RESUMO
Most animals require sleep, and sleep loss induces serious pathophysiological consequences, including death. Previous experimental approaches for investigating sleep impacts in mice have been unable to persistently deprive animals of both rapid eye movement sleep (REMS) and non-rapid eye movement sleep (NREMS). Here, we report a "curling prevention by water" paradigm wherein mice remain awake 96% of the time. After 4 days of exposure, mice exhibit severe inflammation, and approximately 80% die. Sleep deprivation increases levels of prostaglandin D2 (PGD2) in the brain, and we found that elevated PGD2 efflux across the blood-brain-barrier-mediated by ATP-binding cassette subfamily C4 transporter-induces both accumulation of circulating neutrophils and a cytokine-storm-like syndrome. Experimental disruption of the PGD2/DP1 axis dramatically reduced sleep-deprivation-induced inflammation. Thus, our study reveals that sleep-related changes in PGD2 in the central nervous system drive profound pathological consequences in the peripheral immune system.
Assuntos
Privação do Sono , Animais , Camundongos , Citocinas/metabolismo , Inflamação , Prostaglandina D2 , Sono/fisiologia , Privação do Sono/genética , Privação do Sono/metabolismo , Síndrome , Humanos , Ratos , Linhagem Celular , Tempestades Ciclônicas , Neutrófilos/metabolismoRESUMO
Misfolded proteins are often cytotoxic, unless cellular systems prevent their accumulation. Data presented here uncover a mechanism by which defects in secretory proteins lead to a dramatic reduction in their mRNAs and protein expression. When mutant signal sequences fail to bind to the signal recognition particle (SRP) at the ribosome exit site, the nascent chain instead contacts Argonaute2 (Ago2), and the mutant mRNAs are specifically degraded. Severity of signal sequence mutations correlated with increased proximity of Ago2 to nascent chain and mRNA degradation. Ago2 knockdown inhibited degradation of the mutant mRNA, while overexpression of Ago2 or knockdown of SRP54 promoted degradation of secretory protein mRNA. The results reveal a previously unappreciated general mechanism of translational quality control, in which specific mRNA degradation preemptively regulates aberrant protein production (RAPP).
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Biossíntese de Proteínas , Dobramento de Proteína , Estabilidade de RNA , Partícula de Reconhecimento de Sinal/metabolismo , Sequência de Aminoácidos , Animais , Proteínas Argonautas/metabolismo , Cães , Células HeLa , Humanos , Dados de Sequência Molecular , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Alinhamento de SequênciaRESUMO
In mice and humans, sleep quantity is governed by genetic factors and exhibits age-dependent variation1-3. However, the core molecular pathways and effector mechanisms that regulate sleep duration in mammals remain unclear. Here, we characterize a major signalling pathway for the transcriptional regulation of sleep in mice using adeno-associated virus-mediated somatic genetics analysis4. Chimeric knockout of LKB1 kinase-an activator of AMPK-related protein kinase SIK35-7-in adult mouse brain markedly reduces the amount and delta power-a measure of sleep depth-of non-rapid eye movement sleep (NREMS). Downstream of the LKB1-SIK3 pathway, gain or loss-of-function of the histone deacetylases HDAC4 and HDAC5 in adult brain neurons causes bidirectional changes of NREMS amount and delta power. Moreover, phosphorylation of HDAC4 and HDAC5 is associated with increased sleep need, and HDAC4 specifically regulates NREMS amount in posterior hypothalamus. Genetic and transcriptomic studies reveal that HDAC4 cooperates with CREB in both transcriptional and sleep regulation. These findings introduce the concept of signalling pathways targeting transcription modulators to regulate daily sleep amount and demonstrate the power of somatic genetics in mouse sleep research.
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Transdução de Sinais , Duração do Sono , Transcrição Gênica , Animais , Camundongos , Regulação da Expressão Gênica , Fosforilação , Transdução de Sinais/fisiologia , Sono de Ondas Lentas/genética , Perfilação da Expressão GênicaRESUMO
Progress has been made in the elucidation of sleep and wakefulness regulation at the neurocircuit level1,2. However, the intracellular signalling pathways that regulate sleep and the neuron groups in which these intracellular mechanisms work remain largely unknown. Here, using a forward genetics approach in mice, we identify histone deacetylase 4 (HDAC4) as a sleep-regulating molecule. Haploinsufficiency of Hdac4, a substrate of salt-inducible kinase 3 (SIK3)3, increased sleep. By contrast, mice that lacked SIK3 or its upstream kinase LKB1 in neurons or with a Hdac4S245A mutation that confers resistance to phosphorylation by SIK3 showed decreased sleep. These findings indicate that LKB1-SIK3-HDAC4 constitute a signalling cascade that regulates sleep and wakefulness. We also performed targeted manipulation of SIK3 and HDAC4 in specific neurons and brain regions. This showed that SIK3 signalling in excitatory neurons located in the cerebral cortex and the hypothalamus positively regulates EEG delta power during non-rapid eye movement sleep (NREMS) and NREMS amount, respectively. A subset of transcripts biased towards synaptic functions was commonly regulated in cortical glutamatergic neurons through the expression of a gain-of-function allele of Sik3 and through sleep deprivation. These findings suggest that NREMS quantity and depth are regulated by distinct groups of excitatory neurons through common intracellular signals. This study provides a basis for linking intracellular events and circuit-level mechanisms that control NREMS.
Assuntos
Neurônios , Duração do Sono , Sono , Vigília , Animais , Camundongos , Eletroencefalografia , Neurônios/metabolismo , Neurônios/fisiologia , Sono/genética , Sono/fisiologia , Privação do Sono/genética , Vigília/genética , Vigília/fisiologia , Transdução de Sinais , Ritmo Delta , Córtex Cerebral/citologia , Córtex Cerebral/fisiologia , Hipotálamo/citologia , Hipotálamo/fisiologia , Ácido Glutâmico/metabolismo , Sono de Ondas Lentas/genética , Sono de Ondas Lentas/fisiologiaRESUMO
The discovery of RNA interference (RNAi) is among the most significant biomedical breakthroughs in recent history. Multiple classes of small RNA, including small-interfering RNA (siRNA), micro-RNA (miRNA), and piwi-interacting RNA (piRNA), play important roles in many fundamental biological and disease processes. Collective studies in multiple organisms, including plants, Drosophila, Caenorhabditis elegans, and mammals indicate that these pathways are highly conserved throughout evolution. Thus, scientists across disciplines have found novel pathways to unravel, new insights in probing pathology, and nascent technologies to develop. The field of RNAi also provides a clear framework for understanding fundamental principles of biochemistry. The current review highlights elegant, reason-based experimentation in discovering RNA-directed biological phenomena and the importance of robust assay development in translating these observations into mechanistic understanding. This biochemical template also provides a conceptual framework for overcoming emerging challenges in the field and for understanding an expanding small RNA world.
Assuntos
MicroRNAs/metabolismo , RNA Interferente Pequeno/metabolismo , Animais , Humanos , Redes e Vias Metabólicas , MicroRNAs/química , Interferência de RNA , RNA Interferente Pequeno/químicaRESUMO
The electrocatalytic hydrogenation (ECH) of furfural (FF) to furfuryl alcohol, which does not require additional hydrogen or high pressure, is a green and promising production route. In this study, we explore the effects of anions on FF ECH in two buffer electrolytes (KHCO3 and phosphate-buffered saline [PBS]). Anions influence the yield of furfuryl alcohol through molecular activation and adsorption. Molecular dynamics simulations show that bicarbonate is present in the first shell layer of the FF molecule and induces strong hydrogen bonding interactions. In contrast, hydrogen phosphate is present only in the second shell layer, resulting in weak hydrogen bonding interactions. Owing to the interfacial anions and hydrogen bonding, FF molecules exhibit strong flat adsorption on the electrode surface in the KHCO3 solution, while weak adsorption is observed in the PBS solution, as confirmed by operando synchrotron-radiation Fourier-transform infrared spectroscopy and in situ Raman spectroscopy. Density-functional theory calculations reveal that the overall anionic hydrogen bonding network promotes the activation of the carbonyl group in the FF molecule in KHCO3, whereas electrophilic activity is inhibited in PBS. Consequently, FF ECH demonstrates much faster kinetics in KHCO3, while it exhibits sluggish ECH kinetics and a severe hydrogen evolution reaction in PBS. This work introduces a new strategy to optimize the catalytic process through the modulation of the microenvironment.
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Hexamethylenetetramine (HMTA) is extensively used in the defense industry, medicines, food, plastics, rubber, and other applications. Traditional organic synthesis of HMTA relies on ammonia derived from the Haber process at high temperatures and pressures. In contrast, electrochemical methods enable a safe and green one-pot synthesis of HMTA from waste NO3-. However, HMTA synthesis through the electrochemical method is challenging owing to the complex reaction pathways involving C-N bond construction and ring formation. In this study, HMTA was efficiently synthesized over electrochemical oxidation-derived copper (e-OD-Cu), with a yield of 76.8% and a Faradaic efficiency of 74.9% at -0.30 VRHE. The catalytic mechanism and reaction pathway of HMTA synthesis on e-OD-Cu were investigated through a series of in situ characterization methods and density-functional theory calculations. The results demonstrated that the electrocatalytic synthesis of HMTA involved a tandem electrochemical-chemical reaction. Additionally, the results indicated that the presence of Cu vacancies enhanced substrate adsorption and inhibited the further hydrogenation of CâN. Overall, this study provides an electrocatalytic method for HMTA synthesis and an electrochemical strategy for constructing multiple C-N bonds.
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Aqueous electrochemical coupling reactions, which enable the green synthesis of complex organic compounds, will be a crucial tool in synthetic chemistry. However, a lack of informed approaches for screening suitable catalysts is a major obstacle to its development. Here, we propose a pioneering electrochemical reductive coupling reaction toward direct electrosynthesis of oxime from NOx and aldehyde. Through integrating experimental and theoretical methods, we screen out the optimal catalyst, i.e., metal Fe catalyst, that facilitates the enrichment and C-N coupling of key reaction intermediates, all leading to high yields (e.g., â¼99% yield of benzaldoxime) for the direct electrosynthesis of oxime over Fe. With a divided flow reactor, we achieve a high benzaldoxime production of 22.8 g h-1 gcat-1 in â¼94% isolated yield. This work not only paves the way to the industrial mass production of oxime via electrosynthesis but also offers references for the catalyst selection of other electrochemical coupling reactions.
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Persistently elevated glycolysis in kidney has been demonstrated to promote chronic kidney disease (CKD). However, the underlying mechanism remains largely unclear. Here, we observed that 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3), a key glycolytic enzyme, was remarkably induced in kidney proximal tubular cells (PTCs) following ischemia-reperfusion injury (IRI) in mice, as well as in multiple etiologies of patients with CKD. PFKFB3 expression was positively correlated with the severity of kidney fibrosis. Moreover, patients with CKD and mice exhibited increased urinary lactate/creatine levels and kidney lactate, respectively. PTC-specific deletion of PFKFB3 significantly reduced kidney lactate levels, mitigated inflammation and fibrosis, and preserved kidney function in the IRI mouse model. Similar protective effects were observed in mice with heterozygous deficiency of PFKFB3 or those treated with a PFKFB3 inhibitor. Mechanistically, lactate derived from PFKFB3-mediated tubular glycolytic reprogramming markedly enhanced histone lactylation, particularly H4K12la, which was enriched at the promoter of NF-κB signaling genes like Ikbkb, Rela, and Relb, activating their transcription and facilitating the inflammatory response. Further, PTC-specific deletion of PFKFB3 inhibited the activation of IKKß, I κ B α, and p65 in the IRI kidneys. Moreover, increased H4K12la levels were positively correlated with kidney inflammation and fibrosis in patients with CKD. These findings suggest that tubular PFKFB3 may play a dual role in enhancing NF-κB signaling by promoting both H4K12la-mediated gene transcription and its activation. Thus, targeting the PFKFB3-mediated NF-κB signaling pathway in kidney tubular cells could be a novel strategy for CKD therapy.
Assuntos
Modelos Animais de Doenças , Fibrose , Glicólise , Histonas , NF-kappa B , Fosfofrutoquinase-2 , Insuficiência Renal Crônica , Traumatismo por Reperfusão , Animais , Fosfofrutoquinase-2/genética , Fosfofrutoquinase-2/metabolismo , Insuficiência Renal Crônica/patologia , Insuficiência Renal Crônica/metabolismo , Humanos , Camundongos , Masculino , Traumatismo por Reperfusão/patologia , Traumatismo por Reperfusão/metabolismo , NF-kappa B/metabolismo , Histonas/metabolismo , Camundongos Knockout , Camundongos Endogâmicos C57BL , Transdução de Sinais , Túbulos Renais Proximais/patologia , Túbulos Renais Proximais/metabolismo , Ácido Láctico/metabolismo , Rim/patologia , Rim/metabolismoRESUMO
Acquiring a highly efficient electrocatalyst capable of sustaining prolonged operation under high current density is of paramount importance for the process of electrocatalytic water splitting. Herein, Fe-doped phosphide (Fe-Ni5P4) derived from the NiFc metal-organic framework (NiFc-MOF) (Fc: 1,1'-ferrocene dicarboxylate) shows high catalytic activity for overall water splitting (OWS). Fe-Ni5P4||Fe-Ni5P4 exhibits a low voltage of 1.72 V for OWS at 0.5 A cm-2 and permits stable operation for 2700 h in 1.0 m KOH. Remarkably, Fe-Ni5P4||Fe-Ni5P4 can sustain robust water splitting at an extra-large current density of 1 A cm-2 for 1170 h even in alkaline seawater. Theoretical calculations confirm that Fe doping simultaneously reduces the reaction barriers of coupling and desorption (O*âOOH*, OOH*âO2 *) in the oxygen evolution reaction (OER) and regulates the adsorption strength of the intermediates (H2O*, H*) in the hydrogen evolution reaction (HER), enabling Fe-Ni5P4 to possess excellent dual functional activity. This study offers a valuable reference for the advancement of highly durable electrocatalysts through the regulation derived from coordination frameworks, with significant implications for industrial applications and energy conversion technologies.
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The oxygen reduction reaction (ORR) catalyzed by transition-metal single-atom catalysts (SACs) is promising for practical applications in energy-conversion devices, but great challenges still remain due to the sluggish kinetics of OâO cleavage. Herein, a kind of high-density iron network-like sites catalysts are constructed with optimized intermetallic distances on an amino-functionalized carbon matrix (Fe-HDNSs). Quasi-in situ soft X-ray absorption spectroscopy and in situ synchrotron infrared characterizations demonstrate that the optimized intermetallic distances in Fe-HDNSs can in situ activate the molecular oxygen by fast electron compensation through the hybridized Fe 3dâO 2p, which efficiently facilitates the cleavage of the OâO bond to *O species and highly suppresses the side reactions for an accelerated kinetics of the 4e- ORR. As a result, the well-designed Fe-HDNSs catalysts exhibit superior performances with a half-wave potential of 0.89 V versus reversible hydrogen electrode (RHE) and a kinetic current density of 72 mA cm-2@0.80 V versus RHE, exceeding most of the noble-metal-free ORR catalysts. This work offers some new insights into the understanding of 4e- ORR kinetics and reaction pathways to boost electrochemical performances of SACs.
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Plant resistance (R) genes play a crucial role in the detection of effector proteins secreted by pathogens, either directly or indirectly, as well as in the subsequent activation of downstream defence mechanisms. However, little is known about how R genes regulate the defence responses of conifers, particularly Pinus massoniana, against the destructive pine wood nematode (PWN; Bursaphelenchus xylophilus). Here, we isolated and characterised PmHs1pro-1, a nematode-resistance gene of P. massoniana, using bioinformatics, molecular biology, histochemistry and transgenesis. Tissue-specific expressional pattern and localisation of PmHs1pro-1 suggested that it was a crucial positive regulator in response to PWN attack in resistant P. massoniana. Meanwhile, overexpression of PmHs1pro-1 was found to activate reactive oxygen species (ROS) metabolism-related enzymes and the expressional level of their key genes, including superoxide dismutase, peroxidase and catalase. In addition, we showed that PmHs1pro-1 directly recognised the effector protein BxSCD1of PWN, and induced the ROS burst responding to PWN invasion in resistant P. massoniana. Our findings illustrated the molecular framework of R genes directly recognising the effector protein of pathology in pine, which offered a novel insight into the plant-pathogen arms race.
Assuntos
Resistência à Doença , Regulação da Expressão Gênica de Plantas , Pinus , Doenças das Plantas , Proteínas de Plantas , Espécies Reativas de Oxigênio , Pinus/parasitologia , Pinus/genética , Pinus/fisiologia , Animais , Doenças das Plantas/parasitologia , Doenças das Plantas/imunologia , Resistência à Doença/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Espécies Reativas de Oxigênio/metabolismo , Tylenchida/fisiologia , Plantas Geneticamente Modificadas , Genes de Plantas , Tylenchoidea/fisiologiaRESUMO
OBJECTIVE: Using the preoperative pan-immune-inflammation value (PIV) and the monocyte to high-density lipoprotein ratio (MHR) to reflect inflammation, immunity, and cholesterol metabolism, we aim to develop and visualize a novel nomogram model for predicting the survival outcomes in patients with colorectal cancer (CRC). METHODS: A total of 172 patients with CRC who underwent radical resection were retrospectively analyzed. Survival analysis was conducted after patients were grouped according to the optimal cut-off values of PIV and MHR. Univariate and multivariate analyses were performed using Cox proportional hazards regression to screen the independent prognostic factors. Based on these factors, a nomogram was constructed and validated. RESULTS: The PIV was significantly associated with tumor location (P < 0.001), tumor maximum diameter (P = 0.008), and T stage (P = 0.019). The MHR was closely related to gender (P = 0.016), tumor maximum diameter (P = 0.002), and T stage (P = 0.038). Multivariate analysis results showed that PIV (Hazard Ratio (HR) = 2.476, 95% Confidence Interval (CI) = 1.410-4.348, P = 0.002), MHR (HR = 3.803, 95%CI = 1.609-8.989, P = 0.002), CEA (HR = 1.977, 95%CI = 1.121-3.485, P = 0.019), and TNM stage (HR = 1.759, 95%CI = 1.010-3.063, P = 0.046) were independent prognostic indicators for overall survival (OS). A nomogram incorporating these variables was developed, demonstrating robust predictive accuracy for OS. The area under the curve (AUC) values of the predictive model for 1-, 2-, and 3- year are 0.791,0.768,0.811, respectively. The calibration curves for the probability of survival at 1-, 2-, and 3- year presented a high degree of credibility. Furthermore, Decision curve analysis (DCA) for the probability of survival at 1-, 2-, and 3- year demonstrate the significant clinical utility in predicting survival outcomes. CONCLUSION: Preoperative PIV and MHR are independent risk factors for CRC prognosis. The novel developed nomogram demonstrates a robust predictive ability, offering substantial utility in facilitating the clinical decision-making process.
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Neoplasias Colorretais , Lipoproteínas HDL , Monócitos , Nomogramas , Humanos , Masculino , Feminino , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/cirurgia , Neoplasias Colorretais/sangue , Neoplasias Colorretais/patologia , Neoplasias Colorretais/imunologia , Estudos Retrospectivos , Pessoa de Meia-Idade , Idoso , Lipoproteínas HDL/sangue , Prognóstico , Inflamação/sangue , Período Pré-Operatório , Estadiamento de Neoplasias , Adulto , Modelos de Riscos ProporcionaisRESUMO
BACKGROUND: Different placenta accreta spectrum (PAS) subtypes pose varying surgical risks to the parturient. Machine learning model has the potential to diagnose PAS disorder. PURPOSE: To develop a cascaded deep semantic-radiomic-clinical (DRC) model for diagnosing PAS and its subtypes based on T2-weighted MRI. STUDY TYPE: Retrospective. POPULATION: 361 pregnant women (mean age: 33.10 ± 4.37 years), suspected of PAS, divided into segment training cohort (N = 40), internal training cohort (N = 139), internal testing cohort (N = 60), and external testing cohort (N = 122). FIELD STRENGTH/SEQUENCE: Coronal T2-weighted sequence at 1.5 T and 3.0 T. ASSESSMENT: Clinical characteristics such as history of uterine surgery and the presence of placenta previa, complete placenta previa and dangerous placenta previa were extracted from clinical records. The DRC model (incorporating radiomics, deep semantic features, and clinical characteristics), a cumulative radiological score method performed by radiologists, and other models (including a radiomics and clinical, the clinical, radiomics and deep learning models) were developed for PAS disorder diagnosing (existence of PAS and its subtypes). STATISTICAL TESTS: AUC, ACC, Student's t-test, the Mann-Whitney U test, chi-squared test, dice coefficient, intraclass correlation coefficients, least absolute shrinkage and selection operator regression, receiver operating characteristic curve, calibration curve with the Hosmer-Lemeshow test, decision curve analysis, DeLong test, and McNemar test. P < 0.05 indicated a significant difference. RESULTS: In PAS diagnosis, the DRC-1 outperformed than other models (AUC = 0.850 and 0.841 in internal and external testing cohorts, respectively). In PAS subtype classification (abnormal adherent placenta and abnormal invasive placenta), DRC-2 model performed similarly with radiologists (P = 0.773 and 0.579 in the internal testing cohort and P = 0.429 and 0.874 in the external testing cohort, respectively). DATA CONCLUSION: The DRC model offers efficiency and high diagnostic sensitivity in diagnosis, aiding in surgical planning. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY: Stage 2.
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BACKGROUND: Cerebral venous sinus thrombosis (CVST), a serious cerebrovascular and neurological emergency, is common in pregnant individuals and accounts for approximately 0.5-1.0% of all cerebrovascular diseases. However, CVST with cryptococcal meningoencephalitis in immunocompetent pregnant patients is rare. CASE PRESENTATION: A 30-year-old woman who was 33 weeks pregnant presented with recurrent dizziness, headache, and vomiting as the main clinical manifestations, all of which were initially nonspecific. After assessment of the cerebrospinal fluid, skull computerized tomography, magnetic resonance imaging, and other laboratory and imaging examinations, the patient was diagnosed with secondary pregnancy-related CVST with cryptococcal meningoencephalitis. Despite receiving potent anticoagulant and antifungal treatment, the patient's condition deteriorated, and the patient's family opted to cease treatment. CONCLUSIONS: We present a rare case of CVST with cryptococcal meningoencephalitis in an immunocompetent pregnant patient. The difficulty of diagnosing and treating secondary pregnancy-related CVST caused by cryptococcal meningoencephalitis, as well as the great challenges faced at present are highlighted. One crucial lesson from the present case is that when clinical and imaging signs are unusual for CVST during pregnancy, it is essential to account for the possibility of other central nervous system (CNS) diseases, such as CNS infections with Cryptococcus, which may cause CVST.
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Meningoencefalite , Complicações Infecciosas na Gravidez , Trombose dos Seios Intracranianos , Humanos , Feminino , Gravidez , Adulto , Trombose dos Seios Intracranianos/tratamento farmacológico , Trombose dos Seios Intracranianos/diagnóstico por imagem , Trombose dos Seios Intracranianos/etiologia , Trombose dos Seios Intracranianos/microbiologia , Meningoencefalite/microbiologia , Meningoencefalite/complicações , Meningoencefalite/tratamento farmacológico , Meningoencefalite/diagnóstico por imagem , Complicações Infecciosas na Gravidez/microbiologia , Complicações Infecciosas na Gravidez/tratamento farmacológico , Antifúngicos/uso terapêutico , Imageamento por Ressonância Magnética , Tomografia Computadorizada por Raios X , Criptococose/complicações , Criptococose/tratamento farmacológico , Criptococose/diagnóstico por imagem , Criptococose/diagnóstico , Criptococose/microbiologiaRESUMO
MicroRNAs (miRNAs) govern an expanding number of biological and disease processes. Understanding the mechanisms by which the miRNA pathway is regulated, therefore, represents an important area of investigation. We determined that the human miRNA-generating complex is comprised of Dicer and phospho-TRBP isoforms. Phosphorylation of TRBP is mediated by the mitogen-activated protein kinase (MAPK) Erk. Expression of phospho-mimic TRBP and TRBP phosphorylation enhanced miRNA production by increasing stability of the miRNA-generating complex. Mitogenic signaling in response to serum and the tumor promoter PMA was dependent on TRBP phosphorylation. These effects were accompanied by a coordinated increase in levels of growth-promoting miRNA and reduced expression of let-7 tumor suppressor miRNA. Conversely, pharmacological inhibition of MAPK/Erk resulted in an anti-growth miRNA profile. Taken together, these studies indicate that the MAPK/Erk pathway regulates the miRNA machinery and suggest a general principle, wherein signaling systems target the miRNA pathway to achieve biological responses.
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Sistema de Sinalização das MAP Quinases , MicroRNAs/metabolismo , Regulação da Expressão Gênica , Células HeLa , Humanos , Fosforilação , Isoformas de Proteínas/metabolismo , Proteínas de Ligação a RNA/metabolismo , Ribonuclease III/metabolismoRESUMO
Sleep and wake have global effects on brain physiology, from molecular changes1-4 and neuronal activities to synaptic plasticity3-7. Sleep-wake homeostasis is maintained by the generation of a sleep need that accumulates during waking and dissipates during sleep8-11. Here we investigate the molecular basis of sleep need using quantitative phosphoproteomic analysis of the sleep-deprived and Sleepy mouse models of increased sleep need. Sleep deprivation induces cumulative phosphorylation of the brain proteome, which dissipates during sleep. Sleepy mice, owing to a gain-of-function mutation in the Sik3 gene 12 , have a constitutively high sleep need despite increased sleep amount. The brain proteome of these mice exhibits hyperphosphorylation, similar to that seen in the brain of sleep-deprived mice. Comparison of the two models identifies 80 mostly synaptic sleep-need-index phosphoproteins (SNIPPs), in which phosphorylation states closely parallel changes of sleep need. SLEEPY, the mutant SIK3 protein, preferentially associates with and phosphorylates SNIPPs. Inhibition of SIK3 activity reduces phosphorylation of SNIPPs and slow wave activity during non-rapid-eye-movement sleep, the best known measurable index of sleep need, in both Sleepy mice and sleep-deprived wild-type mice. Our results suggest that phosphorylation of SNIPPs accumulates and dissipates in relation to sleep need, and therefore SNIPP phosphorylation is a molecular signature of sleep need. Whereas waking encodes memories by potentiating synapses, sleep consolidates memories and restores synaptic homeostasis by globally downscaling excitatory synapses4-6. Thus, the phosphorylation-dephosphorylation cycle of SNIPPs may represent a major regulatory mechanism that underlies both synaptic homeostasis and sleep-wake homeostasis.
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Encéfalo/metabolismo , Homeostase , Fosfoproteínas/análise , Fosfoproteínas/metabolismo , Proteoma/análise , Proteômica , Sono/fisiologia , Animais , Encéfalo/fisiologia , Mutação com Ganho de Função , Masculino , Consolidação da Memória/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Fosforilação , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteoma/metabolismo , Privação do Sono/metabolismo , Privação do Sono/fisiopatologia , Sinapses/fisiologia , Vigília/fisiologiaRESUMO
Recent studies suggest that the microprocessor (Drosha-DGCR8) complex can be recruited to chromatin to catalyze co-transcriptional processing of primary microRNAs (pri-miRNAs) in mammalian cells. However, the molecular mechanism of co-transcriptional miRNA processing is poorly understood. Here we find that HP1BP3, a histone H1-like chromatin protein, specifically associates with the microprocessor and promotes global miRNA biogenesis in human cells. Chromatin immunoprecipitation (ChIP) studies reveal genome-wide co-localization of HP1BP3 and Drosha and HP1BP3-dependent Drosha binding to actively transcribed miRNA loci. Moreover, HP1BP3 specifically binds endogenous pri-miRNAs and facilitates the Drosha/pri-miRNA association in vivo. Knockdown of HP1BP3 compromises pri-miRNA processing by causing premature release of pri-miRNAs from the chromatin. Taken together, these studies suggest that HP1BP3 promotes co-transcriptional miRNA processing via chromatin retention of nascent pri-miRNA transcripts. This work significantly expands the functional repertoire of the H1 family of proteins and suggests the existence of chromatin retention factors for widespread co-transcriptional miRNA processing.
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Cromatina/metabolismo , MicroRNAs/biossíntese , Proteínas Nucleares/metabolismo , Processamento Pós-Transcricional do RNA , Transcrição Gênica , Animais , Sítios de Ligação , Cromatina/genética , Imunoprecipitação da Cromatina , DNA Polimerase II/genética , DNA Polimerase II/metabolismo , Proteínas de Ligação a DNA , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Genoma Humano , Células HeLa , Humanos , MicroRNAs/genética , Proteínas Nucleares/genética , Ligação Proteica , Interferência de RNA , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Ribonuclease III/genética , Ribonuclease III/metabolismo , TransfecçãoRESUMO
BACKGROUND: Corticosteroids remain contentious as a therapeutic option for IgA nephropathy. We conducted a retrospective cohort study to explore whether corticosteroid therapy is efficient and safe for IgAN patients with moderate proteinuria. METHODS: A total of 336 patients with renal biopsy-confirmed IgAN, estimated glomerular filtration (eGFR) over 15 mL/min/1.73 m2 and urine protein levels of 0.75-3.5 g/d were enrolled. According to the treatment protocol, we classified the enrolled patients into two groups: one receiving corticosteroids and the other receiving supportive care. Complete remission, partial remission, and no remission were applied to describe the efficacy assessments. The endpoint was defined as a 40% reduction in eGFR, the onset of ESRD, or renal disease-related death. RESULTS: Clinical and pathological progression risk factors were higher in corticosteroid-treated individuals. Logistic regression analysis revealed that the corticosteroid group was considerably related to a higher remission rate after adjustment for confounding factors. The occurrence of serious adverse events between the two groups was not found to be statistically significantly different. Then, we matched 95 couples of patients with similar baseline levels in both groups by propensity score matching. The results showed that corticosteroid-treated patients showed higher overall and complete remission rates than untreated patients. However, due to the relatively short follow-up period, no significant differences in the incidence of endpoint and survival analyses have been observed thus far. CONCLUSION: Corticosteroid therapy may benefit IgAN patients with moderate proteinuria via proteinuria reduction and renal function preservation.
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Corticosteroides , Glomerulonefrite por IGA , Humanos , Corticosteroides/uso terapêutico , Taxa de Filtração Glomerular , Glomerulonefrite por IGA/complicações , Glomerulonefrite por IGA/diagnóstico , Glomerulonefrite por IGA/tratamento farmacológico , Proteinúria/tratamento farmacológico , Proteinúria/etiologia , Estudos RetrospectivosRESUMO
BACKGROUND: Autosomal recessive polycystic kidney disease (ARPKD) is a rare inherited cystic disease characterized by bilateral renal cyst formation and congenital liver fibrosis. Cardiovascular disorders such as noncompaction of ventricular myocardium (NVM) have not been reported with ARPKD. CASE PRESENTATION: A 5-month-old girl was examined after presenting with a fever and turbid urine for one day and was diagnosed as urinary tract infection. Urinary ultrasound showed multiple round, small cysts varying in size in both kidneys. Genetic testing revealed two heterozygous mutations and one exon deletion in the polycystic kidney and hepatic disease 1 gene, indicating a diagnosis of ARPKD. During hospitalization, she was found to have chronic heart failure after respiratory tract infection, with an ejection fraction of 29% and fraction shortening of 13%. When the patient was 15 months old, it was found that she had prominent trabeculations and deep intertrabecular recesses with the appearance of blood flow from the ventricular cavity into the intertrabecular recesses by echocardiography. The noncompaction myocardium was 0.716 cm and compaction myocardium was 0.221 cm (N/C = 3.27), indicating a diagnosis of NVM. Liver and kidney function remained normal during four-year follow-up. CONCLUSIONS: This is the first report of NVM in a patient with ARPKD. It is unsure if the coexistence of NVM and ARPKD is a coincidence or they are different manifestations of ciliary dysfunction in the heart and kidneys.