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The neurodevelopmental disorders Prader-Willi syndrome (PWS) and Schaaf-Yang syndrome (SYS) both arise from genomic alterations within human chromosome 15q11-q13. A deletion of the SNORD116 cluster, encoding small nucleolar RNAs, or frameshift mutations within MAGEL2 result in closely related phenotypes in individuals with PWS or SYS, respectively. By investigation of their subcellular localization, we observed that in contrast to a predominant cytoplasmic localization of wild-type (WT) MAGEL2, a truncated MAGEL2 mutant was evenly distributed between the cytoplasm and the nucleus. To elucidate regulatory pathways that may underlie both diseases, we identified protein interaction partners for WT or mutant MAGEL2, in particular the survival motor neuron protein (SMN), involved in spinal muscular atrophy, and the fragile-X-messenger ribonucleoprotein (FMRP), involved in autism spectrum disorders. The interactome of the non-coding RNA SNORD116 was also investigated by RNA-CoIP. We show that WT and truncated MAGEL2 were both involved in RNA metabolism, while regulation of transcription was mainly observed for WT MAGEL2. Hence, we investigated the influence of MAGEL2 mutations on the expression of genes from the PWS locus, including the SNORD116 cluster. Thereby, we provide evidence for MAGEL2 mutants decreasing the expression of SNORD116, SNORD115, and SNORD109A, as well as protein-coding genes MKRN3 and SNRPN, thus bridging the gap between PWS and SYS.
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Peptídeos e Proteínas de Sinalização Intracelular , Proteínas Intrinsicamente Desordenadas , Síndrome de Prader-Willi , Humanos , Cromossomos Humanos Par 15/genética , Citoplasma/metabolismo , Células HEK293 , Mutação , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Síndrome de Prader-Willi/genética , Proteínas/genética , Proteínas/metabolismo , RNA Nucleolar Pequeno/genéticaRESUMO
Sustainability is a core topic for all sectors including geotechnical engineering (e.g., design of foundations, earthworks structures, and pavements for major infrastructure and building projects). Despite being comprised of environmental, economic, and social pillars, most sustainability studies in this area have focused on the first. Furthermore, social impacts and the three pillars integration are little explored. As a result, there is a lack of systemic and holistic assessments of innovative geotechnical alternatives. This research advances in this area by performing a complete sustainability assessment and integration of the environmental, economic, and social pillars of two expansive soil stabilization alternatives: (i) sugar cane bagasse ash combined with hydrated eggshell lime alkali-activated by sodium hydroxide (NaOH) and (ii) Portland cement. Individual analyses were carried out to determine the environmental, economic, and social impacts, and the single sustainability index. Alkali-activated binder dosages showed higher impacts in 4 out of 10 environmental categories. For both binders, high-density/low-binder dosages contributed to environmental and economic sustainability as they require lower quantities of raw materials and diesel for materials transportation. The total costs of alkali-activated binder dosages ($189.79 and $154.45) were higher than that of Portland cement ($72.49 and $54.04), mainly due to the high cost of NaOH acquisition. However, the alkali-activated binder dosages implied lower carbon dioxide (CO2) emissions and thus lower social cost of CO2. The alternative binder presented a higher positive social impact. The alkali-activated high-density/low binder dosage is the most sustainable soil stabilization strategy.
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Celulose , Saccharum , Solo , Animais , Solo/química , Mudança Social , Dióxido de Carbono , Casca de Ovo , Hidróxido de Sódio , ÁlcalisRESUMO
This work presents a neurorobotics model of the brain that integrates the cerebellum and the basal ganglia regions to coordinate movements in a humanoid robot. This cerebellar-basal ganglia circuitry is well known for its relevance to the motor control used by most mammals. Other computational models have been designed for similar applications in the robotics field. However, most of them completely ignore the interplay between neurons from the basal ganglia and cerebellum. Recently, neuroscientists indicated that neurons from both regions communicate not only at the level of the cerebral cortex but also at the subcortical level. In this work, we built an integrated neurorobotics model to assess the capacity of the network to predict and adjust the motion of the hands of a robot in real time. Our model was capable of performing different movements in a humanoid robot by respecting the sensorimotor loop of the robot and the biophysical features of the neuronal circuitry. The experiments were executed in simulation and the real world. We believe that our proposed neurorobotics model can be an important tool for new studies on the brain and a reference toward new robot motor controllers.
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Gânglios da Base , Cerebelo , Animais , Cerebelo/fisiologia , Movimento/fisiologia , Córtex Cerebral/fisiologia , Neurônios , MamíferosRESUMO
Waste stabilization processes are important to add value and reduce environmental risks related to metal contamination of soils and groundwater. This study evaluated the metal encapsulation of: (i) waste foundry sand (WFS) stabilized with an alkali-activated binder (AAB), compared to (ii) WFS-Portland cement (PC) mixture. The AAB was composed by sugar cane bagasse ash (SCBA), hydrated eggshell lime, and sodium hydroxide solution. The metal leaching behavior from WFS-AAB and WFS-PC was investigated through batch and column tests according to NBR 10005 and ASTM D4874 methods, respectively. All WFS-AAB and WFS-PC mixtures showed no metal toxicity. WFS-AAB matrices encapsulated the heavy metals Cd, Cr, and Pb from WFS and SCBA. Leaching results from NBR 10005 method were more favorable than ASTM D4874 for water quality limits (CONAMA 460, Dutch List, and EPA). Binder type, metals leaching patterns, and leaching test procedures were key factors in understanding the environmental performance of cemented WFS.
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Metais Pesados , Areia , Álcalis , Metais Pesados/análise , Solo , Cinza de CarvãoRESUMO
Heterozygous mutations in the gene encoding RagD GTPase were shown to cause a novel autosomal dominant condition characterized by kidney tubulopathy and cardiomyopathy. We previously demonstrated that RagD, and its paralogue RagC, mediate a non-canonical mTORC1 signaling pathway that inhibits the activity of TFEB and TFE3, transcription factors of the MiT/TFE family and master regulators of lysosomal biogenesis and autophagy. Here we show that RagD mutations causing kidney tubulopathy and cardiomyopathy are "auto- activating", even in the absence of Folliculin, the GAP responsible for RagC/D activation, and cause constitutive phosphorylation of TFEB and TFE3 by mTORC1, without affecting the phosphorylation of "canonical" mTORC1 substrates, such as S6K. By using HeLa and HK-2 cell lines, human induced pluripotent stem cell-derived cardiomyocytes and patient-derived primary fibroblasts, we show that RRAGD auto-activating mutations lead to inhibition of TFEB and TFE3 nuclear translocation and transcriptional activity, which impairs the response to lysosomal and mitochondrial injury. These data suggest that inhibition of MiT/TFE factors plays a key role in kidney tubulopathy and cardiomyopathy syndrome.
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Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos , Células-Tronco Pluripotentes Induzidas , Humanos , Autofagia/genética , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Células HeLa , Células-Tronco Pluripotentes Induzidas/metabolismo , Rim/metabolismo , Lisossomos/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , MutaçãoRESUMO
The transcription factor TFEB is a master regulator of lysosomal biogenesis and autophagy1. The phosphorylation of TFEB by the mechanistic target of rapamycin complex 1 (mTORC1)2-5 is unique in its mTORC1 substrate recruitment mechanism, which is strictly dependent on the amino acid-mediated activation of the RagC GTPase activating protein FLCN6,7. TFEB lacks the TOR signalling motif responsible for the recruitment of other mTORC1 substrates. We used cryogenic-electron microscopy to determine the structure of TFEB as presented to mTORC1 for phosphorylation, which we refer to as the 'megacomplex'. Two full Rag-Ragulator complexes present each molecule of TFEB to the mTOR active site. One Rag-Ragulator complex is bound to Raptor in the canonical mode seen previously in the absence of TFEB. A second Rag-Ragulator complex (non-canonical) docks onto the first through a RagC GDP-dependent contact with the second Ragulator complex. The non-canonical Rag dimer binds the first helix of TFEB with a RagCGDP-dependent aspartate clamp in the cleft between the Rag G domains. In cellulo mutation of the clamp drives TFEB constitutively into the nucleus while having no effect on mTORC1 localization. The remainder of the 108-amino acid TFEB docking domain winds around Raptor and then back to RagA. The double use of RagC GDP contacts in both Rag dimers explains the strong dependence of TFEB phosphorylation on FLCN and the RagC GDP state.
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Lisossomos , Alvo Mecanístico do Complexo 1 de Rapamicina , Proteínas Monoméricas de Ligação ao GTP , Aminoácidos/metabolismo , Domínio Catalítico , Guanosina Difosfato/metabolismo , Lisossomos/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Fosforilação , Multimerização Proteica , Proteína Regulatória Associada a mTOR/metabolismo , Transdução de SinaisRESUMO
Target-of-rapamycin complex 1 resides on lysosomes/vacuoles and additionally on signaling endosomes. Gao et al. (2022. J. Cell Biol.https://doi.org/10.1083/jcb.202109084) set out to define the molecular identity of signaling endosomes, along with players required for the formation and maintenance of this endosomal subpopulation.
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Endossomos , Alvo Mecanístico do Complexo 1 de Rapamicina , Proteínas de Saccharomyces cerevisiae , Transdução de Sinais , Fatores de Transcrição , Vacúolos , Lisossomos , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Saccharomyces cerevisiaeRESUMO
Cysticercosis is a parasitic infection that is caused by the tapeworm Taenia solium and is prevalent in Latin America, southern Africa, and parts of Asia. Cysticercosis normally affects the central nervous system, but rare cases of cardiac cysticercosis have been reported in the literature. We report a case of asymptomatic cardiac cysticercosis in a 54-year-old Afro-Brazilian man with a history of hemicolectomy and chemotherapy, who demonstrated characteristic intramyocardial lesions on transthoracic echocardiogram and cardiac magnetic resonance imaging, and responded well to subsequent treatment with albendazole and prednisone.
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BACKGROUND: Little is known about peripherally inserted central catheter (PICC) use, appropriateness and device outcomes in Brazil. METHODS: We conducted an observational, prospective, cohort study spanning 16 Brazilian hospitals from October 2018 to August 2020. Patients ≥18 years receiving a PICC were included. PICC placement variables were abstracted from medical records. PICC-related major (deep vein thrombosis (DVT), central line-associated bloodstream infection (CLABSI) and catheter occlusion) and minor complications were collected. Appropriateness was evaluated using the Michigan Appropriateness Guide for Intravenous Catheters (MAGIC). Devices were considered inappropriate if they were in place for <5 days, were multi-lumen, and/or were placed in patients with a creatinine >2.0 mg/dL. PICCs considered appropriate met none of these criteria. Mixed-effects logistic regression models adjusting for patient-level and hospital-level characteristics assessed the association between appropriateness and major complications. RESULTS: Data from 12 725 PICCs were included. Mean patient age was 66.4±19 years and 51.0% were female. The most common indications for PICCs were intravenous antibiotics (81.1%) and difficult access (62.7%). Most PICCs (72.2%) were placed under ultrasound guidance. The prevalence of complications was low: CLABSI (0.9%); catheter-related DVT (1.0%) and reversible occlusion (2.5%). Of the 12 725 devices included, a total of 7935 (62.3%) PICCs were inappropriate according to MAGIC. With respect to individual metrics for appropriateness, 17.0% were placed for <5 days, 60.8% were multi-lumen and 11.3% were in patients with creatinine >2.0 mg/dL. After adjusting for patient and hospital-level characteristics, multi-lumen PICCs considered inappropriate were associated with greater odds of major complications (OR 2.54, 95% CI 1.61 to 4.02). CONCLUSIONS: Use of PICCs in Brazilian hospitals appears to be safe and comparable with North America. However, opportunities to improve appropriateness remain. Future studies examining barriers and facilitators to improving device use in Brazil would be welcomed.
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Infecções Relacionadas a Cateter , Cateterismo Venoso Central , Cateterismo Periférico , Cateteres Venosos Centrais , Idoso , Idoso de 80 Anos ou mais , Brasil/epidemiologia , Infecções Relacionadas a Cateter/epidemiologia , Cateterismo Venoso Central/métodos , Cateterismo Periférico/efeitos adversos , Catéteres , Cateteres Venosos Centrais/efeitos adversos , Estudos de Coortes , Creatinina , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Estudos Retrospectivos , Fatores de RiscoRESUMO
BACKGROUND: A key factor for the success and longevity of the endodontic treatment is sealing of the cavity after restorative treatment. AIM: The aim of this randomised clinical trial was to evaluate the 1-year survival of endodontic treatment in primary molars restored with stainless steel crowns (SSCs) and bulk fill composite resin (BF). As a secondary outcome, the acceptance of both children and parents was evaluated. DESIGN: Ninety-one 3- to 8-year-old children with at least one primary molar requiring endodontic treatment were selected. Participants were randomized to SSC or BF and evaluated after 1, 3, 6, and 12 months. An acceptance questionnaire was completed immediately after the treatment. The primary outcome was the endodontic treatment success, evaluated in the intention-to-treat (ITT) population using the Kaplan-Meier and non-inferiority Cox regression analyses, with a non-inferiority limit of 15%. Sensitivity analysis between the success rates after 1 year was performed using Miettinen-Nurminen's method. The Mann-Whitney test was used to compare the treatment acceptance (α = 5%). RESULTS: The survival rate after 1 year was BF = 75% and SSC = 88% (HR = 1.41; 90% CI 0.57-3.43). ITT analysis showed a success rate of BF = 86.7% and SSC = 82.6% (RR = 0.95; 0.78-1.16). The non-inferiority hypothesis between the survival of endodontic treatment could not be proved in both analyses (P > .05). The overall acceptance scores did not differ between the restorative groups (P > .05). CONCLUSION: This study failed to show non-inferiority of BF compared with the SSC. The materials were well accepted by both children and their parents.
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Pulpectomia , Aço Inoxidável , Criança , Pré-Escolar , Coroas , Humanos , Dente Molar/cirurgia , PaisRESUMO
Este estudo analisa a percepção de enfermeiros e gerentes da APS acerca da percepção de enfermeiros e gerentes da Atenção Primária à Saúde (APS) no que se refere aos mecanismos da participação popular. Trata-se de um estudo descritivo-exploratório de abordagem qualitativa, cujos participantes foram enfermeiros e gerentes da Estratégia Saúde da Família de um município no interior do Estado do Ceará. A coleta de dados foi realizada por meio de entrevista semiestruturada e teve a análise feita por meio da técnica de Análise de Conteúdo de Bardin com suporte do software N VIVO 11. O estudo respeitou os princípios éticos referentes à Resolução 466/2012 do CNS. O estudo revela a adoção de diferentes estratégias pelos profissionais para fomentar o protagonismo dos usuários no controle social. Entretanto, apesar disso, ainda pode-se perceber a resistência dos indivíduos a exercerem seus direitos de cidadania. Assim, cabe aos profissionais incentivar o comportamento participativo dos usuários.
This study analyzes the perception of nurses and PHC managers about the articulation of the health service with the community. This is a descriptive-exploratory study with a qualitative approach, whose participants were nurses and managers of the Family Health Strategy of a municipality in the countryside of the State of Ceará. Data collection was carried out through semi-structured interviews and the analysis was carried out using the Bardin Content Analysis technique, supported by the N VIVO 11 software. The study respected the ethical principles related to CNS Resolution 466/2012 . The study reveals the adoption of different strategies by professionals to foster the role of users in social control. However, despite this, it is still possible to perceive the resistance of individuals to exercise their citizenship rights. Thus, it is up to professionals to strengthen the politicized bases of users.
Assuntos
Atenção Primária à Saúde , Participação da ComunidadeRESUMO
Seizure threshold 2 (SZT2) is a component of the KICSTOR complex which, under catabolic conditions, functions as a negative regulator in the amino acid-sensing branch of mTORC1. Mutations in this gene cause a severe neurodevelopmental and epileptic encephalopathy whose main symptoms include epilepsy, intellectual disability, and macrocephaly. As SZT2 remains one of the least characterized regulators of mTORC1, in this work we performed a systematic interactome analysis under catabolic and anabolic conditions. Besides numerous mTORC1 and AMPK signaling components, we identified clusters of proteins related to autophagy, ciliogenesis regulation, neurogenesis, and neurodegenerative processes. Moreover, analysis of SZT2 ablated cells revealed increased mTORC1 signaling activation that could be reversed by Rapamycin or Torin treatments. Strikingly, SZT2 KO cells also exhibited higher levels of autophagic components, independent of the physiological conditions tested. These results are consistent with our interactome data, in which we detected an enriched pool of selective autophagy receptors/regulators. Moreover, preliminary analyses indicated that SZT2 alters ciliogenesis. Overall, the data presented form the basis to comprehensively investigate the physiological functions of SZT2 that could explain major molecular events in the pathophysiology of developmental and epileptic encephalopathy in patients with SZT2 mutations.
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Complexos Multiproteicos/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Mapas de Interação de Proteínas , Aminoácidos/deficiência , Animais , Proteínas Sanguíneas/farmacologia , Cílios/efeitos dos fármacos , Cílios/metabolismo , Cães , Células HEK293 , Humanos , Células Madin Darby de Rim Canino , Alvo Mecanístico do Complexo 1 de Rapamicina/antagonistas & inibidores , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Organogênese/efeitos dos fármacos , Análise de Componente Principal , Mapas de Interação de Proteínas/efeitos dos fármacos , Sirolimo/farmacologiaRESUMO
BACKGROUND: Dental caries in adolescents remains a significant public health problem with few oral health promotion interventions aimed at reducing dental caries in secondary school-aged students. Previous oral health and mobile health (mHealth) research has suggested the need for the development of a school-based behaviour change intervention incorporating a digital component. This study aimed to describe the development process of a behaviour change intervention to improve the oral health of students aged 11-16 years attending secondary schools in the UK. METHODS: A six-step process was used to develop the complex intervention informed by behaviour change theory and involving students, young people, parents and teachers in the process. The steps were: (1) identifying the target behaviours, namely tooth brushing with a fluoride toothpaste (2) identifying the theoretical basis and developing the causal model (3) reviewing the relevant literature and developing the logic model (4) designing the intervention with young people, parents and school staff (5) specifying the intervention content and (6) translating this content into features of the intervention and piloting. RESULTS: The resultant intervention included a quality-assured classroom-based session (CBS) (guided by a lesson plan and teaching resources), delivered by school teachers which was embedded within the school curriculum. This CBS was followed by a series of (Short Message Service) SMS texts delivered twice daily to student's mobile telephones with the content, duration and timing of the messages informed by involvement of students and young people. CONCLUSIONS: An intervention to improve the oral health of secondary school students through improved tooth brushing was rigorously developed based on behaviour change theory and work with young people, parents and school staff. Further research is needed to evaluate the outcomes and processes involved following the delivery of this intervention. BRIGHT Trial Trial Registration ISRCTN12139369.
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Cárie Dentária , Escovação Dentária , Adolescente , Criança , Cárie Dentária/prevenção & controle , Comportamentos Relacionados com a Saúde , Humanos , Pais , Instituições AcadêmicasRESUMO
In this work, we present the first steps toward the creation of a new neurorobotics model of Parkinson's Disease (PD) that embeds, for the first time in a real robot, a well-established computational model of PD. PD mostly affects the modulation of movement in humans. The number of people suffering from this neurodegenerative disease is set to double in the next 15 years and there is still no cure. With the new model we were capable to further explore the dynamics of the disease using a humanoid robot. Results show that the embedded model under both conditions, healthy and parkinsonian, was capable of performing a simple behavioural task with different levels of motor disturbance. We believe that this neurorobotics model is a stepping stone to the development of more sophisticated models that could eventually test and inform new PD therapies and help to reduce and replace animals in research.
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The anterior cingulate cortex (ACC) is located within the dorsomedial prefrontal cortex (PFC), and processes and facilitates goal-directed behaviors relating to emotion, reward, and motor control. However, it is unclear how ACC neurons dynamically encode motivated behavior during locomotion. In this study, we examined how information for locomotion and behavioral outcomes is temporally represented by individual and ensembles of ACC neurons in mice during a self-paced locomotor reward-based task. By recording and analyzing the activity of ACC neurons with a microdrive tetrode array while the mouse performed the locomotor task, we found that more than two-fifths of the neurons showed phasic activity relating to locomotion or the reward behavior. Some of these neurons showed significant differences in their firing rate depending on the behavioral outcome. Furthermore, by applying a demixed principal component analysis, the ACC population activity was decomposed into components representing locomotion and the previous/future outcome. These results indicated that ACC neurons dynamically integrate motor and behavioral inputs during goal-directed behaviors.
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The diagnosis of COVID-19 relies on the direct detection of SARS-CoV-2 RNA in respiratory specimens by RT-PCR. The pandemic spread of the disease caused an imbalance between demand and supply of materials and reagents needed for diagnostic purposes including swab sets. In a comparative effectiveness study, we conducted serial follow-up swabs in hospitalized laboratory-confirmed COVID-19 patients. We assessed the diagnostic performance of an in-house system developed according to recommendations by the US CDC. In a total of 96 serial swabs, we found significant differences in the accuracy of the different swab systems to generate a positive result in SARS-CoV-2 RT-PCR, ranging from around 50 to 80%. Of note, an in-house swab system was superior to most commercially available sets as reflected by significantly lower Ct values of viral genes. Thus, a simple combination of broadly available materials may enable diagnostic laboratories to bypass global limitations in the supply of swab sets.
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Teste de Ácido Nucleico para COVID-19/instrumentação , COVID-19/diagnóstico , Equipamentos Descartáveis/provisão & distribuição , Técnicas de Diagnóstico Molecular/instrumentação , SARS-CoV-2/isolamento & purificação , Teste de Ácido Nucleico para COVID-19/métodos , Técnicas de Laboratório Clínico , Testes Diagnósticos de Rotina , Genes Virais , Humanos , Técnicas de Diagnóstico Molecular/métodos , Controle de Qualidade , RNA Viral/análise , Reprodutibilidade dos Testes , Alocação de Recursos , Manejo de EspécimesRESUMO
Individuals with autism spectrum disorder (ASD) show impairments in processing social cues such as facial expressions and gaze direction. Several researchers have proposed that autistic traits form a continuum that may be distributed within the general, typically developed, population. Accordingly, several studies have indicated that typically developed individuals with high levels of self-reported autistic traits have autistic-like performance in a variety of paradigms. Here, we designed a gaze-cueing task to examine whether gaze-triggered orienting is related to the extent of typically developed (TD) individuals' autistic traits (determined by their AQ test scores) and whether it is modulated by previous eye contact and different facial expressions. At each trial, TD subjects observed faces with or without eye contact. This facial stimulus then gazed toward the left or right side. Finally, a target appeared on the left or right side of the display and reaction time (RT) to the target was measured. RTs were modulated by congruency between gazing directions and target locations, and by prior eye contact in the congruent trials. In addition, individuals with higher AQ scores were slower at detecting the target when the cue was a happy face. Furthermore, faster RTs in congruent trials were associated with one specific autistic trait (attention switching deficits). Together, these results indicate that autistic traits may influence performance in a gaze cueing task.
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Ras GTPase-activating protein-binding proteins 1 and 2 (G3BP1 and G3BP2, respectively) are widely recognized as core components of stress granules (SGs). We report that G3BPs reside at the cytoplasmic surface of lysosomes. They act in a non-redundant manner to anchor the tuberous sclerosis complex (TSC) protein complex to lysosomes and suppress activation of the metabolic master regulator mechanistic target of rapamycin complex 1 (mTORC1) by amino acids and insulin. Like the TSC complex, G3BP1 deficiency elicits phenotypes related to mTORC1 hyperactivity. In the context of tumors, low G3BP1 levels enhance mTORC1-driven breast cancer cell motility and correlate with adverse outcomes in patients. Furthermore, G3bp1 inhibition in zebrafish disturbs neuronal development and function, leading to white matter heterotopia and neuronal hyperactivity. Thus, G3BPs are not only core components of SGs but also a key element of lysosomal TSC-mTORC1 signaling.
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Proteínas Adaptadoras de Transdução de Sinal/metabolismo , DNA Helicases/metabolismo , Lisossomos/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , RNA Helicases/metabolismo , Proteínas com Motivo de Reconhecimento de RNA/metabolismo , Proteínas de Ligação a RNA/metabolismo , Transdução de Sinais , Esclerose Tuberosa/metabolismo , Sequência de Aminoácidos , Animais , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Grânulos Citoplasmáticos/efeitos dos fármacos , Grânulos Citoplasmáticos/metabolismo , DNA Helicases/química , Evolução Molecular , Feminino , Humanos , Insulina/farmacologia , Proteínas de Membrana Lisossomal/metabolismo , Lisossomos/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Fenótipo , Proteínas de Ligação a Poli-ADP-Ribose/química , RNA Helicases/química , Proteínas com Motivo de Reconhecimento de RNA/química , Ratos Wistar , Transdução de Sinais/efeitos dos fármacos , Peixe-Zebra/metabolismoRESUMO
The mechanistic target of rapamycin complex 1 (mTORC1) is a key metabolic hub that controls the cellular response to environmental cues by exerting its kinase activity on multiple substrates1-3. However, whether mTORC1 responds to diverse stimuli by differentially phosphorylating specific substrates is poorly understood. Here we show that transcription factor EB (TFEB), a master regulator of lysosomal biogenesis and autophagy4,5, is phosphorylated by mTORC1 via a substrate-specific mechanism that is mediated by Rag GTPases. Owing to this mechanism, the phosphorylation of TFEB-unlike other substrates of mTORC1, such as S6K and 4E-BP1- is strictly dependent on the amino-acid-mediated activation of RagC and RagD GTPases, but is insensitive to RHEB activity induced by growth factors. This mechanism has a crucial role in Birt-Hogg-Dubé syndrome, a disorder that is caused by mutations in the RagC and RagD activator folliculin (FLCN) and is characterized by benign skin tumours, lung and kidney cysts and renal cell carcinoma6,7. We found that constitutive activation of TFEB is the main driver of the kidney abnormalities and mTORC1 hyperactivity in a mouse model of Birt-Hogg-Dubé syndrome. Accordingly, depletion of TFEB in kidneys of these mice fully rescued the disease phenotype and associated lethality, and normalized mTORC1 activity. Our findings identify a mechanism that enables differential phosphorylation of mTORC1 substrates, the dysregulation of which leads to kidney cysts and cancer.
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Síndrome de Birt-Hogg-Dubé/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Animais , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/química , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/deficiência , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Síndrome de Birt-Hogg-Dubé/genética , Síndrome de Birt-Hogg-Dubé/patologia , Linhagem Celular , Modelos Animais de Doenças , Ativação Enzimática , Células HeLa , Humanos , Neoplasias Renais/metabolismo , Neoplasias Renais/patologia , Camundongos , Camundongos Knockout , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Fosforilação , Ligação Proteica , Proteínas Proto-Oncogênicas/deficiência , Proteínas Proto-Oncogênicas/genética , Proteína Enriquecida em Homólogo de Ras do Encéfalo/metabolismo , Especificidade por Substrato , Proteína 2 do Complexo Esclerose Tuberosa/metabolismo , Proteínas Supressoras de Tumor/deficiência , Proteínas Supressoras de Tumor/genéticaRESUMO
Lysosomes are key cellular catabolic centers that also perform fundamental metabolic, signaling and quality control functions. Lysosomes are not static and they respond dynamically to intra- and extracellular stimuli triggering changes in organelle numbers, size and position. Such physical changes have a strong impact on lysosomal activity ultimately influencing cellular homeostasis. In this review, we summarize the current knowledge on lysosomal size regulation, on its physiological role(s) and association to several disease conditions.