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1.
Cell ; 186(21): 4615-4631.e16, 2023 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-37769658

RESUMO

SARS-CoV-2 primary strain-based vaccination exerts a protective effect against Omicron variants-initiated infection, symptom occurrence, and disease severity in a booster-dependent manner. Yet, the underlying mechanisms remain unclear. During the 2022 Omicron outbreak in Shanghai, we enrolled 122 infected adults and 50 uninfected controls who had been unvaccinated or vaccinated with two or three doses of COVID-19 inactive vaccines and performed integrative analysis of 41-plex CyTOF, RNA-seq, and Olink on their peripheral blood samples. The frequencies of HLA-DRhi classical monocytes, non-classical monocytes, and Th1-like Tem tended to increase, whereas the frequency of Treg was reduced by booster vaccine, and they influenced symptom occurrence in a vaccine dose-dependent manner. Intercorrelation and mechanistic analysis suggested that the booster vaccination induced monocytic training, which would prime monocytic activation and maturation rather than differentiating into myeloid-derived suppressive cells upon Omicron infections. Overall, our study provides insights into how booster vaccination elaborates protective immunity across SARS-CoV-2 variants.

2.
Immunity ; 54(4): 781-796.e4, 2021 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-33675683

RESUMO

Human IGHV1-69-encoded broadly neutralizing antibodies (bnAbs) that target the hepatitis C virus (HCV) envelope glycoprotein (Env) E2 are important for protection against HCV infection. An IGHV1-69 ortholog gene, VH1.36, is preferentially used for bnAbs isolated from HCV Env-immunized rhesus macaques (RMs). Here, we studied the genetic, structural, and functional properties of VH1.36-encoded bnAbs generated by vaccination, in comparison to IGHV1-69-encoded bnAbs from HCV patients. Global B cell repertoire analysis confirmed the expansion of VH1.36-derived B cells in immunized animals. Most E2-specific, VH1.36-encoded antibodies cross-neutralized HCV. Crystal structures of two RM bnAbs with E2 revealed that the RM bnAbs engaged conserved E2 epitopes using similar molecular features as human bnAbs but with a different binding mode. Longitudinal analyses of the RM antibody repertoire responses during immunization indicated rapid lineage development of VH1.36-encoded bnAbs with limited somatic hypermutation. Our findings suggest functional convergence of a germline-encoded bnAb response to HCV Env with implications for vaccination in humans.


Assuntos
Anticorpos Neutralizantes/imunologia , Células Germinativas/imunologia , Glicoproteínas/imunologia , Hepacivirus/imunologia , Hepatite C/imunologia , Macaca mulatta/imunologia , Proteínas do Envelope Viral/imunologia , Animais , Linfócitos B/imunologia , Células CHO , Linhagem Celular , Cricetulus , Epitopos/imunologia , Células HEK293 , Hepatite C/virologia , Humanos , Estudos Longitudinais , Macaca mulatta/virologia , Receptores de Antígenos de Linfócitos B/imunologia , Vacinação/métodos
3.
Cell ; 152(3): 642-54, 2013 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-23333102

RESUMO

Differences in chromatin organization are key to the multiplicity of cell states that arise from a single genetic background, yet the landscapes of in vivo tissues remain largely uncharted. Here, we mapped chromatin genome-wide in a large and diverse collection of human tissues and stem cells. The maps yield unprecedented annotations of functional genomic elements and their regulation across developmental stages, lineages, and cellular environments. They also reveal global features of the epigenome, related to nuclear architecture, that also vary across cellular phenotypes. Specifically, developmental specification is accompanied by progressive chromatin restriction as the default state transitions from dynamic remodeling to generalized compaction. Exposure to serum in vitro triggers a distinct transition that involves de novo establishment of domains with features of constitutive heterochromatin. We describe how these global chromatin state transitions relate to chromosome and nuclear architecture, and discuss their implications for lineage fidelity, cellular senescence, and reprogramming.


Assuntos
Montagem e Desmontagem da Cromatina , Cromatina/metabolismo , Epigênese Genética , Interação Gene-Ambiente , Estudo de Associação Genômica Ampla , Núcleo Celular , Senescência Celular , Células-Tronco Embrionárias/metabolismo , Regulação da Expressão Gênica , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Especificidade de Órgãos
4.
Mol Cell ; 78(5): 903-914.e4, 2020 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-32396821

RESUMO

LSD1 (lysine specific demethylase; also known as KDM1A), the first histone demethylase discovered, regulates cell-fate determination and is overexpressed in multiple cancers. LSD1 demethylates histone H3 Lys4, an epigenetic mark for active genes, but requires the CoREST repressor to act on nucleosome substrates. To understand how an accessory subunit (CoREST) enables a chromatin enzyme (LSD1) to function on a nucleosome and not just histones, we have determined the crystal structure of the LSD1/CoREST complex bound to a 191-bp nucleosome. We find that the LSD1 catalytic domain binds extranucleosomal DNA and is unexpectedly positioned 100 Å away from the nucleosome core. CoREST makes critical contacts with both histone and DNA components of the nucleosome, explaining its essential function in demethylating nucleosome substrates. Our studies also show that the LSD1(K661A) frequently used as a catalytically inactive mutant in vivo (based on in vitro peptide studies) actually retains substantial H3K4 demethylase activity on nucleosome substrates.


Assuntos
Histona Desmetilases/metabolismo , Histona Desmetilases/ultraestrutura , Sequência de Aminoácidos , Domínio Catalítico , Cromatina/metabolismo , Proteínas Correpressoras/genética , Proteínas Correpressoras/metabolismo , Cristalografia por Raios X/métodos , DNA/genética , DNA/metabolismo , Histona Desmetilases/genética , Histonas/metabolismo , Humanos , Metilação , Modelos Moleculares , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Nucleossomos/química , Nucleossomos/genética , Nucleossomos/metabolismo , Peptídeos/metabolismo , Ligação Proteica , Conformação Proteica
5.
Nature ; 599(7884): 239-244, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34759364

RESUMO

Climate changes across the past 24,000 years provide key insights into Earth system responses to external forcing. Climate model simulations1,2 and proxy data3-8 have independently allowed for study of this crucial interval; however, they have at times yielded disparate conclusions. Here, we leverage both types of information using paleoclimate data assimilation9,10 to produce the first proxy-constrained, full-field reanalysis of surface temperature change spanning the Last Glacial Maximum to present at 200-year resolution. We demonstrate that temperature variability across the past 24 thousand years was linked to two primary climatic mechanisms: radiative forcing from ice sheets and greenhouse gases; and a superposition of changes in the ocean overturning circulation and seasonal insolation. In contrast with previous proxy-based reconstructions6,7 our results show that global mean temperature has slightly but steadily warmed, by ~0.5 °C, since the early Holocene (around 9 thousand years ago). When compared with recent temperature changes11, our reanalysis indicates that both the rate and magnitude of modern warming are unusual relative to the changes of the past 24 thousand years.


Assuntos
Modelos Climáticos , Mapeamento Geográfico , Aquecimento Global/história , Gases de Efeito Estufa/história , Camada de Gelo , Água do Mar/análise , Temperatura , História Antiga , Reprodutibilidade dos Testes , Estações do Ano , Movimentos da Água
6.
Proc Natl Acad Sci U S A ; 121(4): e2315401121, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38232280

RESUMO

Biomacromolecular folding kinetics involves fast folding events and broad timescales. Current techniques face limitations in either the required time resolution or the observation window. In this study, we developed the TeZla micromixer, integrating Tesla and Zigzag microstructures with a multistage velocity descending strategy. TeZla achieves a significant short mixing dead time (40 µs) and a wide time window covering four orders of magnitude (up to 300 ms). Using this unique micromixer, we explored the folding landscape of c-Myc G4 and its noncanonical-G4 derivatives with different loop lengths or G-vacancy sites. Our findings revealed that c-Myc can bypass folding intermediates and directly adopt a G4 structure in the cation-deficient buffer. Moreover, we found that the loop length and specific G-vacancy site could affect the folding pathway and significantly slow down the folding rates. These results were also cross-validated with real-time NMR and circular dichroism. In conclusion, TeZla represents a versatile tool for studying biomolecular folding kinetics, and our findings may ultimately contribute to the design of drugs targeting G4 structures.


Assuntos
Quadruplex G , Cinética , Física
7.
Nature ; 584(7822): 569-573, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32848226

RESUMO

The Last Glacial Maximum (LGM), one of the best studied palaeoclimatic intervals, offers an excellent opportunity to investigate how the climate system responds to changes in greenhouse gases and the cryosphere. Previous work has sought to constrain the magnitude and pattern of glacial cooling from palaeothermometers1,2, but the uneven distribution of the proxies, as well as their uncertainties, has challenged the construction of a full-field view of the LGM climate state. Here we combine a large collection of geochemical proxies for sea surface temperature with an isotope-enabled climate model ensemble to produce a field reconstruction of LGM temperatures using data assimilation. The reconstruction is validated with withheld proxies as well as independent ice core and speleothem δ18O measurements. Our assimilated product provides a constraint on global mean LGM cooling of -6.1 degrees Celsius (95 per cent confidence interval: -6.5 to -5.7 degrees Celsius). Given assumptions concerning the radiative forcing of greenhouse gases, ice sheets and mineral dust aerosols, this cooling translates to an equilibrium climate sensitivity of 3.4 degrees Celsius (2.4-4.5 degrees Celsius), a value that is higher than previous LGM-based estimates but consistent with the traditional consensus range of 2-4.5 degrees Celsius3,4.

8.
Immunity ; 45(1): 31-45, 2016 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-27438765

RESUMO

The dense patch of high-mannose-type glycans surrounding the N332 glycan on the HIV envelope glycoprotein (Env) is targeted by multiple broadly neutralizing antibodies (bnAbs). This region is relatively conserved, implying functional importance, the origins of which are not well understood. Here we describe the isolation of new bnAbs targeting this region. Examination of these and previously described antibodies to Env revealed that four different bnAb families targeted the (324)GDIR(327) peptide stretch at the base of the gp120 V3 loop and its nearby glycans. We found that this peptide stretch constitutes part of the CCR5 co-receptor binding site, with the high-mannose patch glycans serving to camouflage it from most antibodies. GDIR-glycan bnAbs, in contrast, bound both (324)GDIR(327) peptide residues and high-mannose patch glycans, which enabled broad reactivity against diverse HIV isolates. Thus, as for the CD4 binding site, bnAb effectiveness relies on circumventing the defenses of a critical functional region on Env.


Assuntos
Anticorpos Neutralizantes/imunologia , Sítios de Ligação de Anticorpos/imunologia , Anticorpos Anti-HIV/imunologia , Proteína gp120 do Envelope de HIV/metabolismo , Infecções por HIV/imunologia , HIV-1/imunologia , Polissacarídeos/metabolismo , Motivos de Aminoácidos , Antígenos CD4/metabolismo , Mapeamento de Epitopos , Epitopos/metabolismo , Engenharia Genética , Células HEK293 , Proteína gp120 do Envelope de HIV/imunologia , Humanos , Imunidade Humoral , Memória Imunológica , Fragmentos de Peptídeos/metabolismo , Polissacarídeos/imunologia , Ligação Proteica , Receptores CCR5/metabolismo
9.
Immunity ; 44(4): 939-50, 2016 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-27067056

RESUMO

VRC01-class antibodies neutralize diverse HIV-1 strains by targeting the conserved CD4-binding site. Despite extensive investigations, crucial events in the early stage of VRC01 development remain elusive. We demonstrated how VRC01-class antibodies emerged in a Chinese donor by antigen-specific single B cell sorting, structural and functional studies, and longitudinal antibody and virus repertoire analyses. A monoclonal antibody DRVIA7 with modest neutralizing breadth was isolated that displayed a subset of VRC01 signatures. X-ray and EM structures revealed a VRC01-like angle of approach, but less favorable interactions between the DRVIA7 light-chain CDR1 and the N terminus with N276 and V5 glycans of gp120. Although the DRVIA7 lineage was unable to acquire broad neutralization, longitudinal analysis revealed a repertoire-encoded VRC01 light-chain CDR3 signature and VRC01-like neutralizing heavy-chain precursors that rapidly matured within 2 years. Thus, light chain accommodation of the glycan shield should be taken into account in vaccine design targeting this conserved site of vulnerability.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Sítios de Ligação de Anticorpos/imunologia , Anticorpos Anti-HIV/imunologia , Proteína gp120 do Envelope de HIV/imunologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia , Sequência de Aminoácidos , Anticorpos Amplamente Neutralizantes , Linfócitos T CD4-Positivos/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Humanos , Dados de Sequência Molecular
10.
Mol Cell Proteomics ; 22(8): 100604, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37353004

RESUMO

Liver cancer is among the top leading causes of cancer mortality worldwide. Particularly, hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (CCA) have been extensively investigated from the aspect of tumor biology. However, a comprehensive and systematic understanding of the molecular characteristics of HCC and CCA remains absent. Here, we characterized the proteome landscapes of HCC and CCA using the data-independent acquisition (DIA) mass spectrometry (MS) method. By comparing the quantitative proteomes of HCC and CCA, we found several differences between the two cancer types. In particular, we found an abnormal lipid metabolism in HCC and activated extracellular matrix-related pathways in CCA. We next developed a three-protein classifier to distinguish CCA from HCC, achieving an area under the curve (AUC) of 0.92, and an accuracy of 90% in an independent validation cohort of 51 patients. The distinct molecular characteristics of HCC and CCA presented in this study provide new insights into the tumor biology of these two major important primary liver cancers. Our findings may help develop more efficient diagnostic approaches and new targeted drug treatments.


Assuntos
Neoplasias dos Ductos Biliares , Carcinoma Hepatocelular , Colangiocarcinoma , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Proteoma , Ductos Biliares Intra-Hepáticos/metabolismo , Ductos Biliares Intra-Hepáticos/patologia , Neoplasias dos Ductos Biliares/diagnóstico , Neoplasias dos Ductos Biliares/metabolismo , Neoplasias dos Ductos Biliares/patologia , Estudos Retrospectivos
11.
Nucleic Acids Res ; 51(2): 619-630, 2023 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-36546827

RESUMO

Jasmonic acid (JA) signaling plays a pivotal role in plant development and defense. MYC2 is a master transcription factor in JA signaling, and was found to be phosphorylated and negatively regulated by MAP kinase and receptor-like kinase. However, the kinases that positively regulate MYC2 through phosphorylation and promote MYC2-mediated activation of JA response have not been identified. Here, we identified CK2 as a kinase that phosphorylates MYC2 and thus regulates the JA signaling. CK2 holoenzyme can interact with MYC2 using its regulatory subunits and phosphorylate MYC2 at multiple sites with its catalytic subunits. Inhibition of CK2 activity in a dominant-negative plant line, CK2mut, repressed JA response. On the other hand, increasing CK2 activity by overexpression of CKB4, a regulatory subunit gene of CK2, enhanced JA response in a MYC2-dependent manner. Substitution of the Ser and Thr residues at phosphorylation sites of MYC2 by CK2 with Ala impaired MYC2 function in activating JA response. Further investigations evidenced that CK2 facilitated the JA-induced increase of MYC2 binding to the promoters of JA-responsive genes in vivo. Our study demonstrated that CK2 plays a positive role in JA signaling, and reveals a previously undiscovered mechanism that regulates MYC2 function.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos , Caseína Quinase II , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Ciclopentanos/metabolismo , Regulação da Expressão Gênica de Plantas , Fosfotransferases/genética , Caseína Quinase II/metabolismo
12.
Nucleic Acids Res ; 51(D1): D88-D100, 2023 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-36318256

RESUMO

Chromatin regulators (CRs) regulate epigenetic patterns on a partial or global scale, playing a critical role in affecting multi-target gene expression. As chromatin immunoprecipitation sequencing (ChIP-seq) data associated with CRs are rapidly accumulating, a comprehensive resource of CRs needs to be built urgently for collecting, integrating, and processing these data, which can provide abundant annotated information on CR upstream and downstream regulatory analyses as well as CR-related analysis functions. This study established an integrative CR resource, named CRdb (http://cr.liclab.net/crdb/), with the aim of curating a large number of available resources for CRs and providing extensive annotations and analyses of CRs to help biological researchers clarify the regulation mechanism and function of CRs. The CRdb database comprised a total of 647 CRs and 2,591 ChIP-seq samples from more than 300 human tissues and cell types. These samples have been manually curated from NCBI GEO/SRA and ENCODE. Importantly, CRdb provided the abundant and detailed genetic annotations in CR-binding regions based on ChIP-seq. Furthermore, CRdb supported various functional annotations and upstream regulatory information on CRs. In particular, it embedded four types of CR regulatory analyses: CR gene set enrichment, CR-binding genomic region annotation, CR-TF co-occupancy analysis, and CR regulatory axis analysis. CRdb is a useful and powerful resource that can help in exploring the potential functions of CRs and their regulatory mechanism in diseases and biological processes.


Assuntos
Cromatina , Bases de Dados Genéticas , Genômica , Humanos , Cromatina/genética , Bases de Dados Factuais , Genoma , Anotação de Sequência Molecular
13.
Nucleic Acids Res ; 51(D1): D280-D290, 2023 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-36318264

RESUMO

Super-enhancers (SEs) are cell-specific DNA cis-regulatory elements that can supervise the transcriptional regulation processes of downstream genes. SEdb 2.0 (http://www.licpathway.net/sedb) aims to provide a comprehensive SE resource and annotate their potential roles in gene transcriptions. Compared with SEdb 1.0, we have made the following improvements: (i) Newly added the mouse SEs and expanded the scale of human SEs. SEdb 2.0 contained 1 167 518 SEs from 1739 human H3K27ac chromatin immunoprecipitation sequencing (ChIP-seq) samples and 550 226 SEs from 931 mouse H3K27ac ChIP-seq samples, which was five times that of SEdb 1.0. (ii) Newly added transcription factor binding sites (TFBSs) in SEs identified by TF motifs and TF ChIP-seq data. (iii) Added comprehensive (epi)genetic annotations of SEs, including chromatin accessibility regions, methylation sites, chromatin interaction regions and topologically associating domains (TADs). (iv) Newly embedded and updated search and analysis tools, including 'Search SE by TF-based', 'Differential-Overlapping-SE analysis' and 'SE-based TF-Gene analysis'. (v) Newly provided quality control (QC) metrics for ChIP-seq processing. In summary, SEdb 2.0 is a comprehensive update of SEdb 1.0, which curates more SEs and annotation information than SEdb 1.0. SEdb 2.0 provides a friendly platform for researchers to more comprehensively clarify the important role of SEs in the biological process.


Assuntos
Bases de Dados Genéticas , Elementos Facilitadores Genéticos , Animais , Humanos , Camundongos , Cromatina/genética , Regulação da Expressão Gênica , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
14.
Proc Natl Acad Sci U S A ; 119(42): e2205326119, 2022 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-36215472

RESUMO

The Paleocene-Eocene Thermal Maximum (PETM; 56 Ma) is one of our best geological analogs for understanding climate dynamics in a "greenhouse" world. However, proxy data representing the event are only available from select marine and terrestrial sedimentary sequences that are unevenly distributed across Earth's surface, limiting our view of the spatial patterns of climate change. Here, we use paleoclimate data assimilation (DA) to combine climate model and proxy information and create a spatially complete reconstruction of the PETM and the climate state that precedes it ("PETM-DA"). Our data-constrained results support strong polar amplification, which in the absence of an extensive cryosphere, is related to temperature feedbacks and loss of seasonal snow on land. The response of the hydrological cycle to PETM warming consists of a narrowing of the Intertropical Convergence Zone, off-equatorial drying, and an intensification of seasonal monsoons and winter storm tracks. Many of these features are also seen in simulations of future climate change under increasing anthropogenic emissions. Since the PETM-DA yields a spatially complete estimate of surface air temperature, it yields a rigorous estimate of global mean temperature change (5.6 ∘C; 5.4 ∘C to 5.9 ∘C, 95% CI) that can be used to calculate equilibrium climate sensitivity (ECS). We find that PETM ECS was 6.5 ∘C (5.7 ∘C to 7.4 ∘C, 95% CI), which is much higher than the present-day range. This supports the view that climate sensitivity increases substantially when greenhouse gas concentrations are high.


Assuntos
Mudança Climática , Gases de Efeito Estufa , Temperatura
15.
Chembiochem ; 25(7): e202300812, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38351400

RESUMO

Biocatalysis has emerged as a powerful alternative to traditional chemical methods, especially for asymmetric synthesis. As biocatalysts usually exhibit excellent chemical, regio- and enantioselectivity, they facilitate and simplify many chemical processes for the production of a broad range of products. Here, a new biocatalyst called, R-selective amine transaminases (R-ATAs), was obtained from Mycobacterium sp. ACS1612 (M16AT) using in-silico prediction combined with a genome and protein database. A two-step simple purification process could yield a high concentration of pure enzyme, suggesting that industrial application would be inexpensive. Additionally, the newly identified and characterized R-ATAs displayed a broad substrate spectrum and strong tolerance to organic solvents. Moreover, the synthetic applicability of M16AT has been demonstrated by the asymmetric synthesis of (R)-fendiline from of (R)-1-phenylethan-1-amine.


Assuntos
Aminas , Mycobacterium , Aminas/química , Transaminases/metabolismo , Especificidade por Substrato , Biocatálise
16.
Brief Bioinform ; 23(5)2022 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-35959979

RESUMO

The rapid development of genomic high-throughput sequencing has identified a large number of DNA regulatory elements with abundant epigenetics markers, which promotes the rapid accumulation of functional genomic region data. The comprehensively understanding and research of human functional genomic regions is still a relatively urgent work at present. However, the existing analysis tools lack extensive annotation and enrichment analytical abilities for these regions. Here, we designed a novel software, Genomic Region sets Enrichment Analysis Platform (GREAP), which provides comprehensive region annotation and enrichment analysis capabilities. Currently, GREAP supports 85 370 genomic region reference sets, which cover 634 681 107 regions across 11 different data types, including super enhancers, transcription factors, accessible chromatins, etc. GREAP provides widespread annotation and enrichment analysis of genomic regions. To reflect the significance of enrichment analysis, we used the hypergeometric test and also provided a Locus Overlap Analysis. In summary, GREAP is a powerful platform that provides many types of genomic region sets for users and supports genomic region annotations and enrichment analyses. In addition, we developed a customizable genome browser containing >400 000 000 customizable tracks for visualization. The platform is freely available at http://www.liclab.net/Greap/view/index.


Assuntos
Genômica , Software , Cromatina , Genoma Humano , Humanos , Anotação de Sequência Molecular , Fatores de Transcrição
17.
Bioinformatics ; 39(1)2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36477791

RESUMO

MOTIVATION: DNA methylation within gene body and promoters in cancer cells is well documented. An increasing number of studies showed that cytosine-phosphate-guanine (CpG) sites falling within other regulatory elements could also regulate target gene activation, mainly by affecting transcription factors (TFs) binding in human cancers. This led to the urgent need for comprehensively and effectively collecting distinct cis-regulatory elements and TF-binding sites (TFBS) to annotate DNA methylation regulation. RESULTS: We developed a database (CanMethdb, http://meth.liclab.net/CanMethdb/) that focused on the upstream and downstream annotations for CpG-genes in cancers. This included upstream cis-regulatory elements, especially those involving distal regions to genes, and TFBS annotations for the CpGs and downstream functional annotations for the target genes, computed through integrating abundant DNA methylation and gene expression profiles in diverse cancers. Users could inquire CpG-target gene pairs for a cancer type through inputting a genomic region, a CpG, a gene name, or select hypo/hypermethylated CpG sets. The current version of CanMethdb documented a total of 38 986 060 CpG-target gene pairs (with 6 769 130 unique pairs), involving 385 217 CpGs and 18 044 target genes, abundant cis-regulatory elements and TFs for 33 TCGA cancer types. CanMethdb might help biologists perform in-depth studies of target gene regulations based on DNA methylations in cancer. AVAILABILITY AND IMPLEMENTATION: The main program is available at https://github.com/chunquanlipathway/CanMethdb. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Metilação de DNA , Neoplasias , Humanos , Fatores de Transcrição/metabolismo , Genoma , Sequências Reguladoras de Ácido Nucleico , Regiões Promotoras Genéticas , Neoplasias/genética , DNA/metabolismo , Ilhas de CpG
18.
Metab Eng ; 82: 250-261, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38428728

RESUMO

Gastrodin, a phenolic glycoside, is a prominent component of Gastrodia elata, which is renowned for its sedative, hypnotic, anticonvulsant, and neuroprotective activities. Engineering heterologous production of plant natural products in microbial host represents a safe, cost-effective, and scalable alternative to plant extraction. Here, we present the construction of an engineered Yarrowia lipolytica yeast that achieves a high-titer production of gastrodin. We systematically refactored the yeast genome by enhancing the flux of the shikimate pathway and optimizing the glucosyl transfer system. We introduced more than five dozen of genetic modifications onto the yeast genome, including enzyme screening, alleviation of rate-limiting steps, promoter selection, genomic integration site optimization, downregulation of competing pathways, and elimination of gastrodin degradation. Meanwhile, we developed a Copper-induced Antisense-Transcriptional Regulation (CATR) tool. The developed CATR toolkit achieved dynamic repression and activation of violacein synthesis through the addition of copper in Y. lipolytica. This strategy was further used to dynamically regulate the pyruvate kinase node to effectively redirect glycolytic flux towards the shikimate pathway while maintaining cell growth at proper rate. Taken together, these efforts resulted in 9477.1 mg/L of gastrodin in shaking flaks and 13.4 g/L of gastrodin with a yield of 0.149 g/g glucose in a 5-L bioreactor, highlighting the potential for large-scale and sustainable production of gastrodin from microbial fermentation.


Assuntos
Cobre , Yarrowia , Ácido Chiquímico , Glucosídeos , Álcoois Benzílicos , Yarrowia/genética
19.
Bioconjug Chem ; 35(5): 703-714, 2024 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-38708860

RESUMO

Manganese(II)-based contrast agents (MBCAs) are potential candidates for gadolinium-free enhanced magnetic resonance imaging (MRI). In this work, a rigid binuclear MBCA (Mn2-PhDTA2) with a zero-length linker was developed via facile synthetic routes, while the other dimer (Mn2-TPA-PhDTA2) with a longer rigid linker was also synthesized via more complex steps. Although the molecular weight of Mn2-PhDTA2 is lower than that of Mn2-TPA-PhDTA2, their T1 relaxivities are similar, being increased by over 71% compared to the mononuclear Mn-PhDTA. In the presence of serum albumin, the relaxivity of Mn2-PhDTA2 was slightly lower than that of Mn2-TPA-PhDTA2, possibly due to the lower affinity constant. The transmetalation reaction with copper(II) ions confirmed that Mn2-PhDTA2 has an ideal kinetic inertness with a dissociation half-life of approximately 10.4 h under physiological conditions. In the variable-temperature 17O NMR study, both Mn-PhDTA and Mn2-PhDTA2 demonstrated a similar estimated q close to 1, indicating the formation of monohydrated complexes with each manganese(II) ion. In addition, Mn2-PhDTA2 demonstrated a superior contrast enhancement to Mn-PhDTA in in vivo vascular and hepatic MRI and can be rapidly cleared through a dual hepatic and renal excretion pattern. The hepatic uptake mechanism of Mn2-PhDTA2 mediated by SLC39A14 was validated in cellular uptake studies.


Assuntos
Meios de Contraste , Fígado , Imageamento por Ressonância Magnética , Manganês , Manganês/química , Fígado/diagnóstico por imagem , Fígado/metabolismo , Imageamento por Ressonância Magnética/métodos , Animais , Meios de Contraste/química , Meios de Contraste/síntese química , Humanos , Proteínas de Transporte de Cátions/metabolismo , Proteínas de Transporte de Cátions/química , Camundongos , Complexos de Coordenação/química , Complexos de Coordenação/síntese química
20.
Blood ; 139(21): 3204-3221, 2022 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-35259210

RESUMO

Bone marrow-derived mesenchymal stem cells (BMSCs) support bone formation and constitute the stromal niche in regulating hematopoietic stem cells (HSCs). Stromal niche dysfunction affects HSC engraftment during transplantation; however, the underlying mechanisms remain elusive. In the present study, we found that all-trans retinoic acid (ATRA) and inflammation stress upregulated retinoic acid-inducible gene I (RIG-I) in BMSCs. Excess RIG-I expression damaged the clonogenicity, bone-forming ability of BMSCs and particularly their stromal niche function that supports HSC expansion in vitro and engraftment in vivo. Mechanistically, RIG-I elevation promoted the degradation of NRF2, a checkpoint for antioxidant cellular response, by altering the RIG-I-Trim25-Keap1-NRF2 complex, leading to reactive oxygen species (ROS) accumulation and BMSC damage. Genetic inhibition of RIG-I sustained NRF2 protein levels and reduced ROS levels in ATRA-treated BMSCs, thus preserving their clonogenicity, bone-forming ability, and stromal niche function in supporting HSC engraftment in mice. More importantly, RIG-I inhibition recovered the ATRA-treated stromal niche function to enhance HSC engraftment and emergency myelopoiesis for innate immunity against the bacterium Listeria monocytogenes during transplantation. Overall, we identified a noncanonical role of RIG-I in the regulation of the stromal niche for HSC transplantation.


Assuntos
Transplante de Medula Óssea , Proteína DEAD-box 58/metabolismo , Fator 2 Relacionado a NF-E2 , Animais , Células-Tronco Hematopoéticas/metabolismo , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Camundongos , Espécies Reativas de Oxigênio/metabolismo , Nicho de Células-Tronco/fisiologia
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