Wistar , Substância Negra
7.
Proc Natl Acad Sci U S A ; 117(29): 17269-17277, 2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32611818

RESUMO

Traumatic brain injury (TBI) is the strongest environmental risk factor for the accelerated development of neurodegenerative diseases. There are currently no therapeutics to address this due to lack of insight into mechanisms of injury progression, which are challenging to study in mammalian models. Here, we have developed and extensively characterized a head-specific approach to TBI in Drosophila, a powerful genetic system that shares many conserved genes and pathways with humans. The Drosophila TBI (dTBI) device inflicts mild, moderate, or severe brain trauma by precise compression of the head using a piezoelectric actuator. Head-injured animals display features characteristic of mammalian TBI, including severity-dependent ataxia, life span reduction, and brain degeneration. Severe dTBI is associated with cognitive decline and transient glial dysfunction, and stimulates antioxidant, proteasome, and chaperone activity. Moreover, genetic or environmental augmentation of the stress response protects from severe dTBI-induced brain degeneration and life span deficits. Together, these findings present a tunable, head-specific approach for TBI in Drosophila that recapitulates mammalian injury phenotypes and underscores the ability of the stress response to mitigate TBI-induced brain degeneration.


Assuntos
Lesões Encefálicas Traumáticas/metabolismo , Encéfalo/metabolismo , Drosophila/fisiologia , Neuroglia/metabolismo , Animais , Comportamento Animal , Lesões Encefálicas Traumáticas/diagnóstico por imagem , Lesões Encefálicas Traumáticas/patologia , Modelos Animais de Doenças , Cabeça , Humanos , Masculino , Doenças Neurodegenerativas/metabolismo , Neuroglia/patologia , Estresse Fisiológico
8.
Mol Cell ; 79(3): 521-534.e15, 2020 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-32592681

RESUMO

Genome-wide mapping of chromatin interactions at high resolution remains experimentally and computationally challenging. Here we used a low-input "easy Hi-C" protocol to map the 3D genome architecture in human neurogenesis and brain tissues and also demonstrated that a rigorous Hi-C bias-correction pipeline (HiCorr) can significantly improve the sensitivity and robustness of Hi-C loop identification at sub-TAD level, especially the enhancer-promoter (E-P) interactions. We used HiCorr to compare the high-resolution maps of chromatin interactions from 10 tissue or cell types with a focus on neurogenesis and brain tissues. We found that dynamic chromatin loops are better hallmarks for cellular differentiation than compartment switching. HiCorr allowed direct observation of cell-type- and differentiation-specific E-P aggregates spanning large neighborhoods, suggesting a mechanism that stabilizes enhancer contacts during development. Interestingly, we concluded that Hi-C loop outperforms eQTL in explaining neurological GWAS results, revealing a unique value of high-resolution 3D genome maps in elucidating the disease etiology.


Assuntos
Cromatina/metabolismo , Elementos Facilitadores Genéticos , Regulação da Expressão Gênica no Desenvolvimento , Redes Reguladoras de Genes , Genoma Humano , Neurogênese/genética , Regiões Promotoras Genéticas , Adulto , Linhagem Celular , Cérebro/citologia , Cérebro/crescimento & desenvolvimento , Cérebro/metabolismo , Cromatina/ultraestrutura , Mapeamento Cromossômico , Feto , Histonas/genética , Histonas/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Proteínas do Tecido Nervoso/classificação , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/metabolismo , Doenças Neurodegenerativas/patologia , Neurônios/citologia , Neurônios/metabolismo , Lobo Temporal/citologia , Lobo Temporal/crescimento & desenvolvimento , Lobo Temporal/metabolismo , Fatores de Transcrição/classificação , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
9.
Proc Natl Acad Sci U S A ; 117(25): 14220-14230, 2020 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-32513741

RESUMO

Because raising cAMP enhances 26S proteasome activity and the degradation of cell proteins, including the selective breakdown of misfolded proteins, we investigated whether agents that raise cGMP may also regulate protein degradation. Treating various cell lines with inhibitors of phosphodiesterase 5 or stimulators of soluble guanylyl cyclase rapidly enhanced multiple proteasome activities and cellular levels of ubiquitinated proteins by activating protein kinase G (PKG). PKG stimulated purified 26S proteasomes by phosphorylating a different 26S component than is modified by protein kinase A. In cells and cell extracts, raising cGMP also enhanced within minutes ubiquitin conjugation to cell proteins. Raising cGMP, like raising cAMP, stimulated the degradation of short-lived cell proteins, but unlike cAMP, also markedly increased proteasomal degradation of long-lived proteins (the bulk of cell proteins) without affecting lysosomal proteolysis. We also tested if raising cGMP, like cAMP, can promote the degradation of mutant proteins that cause neurodegenerative diseases. Treating zebrafish models of tauopathies or Huntington's disease with a PDE5 inhibitor reduced the levels of the mutant huntingtin and tau proteins, cell death, and the resulting morphological abnormalities. Thus, PKG rapidly activates cytosolic proteasomes, protein ubiquitination, and overall protein degradation, and agents that raise cGMP may help combat the progression of neurodegenerative diseases.


Assuntos
Proteínas Quinases Dependentes de GMP Cíclico/metabolismo , GMP Cíclico/metabolismo , Doenças Neurodegenerativas/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteólise , Animais , Animais Geneticamente Modificados , AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Modelos Animais de Doenças , Humanos , Fosforilação , Tauopatias , Ubiquitina/metabolismo , Proteínas Ubiquitinadas/metabolismo , Ubiquitinação , Peixe-Zebra , Proteínas tau/metabolismo
10.
ACS Chem Neurosci ; 11(13): 1887-1899, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32491829

RESUMO

The coronavirus disease-19 (COVID-19) pandemic has emerged as one of the major outbreaks to be mentioned in history in coming times. Like severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS), severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a respiratory virus infecting the lungs with fever, dry cough, and acute pneumonia being the major symptoms. It infects epithelial cells expressing angiotensin converting enzyme 2 (ACE2) receptor, which is crucial for viral entry. Based on evolving clinical evidence, it is now unfitting to label SARS-CoV-2 as just a respiratory virus, as lately there are various reports that substantiate its pathogenicity in other organs of the body, including brain. In this review, we discuss the epidemiology of SARS-CoV-2 in comparison to SARS and MERS along with possibilities of viral entry into central nervous system (CNS) tissues. The review provides detailed information about the virulence, epidemiology, and insights into molecular pathways involved in the infectivity of the SARS-CoV-2 virus, along with an in-depth view of current concepts about the neurological significance of the SARS-CoV-2 virus and its neuropathological competence. The review also touches upon our current understanding of placental transmission of SARS-CoV-2, an important aspect of vertical transmission. Furthermore, the review provides a current update on strategies that have been used, are being used, or are under trial for treating the disease.


Assuntos
Betacoronavirus/metabolismo , Encéfalo/metabolismo , Infecções por Coronavirus/metabolismo , Doenças Neurodegenerativas/metabolismo , Pneumonia Viral/metabolismo , Encéfalo/patologia , Encéfalo/virologia , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/patologia , Humanos , Doenças Neurodegenerativas/patologia , Doenças Neurodegenerativas/virologia , Pandemias , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/epidemiologia , Pneumonia Viral/patologia , Síndrome Respiratória Aguda Grave/epidemiologia , Síndrome Respiratória Aguda Grave/metabolismo , Síndrome Respiratória Aguda Grave/patologia
11.
Nat Commun ; 11(1): 2993, 2020 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-32532970

RESUMO

The accumulation of protein aggregates is involved in the onset of many neurodegenerative diseases. Aggrephagy is a selective type of autophagy that counteracts neurodegeneration by degrading such aggregates. In this study, we found that LC3C cooperates with lysosomal TECPR1 to promote the degradation of disease-related protein aggregates in neural stem cells. The N-terminal WD-repeat domain of TECPR1 selectively binds LC3C which decorates matured autophagosomes. The interaction of LC3C and TECPR1 promotes the recruitment of autophagosomes to lysosomes for degradation. Augmented expression of TECPR1 in neural stem cells reduces the number of protein aggregates by promoting their autophagic clearance, whereas knockdown of LC3C inhibits aggrephagy. The PH domain of TECPR1 selectively interacts with PtdIns(4)P to target TECPR1 to PtdIns(4)P containing lysosomes. Exchanging the PH against a tandem-FYVE domain targets TECPR1 ectopically to endosomes. This leads to an accumulation of LC3C autophagosomes at endosomes and prevents their delivery to lysosomes.


Assuntos
Autofagossomos/metabolismo , Lisossomos/metabolismo , Proteínas de Membrana/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Células-Tronco Neurais/metabolismo , Autofagossomos/ultraestrutura , Autofagia/genética , Sistemas CRISPR-Cas/genética , Linhagem Celular , Endossomos/metabolismo , Células HeLa , Humanos , Lisossomos/ultraestrutura , Proteínas de Membrana/química , Proteínas de Membrana/genética , Microscopia Confocal , Microscopia Imunoeletrônica , Proteínas Associadas aos Microtúbulos/química , Proteínas Associadas aos Microtúbulos/genética , Células-Tronco Neurais/citologia , Doenças Neurodegenerativas/metabolismo , Agregados Proteicos , Agregação Patológica de Proteínas , Ligação Proteica , Transporte Proteico , Proteólise , Interferência de RNA
12.
Gene ; 756: 144874, 2020 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-32554047

RESUMO

ApoD is a 25 to 30 kDa glycosylated protein, member of the lipocalin superfamily. As a transporter of several small hydrophobic molecules, its known biological functions are mostly associated to lipid metabolism and neuroprotection. ApoD is a multi-ligand, multi-function protein that is involved lipid trafficking, food intake, inflammation, antioxidative response and development and in different types of cancers. An important aspect of ApoD's role in lipid metabolism appears to involve the transport of arachidonic acid, and the modulation of eicosanoid production and delivery in metabolic tissues. ApoD expression in metabolic tissues has been associated positively and negatively with insulin sensitivity and glucose homeostasis in a tissue dependent manner. ApoD levels rise considerably in association with aging and neuropathologies such as Alzheimer's disease, stroke, meningoencephalitis, moto-neuron disease, multiple sclerosis, schizophrenia and Parkinson's disease. ApoD is also modulated in several animal models of nervous system injury/pathology.


Assuntos
Apolipoproteínas D/metabolismo , Animais , Apolipoproteínas D/química , Apolipoproteínas D/genética , Desenvolvimento Embrionário , Humanos , Neoplasias/metabolismo , Sistema Nervoso/metabolismo , Doenças Neurodegenerativas/metabolismo , Especificidade de Órgãos
13.
Neuron ; 106(6): 899-911, 2020 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-32553207

RESUMO

In recent years, the nuclear pore complex (NPC) has emerged as a key player in genome regulation and cellular homeostasis. New discoveries have revealed that the NPC has multiple cellular functions besides mediating the molecular exchange between the nucleus and the cytoplasm. In this review, we discuss non-transport aspects of the NPC focusing on the NPC-genome interaction, the extreme longevity of the NPC proteins, and NPC dysfunction in age-related diseases. The examples summarized herein demonstrate that the NPC, which first evolved to enable the biochemical communication between the nucleus and the cytoplasm, now doubles as the gatekeeper of cellular identity and aging.


Assuntos
Envelhecimento/metabolismo , Esclerose Amiotrófica Lateral/metabolismo , Diferenciação Celular , Regulação da Expressão Gênica , Complexo de Proteínas Formadoras de Poros Nucleares/metabolismo , Poro Nuclear/metabolismo , Transporte Ativo do Núcleo Celular , Envelhecimento/genética , Senilidade Prematura/genética , Senilidade Prematura/metabolismo , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Esclerose Amiotrófica Lateral/genética , Animais , Proteína de Ligação a CREB/metabolismo , Senescência Celular , Genoma , Humanos , Doença de Huntington/genética , Doença de Huntington/metabolismo , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/metabolismo , Poro Nuclear/genética , Complexo de Proteínas Formadoras de Poros Nucleares/genética
14.
Life Sci ; 256: 117914, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32512010

RESUMO

Hyperglycemia and oxidative stress are the primary stressors that elicit mitochondria specific cell stress in diabetes. Here we hypothesized that elevated level of ROS in high glucose (HG) environment, trigger mitochondrial stress by damaging mitochondrial DNA (mtDNA), altering inflammatory mediators, and neurodegenerative markers via stress signalling pathway in retinal ganglion cells (RGC-5). Mechanistically, our findings illustrated that the HG environment increases the ROS production in retinal cells leading to the disruption of antioxidant defence mechanism, and altering mitochondrial machinery such as an increase in loss of mitochondrial membrane potential (ΔΨm), increase in mitochondrial mass, and increase in mtDNA fragmentation. Furthermore, fragmented mtDNA escape from mitochondria into the cytosol, where it engaged with cyclic GMP-AMP synthase (cGAS) and stimulator of IFN gene (STING) phosphorylation and activate interferon regulatory factor 3 (IRF3) via ERK1/2-Akt-tuberin-mTOR dependent pathways. Our results further indicate that siRNA-mediated gene silencing of tuberin suppresses the strong downregulation of tuberin-mTOR-IRF3 activation. HG environment resulted in activation of IRF3, coinciding with the increased expression of inflammatory mediators and neurodegenerative markers. Pre-treatment of N-acetyl-l-cysteine (NAC) or ERK1/2 or phosphoinositide3-kinase (PI3-K)/Akt inhibitors in RGC-5 cells significantly reduced the HG-induced IRF3 expression and declined the expression of neurodegenerative markers. Collectively, our results demonstrates that HG-induced over production of ROS, disrupts the antioxidant defence mechanism and mitochondrial dysfunction, leading to alterations of inflammatory mediators and neurodegenerative markers through the ERK1/2-Akt-tuberin-mTOR dependent signalling pathway in RGC-5 cells.


Assuntos
Inibidores Enzimáticos/metabolismo , Glucose/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Células Ganglionares da Retina/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Proteína 2 do Complexo Esclerose Tuberosa/metabolismo , Acetilcisteína/metabolismo , Animais , DNA Mitocondrial , Regulação da Expressão Gênica , Células Endoteliais da Veia Umbilical Humana , Humanos , Hiperglicemia/metabolismo , Inflamação/metabolismo , Fator Regulador 3 de Interferon/genética , Fator Regulador 3 de Interferon/metabolismo , Potencial da Membrana Mitocondrial , Camundongos , Mitocôndrias/metabolismo , NADPH Oxidases/metabolismo , Doenças Neurodegenerativas/metabolismo , Estresse Oxidativo , RNA Interferente Pequeno/metabolismo , Transdução de Sinais
15.
Nat Commun ; 11(1): 2146, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32358564

RESUMO

Mitochondria contribute to shape intraneuronal Ca2+ signals. Excessive Ca2+ taken up by mitochondria could lead to cell death. Amyloid beta (Aß) causes cytosolic Ca2+ overload, but the effects of Aß on mitochondrial Ca2+ levels in Alzheimer's disease (AD) remain unclear. Using a ratiometric Ca2+ indicator targeted to neuronal mitochondria and intravital multiphoton microscopy, we find increased mitochondrial Ca2+ levels associated with plaque deposition and neuronal death in a transgenic mouse model of cerebral ß-amyloidosis. Naturally secreted soluble Aß applied onto the healthy brain increases Ca2+ concentration in mitochondria, which is prevented by blockage of the mitochondrial calcium uniporter. RNA-sequencing from post-mortem AD human brains shows downregulation in the expression of mitochondrial influx Ca2+ transporter genes, but upregulation in the genes related to mitochondrial Ca2+ efflux pathways, suggesting a counteracting effect to avoid Ca2+ overload. We propose lowering neuronal mitochondrial Ca2+ by inhibiting the mitochondrial Ca2+ uniporter as a novel potential therapeutic target against AD.


Assuntos
Doença de Alzheimer/metabolismo , Encéfalo/metabolismo , Cálcio/metabolismo , Mitocôndrias/metabolismo , Doenças Neurodegenerativas/metabolismo , Neurônios/citologia , Neurônios/metabolismo , Animais , Western Blotting , Células Cultivadas , Citosol/metabolismo , Imuno-Histoquímica , Masculino , Potencial da Membrana Mitocondrial/fisiologia , Camundongos , Camundongos Endogâmicos C57BL
16.
Mol Pharmacol ; 98(1): 13-22, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32350120

RESUMO

Several reports have been published recently demonstrating a beneficial effect of epidermal growth factor receptor (EGFR) inhibitors in improving pathologic and behavioral conditions in neurodegenerative diseases (NDDs) such as Alzheimer's disease and Amyotrophic Lateral Sclerosis (ALS) as well as the brain and spinal cord injuries (SCI). Despite successful therapeutic effects of EGFR inhibition in these pathologic conditions, there is still no report of proof-of-concept studies in well-characterized animal models using recently developed blood-brain barrier (BBB)-penetrating EGFR inhibitors, which is due to previous conflicting reports concerning the level of EGFR or activated EGFR in normal and pathologic conditions that caused target engagement to be a concern in any future EGFR inhibition therapy. In this review, the level of EGFR expression and activation in the developing central nervous system (CNS) compared with the adult CNS will be explained as well as how neuronal injury or pathologic conditions, especially inflammation and amyloid fibrils, induce reactive astrocytes leading to an increase in the expression and activation of EGFR and, finally, neurodegeneration. Furthermore, in this review, we will discuss two main molecular mechanisms that can be proposed as the neuroprotective effects of EGFR inhibition in these pathologic conditions. We will also review the recent advances in the development of BBB-penetrating EGFR inhibitors in cancer therapy, which may eventually be repositioned for NDDs and SCI therapy in the future. SIGNIFICANCE STATEMENT: Based on the lessons from the applications of EGFR inhibitors in oncology, it is concluded that EGFR inhibitors can be beneficial in treatment of neurodegenerative diseases and spinal cord injuries. They carry their therapeutic potentials through induction of autophagy and attenuation of reactive astrocytes.


Assuntos
Lesões Encefálicas/metabolismo , Sistema Nervoso Central/crescimento & desenvolvimento , Doenças Neurodegenerativas/metabolismo , Traumatismos da Medula Espinal/metabolismo , Adulto , Animais , Barreira Hematoencefálica/efeitos dos fármacos , Lesões Encefálicas/tratamento farmacológico , Sistema Nervoso Central/metabolismo , Criança , Reposicionamento de Medicamentos , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Terapia de Alvo Molecular , Doenças Neurodegenerativas/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Traumatismos da Medula Espinal/tratamento farmacológico , Regulação para Cima/efeitos dos fármacos
17.
Croat Med J ; 61(2): 159-166, 2020 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-32378382

RESUMO

Health can be defined as a harmony, or homeostasis, of the activities of thousands of different proteins, whereas aging and diseases result from their disharmony manifested at the levels of cells and tissues. Such disharmony is caused primarily by dysfunction and toxicity of misfolded proteins damaged by oxidation. This is an overview of key data that inspired new concepts allowing interpretation and integration of the scientific literature on aging and age-related diseases. These concepts suggest strategies for prevention and attenuation of age-related degenerative and malignant diseases mimicking the life of super-centenarians.


Assuntos
Envelhecimento/fisiologia , Neoplasias , Doenças Neurodegenerativas , Proteínas , Idoso , Dano ao DNA , Humanos , Neoplasias/etiologia , Neoplasias/metabolismo , Neoplasias/fisiopatologia , Doenças Neurodegenerativas/etiologia , Doenças Neurodegenerativas/metabolismo , Doenças Neurodegenerativas/fisiopatologia , Oxirredução , Redobramento de Proteína , Proteínas/química , Proteínas/metabolismo , Proteólise
18.
Adv Exp Med Biol ; 1195: 149, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32468469

RESUMO

Alzheimer's disease and other neurodegenerative diseases have long preclinical phases with active and progressively irreversible pathology. Therefore, biomarkers are essential for identifying patients early in the course of these diseases, when they may benefit the most from disease-modifying interventions. A limitation of biomarkers measured in the soluble phase of blood is their tenuous link to brain pathology. A new approach to biomarker discovery that addresses this limitation is deriving extracellular vesicles (EVs) enriched for neuronal and astrocytic origin from peripheral blood. EVs are membranous particles (subdivided into smaller exosomes and larger microvesicles) that are shed by all cells and found in all biofluids. Neuronal and astrocytic EVs have been implicated in the pathogenesis of several neurodegenerative diseases. Given their origin, neuronal and astrocytic enriched EVs harvested from blood can be used to interrogate brain pathologic processes previously inaccessible in vivo. In a long series of case control studies based on these EV subpopulations, we have identified candidate protein biomarkers for Alzheimer's disease and other neurodegenerative diseases. In GeNeDis 2018, an update of these studies and results from a validation study of these biomarkers in preclinical Alzheimer's disease will be presented. In addition, we will present results from studies demonstrating EV biomarker responses to experimental interventions. EV-based biomarkers are a valuable new tool that will enable researchers to test hypotheses in proof of concept studies with carefully selected participants at the preclinical phase, spearheading therapeutic discovery in neurodegenerative disease.


Assuntos
Biomarcadores/análise , Ensaios Clínicos como Assunto/métodos , Exossomos/química , Doenças Neurodegenerativas/diagnóstico , Doenças Neurodegenerativas/terapia , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Doença de Alzheimer/terapia , Humanos , Doenças Neurodegenerativas/metabolismo , Doenças Neurodegenerativas/patologia , Resultado do Tratamento
19.
Adv Exp Med Biol ; 1195: 237-247, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32468482

RESUMO

MicroRNAs (miRNAs) are small non-coding RNA molecules of about 20-22 nucleotides. After their posttranscriptional maturation, miRNAs are loaded into the ribonucleoprotein complex RISC and modulate gene expression by binding to the 3' untranslated region of their target mRNAs through base-pairing, which in turn triggers mRNA degradation or translational inhibition. There is mounting evidence that miRNAs regulate various biological processes, including cell proliferation, differentiation, and apoptosis. Several studies have shown that miRNAs play an important role in neurogenesis and brain development.This review discusses recent progress on understanding the implication of precisely regulated miRNA expression in normal brain development and function. In addition, it reports known cases of dysregulation of miRNA expression and function implicated in the pathogenesis of neurodevelopmental disorders, craniofacial dysmorphic syndromes, neurodegenerative diseases, and psychiatric disorders. Current knowledge regarding the role of miRNAs in the brain in conjunction with the complex interplay between genetic and epigenetic factors are discussed.


Assuntos
Encéfalo/crescimento & desenvolvimento , Encéfalo/fisiologia , MicroRNAs/metabolismo , Regiões 3' não Traduzidas/genética , Anormalidades Craniofaciais/genética , Anormalidades Craniofaciais/metabolismo , Humanos , Transtornos Mentais/genética , Transtornos Mentais/metabolismo , MicroRNAs/genética , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/metabolismo , Neurogênese/genética
20.
Proc Natl Acad Sci U S A ; 117(19): 10565-10574, 2020 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-32345721

RESUMO

Numerous mutations that impair retrograde membrane trafficking between endosomes and the Golgi apparatus lead to neurodegenerative diseases. For example, mutations in the endosomal retromer complex are implicated in Alzheimer's and Parkinson's diseases, and mutations of the Golgi-associated retrograde protein (GARP) complex cause progressive cerebello-cerebral atrophy type 2 (PCCA2). However, how these mutations cause neurodegeneration is unknown. GARP mutations in yeast, including one causing PCCA2, result in sphingolipid abnormalities and impaired cell growth that are corrected by treatment with myriocin, a sphingolipid synthesis inhibitor, suggesting that alterations in sphingolipid metabolism contribute to cell dysfunction and death. Here we tested this hypothesis in wobbler mice, a murine model with a homozygous partial loss-of-function mutation in Vps54 (GARP protein) that causes motor neuron disease. Cytotoxic sphingoid long-chain bases accumulated in embryonic fibroblasts and spinal cords from wobbler mice. Remarkably, chronic treatment of wobbler mice with myriocin markedly improved their wellness scores, grip strength, neuropathology, and survival. Proteomic analyses of wobbler fibroblasts revealed extensive missorting of lysosomal proteins, including sphingolipid catabolism enzymes, to the Golgi compartment, which may contribute to the sphingolipid abnormalities. Our findings establish that altered sphingolipid metabolism due to GARP mutations contributes to neurodegeneration and suggest that inhibiting sphingolipid synthesis might provide a useful strategy for treating these disorders.


Assuntos
Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Esfingolipídeos/metabolismo , Animais , Modelos Animais de Doenças , Endossomos/metabolismo , Ácidos Graxos Monoinsaturados/farmacologia , Feminino , Fibroblastos/metabolismo , Complexo de Golgi/metabolismo , Masculino , Camundongos , Camundongos Mutantes Neurológicos , Doença dos Neurônios Motores/genética , Doença dos Neurônios Motores/metabolismo , Doença dos Neurônios Motores/patologia , Neurônios Motores/metabolismo , Células-Tronco Embrionárias Murinas , Mutação , Malformações do Sistema Nervoso/metabolismo , Doenças Neurodegenerativas/metabolismo , Doenças Neurodegenerativas/fisiopatologia , Transporte Proteico , Proteômica , Proteínas de Transporte Vesicular/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA