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BACKGROUND: Learning from rewarded and punished choices is perturbed in depressed patients, suggesting that abnormal reinforcement learning may be a cognitive mechanism of the illness. However, previous studies have disagreed about whether this behavior is produced by alterations in the rate of learning or sensitivity to experienced outcomes. This previous work has generally assessed learning in response to binary outcomes of one valence, rather than to both rewarding and punishing continuous outcomes. METHODS: A novel drifting reward and punishment magnitude reinforcement-learning task was administered to patients with current (n = 40) and remitted depression (n = 39), and healthy volunteers (n = 40) to capture potential differences in learning behavior. Standard questionnaires were administered to measure self-reported depressive symptom severity, trait and state anxiety and level of anhedonic symptoms. RESULTS: Our findings demonstrate that patients with current depression adjust their learning behaviors to a lesser degree in response to trial-by-trial variations in reward and loss magnitudes than the other groups. Computational modeling revealed that this behavioral signature of current depressive state is better accounted for by reduced reward and punishment sensitivity (all p < 0.031), rather than a change in learning rate (p = 0.708). However, between-group differences were not related to self-reported symptom severity or comorbid anxiety disorders in the current depression group. CONCLUSION: These findings suggest that current depression is associated with reduced outcome sensitivity rather than altered learning rate. Previous findings reported in this domain mainly from binary learning tasks seem to generalize to learning from continuous outcomes.
Assuntos
Depressão , Reforço Psicológico , Humanos , Depressão/psicologia , Recompensa , Punição/psicologia , AnedoniaRESUMO
TM4SF20 (transmembrane 4 L6 family 20) is a polytopic membrane protein that inhibits proteolytic processing of CREB3L1 (cAMP response element-binding protein 3-like 1), a membrane-bound transcription factor that blocks cell division and activates collagen synthesis. Here we report that ceramide stimulates CREB3L1 cleavage by inverting the orientation of TM4SF20 in membranes. In the absence of ceramide, the N terminus of the first transmembrane helix of TM4SF20 is inserted into the endoplasmic reticulum (ER) lumen. This translocation requires TRAM2 (translocating chain-associated membrane protein 2), a membrane protein containing a putative ceramide-interacting domain. In the presence of ceramide, the N terminus of the first transmembrane domain of TM4SF20 is exposed to cytosol. Consequently, the membrane topology of TM4SF20 is inverted, and this form of TM4SF20 stimulates CREB3L1 cleavage. In the presence of ceramide, translocation of TM4SF20 is TRAM2-independent. We designate this mechanism-causing regulated inversion of the membrane topology as "regulated alternative translocation."
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Ceramidas/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Retículo Endoplasmático/metabolismo , Membranas Intracelulares/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Tetraspaninas/metabolismo , Células A549 , Sítios de Ligação , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/química , Humanos , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Proteínas de Membrana/metabolismo , Mutação , Proteínas do Tecido Nervoso/química , Ligação Proteica , Conformação Proteica em alfa-Hélice , Transporte Proteico , Proteólise , Interferência de RNA , Serina Endopeptidases/metabolismo , Relação Estrutura-Atividade , Tetraspaninas/química , Tetraspaninas/genética , Fatores de Tempo , TransfecçãoRESUMO
Ceramide is a lipid molecule that regulates diverse physiological and pathological reactions in part through inverting the topology of certain transmembrane proteins. This topological inversion is achieved through regulated alternative translocation (RAT), which reverses the direction by which membrane proteins are translocated across the endoplasmic reticulum during translation. However, owing to technical challenges in studying protein-ceramide interaction, it remains unclear how ceramide levels are sensed in cells to trigger RAT. Here, we report the synthesis of pac-C7-Cer, a photoactivatable and clickable short-chain ceramide analog that can be used as a probe to study protein-ceramide interactions. We demonstrate that translocating chain-associated membrane protein 2 (TRAM2), a protein known to control RAT of transmembrane 4 L6 subfamily member 20, and TRAM1, a homolog of TRAM2, interacted with molecules derived from pac-C7-Cer. This interaction was competed by naturally existing long-chain ceramide molecules. We showed that binding of ceramide and its analogs to TRAM2 correlated with their ability to induce RAT of transmembrane 4 L6 subfamily member 20. In addition to probing ceramide-TRAM interactions, we provide evidence that pac-C7-cer could be used for proteome-wide identification of ceramide-binding proteins. Our study provides mechanistic insights into RAT by identifying TRAMs as potential ceramide-binding proteins and establishes pac-C7-Cer as a valuable tool for future study of ceramide-protein interactions.
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Ceramidas/farmacologia , Glicoproteínas de Membrana/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Linhagem Celular Transformada , Ceramidas/química , Humanos , Masculino , Glicoproteínas de Membrana/química , Proteínas de Membrana Transportadoras/química , Ligação ProteicaRESUMO
A reduction in the synthesis of the neuromodulator histamine has been associated with Tourette's syndrome and obsessive-compulsive disorder. Symptoms of these disorders are thought to arise from a dysfunction or aberrant development ofcorticostriatal circuits. Here, we investigated how histamine affects developing corticostriatal circuits, both acutely and longer-term, during the first postnatal weeks, using patch-clamp and field recordings in mouse brain slices (C57Bl/6, male and female). Immunohistochemistry for histamine-containing axons reveals striatal histaminergic innervation by the second postnatal week, and qRT-PCR shows transcripts for H1, H2, and H3 histamine receptors in striatum from the first postnatal week onwards, with pronounced developmental increases in H3 receptor expression. Whole-cell patch-clamp recordings of striatal spiny projection neurons and histamine superfusion demonstrates expression of functional histamine receptors from the first postnatal week onwards, with histamine having diverse effects on their electrical properties, including depolarization of the membrane potential while simultaneously decreasing action potential output. Striatal field recordings and electrical stimulation of corticostriatal afferents revealed that histamine, acting at H3 receptors, negatively modulates corticostriatal synaptic transmission from the first postnatal week onwards. Last, we investigated effects of histamine on longer-term changes at developing corticostriatal synapses and show that histamine facilitates NMDA receptor-dependent LTP via H3 receptors during the second postnatal week, but inhibits synaptic plasticity at later developmental stages. Together, these results show that histamine acutely modulates developing striatal neurons and synapses and controls longer-term changes in developing corticostriatal circuits, thus providing insight into the possible etiology underlying neurodevelopmental disorders resulting from histamine dysregulation.SIGNIFICANCE STATEMENT Monogenic causes of neurologic disorders, although rare, can provide opportunities to both study and understand the brain. For example, a nonsense mutation in the coding gene for the histamine-synthesizing enzyme has been associated with Tourette's syndrome and obsessive-compulsive disorder, and dysfunction of corticostriatal circuits. Nevertheless, the etiology of these neurodevelopmental disorders and histamine's role in the development of corticostriatal circuits have remained understudied. Here we show that histamine is an active neuromodulator during the earliest periods of postnatal life and acts at developing striatal neurons and synapses. Crucially, we show that histamine permits NMDA receptor-dependent corticostriatal synaptic plasticity during an early critical period of postnatal development, which suggests that genetic or environmental perturbations of histamine levels can impact striatal development.
Assuntos
Córtex Cerebral/crescimento & desenvolvimento , Córtex Cerebral/fisiologia , Corpo Estriado/crescimento & desenvolvimento , Corpo Estriado/fisiologia , Histamina/fisiologia , Plasticidade Neuronal , Receptores Histamínicos/fisiologia , Animais , Corpo Estriado/efeitos dos fármacos , Feminino , Histamina/administração & dosagem , Masculino , Potenciais da Membrana , Camundongos Endogâmicos C57BL , Vias Neurais/crescimento & desenvolvimento , Vias Neurais/fisiologia , Receptores Histamínicos H1/fisiologia , Receptores Histamínicos H2/fisiologia , Receptores Histamínicos H3/fisiologia , Transmissão SinápticaRESUMO
[This corrects the article DOI: 10.2196/23272.].
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BACKGROUND: COVID-19, caused by SARS-CoV-2, has led to a global pandemic. The World Health Organization has also declared an infodemic (ie, a plethora of information regarding COVID-19 containing both false and accurate information circulated on the internet). Hence, it has become critical to test the veracity of information shared online and analyze the evolution of discussed topics among citizens related to the pandemic. OBJECTIVE: This research analyzes the public discourse on COVID-19. It characterizes risk communication patterns in four Asian countries with outbreaks at varying degrees of severity: South Korea, Iran, Vietnam, and India. METHODS: We collected tweets on COVID-19 from four Asian countries in the early phase of the disease outbreak from January to March 2020. The data set was collected by relevant keywords in each language, as suggested by locals. We present a method to automatically extract a time-topic cohesive relationship in an unsupervised fashion based on natural language processing. The extracted topics were evaluated qualitatively based on their semantic meanings. RESULTS: This research found that each government's official phases of the epidemic were not well aligned with the degree of public attention represented by the daily tweet counts. Inspired by the issue-attention cycle theory, the presented natural language processing model can identify meaningful transition phases in the discussed topics among citizens. The analysis revealed an inverse relationship between the tweet count and topic diversity. CONCLUSIONS: This paper compares similarities and differences of pandemic-related social media discourse in Asian countries. We observed multiple prominent peaks in the daily tweet counts across all countries, indicating multiple issue-attention cycles. Our analysis identified which topics the public concentrated on; some of these topics were related to misinformation and hate speech. These findings and the ability to quickly identify key topics can empower global efforts to fight against an infodemic during a pandemic.
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COVID-19/epidemiologia , Comunicação , Mídias Sociais/estatística & dados numéricos , COVID-19/virologia , Humanos , Pandemias , SARS-CoV-2/isolamento & purificaçãoRESUMO
BACKGROUND: Seipin is required for the correct assembly of cytoplasmic lipid droplets. In the absence of the yeast seipin homolog Sei1p (formerly Fld1p), droplets are slow to bud from the endoplasmic reticulum, lack the normal component of proteins on their surface, are highly heterogeneous in size and shape, often bud into the nucleus, and promote local proliferation of the endoplasmic reticulum in which they become tangled. But the mechanism by which seipin catalyzes lipid droplet formation is still uncertain. RESULTS: Seipin prevents a localized accumulation of phosphatidic acid (PA puncta) at ER-droplet junctions. PA puncta were detected with three different probes: Opi1p, Spo20p(51-91) and Pah1p. A system of droplet induction was used to show that PA puncta were not present until droplets were formed; the puncta appeared regardless of whether droplets consisted of triacylglycerol or steryl ester. Deletion strains were used to demonstrate that a single phosphatidic acid-producing enzyme is not responsible for the generation of the puncta, and the puncta remain resistant to overexpression of enzymes that metabolize phosphatidic acid, suggesting that this lipid is trapped in a latent compartment. Suppression of PA puncta requires the first 14 amino acids of Sei1p (Nterm), a domain that is also important for initiation of droplet assembly. Consistent with recent evidence that Ldb16p and Sei1p form a functional unit, the PA puncta phenotype in the ldb16Δ sei1Δ strain was rescued by human seipin. Moreover, PA puncta in the sei1Δ strain expressing Sei1p(ΔNterm) was suppressed by overexpression of Ldb16p, suggesting a functional interaction of Nterm with this protein. Overexpression of both Sei1p and Ldb16p, but not Sei1p alone, is sufficient to cause a large increase in droplet number. However, Ldb16p alone increases triacylglycerol accumulation in the ldb16Δ sei1Δ background. CONCLUSION: We hypothesize that seipin prevents formation of membranes with extreme curvature at endoplasmic reticulum/droplet junctions that would attract phosphatidic acid. While Ldb16p alone can affect triacylglycerol accumulation, proper droplet formation requires the collaboration of Sei1p and Ldb16.
Assuntos
Retículo Endoplasmático/metabolismo , Gotículas Lipídicas/metabolismo , Proteínas de Membrana/metabolismo , Proteínas Mitocondriais/metabolismo , Ácidos Fosfatídicos/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Triglicerídeos/metabolismo , Transporte Biológico , Retículo Endoplasmático/genética , Subunidades gama da Proteína de Ligação ao GTP/genética , Subunidades gama da Proteína de Ligação ao GTP/metabolismo , Humanos , Proteínas de Membrana/química , Proteínas de Membrana/genética , Proteínas Mitocondriais/genética , Estrutura Terciária de Proteína , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genéticaRESUMO
Lipin-1 catalyzes the formation of diacylglycerol from phosphatidic acid. Lipin-1 mutations cause lipodystrophy in mice and acute myopathy in humans. It is heavily phosphorylated, and the yeast ortholog Pah1p becomes membrane-associated and active upon dephosphorylation by the Nem1p-Spo7p membrane complex. A mammalian ortholog of Nem1p is the C-terminal domain nuclear envelope phosphatase 1 (CTDNEP1, formerly "dullard"), but its Spo7p-like partner is unknown, and the need for its existence is debated. Here, we identify the metazoan ortholog of Spo7p, TMEM188, renamed nuclear envelope phosphatase 1-regulatory subunit 1 (NEP1-R1). CTDNEP1 and NEP1-R1 together complement a nem1Δspo7Δ strain to block endoplasmic reticulum proliferation and restore triacylglycerol levels and lipid droplet number. The two human orthologs are in a complex in cells, and the amount of CTDNEP1 is increased in the presence of NEP1-R1. In the Caenorhabditis elegans embryo, expression of nematode CTDNEP1 and NEP1-R1, as well as lipin-1, is required for normal nuclear membrane breakdown after zygote formation. The expression pattern of NEP1-R1 and CTDNEP1 in human and mouse tissues closely mirrors that of lipin-1. CTDNEP1 can dephosphorylate lipins-1a, -1b, and -2 in human cells only in the presence of NEP1-R1. The nuclear fraction of lipin-1b is increased when CTDNEP1 and NEP1-R1 are co-expressed. Therefore, NEP1-R1 is functionally conserved from yeast to humans and functions in the lipin activation pathway.
Assuntos
Proteínas de Membrana/metabolismo , Proteínas Nucleares/metabolismo , Fosfatidato Fosfatase/metabolismo , Proteína Fosfatase 1/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Linhagem Celular , Humanos , Proteínas de Membrana/genética , Camundongos , Membrana Nuclear/enzimologia , Membrana Nuclear/genética , Proteínas Nucleares/genética , Fosfatidato Fosfatase/genética , Proteína Fosfatase 1/genética , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Homologia de Sequência de AminoácidosRESUMO
Metal pollutants are a global health risk due to their ability to contribute to a variety of diseases. Aluminum (Al), a ubiquitous environmental contaminant is implicated in anemia, osteomalacia, hepatic disorder, and neurological disorder. In this review, we outline how this intracellular generator of reactive oxygen species (ROS) triggers a metabolic shift towards lipogenesis in astrocytes and hepatocytes. This Al-evoked phenomenon is coupled to diminished mitochondrial activity, anerobiosis, and the channeling of α-ketoacids towards anti-oxidant defense. The resulting metabolic reconfiguration leads to fat accumulation and a reduction in ATP synthesis, characteristics that are common to numerous medical disorders. Hence, the ability of Al toxicity to create an oxidative environment promotes dysfunctional metabolic processes in astrocytes and hepatocytes. These molecular events triggered by Al-induced ROS production are the potential mediators of brain and liver disorders.
Assuntos
Alumínio/toxicidade , Doença Hepática Induzida por Substâncias e Drogas , Doenças do Sistema Nervoso/induzido quimicamente , Espécies Reativas de Oxigênio/metabolismo , Alumínio/química , Alumínio/metabolismo , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Dislipidemias/induzido quimicamente , Exposição Ambiental , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Humanos , Metabolismo dos Lipídeos , Lipogênese/efeitos dos fármacos , Hepatopatias , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Doenças Mitocondriais/induzido quimicamente , Estresse Oxidativo/efeitos dos fármacosRESUMO
Gel electrophoresis is routinely used to separate and analyse macromolecules in biological systems. Although many of these electrophoretic techniques necessitate the denaturing of the analytes prior to their analysis, blue native polyacrylamide gel electrophoresis (BN-PAGE) permits the investigation of proteins/enzymes and their supramolecular structures such as the metabolon in native form. This attribute renders this analytical tool conducive to deciphering the metabolic perturbations invoked by metal toxicity. In this review, we elaborate on how BN-PAGE has led to the discovery of the dysfunctional metabolic pathways associated with disorders such as Alzheimer's disease, Parkinson's disease, and obesity that have been observed as a consequence of exposure to various metal toxicants.
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Doença de Alzheimer/metabolismo , Metais Pesados/toxicidade , Eletroforese em Gel de Poliacrilamida Nativa/métodos , Obesidade/metabolismo , Doença de Parkinson/metabolismo , Doença de Alzheimer/patologia , Ciclo do Ácido Cítrico/efeitos dos fármacos , Eletroforese em Gel Bidimensional , Glicólise/efeitos dos fármacos , Humanos , Obesidade/patologia , Estresse Oxidativo/efeitos dos fármacos , Oxirredutases/química , Oxirredutases/metabolismo , Doença de Parkinson/patologia , Ligação Proteica/efeitos dos fármacos , Conformação Proteica/efeitos dos fármacos , Corantes de Rosanilina , Análise de Sequência de ProteínaRESUMO
Transmembrane proteins must adopt proper topology to perform their functions. We previously demonstrated that ceramide regulates TM4SF20 (transmembrane 4 L6 family 20) by altering the topology of the transmembrane protein, but the underlying mechanism remains obscure. Here we report that TM4SF20 is synthesized in the endoplasmic reticulum (ER) with a cytosolic C terminus and a luminal loop before the last transmembrane helix where N132, N148, and N163 are glycosylated. In the absence of ceramide, the sequence surrounding glycosylated N163 but not N132 is retrotranslocated from lumen to cytosol independent of ER-associated degradation. Accompanying this retrotranslocation, the C terminus of the protein is relocated from cytosol to lumen. Ceramide delays the retrotranslocation process, causing accumulation of the protein that is originally synthesized. Our findings suggest that N-linked glycans, although synthesized in the lumens, may be exposed to cytosol through retrotranslocation, a reaction that may play a crucial role in topological regulation of transmembrane proteins.
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Retículo Endoplasmático , Proteínas de Membrana , Citosol/metabolismo , Proteínas de Membrana/metabolismo , Retículo Endoplasmático/metabolismo , Degradação Associada com o Retículo Endoplasmático , Ceramidas/metabolismoRESUMO
Machine learning approaches using satellite imagery are providing accessible ways to infer socioeconomic measures without visiting a region. However, many algorithms require integration of ground-truth data, while regional data are scarce or even absent in many countries. Here we present our human-machine collaborative model which predicts grid-level economic development using publicly available satellite imagery and lightweight subjective ranking annotation without any ground data. We applied the model to North Korea and produced fine-grained predictions of economic development for the nation where data is not readily available. Our model suggests substantial development in the country's capital and areas with state-led development projects in recent years. We showed the broad applicability of our model by examining five of the least developed countries in Asia, covering 400,000 grids. Our method can both yield highly granular economic information on hard-to-visit and low-resource regions and can potentially guide sustainable development programs.
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Phosphoenolpyruvate (PEP)-dependent kinases are central to numerous metabolic processes and mediate the production of adenosine triphosphate (ATP) by substrate-level phosphorylation (SLP). While pyruvate kinase (PK, EC: 2.7.1.40), the final enzyme of the glycolytic pathway is critical in the anaerobic synthesis of ATP from ADP, pyruvate phosphate dikinase (PPDK, EC: 2.7.9.1), and phosphoenolpyruvate synthase (PEPS, EC: 2.7.9.2) help generate ATP from AMP coupled to PEP as a substrate. Here we demonstrate an inexpensive and effective electrophoretic technology to determine the activities of these enzymes by blue-native polyacrylamide gel electrophoresis (BN-PAGE). The generation of pyruvate is linked to exogenous lactate dehydrogenase (LDH), and the oxidation of reduced nicotinamide adenine dinucleotide (NADH) coupled to 2,6-dichloroindophenol (DCIP) and iodonitrotetrazolium chloride (INT) results in a formazan precipitate which is easily quantifiable. The selectivity of the enzymes is ensured by including either AMP or ADP and pyrophosphate (PP(i) ) or inorganic phosphate (P(i) ). Activity bands were readily obtained after incubation in the respective reaction mixtures for 20-30 min. Cell-free extract concentrations as low as 20 µg protein equivalent yielded activity bands and substrate levels were manipulated to optimize sensitivity of this analytical technique. High-pressure liquid chromatography (HPLC), two-dimensional (2-D) SDS-PAGE (where SDS is sodium dodecyl sulfate), and immunoblot studies of the excised activity band help further characterize these PEP-dependent kinases. Furthermore, these enzymes were readily identified on the same gel by incubating it sequentially in the respective reaction mixtures. This technique provides a facile method to elucidate these kinases in biological systems.
Assuntos
Eletroforese em Gel de Poliacrilamida/métodos , Fosfotransferases (Aceptores Pareados)/metabolismo , Piruvato Ortofosfato Diquinase/metabolismo , Ácido Pirúvico/metabolismo , Trifosfato de Adenosina/química , Trifosfato de Adenosina/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Sistema Livre de Células , Cromatografia Líquida de Alta Pressão , Eletroforese em Gel Bidimensional , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Immunoblotting , L-Lactato Desidrogenase/química , L-Lactato Desidrogenase/metabolismo , Fosfotransferases (Aceptores Pareados)/química , Pseudomonas fluorescens/enzimologia , Piruvato Quinase/química , Piruvato Quinase/metabolismo , Piruvato Ortofosfato Diquinase/química , Ácido Pirúvico/químicaRESUMO
Preeclampsia (PE) is a major disease of pregnancy, with various short- or long-term complications for both the mother and offspring. We focused on the body mass index (BMI) of offspring and compared the incidence of obesity during early childhood between PE- and non-PE-affected pregnancies. Women with singleton births (n = 1,697,432) were identified from the Korea National Health Insurance database. The outcomes of offspring at 30-80 months of age were analyzed. The effects of PE on BMI and the incidence of obesity in the offspring were compared. The incidence of low birth weight (LBW) offspring was higher in the PE group (n = 29,710) than that in the non-PE group (n = 1,533,916) (24.70% vs. 3.33%, p < 0.01). However, BMI was significantly higher in the PE-affected offspring than that in non-PE-affected offspring. After adjusting for various factors, the risk of obesity was higher in the PE-affected offspring (odds ratio = 1.34, 95% confidence interval = 1.30-1.38). The BMI and incidence of obesity were higher during early childhood in the PE-affected offspring, even though the proportion of LBW was higher. These results may support the basic hypotheses for the occurrence of various cardiovascular and metabolic complications in PE-affected offspring. In addition, early-age incidence of obesity could influence PE management and child consultation in clinical applications.
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BACKGROUND: As societies become more complex, larger populations suffer from insomnia. In 2014, the US Centers for Disease Control and Prevention declared that sleep disorders should be dealt with as a public health epidemic. However, it is hard to provide adequate treatment for each insomnia sufferer, since various behavioral characteristics influence symptoms of insomnia collectively. OBJECTIVE: We aim to develop a neural-net based unsupervised user clustering method towards insomnia sufferers in order to clarify the unique traits for each derived groups. Unlike the current diagnosis of insomnia that requires qualitative analysis from interview results, the classification of individuals with insomnia by using various information modalities from smart bands and neural-nets can provide better insight into insomnia treatments. METHODS: This study, as part of the precision psychiatry initiative, is based on a smart band experiment conducted over 6 weeks on individuals with insomnia. During the experiment period, a total of 42 participants (19 male; average age 22.00 [SD 2.79]) from a large university wore smart bands 24/7, and 3 modalities were collected and examined: sleep patterns, daily activities, and personal demographics. We considered the consecutive daily information as a form of images, learned the latent variables of the images via a convolutional autoencoder (CAE), and clustered and labeled the input images based on the derived features. We then converted consecutive daily information into a sequence of the labels for each subject and finally clustered the people with insomnia based on their predominant labels. RESULTS: Our method identified 5 new insomnia-activity clusters of participants that conventional methods have not recognized, and significant differences in sleep and behavioral characteristics were shown among groups (analysis of variance on rank: F4,37=2.36, P=.07 for the sleep_min feature; F4,37=9.05, P<.001 for sleep_efficiency; F4,37=8.16, P<.001 for active_calorie; F4,37=6.53, P<.001 for walks; and F4,37=3.51, P=.02 for stairs). Analyzing the consecutive data through a CAE and clustering could reveal intricate connections between insomnia and various everyday activity markers. CONCLUSIONS: Our research suggests that unsupervised learning allows health practitioners to devise precise and tailored interventions at the level of data-guided user clusters (ie, precision psychiatry), which could be a novel solution to treating insomnia and other mental disorders.
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Medicina de Precisão/métodos , Distúrbios do Início e da Manutenção do Sono/fisiopatologia , Sono/fisiologia , Dispositivos Eletrônicos Vestíveis/efeitos adversos , Algoritmos , Índice de Massa Corporal , Análise por Conglomerados , Estudos de Avaliação como Assunto , Feminino , Humanos , Masculino , Psiquiatria/instrumentação , Distúrbios do Início e da Manutenção do Sono/diagnóstico , Distúrbios do Início e da Manutenção do Sono/epidemiologia , Distúrbios do Início e da Manutenção do Sono/psicologia , Aprendizado de Máquina não Supervisionado/economia , Adulto JovemRESUMO
G protein-coupled receptors (GPCRs) are a family of proteins containing seven transmembrane helices, with the N- and C-terminus of the protein located at the extracellular space and cytosol, respectively. Here, we report that ceramide or related sphingolipids might invert the topology of many GPCRs that contain a GXXXN motif in their first transmembrane helix. The functional significance of this topological regulation is illustrated by the CCR5 chemokine receptor. In the absence of lipopolysaccharide (LPS), CCR5 adopts a topology consistent with that of GPCR, allowing mouse peritoneal macrophages to migrate toward its ligand CCL5. LPS stimulation results in increased production of dihydroceramide, which inverts the topology of CCR5, preventing macrophages from migrating toward CCL5. These results suggest that GPCRs may not always adopt the same topology and can be regulated through topological inversion. Editorial note: This article has been through an editorial process in which the authors decide how to respond to the issues raised during peer review. The Reviewing Editor's assessment is that major issues remain unresolved (see decision letter).
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Ceramidas/metabolismo , Receptores CCR5/química , Receptores CCR5/metabolismo , Receptores Acoplados a Proteínas G/química , Receptores Acoplados a Proteínas G/metabolismo , Regulação Alostérica , Animais , Movimento Celular , Células Cultivadas , Lipopolissacarídeos/metabolismo , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/fisiologia , Camundongos Endogâmicos C57BL , Conformação ProteicaRESUMO
Clear cell renal cell carcinoma (ccRCC), which accounts for the majority of kidney cancer, is known to accumulate excess cholesterol. However, the mechanism and functional significance of the lipid accumulation for development of the cancer remains obscure. In this study, we analyzed 42 primary ccRCC samples, and determined that cholesterol levels of ~ 70% of the tumors were at least two-fold higher than that of benign kidney tissues. Compared to tumors without cholesterol accumulation, those containing excess cholesterol expressed higher levels of scavenger receptor BI (SR-B1), a receptor for uptake of HDL-associated cholesterol, but not genes involved in cholesterol synthesis and uptake of LDL-associated cholesterol. To further determine the roles of sterol accumulation for cancer development, we implanted ccRCC from patients into mouse kidneys using a mouse ccRCC xenograft model. Feeding mice with probucol, a compound lowing HDL-cholesterol, markedly reduced levels of cholesterol in tumors containing excess cholesterol. This treatment, however, did not affect growth of these tumors. Our study suggests that cholesterol overaccumulation in ccRCC is the consequence of increased uptake of HDL-cholesterol as a result of SR-B1 overexpression, but the lipid accumulation by itself may not play a significant role in progression of the cancer.
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Carcinoma de Células Renais/metabolismo , HDL-Colesterol/metabolismo , Neoplasias Renais/metabolismo , Animais , Transporte Biológico , Carcinoma de Células Renais/patologia , Humanos , Rim/metabolismo , Rim/patologia , Neoplasias Renais/patologia , Metabolismo dos Lipídeos , Lipidômica , Masculino , Camundongos Endogâmicos NOD , Camundongos SCIDRESUMO
Up to date, many biological pathways related to cancer have been extensively applied thanks to outputs of burgeoning biomedical research. This leads to a new technical challenge of exploring and validating biological pathways that can characterize transcriptomic mechanisms across different disease subtypes. In pursuit of accommodating multiple studies, the joint Gaussian graphical model was previously proposed to incorporate nonzero edge effects. However, this model is inevitably dependent on post hoc analysis in order to confirm biological significance. To circumvent this drawback, we attempt not only to combine transcriptomic data but also to embed pathway information, well-ascertained biological evidence as such, into the model. To this end, we propose a novel statistical framework for fitting joint Gaussian graphical model simultaneously with informative pathways consistently expressed across multiple studies. In theory, structured nodes can be prespecified with multiple genes. The optimization rule employs the structured input-output lasso model, in order to estimate a sparse precision matrix constructed by simultaneous effects of multiple studies and structured nodes. With an application to breast cancer data sets, we found that the proposed model is superior in efficiently capturing structures of biological evidence (e.g., pathways). An R software package nsiGGM is publicly available at author's webpage.
Assuntos
Modelos Biológicos , Transcriptoma , Neoplasias da Mama/diagnóstico , Humanos , Distribuição NormalRESUMO
Recent research in the field of gecko-inspired dry adhesive has focused on modifying the material and structural properties of polymer-based nanohairs. Polymers such as polystyrene (PS), high-density polyethylene (HDPE), ultraviolet curable epoxy (SU-8), polyurethane acrylate (PUA), polycarbonate (PC), and polydimethyl siloxane (PDMS) can fulfill many mechanical property requirements, are easily tunable, and can be produced via large-scale fabrication. However, the fabrication process for tilted structure remains challenging. The tilted structure is a crucial factor in high-degree conformal contact, which facilitates high adhesion, low effective modulus, and directional adhesion properties. Recent studies have attempted to create a tilted structure by applying beam irradiation, mechanical and thermal stress, and magnetic fields. This review provides a comprehensive investigation into advanced strategies for producing tilted polymeric nanostructures and their potential applications in the near future.