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1.
Cell ; 184(14): 3731-3747.e21, 2021 07 08.
Artículo en Inglés | MEDLINE | ID: mdl-34214470

RESUMEN

In motor neuroscience, state changes are hypothesized to time-lock neural assemblies coordinating complex movements, but evidence for this remains slender. We tested whether a discrete change from more autonomous to coherent spiking underlies skilled movement by imaging cerebellar Purkinje neuron complex spikes in mice making targeted forelimb-reaches. As mice learned the task, millimeter-scale spatiotemporally coherent spiking emerged ipsilateral to the reaching forelimb, and consistent neural synchronization became predictive of kinematic stereotypy. Before reach onset, spiking switched from more disordered to internally time-locked concerted spiking and silence. Optogenetic manipulations of cerebellar feedback to the inferior olive bi-directionally modulated neural synchronization and reaching direction. A simple model explained the reorganization of spiking during reaching as reflecting a discrete bifurcation in olivary network dynamics. These findings argue that to prepare learned movements, olivo-cerebellar circuits enter a self-regulated, synchronized state promoting motor coordination. State changes facilitating behavioral transitions may generalize across neural systems.


Asunto(s)
Movimiento/fisiología , Red Nerviosa/fisiología , Potenciales de Acción/fisiología , Animales , Calcio/metabolismo , Cerebelo/fisiología , Sincronización Cortical , Miembro Anterior/fisiología , Interneuronas/fisiología , Aprendizaje , Ratones Endogámicos C57BL , Ratones Transgénicos , Modelos Neurológicos , Actividad Motora/fisiología , Núcleo Olivar/fisiología , Optogenética , Células de Purkinje/fisiología , Conducta Estereotipada , Análisis y Desempeño de Tareas
2.
Cell ; 174(6): 1436-1449.e20, 2018 09 06.
Artículo en Inglés | MEDLINE | ID: mdl-30146163

RESUMEN

Synaptic vesicle and active zone proteins are required for synaptogenesis. The molecular mechanisms for coordinated synthesis of these proteins are not understood. Using forward genetic screens, we identified the conserved THO nuclear export complex (THOC) as an important regulator of presynapse development in C. elegans dopaminergic neurons. In THOC mutants, synaptic messenger RNAs are retained in the nucleus, resulting in dramatic decrease of synaptic protein expression, near complete loss of synapses, and compromised dopamine function. CRE binding protein (CREB) interacts with THOC to mark synaptic transcripts for efficient nuclear export. Deletion of Thoc5, a THOC subunit, in mouse dopaminergic neurons causes severe defects in synapse maintenance and subsequent neuronal death in the substantia nigra compacta. These cellular defects lead to abrogated dopamine release, ataxia, and animal death. Together, our results argue that nuclear export mechanisms can select specific mRNAs and be a rate-limiting step for neuronal differentiation and survival.


Asunto(s)
Proteínas de Caenorhabditis elegans/genética , Neuronas Dopaminérgicas/metabolismo , Proteínas Nucleares/genética , Sinapsis/metabolismo , Transporte Activo de Núcleo Celular , Esclerosis Amiotrófica Lateral/metabolismo , Esclerosis Amiotrófica Lateral/patología , Animales , Caenorhabditis elegans , Proteínas de Caenorhabditis elegans/metabolismo , Señalización del Calcio , Núcleo Celular/metabolismo , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/genética , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Mutagénesis , Mutación Missense , Proteínas Nucleares/deficiencia , Proteínas Nucleares/metabolismo , Subunidades de Proteína/deficiencia , Subunidades de Proteína/genética , Subunidades de Proteína/metabolismo
3.
Cell ; 168(1-2): 86-100.e15, 2017 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-27916275

RESUMEN

Type 1 diabetes is characterized by the destruction of pancreatic ß cells, and generating new insulin-producing cells from other cell types is a major aim of regenerative medicine. One promising approach is transdifferentiation of developmentally related pancreatic cell types, including glucagon-producing α cells. In a genetic model, loss of the master regulatory transcription factor Arx is sufficient to induce the conversion of α cells to functional ß-like cells. Here, we identify artemisinins as small molecules that functionally repress Arx by causing its translocation to the cytoplasm. We show that the protein gephyrin is the mammalian target of these antimalarial drugs and that the mechanism of action of these molecules depends on the enhancement of GABAA receptor signaling. Our results in zebrafish, rodents, and primary human pancreatic islets identify gephyrin as a druggable target for the regeneration of pancreatic ß cell mass from α cells.


Asunto(s)
Artemisininas/farmacología , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Modelos Animales de Enfermedad , Receptores de GABA-A/metabolismo , Transducción de Señal , Animales , Arteméter , Artemisininas/administración & dosificación , Proteínas Portadoras/metabolismo , Transdiferenciación Celular/efectos de los fármacos , Células Cultivadas , Diabetes Mellitus/tratamiento farmacológico , Diabetes Mellitus Tipo 1/patología , Perfilación de la Expresión Génica , Proteínas de Homeodominio/metabolismo , Humanos , Insulina/genética , Insulina/metabolismo , Islotes Pancreáticos/efectos de los fármacos , Proteínas de la Membrana/metabolismo , Ratones , Estabilidad Proteica/efectos de los fármacos , Ratas , Análisis de la Célula Individual , Factores de Transcripción/metabolismo , Pez Cebra , Ácido gamma-Aminobutírico/metabolismo
4.
Cell ; 167(6): 1650-1662.e15, 2016 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-27912066

RESUMEN

Electrophysiological field potential dynamics are of fundamental interest in basic and clinical neuroscience, but how specific cell types shape these dynamics in the live brain is poorly understood. To empower mechanistic studies, we created an optical technique, TEMPO, that records the aggregate trans-membrane voltage dynamics of genetically specified neurons in freely behaving mice. TEMPO has >10-fold greater sensitivity than prior fiber-optic techniques and attains the noise minimum set by quantum mechanical photon shot noise. After validating TEMPO's capacity to track established oscillations in the delta, theta, and gamma frequency bands, we compared the D1- and D2-dopamine-receptor-expressing striatal medium spiny neurons (MSNs), which are interspersed and electrically indistinguishable. Unexpectedly, MSN population dynamics exhibited two distinct coherent states that were commonly indiscernible in electrical recordings and involved synchronized hyperpolarizations across both MSN subtypes. Overall, TEMPO allows the deconstruction of normal and pathologic neurophysiological states into trans-membrane voltage activity patterns of specific cell types.


Asunto(s)
Ondas Encefálicas , Ratones/fisiología , Neurofisiología/métodos , Imagen de Colorante Sensible al Voltaje/métodos , Animales , Femenino , Masculino , Ratones Endogámicos BALB C
5.
Mol Cell ; 83(21): 3869-3884.e7, 2023 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-37797622

RESUMEN

Effective immunity requires the innate immune system to distinguish foreign nucleic acids from cellular ones. Cellular double-stranded RNAs (dsRNAs) are edited by the RNA-editing enzyme ADAR1 to evade being recognized as viral dsRNA by cytoplasmic dsRNA sensors, including MDA5 and PKR. The loss of ADAR1-mediated RNA editing of cellular dsRNA activates MDA5. Additional RNA-editing-independent functions of ADAR1 have been proposed, but a specific mechanism has not been delineated. We now demonstrate that the loss of ADAR1-mediated RNA editing specifically activates MDA5, whereas loss of the cytoplasmic ADAR1p150 isoform or its dsRNA-binding activity enabled PKR activation. Deleting both MDA5 and PKR resulted in complete rescue of the embryonic lethality of Adar1p150-/- mice to adulthood, contrasting with the limited or no rescue by removing MDA5 or PKR alone. Our findings demonstrate that MDA5 and PKR are the primary in vivo effectors of fatal autoinflammation following the loss of ADAR1p150.


Asunto(s)
Inmunidad Innata , ARN Bicatenario , Animales , Ratones , Adenosina Desaminasa/genética , Adenosina Desaminasa/metabolismo , Citoplasma/metabolismo , Inmunidad Innata/genética , ARN Bicatenario/genética
6.
Genes Dev ; 36(15-16): 916-935, 2022 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-36175033

RESUMEN

Alternative polyadenylation (APA) generates transcript isoforms that differ in the position of the 3' cleavage site, resulting in the production of mRNA isoforms with different length 3' UTRs. Although widespread, the role of APA in the biology of cells, tissues, and organisms has been controversial. We identified >500 Drosophila genes that express mRNA isoforms with a long 3' UTR in proliferating spermatogonia but a short 3' UTR in differentiating spermatocytes due to APA. We show that the stage-specific choice of the 3' end cleavage site can be regulated by the arrangement of a canonical polyadenylation signal (PAS) near the distal cleavage site but a variant or no recognizable PAS near the proximal cleavage site. The emergence of transcripts with shorter 3' UTRs in differentiating cells correlated with changes in expression of the encoded proteins, either from off in spermatogonia to on in spermatocytes or vice versa. Polysome gradient fractionation revealed >250 genes where the long 3' UTR versus short 3' UTR mRNA isoforms migrated differently, consistent with dramatic stage-specific changes in translation state. Thus, the developmentally regulated choice of an alternative site at which to make the 3' end cut that terminates nascent transcripts can profoundly affect the suite of proteins expressed as cells advance through sequential steps in a differentiation lineage.


Asunto(s)
Células Madre Adultas , Isoformas de ARN , Regiones no Traducidas 3'/genética , Células Madre Adultas/metabolismo , Animales , Masculino , Poliadenilación , Isoformas de Proteínas/genética , Isoformas de ARN/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo
7.
Nature ; 608(7923): 569-577, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35922514

RESUMEN

A major challenge in human genetics is to identify the molecular mechanisms of trait-associated and disease-associated variants. To achieve this, quantitative trait locus (QTL) mapping of genetic variants with intermediate molecular phenotypes such as gene expression and splicing have been widely adopted1,2. However, despite successes, the molecular basis for a considerable fraction of trait-associated and disease-associated variants remains unclear3,4. Here we show that ADAR-mediated adenosine-to-inosine RNA editing, a post-transcriptional event vital for suppressing cellular double-stranded RNA (dsRNA)-mediated innate immune interferon responses5-11, is an important potential mechanism underlying genetic variants associated with common inflammatory diseases. We identified and characterized 30,319 cis-RNA editing QTLs (edQTLs) across 49 human tissues. These edQTLs were significantly enriched in genome-wide association study signals for autoimmune and immune-mediated diseases. Colocalization analysis of edQTLs with disease risk loci further pinpointed key, putatively immunogenic dsRNAs formed by expected inverted repeat Alu elements as well as unexpected, highly over-represented cis-natural antisense transcripts. Furthermore, inflammatory disease risk variants, in aggregate, were associated with reduced editing of nearby dsRNAs and induced interferon responses in inflammatory diseases. This unique directional effect agrees with the established mechanism that lack of RNA editing by ADAR1 leads to the specific activation of the dsRNA sensor MDA5 and subsequent interferon responses and inflammation7-9. Our findings implicate cellular dsRNA editing and sensing as a previously underappreciated mechanism of common inflammatory diseases.


Asunto(s)
Adenosina Desaminasa , Predisposición Genética a la Enfermedad , Enfermedades del Sistema Inmune , Inflamación , Edición de ARN , ARN Bicatenario , Adenosina/metabolismo , Adenosina Desaminasa/genética , Adenosina Desaminasa/metabolismo , Elementos Alu/genética , Enfermedades Autoinmunes/genética , Enfermedades Autoinmunes/inmunología , Enfermedades Autoinmunes/patología , Estudio de Asociación del Genoma Completo , Humanos , Enfermedades del Sistema Inmune/genética , Enfermedades del Sistema Inmune/inmunología , Enfermedades del Sistema Inmune/patología , Inmunidad Innata , Inflamación/genética , Inflamación/inmunología , Inflamación/patología , Inosina/metabolismo , Helicasa Inducida por Interferón IFIH1/metabolismo , Interferones/genética , Interferones/inmunología , Sitios de Carácter Cuantitativo/genética , Edición de ARN/genética , ARN Bicatenario/genética , Proteínas de Unión al ARN/metabolismo
8.
EMBO J ; 42(8): e112387, 2023 04 17.
Artículo en Inglés | MEDLINE | ID: mdl-36872914

RESUMEN

The cGAS-STING pathway plays an important role in host defense by sensing pathogen DNA, inducing type I IFNs, and initiating autophagy. However, the molecular mechanism of autophagosome formation in cGAS-STING pathway-induced autophagy is still unclear. Here, we report that STING directly interacts with WIPI2, which is the key protein for LC3 lipidation in autophagy. Binding to WIPI2 is necessary for STING-induced autophagosome formation but does not affect STING activation and intracellular trafficking. In addition, the specific interaction between STING and the PI3P-binding motif of WIPI2 leads to the competition of WIPI2 binding between STING and PI3P, and mutual inhibition between STING-induced autophagy and canonical PI3P-dependent autophagy. Furthermore, we show that the STING-WIPI2 interaction is required for the clearance of cytoplasmic DNA and the attenuation of cGAS-STING signaling. Thus, the direct interaction between STING and WIPI2 enables STING to bypass the canonical upstream machinery to induce LC3 lipidation and autophagosome formation.


Asunto(s)
Autofagosomas , Autofagia , Proteínas de la Membrana , Autofagosomas/metabolismo , Autofagia/fisiología , ADN/metabolismo , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Nucleotidiltransferasas/metabolismo , Humanos
9.
Nature ; 600(7887): 54-58, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34666338

RESUMEN

The Moon has a magmatic and thermal history that is distinct from that of the terrestrial planets1. Radioisotope dating of lunar samples suggests that most lunar basaltic magmatism ceased by around 2.9-2.8 billion years ago (Ga)2,3, although younger basalts between 3 Ga and 1 Ga have been suggested by crater-counting chronology, which has large uncertainties owing to the lack of returned samples for calibration4,5. Here we report a precise lead-lead age of 2,030 ± 4 million years ago for basalt clasts returned by the Chang'e-5 mission, and a 238U/204Pb ratio (µ value)6 of about 680 for a source that evolved through two stages of differentiation. This is the youngest crystallization age reported so far for lunar basalts by radiometric dating, extending the duration of lunar volcanism by approximately 800-900 million years. The µ value of the Chang'e-5 basalt mantle source is within the range of low-titanium and high-titanium basalts from Apollo sites (µ value of about 300-1,000), but notably lower than those of potassium, rare-earth elements and phosphorus (KREEP) and high-aluminium basalts7 (µ value of about 2,600-3,700), indicating that the Chang'e-5 basalts were produced by melting of a KREEP-poor source. This age provides a pivotal calibration point for crater-counting chronology in the inner Solar System and provides insight on the volcanic and thermal history of the Moon.

11.
Proc Natl Acad Sci U S A ; 121(15): e2317769121, 2024 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-38564633

RESUMEN

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition characterized by social and communication deficits and repetitive behaviors. The genetic heterogeneity of ASD presents a challenge to the development of an effective treatment targeting the underlying molecular defects. ASD gating charge mutations in the KCNQ/KV7 potassium channel cause gating pore currents (Igp) and impair action potential (AP) firing of dopaminergic neurons in brain slices. Here, we investigated ASD gating charge mutations of the voltage-gated SCN2A/NaV1.2 brain sodium channel, which ranked high among the ion channel genes with mutations in individuals with ASD. Our results show that ASD mutations in the gating charges R2 in Domain-II (R853Q), and R1 (R1626Q) and R2 (R1629H) in Domain-IV of NaV1.2 caused Igp in the resting state of ~0.1% of the amplitude of central pore current. The R1626Q mutant also caused significant changes in the voltage dependence of fast inactivation, and the R1629H mutant conducted proton-selective Igp. These potentially pathogenic Igp were exacerbated by the absence of the extracellular Mg2+ and Ca2+. In silico simulation of the effects of these mutations in a conductance-based single-compartment cortical neuron model suggests that the inward Igp reduces the time to peak for the first AP in a train, increases AP rates during a train of stimuli, and reduces the interstimulus interval between consecutive APs, consistent with increased neural excitability and altered input/output relationships. Understanding this common pathophysiological mechanism among different voltage-gated ion channels at the circuit level will give insights into the underlying mechanisms of ASD.


Asunto(s)
Trastorno del Espectro Autista , Trastorno Autístico , Canales de Sodio Activados por Voltaje , Humanos , Trastorno del Espectro Autista/genética , Trastorno Autístico/genética , Encéfalo , Mutación
12.
Hum Mol Genet ; 33(10): 905-918, 2024 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-38449065

RESUMEN

Mutations in AIFM1, encoding for apoptosis-inducing factor (AIF), cause AUNX1, an X-linked neurologic disorder with late-onset auditory neuropathy (AN) and peripheral neuropathy. Despite significant research on AIF, there are limited animal models with the disrupted AIFM1 representing the corresponding phenotype of human AUNX1, characterized by late-onset hearing loss and impaired auditory pathways. Here, we generated an Aifm1 p.R450Q knock-in mouse model (KI) based on the human AIFM1 p.R451Q mutation. Hemizygote KI male mice exhibited progressive hearing loss from P30 onward, with greater severity at P60 and stabilization until P210. Additionally, muscle atrophy was observed at P210. These phenotypic changes were accompanied by a gradual reduction in the number of spiral ganglion neuron cells (SGNs) at P30 and ribbons at P60, which coincided with the translocation of AIF into the nucleus starting from P21 and P30, respectively. The SGNs of KI mice at P210 displayed loss of cytomembrane integrity, abnormal nuclear morphology, and dendritic and axonal demyelination. Furthermore, the inner hair cells and myelin sheath displayed abnormal mitochondrial morphology, while fibroblasts from KI mice showed impaired mitochondrial function. In conclusion, we successfully generated a mouse model recapitulating AUNX1. Our findings indicate that disruption of Aifm1 induced the nuclear translocation of AIF, resulting in the impairment in the auditory pathway.


Asunto(s)
Factor Inductor de la Apoptosis , Modelos Animales de Enfermedad , Pérdida Auditiva , Animales , Humanos , Masculino , Ratones , Factor Inductor de la Apoptosis/genética , Factor Inductor de la Apoptosis/metabolismo , Núcleo Celular/metabolismo , Núcleo Celular/genética , Técnicas de Sustitución del Gen , Células Ciliadas Auditivas Internas/metabolismo , Células Ciliadas Auditivas Internas/patología , Pérdida Auditiva/genética , Pérdida Auditiva/patología , Pérdida Auditiva/metabolismo , Atrofia Muscular/genética , Atrofia Muscular/patología , Atrofia Muscular/metabolismo , Mutación , Transporte de Proteínas , Ganglio Espiral de la Cóclea/metabolismo , Ganglio Espiral de la Cóclea/patología
13.
RNA ; 30(5): 500-511, 2024 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-38531645

RESUMEN

Innate immunity must be tightly regulated to enable sensitive pathogen detection while averting autoimmunity triggered by pathogen-like host molecules. A hallmark of viral infection, double-stranded RNAs (dsRNAs) are also abundantly encoded in mammalian genomes, necessitating surveillance mechanisms to distinguish "self" from "nonself." ADAR1, an RNA editing enzyme, has emerged as an essential safeguard against dsRNA-induced autoimmunity. By converting adenosines to inosines (A-to-I) in long dsRNAs, ADAR1 covalently marks endogenous dsRNAs, thereby blocking the activation of the cytoplasmic dsRNA sensor MDA5. Moreover, beyond its editing function, ADAR1 binding to dsRNA impedes the activation of innate immune sensors PKR and ZBP1. Recent landmark studies underscore the utility of silencing ADAR1 for cancer immunotherapy, by exploiting the ADAR1-dependence developed by certain tumors to unleash an antitumor immune response. In this perspective, we summarize the genetic and mechanistic evidence for ADAR1's multipronged role in suppressing dsRNA-mediated autoimmunity and explore the evolving roles of ADAR1 as an immuno-oncology target.


Asunto(s)
Adenosina Desaminasa , Edición de ARN , Animales , Adenosina Desaminasa/metabolismo , Inmunidad Innata/genética , Helicasa Inducida por Interferón IFIH1/genética , Mamíferos/genética , ARN Bicatenario/genética , Humanos
14.
Mol Cell ; 69(2): 279-291.e5, 2018 01 18.
Artículo en Inglés | MEDLINE | ID: mdl-29351847

RESUMEN

Sustained energy starvation leads to activation of AMP-activated protein kinase (AMPK), which coordinates energy status with numerous cellular processes including metabolism, protein synthesis, and autophagy. Here, we report that AMPK phosphorylates the histone methyltransferase EZH2 at T311 to disrupt the interaction between EZH2 and SUZ12, another core component of the polycomb repressive complex 2 (PRC2), leading to attenuated PRC2-dependent methylation of histone H3 at Lys27. As such, PRC2 target genes, many of which are known tumor suppressors, were upregulated upon T311-EZH2 phosphorylation, which suppressed tumor cell growth both in cell culture and mouse xenografts. Pathologically, immunohistochemical analyses uncovered a positive correlation between AMPK activity and pT311-EZH2, and higher pT311-EZH2 correlates with better survival in both ovarian and breast cancer patients. Our finding suggests that AMPK agonists might be promising sensitizers for EZH2-targeting cancer therapies.


Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Animales , Carcinogénesis/genética , Ciclo Celular , Línea Celular Tumoral , Proliferación Celular , Metilación de ADN , Proteínas de Unión al ADN/metabolismo , Proteína Potenciadora del Homólogo Zeste 2/genética , Proteína Potenciadora del Homólogo Zeste 2/fisiología , Epigénesis Genética , Femenino , Histonas/metabolismo , Humanos , Ratones , Proteínas de Neoplasias , Proteínas Nucleares/metabolismo , Oncogenes , Neoplasias Ováricas/metabolismo , Fosforilación , Complejo Represivo Polycomb 2/metabolismo , Complejo Represivo Polycomb 2/fisiología , Factores de Transcripción , Regulación hacia Arriba
15.
Proc Natl Acad Sci U S A ; 120(39): e2307722120, 2023 09 26.
Artículo en Inglés | MEDLINE | ID: mdl-37725654

RESUMEN

Single-cell RNA-seq (scRNA-seq) analysis of multiple samples separately can be costly and lead to batch effects. Exogenous barcodes or genome-wide RNA mutations can be used to demultiplex pooled scRNA-seq data, but they are experimentally or computationally challenging and limited in scope. Mitochondrial genomes are small but diverse, providing concise genotype information. We developed "mitoSplitter," an algorithm that demultiplexes samples using mitochondrial RNA (mtRNA) variants, and demonstrated that mtRNA variants can be used to demultiplex large-scale scRNA-seq data. Using affordable computational resources, mitoSplitter can accurately analyze 10 samples and 60,000 cells in 6 h. To avoid the batch effects from separated experiments, we applied mitoSplitter to analyze the responses of five non-small cell lung cancer cell lines to BET (Bromodomain and extraterminal) chemical degradation in a multiplexed fashion. We found the synthetic lethality of TOP2A inhibition and BET chemical degradation in BET inhibitor-resistant cells. The result indicates that mitoSplitter can accelerate the application of scRNA-seq assays in biomedical research.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Humanos , ARN Mitocondrial , Análisis de Expresión Génica de una Sola Célula , Mitocondrias/genética
16.
J Neurosci ; 44(4)2024 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-38050110

RESUMEN

Working memory (WM) maintenance relies on multiple brain regions and inter-regional communications. The hippocampus and entorhinal cortex (EC) are thought to support this operation. Besides, EC is the main gateway for information between the hippocampus and neocortex. However, the circuit-level mechanism of this interaction during WM maintenance remains unclear in humans. To address these questions, we recorded the intracranial electroencephalography from the hippocampus and EC while patients (N = 13, six females) performed WM tasks. We found that WM maintenance was accompanied by enhanced theta/alpha band (2-12 Hz) phase synchronization between the hippocampus to the EC. The Granger causality and phase slope index analyses consistently showed that WM maintenance was associated with theta/alpha band-coordinated unidirectional influence from the hippocampus to the EC. Besides, this unidirectional inter-regional communication increased with WM load and predicted WM load during memory maintenance. These findings demonstrate that WM maintenance in humans engages the hippocampal-entorhinal circuit, with the hippocampus influencing the EC in a load-dependent manner.


Asunto(s)
Hipocampo , Memoria a Corto Plazo , Femenino , Humanos , Encéfalo , Electrocorticografía , Corteza Entorrinal , Electroencefalografía , Ritmo Teta
17.
J Virol ; 98(1): e0155823, 2024 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-38174926

RESUMEN

Enterovirus A71 (EV-A71) can induce severe neurological complications and even fatal encephalitis in children, and it has caused several large outbreaks in Taiwan since 1998. We previously generated VP1 codon-deoptimized (VP1-CD) reverse genetics (rg) EV-A71 viruses (rgEV-A71s) that harbor a high-fidelity (HF) 3D polymerase. These VP1-CD-HF rgEV-A71s showed lower replication kinetics in vitro and decreased virulence in an Institute of Cancer Research (ICR) mouse model of EV-A71 infection, while still retaining their antigenicity in comparison to the wild-type virus. In this study, we aimed to further investigate the humoral and cellular immune responses elicited by VP1-CD-HF rgEV-A71s to assess the potential efficacy of these EV-A71 vaccine candidates. Following intraperitoneal (i.p.) injection of VP1-CD-HF rgEV-A71s in mice, we observed a robust induction of EV-A71-specific neutralizing IgG antibodies in the antisera after 21 days. Splenocytes isolated from VP1-CD-HF rgEV-A71s-immunized mice exhibited enhanced proliferative activities and cytokine production (IL-2, IFN-γ, IL-4, IL-6, and TNF-α) upon re-stimulation with VP1-CD-HF rgEV-A71, as compared to control mice treated with adjuvant only. Importantly, administration of antisera from VP1-CD-HF rgEV-A71s-immunized mice protected against lethal EV-A71 challenge in neonatal mice. These findings highlight that our generated VP1-CD-HF rgEV-A71 viruses are capable of inducing both cellular and humoral immune responses, supporting their potential as next-generation EV-A71 vaccines for combating EV-A71 infection.IMPORTANCEEV-A71 can cause severe neurological diseases and cause death in young children. Here, we report the development of synthetic rgEV-A71s with the combination of codon deoptimization and high-fidelity (HF) substitutions that generate genetically stable reverse genetics (rg) viruses as potential attenuated vaccine candidates. Our work provides insight into the development of low-virulence candidate vaccines through a series of viral genetic editing for maintaining antigenicity and genome stability and suggests a strategy for the development of an innovative next-generation vaccine against EV-A71.


Asunto(s)
Proteínas de la Cápside , Enterovirus Humano A , Infecciones por Enterovirus , ARN Polimerasa Dependiente del ARN , Animales , Ratones , Anticuerpos Antivirales/inmunología , Codón , Enterovirus Humano A/genética , Infecciones por Enterovirus/inmunología , Vacunas Atenuadas , Proteínas de la Cápside/genética , Inmunidad Humoral , Inmunidad Celular , Anticuerpos Neutralizantes/inmunología , Vacunas Virales , Ratones Endogámicos ICR , Ratones Endogámicos BALB C , ARN Polimerasa Dependiente del ARN/genética
18.
J Virol ; 98(6): e0053124, 2024 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-38709106

RESUMEN

Human coronavirus (hCoV) OC43 is endemic to global populations and usually causes asymptomatic or mild upper respiratory tract illness. Here, we demonstrate the neutralization efficacy of isolated nanobodies from alpacas immunized with the S1B and S1C domain of the hCoV-OC43 spike glycoprotein. A total of 40 nanobodies bound to recombinant OC43 protein with affinities ranging from 1 to 149 nM. Two nanobodies WNb 293 and WNb 294 neutralized virus at 0.21 and 1.79 nM, respectively. Intranasal and intraperitoneal delivery of WNb 293 fused to an Fc domain significantly reduced nasal viral load in a mouse model of hCoV-OC43 infection. Using X-ray crystallography, we observed that WNb 293 bound to an epitope on the OC43 S1B domain, distal from the sialoglycan-binding site involved in host cell entry. This result suggests that neutralization mechanism of this nanobody does not involve disruption of glycan binding. Our work provides characterization of nanobodies against hCoV-OC43 that blocks virus entry and reduces viral loads in vivo and may contribute to future nanobody-based therapies for hCoV-OC43 infections. IMPORTANCE: The pandemic potential presented by coronaviruses has been demonstrated by the ongoing COVID-19 pandemic and previous epidemics caused by severe acute respiratory syndrome coronavirus and Middle East respiratory syndrome coronavirus. Outside of these major pathogenic coronaviruses, there are four endemic coronaviruses that infect humans: hCoV-OC43, hCoV-229E, hCoV-HKU1, and hCoV-NL63. We identified a collection of nanobodies against human coronavirus OC43 (hCoV-OC43) and found that two high-affinity nanobodies potently neutralized hCoV-OC43 at low nanomolar concentrations. Prophylactic administration of one neutralizing nanobody reduced viral loads in mice infected with hCoV-OC43, showing the potential for nanobody-based therapies for hCoV-OC43 infections.


Asunto(s)
Anticuerpos Neutralizantes , Anticuerpos Antivirales , Camélidos del Nuevo Mundo , Infecciones por Coronavirus , Coronavirus Humano OC43 , Anticuerpos de Dominio Único , Glicoproteína de la Espiga del Coronavirus , Carga Viral , Animales , Anticuerpos de Dominio Único/inmunología , Ratones , Anticuerpos Neutralizantes/inmunología , Coronavirus Humano OC43/inmunología , Humanos , Anticuerpos Antivirales/inmunología , Camélidos del Nuevo Mundo/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Infecciones por Coronavirus/inmunología , Infecciones por Coronavirus/prevención & control , Infecciones por Coronavirus/virología , Femenino , Epítopos/inmunología , Cristalografía por Rayos X , Internalización del Virus/efectos de los fármacos , Modelos Animales de Enfermedad , Ratones Endogámicos BALB C
19.
Brief Bioinform ; 24(3)2023 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-36960771

RESUMEN

MOTIVATION: Histones are the chief protein components of chromatin, and the chemical modifications on histones crucially influence the transcriptional state of related genes. Histone modifying enzyme (HME), responsible for adding or removing the chemical labels, has emerged as a very important class of drug target, with a few HME inhibitors launched as anti-cancerous drugs and tens of molecules under clinical trials. To accelerate the drug discovery process of HME inhibitors, machine learning-based predictive models have been developed to enrich the active molecules from vast chemical space. However, the number of compounds with known activity distributed largely unbalanced among different HMEs, particularly with many targets of less than a hundred active samples. In this case, it is difficult to build effective virtual screening models directly based on machine learning. RESULTS: To this end, we propose a new Meta-learning-based Histone Modifying Enzymes Inhibitor prediction method (MetaHMEI). Our proposed MetaHMEI first uses a self-supervised pre-training approach to obtain high-quality molecular substructure embeddings from a large unlabeled chemical dataset. Then, MetaHMEI exploits a Transformer-based encoder and meta-learning framework to build a prediction model. MetaHMEI allows the effective transfer of the prior knowledge learned from HMEs with sufficient samples to HMEs with a small number of samples, so the proposed model can produce accurate predictions for HMEs with limited data. Extensive experimental results on our collected and curated HMEs datasets show that MetaHMEI is better than other methods in the case of few-shot learning. Furthermore, we applied MetaHMEI in the virtual screening process of histone JMJD3 inhibitors and successfully obtained three small molecule inhibitors, further supporting the validity of our model.


Asunto(s)
Cromatina , Histonas , Histonas/metabolismo , Descubrimiento de Drogas/métodos , Inhibidores Enzimáticos/farmacología
20.
Hepatology ; 2024 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-38904485

RESUMEN

BACKGROUND AND AIMS: The surface antigen of hepatitis B virus (HBsAg) serves as an important immune-modulatory factor in chronic hepatitis B (CHB). One aspect of such modulation may act through monocytes which are the major antigen presenting cells (APCs) taking up HBsAg. There is evidence for the encapsulation of hepatocellular miRNAs by HBsAg particles, while its pathobiological significance is unclear. Here, we characterized the miRNA profile in CHB patients and probed their association with liver inflammation. APPROACHES AND RESULTS: We collected plasma from treatment-naive CHB patients (n=110) and quantified total/HBsAg-enveloped miRNAs by qRT-PCR and plasma cytokines by ELISA. The biological effects of HBsAg-delivered miRNAs in monocytes were evaluated by multiple approaches. The clinical significance of candidate miRNAs and cytokines was corroborated in patients with HBV-associated advanced liver diseases. The plasma miRNA profile showed two major clusters, one significantly associated with HBsAg titer and the other correlated with liver inflammation. Among HBsAg-carried miRNAs, miR-939 displayed most significant correlation with IL-8. Mechanistically, miR-939 in subviral particles enters monocytes and significantly augments IL-8 production via the MAPK p38 signaling pathway. Finally, the findings that miR-939 positively correlated with IL-8 level and inflammation/fibrosis stage in the cohort of HBV-associated advanced liver diseases support its causative role in the progression of liver diseases. CONCLUSION: HBsAg particles carry hepatocellular miRNAs, including miR-939, which enter monocytes and alter their functional status such as IL-8 secretion. Our findings demonstrate that HBsAg-miR-939-IL-8 axis may play a crucial role in HBV-induced hepatic necro-inflammation and progression of advanced liver diseases.

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