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Learning has been associated with modifications of synaptic and circuit properties, but the precise changes storing information in mammals have remained largely unclear. We combined genetically targeted voltage imaging with targeted optogenetic activation and silencing of pre- and post-synaptic neurons to study the mechanisms underlying hippocampal behavioral timescale plasticity. In mice navigating a virtual-reality environment, targeted optogenetic activation of individual CA1 cells at specific places induced stable representations of these places in the targeted cells. Optical elicitation, recording, and modulation of synaptic transmission in behaving mice revealed that activity in presynaptic CA2/3 cells was required for the induction of plasticity in CA1 and, furthermore, that during induction of these place fields in single CA1 cells, synaptic input from CA2/3 onto these same cells was potentiated. These results reveal synaptic implementation of hippocampal behavioral timescale plasticity and define a methodology to resolve synaptic plasticity during learning and memory in behaving mammals.
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Región CA1 Hipocampal , Hipocampo , Ratones , Animales , Región CA1 Hipocampal/fisiología , Hipocampo/fisiología , Plasticidad Neuronal/fisiología , Aprendizaje/fisiología , Neuronas , Transmisión Sináptica/fisiología , MamíferosRESUMEN
KCR channelrhodopsins (K+-selective light-gated ion channels) have received attention as potential inhibitory optogenetic tools but more broadly pose a fundamental mystery regarding how their K+ selectivity is achieved. Here, we present 2.5-2.7 Å cryo-electron microscopy structures of HcKCR1 and HcKCR2 and of a structure-guided mutant with enhanced K+ selectivity. Structural, electrophysiological, computational, spectroscopic, and biochemical analyses reveal a distinctive mechanism for K+ selectivity; rather than forming the symmetrical filter of canonical K+ channels achieving both selectivity and dehydration, instead, three extracellular-vestibule residues within each monomer form a flexible asymmetric selectivity gate, while a distinct dehydration pathway extends intracellularly. Structural comparisons reveal a retinal-binding pocket that induces retinal rotation (accounting for HcKCR1/HcKCR2 spectral differences), and design of corresponding KCR variants with increased K+ selectivity (KALI-1/KALI-2) provides key advantages for optogenetic inhibition in vitro and in vivo. Thus, discovery of a mechanism for ion-channel K+ selectivity also provides a framework for next-generation optogenetics.
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Channelrhodopsins , Rhinosporidium , Humanos , Channelrhodopsins/química , Channelrhodopsins/genética , Channelrhodopsins/metabolismo , Channelrhodopsins/ultraestructura , Microscopía por Crioelectrón , Canales Iónicos , Potasio/metabolismo , Rhinosporidium/químicaRESUMEN
ChRmine, a recently discovered pump-like cation-conducting channelrhodopsin, exhibits puzzling properties (large photocurrents, red-shifted spectrum, and extreme light sensitivity) that have created new opportunities in optogenetics. ChRmine and its homologs function as ion channels but, by primary sequence, more closely resemble ion pump rhodopsins; mechanisms for passive channel conduction in this family have remained mysterious. Here, we present the 2.0 Å resolution cryo-EM structure of ChRmine, revealing architectural features atypical for channelrhodopsins: trimeric assembly, a short transmembrane-helix 3, a twisting extracellular-loop 1, large vestibules within the monomer, and an opening at the trimer interface. We applied this structure to design three proteins (rsChRmine and hsChRmine, conferring further red-shifted and high-speed properties, respectively, and frChRmine, combining faster and more red-shifted performance) suitable for fundamental neuroscience opportunities. These results illuminate the conduction and gating of pump-like channelrhodopsins and point the way toward further structure-guided creation of channelrhodopsins for applications across biology.
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Channelrhodopsins/química , Channelrhodopsins/metabolismo , Activación del Canal Iónico , Animales , Channelrhodopsins/ultraestructura , Microscopía por Crioelectrón , Femenino , Células HEK293 , Humanos , Masculino , Ratones Endogámicos C57BL , Modelos Moleculares , Optogenética , Filogenia , Ratas Sprague-Dawley , Bases de Schiff/química , Células Sf9 , Relación Estructura-ActividadRESUMEN
Emotional states influence bodily physiology, as exemplified in the top-down process by which anxiety causes faster beating of the heart1-3. However, whether an increased heart rate might itself induce anxiety or fear responses is unclear3-8. Physiological theories of emotion, proposed over a century ago, have considered that in general, there could be an important and even dominant flow of information from the body to the brain9. Here, to formally test this idea, we developed a noninvasive optogenetic pacemaker for precise, cell-type-specific control of cardiac rhythms of up to 900 beats per minute in freely moving mice, enabled by a wearable micro-LED harness and the systemic viral delivery of a potent pump-like channelrhodopsin. We found that optically evoked tachycardia potently enhanced anxiety-like behaviour, but crucially only in risky contexts, indicating that both central (brain) and peripheral (body) processes may be involved in the development of emotional states. To identify potential mechanisms, we used whole-brain activity screening and electrophysiology to find brain regions that were activated by imposed cardiac rhythms. We identified the posterior insular cortex as a potential mediator of bottom-up cardiac interoceptive processing, and found that optogenetic inhibition of this brain region attenuated the anxiety-like behaviour that was induced by optical cardiac pacing. Together, these findings reveal that cells of both the body and the brain must be considered together to understand the origins of emotional or affective states. More broadly, our results define a generalizable approach for noninvasive, temporally precise functional investigations of joint organism-wide interactions among targeted cells during behaviour.
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Conducta Animal , Encéfalo , Emociones , Corazón , Animales , Ratones , Ansiedad/fisiopatología , Encéfalo/fisiología , Mapeo Encefálico , Emociones/fisiología , Corazón/fisiología , Conducta Animal/fisiología , Electrofisiología , Optogenética , Corteza Insular/fisiología , Frecuencia Cardíaca , Channelrhodopsins , Taquicardia/fisiopatología , Marcapaso ArtificialRESUMEN
The role of the nervous system in the regulation of cancer is increasingly appreciated. In gliomas, neuronal activity drives tumour progression through paracrine signalling factors such as neuroligin-3 and brain-derived neurotrophic factor1-3 (BDNF), and also through electrophysiologically functional neuron-to-glioma synapses mediated by AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid) receptors4,5. The consequent glioma cell membrane depolarization drives tumour proliferation4,6. In the healthy brain, activity-regulated secretion of BDNF promotes adaptive plasticity of synaptic connectivity7,8 and strength9-15. Here we show that malignant synapses exhibit similar plasticity regulated by BDNF. Signalling through the receptor tropomyosin-related kinase B16 (TrkB) to CAMKII, BDNF promotes AMPA receptor trafficking to the glioma cell membrane, resulting in increased amplitude of glutamate-evoked currents in the malignant cells. Linking plasticity of glioma synaptic strength to tumour growth, graded optogenetic control of glioma membrane potential demonstrates that greater depolarizing current amplitude promotes increased glioma proliferation. This potentiation of malignant synaptic strength shares mechanistic features with synaptic plasticity17-22 that contributes to memory and learning in the healthy brain23-26. BDNF-TrkB signalling also regulates the number of neuron-to-glioma synapses. Abrogation of activity-regulated BDNF secretion from the brain microenvironment or loss of glioma TrkB expression robustly inhibits tumour progression. Blocking TrkB genetically or pharmacologically abrogates these effects of BDNF on glioma synapses and substantially prolongs survival in xenograft models of paediatric glioblastoma and diffuse intrinsic pontine glioma. Together, these findings indicate that BDNF-TrkB signalling promotes malignant synaptic plasticity and augments tumour progression.
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Adaptación Fisiológica , Glioma , Plasticidad Neuronal , Sinapsis , Animales , Niño , Humanos , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina/metabolismo , Proliferación Celular , Progresión de la Enfermedad , Glioma/metabolismo , Glioma/patología , Ácido Glutámico/metabolismo , Neuronas/citología , Neuronas/metabolismo , Receptor trkB/genética , Receptor trkB/metabolismo , Receptores AMPA/metabolismo , Transducción de Señal , Sinapsis/metabolismo , Microambiente Tumoral , OptogenéticaRESUMEN
LIN28 plays a critical role in developmental transition, glucose metabolism, and tumorigenesis. At the molecular level, LIN28 is known to repress maturation of let-7 microRNAs and enhance translation of certain mRNAs. In this study, we obtain a genome-wide view of the molecular function of LIN28A in mouse embryonic stem cells by carrying out RNA crosslinking-immunoprecipitation-sequencing (CLIP-seq) and ribosome footprinting. We find that, in addition to let-7 precursors, LIN28A binds to a large number of spliced mRNAs. LIN28A recognizes AAGNNG, AAGNG, and less frequently UGUG, which are located in the terminal loop of a small hairpin. LIN28A is localized to the periendoplasmic reticulum (ER) area and inhibits translation of mRNAs that are destined for the ER, reducing the synthesis of transmembrane proteins, ER or Golgi lumen proteins, and secretory proteins. Our study suggests a selective regulatory mechanism for ER-associated translation and reveals an unexpected role of LIN28A as a global suppressor of genes in the secretory pathway.
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Biosíntesis de Proteínas , ARN Mensajero/metabolismo , Proteínas de Unión al ARN/metabolismo , Animales , Células Madre Embrionarias/metabolismo , Secuenciación de Nucleótidos de Alto Rendimiento , Inmunoprecipitación/métodos , Ratones , MicroARNs/metabolismo , Ribosomas/metabolismo , Vías Secretoras , Análisis de Secuencia de ARNRESUMEN
N6-methyladenosine (m6A) is the most abundant internal modification in RNAs and plays regulatory roles in a variety of biological and physiological processes. Despite its important roles, the molecular mechanism underlying m6A-mediated gene regulation is poorly understood. Here, we show that m6A-containing RNAs are subject to endoribonucleolytic cleavage via YTHDF2 (m6A reader protein), HRSP12 (adaptor protein), and RNase P/MRP (endoribonucleases). We demonstrate that HRSP12 functions as an adaptor to bridge YTHDF2 and RNase P/MRP, eliciting rapid degradation of YTHDF2-bound RNAs. Transcriptome-wide analyses show that m6A RNAs that are preferentially targeted for endoribonucleolytic cleavage have an HRSP12-binding site and a RNase P/MRP-directed cleavage site upstream and downstream of the YTHDF2-binding site, respectively. We also find that a subset of m6A-containing circular RNAs associates with YTHDF2 in an HRSP12-dependent manner and is selectively downregulated by RNase P/MRP. Thus, our data expand the known functions of RNase P/MRP to endoribonucleolytic cleavage of m6A RNAs.
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Adenosina/análogos & derivados , Proteínas de Choque Térmico/genética , Estabilidad del ARN/genética , Proteínas de Unión al ARN/genética , Ribonucleasa P/genética , Ribonucleasas/genética , Adenosina/genética , Dioxigenasa FTO Dependiente de Alfa-Cetoglutarato/genética , Sitios de Unión/genética , Escherichia coli/genética , Regulación de la Expresión Génica/genética , Células HeLa , Humanos , Metiltransferasas/genética , ARN/genética , Procesamiento Postranscripcional del ARN/genética , ARN Circular , Transcriptoma/genéticaRESUMEN
Chemotherapy typically destroys the tumor mass but rarely eradicates the cancer stem cells (CSCs) that can drive metastatic recurrence. A key current challenge is finding ways to eradicate CSCs and suppress their characteristics. Here, we report a prodrug, Nic-A, created by combining a carbonic anhydrase IX (CAIX) inhibitor, acetazolamide, with a signal transducer and transcriptional activator 3 (STAT3) inhibitor, niclosamide. Nic-A was designed to target triple-negative breast cancer (TNBC) CSCs and was found to inhibit both proliferating TNBC cells and CSCs via STAT3 dysregulation and suppression of CSC-like properties. Its use leads to a decrease in aldehyde dehydrogenase 1 activity, CD44high/CD24low stem-like subpopulations, and tumor spheroid-forming ability. TNBC xenograft tumors treated with Nic-A exhibited decreased angiogenesis and tumor growth, as well as decreased Ki-67 expression and increased apoptosis. In addition, distant metastases were suppressed in TNBC allografts derived from a CSC-enriched population. This study thus highlights a potential strategy for addressing CSC-based cancer recurrence.
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Profármacos , Neoplasias de la Mama Triple Negativas , Humanos , Línea Celular Tumoral , Neoplasias de la Mama Triple Negativas/metabolismo , Niclosamida/farmacología , Niclosamida/metabolismo , Niclosamida/uso terapéutico , Profármacos/uso terapéutico , Recurrencia Local de Neoplasia/patología , Factores de Transcripción/metabolismo , Células Madre Neoplásicas/metabolismo , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
A recent study by Hu et al. describes N6-methyladenosine (m6A)-selective allyl chemical labeling and sequencing (m6A-SAC-seq), which allows for quantitative, stoichiometric, and positional analyses of m6A at single-nucleotide resolution across the whole transcriptome level. Information on the m6A stoichiometry will provide additional layers of gene regulatory pathways mediated by m6A modification during diverse molecular, cellular, and physiological events.
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Adenosina , Transcriptoma , Adenosina/genética , Adenosina/metabolismo , Nucleótidos , Transcriptoma/genéticaRESUMEN
BACKGROUND AND AIMS: No medication has been found to reduce liver-related events. We evaluated the effect of sodium-glucose cotransporter-2 inhibitor (SGLT2i) on liver-related outcomes. APPROACH AND RESULTS: Single nucleotide polymorphisms associated with SGLT2 inhibition were identified, and a genetic risk score (GRS) was computed using the UK Biobank data (n=337,138). Two-sample Mendelian randomization (MR) was conducted using the FinnGen (n=218,792) database and the UK Biobank data. In parallel, a nationwide population-based study using the Korean National Health Insurance Service (NHIS) database was conducted. The development of liver-related complications (ie, hepatic decompensation, HCC, liver transplantation, and death) was compared between individuals with type 2 diabetes mellitus and steatotic liver diseases treated with SGLT2i (n=13,208) and propensity score-matched individuals treated with dipeptidyl peptidase-4 inhibitor (n=70,342). After computing GRS with 6 single nucleotide polymorphisms (rs4488457, rs80577326, rs11865835, rs9930811, rs34497199, and rs35445454), GRS-based MR showed that SGLT2 inhibition (per 1 SD increase of GRS, 0.1% lowering of HbA1c) was negatively associated with cirrhosis development (adjusted odds ratio=0.83, 95% CI=0.70-0.98, p =0.03) and this was consistent in the 2-sample MR (OR=0.73, 95% CI=0.60-0.90, p =0.003). In the Korean NHIS database, the risk of liver-related complications was significantly lower in the SGLT2i group than in the dipeptidyl peptidase-4 inhibitor group (adjusted hazard ratio=0.88, 95% CI=0.79-0.97, p =0.01), and this difference remained significant (adjusted hazard ratio=0.72-0.89, all p <0.05) across various sensitivity analyses. CONCLUSIONS: Both MRs using 2 European cohorts and a Korean nationwide population-based cohort study suggest that SGLT2 inhibition is associated with a lower risk of liver-related events.
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Diabetes Mellitus Tipo 2 , Análisis de la Aleatorización Mendeliana , Polimorfismo de Nucleótido Simple , Inhibidores del Cotransportador de Sodio-Glucosa 2 , Humanos , Inhibidores del Cotransportador de Sodio-Glucosa 2/uso terapéutico , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Femenino , Masculino , Persona de Mediana Edad , Estudios de Cohortes , Anciano , República de Corea/epidemiología , Inhibidores de la Dipeptidil-Peptidasa IV/uso terapéutico , Hepatopatías/genética , Hepatopatías/epidemiología , Hígado Graso/genética , AdultoRESUMEN
Structural variants (SVs) involving enhancer hijacking can rewire chromatin topologies to cause oncogene activation in human cancers, including hematologic malignancies; however, because of the lack of tools to assess their effects on gene regulation and chromatin organization, the molecular determinants for the functional output of enhancer hijacking remain poorly understood. Here, we developed a multimodal approach to integrate genome sequencing, chromosome conformation, chromatin state, and transcriptomic alteration for quantitative analysis of transcriptional effects and structural reorganization imposed by SVs in leukemic genomes. We identified known and new pathogenic SVs, including recurrent t(5;14) translocations that cause the hijacking of BCL11B enhancers for the allele-specific activation of TLX3 in a subtype of pediatric leukemia. Epigenetic perturbation of SV-hijacked BCL11B enhancers impairs TLX3 transcription, which are required for the growth of t(5;14) leukemia cells. By CRISPR engineering of patient-derived t(5;14) in isogenic leukemia cells, we uncovered a new mechanism whereby the transcriptional output of SV-induced BCL11B enhancer hijacking is dependent on the loss of DNA hypermethylation at the TLX3 promoter. Our results highlight the importance of the cooperation between genetic alteration and permissive chromatin as a critical determinant of SV-mediated oncogene activation, with implications for understanding aberrant gene transcription after epigenetic therapies in patients with leukemia. Hence, leveraging the interdependency of genetic alteration on chromatin variation may provide new opportunities to reprogram gene regulation as targeted interventions in human disease.
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Cromatina , Leucemia , Humanos , Niño , Cromatina/genética , Elementos de Facilitación Genéticos , Cromosomas/metabolismo , Factores de Transcripción/genética , Leucemia/genética , Proteínas Supresoras de Tumor/genética , Proteínas Represoras/genéticaRESUMEN
An RNA structure or modified RNA sequences can provide a platform for ribosome loading and internal translation initiation. The functional significance of internal translation has recently been highlighted by the discovery that a subset of circular RNAs (circRNAs) is internally translated. However, the molecular mechanisms underlying the internal initiation of translation in circRNAs remain unclear. Here, we identify eIF3g (a subunit of eIF3 complex) as a binding partner of eIF4A3, a core component of the exon-junction complex (EJC) that is deposited onto spliced mRNAs and plays multiple roles in the regulation of gene expression. The direct interaction between eIF4A3-eIF3g serves as a molecular linker between the eIF4A3 and eIF3 complex, thereby facilitating internal ribosomal entry. Protein synthesis from in vitro-synthesized circRNA demonstrates eIF4A3-driven internal translation, which relies on the eIF4A3-eIF3g interaction. Furthermore, our transcriptome-wide analysis shows that efficient polysomal association of endogenous circRNAs requires eIF4A3. Notably, a subset of endogenous circRNAs can express a full-length intact protein, such as ß-catenin, in an eIF4A3-dependent manner. Collectively, our results expand the understanding of the protein-coding potential of the human transcriptome, including circRNAs.
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Factor 3 de Iniciación Eucariótica , Factor 4A Eucariótico de Iniciación , ARN Circular , Humanos , Factor 3 de Iniciación Eucariótica/genética , Factor 3 de Iniciación Eucariótica/metabolismo , Factor 4A Eucariótico de Iniciación/metabolismo , Proteínas , Ribosomas/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismoRESUMEN
Circular RNA (circRNA) is a closed, single-stranded transcript widely detected in eukaryotes. Recent studies indicate that the levels of circRNAs change with age in various tissues in multiple species, ranging from nematodes to mammals. Here we discuss the functional roles of circRNAs in animal aging and longevity. We review studies regarding the differential expression of circRNAs that contributes to cellular senescence and the pathogenesis of aging-associated diseases. We explore the features of aging-associated circRNAs by discussing their potential as biomarkers of aging, tissue specificity, physiological roles, action mechanisms, and evolutionarily conserved characteristics. Our review provides insights into current progress in circRNA research and their significant functions in the aging process.
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Envejecimiento/genética , ARN Circular/fisiología , Animales , Caenorhabditis elegans/genética , Caenorhabditis elegans/fisiología , Drosophila melanogaster/genética , Drosophila melanogaster/fisiología , Marcadores Genéticos , Humanos , Mamíferos/genética , Mamíferos/fisiologíaRESUMEN
The INDUCER OF CBF EXPRESSION 1/C-REPEAT BINDING FACTOR (ICE1/CBF) pathway plays a crucial role in plant responses to cold stress, impacting growth and development. Here, we demonstrated that ATBS1-INTERACTING FACTOR 2 (AIF2), a non-DNA-binding basic helix-loop-helix transcription factor, positively regulates freezing tolerance through the ICE1/CBF-induced cold tolerance pathway in Arabidopsis. Cold stress transcriptionally upregulated AIF2 expression and induced AIF2 phosphorylation, thereby stabilizing the AIF2 protein during early stages of cold acclimation. The AIF2 loss-of-function mutant, aif2-1, exhibited heightened sensitivity to freezing before and after cold acclimation. In contrast, ectopic expression of AIF2, but not the C-terminal-deleted AIF2 variant, restored freezing tolerance. AIF2 enhanced ICE1 stability during cold acclimation and promoted the transcriptional expression of CBFs and downstream cold-responsive genes, ultimately enhancing plant tolerance to freezing stress. MITOGEN-ACTIVATED PROTEIN KINASES 3 and 6 (MPK3/6), known negative regulators of freezing tolerance, interacted with and phosphorylated AIF2, subjecting it to protein degradation. Furthermore, transient co-expression of MPK3/6 with AIF2 and ICE1 downregulated AIF2/ICE1-induced transactivation of CBF2 expression. AIF2 interacted preferentially with BIN2 and MPK3/6 during the early and later stages of cold acclimation, respectively, thereby differentially regulating AIF2 activity in a cold acclimation time-dependent manner. Moreover, AIF2 acted additively in a gain-of-function mutant of BRASSINAZOLE-RESISTANT 1 (BZR1; bzr1-1D) and a triple knockout mutant of BRASSINOSTEROID-INSENSITIVE 2 (BIN2) and its homologs (bin2bil1bil2) to induce CBFs-mediated freezing tolerance. This suggests that cold-induced AIF2 coordinates freezing tolerance along with BZR1 and BIN2, key positive and negative components, respectively, of brassinosteroid signaling pathways.
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BACKGROUND & AIMS: Recent studies reported that moderate HBV DNA levels are significantly associated with hepatocellular carcinoma (HCC) risk in hepatitis B e antigen (HBeAg)-positive, non-cirrhotic patients with chronic hepatitis B (CHB). We aimed to develop and validate a new risk score to predict HCC development using baseline moderate HBV DNA levels in patients entering into HBeAg-positive CHB from chronic infection. METHODS: This multicenter cohort study recruited 3,585 HBeAg-positive, non-cirrhotic patients who started antiviral treatment with entecavir or tenofovir disoproxil fumarate at phase change into CHB from chronic infection in 23 tertiary university-affiliated hospitals of South Korea (2012-2020). A new HCC risk score (PAGED-B) was developed (training cohort, n = 2,367) based on multivariable Cox models. Internal validation using bootstrap sampling and external validation (validation cohort, n = 1,218) were performed. RESULTS: Sixty (1.7%) patients developed HCC (median follow-up, 5.4 years). In the training cohort, age, gender, platelets, diabetes and moderate HBV DNA levels (5.00-7.99 log10 IU/ml) were independently associated with HCC development; the PAGED-B score (based on these five predictors) showed a time-dependent AUROC of 0.81 for the prediction of HCC development at 5 years. In the validation cohort, the AUROC of PAGED-B was 0.85, significantly higher than for other risk scores (PAGE-B, mPAGE-B, CAMD, and REAL-B). When stratified by the PAGED-B score, the HCC risk was significantly higher in high-risk patients than in low-risk patients (sub-distribution hazard ratio = 8.43 in the training and 11.59 in the validation cohorts, all p <0.001). CONCLUSIONS: The newly established PAGED-B score may enable risk stratification for HCC at the time of transition into HBeAg-positive CHB. IMPACT AND IMPLICATIONS: In this study, we developed and validated a new risk score to predict hepatocellular carcinoma (HCC) development in patients entering into hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB) from chronic infection. The newly established PAGED-B score, which included baseline moderate HBV DNA levels (5-8 log10 IU/ml), improved on the predictive performance of prior risk scores. Based on a patient's age, gender, diabetic status, platelet count, and moderate DNA levels (5-8 log10 IU/ml) at the phase change into CHB from chronic infection, the PAGED-B score represents a reliable and easily available risk score to predict HCC development during the first 5 years of antiviral treatment in HBeAg-positive patients entering into CHB. With a scoring range from 0 to 12 points, the PAGED-B score significantly differentiated the 5-year HCC risk: low <7 points and high ≥7 points.
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Carcinoma Hepatocelular , Hepatitis B Crónica , Neoplasias Hepáticas , Humanos , Preescolar , Carcinoma Hepatocelular/etiología , Carcinoma Hepatocelular/inducido químicamente , Hepatitis B Crónica/complicaciones , Hepatitis B Crónica/tratamiento farmacológico , Antígenos e de la Hepatitis B , ADN Viral , Neoplasias Hepáticas/etiología , Neoplasias Hepáticas/inducido químicamente , Estudios de Cohortes , Infección Persistente , Antivirales/uso terapéutico , Factores de Riesgo , Virus de la Hepatitis B/genéticaRESUMEN
BACKGROUND & AIMS: The risk of hepatocellular carcinoma (HCC) and hepatic decompensation persists after hepatitis B surface antigen (HBsAg) seroclearance. This study aimed to develop and validate a machine learning model to predict the risk of liver-related outcomes (LROs) following HBsAg seroclearance. METHODS: A total of 4,787 consecutive patients who achieved HBsAg seroclearance between 2000 and 2022 were enrolled from 6 centers in South Korea and a territory-wide database in Hong Kong, comprising the training (n=944), internal validation (n=1,102), and external validation (n=2,741) cohorts. Three machine learning-based models were developed and compared in each cohort. The primary outcome was the development of any LRO, including HCC, decompensation, and liver-related death. RESULTS: During a median follow-up of 55.2 (interquartile range=30.1-92.3) months, 123 LROs were confirmed (1.1%/person-year) in the Korean cohort. A model with the best predictive performance in the training cohort was selected as the final model (designated as PLAN-B-CURE), which was constructed using a gradient boosting algorithm and 7 variables (age, sex, diabetes, alcohol consumption, cirrhosis, albumin, and platelet count). Compared to previous HCC prediction models, PLAN-B-CURE showed significantly superior accuracy in the training cohort (c-index: 0.82 vs. 0.63-0.70, all P<0.001; area under the receiver operating characteristic curve: 0.86 vs. 0.62-0.72, all P<0.01; area under the precision-recall curve: 0.53 vs. 0.13-0.29, all P<0.01). PLAN-B-CURE showed a reliable calibration function (Hosmer-Lemeshow test P>0.05) and these results were reproduced in the internal and external validation cohorts. CONCLUSION: This novel machine learning model consisting of 7 variables provides reliable risk prediction of LRO after HBsAg seroclearance that can be used for personalized surveillance.
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Atopic dermatitis (AD) treatment has largely relied on non-specific broad immunosuppressants despite their long-term toxicities until the approval of dupilumab, which blocks IL-4 signaling to target Th2 cell responses. Here, we report the discovery of compound 4aa, a novel compound derived from the structure of chlorophyll a, and the efficacy of chlorophyll a to alleviate AD symptoms by oral administration in human AD patients. 4aa downregulated GATA3 and IL-4 in differentiating Th2 cells by potently blocking IL-4 receptor dimerization. In the murine model, oral administration of 4aa reduced the clinical severity of symptoms and scratching behavior by 76% and 72%, respectively. Notably, the elevated serum levels of Th2 cytokines reduced to levels similar to those in the normal group after oral administration of 4aa. Additionally, the toxicological studies showed favorable safety profiles and good tolerance. In conclusion, 4aa may be applied for novel therapeutic developments for patients with AD.
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Dermatitis Atópica , Humanos , Ratones , Animales , Dermatitis Atópica/tratamiento farmacológico , Células Th2 , Clorofila A , Interleucina-4 , Citocinas , Diferenciación CelularRESUMEN
A building block containing eight zincs and eight iodo groups (8 Zn) is obtained by the Zn complexation of a salen ligand bearing two additional hydroxy groups. Through the Sonogashira-Hagihara coupling of 8 Zn with 1,3,5,7-tetra(4-ethynylphenyl) adamantane, microporous organic polymers bearing octanuclear zinc clusters (MOP-8 Zn) are prepared, exhibiting a high surface area of 562 m2 g-1, microporosity, and a particulate morphology with an average diameter of 249 nm. The MOP-8 Zn exhibits significantly enhanced catalytic performance, compared to molecular counterparts, in the reductive carbon dioxide fixation to formamides, possibly due to the cooperative adsorption and confinement effect of networks on substrates.
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All-solid-state batteries (ASSBs) possess the advantage of ensuring safety while simultaneously maximizing energy density, making them suitable for next-generation battery models. In particular, sulfide solid electrolytes (SSEs) are viewed as promising candidates for ASSB electrolytes due to their excellent ionic conductivity. However, a limitation exists in the form of interfacial side reactions occurring between the SSEs and cathode active materials (CAMs), as well as the generation of sulfide-based gases within the SSE. These issues lead to a reduction in the capacity of CAMs and an increase in internal resistance within the cell. To address these challenges, cathode composite materials incorporating zinc oxide (ZnO) are fabricated, effectively reducing various side reactions occurring in CAMs. Acting as a semiconductor, ZnO helps mitigate the rapid oxidation of the solid electrolyte facilitated by an electronic pathway, thereby minimizing side reactions, while maintaining electron pathways to the active material. Additionally, it absorbs sulfide-based gases, thus protecting the lithium ions within CAMs. In this study, the mass spectrometer is employed to observe gas generation phenomena within the ASSB cell. Furthermore, a clear elucidation of the side reactions occurring at the cathode and the causes of capacity reduction in ASSB are provided through density functional theory calculations.
RESUMEN
OBJECTIVES: Catheter malposition after subclavian venous catheterization (SVC) is not uncommon and can lead to serious complications. This study hypothesized that the left access is superior to the right access in terms of catheter malposition after ultrasound-guided infraclavicular SVC due to the asymmetry of the bilateral brachiocephalic veins. DESIGN: Parallel-armed randomized controlled trial. SETTING: A tertiary referral hospital in Korea. PATIENTS: Patients 20-79 years old who were scheduled to undergo SVC under general anesthesia. INTERVENTIONS: Patients were randomly assigned to either the left (n = 224) or right (n = 225) SVC group. The primary outcome measure was the overall catheter malposition rate. The secondary outcome measures included catheter malposition rates into the ipsilateral internal jugular and contralateral brachiocephalic veins, other catheterization-related complications, and catheterization performance. MEASUREMENTS AND MAIN RESULTS: The catheter malposition rate was lower (10 [4.5%] vs. 31 [13.8%], p = 0.001), especially in the ipsilateral internal jugular vein (9 [4.0%] vs. 24 [10.7%], p = 0.007), in the left SVC group than in the right SVC group. In the left SVC group, catheterization success rates on the first pass (88 [39.3%] vs. 65 [28.9%], p = 0.020) and first-catheterization attempt (198 [88.4%] vs. 181 [80.4%], p = 0.020) were higher whereas times for vein visualization (30 s [18-50] vs. 20 s [13-38], p < 0.001) and total catheterization (134 s [113-182] vs. 132 s [103-170], p = 0.034) were longer. There were no significant differences in other catheterization performance and catheterization-related complications between the two groups. CONCLUSIONS: These findings strengthen the rationale for choosing the left access over the right access for ultrasound-guided infraclavicular SVC.