Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 61
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Int J Mol Sci ; 25(11)2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38892355

RESUMO

Parkinson's disease is a progressive neurodegenerative disorder, predominantly of the motor system. Although some genetic components and cellular mechanisms of Parkinson's have been identified, much is still unknown. In recent years, emerging evidence has indicated that non-DNA-sequence variation (in particular epigenetic mechanisms) is likely to play a crucial role in the development and progression of the disease. Here, we present an up-to-date overview of epigenetic processes including DNA methylation, DNA hydroxymethylation, histone modifications and non-coding RNAs implicated in the brain of those with Parkinson's disease. We will also discuss the limitations of current epigenetic research in Parkinson's disease, the advantages of simultaneously studying genetics and epigenetics, and putative novel epigenetic therapies.


Assuntos
Encéfalo , Metilação de DNA , Epigênese Genética , Doença de Parkinson , Doença de Parkinson/genética , Doença de Parkinson/metabolismo , Doença de Parkinson/patologia , Humanos , Encéfalo/metabolismo , Encéfalo/patologia , RNA não Traduzido/genética , Animais , Código das Histonas/genética , Histonas/metabolismo , Histonas/genética
2.
Int J Mol Sci ; 24(3)2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36769009

RESUMO

Parkinson's disease (PD) is a common movement disorder, estimated to affect 4% of individuals by the age of 80. Mutations in the glucocerebrosidase 1 (GBA1) gene represent the most common genetic risk factor for PD, with at least 7-10% of non-Ashkenazi PD individuals carrying a GBA1 mutation (PD-GBA1). Although similar to idiopathic PD, the clinical presentation of PD-GBA1 includes a slightly younger age of onset, a higher incidence of neuropsychiatric symptoms, and a tendency to earlier, more prevalent and more significant cognitive impairment. The pathophysiological mechanisms underlying PD-GBA1 are incompletely understood, but, as in idiopathic PD, α-synuclein accumulation is thought to play a key role. It has been hypothesized that this overexpression of α-synuclein is caused by epigenetic modifications. In this paper, we analyze DNA methylation levels at 17 CpG sites located within intron 1 and the promoter of the α-synuclein (SNCA) gene in three different brain regions (frontal cortex, putamen and substantia nigra) in idiopathic PD, PD-GBA1 and elderly non-PD controls. In all three brain regions we find a tendency towards a decrease in DNA methylation within an eight CpG region of intron 1 in both idiopathic PD and PD-GBA1. The trend towards a reduction in DNA methylation was more pronounced in PD-GBA1, with a significant decrease in the frontal cortex. This suggests that PD-GBA1 and idiopathic PD have distinct epigenetic profiles, and highlights the importance of separating idiopathic PD and PD-GBA1 cases. This work also provides initial evidence that different genetic subtypes might exist within PD, each characterized by its own pathological mechanism. This may have important implications for how PD is diagnosed and treated.


Assuntos
Glucosilceramidase , Doença de Parkinson , Humanos , Idoso , Glucosilceramidase/metabolismo , alfa-Sinucleína/metabolismo , Doença de Parkinson/genética , Doença de Parkinson/tratamento farmacológico , Metilação de DNA , Íntrons/genética , Mutação , Lobo Frontal/metabolismo
3.
Glob Chang Biol ; 28(21): 6293-6317, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36047436

RESUMO

A globally relevant and standardized taxonomy and framework for consistently describing land cover change based on evidence is presented, which makes use of structured land cover taxonomies and is underpinned by the Driver-Pressure-State-Impact-Response (DPSIR) framework. The Global Change Taxonomy currently lists 246 classes based on the notation 'impact (pressure)', with this encompassing the consequence of observed change and associated reason(s), and uses scale-independent terms that factor in time. Evidence for different impacts is gathered through temporal comparison (e.g., days, decades apart) of land cover classes constructed and described from Environmental Descriptors (EDs; state indicators) with pre-defined measurement units (e.g., m, %) or categories (e.g., species type). Evidence for pressures, whether abiotic, biotic or human-influenced, is similarly accumulated, but EDs often differ from those used to determine impacts. Each impact and pressure term is defined separately, allowing flexible combination into 'impact (pressure)' categories, and all are listed in an openly accessible glossary to ensure consistent use and common understanding. The taxonomy and framework are globally relevant and can reference EDs quantified on the ground, retrieved/classified remotely (from ground-based, airborne or spaceborne sensors) or predicted through modelling. By providing capacity to more consistently describe change processes-including land degradation, desertification and ecosystem restoration-the overall framework addresses a wide and diverse range of local to international needs including those relevant to policy, socioeconomics and land management. Actions in response to impacts and pressures and monitoring towards targets are also supported to assist future planning, including impact mitigation actions.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , Monitoramento Ambiental , Humanos
4.
JAMA ; 323(24): 2503-2511, 2020 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-32573669

RESUMO

Importance: Widespread adoption of rapid genomic testing in pediatric critical care requires robust clinical and laboratory pathways that provide equitable and consistent service across health care systems. Objective: To prospectively evaluate the performance of a multicenter network for ultra-rapid genomic diagnosis in a public health care system. Design, Setting, and Participants: Descriptive feasibility study of critically ill pediatric patients with suspected monogenic conditions treated at 12 Australian hospitals between March 2018 and February 2019, with data collected to May 2019. A formal implementation strategy emphasizing communication and feedback, standardized processes, coordination, distributed leadership, and collective learning was used to facilitate adoption. Exposures: Ultra-rapid exome sequencing. Main Outcomes and Measures: The primary outcome was time from sample receipt to ultra-rapid exome sequencing report. The secondary outcomes were the molecular diagnostic yield, the change in clinical management after the ultra-rapid exome sequencing report, the time from hospital admission to the laboratory report, and the proportion of laboratory reports returned prior to death or hospital discharge. Results: The study population included 108 patients with a median age of 28 days (range, 0 days to 17 years); 34% were female; and 57% were from neonatal intensive care units, 33% were from pediatric intensive care units, and 9% were from other hospital wards. The mean time from sample receipt to ultra-rapid exome sequencing report was 3.3 days (95% CI, 3.2-3.5 days) and the median time was 3 days (range, 2-7 days). The mean time from hospital admission to ultra-rapid exome sequencing report was 17.5 days (95% CI, 14.6-21.1 days) and 93 reports (86%) were issued prior to death or hospital discharge. A molecular diagnosis was established in 55 patients (51%). Eleven diagnoses (20%) resulted from using the following approaches to augment standard exome sequencing analysis: mitochondrial genome sequencing analysis, exome sequencing-based copy number analysis, use of international databases to identify novel gene-disease associations, and additional phenotyping and RNA analysis. In 42 of 55 patients (76%) with a molecular diagnosis and 6 of 53 patients (11%) without a molecular diagnosis, the ultra-rapid exome sequencing result was considered as having influenced clinical management. Targeted treatments were initiated in 12 patients (11%), treatment was redirected toward palliative care in 14 patients (13%), and surveillance for specific complications was initiated in 19 patients (18%). Conclusions and Relevance: This study suggests feasibility of ultra-rapid genomic testing in critically ill pediatric patients with suspected monogenic conditions in the Australian public health care system. However, further research is needed to understand the clinical value of such testing, and the generalizability of the findings to other health care settings.


Assuntos
Estado Terminal , Sequenciamento do Exoma/métodos , Doenças Genéticas Inatas/genética , Testes Genéticos/métodos , Austrália , Criança , Pré-Escolar , Estudos de Viabilidade , Feminino , Doenças Genéticas Inatas/diagnóstico , Humanos , Lactente , Recém-Nascido , Masculino , Programas Nacionais de Saúde , Estudos Prospectivos , Fatores de Tempo
5.
Lancet ; 391(10140): 2619-2630, 2018 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-29910042

RESUMO

BACKGROUND: B cells produce alloantibodies and activate alloreactive T cells, negatively affecting kidney transplant survival. By contrast, regulatory B cells are associated with transplant tolerance. Immunotherapies are needed that inhibit B-cell effector function, including antibody secretion, while sparing regulators and minimising infection risk. B lymphocyte stimulator (BLyS) is a cytokine that promotes B-cell activation and has not previously been targeted in kidney transplant recipients. We aimed to determine the safety and activity of an anti-BLyS antibody, belimumab, in addition to standard-of-care immunosuppression in adult kidney transplant recipients. We used an experimental medicine study design with multiple secondary and exploratory endpoints to gain further insight into the effect of belimumab on the generation of de-novo IgG and on the regulatory B-cell compartment. METHODS: We undertook a double-blind, randomised, placebo-controlled phase 2 trial of belimumab, in addition to standard-of-care immunosuppression (basiliximab, mycophenolate mofetil, tacrolimus, and prednisolone) at two centres, Addenbrooke's Hospital, Cambridge, UK, and Guy's and St Thomas' Hospital, London, UK. Participants were eligible if they were aged 18-75 years and receiving a kidney transplant and were planned to receive standard-of-care immunosuppression. Participants were randomly assigned (1:1) to receive either intravenous belimumab 10 mg per kg bodyweight or placebo, given at day 0, 14, and 28, and then every 4 weeks for a total of seven infusions. The co-primary endpoints were safety and change in the concentration of naive B cells from baseline to week 24, both of which were analysed in all patients who received a transplant and at least one dose of drug or placebo (the modified intention-to-treat [mITT] population). This trial has been completed and is registered with ClinicalTrials.gov, NCT01536379, and EudraCT, 2011-006215-56. FINDINGS: Between Sept 13, 2013, and Feb 8, 2015, of 303 patients assessed for eligibility, 28 kidney transplant recipients were randomly assigned to receive belimumab (n=14) or placebo (n=14). 25 patients (12 [86%] patients assigned to the belimumab group and 13 [93%] patients assigned to the placebo group) received a transplant and were included in the mITT population. We observed similar proportions of adverse events in the belimumab and placebo groups, including serious infections (one [8%] of 12 in the belimumab group and five [38%] of 13 in the placebo group during the 6-month on-treatment phase; and none in the belimumab group and two [15%] in the placebo group during the 6-month follow-up). In the on-treatment phase, one patient in the placebo group died because of fatal myocardial infarction and acute cardiac failure. The co-primary endpoint of a reduction in naive B cells from baseline to week 24 was not met. Treatment with belimumab did not significantly reduce the number of naive B cells from baseline to week 24 (adjusted mean difference between the belimumab and placebo treatment groups -34·4 cells per µL, 95% CI -109·5 to 40·7). INTERPRETATION: Belimumab might be a useful adjunct to standard-of-care immunosuppression in renal transplantation, with no major increased risk of infection and potential beneficial effects on humoral alloimmunity. FUNDING: GlaxoSmithKline.


Assuntos
Anticorpos Monoclonais Humanizados/administração & dosagem , Sobrevivência de Enxerto/efeitos dos fármacos , Terapia de Imunossupressão/métodos , Imunossupressores/administração & dosagem , Transplante de Rim/métodos , Administração Intravenosa , Adulto , Idoso , Método Duplo-Cego , Feminino , Humanos , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade
6.
J Biol Chem ; 292(32): 13345-13360, 2017 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-28637873

RESUMO

Spontaneous activation enables the complement system to respond very rapidly to diverse threats. This activation is efficiently suppressed by complement factor H (CFH) on self-surfaces but not on foreign surfaces. The surface selectivity of CFH, a soluble protein containing 20 complement-control protein modules (CCPs 1-20), may be compromised by disease-linked mutations. However, which of the several functions of CFH drives this self-surface selectivity remains unknown. To address this, we expressed human CFH mutants in Pichia pastoris We found that recombinant I62-CFH (protective against age-related macular degeneration) and V62-CFH functioned equivalently, matching or outperforming plasma-derived CFH, whereas R53H-CFH, linked to atypical hemolytic uremic syndrome (aHUS), was defective in C3bBb decay-accelerating activity (DAA) and factor I cofactor activity (CA). The aHUS-linked CCP 19 mutant D1119G-CFH had virtually no CA on (self-like) sheep erythrocytes (ES) but retained DAA. The aHUS-linked CCP 20 mutant S1191L/V1197A-CFH (LA-CFH) had dramatically reduced CA on ES but was less compromised in DAA. D1119G-CFH and LA-CFH both performed poorly at preventing complement-mediated hemolysis of ES PspCN, a CFH-binding Streptococcus pneumoniae protein domain, binds CFH tightly and increases accessibility of CCPs 19 and 20. PspCN did not improve the DAA of any CFH variant on ES Conversely, PspCN boosted the CA, on ES, of I62-CFH, R53H-CFH, and LA-CFH and also enhanced hemolysis protection by I62-CFH and LA-CFH. We conclude that CCPs 19 and 20 are critical for efficient CA on self-surfaces but less important for DAA. Exposing CCPs 19 and 20 with PspCN and thus enhancing CA on self-surfaces may reverse deficiencies of some CFH variants.


Assuntos
Síndrome Hemolítico-Urêmica Atípica/genética , Ativação do Complemento , Degeneração Macular/genética , Mutação , Substituição de Aminoácidos , Animais , Síndrome Hemolítico-Urêmica Atípica/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Sítios de Ligação , C3 Convertase da Via Alternativa do Complemento/química , C3 Convertase da Via Alternativa do Complemento/genética , C3 Convertase da Via Alternativa do Complemento/metabolismo , Complemento C3d/química , Complemento C3d/genética , Complemento C3d/metabolismo , Fator H do Complemento/química , Fator H do Complemento/genética , Fator H do Complemento/metabolismo , Fator I do Complemento/química , Fator I do Complemento/genética , Fator I do Complemento/metabolismo , Eritrócitos/química , Hemólise , Humanos , Proteínas Imobilizadas/química , Proteínas Imobilizadas/genética , Proteínas Imobilizadas/metabolismo , Degeneração Macular/metabolismo , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/metabolismo , Domínios e Motivos de Interação entre Proteínas , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/metabolismo , Carneiro Doméstico , Solubilidade , Streptococcus pneumoniae/metabolismo , Propriedades de Superfície
7.
Hum Mol Genet ; 25(16): 3432-3445, 2016 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-27378698

RESUMO

Glucocerebrosidase (GBA1) gene mutations increase the risk of Parkinson disease (PD). While the cellular mechanisms associating GBA1 mutations and PD are unknown, loss of the glucocerebrosidase enzyme (GCase) activity, inhibition of autophagy and increased α-synuclein levels have been implicated. Here we show that autophagy lysosomal reformation (ALR) is compromised in cells lacking functional GCase. ALR is a cellular process controlled by mTOR which regenerates functional lysosomes from autolysosomes formed during macroautophagy. A decrease in phopho-S6K levels, a marker of mTOR activity, was observed in models of GCase deficiency, including primary mouse neurons and the PD patient derived fibroblasts with GBA1 mutations, suggesting that ALR is compromised. Importantly Rab7, a GTPase crucial for endosome-lysosome trafficking and ALR, accumulated in GCase deficient cells, supporting the notion that lysosomal recycling is impaired. Recombinant GCase treatment reversed ALR inhibition and lysosomal dysfunction. Moreover, ALR dysfunction was accompanied by impairment of macroautophagy and chaperone-mediated autophagy, increased levels of total and phosphorylated (S129) monomeric α-synuclein, evidence of amyloid oligomers and increased α-synuclein release. Concurrently, we found increased cholesterol and altered glucosylceramide homeostasis which could compromise ALR. We propose that GCase deficiency in PD inhibits lysosomal recycling. Consequently neurons are unable to maintain the pool of mature and functional lysosomes required for the autophagic clearance of α-synuclein, leading to the accumulation and spread of pathogenic α-synuclein species in the brain. Since GCase deficiency and lysosomal dysfunction occur with ageing and sporadic PD pathology, the decrease in lysosomal reformation may be a common feature in PD.


Assuntos
Glucosilceramidase/genética , Neurônios/metabolismo , Doença de Parkinson/genética , alfa-Sinucleína/genética , Proteínas rab de Ligação ao GTP/genética , Animais , Autofagia/genética , Encéfalo/metabolismo , Encéfalo/patologia , Fibroblastos/metabolismo , Fibroblastos/patologia , Doença de Gaucher/genética , Doença de Gaucher/patologia , Glucosilceramidase/metabolismo , Humanos , Lisossomos/genética , Lisossomos/metabolismo , Camundongos , Mutação , Neurônios/patologia , Doença de Parkinson/patologia , proteínas de unión al GTP Rab7
8.
Brain ; 140(10): 2706-2721, 2017 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-28969384

RESUMO

Mutations in glucocerebrosidase 1 (GBA1) represent the most prevalent risk factor for Parkinson's disease. The molecular mechanisms underlying the link between GBA1 mutations and Parkinson's disease are incompletely understood. We analysed two aged (24-month-old) Gba1 mouse models, one carrying a knock-out mutation and the other a L444P knock-in mutation. A significant reduction of glucocerebrosidase activity was associated with increased total alpha-synuclein accumulation in both these models. Gba1 mutations alone did not alter the number of nigral dopaminergic neurons nor striatal dopamine levels. We then investigated the effect of overexpression of human alpha-synuclein in the substantia nigra of aged (18 to 21-month-old) L444P Gba1 mice. Following intraparenchymal injections of human alpha-synuclein carrying viral vectors, pathological accumulation of phosphorylated alpha-synuclein occurred within the transduced neurons. Stereological counts of nigral dopaminergic neurons revealed a significantly greater cell loss in Gba1-mutant than wild-type mice. These results indicate that Gba1 deficiency enhances neuronal vulnerability to neurodegenerative processes triggered by increased alpha-synuclein expression.


Assuntos
Dopamina/metabolismo , Glucosilceramidase/genética , Mutação/genética , Neurônios/patologia , Substância Negra/patologia , alfa-Sinucleína/metabolismo , Fatores Etários , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Glucosilceramidase/deficiência , Humanos , Leucina/genética , Camundongos , Camundongos Transgênicos , Neurônios/metabolismo , Prolina/genética , Desempenho Psicomotor/fisiologia , Olfato/genética , Substância Negra/metabolismo , Transdução Genética , Tirosina 3-Mono-Oxigenase/metabolismo , beta-N-Acetil-Hexosaminidases/metabolismo
9.
Ann Neurol ; 80(5): 766-775, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27859541

RESUMO

OBJECTIVE: Gaucher disease is caused by mutations in the glucocerebrosidase 1 gene that result in deficiency of the lysosomal enzyme glucocerebrosidase. Both homozygous and heterozygous glucocerebrosidase 1 mutations confer an increased risk for developing Parkinson disease. Current estimates indicate that 10 to 25% of Parkinson patients carry glucocerebrosidase 1 mutations. Ambroxol is a small molecule chaperone that has been shown to increase glucocerebrosidase activity in vitro. This study investigated the effect of ambroxol treatment on glucocerebrosidase activity and on α-synuclein and phosphorylated α-synuclein protein levels in mice. METHODS: Mice were treated with ambroxol for 12 days. After the treatment, glucocerebrosidase activity was measured in the mouse brain lysates. The brain lysates were also analyzed for α-synuclein and phosphorylated α-synuclein protein levels. RESULTS: Ambroxol treatment resulted in increased brain glucocerebrosidase activity in (1) wild-type mice, (2) transgenic mice expressing the heterozygous L444P mutation in the murine glucocerebrosidase 1 gene, and (3) transgenic mice overexpressing human α-synuclein. Furthermore, in the mice overexpressing human α-synuclein, ambroxol treatment decreased both α-synuclein and phosphorylated α-synuclein protein levels. INTERPRETATION: Our work supports the proposition that ambroxol should be further investigated as a potential novel disease-modifying therapy for treatment of Parkinson disease and neuronopathic Gaucher disease to increase glucocerebrosidase activity and decrease α-synuclein and phosphorylated α-synuclein protein levels. Ann Neurol 2016;80:766-775.


Assuntos
Ambroxol/farmacologia , Encéfalo/efeitos dos fármacos , Expectorantes/farmacologia , Doença de Gaucher/tratamento farmacológico , Glucosilceramidase/efeitos dos fármacos , Doença de Parkinson/tratamento farmacológico , alfa-Sinucleína/efeitos dos fármacos , Ambroxol/administração & dosagem , Animais , Modelos Animais de Doenças , Expectorantes/administração & dosagem , Humanos , Camundongos , Camundongos Transgênicos
10.
Synapse ; 71(7)2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28295625

RESUMO

Mutations in the glucocerebrosidase 1 (GBA1) gene are related to both Parkinson disease (PD) and Gaucher disease (GD). In both cases, the condition is associated with deficiency of glucocerebrosidase (GCase), the enzyme encoded by GBA1. Ambroxol is a small molecule chaperone that has been shown in mice to cross the blood-brain barrier, increase GCase activity and reduce alpha-synuclein protein levels. In this study, we analyze the effect of ambroxol treatment on GCase activity in healthy nonhuman primates. We show that daily administration of ambroxol results in increased brain GCase activity. Our work further indicates that ambroxol should be investigated as a novel therapy for both PD and neuronopathic GD in humans.


Assuntos
Ambroxol/administração & dosagem , Encéfalo/efeitos dos fármacos , Encéfalo/enzimologia , Fármacos do Sistema Nervoso Central/administração & dosagem , Glucosilceramidase/metabolismo , Administração Oral , Animais , Macaca fascicularis , Masculino , Dados Preliminares , Cadeia beta da beta-Hexosaminidase/metabolismo
11.
J Immunol ; 195(10): 4986-98, 2015 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-26459349

RESUMO

In an attempt to evade annihilation by the vertebrate complement system, many microbes capture factor H (FH), the key soluble complement-regulating protein in human plasma. However, FH is normally an active complement suppressor exclusively on self-surfaces and this selective action of FH is pivotal to self versus non-self discrimination by the complement system. We investigated whether the bacterially captured FH becomes functionally enhanced and, if so, how this is achieved at a structural level. We found, using site-directed and truncation mutagenesis, surface plasmon resonance, nuclear magnetic resonance spectroscopy, and cross-linking and mass spectrometry, that the N-terminal domain of Streptococcus pneumoniae protein PspC (PspCN) not only binds FH extraordinarily tightly but also holds it in a previously uncharacterized conformation. Functional enhancement arises from exposure of a C-terminal cryptic second binding site in FH for C3b, the activation-specific fragment of the pivotal complement component, C3. This conformational change of FH doubles its affinity for C3b and increases 5-fold its ability to accelerate decay of the binary enzyme (C3bBb) responsible for converting C3 to C3b in an amplification loop. Despite not sharing critical FH-binding residues, PspCNs from D39 and Tigr4 S. pneumoniae exhibit similar FH-anchoring and enhancing properties. We propose that these bacterial proteins mimic molecular markers of self-surfaces, providing a compelling hypothesis for how FH prevents complement-mediated injury to host tissue while lacking efficacy on virtually all other surfaces. In hemolysis assays with 2-aminoethylisothiouronium bromide-treated erythrocytes that recapitulate paroxysmal nocturnal hemoglobinuria, PspCN enhanced protection of cells by FH, suggesting a new paradigm for therapeutic complement suppression.


Assuntos
Proteínas de Bactérias/química , Complemento C3b/química , Fator H do Complemento/química , Streptococcus pneumoniae/química , Proteínas de Bactérias/imunologia , Complemento C3b/imunologia , Fator H do Complemento/imunologia , Hemoglobinúria Paroxística/imunologia , Humanos , Estrutura Terciária de Proteína , Streptococcus pneumoniae/imunologia
12.
J Neurochem ; 139 Suppl 1: 77-90, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-26860875

RESUMO

Parkinson disease (PD) is the second most common neurodegenerative disorder after Alzheimer disease, whereas Gaucher disease (GD) is the most frequent lysosomal storage disorder caused by homozygous mutations in the glucocerebrosidase (GBA1) gene. Increased risk of developing PD has been observed in both GD patients and carriers. It has been estimated that GBA1 mutations confer a 20- to 30-fold increased risk for the development of PD, and that at least 7-10% of PD patients have a GBA1 mutation. To date, mutations in the GBA1 gene constitute numerically the most important risk factor for PD. The type of PD associated with GBA1 mutations (PD-GBA1) is almost identical to idiopathic PD, except for a slightly younger age of onset and a tendency to more cognitive impairment. Importantly, the pathology of PD-GBA1 is identical to idiopathic PD, with nigral dopamine cell loss, Lewy bodies, and neurites containing alpha-synuclein. The mechanism by which GBA1 mutations increase the risk for PD is still unknown. However, given that clinical manifestation and pathological findings in PD-GBA1 patients are almost identical to those in idiopathic PD individuals, it is likely that, as in idiopathic PD, alpha-synuclein accumulation, mitochondrial dysfunction, autophagic impairment, oxidative and endoplasmic reticulum stress may contribute to the development and progression of PD-GBA1. Here, we review the GBA1 gene, its role in GD, and its link with PD. The impact of glucocerebrosidase 1 (GBA1) mutations on functioning of endoplasmic reticulum (ER), lysosomes, and mitochondria. GBA1 mutations resulting in production of misfolded glucocerebrosidase (GCase) significantly affect the ER functioning. Misfolded GCase trapped in the ER leads to both an increase in the ubiquitin-proteasome system (UPS) and the ER stress. The presence of ER stress triggers the unfolded protein response (UPR) and/or endoplasmic reticulum-associated degradation (ERAD). The prolonged activation of UPR and ERAD subsequently leads to increased apoptosis. The presence of misfolded GCase in the lysosomes together with a reduction in wild-type GCase levels lead to a retardation of alpha-synuclein degradation via chaperone-mediated autophagy (CMA), which subsequently results in alpha-synuclein accumulation and aggregation. Impaired lysosomal functioning also causes a decrease in the clearance of autophagosomes, and so their accumulation. GBA1 mutations perturb normal mitochondria functioning by increasing generation of free radical species (ROS) and decreasing adenosine triphosphate (ATP) production, oxygen consumption, and membrane potential. GBA1 mutations also lead to accumulation of dysfunctional and fragmented mitochondria. This article is part of a special issue on Parkinson disease.


Assuntos
Glucosilceramidase/genética , Glucosilceramidase/metabolismo , Mutação/genética , Doença de Parkinson/enzimologia , Doença de Parkinson/genética , Animais , Autofagia/genética , Doença de Gaucher/diagnóstico , Doença de Gaucher/enzimologia , Doença de Gaucher/genética , Humanos , Lisossomos/enzimologia , Lisossomos/genética , Mitocôndrias/enzimologia , Mitocôndrias/genética , Doença de Parkinson/diagnóstico
13.
Nat Genet ; 39(9): 1068-70, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17660820

RESUMO

Autosomal dominant retinal vasculopathy with cerebral leukodystrophy is a microvascular endotheliopathy with middle-age onset. In nine families, we identified heterozygous C-terminal frameshift mutations in TREX1, which encodes a 3'-5' exonuclease. These truncated proteins retain exonuclease activity but lose normal perinuclear localization. These data have implications for the maintenance of vascular integrity in the degenerative cerebral microangiopathies leading to stroke and dementias.


Assuntos
Encefalopatias/genética , Exodesoxirribonucleases/genética , Mutação , Fosfoproteínas/genética , Doenças Retinianas/genética , Sequência de Aminoácidos , Encefalopatias/enzimologia , Linhagem Celular , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Exodesoxirribonucleases/química , Exodesoxirribonucleases/metabolismo , Genes Dominantes , Predisposição Genética para Doença , Humanos , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Microscopia Confocal , Dados de Sequência Molecular , Fosfoproteínas/química , Fosfoproteínas/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Doenças Retinianas/enzimologia , Homologia de Sequência de Aminoácidos , Transfecção
14.
Oecologia ; 178(1): 297-308, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25502440

RESUMO

Water and nitrogen (N) interact to influence soil N cycling and plant N acquisition. We studied indices of soil N availability and acquisition by woody plant taxa with distinct nutritional specialisations along a north Australian rainfall gradient from monsoonal savanna (1,600-1,300 mm annual rainfall) to semi-arid woodland (600-250 mm). Aridity resulted in increased 'openness' of N cycling, indicated by increasing δ(15)N(soil) and nitrate:ammonium ratios, as plant communities transitioned from N to water limitation. In this context, we tested the hypothesis that δ(15)N(root) xylem sap provides a more direct measure of plant N acquisition than δ(15)N(foliage). We found highly variable offsets between δ(15)N(foliage) and δ(15)N(root) xylem sap, both between taxa at a single site (1.3-3.4 ‰) and within taxa across sites (0.8-3.4 ‰). As a result, δ(15)N(foliage) overlapped between N-fixing Acacia and non-fixing Eucalyptus/Corymbia and could not be used to reliably identify biological N fixation (BNF). However, Acacia δ(15)N(root) xylem sap indicated a decline in BNF with aridity corroborated by absence of root nodules and increasing xylem sap nitrate concentrations and consistent with shifting resource limitation. Acacia dominance at arid sites may be attributed to flexibility in N acquisition rather than BNF capacity. δ(15)N(root) xylem sap showed no evidence of shifting N acquisition in non-mycorrhizal Hakea/Grevillea and indicated only minor shifts in Eucalyptus/Corymbia consistent with enrichment of δ(15)N(soil) and/or decreasing mycorrhizal colonisation with aridity. We propose that δ(15)N(root) xylem sap is a more direct indicator of N source than δ(15)N(foliage), with calibration required before it could be applied to quantify BNF.


Assuntos
Secas , Ecossistema , Ciclo do Nitrogênio , Fixação de Nitrogênio , Nitrogênio/metabolismo , Plantas/metabolismo , Chuva , Acacia/crescimento & desenvolvimento , Acacia/metabolismo , Austrália , Eucalyptus/crescimento & desenvolvimento , Eucalyptus/metabolismo , Florestas , Pradaria , Micorrizas , Isótopos de Nitrogênio/metabolismo , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Solo , Árvores , Água , Madeira/metabolismo , Xilema/metabolismo
15.
J Am Soc Nephrol ; 25(11): 2425-33, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24722444

RESUMO

Complement C3 activation is a characteristic finding in membranoproliferative GN (MPGN). This activation can be caused by immune complex deposition or an acquired or inherited defect in complement regulation. Deficiency of complement factor H has long been associated with MPGN. More recently, heterozygous genetic variants have been reported in sporadic cases of MPGN, although their functional significance has not been assessed. We describe a family with MPGN and acquired partial lipodystrophy. Although C3 nephritic factor was shown in family members with acquired partial lipodystrophy, it did not segregate with the renal phenotype. Genetic analysis revealed a novel heterozygous mutation in complement factor H (R83S) in addition to known risk polymorphisms carried by individuals with MPGN. Patients with MPGN had normal levels of factor H, and structural analysis of the mutant revealed only subtle alterations. However, functional analysis revealed profoundly reduced C3b binding, cofactor activity, and decay accelerating activity leading to loss of regulation of the alternative pathway. In summary, this family showed a confluence of common and rare functionally significant genetic risk factors causing disease. Data from our analysis of these factors highlight the role of the alternative pathway of complement in MPGN.


Assuntos
Fator H do Complemento/deficiência , Fator H do Complemento/genética , Via Alternativa do Complemento/genética , Eritrócitos/imunologia , Glomerulonefrite Membranoproliferativa/genética , Glomerulonefrite Membranoproliferativa/imunologia , Nefropatias/genética , Animais , Fator H do Complemento/química , Fator H do Complemento/imunologia , Via Alternativa do Complemento/imunologia , Cristalografia por Raios X , Eritrócitos/citologia , Saúde da Família , Feminino , Haplótipos , Doenças da Deficiência Hereditária de Complemento , Heterozigoto , Humanos , Nefropatias/imunologia , Masculino , Linhagem , Polimorfismo Genético , Estrutura Terciária de Proteína , Ovinos , Relação Estrutura-Atividade
16.
J Am Geriatr Soc ; 2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38551247

RESUMO

BACKGROUND: Kaiser Permanente Southern California began offering a 4-week supplemental benefit of home-delivered meals to Medicare Advantage members after discharge from a hospitalization for heart failure and other medical conditions in 2021. The purpose of this study is to explore the associations between socioeconomic disadvantage and food insecurity with patient uptake of and satisfaction with the meals. METHODS: Data for this cross-sectional study were drawn from survey and electronic medical record data for members referred for the meals benefit (n = 6169) and linked to a hospitalization encounter (n = 2254) between January and December 2021. Uptake was assessed using vendor records; measures of socioeconomic status included the neighborhood deprivation index (NDI) and prior receipt of medical financial assistance (MFA) from the health system. Patients were invited to complete an email or phone survey about their satisfaction with the meals and food insecurity. Multivariable log-binomial regression models were used to examine the association between socioeconomic disadvantage and food insecurity with meals uptake and satisfaction. RESULTS: Sixty-two percent of patients referred for the benefit accepted the meals (mean age: 79 ± 9, 59% people of color). While there was no significant relationship between NDI and meals uptake (RR: 0.99, 95% CI: 0.92-1.07, p = 0.77), patients who received prior MFA were more likely to accept the meals (RR: 1.09, 95% CI: 1.02-1.16, p < 0.01). Sixty-nine percent of patients who completed the survey (23% response rate) reported that meals were very or extremely helpful. Patients with food insecurity (29% of survey respondents) were more likely to report that the meals were helpful for their recovery compared to food secure patients (RR: 1.21, 95% CI: 1.09-1.35, p < 0.01). CONCLUSIONS: The home-delivered meals appeared to be particularly utilized by and helpful to patients with greater financial strain and/or food insecurity, suggesting that supplemental benefits could be more targeted toward addressing unmet needs of vulnerable adults.

17.
Cells ; 13(8)2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38667288

RESUMO

As the treatment landscape for prostate cancer gradually evolves, the frequency of treatment-induced neuroendocrine prostate cancer (NEPC) and double-negative prostate cancer (DNPC) that is deficient for androgen receptor (AR) and neuroendocrine (NE) markers has increased. These prostate cancer subtypes are typically refractory to AR-directed therapies and exhibit poor clinical outcomes. Only a small range of NEPC/DNPC models exist, limiting our molecular understanding of this disease and hindering our ability to perform preclinical trials exploring novel therapies to treat NEPC/DNPC that are urgently needed in the clinic. Here, we report the development of the CU-PC01 PDX model that represents AR-negative mCRPC with PTEN/RB/PSMA loss and CTNN1B/TP53/BRCA2 genetic variants. The CU-PC01 model lacks classic NE markers, with only focal and/or weak expression of chromogranin A, INSM1 and CD56. Collectively, these findings are most consistent with a DNPC phenotype. Ex vivo and in vivo preclinical studies revealed that CU-PC01 PDX tumours are resistant to mCRPC standard-of-care treatments enzalutamide and docetaxel, mirroring the donor patient's treatment response. Furthermore, short-term CU-PC01 tumour explant cultures indicate this model is initially sensitive to PARP inhibition with olaparib. Thus, the CU-PC01 PDX model provides a valuable opportunity to study AR-negative mCRPC biology and to discover new treatment avenues for this hard-to-treat disease.


Assuntos
Piperazinas , Neoplasias de Próstata Resistentes à Castração , Receptores Androgênicos , Masculino , Humanos , Neoplasias de Próstata Resistentes à Castração/patologia , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/metabolismo , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Animais , Receptores Androgênicos/metabolismo , Receptores Androgênicos/genética , Camundongos , Ensaios Antitumorais Modelo de Xenoenxerto , Feniltioidantoína/farmacologia , Feniltioidantoína/análogos & derivados , Feniltioidantoína/uso terapêutico , Metástase Neoplásica , Nitrilas/farmacologia , Modelos Animais de Doenças , Benzamidas/farmacologia , Ftalazinas/farmacologia , Ftalazinas/uso terapêutico
18.
Am J Hum Biol ; 25(4): 457-64, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23754612

RESUMO

OBJECTIVES: Studies testing whether systemic inflammation might lie on the causal pathway between aberrant fetal and post-natal growth patterns and later cardiovascular disease have been inconclusive, possibly due to the use of single markers of unknown predictive value. We used repeated measures of a comprehensive set of inflammatory markers to investigate the relationship between early life measures and systemic inflammation in an African population. METHODS: Individuals born in three rural villages in The Gambia, and for whom early life measurements were recorded, were traced (n = 320). Fasting levels of eight inflammatory markers (C-reactive protein, serum amyloid A, orosomucoid, fibrinogen, α 1-antichymotrypsin, sialic acid, interleukin-6 and neopterin) were measured, and potential confounding factors recorded. The association between early life measurements and systemic inflammation was assessed using regression analysis. RESULTS: Levels of most markers were unrelated to early growth patterns. In analyses adjusted for age and sex, more rapid growth between birth and 3 months of age was associated with higher levels of fibrinogen, orosomucoid, and sialic acid. These relationships persisted after further adjustment for body mass index but after full adjustment only the association with fibrinogen remained. CONCLUSIONS: This study provides little evidence that size at birth or growth in early infancy determine levels of inflammatory markers in young Gambian adults.


Assuntos
Peso ao Nascer/fisiologia , Desenvolvimento Infantil/fisiologia , Mediadores da Inflamação/metabolismo , Estações do Ano , Adolescente , Adulto , Biomarcadores , Pesos e Medidas Corporais , Doença Crônica , Feminino , Gâmbia/epidemiologia , Comportamentos Relacionados com a Saúde , Humanos , Recém-Nascido , Estilo de Vida , Masculino , População Rural , Adulto Jovem
19.
Kidney Int Rep ; 8(10): 2056-2067, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37850014

RESUMO

Introduction: Despite recognized geographic and sex-based differences in hemoglobin in the general population, these factors are typically ignored in patients with chronic kidney disease (CKD) in whom a single therapeutic range for hemoglobin is recommended. We sought to compare the distribution of hemoglobin across international nondialysis CKD populations and evaluate predictors of hemoglobin. Methods: In this cross-sectional study, hemoglobin distribution was evaluated in each cohort overall and stratified by sex and estimated glomerular filtration rate (eGFR). Relationships between candidate predictors and hemoglobin were assessed from linear regression models in each cohort. Estimates were subsequently pooled in a random effects model. Results: A total of 58,613 participants from 21 adult cohorts (median eGFR range of 17-49 ml/min) and 3 pediatric cohorts (median eGFR range of 26-45 ml/min) were included with broad geographic representation. Hemoglobin values varied substantially among the cohorts, overall and within eGFR categories, with particularly low mean hemoglobin observed in women from Asian and African cohorts. Across the eGFR range, women had a lower hemoglobin compared to men, even at an eGFR of 15 ml/min (mean difference 5.3 g/l, 95% confidence interval [CI] 3.7-6.9). Lower eGFR, female sex, older age, lower body mass index, and diabetic kidney disease were all independent predictors of a lower hemoglobin value; however, this only explained a minority of variance (R2 7%-44% across cohorts). Conclusion: There are substantial regional differences in hemoglobin distribution among individuals with CKD, and the majority of variance is unexplained by demographics, eGFR, or comorbidities. These findings call for a renewed interest in improving our understanding of hemoglobin determinants in specific CKD populations.

20.
Cancers (Basel) ; 14(2)2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-35053592

RESUMO

Interleukin (IL)-6 family cytokines, such as IL-6 and IL-11, are defined by the shared use of the gp130 receptor for the downstream activation of STAT3 signaling and the activation of genes which contribute to the "hallmarks of cancer", including proliferation, survival, invasion and metastasis. Increased expression of these cytokines, or the ligand-specific receptors IL-6R and IL-11RA, in breast tumors positively correlate to disease progression and poorer patient outcome. In this review, we examine evidence from pre-clinical studies that correlate enhanced IL-6 and IL-11 mediated gp130/STAT3 signaling to the progression of breast cancer. Key processes by which the IL-6 family cytokines contribute to the heterogeneous nature of breast cancer, immune evasion and metastatic potential, are discussed. We examine the latest research into the therapeutic targeting of IL-6 family cytokines that inhibit STAT3 transcriptional activity as a potential breast cancer treatment, including current clinical trials. The importance of the IL-6 family of cytokines in cellular processes that promote the development and progression of breast cancer warrants further understanding of the molecular basis for its actions to help guide the development of future therapeutic targets.

SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa