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Alzheimer's disease is a complex neurodegenerative disorder leading to a decline in cognitive function and mental health. Recent research has positioned the gut microbiota as an important susceptibility factor in Alzheimer's disease by showing specific alterations in the gut microbiome composition of Alzheimer's patients and in rodent models. However, it is unknown whether gut microbiota alterations are causal in the manifestation of Alzheimer's symptoms. To understand the involvement of Alzheimer's patient gut microbiota in host physiology and behaviour, we transplanted faecal microbiota from Alzheimer's patients and age-matched healthy controls into microbiota-depleted young adult rats. We found impairments in behaviours reliant on adult hippocampal neurogenesis, an essential process for certain memory functions and mood, resulting from Alzheimer's patient transplants. Notably, the severity of impairments correlated with clinical cognitive scores in donor patients. Discrete changes in the rat caecal and hippocampal metabolome were also evident. As hippocampal neurogenesis cannot be measured in living humans but is modulated by the circulatory systemic environment, we assessed the impact of the Alzheimer's systemic environment on proxy neurogenesis readouts. Serum from Alzheimer's patients decreased neurogenesis in human cells in vitro and were associated with cognitive scores and key microbial genera. Our findings reveal for the first time, that Alzheimer's symptoms can be transferred to a healthy young organism via the gut microbiota, confirming a causal role of gut microbiota in Alzheimer's disease, and highlight hippocampal neurogenesis as a converging central cellular process regulating systemic circulatory and gut-mediated factors in Alzheimer's.
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Doença de Alzheimer , Microbioma Gastrointestinal , Humanos , Ratos , Animais , Hipocampo , Cognição , Microbioma Gastrointestinal/fisiologia , Neurogênese/fisiologiaRESUMO
Lipoprotein lipase (LPL) is a secreted lipase that clears triglycerides from the blood. Proper LPL folding and exit from the endoplasmic reticulum (ER) require lipase maturation factor 1 (LMF1), an ER-resident transmembrane protein, but the mechanism involved is unknown. We used proteomics to identify LMF1-binding partners necessary for LPL secretion in HEK293 cells and found these to include oxidoreductases and lectin chaperones, suggesting that LMF1 facilitates the formation of LPL's five disulfide bonds. In accordance with this role, we found that LPL aggregates in LMF1-deficient cells due to the formation of incorrect intermolecular disulfide bonds. Cells lacking LMF1 were hypersensitive to depletion of glutathione, but not DTT treatment, suggesting that LMF1 helps reduce the ER Accordingly, we found that loss of LMF1 results in a more oxidized ER Our data show that LMF1 has a broader role than simply folding lipases, and we identified fibronectin and the low-density lipoprotein receptor (LDLR) as novel LMF1 clients that contain multiple, non-sequential disulfide bonds. We conclude that LMF1 is needed for secretion of some ER client proteins that require reduction of non-native disulfides during their folding.
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Retículo Endoplasmático/metabolismo , Homeostase , Proteínas de Membrana/metabolismo , Dobramento de Proteína , Dissulfetos/metabolismo , Retículo Endoplasmático/genética , Fibronectinas/genética , Fibronectinas/metabolismo , Glutationa/genética , Glutationa/metabolismo , Células HEK293 , Humanos , Lipase Lipoproteica/genética , Lipase Lipoproteica/metabolismo , Proteínas de Membrana/genética , Oxirredução , Proteômica , Receptores de LDL/genética , Receptores de LDL/metabolismoRESUMO
BACKGROUND: Over 90% of skin cancers including cutaneous melanoma (CM) are related directly to sun exposure. Despite extensive knowledge on ultraviolet radiation's (UVR) detrimental impact, many still fail to implement sun protection/sun avoidance. Human behavior, attitudes, and cultural norms of individuals and communities heavily depend on the surrounding climate/environment. In many instances, the climate shapes the culture/norms of the society. Canada has vast geographic/environmental differences. METHODS: In the current ecological study, we sought to examine the relationship between various geographic and environmental factors and the distribution of CM incidence by Forward Sortation Area (FSA) postal code across Canada. CM incidence data were extracted from the Canadian Cancer Registry, while environmental data were extracted from the Canadian Urban Environmental Health Research Consortium (greenspace, as measured by the normalized difference vegetation index; annual highest temperature; absolute number and average length of yearly heat events; annual total precipitation [rain and snow]; absolute number and average length of events with precipitation [rain and snow]; and summer UVR index). The above geographic/environmental data by FSA were correlated with the respective CM incidence employing negative binomial regression model. RESULTS: Our analysis highlights that increases in annual average temperature, summer UVR, and greenspace were associated with higher expected incidence of CM cases, while higher number of annual heat events together with highest annual temperature and higher average number of annual rain events were associated with a decrease in CM incidence rate. This study also highlights regional variation in environmental CM risk factors in Canada. CONCLUSIONS: This national population-based study presents clinically relevant conclusions on weather/geographic variations associated with CM incidence in Canada and will help refine targeted CM prevention campaigns by understanding unique weather/geographic variations in high-risk regions.
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Melanoma , Neoplasias Cutâneas , Humanos , Melanoma/epidemiologia , Melanoma/etiologia , Melanoma/prevenção & controle , Neoplasias Cutâneas/epidemiologia , Neoplasias Cutâneas/etiologia , Neoplasias Cutâneas/prevenção & controle , Incidência , Raios Ultravioleta/efeitos adversos , Canadá/epidemiologia , Melanoma Maligno CutâneoRESUMO
Maintaining the long-term sustainability of human and natural systems across agricultural landscapes requires an integrated, systematic monitoring system that can track crop productivity and the impacts of agricultural intensification on natural resources. This study presents the design and practical implementation of a monitoring framework that combines satellite observations with ground-based biophysical measurements and household surveys to provide metrics on ecosystem services and agricultural production at multiple spatial scales, reaching from individual households and plots owned by smallholder farmers to 100-km2 landscapes. We developed a set of protocols for monitoring and analyzing ecological and agricultural household parameters within two 10 × 10-km landscapes in Rwanda, including soil fertility, crop yield, water availability, and fuelwood sustainability. Initial results suggest providing households that rely on rainfall for crop irrigation with timely climate information and improved technical inputs pre-harvest could help increase crop productivity in the short term. The value of the monitoring system is discussed as an effective tool for establishing a baseline of ecosystem services and agriculture before further change in land use and climate, identifying limitations in crop production and soil fertility, and evaluating food security, economic development, and environmental sustainability goals set forth by the Rwandan government.
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Conservação dos Recursos Naturais/métodos , Ecossistema , Monitoramento Ambiental/métodos , Agricultura/métodos , Clima , Ecologia , Abastecimento de Alimentos , Humanos , Ruanda , SoloRESUMO
Over a third of the US adult population has hypertriglyceridemia, resulting in an increased risk of atherosclerosis, pancreatitis, and metabolic syndrome. Lipoprotein lipase (LPL), a dimeric enzyme, is the main lipase responsible for TG clearance from the blood after food intake. LPL requires an endoplasmic reticulum (ER)-resident, transmembrane protein known as lipase maturation factor 1 (LMF1) for secretion and enzymatic activity. LMF1 is believed to act as a client specific chaperone for dimeric lipases, but the precise mechanism by which LMF1 functions is not understood. Here, we examine which domains of LMF1 contribute to dimeric lipase maturation by assessing the function of truncation variants. N-terminal truncations of LMF1 show that all the domains are necessary for LPL maturation. Fluorescence microscopy and protease protection assays confirmed that these variants were properly oriented in the ER. We measured cellular levels of LMF1 and found that it is expressed at low levels and each molecule of LMF1 promotes the maturation of 50 or more molecules of LPL. Thus we provide evidence for the critical role of the N-terminus of LMF1 for the maturation of LPL and relevant ratio of chaperone to substrate.
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Lipase Lipoproteica/química , Lipase Lipoproteica/metabolismo , Proteínas de Membrana/química , Proteínas de Membrana/metabolismo , Frações Subcelulares/química , Frações Subcelulares/metabolismo , Sequência de Aminoácidos , Ativação Enzimática , Humanos , Proteínas de Membrana/isolamento & purificação , Dados de Sequência Molecular , Estrutura Terciária de Proteína , Relação Estrutura-AtividadeRESUMO
Although the association between cognitive performances and the onset of psychiatric disorders has been widely investigated, limited research on the role of childhood trauma or early life stress (CT/ELS), and whether this role differs between clinical and non-clinical cohorts is available. This systematic review aims at filling this gap, testing whether the occurrence of CT/ELS and its subtypes are associated with cognitive domains (general cognitive ability, executive functions, working memory, attention, processing speed, verbal/visual memory) in patients with psychiatric disorders and in non-clinical populations. This study followed the PRISMA 2020 guidelines and the Newcastle-Ottawa scale for quality assessment. The search was performed until May 2022. Seventy-four studies were classified as eligible. The graphical representations of the results reported an association between exposure to CT/ELS and worse general cognitive ability, verbal/visual memory, processing speed and attention in patients affected by anxiety, mood and psychotic disorders, and that specific CT/ELS subtypes (physical neglect, physical/sexual abuse) can differentially influence specific cognitive abilities (executive functions, attention, working memory, verbal/visual memory). In non-clinical cohorts we found associations between CT/ELS exposure and impairments in executive functions, processing speed and working memory, while physical neglect was related to general cognitive ability and working memory. Concerning the emotional abuse/neglect subtypes in both populations, the results indicated their involvement in cognitive functioning; however, the few studies conducted are not enough to reach definitive conclusions. These findings suggest an association of CT/ELS with specific cognitive deficits and psychopathology.
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Adherence to lifestyle changes is a major challenge for healthcare professionals. The transtheoretical model (TTM) was proposed to promote behavioral changes, used in different health conditions (smoking, alcoholism, drug addiction, and obesity) and age groups. However, the effectiveness of the model in older persons is not yet known. This systematic review protocol follows the PRISMA-P guidance. The question the review will address is, Are interventions based on the TTM, compared with conventional interventions, associated with lifestyle changes in older adults? Databases MEDLINE/PubMed, EMBASE, LILACS, CENTRAL, WoS, and PsycINFO will be searched. Randomized clinical controlled trials and quasi-experimental studies describing the effectiveness of TTM-based interventions in changing the lifestyle of individuals aged 65 and over, compared with conventional interventions for lifestyle changes, will be included. Studies that do not address the stages of change characteristic of TTM or that use pharmacological interventions as a comparator will be excluded. Reviewers independently will screen papers for eligibility criteria, and, extracting data, assess the risk of bias for included studies and will evaluate the overall quality of evidence (GRADE system). If possible, a meta-analysis will be conducted. Otherwise, a narrative synthesis will be prepared according to the SWiM guideline.
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Alcoolismo , Estilo de Vida , Obesidade , Fumar , Transtornos Relacionados ao Uso de Substâncias , Modelo Transteórico , Idoso , Idoso de 80 Anos ou mais , Humanos , Metanálise como Assunto , Revisões Sistemáticas como AssuntoRESUMO
Genomic instability is a defining characteristic of cancer and the analysis of DNA damage at the chromosome level is a crucial part of the study of carcinogenesis and genotoxicity. Chromosomal instability (CIN), the most common level of genomic instability in cancers, is defined as the rate of loss or gain of chromosomes through successive divisions. As such, DNA in cancer cells is highly unstable. However, the underlying mechanisms remain elusive. There is a debate as to whether instability succeeds transformation, or if it is a by-product of cancer, and therefore, studying potential molecular and cellular contributors of genomic instability is of high importance. Recent work has suggested an important role for ectopic expression of meiosis genes in driving genomic instability via a process called meiomitosis. Improving understanding of these mechanisms can contribute to the development of targeted therapies that exploit DNA damage and repair mechanisms. Here, we discuss a workflow of novel and established techniques used to assess chromosomal instability as well as the nature of genomic instability such as double strand breaks, micronuclei, and chromatin bridges. For each technique, we discuss their advantages and limitations in a lab setting. Lastly, we provide detailed protocols for the discussed techniques.
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Background: Atopic dermatitis is a chronic, relapsing and remitting disease that can be difficult to treat despite a recently approved biologic therapy targeting IL-4/IL-13 receptor. Oral janus kinase inhibitors (JAKi) represent a novel therapeutic class of targeted therapy to treat moderate-to-severe atopic dermatitis (AD). Objective: To review the efficacy, safety, and pharmacokinetic characteristics of oral JAKi in the treatment of AD. Methods: A PRISMA systematic review was conducted using MEDLINE, EMBASE (Ovid), and PubMed databases for studies assessing the efficacy, safety, and/or pharmacokinetic properties of oral forms of JAKi in the treatment of AD in pediatric or adult populations from inception to June 2021. Results: 496 papers were reviewed. Of 28 articles that underwent full text screening, 11 met our inclusion criteria for final qualitative review. Four studies examined abrocitinib; three studies examined baricitinib; three examined upadacitinib and one examined gusacitinib (ASN002). Significant clinical efficacy and a reassuring safety profile was reported for all JAKi agents reviewed. Rapid symptom control was reported for abrocitinib, baricitinib and upadacitinib. Limitations: Given the relatively limited evidence for each JAKi and the differences in patient eligibility criteria between studies, the data was not deemed suitable for a meta-analysis at this time. Conclusion: Given their ability to achieve rapid symptom control with a reassuring safety profile, we recommend considering the use of JAKi as a reliable systemic treatment option for adult patients with moderate-to-severe AD, who are unresponsive to topical or skin directed treatments.
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CONTEXT: Pneumococcal conjugate vaccines (PCVs) (pneumococcal 13-valent conjugate vaccine [PCV-13] and pneumococcal 10-valent conjugate vaccine [PCV-10]) are available for prevention of pneumococcal infections in children. OBJECTIVE: To determine the vaccine effectiveness (VE) of PCV-13 and PCV-10 in preventing invasive pneumococcal disease (IPD) and acute otitis media (AOM) in children <5 years. DATA SOURCES: Systematic searches of Medline, Embase, Cumulative Index to Nursing and Allied Health Literature, Web of Science, and Cochrane. STUDY SELECTION: Eligible studies examined the direct effectiveness and/or efficacy of PCV-10 and PCV-13 in reducing the incidence of disease in healthy children <5 years. DATA EXTRACTION: Two reviewers independently conducted data extraction and methodologic quality assessment. RESULTS: Significant effectiveness against vaccine-type IPD in children ≤5 years was reported for ≥1 dose of PCV-13 in the 3 + 1 (86%-96%) and 2 + 1 schedule (67.2%-86%) and for PCV-10 for the 3 + 1 (72.8%-100%) and 2 + 1 schedules (92%-97%). In children <12 months of age, PCV-13 VE against serotype 19A post-primary series was significant for the 3 + 1 but not the 2 + 1 schedule. PCV-10 crossprotection against 19A was significant in children ≤5 years with ≥1 dose (82.2% and 71%). Neither PCVs were found effective against serotype 3. PCV-13 was effective against AOM (86%; 95% confidence interval [CI]: 61 to 94). PCV-10 was effective against clinically defined (26.9%; 95% CI: 5.9 to 43.3) and bacteriologically confirmed AOM (43.3%; 95% CI: 1.7 to 67.3). LIMITATIONS: Because of the large heterogeneity in studies, a meta-analysis for pooled estimates was not done. CONCLUSIONS: Both PCVs afford protection against pneumococcal infections, with PCV-10 protecting against 19A IPD, but this VE has not been verified in the youngest age groups.
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Otite Média/prevenção & controle , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas/uso terapêutico , Doença Aguda , Pré-Escolar , Intervalos de Confiança , Humanos , Esquemas de Imunização , Lactente , Sorotipagem , Streptococcus/classificação , Vacinas Conjugadas/uso terapêuticoRESUMO
Medium-to-large mammals within tropical forests represent a rich and functionally diversified component of this biome; however, they continue to be threatened by hunting and habitat loss. Assessing these communities implies studying species' richness and composition, and determining a state variable of species abundance in order to infer changes in species distribution and habitat associations. The Tropical Ecology, Assessment and Monitoring (TEAM) network fills a chronic gap in standardized data collection by implementing a systematic monitoring framework of biodiversity, including mammal communities, across several sites. In this study, we used TEAM camera trap data collected in the Udzungwa Mountains of Tanzania, an area of exceptional importance for mammal diversity, to propose an example of a baseline assessment of species' occupancy. We used 60 camera trap locations and cumulated 1,818 camera days in 2009. Sampling yielded 10,647 images of 26 species of mammals. We estimated that a minimum of 32 species are in fact present, matching available knowledge from other sources. Estimated species richness at camera sites did not vary with a suite of habitat covariates derived from remote sensing, however the detection probability varied with functional guilds, with herbivores being more detectable than other guilds. Species-specific occupancy modelling revealed novel ecological knowledge for the 11 most detected species, highlighting patterns such as 'montane forest dwellers', e.g. the endemic Sanje mangabey (Cercocebus sanjei), and 'lowland forest dwellers', e.g. suni antelope (Neotragus moschatus). Our results show that the analysis of camera trap data with account for imperfect detection can provide a solid ecological assessment of mammal communities that can be systematically replicated across sites.