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Hippocampal activity represents many behaviorally important variables, including context, an animal's location within a given environmental context, time, and reward. Using longitudinal calcium imaging in mice, multiple large virtual environments, and differing reward contingencies, we derived a unified probabilistic model of CA1 representations centered on a single feature-the field propensity. Each cell's propensity governs how many place fields it has per unit space, predicts its reward-related activity, and is preserved across distinct environments and over months. Propensity is broadly distributed-with many low, and some very high, propensity cells-and thus strongly shapes hippocampal representations. This results in a range of spatial codes, from sparse to dense. Propensity varied â¼10-fold between adjacent cells in salt-and-pepper fashion, indicating substantial functional differences within a presumed cell type. Intracellular recordings linked propensity to cell excitability. The stability of each cell's propensity across conditions suggests this fundamental property has anatomical, transcriptional, and/or developmental origins.
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Hipocampo/anatomía & histología , Hipocampo/fisiología , Animales , Conducta Animal/fisiología , Fenómenos Biofísicos , Calcio/metabolismo , Masculino , Ratones Endogámicos C57BL , Modelos Neurológicos , Células Piramidales/fisiología , Recompensa , Análisis y Desempeño de Tareas , Factores de TiempoRESUMEN
Bats harbor many viruses asymptomatically, including several notorious for causing extreme virulence in humans. To identify differences between antiviral mechanisms in humans and bats, we sequenced, assembled, and analyzed the genome of Rousettus aegyptiacus, a natural reservoir of Marburg virus and the only known reservoir for any filovirus. We found an expanded and diversified KLRC/KLRD family of natural killer cell receptors, MHC class I genes, and type I interferons, which dramatically differ from their functional counterparts in other mammals. Such concerted evolution of key components of bat immunity is strongly suggestive of novel modes of antiviral defense. An evaluation of the theoretical function of these genes suggests that an inhibitory immune state may exist in bats. Based on our findings, we hypothesize that tolerance of viral infection, rather than enhanced potency of antiviral defenses, may be a key mechanism by which bats asymptomatically host viruses that are pathogenic in humans.
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Quirópteros/genética , Genoma , Inmunidad Innata/genética , Secuencia de Aminoácidos , Animales , Línea Celular , Quirópteros/clasificación , Quirópteros/inmunología , Mapeo Cromosómico , Reservorios de Enfermedades/virología , Egipto , Evolución Molecular , Variación Genética , Antígenos de Histocompatibilidad Clase I/clasificación , Antígenos de Histocompatibilidad Clase I/genética , Humanos , Interferón Tipo I/clasificación , Interferón Tipo I/genética , Enfermedad del Virus de Marburg/inmunología , Enfermedad del Virus de Marburg/patología , Marburgvirus/fisiología , Subfamília C de Receptores Similares a Lectina de Células NK/química , Subfamília C de Receptores Similares a Lectina de Células NK/clasificación , Subfamília C de Receptores Similares a Lectina de Células NK/genética , Subfamília D de Receptores Similares a Lectina de las Células NK/química , Subfamília D de Receptores Similares a Lectina de las Células NK/clasificación , Subfamília D de Receptores Similares a Lectina de las Células NK/genética , Filogenia , Alineación de SecuenciaRESUMEN
Neurons are well suited for computations on millisecond timescales, but some neuronal circuits set behavioral states over long time periods, such as those involved in energy homeostasis. We found that multiple types of hypothalamic neurons, including those that oppositely regulate body weight, are specialized as near-perfect synaptic integrators that summate inputs over extended timescales. Excitatory postsynaptic potentials (EPSPs) are greatly prolonged, outlasting the neuronal membrane time-constant up to 10-fold. This is due to the voltage-gated sodium channel Nav1.7 (Scn9a), previously associated with pain-sensation but not synaptic integration. Scn9a deletion in AGRP, POMC, or paraventricular hypothalamic neurons reduced EPSP duration, synaptic integration, and altered body weight in mice. In vivo whole-cell recordings in the hypothalamus confirmed near-perfect synaptic integration. These experiments show that integration of synaptic inputs over time by Nav1.7 is critical for body weight regulation and reveal a mechanism for synaptic control of circuits regulating long term homeostatic functions.
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Mantenimiento del Peso Corporal , Hipotálamo/citología , Canal de Sodio Activado por Voltaje NAV1.7/metabolismo , Neuronas/metabolismo , Sinapsis , Proteína Relacionada con Agouti/metabolismo , Animales , Homeostasis , Hipotálamo/metabolismo , Masculino , Ratones , Ratones TransgénicosRESUMEN
The claustrum is one of the most widely connected regions of the forebrain, yet its function has remained obscure, largely due to the experimentally challenging nature of targeting this small, thin, and elongated brain area. However, recent advances in molecular techniques have enabled the anatomy and physiology of the claustrum to be studied with the spatiotemporal and cell type-specific precision required to eventually converge on what this area does. Here we review early anatomical and electrophysiological results from cats and primates, as well as recent work in the rodent, identifying the connectivity, cell types, and physiological circuit mechanisms underlying the communication between the claustrum and the cortex. The emerging picture is one in which the rodent claustrum is closely tied to frontal/limbic regions and plays a role in processes, such as attention, that are associated with these areas.
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Ganglios Basales/fisiología , Corteza Cerebral/anatomía & histología , Corteza Cerebral/fisiología , Claustro/anatomía & histología , Vías Nerviosas/fisiología , Animales , Ganglios Basales/anatomía & histología , Claustro/fisiopatología , Lóbulo Frontal/anatomía & histología , Lóbulo Frontal/fisiología , Corteza Prefrontal/anatomía & histología , Corteza Prefrontal/fisiologíaRESUMEN
Cytosolic sensing of nucleic acids initiates tightly regulated programs to limit infection. Oocyte fertilization represents a scenario wherein inappropriate responses to exogenous yet non-pathogen-derived nucleic acids would have negative consequences. We hypothesized that germ cells express negative regulators of nucleic acid sensing (NAS) in steady state and applied an integrated data-mining and functional genomics approach to identify a rheostat of DNA and RNA sensing-the inflammasome component NLRP14. We demonstrated that NLRP14 interacted physically with the nucleic acid sensing pathway and targeted TBK1 (TANK binding kinase 1) for ubiquitination and degradation. We further mapped domains in NLRP14 and TBK1 that mediated the inhibitory function. Finally, we identified a human nonsense germline variant associated with male sterility that results in loss of NLRP14 function and hyper-responsiveness to nucleic acids. The discovery points to a mechanism of nucleic acid sensing regulation that may be of particular importance in fertilization.
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Fertilización/inmunología , Células Germinativas/inmunología , Inflamasomas/inmunología , Ácidos Nucleicos/inmunología , Nucleósido-Trifosfatasa/inmunología , Células A549 , Animales , Chlorocebus aethiops , Citosol/inmunología , Citosol/metabolismo , Femenino , Fertilización/genética , Expresión Génica/inmunología , Células Germinativas/metabolismo , Mutación de Línea Germinal/inmunología , Células HEK293 , Humanos , Immunoblotting , Infertilidad Masculina/genética , Infertilidad Masculina/inmunología , Inflamasomas/genética , Inflamasomas/metabolismo , Masculino , Ácidos Nucleicos/metabolismo , Nucleósido-Trifosfatasa/genética , Nucleósido-Trifosfatasa/metabolismo , Unión Proteica/inmunología , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/inmunología , Proteínas Serina-Treonina Quinasas/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal/genética , Transducción de Señal/inmunología , Células VeroRESUMEN
Insoluble cytoplasmic aggregate formation of the RNA-binding protein TDP-43 is a major hallmark of neurodegenerative diseases including Amyotrophic Lateral Sclerosis. TDP-43 localizes predominantly in the nucleus, arranging itself into dynamic condensates through liquid-liquid phase separation (LLPS). Mutations and post-translational modifications can alter the condensation properties of TDP-43, contributing to the transition of liquid-like biomolecular condensates into solid-like aggregates. However, to date it has been a challenge to study the dynamics of this process in vivo. We demonstrate through live imaging that human TDP-43 undergoes nuclear condensation in spinal motor neurons in a living animal. RNA-binding deficiencies as well as post-translational modifications can lead to aberrant condensation and altered TDP-43 compartmentalization. Single-molecule tracking revealed an altered mobility profile for RNA-binding deficient TDP-43. Overall, these results provide a critically needed in vivo characterization of TDP-43 condensation, demonstrate phase separation as an important regulatory mechanism of TDP-43 accessibility, and identify a molecular mechanism of how functional TDP-43 can be regulated.
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Proteínas de Unión al ADN , Neuronas Motoras , Proteínas de Unión al ARN , Animales , Humanos , Ratones , Esclerosis Amiotrófica Lateral/metabolismo , Esclerosis Amiotrófica Lateral/genética , Condensados Biomoleculares/metabolismo , Núcleo Celular/metabolismo , Proteínas de Unión al ADN/metabolismo , Proteínas de Unión al ADN/genética , Homeostasis , Neuronas Motoras/metabolismo , Mutación , Unión Proteica , Procesamiento Proteico-Postraduccional , ARN/metabolismo , ARN/genética , Proteínas de Unión al ARN/metabolismo , Proteínas de Unión al ARN/genéticaRESUMEN
Spinocerebellar ataxia type 3 (SCA3, also known as Machado Joseph disease) is a fatal neurodegenerative disease caused by the expansion of the trinucleotide repeat region within the ATXN3/MJD gene. Mutation of ATXN3 causes formation of ataxin-3 protein aggregates, neurodegeneration, and motor deficits. Here we investigated the therapeutic potential and mechanistic activity of sodium butyrate (SB), the sodium salt of butyric acid, a metabolite naturally produced by gut microbiota, on cultured SH-SY5Y cells and transgenic zebrafish expressing human ataxin-3 containing 84 glutamine (Q) residues to model SCA3. SCA3 SH-SY5Y cells were found to contain high molecular weight ataxin-3 species and detergent-insoluble protein aggregates. Treatment with SB increased the activity of the autophagy protein quality control pathway in the SCA3 cells, decreased the presence of ataxin-3 aggregates and presence of high molecular weight ataxin-3 in an autophagy-dependent manner. Treatment with SB was also beneficial in vivo, improving swimming performance, increasing activity of the autophagy pathway, and decreasing the presence of insoluble ataxin-3 protein species in the transgenic SCA3 zebrafish. Co-treating the SCA3 zebrafish with SB and chloroquine, an autophagy inhibitor, prevented the beneficial effects of SB on zebrafish swimming, indicating that the improved swimming performance was autophagy-dependent. To understand the mechanism by which SB induces autophagy we performed proteomic analysis of protein lysates from the SB-treated and untreated SCA3 SH-SY5Y cells. We found that SB treatment had increased activity of Protein Kinase A and AMPK signaling, with immunoblot analysis confirming that SB treatment had increased levels of AMPK protein and its substrates. Together our findings indicate that treatment with SB can increase activity of the autophagy pathway process and that this has beneficial effects in vitro and in vivo. While our results suggested that this activity may involve activity of a PKA/AMPK-dependent process, this requires further confirmation. We propose that treatment with sodium butyrate warrants further investigation as a potential treatment for neurodegenerative diseases underpinned by mechanisms relating to protein aggregation including SCA3.
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Enfermedad de Machado-Joseph , Neuroblastoma , Enfermedades Neurodegenerativas , Humanos , Animales , Ácido Butírico/farmacología , Ataxina-3/genética , Enfermedad de Machado-Joseph/tratamiento farmacológico , Enfermedad de Machado-Joseph/genética , Pez Cebra , Proteínas Quinasas Activadas por AMP , Agregado de Proteínas , Proteómica , Autofagia , Animales Modificados Genéticamente , Proteínas Quinasas Dependientes de AMP CíclicoRESUMEN
Machado-Joseph disease (MJD) is a devastating and incurable neurodegenerative disease characterised by progressive ataxia, difficulty speaking and swallowing. Consequently, affected individuals ultimately become wheelchair dependent, require constant care, and face a shortened life expectancy. The monogenic cause of MJD is expansion of a trinucleotide (CAG) repeat region within the ATXN3 gene, which results in polyglutamine (polyQ) expansion within the resultant ataxin-3 protein. While it is well established that the ataxin-3 protein functions as a deubiquitinating (DUB) enzyme and is therefore critically involved in proteostasis, several unanswered questions remain regarding the impact of polyQ expansion in ataxin-3 on its DUB function. Here we review the current literature surrounding ataxin-3's DUB function, its DUB targets, and what is known regarding the impact of polyQ expansion on ataxin-3's DUB function. We also consider the potential neuroprotective effects of ataxin-3's DUB function, and the intersection of ataxin-3's role as a DUB enzyme and regulator of gene transcription. Ataxin-3 is the principal pathogenic protein in MJD and also appears to be involved in cancer. As aberrant deubiquitination has been linked to both neurodegeneration and cancer, a comprehensive understanding of ataxin-3's DUB function is important for elucidating potential therapeutic targets in these complex conditions. In this review, we aim to consolidate knowledge of ataxin-3 as a DUB and unveil areas for future research to aid therapeutic targeting of ataxin-3's DUB function for the treatment of MJD and other diseases.
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Enfermedad de Machado-Joseph , Neoplasias , Enfermedades Neurodegenerativas , Humanos , Ataxina-3/genética , Ataxina-3/metabolismo , Enfermedad de Machado-Joseph/genética , Enfermedad de Machado-Joseph/metabolismo , Enfermedad de Machado-Joseph/patología , Enfermedades Neurodegenerativas/genéticaRESUMEN
Signaling through the Ras-MAPK pathway can exhibit switch-like activation, which has been attributed to the underlying positive feedback and bimodality in the activation of RasGDP to RasGTP by SOS. SOS contains both catalytic and allosteric Ras binding sites, and a common assumption is that allosteric activation selectively by RasGTP provides the mechanism of positive feedback. However, recent single-molecule studies have revealed that SOS catalytic rates are independent of the nucleotide state of Ras in the allosteric binding site, raising doubt about this as a positive feedback mechanism. Here, we perform detailed kinetic analyses of receptor-mediated recruitment of full-length SOS to the membrane while simultaneously monitoring its catalytic activation of Ras. These results, along with kinetic modeling, expose the autoinhibition release step in SOS, rather than either recruitment or allosteric activation, as the underlying mechanism giving rise to positive feedback in Ras activation.
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Finding effective therapeutic targets to treat NRAS-mutated melanoma remains a challenge. Long non-coding RNAs (lncRNAs) recently emerged as essential regulators of tumorigenesis. Using a discovery approach combining experimental models and unbiased computational analysis complemented by validation in patient biospecimens, we identified a nuclear-enriched lncRNA (AC004540.4) that is upregulated in NRAS/MAPK-dependent melanoma, and that we named T-RECS. Considering potential innovative treatment strategies, we designed antisense oligonucleotides (ASOs) to target T-RECS. T-RECS ASOs reduced the growth of melanoma cells and induced apoptotic cell death, while having minimal impact on normal primary melanocytes. Mechanistically, treatment with T-RECS ASOs downregulated the activity of pro-survival kinases and reduced the protein stability of hnRNPA2/B1, a pro-oncogenic regulator of MAPK signaling. Using patient- and cell line- derived tumor xenograft mouse models, we demonstrated that systemic treatment with T-RECS ASOs significantly suppressed the growth of melanoma tumors, with no noticeable toxicity. ASO-mediated T-RECS inhibition represents a promising RNA-targeting approach to improve the outcome of MAPK pathway-activated melanoma.
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Melanoma , ARN Largo no Codificante , Humanos , Ratones , Animales , Melanoma/patología , ARN Largo no Codificante/genética , Apoptosis/genética , Oligonucleótidos Antisentido/genética , Oligonucleótidos Antisentido/uso terapéutico , Línea Celular Tumoral , Proteínas de la Membrana/genética , GTP Fosfohidrolasas/genética , GTP Fosfohidrolasas/metabolismoRESUMEN
Previously, we demonstrated that the SCFcyclin F complex directly mediates the poly-ubiquitylation of TDP-43, raising the question of whether cyclin F can be used to enhance the turnover of TDP-43. A hurdle to the use of cyclin F, however, is that the overexpression of cyclin F can lead to the initiation of cell death pathways. Accordingly, the aim of this study was to identify and evaluate a less toxic variant of cyclin F. To do so, we first confirmed and validated our previous findings that cyclin F binds to TDP-43 in an atypical manner. Additionally, we demonstrated that mutating the canonical substrate region in cyclin F (to generate cyclin FMRL/AAA) led to reduced binding affinity to known canonical substrates without impacting the interaction between cyclin F and TDP-43. Notably, both wild-type and cyclin FMRL/AAA effectively reduced the abundance of TDP-43 in cultured cells whilst cyclin FMRL/AAA also demonstrated reduced cell death compared to the wild-type control. The decrease in toxicity also led to a reduction in morphological defects in zebrafish embryos. These results suggest that cyclin F can be modified to enhance its targeting of TDP-43, which in turn reduces the toxicity associated with the overexpression of cyclin F. This study provides greater insights into the interaction that occurs between cyclin F and TDP-43 in cells and in vivo.
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Esclerosis Amiotrófica Lateral , Animales , Esclerosis Amiotrófica Lateral/metabolismo , Pez Cebra , Proteínas de Unión al ADN/metabolismo , Ubiquitinación , Ciclinas/genética , Ciclinas/metabolismoRESUMEN
OBJECTIVE: To determine whether health-related physical fitness and body mass index (BMI) status differed before and after school closure from the COVID-19 pandemic in a population-based cohort of Hong Kong primary schoolchildren. STUDY DESIGN: We examined the BMI z score, BMI status, and physical fitness z scores including (i) upper limb muscle strength, (ii) 1-minute sit-up test, (iii) sit-and-reach test, and (iv) endurance run tests, among 3 epochs: prepandemic (September 2018-August 2019), before school closure (September 2019-January 2020), and partial school reopening (September 2021-August 2022), using a repeated cross-sectional approach. RESULTS: A total of 137â752 primary schoolchildren aged 6-12 years were recruited over 3 academic years. Obesity increased significantly from 25.9% in 2018/19 to 31.0% in 2021/22, while underweight increased slightly from 6.1% to 6.5%. All tested parameters were adversely affected by the pandemic. The negative trend over time was far more pronounced in all 4 physical fitness scores in the underweight group, although performance in handgrip strength had no significance between 2018/19 and 2021/22. CONCLUSIONS: Schoolchildren who are both underweight and overweight/obese are vulnerable to adverse changes in physical fitness during the COVID-19 pandemic. To eliminate the negative health and fitness outcomes, it is urgent to develop strategies for assisting schoolchildren in achieving a healthy weight, especially in the postpandemic era.
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COVID-19 , Pandemias , Humanos , Niño , Índice de Masa Corporal , Delgadez/epidemiología , Hong Kong/epidemiología , Fuerza de la Mano , COVID-19/epidemiología , Aptitud Física/fisiología , Sobrepeso/epidemiología , Obesidad , Instituciones AcadémicasRESUMEN
Molybdenum carbide MXenes have garnered considerable attention in electronics, energy storage, and catalysis. However, they are prone to oxidative degradation, but the associated mechanisms have not been systematically explored. Therefore, the oxidation mechanisms of Mo-based single-metallic/bimetallic carbide MXenes including Mo2CTx, Mo2TiC2Tx, and Mo2Ti2C3Tx in aqueous suspensions were investigated for the first time in this study. Similar to Ti3C2Tx MXene, Mo-based MXenes were found to undergo oxidative degradation in their aqueous dispersions, leading to the disruption of their crystal structure and subsequent loss of optical and electronic properties. Notably, the Mo2CTx MXene deviated from this typical oxidation behavior as it produced an amorphous product with Mo ions instead of highly crystalline Mo-oxides during oxidation. Similarly, the Mo2TiC2Tx and Mo2Ti2C3Tx MXenes did not yield crystalline Mo-oxides; instead, they produced highly crystalline anatase TiO2 and a Mo-ion-containing amorphous product simultaneously. Furthermore, high-temperature annealing of the oxidized Mo2CTx MXene powder at 800 °C transformed the amorphous Mo-containing product into highly crystalline MoO2 crystals. These findings highlight the unconventional oxidation behavior of Mo-based MXenes, which suggests that the formation of crystalline Mo-based oxides requires a higher activation energy during oxidation than that of TiO2. The unique oxidative pathway reported herein can help elucidate the oxidation mechanisms of Mo-based MXene dispersions and their products. The insights from this study can pave the way for fundamental studies in academia as well as broaden the applications of Mo-based MXenes in various industries.
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BACKGROUND: Genetic surveillance of the Plasmodium falciparum parasite shows great promise for helping National Malaria Control Programmes (NMCPs) assess parasite transmission. Genetic metrics such as the frequency of polygenomic (multiple strain) infections, genetic clones, and the complexity of infection (COI, number of strains per infection) are correlated with transmission intensity. However, despite these correlations, it is unclear whether genetic metrics alone are sufficient to estimate clinical incidence. METHODS: This study examined parasites from 3147 clinical infections sampled between the years 2012-2020 through passive case detection (PCD) across 16 clinic sites spread throughout Senegal. Samples were genotyped with a 24 single nucleotide polymorphism (SNP) molecular barcode that detects parasite strains, distinguishes polygenomic (multiple strain) from monogenomic (single strain) infections, and identifies clonal infections. To determine whether genetic signals can predict incidence, a series of Poisson generalized linear mixed-effects models were constructed to predict the incidence level at each clinical site from a set of genetic metrics designed to measure parasite clonality, superinfection, and co-transmission rates. RESULTS: Model-predicted incidence was compared with the reported standard incidence data determined by the NMCP for each clinic and found that parasite genetic metrics generally correlated with reported incidence, with departures from expected values at very low annual incidence (< 10/1000/annual []). CONCLUSIONS: When transmission is greater than 10 cases per 1000 annual parasite incidence (annual incidence > 10), parasite genetics can be used to accurately infer incidence and is consistent with superinfection-based hypotheses of malaria transmission. When transmission was < 10, many of the correlations between parasite genetics and incidence were reversed, which may reflect the disproportionate impact of importation and focal transmission on parasite genetics when local transmission levels are low.
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Malaria , Sobreinfección , Humanos , Senegal/epidemiología , Incidencia , Plasmodium falciparum/genéticaRESUMEN
Here, we present detailed kinetic analyses of a panel of soluble lipid kinases and phosphatases, as well as Ras activating proteins, acting on their respective membrane surface substrates. The results reveal that the mean catalytic rate of such interfacial enzymes can exhibit a strong dependence on the size of the reaction system-in this case membrane area. Experimental measurements and kinetic modeling reveal how stochastic effects stemming from low molecular copy numbers of the enzymes alter reaction kinetics based on mechanistic characteristics of the enzyme, such as positive feedback. For the competitive enzymatic cycles studied here, the final product-consisting of a specific lipid composition or Ras activity state-depends on the size of the reaction system. Furthermore, we demonstrate how these reaction size dependencies can be controlled by engineering feedback mechanisms into the enzymes.
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Tamaño de la Célula , Enzimas/metabolismo , Membranas/fisiología , Retroalimentación , Cinética , Membrana Dobles de Lípidos , Lípidos , Modelos Biológicos , Monoéster Fosfórico Hidrolasas , Transducción de SeñalRESUMEN
BACKGROUND: This cross-sectional study aimed to investigate the association between negative mental health conditions and demographic characteristics, socioeconomic background and health-related parameters in both Hong Kong's primary and secondary school students. METHODS: A self-administrated survey was conducted and investigated the prevalence of negative mental health conditions (psychological stress, depression and suicidality) in students from 30 primary schools and 25 secondary schools in Hong Kong in 2017. The Kessler Psychological Distress Scale (K6) was chosen as the instrument to evaluate non-specific psychological distress. Depression was evaluated using the prolonged feeling of despair as a proxy. Suicidality was measured by four questions on whether they had ever intentionally injured themselves, seriously considered attempting suicide, planned how they would attempt suicide and had attempted suicide. Multiple logistic regression models examined the explanatory factors' association with mental health conditions after adjusting for confounding, using the enter method. RESULTS: A total of 4884 responses were collected. It is found that both very high and low parent expectations were risk factors for multiple conditions, namely suicidality and psychological distress among primary school students, and psychological distress among secondary school students. As for primary school students, the experience of being bullied was a significant risk factor for all conditions. A significant association was found between having one's own bedroom and suicidality amongst primary school students; whilst having three close friends or more and higher life satisfaction levels were significantly associated with a lower risk of negative mental health conditions among secondary school students. CONCLUSIONS: It was found that having one's own bedroom was a risk factor for suicidality among primary school student. Parents should be alert to the risky behaviours of children, have more involvement in children's daily life and build a supportive and caring family environment for children. For secondary school students, as the importance of friends is greatly increased, teachers should encourage students to engage in extra-curricular activities in school.
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Salud Mental , Intento de Suicidio , Niño , Humanos , Hong Kong/epidemiología , Estudios Transversales , Intento de Suicidio/psicología , Ideación SuicidaRESUMEN
Progressive supranuclear palsy (PSP) is a late-onset neurodegenerative disease defined pathologically by the presence of insoluble phosphorylated-Tau (p-Tau) in neurons and glia. Identifying co-aggregating proteins within p-Tau inclusions may reveal important insights into processes affected by the aggregation of Tau. We used a proteomic approach, which combines antibody-mediated biotinylation and mass spectrometry (MS) to identify proteins proximal to p-Tau in PSP. Using this proof-of-concept workflow for identifying interacting proteins of interest, we characterized proteins proximal to p-Tau in PSP cases, identifying >84% of previously identified interaction partners of Tau and known modifiers of Tau aggregation, while 19 novel proteins not previously found associated with Tau were identified. Furthermore, our data also identified confidently assigned phosphorylation sites that have been previously reported on p-Tau. Additionally, using ingenuity pathway analysis (IPA) and human RNA-seq datasets, we identified proteins previously associated with neurological disorders and pathways involved in protein degradation, stress responses, cytoskeletal dynamics, metabolism, and neurotransmission. Together, our study demonstrates the utility of biotinylation by antibody recognition (BAR) approach to answer a fundamental question to rapidly identify proteins in proximity to p-Tau from post-mortem tissue. The application of this workflow opens up the opportunity to identify novel protein targets to give us insight into the biological process at the onset and progression of tauopathies.
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Enfermedades Neurodegenerativas , Parálisis Supranuclear Progresiva , Tauopatías , Humanos , Proteínas tau/metabolismo , Parálisis Supranuclear Progresiva/metabolismo , Proteolisis , Proteómica , Tauopatías/metabolismo , Transmisión SinápticaRESUMEN
Previously, we identified missense mutations in CCNF that are causative of familial and sporadic amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Hallmark features of these diseases include the build-up of insoluble protein aggregates as well as the mislocalization of proteins such as transactive response DNA binding protein 43 kDa (TDP-43). In recent years, the dysregulation of SFPQ (splicing factor proline and glutamine rich) has also emerged as a pathological hallmark of ALS/FTD. CCNF encodes for the protein cyclin F, a substrate recognition component of an E3 ubiquitin ligase. We have previously shown that ALS/FTD-linked mutations in CCNF cause disruptions to overall protein homeostasis that leads to a build-up of K48-linked ubiquitylated proteins as well as defects in autophagic machinery. To investigate further processes that may be affected by cyclin F, we used a protein-proximity ligation method, known as Biotin Identification (BioID), standard immunoprecipitations and mass spectrometry to identify novel interaction partners of cyclin F and infer further process that may be affected by the ALS/FTD-causing mutation. Results demonstrate that cyclin F closely associates with proteins involved with RNA metabolism as well as a number of RNA-binding proteins previously linked to ALS/FTD, including SFPQ. Notably, the overexpression of cyclin F(S621G) led to the aggregation and altered subcellular distribution of SFPQ in human embryonic kidney (HEK293) cells, while leading to altered degradation in primary neurons. Overall, our data links ALS/FTD-causing mutations in CCNF to converging pathological features of ALS/FTD and provides a link between defective protein degradation systems and the pathological accumulation of a protein involved in RNA processing and metabolism.
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Esclerosis Amiotrófica Lateral/genética , Ciclinas/genética , Demencia Frontotemporal/genética , Factor de Empalme Asociado a PTB/genética , Esclerosis Amiotrófica Lateral/metabolismo , Esclerosis Amiotrófica Lateral/patología , Proteínas de Unión al ADN/genética , Demencia Frontotemporal/metabolismo , Demencia Frontotemporal/patología , Células HEK293 , Humanos , Agregado de Proteínas/genética , Mapas de Interacción de Proteínas/genética , Proteolisis , ARN/genética , ARN/metabolismo , Procesamiento Postranscripcional del ARN/genética , Proteínas de Unión al ARN/genéticaRESUMEN
Thermoelectric technology, which has been receiving attention as a sustainable energy source, has limited applications because of its relatively low conversion efficiency. To broaden their application scope, thermoelectric materials require a high dimensionless figure of merit (ZT). Porous structuring of a thermoelectric material is a promising approach to enhance ZT by reducing its thermal conductivity. However, nanopores do not form in thermoelectric materials in a straightforward manner; impurities are also likely to be present in thermoelectric materials. Here, a simple but effective way to synthesize impurity-free nanoporous Bi0.4 Sb1.6 Te3 via the use of nanoporous raw powder, which is scalably formed by the selective dissolution of KCl after collision between Bi0.4 Sb1.6 Te3 and KCl powders, is proposed. This approach creates abundant nanopores, which effectively scatter phonons, thereby reducing the lattice thermal conductivity by 33% from 0.55 to 0.37 W m-1 K-1 . Benefitting from the optimized porous structure, porous Bi0.4 Sb1.6 Te3 achieves a high ZT of 1.41 in the temperature range of 333-373 K, and an excellent average ZT of 1.34 over a wide temperature range of 298-473 K. This study provides a facile and scalable method for developing high thermoelectric performance Bi2 Te3 -based alloys that can be further applied to other thermoelectric materials.
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Alkaline water electrolysis (AWE) is considered a promising technology for green hydrogen (H2 ) production. Conventional diaphragm-type porous membranes have a high risk of explosion owing to their high gas crossover, while nonporous anion exchange membranes lack mechanical and thermochemical stability, limiting their practical application. Herein, a thin film composite (TFC) membrane is proposed as a new category of AWE membranes. The TFC membrane consists of an ultrathin quaternary ammonium (QA) selective layer formed via Menshutkin reaction-based interfacial polymerization on a porous polyethylene (PE) support. The dense, alkaline-stable, and highly anion-conductive QA layer prevents gas crossover while promoting anion transport. The PE support reinforces the mechanical and thermochemical properties, while its highly porous and thin structure reduces mass transport resistance across the TFC membrane. Consequently, the TFC membrane exhibits unprecedentedly high AWE performance (1.16 A cm-2 at 1.8 V) using nonprecious group metal electrodes with a potassium hydroxide (25 wt%) aqueous solution at 80 °C, significantly outperforming commercial and other lab-made AWE membranes. Moreover, the TFC membrane demonstrates remarkably low gas crossover, long-term stability, and stack cell operability, thereby ensuring its commercial viability for green H2 production. This strategy provides an advanced material platform for energy and environmental applications.