RESUMEN
The coronavirus disease 2019 (COVID-19) pandemic continues worldwide with many variants arising, some of which are variants of concern (VOCs). A recent VOC, omicron (B.1.1.529), which obtains a large number of mutations in the receptor-binding domain (RBD) of the spike protein, has risen to intense scientific and public attention. Here, we studied the binding properties between the human receptor ACE2 (hACE2) and the VOC RBDs and resolved the crystal and cryoelectron microscopy structures of the omicron RBD-hACE2 complex as well as the crystal structure of the delta RBD-hACE2 complex. We found that, unlike alpha, beta, and gamma, omicron RBD binds to hACE2 at a similar affinity to that of the prototype RBD, which might be due to compensation of multiple mutations for both immune escape and transmissibility. The complex structures of omicron RBD-hACE2 and delta RBD-hACE2 reveal the structural basis of how RBD-specific mutations bind to hACE2.
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Enzima Convertidora de Angiotensina 2/química , Receptores Virales/química , SARS-CoV-2/química , Secuencia de Aminoácidos , Microscopía por Crioelectrón , Humanos , Modelos Moleculares , Mutación/genética , Filogenia , Unión Proteica , Dominios Proteicos , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/ultraestructura , Electricidad Estática , Homología Estructural de ProteínaRESUMEN
Breakthrough infections by SARS-CoV-2 variants become the global challenge for pandemic control. Previously, we developed the protein subunit vaccine ZF2001 based on the dimeric receptor-binding domain (RBD) of prototype SARS-CoV-2. Here, we developed a chimeric RBD-dimer vaccine approach to adapt SARS-CoV-2 variants. A prototype-Beta chimeric RBD-dimer was first designed to adapt the resistant Beta variant. Compared with its homotypic forms, the chimeric vaccine elicited broader sera neutralization of variants and conferred better protection in mice. The protection of the chimeric vaccine was further verified in macaques. This approach was generalized to develop Delta-Omicron chimeric RBD-dimer to adapt the currently prevalent variants. Again, the chimeric vaccine elicited broader sera neutralization of SARS-CoV-2 variants and conferred better protection against challenge by either Delta or Omicron SARS-CoV-2 in mice. The chimeric approach is applicable for rapid updating of immunogens, and our data supported the use of variant-adapted multivalent vaccine against circulating and emerging variants.
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COVID-19 , Vacunas , Animales , Anticuerpos Neutralizantes , Anticuerpos Antivirales , COVID-19/prevención & control , Vacunas contra la COVID-19 , Humanos , Ratones , SARS-CoV-2/genéticaRESUMEN
There is an urgent need for vaccines against coronavirus disease 2019 (COVID-19) because of the ongoing SARS-CoV-2 pandemic. Among all approaches, a messenger RNA (mRNA)-based vaccine has emerged as a rapid and versatile platform to quickly respond to this challenge. Here, we developed a lipid nanoparticle-encapsulated mRNA (mRNA-LNP) encoding the receptor binding domain (RBD) of SARS-CoV-2 as a vaccine candidate (called ARCoV). Intramuscular immunization of ARCoV mRNA-LNP elicited robust neutralizing antibodies against SARS-CoV-2 as well as a Th1-biased cellular response in mice and non-human primates. Two doses of ARCoV immunization in mice conferred complete protection against the challenge of a SARS-CoV-2 mouse-adapted strain. Additionally, ARCoV is manufactured as a liquid formulation and can be stored at room temperature for at least 1 week. ARCoV is currently being evaluated in phase 1 clinical trials.
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ARN Mensajero/genética , ARN Viral/genética , Vacunas Sintéticas/inmunología , Vacunas Virales/inmunología , Animales , Anticuerpos Neutralizantes/inmunología , Sitios de Unión , Vacunas contra la COVID-19 , Chlorocebus aethiops , Infecciones por Coronavirus/genética , Infecciones por Coronavirus/inmunología , Infecciones por Coronavirus/prevención & control , Femenino , Células HEK293 , Células HeLa , Humanos , Inmunogenicidad Vacunal , Inyecciones Intramusculares , Macaca fascicularis , Masculino , Ratones , Ratones Endogámicos ICR , Nanopartículas/química , ARN Mensajero/metabolismo , ARN Viral/metabolismo , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/metabolismo , Células TH1/inmunología , Potencia de la Vacuna , Vacunas Sintéticas/administración & dosificación , Vacunas Sintéticas/genética , Células Vero , Vacunas Virales/administración & dosificación , Vacunas Virales/genéticaRESUMEN
The global severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic requires effective therapies against coronavirus disease 2019 (COVID-19), and neutralizing antibodies are a promising therapy. A noncompeting pair of human neutralizing antibodies (B38 and H4) blocking SARS-CoV-2 binding to its receptor, ACE2, have been described previously. Here, we develop bsAb15, a bispecific monoclonal antibody (bsAb) based on B38 and H4. bsAb15 has greater neutralizing efficiency than these parental antibodies, results in less selective pressure and retains neutralizing ability to most SARS-CoV-2 variants of concern (with more potent neutralizing activity against the Delta variant). We also selected for escape mutants of the two parental mAbs, a mAb cocktail and bsAb15, demonstrating that bsAb15 can efficiently neutralize all single-mAb escape mutants. Furthermore, prophylactic and therapeutic application of bsAb15 reduced the viral titer in infected nonhuman primates and human ACE2 transgenic mice. Therefore, this bsAb is a feasible and effective strategy to treat and prevent severe COVID-19.
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Anticuerpos Biespecíficos/inmunología , Anticuerpos Monoclonales/inmunología , Anticuerpos Antivirales/inmunología , SARS-CoV-2/inmunología , Animales , Anticuerpos Biespecíficos/química , Anticuerpos Biespecíficos/genética , Anticuerpos Monoclonales/química , Anticuerpos Monoclonales/genética , Anticuerpos Neutralizantes/genética , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/química , Anticuerpos Antivirales/genética , COVID-19/inmunología , COVID-19/patología , COVID-19/prevención & control , COVID-19/virología , Clonación Molecular , Modelos Animales de Enfermedad , Relación Dosis-Respuesta Inmunológica , Epítopos , Humanos , Macaca mulatta , Ratones , Pruebas de Neutralización , Ingeniería de Proteínas/métodos , Relación Estructura-ActividadRESUMEN
Mxra8 is a receptor for multiple arthritogenic alphaviruses that cause debilitating acute and chronic musculoskeletal disease in humans. Herein, we present a 2.2 Å resolution X-ray crystal structure of Mxra8 and 4 to 5 Å resolution cryo-electron microscopy reconstructions of Mxra8 bound to chikungunya (CHIKV) virus-like particles and infectious virus. The Mxra8 ectodomain contains two strand-swapped Ig-like domains oriented in a unique disulfide-linked head-to-head arrangement. Mxra8 binds by wedging into a cleft created by two adjacent CHIKV E2-E1 heterodimers in one trimeric spike and engaging a neighboring spike. Two binding modes are observed with the fully mature VLP, with one Mxra8 binding with unique contacts. Only the high-affinity binding mode was observed in the complex with infectious CHIKV, as viral maturation and E3 occupancy appear to influence receptor binding-site usage. Our studies provide insight into how Mxra8 binds CHIKV and creates a path for developing alphavirus entry inhibitors.
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Virus Chikungunya/química , Proteínas de la Membrana/química , Proteínas del Envoltorio Viral/química , Virus Chikungunya/metabolismo , Virus Chikungunya/ultraestructura , Microscopía por Crioelectrón , Células HEK293 , Humanos , Proteínas de la Membrana/metabolismo , Dominios Proteicos , Proteínas del Envoltorio Viral/metabolismoRESUMEN
The dorsal aorta (DA) is the first major blood vessel to develop in the embryonic cardiovascular system. Its formation is governed by a coordinated process involving the migration, specification, and arrangement of angioblasts into arterial and venous lineages, a process conserved across species. While vascular endothelial growth factor a (VEGF-A) drives DA specification and formation, the kinases involved in this process remain ambiguous. Thus, we investigated the role of protein kinase B, Akt, in zebrafish by generating a quadruple mutant (aktΔ/Δ), where expression and activity of all akt genes-akt 1, 2, 3a, and 3b are strongly decreased. Live imaging of developing aktΔ/Δ DA uncovers early arteriovenous malformations. Single-cell RNA sequencing analysis of aktΔ/Δ endothelial cells corroborates the impairment of arterial, yet not venous, cell specification. Notably, endothelial specific expression of ligand-independent activation of Notch or constitutively active Akt1 were sufficient to reestablish normal arterial specification in aktΔ/Δ. The Akt-loss-of-function mutant unveils that Akt kinase can act upstream of Notch in arterial endothelial cells, and is involved in proper embryonic artery specification. This sheds light on cardiovascular development, revealing a mechanism behind congenital malformations.
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Although interferon-induced proteins with tetratricopeptide repeats (IFIT proteins) inhibit infection of many viruses by recognizing their RNA, the regulatory mechanisms involved remain unclear. Here we report a crystal structure of cap 0 (m7GpppN) RNA bound to human IFIT1 in complex with the C-terminal domain of human IFIT3. Structural, biochemical, and genetic studies suggest that IFIT3 binding to IFIT1 has dual regulatory functions: (1) extending the half-life of IFIT1 and thereby increasing its steady-state amounts in cells; and (2) allosterically regulating the IFIT1 RNA-binding channel, thereby enhancing the specificity of recognition for cap 0 but not cap 1 (m7GpppNm) or 5'-ppp RNA. Mouse Ifit3 lacks this key C-terminal domain and does not bind mouse Ifit1. The IFIT3 interaction with IFIT1 is important for restricting infection of viruses lacking 2'-O methylation in their RNA cap structures. Our experiments establish differences in the regulation of IFIT1 orthologs and define targets for modulation of human IFIT protein activity.
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Proteínas Portadoras/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteínas de Unión al ARN/metabolismo , Proteínas Adaptadoras Transductoras de Señales , Animales , Proteínas Portadoras/química , Proteínas Portadoras/genética , Regulación de la Expresión Génica , Interacciones Huésped-Patógeno/genética , Humanos , Péptidos y Proteínas de Señalización Intracelular/química , Péptidos y Proteínas de Señalización Intracelular/genética , Metilación , Ratones , Modelos Moleculares , Conformación Molecular , Unión Proteica , Dominios y Motivos de Interacción de Proteínas , Estabilidad Proteica , ARN/química , ARN/genética , ARN/metabolismo , Proteínas de Unión al ARN/química , Proteínas de Unión al ARN/genética , Especificidad de la Especie , Relación Estructura-ActividadRESUMEN
Neonicotinoid insecticides, which target insect nicotinic acetylcholine receptors (nAChRs), have been widely and intensively used to control the whitefly, Bemisia tabaci, a highly damaging, globally distributed, crop pest. This has inevitably led to the emergence of populations with resistance to neonicotinoids. However, to date, there have been no reports of target-site resistance involving mutation of B. tabaci nAChR genes. Here we characterize the nAChR subunit gene family of B. tabaci and identify dual mutations (A58T&R79E) in one of these genes (BTß1) that confer resistance to multiple neonicotinoids. Transgenic D. melanogaster, where the native nAChR Dß1 was replaced with BTß1A58T&R79E, were significantly more resistant to neonicotinoids than flies where Dß1 were replaced with the wildtype BTß1 sequence, demonstrating the causal role of the mutations in resistance. The two mutations identified in this study replace two amino acids that are highly conserved in >200 insect species. Three-dimensional modelling suggests a molecular mechanism for this resistance, whereby A58T forms a hydrogen bond with the R79E side chain, which positions its negatively-charged carboxylate group to electrostatically repulse a neonicotinoid at the orthosteric site. Together these findings describe the first case of target-site resistance to neonicotinoids in B. tabaci and provide insight into the molecular determinants of neonicotinoid binding and selectivity.
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Hemípteros , Insecticidas , Receptores Nicotínicos , Animales , Receptores Nicotínicos/genética , Insecticidas/farmacología , Hemípteros/genética , Drosophila melanogaster , Neonicotinoides/farmacología , MutaciónRESUMEN
Cardiometabolic diseases (CMDs) are major contributors to global mortality, emphasizing the critical need for novel therapeutic interventions. Hydrogen sulfide (H2S) has garnered enormous attention as a significant gasotransmitter with various physiological, pathophysiological, and pharmacological impacts within mammalian cardiometabolic systems. In addition to its roles in attenuating oxidative stress and inflammatory response, burgeoning research emphasizes the significance of H2S in regulating proteins via persulfidation, a well known modification intricately associated with the pathogenesis of CMDs. This review seeks to investigate recent updates on the physiological actions of endogenous H2S and the pharmacological roles of various H2S donors in addressing diverse aspects of CMDs across cellular, animal, and clinical studies. Of note, advanced methodologies, including multiomics, intestinal microflora analysis, organoid, and single-cell sequencing techniques, are gaining traction due to their ability to offer comprehensive insights into biomedical research. These emerging approaches hold promise in characterizing the pharmacological roles of H2S in health and diseases. We will critically assess the current literature to clarify the roles of H2S in diseases while also delineating the opportunities and challenges they present in H2S-based pharmacotherapy for CMDs. SIGNIFICANCE STATEMENT: This comprehensive review covers recent developments in H2S biology and pharmacology in cardiometabolic diseases CMDs. Endogenous H2S and its donors show great promise for the management of CMDs by regulating numerous proteins and signaling pathways. The emergence of new technologies will considerably advance the pharmacological research and clinical translation of H2S.
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Enfermedades Cardiovasculares , Sulfuro de Hidrógeno , Sulfuro de Hidrógeno/metabolismo , Humanos , Animales , Enfermedades Cardiovasculares/tratamiento farmacológico , Enfermedades Cardiovasculares/metabolismo , Enfermedades Metabólicas/tratamiento farmacológico , Enfermedades Metabólicas/metabolismo , Gasotransmisores/metabolismoRESUMEN
The field of synthetic biology and biosystems engineering increasingly acknowledges the need for a holistic design approach that incorporates circuit-host interactions into the design process. Engineered circuits are not isolated entities but inherently entwined with the dynamic host environment. One such circuit-host interaction, 'growth feedback', results when modifications in host growth patterns influence the operation of gene circuits. The growth-mediated effects can range from growth-dependent elevation in protein/mRNA dilution rate to changes in resource reallocation within the cell, which can lead to complete functional collapse in complex circuits. To achieve robust circuit performance, synthetic biologists employ a variety of control mechanisms to stabilize and insulate circuit behavior against growth changes. Here we propose a simple strategy by incorporating one repressive edge in a growth-sensitive bistable circuit. Through both simulation and in vitro experimentation, we demonstrate how this additional repressive node stabilizes protein levels and increases the robustness of a bistable circuit in response to growth feedback. We propose the incorporation of repressive links in gene circuits as a control strategy for desensitizing gene circuits against growth fluctuations.
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Redes Reguladoras de Genes , Biología Sintética , Simulación por Computador , Retroalimentación , Proteínas/genética , Biología Sintética/métodosRESUMEN
AMPA receptors (AMPARs) play a critical role in synaptic plasticity and learning and memory, and dysfunction or dysregulation of AMPARs could lead to various neurological and psychiatric disorders, such as Alzheimer's disease (AD). However, the dynamics and/or longitudinal changes of AMPARs in vivo during AD pathogenesis remain elusive. Here, employing 5xFAD SEP-GluA1 KI mice, we investigated endogenous AMPA receptor dynamics in a whisker deflection-associated Go/No-go learning paradigm. We found a significant increase in synaptosomal AMPA receptor subunits GluA1 in WT mice after learning, while no such changes were detected in 7-mo-old 5xFAD mice. Daily training led to an increase in endogenous spine surface GluA1 in Control mice, while this increase was absent in 5xFAD-KI mice which correlates with its learning defects in Go/No-go paradigm. Furthermore, we demonstrated that the onset of abnormal AMPAR dynamics corresponds temporally with microglia and astrocyte overactivation. Our results have shown that impairments in endogenous AMPA receptor dynamics play an important role in learning deficits in 5xFAD mice and AD pathogenesis.
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Enfermedad de Alzheimer , Receptores AMPA , Humanos , Animales , Ratones , Aprendizaje , Astrocitos , MicroglíaRESUMEN
Currently, monoclonal antibodies (MAbs) targeting the SARS-CoV-2 receptor binding domain (RBD) of spike (S) protein are classified into seven classes based on their binding epitopes. However, most of these antibodies are seriously impaired by SARS-CoV-2 Omicron and its subvariants, especially the recent BQ.1.1, XBB and its derivatives. Identification of broadly neutralizing MAbs against currently circulating variants is imperative. In this study, we identified a "breathing" cryptic epitope in the S protein, named as RBD-8. Two human MAbs, BIOLS56 and IMCAS74, were isolated recognizing this epitope with broad neutralization abilities against tested sarbecoviruses, including SARS-CoV, pangolin-origin coronaviruses, and all the SARS-CoV-2 variants tested (Omicron BA.4/BA.5, BQ.1.1, and XBB subvariants). Searching through the literature, some more RBD-8 MAbs were defined. More importantly, BIOLS56 rescues the immune-evaded antibody, RBD-5 MAb IMCAS-L4.65, by making a bispecific MAb, to neutralize BQ.1 and BQ.1.1, thereby producing an MAb to cover all the currently circulating Omicron subvariants. Structural analysis reveals that the neutralization effect of RBD-8 antibodies depends on the extent of epitope exposure, which is affected by the angle of antibody binding and the number of up-RBDs induced by angiotensin-converting enzyme 2 binding. This cryptic epitope which recognizes non- receptor binding motif (non-RBM) provides guidance for the development of universal therapeutic antibodies and vaccines against COVID-19.
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COVID-19 , SARS-CoV-2 , Humanos , Vacunas contra la COVID-19 , Anticuerpos Monoclonales , Epítopos , Anticuerpos Neutralizantes , Anticuerpos Antivirales , Glicoproteína de la Espiga del CoronavirusRESUMEN
Cryptotaenia japonica, a traditional medicinal and edible vegetable crops, is well-known for its attractive flavors and health care functions. As a member of the Apiaceae family, the evolutionary trajectory and biological properties of C. japonica are not clearly understood. Here, we first reported a high-quality genome of C. japonica with a total length of 427 Mb and N50 length 50.76 Mb, was anchored into 10 chromosomes, which confirmed by chromosome (cytogenetic) analysis. Comparative genomic analysis revealed C. japonica exhibited low genetic redundancy, contained a higher percentage of single-cope gene families. The homoeologous blocks, Ks, and collinearity were analyzed among Apiaceae species contributed to the evidence that C. japonica lacked recent species-specific WGD. Through comparative genomic and transcriptomic analyses of Apiaceae species, we revealed the genetic basis of the production of anthocyanins. Several structural genes encoding enzymes and transcription factor genes of the anthocyanin biosynthesis pathway in different species were also identified. The CjANSa, CjDFRb, and CjF3H gene might be the target of Cjaponica_2.2062 (bHLH) and Cjaponica_1.3743 (MYB). Our findings provided a high-quality reference genome of C. japonica and offered new insights into Apiaceae evolution and biology.
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Antocianinas , Apiaceae , Genoma de Planta , Genómica , Antocianinas/biosíntesis , Antocianinas/genética , Antocianinas/metabolismo , Genoma de Planta/genética , Apiaceae/genética , Apiaceae/metabolismo , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Regulación de la Expresión Génica de las Plantas , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Cromosomas de las Plantas/genéticaRESUMEN
Impairments in social relationships and awareness are features observed in autism spectrum disorders (ASDs). However, the underlying mechanisms remain poorly understood. Shank2 is a high-confidence ASD candidate gene and localizes primarily to postsynaptic densities (PSDs) of excitatory synapses in the central nervous system (CNS). We show here that loss of Shank2 in mice leads to a lack of social attachment and bonding behavior towards pubs independent of hormonal, cognitive, or sensitive deficits. Shank2-/- mice display functional changes in nuclei of the social attachment circuit that were most prominent in the medial preoptic area (MPOA) of the hypothalamus. Selective enhancement of MPOA activity by DREADD technology re-established social bonding behavior in Shank2-/- mice, providing evidence that the identified circuit might be crucial for explaining how social deficits in ASD can arise.
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Trastorno Autístico/tratamiento farmacológico , Modelos Animales de Enfermedad , Relaciones Interpersonales , Conducta Materna/efectos de los fármacos , Proteínas del Tejido Nervioso/fisiología , Piperazinas/farmacología , Área Preóptica/efectos de los fármacos , Animales , Trastorno Autístico/etiología , Trastorno Autístico/metabolismo , Trastorno Autístico/patología , Femenino , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Área Preóptica/metabolismo , Área Preóptica/patología , SinapsisRESUMEN
Zoonotic coronaviruses pose a continuous threat to human health, with newly identified bat-borne viruses like swine acute diarrhea syndrome coronavirus (SADS-CoV) causing high mortality in piglets. In vitro studies indicate that SADS-CoV can infect cell lines from diverse species, including humans, highlighting its potential risk to human health. However, the lack of tools to study viral entry, along with the absence of vaccines or antiviral therapies, perpetuates this threat. To address this, we engineered an infectious molecular clone of Vesicular Stomatitis Virus (VSV), replacing its native glycoprotein (G) with SADS-CoV spike (S) and inserting a Venus reporter at the 3' leader region to generate a replication-competent rVSV-Venus-SADS S virus. Serial passages of rVSV-Venus-SADS S led to the identification of an 11-amino-acid truncation in the cytoplasmic tail of the S protein, which allowed more efficient viral propagation due to increased cell membrane anchoring of the S protein. The S protein was integrated into rVSV-Venus-SADS SΔ11 particles, susceptible to neutralization by sera from SADS-CoV S1 protein-immunized rabbits. Additionally, we found that TMPRSS2 promotes SADS-CoV spike-mediated cell entry. Furthermore, we assessed the serum-neutralizing ability of mice vaccinated with rVSV-Venus-SADS SΔ11 using a prime-boost immunization strategy, revealing effective neutralizing antibodies against SADS-CoV infection. In conclusion, we have developed a safe and practical tool for studying SADS-CoV entry and exploring the potential of a recombinant VSV-vectored SADS-CoV vaccine.IMPORTANCEZoonotic coronaviruses, like swine acute diarrhea syndrome coronavirus (SADS-CoV), pose a continual threat to human and animal health. To combat this, we engineered a safe and efficient tool by modifying the Vesicular Stomatitis Virus (VSV), creating a replication-competent rVSV-Venus-SADS S virus. Through serial passages, we optimized the virus for enhanced membrane anchoring, a key factor in viral propagation. This modified virus, rVSV-Venus-SADS SΔ11, proved susceptible to neutralization, opening avenues for potential vaccines. Additionally, our study revealed the role of TMPRSS2 in SADS-CoV entry. Mice vaccinated with rVSV-Venus-SADS SΔ11 developed potent neutralizing antibodies against SADS-CoV. In conclusion, our work presents a secure and practical tool for studying SADS-CoV entry and explores the promise of a recombinant VSV-vectored SADS-CoV vaccine.
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Alphacoronavirus , Internalización del Virus , Replicación Viral , Animales , Humanos , Ratones , Conejos , Alphacoronavirus/genética , Enzima Convertidora de Angiotensina 2/metabolismo , Enzima Convertidora de Angiotensina 2/genética , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Línea Celular , Chlorocebus aethiops , Infecciones por Coronavirus/virología , Infecciones por Coronavirus/prevención & control , Células HEK293 , Serina Endopeptidasas/genética , Serina Endopeptidasas/metabolismo , Serina Endopeptidasas/inmunología , Glicoproteína de la Espiga del Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/inmunología , Glicoproteína de la Espiga del Coronavirus/metabolismo , Porcinos , Células Vero , Virus de la Estomatitis Vesicular Indiana/genética , Vesiculovirus/genética , Vacunas Virales/inmunología , Vacunas Virales/genéticaRESUMEN
During the life cycle of mosquito-borne flaviviruses, substantial subgenomic flaviviral RNA (sfRNA) is produced via incomplete degradation of viral genomic RNA by host XRN1. Zika virus (ZIKV) sfRNA has been detected in mosquito and mammalian somatic cells. Human neural progenitor cells (hNPCs) in the developing brain are the major target cells of ZIKV, and antiviral RNA interference (RNAi) plays a critical role in hNPCs. However, whether ZIKV sfRNA was produced in ZIKV-infected hNPCs as well as its function remains not known. In this study, we demonstrate that abundant sfRNA was produced in ZIKV-infected hNPCs. RNA pulldown and mass spectrum assays showed ZIKV sfRNA interacted with host proteins RHA and PACT, both of which are RNA-induced silencing complex (RISC) components. Functionally, ZIKV sfRNA can antagonize RNAi by outcompeting small interfering RNAs (siRNAs) in binding to RHA and PACT. Furthermore, the 3' stem loop (3'SL) of sfRNA was responsible for RISC components binding and RNAi inhibition, and 3'SL can enhance the replication of a viral suppressor of RNAi (VSR)-deficient virus in a RHA- and PACT-dependent manner. More importantly, the ability of binding to RISC components is conversed among multiple flaviviral 3'SLs. Together, our results identified flavivirus 3'SL as a potent VSR in RNA format, highlighting the complexity in virus-host interaction during flavivirus infection.IMPORTANCEZika virus (ZIKV) infection mainly targets human neural progenitor cells (hNPCs) and induces cell death and dysregulated cell-cycle progression, leading to microcephaly and other central nervous system abnormalities. RNA interference (RNAi) plays critical roles during ZIKV infections in hNPCs, and ZIKV has evolved to encode specific viral proteins to antagonize RNAi. Herein, we first show that abundant sfRNA was produced in ZIKV-infected hNPCs in a similar pattern to that in other cells. Importantly, ZIKV sfRNA acts as a potent viral suppressor of RNAi (VSR) by competing with siRNAs for binding RISC components, RHA and PACT. The 3'SL of sfRNA is responsible for binding RISC components, which is a conserved feature among mosquito-borne flaviviruses. As most known VSRs are viral proteins, our findings highlight the importance of viral non-coding RNAs during the antagonism of host RNAi-based antiviral innate immunity.
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Infección por el Virus Zika , Virus Zika , Animales , Humanos , Mamíferos/genética , Interferencia de ARN , ARN Interferente Pequeño/genética , ARN Viral/genética , ARN Viral/metabolismo , Complejo Silenciador Inducido por ARN/metabolismo , ARN Subgenómico , Proteínas Virales/metabolismo , Replicación Viral , Virus Zika/fisiología , Infección por el Virus Zika/inmunología , Infección por el Virus Zika/virologíaRESUMEN
Symmetry breaking in quantum materials is of great importance and can lead to non-reciprocal charge transport. Topological insulators provide a unique platform to study non-reciprocal charge transport due to their surface states, especially quantum Hall states under an external magnetic field. Here we report the observation of non-reciprocal charge transport mediated by quantum Hall states in devices composed of the intrinsic topological insulator Sn-Bi1.1Sb0.9Te2S, which is attributed to asymmetric scattering between quantum Hall states and Dirac surface states. A giant non-reciprocal coefficient of up to 2.26 × 105 A-1 is found. Our work not only reveals the properties of non-reciprocal charge transport of quantum Hall states in topological insulators but also paves the way for future electronic devices.
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BACKGROUND AND AIMS: An imbalance in lipid metabolism is the main cause of NAFLD. While the pathogenesis of lipid accumulation mediated by extrahepatic regulators has been extensively studied, the intrahepatic regulators modulating lipid homeostasis remain unclear. Previous studies have shown that systemic administration of IL-22 protects against NAFLD; however, the role of IL-22/IL22RA1 signaling in modulating hepatic lipid metabolism remains uncertain. APPROACH AND RESULTS: This study shows that hepatic IL22RA1 is vital in hepatic lipid regulation. IL22RA1 is downregulated in palmitic acid-treated mouse primary hepatocytes, as well as in the livers of NAFLD model mice and patients. Hepatocyte-specific Il22ra1 knockout mice display diet-induced hepatic steatosis, insulin resistance, impaired glucose tolerance, increased inflammation, and fibrosis compared with flox/flox mice. This is attributed to increased lipogenesis mediated by the accumulation of hepatic oxysterols, particularly 3 beta-hydroxy-5-cholestenoic acid (3ß HCA). Mechanistically, hepatic IL22RA1 deficiency facilitates 3ß HCA deposition through the activating transcription factor 3/oxysterol 7 alpha-hydroxylase axis. Notably, 3ß HCA facilitates lipogenesis in mouse primary hepatocytes and human liver organoids by activating liver X receptor-alpha signaling, but IL-22 treatment attenuates this effect. Additionally, restoring oxysterol 7 alpha-hydroxylase or silencing hepatic activating transcription factor 3 reduces both hepatic 3ß HCA and lipid contents in hepatocyte-specific Il22ra1 knockout mice. CONCLUSIONS: These findings indicate that IL22RA1 plays a crucial role in maintaining hepatic lipid homeostasis in an activating transcription factor 3/oxysterol 7 alpha-hydroxylase-dependent manner and establish a link between 3ß HCA and hepatic lipid homeostasis.
RESUMEN
Mastitis is a disease characterized by congestion, swelling, and inflammation of the mammary gland and usually caused by infection with pathogenic microorganisms. Furthermore, the development of mastitis is closely linked to the exogenous pathway of the gastrointestinal tract. However, the regulatory mechanisms governing the gut-metabolism-mammary axis remain incompletely understood. The present study revealed alterations in the gut microbiota of mastitis rats characterized by an increased abundance of the Proteobacteria phylum. Plasma analysis revealed significantly higher levels of L-isoleucine and cholic acid along with 7-ketodeoxycholic acid. Mammary tissue showed elevated levels of arachidonic acid metabolites and norlithocholic acid. Proteomic analysis showed increased levels of IFIH1, Tnfaip8l2, IRGM, and IRF5 in mastitis rats, which suggests that mastitis triggers an inflammatory response and immune stress. Follistatin (Fst) and progesterone receptor (Pgr) were significantly downregulated, raising the risk of breast cancer. Extracellular matrix (ECM) receptors and focal adhesion signaling pathways were downregulated, while blood-milk barrier integrity was disrupted. Analysis of protein-metabolic network regulation revealed that necroptosis, protein digestion and absorption, and arachidonic acid metabolism were the principal regulatory pathways involved in the development of mastitis. In short, the onset of mastitis leads to changes in the microbiota and alterations in the metabolic profiles of various biological samples, including colonic contents, plasma, and mammary tissue. Key manifestations include disturbances in bile acid metabolism, amino acid metabolism, and arachidonic acid metabolism. At the same time, the integrity of the blood-milk barrier is compromised while inflammation is promoted, thereby reducing cell adhesion in the mammary glands. These findings contribute to a more comprehensive understanding of the metabolic status of mastitis and provide new insights into its impact on the immune system.
Asunto(s)
Mastitis , Infecciones Estafilocócicas , Femenino , Humanos , Ratas , Animales , Staphylococcus aureus/fisiología , Proteómica , Ácido Araquidónico/metabolismo , Mastitis/microbiología , Mastitis/patología , Mastitis/veterinaria , Inflamación/metabolismo , Redes y Vías Metabólicas , Glándulas Mamarias Animales/metabolismo , Infecciones Estafilocócicas/metabolismoRESUMEN
Delay discounting refers to the tendency of individuals to devalue future rewards as the delay in their receipt increases over time. Previous studies have indicated that future self-continuity correlates with delay discounting rates. However, the neural basis underlying the relationship between future self-continuity and delay discounting is not clear. To address this question, we used voxel-based morphometry and resting-state functional connectivity analyses to investigate the neural basis underlying the association between future self-continuity and delay discounting. Behavioral result showed that future self-continuity was positively associated with delay discounting. Voxel-based morphometry analysis result indicated that gray matter volume in the right dorsal anterior insula was positively correlated with future self-continuity. Resting-state functional connectivity analysis found that functional connectivity between the right dorsal anterior insula and anterior cingulate cortex was positively associated with future self-continuity. Mediation analysis showed that the right dorsal anterior insula-right anterior cingulate cortex functional connectivity partially mediated the relationship between future self-continuity and delay discounting. These results suggested that right dorsal anterior insula-right anterior cingulate cortex functional connectivity could be the neural basis underlying the association between future self-continuity and delay discounting. In summary, the study provided novel insights into how future self-continuity affected delay discounting and offers new explanations from a neural perspective.