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1.
Cell ; 173(5): 1165-1178.e20, 2018 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-29706548

RESUMO

Cohesin extrusion is thought to play a central role in establishing the architecture of mammalian genomes. However, extrusion has not been visualized in vivo, and thus, its functional impact and energetics are unknown. Using ultra-deep Hi-C, we show that loop domains form by a process that requires cohesin ATPases. Once formed, however, loops and compartments are maintained for hours without energy input. Strikingly, without ATP, we observe the emergence of hundreds of CTCF-independent loops that link regulatory DNA. We also identify architectural "stripes," where a loop anchor interacts with entire domains at high frequency. Stripes often tether super-enhancers to cognate promoters, and in B cells, they facilitate Igh transcription and recombination. Stripe anchors represent major hotspots for topoisomerase-mediated lesions, which promote chromosomal translocations and cancer. In plasmacytomas, stripes can deregulate Igh-translocated oncogenes. We propose that higher organisms have coopted cohesin extrusion to enhance transcription and recombination, with implications for tumor development.


Assuntos
Trifosfato de Adenosina/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Genoma , Animais , Linfócitos B/citologia , Linfócitos B/metabolismo , Fator de Ligação a CCCTC/genética , Fator de Ligação a CCCTC/metabolismo , Proteínas de Ciclo Celular/química , Proteínas de Ciclo Celular/genética , Linhagem Celular , Proteoglicanas de Sulfatos de Condroitina/genética , Proteoglicanas de Sulfatos de Condroitina/metabolismo , Cromatina/metabolismo , Proteínas Cromossômicas não Histona/química , Proteínas Cromossômicas não Histona/genética , Cromossomos/metabolismo , Proteínas de Ligação a DNA , Humanos , Camundongos , Mutagênese , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transcrição Gênica , Coesinas
2.
Cell ; 163(7): 1611-27, 2015 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-26686651

RESUMO

Spatial genome organization and its effect on transcription remains a fundamental question. We applied an advanced chromatin interaction analysis by paired-end tag sequencing (ChIA-PET) strategy to comprehensively map higher-order chromosome folding and specific chromatin interactions mediated by CCCTC-binding factor (CTCF) and RNA polymerase II (RNAPII) with haplotype specificity and nucleotide resolution in different human cell lineages. We find that CTCF/cohesin-mediated interaction anchors serve as structural foci for spatial organization of constitutive genes concordant with CTCF-motif orientation, whereas RNAPII interacts within these structures by selectively drawing cell-type-specific genes toward CTCF foci for coordinated transcription. Furthermore, we show that haplotype variants and allelic interactions have differential effects on chromosome configuration, influencing gene expression, and may provide mechanistic insights into functions associated with disease susceptibility. 3D genome simulation suggests a model of chromatin folding around chromosomal axes, where CTCF is involved in defining the interface between condensed and open compartments for structural regulation. Our 3D genome strategy thus provides unique insights in the topological mechanism of human variations and diseases.


Assuntos
Cromatina/química , Genoma Humano , Proteínas Repressoras/metabolismo , Transcrição Gênica , Animais , Fator de Ligação a CCCTC , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular , Cromatina/genética , Cromatina/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Cromossomos/metabolismo , Empacotamento do DNA , Humanos , RNA Polimerase II/metabolismo , Salamandridae , Coesinas
4.
Nucleic Acids Res ; 52(17): 10220-10234, 2024 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-39149894

RESUMO

The 3D chromatin organization plays a major role in the control of gene expression. However, our comprehension of the governing principles behind nuclear organization remains incomplete. Particularly, the spatial segregation of loci with similar repressive transcriptional states in plants poses a significant yet poorly understood puzzle. In this study, employing a combination of genetics and advanced 3D genomics approaches, we demonstrated that a redistribution of facultative heterochromatin marks in regions usually occupied by constitutive heterochromatin marks disrupts the 3D genome compartmentalisation. This disturbance, in turn, triggers novel chromatin interactions between genic and transposable element (TE) regions. Interestingly, our results imply that epigenetic features, constrained by genetic factors, intricately mold the landscape of 3D genome organisation. This study sheds light on the profound genetic-epigenetic interplay that underlies the regulation of gene expression within the intricate framework of the 3D genome. Our findings highlight the complexity of the relationships between genetic determinants and epigenetic features in shaping the dynamic configuration of the 3D genome.


Assuntos
Arabidopsis , Elementos de DNA Transponíveis , Epigênese Genética , Genoma de Planta , Heterocromatina , Elementos de DNA Transponíveis/genética , Heterocromatina/metabolismo , Heterocromatina/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Cromatina/metabolismo , Cromatina/genética , Histonas/metabolismo , Histonas/genética , Genômica/métodos
5.
Nucleic Acids Res ; 51(17): 9001-9018, 2023 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-37572350

RESUMO

Photoperiods integrate with the circadian clock to coordinate gene expression rhythms and thus ensure plant fitness to the environment. Genome-wide characterization and comparison of rhythmic genes under different light conditions revealed delayed phase under constant darkness (DD) and reduced amplitude under constant light (LL) in rice. Interestingly, ChIP-seq and RNA-seq profiling of rhythmic genes exhibit synchronous circadian oscillation in H3K9ac modifications at their loci and long non-coding RNAs (lncRNAs) expression at proximal loci. To investigate how gene expression rhythm is regulated in rice, we profiled the open chromatin regions and transcription factor (TF) footprints by time-series ATAC-seq. Although open chromatin regions did not show circadian change, a significant number of TFs were identified to rhythmically associate with chromatin and drive gene expression in a time-dependent manner. Further transcriptional regulatory networks mapping uncovered significant correlation between core clock genes and transcription factors involved in light/temperature signaling. In situ Hi-C of ZT8-specific expressed genes displayed highly connected chromatin association at the same time, whereas this ZT8 chromatin connection network dissociates at ZT20, suggesting the circadian control of gene expression by dynamic spatial chromatin conformation. These findings together implicate the existence of a synchronization mechanism between circadian H3K9ac modifications, chromatin association of TF and gene expression, and provides insights into circadian dynamics of spatial chromatin conformation that associate with gene expression rhythms.


Assuntos
Ritmo Circadiano , Oryza , Cromatina/genética , Relógios Circadianos/genética , Ritmo Circadiano/genética , Epigenoma , Perfilação da Expressão Gênica , Oryza/genética , Oryza/fisiologia , Fatores de Transcrição/genética
6.
J Am Chem Soc ; 146(20): 14357-14367, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38726589

RESUMO

Introducing dynamic behavior into periodic frameworks has borne fruit in the form of flexible porous crystals. The detailed molecular design of frameworks in order to control their collective dynamics is of particular interest, for example, to achieve stimulus-induced behavior. Herein, by varying the degree of rigidity of ditopic pillar linkers, two isostructural flexible metal-organic frameworks (MOFs) with common rigid supermolecular building bilayers were constructed. The subtle substitution of single (in bibenzyl-4,4'-dicarboxylic acid; H2BBDC) with double (in 4,4'-stilbenedicarboxylic acid; H2SDC) C-C bonds in pillared linkers led to markedly different flexible behavior of these two MOFs. Upon the removal of guest molecules, both frameworks clearly show reversible single-crystal-to-single-crystal transformations involving the cis-trans conformation change and a resulting swing of the corresponding pillar linkers, which gives rise to Flex-Cd-MOF-1a and Flex-Cd-MOF-2a, respectively. Strikingly, a more favorable gas-induced dynamic behavior in Flex-Cd-MOF-2a was verified in detail by stepwise C3H6/C3H8 sorption isotherms and the corresponding in situ powder X-ray diffraction experiments. These insights are strongly supported by molecular modeling studies on the sorption mechanism that explores the sorption landscape. Furthermore, a consistency between the macroscopic elasticity and microscopic flexibility of Flex-Cd-MOF-2 was observed. This work fuels a growing interest in developing MOFs with desired chemomechanical functions and presents detailed insights into the origins of flexible MOFs.

7.
BMC Biol ; 21(1): 241, 2023 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-37907908

RESUMO

BACKGROUND: Epigenetic modifications that exhibit circadian oscillations also promote circadian oscillations of gene expression. Brassica napus is a heterozygous polyploid species that has undergone distant hybridization and genome doubling events and has a young and distinct species origin. Studies incorporating circadian rhythm analysis of epigenetic modifications can offer new insights into differences in diurnal oscillation behavior among subgenomes and the regulation of diverse expressions of homologous gene rhythms in biological clocks. RESULTS: In this study, we created a high-resolution and multioscillatory gene expression dataset, active histone modification (H3K4me3, H3K9ac), and RNAPII recruitment in Brassica napus. We also conducted the pioneering characterization of the diurnal rhythm of transcription and epigenetic modifications in an allopolyploid species. We compared the evolution of diurnal rhythms between subgenomes and observed that the Cn subgenome had higher diurnal oscillation activity in both transcription and active histone modifications than the An subgenome. Compared to the A subgenome in Brassica rapa, the An subgenome of Brassica napus displayed significant changes in diurnal oscillation characteristics of transcription. Homologous gene pairs exhibited a higher proportion of diurnal oscillation in transcription than subgenome-specific genes, attributed to higher chromatin accessibility and abundance of active epigenetic modification types. We found that the diurnal expression of homologous genes displayed diversity, and the redundancy of the circadian system resulted in extensive changes in the diurnal rhythm characteristics of clock genes after distant hybridization and genome duplication events. Epigenetic modifications influenced the differences in the diurnal rhythm of homologous gene expression, and the diurnal oscillation of homologous gene expression was affected by the combination of multiple histone modifications. CONCLUSIONS: Herein, we presented, for the first time, a characterization of the diurnal rhythm characteristics of gene expression and its epigenetic modifications in an allopolyploid species. Our discoveries shed light on the epigenetic factors responsible for the diurnal oscillation activity imbalance between subgenomes and homologous genes' rhythmic expression differences. The comprehensive time-series dataset we generated for gene expression and epigenetic modifications provides a valuable resource for future investigations into the regulatory mechanisms of protein-coding genes in Brassica napus.


Assuntos
Brassica napus , Brassica napus/genética , Poliploidia , Ritmo Circadiano/genética , Genoma de Planta
8.
N Engl J Med ; 382(8): 727-733, 2020 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-31978945

RESUMO

In December 2019, a cluster of patients with pneumonia of unknown cause was linked to a seafood wholesale market in Wuhan, China. A previously unknown betacoronavirus was discovered through the use of unbiased sequencing in samples from patients with pneumonia. Human airway epithelial cells were used to isolate a novel coronavirus, named 2019-nCoV, which formed a clade within the subgenus sarbecovirus, Orthocoronavirinae subfamily. Different from both MERS-CoV and SARS-CoV, 2019-nCoV is the seventh member of the family of coronaviruses that infect humans. Enhanced surveillance and further investigation are ongoing. (Funded by the National Key Research and Development Program of China and the National Major Project for Control and Prevention of Infectious Disease in China.).


Assuntos
Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/virologia , Pulmão/diagnóstico por imagem , Pneumonia Viral/virologia , Adulto , Betacoronavirus/genética , Betacoronavirus/ultraestrutura , Líquido da Lavagem Broncoalveolar/virologia , COVID-19 , Células Cultivadas , China , Infecções por Coronavirus/diagnóstico por imagem , Infecções por Coronavirus/patologia , Células Epiteliais/patologia , Células Epiteliais/virologia , Feminino , Genoma Viral , Humanos , Pulmão/patologia , Pulmão/virologia , Masculino , Microscopia Eletrônica de Transmissão , Pessoa de Meia-Idade , Filogenia , Pneumonia Viral/diagnóstico por imagem , Pneumonia Viral/patologia , Radiografia Torácica , Sistema Respiratório/patologia , Sistema Respiratório/virologia , SARS-CoV-2
9.
N Engl J Med ; 382(19): 1787-1799, 2020 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-32187464

RESUMO

BACKGROUND: No therapeutics have yet been proven effective for the treatment of severe illness caused by SARS-CoV-2. METHODS: We conducted a randomized, controlled, open-label trial involving hospitalized adult patients with confirmed SARS-CoV-2 infection, which causes the respiratory illness Covid-19, and an oxygen saturation (Sao2) of 94% or less while they were breathing ambient air or a ratio of the partial pressure of oxygen (Pao2) to the fraction of inspired oxygen (Fio2) of less than 300 mm Hg. Patients were randomly assigned in a 1:1 ratio to receive either lopinavir-ritonavir (400 mg and 100 mg, respectively) twice a day for 14 days, in addition to standard care, or standard care alone. The primary end point was the time to clinical improvement, defined as the time from randomization to either an improvement of two points on a seven-category ordinal scale or discharge from the hospital, whichever came first. RESULTS: A total of 199 patients with laboratory-confirmed SARS-CoV-2 infection underwent randomization; 99 were assigned to the lopinavir-ritonavir group, and 100 to the standard-care group. Treatment with lopinavir-ritonavir was not associated with a difference from standard care in the time to clinical improvement (hazard ratio for clinical improvement, 1.31; 95% confidence interval [CI], 0.95 to 1.80). Mortality at 28 days was similar in the lopinavir-ritonavir group and the standard-care group (19.2% vs. 25.0%; difference, -5.8 percentage points; 95% CI, -17.3 to 5.7). The percentages of patients with detectable viral RNA at various time points were similar. In a modified intention-to-treat analysis, lopinavir-ritonavir led to a median time to clinical improvement that was shorter by 1 day than that observed with standard care (hazard ratio, 1.39; 95% CI, 1.00 to 1.91). Gastrointestinal adverse events were more common in the lopinavir-ritonavir group, but serious adverse events were more common in the standard-care group. Lopinavir-ritonavir treatment was stopped early in 13 patients (13.8%) because of adverse events. CONCLUSIONS: In hospitalized adult patients with severe Covid-19, no benefit was observed with lopinavir-ritonavir treatment beyond standard care. Future trials in patients with severe illness may help to confirm or exclude the possibility of a treatment benefit. (Funded by Major Projects of National Science and Technology on New Drug Creation and Development and others; Chinese Clinical Trial Register number, ChiCTR2000029308.).


Assuntos
Antivirais/uso terapêutico , Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/tratamento farmacológico , Inibidores do Citocromo P-450 CYP3A/uso terapêutico , Lopinavir/uso terapêutico , Pneumonia Viral/tratamento farmacológico , Ritonavir/uso terapêutico , Adulto , Idoso , Antivirais/efeitos adversos , Betacoronavirus/genética , COVID-19 , Teste para COVID-19 , Técnicas de Laboratório Clínico , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/mortalidade , Infecções por Coronavirus/virologia , Inibidores do Citocromo P-450 CYP3A/efeitos adversos , Quimioterapia Combinada , Feminino , Mortalidade Hospitalar , Humanos , Análise de Intenção de Tratamento , Lopinavir/efeitos adversos , Masculino , Pessoa de Meia-Idade , Pandemias , Gravidade do Paciente , Pneumonia Viral/mortalidade , Pneumonia Viral/virologia , Modelos de Riscos Proporcionais , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Ritonavir/efeitos adversos , SARS-CoV-2 , Tempo para o Tratamento , Falha de Tratamento , Carga Viral
10.
Plant Biotechnol J ; 21(11): 2333-2347, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37539491

RESUMO

DNA methylation plays an important role in gene regulation and genomic stability. However, large DNA hypomethylated regions known as DNA methylation valleys (DMVs) or canyons have also been suggested to serve unique regulatory functions, largely unknown in rice (Oryza sativa). Here, we describe the DMVs in rice seedlings, which were highly enriched with developmental and transcription regulatory genes. Further detailed analysis indicated that grand DMVs (gDMVs) might be derived from nuclear integrants of organelle DNA (NORGs). Furthermore, Domains Rearranged Methylase 2 (OsDRM2) maintained DNA methylation at short DMV (sDMV) shores. Epigenetic maps indicated that sDMVs were marked with H3K4me3 and/or H3K27me3, although the loss of DNA methylation had a negligible effect on histone modification within these regions. In addition, we constructed H3K27me3-associated interaction maps for homozygous T-DNA insertion mutant of the gene (osdrm2) and wild type (WT). From a global perspective, most (90%) compartments were stable between osdrm2 and WT plants. At a high resolution, we observed a dramatic loss of long-range chromatin loops in osdrm2, which suffered an extensive loss of non-CG (CHG and CHH, H = A, T, or C) methylation. From another viewpoint, the loss of non-CG methylation at sDMV shores in osdrm2 could disrupt H3K27me3-mediated chromatin interaction networks. Overall, our results demonstrated that DMVs are a key genomic feature in rice and are precisely regulated by epigenetic modifications, including DNA methylation and histone modifications. OsDRM2 maintained DNA methylation at sDMV shores, while OsDRM2 deficiency strongly affected three-dimensional (3D) genome architectures.


Assuntos
Metilação de DNA , Oryza , Metilação de DNA/genética , Cromatina/genética , Histonas/genética , Histonas/metabolismo , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Metiltransferases/genética , DNA , Regulação da Expressão Gênica de Plantas/genética
11.
Mol Psychiatry ; 27(6): 2777-2786, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35365808

RESUMO

ARID4A plays an important role in regulating gene expression and cell proliferation. ARID4A belongs to the AT-rich interaction domain (ARID)-containing family, and a PWWP domain immediately precedes its ARID region. The molecular mechanism and structural basis of ARID4A are largely unknown. Whole-exome sequencing (WES) revealed that a novel heterozygous missense variant, ARID4A c.1231 C > G (p.His411Asp), was associated with schizophrenia (SCZ) in this study. We determined the crystal structure of the PWWP-ARID tandem at 2.05 Å, revealing an unexpected mode in which ARID4A assembles with its PWWP and ARID from a structural and functional supramodule. Our results further showed that compared with the wild type, the p.His411Asp ARID mutant protein adopts a less compact conformation and exhibits a weaker dsDNA-binding ability. The p.His411Asp mutation decreased the number of cells that were arrested in the G0-G1 phase and caused more cells to progress to the G2-M phase. In addition, the missense mutation promoted the proliferation of HEK293T cells. In conclusion, our data provide evidence that ARID4A p.His411Asp could cause a conformational change in the ARID4A ARID domain, influence the DNA binding function, and subsequently disturb the cell cycle arrest in the G1 phase. ARID4A is likely a susceptibility gene for SCZ; thus, these findings provide new insight into the role of ARID4A in psychiatric disorders.


Assuntos
Mutação de Sentido Incorreto , Proteína 1 de Ligação ao Retinoblastoma , Esquizofrenia , China , DNA , Células HEK293 , Humanos , Proteína 1 de Ligação ao Retinoblastoma/genética , Proteína 1 de Ligação ao Retinoblastoma/metabolismo , Esquizofrenia/genética , Esquizofrenia/metabolismo , Irmãos
12.
Inorg Chem ; 62(17): 6751-6758, 2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-37083265

RESUMO

Metal-organic frameworks (MOFs) have been recognized as a potential platform for the development of tunable luminophores owing to their highly modulable structures and components. Herein, two MOF luminophores based on Cd(II) ions, 1,3,5-tri(4-pyridinyl)benzene (TPB), and 1,4-dicarboxybenzene (H2BDC) were constructed. The directed assembly of the metal ions and organic linkers results in [Cd2(BDC)2(TPB)(H2O)]·x(solvent) (MOF-1) featuring TPB-based blue fluorescence centered at 425 nm. By introducing anthracene as the structure directing agent (SDA) for assembly regulation, [Cd2(BDC)(TPB)2(NO3)2]·x(solvent) (MOF-2) was obtained, which reveals anthracene feeding-dependent high tunable emission in the 517-650 nm range. Detailed components, photophysical properties, and structural characteristics investigations of MOF-2 indicate the TPB and NO3- interactions as the origin of its redshifted emission compared with that of MOF-1. Furthermore, the fluorescence of MOF-2 was found to be regulatable by the anthracene feeding based on the SDA-determined crystallinity of the crystalline sample. All these results provided a unique example of the structural and fluorescence regulation of MOF luminophores.

13.
J Biomed Inform ; 139: 104301, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36746345

RESUMO

Medicine recommendation aims to provide a combination of medicine based on the patient's electronic health record (EHR), which is an essential task in healthcare. Existing methods either base recommendations on EHRs or provide models with knowledge of drug-drug interactions (DDIs) to achieve DDI reduction. However, the former models the patient's health history but ignores undesirable DDIs, while the latter lacks mining of patient health records and gets low recommendation accuracy. Therefore, this study contributes to research on personalized medication recommendations that consider drug interaction effects and models the patient's past medical history. In this paper, the Distance-wise and Graph Contrastive Learning (DGCL) framework is proposed. Specifically, we develop a two-stage neural network module for clinical record learning. We propose the distance detection loss to model the difference between the output distribution of current cases and historical records. In the DDI recognition and control task, DGCL proposes a graph contrastive learning method to jointly train the DDI knowledge graph and the electronic record graph, thereby effectively controlling the level of DDI for recommended medications. By comparing the performance on the MIMIC-III dataset with several baselines, DGCL outperforms other models in terms of efficacy and safety.


Assuntos
Registros Eletrônicos de Saúde , Registros de Saúde Pessoal , Humanos , Interações Medicamentosas , Redes Neurais de Computação , Conhecimento
14.
J Biomed Inform ; 146: 104496, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37704104

RESUMO

Automatic radiology report generation has the potential to alert inexperienced radiologists to misdiagnoses or missed diagnoses and improve healthcare delivery efficiency by reducing the documentation workload of radiologists. Motivated by the continuous development of automatic image captioning, more and more deep learning methods have been proposed for automatic radiology report generation. However, the visual and textual data bias problem still face many challenges in the medical domain. Additionally, do not integrate medical knowledge, ignoring the mutual influences between medical findings, and abundant unlabeled medical images influence the accuracy of generating report. In this paper, we propose a Medical Knowledge with Contrastive Learning model (MKCL) to enhance radiology report generation. The proposed model MKCL uses IU Medical Knowledge Graph (IU-MKG) to mine the relationship among medical findings and improve the accuracy of identifying positive diseases findings from radiologic medical images. In particular, we design Knowledge Enhanced Attention (KEA), which integrates the IU-MKG and the extracted chest radiological visual features to alleviate textual data bias. Meanwhile, this paper leverages supervised contrastive learning to relieve radiographic medical images which have not been labeled, and identify abnormalities from images. Experimental results on the public dataset IU X-ray show that our proposed model MKCL outperforms other state-of-the-art report generation methods. Ablation studies also demonstrate that IU medical knowledge graph module and supervised contrastive learning module enhance the ability of the model to detect the abnormal parts and accurately describe the abnormal findings. The source code is available at: https://github.com/Eleanorhxd/MKCL.


Assuntos
Radiologia , Humanos , Documentação , Conhecimento , Radiografia , Radiologistas , Aprendizagem
15.
PLoS Genet ; 16(4): e1008764, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32330129

RESUMO

Enhancers are cis-acting DNA segments with the ability to increase target gene expression. They show high sensitivity to DNase and contain specific DNA elements in an open chromatin state that allows the binding of transcription factors (TFs). While numerous enhancers are annotated in the maize genome, few have been characterized genetically. KERNEL ROW NUMBER4 (KRN4), an intergenic quantitative trait locus for kernel row number, is assumed to be a cis-regulatory element of UNBRANCHED3 (UB3), a key inflorescence gene. However, the mechanism by which KRN4 controls UB3 expression remains unclear. Here, we found that KRN4 exhibits an open chromatin state, harboring sequences that showed high enhancer activity toward the 35S and UB3 promoters. KRN4 is bound by UB2-centered transcription complexes and interacts with the UB3 promoter by three duplex interactions to affect UB3 expression. Sequence variation at KRN4 enhances ub2 and ub3 mutant ear fasciation. Therefore, we suggest that KRN4 functions as a distal enhancer of the UB3 promoter via chromatin interactions and recruitment of UB2-centered transcription complexes for the fine-tuning of UB3 expression in meristems of ear inflorescences. These results provide evidence that an intergenic region helps to finely tune gene expression, providing a new perspective on the genetic control of quantitative traits.


Assuntos
Elementos Facilitadores Genéticos , Regulação da Expressão Gênica de Plantas , Zea mays/genética , Montagem e Desmontagem da Cromatina , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Regiões Promotoras Genéticas , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Ativação Transcricional , Zea mays/crescimento & desenvolvimento
16.
BMC Bioinformatics ; 22(1): 590, 2021 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-34903164

RESUMO

BACKGROUND: Clinical notes are documents that contain detailed information about the health status of patients. Medical codes generally accompany them. However, the manual diagnosis is costly and error-prone. Moreover, large datasets in clinical diagnosis are susceptible to noise labels because of erroneous manual annotation. Therefore, machine learning has been utilized to perform automatic diagnoses. Previous state-of-the-art (SOTA) models used convolutional neural networks to build document representations for predicting medical codes. However, the clinical notes are usually long-tailed. Moreover, most models fail to deal with the noise during code allocation. Therefore, denoising mechanism and long-tailed classification are the keys to automated coding at scale. RESULTS: In this paper, a new joint learning model is proposed to extend our attention model for predicting medical codes from clinical notes. On the MIMIC-III-50 dataset, our model outperforms all the baselines and SOTA models in all quantitative metrics. On the MIMIC-III-full dataset, our model outperforms in the macro-F1, micro-F1, macro-AUC, and precision at eight compared to the most advanced models. In addition, after introducing the denoising mechanism, the convergence speed of the model becomes faster, and the loss of the model is reduced overall. CONCLUSIONS: The innovations of our model are threefold: firstly, the code-specific representation can be identified by adopted the self-attention mechanism and the label attention mechanism. Secondly, the performance of the long-tailed distributions can be boosted by introducing the joint learning mechanism. Thirdly, the denoising mechanism is suitable for reducing the noise effects in medical code prediction. Finally, we evaluate the effectiveness of our model on the widely-used MIMIC-III datasets and achieve new SOTA results.


Assuntos
Registros Eletrônicos de Saúde , Classificação Internacional de Doenças , Humanos , Aprendizado de Máquina , Redes Neurais de Computação
17.
Lancet ; 395(10223): 497-506, 2020 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-31986264

RESUMO

BACKGROUND: A recent cluster of pneumonia cases in Wuhan, China, was caused by a novel betacoronavirus, the 2019 novel coronavirus (2019-nCoV). We report the epidemiological, clinical, laboratory, and radiological characteristics and treatment and clinical outcomes of these patients. METHODS: All patients with suspected 2019-nCoV were admitted to a designated hospital in Wuhan. We prospectively collected and analysed data on patients with laboratory-confirmed 2019-nCoV infection by real-time RT-PCR and next-generation sequencing. Data were obtained with standardised data collection forms shared by WHO and the International Severe Acute Respiratory and Emerging Infection Consortium from electronic medical records. Researchers also directly communicated with patients or their families to ascertain epidemiological and symptom data. Outcomes were also compared between patients who had been admitted to the intensive care unit (ICU) and those who had not. FINDINGS: By Jan 2, 2020, 41 admitted hospital patients had been identified as having laboratory-confirmed 2019-nCoV infection. Most of the infected patients were men (30 [73%] of 41); less than half had underlying diseases (13 [32%]), including diabetes (eight [20%]), hypertension (six [15%]), and cardiovascular disease (six [15%]). Median age was 49·0 years (IQR 41·0-58·0). 27 (66%) of 41 patients had been exposed to Huanan seafood market. One family cluster was found. Common symptoms at onset of illness were fever (40 [98%] of 41 patients), cough (31 [76%]), and myalgia or fatigue (18 [44%]); less common symptoms were sputum production (11 [28%] of 39), headache (three [8%] of 38), haemoptysis (two [5%] of 39), and diarrhoea (one [3%] of 38). Dyspnoea developed in 22 (55%) of 40 patients (median time from illness onset to dyspnoea 8·0 days [IQR 5·0-13·0]). 26 (63%) of 41 patients had lymphopenia. All 41 patients had pneumonia with abnormal findings on chest CT. Complications included acute respiratory distress syndrome (12 [29%]), RNAaemia (six [15%]), acute cardiac injury (five [12%]) and secondary infection (four [10%]). 13 (32%) patients were admitted to an ICU and six (15%) died. Compared with non-ICU patients, ICU patients had higher plasma levels of IL2, IL7, IL10, GSCF, IP10, MCP1, MIP1A, and TNFα. INTERPRETATION: The 2019-nCoV infection caused clusters of severe respiratory illness similar to severe acute respiratory syndrome coronavirus and was associated with ICU admission and high mortality. Major gaps in our knowledge of the origin, epidemiology, duration of human transmission, and clinical spectrum of disease need fulfilment by future studies. FUNDING: Ministry of Science and Technology, Chinese Academy of Medical Sciences, National Natural Science Foundation of China, and Beijing Municipal Science and Technology Commission.


Assuntos
Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/epidemiologia , Pneumonia Viral/diagnóstico , Pneumonia Viral/epidemiologia , Adulto , Distribuição por Idade , Idoso , COVID-19 , China/epidemiologia , Comorbidade , Infecções por Coronavirus/complicações , Infecções por Coronavirus/transmissão , Tosse/epidemiologia , Tosse/virologia , Feminino , Febre/epidemiologia , Febre/virologia , Hospitalização/estatística & dados numéricos , Humanos , Unidades de Terapia Intensiva/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Mialgia/epidemiologia , Mialgia/virologia , Pneumonia Viral/complicações , Pneumonia Viral/transmissão , Prognóstico , Radiografia Torácica , Síndrome do Desconforto Respiratório/epidemiologia , Síndrome do Desconforto Respiratório/virologia , Fatores de Tempo , Tomografia Computadorizada por Raios X , Adulto Jovem
18.
J Autoimmun ; 116: 102562, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33168359

RESUMO

Adult-onset Still's disease (AOSD) is a rare autoinflammatory disease with systemic involvement, and its pathophysiology remains unclear. Genome-wide association studies (GWAS) in the Chinese population have revealed an association between AOSD and the major histocompatibility complex (MHC) locus; however, causal variants in the MHC remain undetermined. In the present study, we identified independent amino-acid polymorphisms in human leukocyte antigen (HLA) molecules that are associated with Han Chinese patients with AOSD by fine-mapping the MHC locus. Through conditional analyses, we identified position 34 in HLA-DQα1 (p = 1.44 × 10-14) and Asn in HLA-DRß1 position 37 (p = 5.12 × 10-11) as the major determinants for AOSD. Moreover, we identified the associations for three main HLA class II alleles: HLA-DQB1*06:02 (OR = 2.70, p = 3.02 × 10-14), HLA-DRB1*15:01 (OR = 2.44, p = 3.66 × 10-13), and HLA-DQA1*01:02 (OR = 1.97, p = 1.09 × 10-9). This study reveals the relationship between functional variations in the class II HLA region and AOSD, implicating the MHC locus in the pathogenesis of AOSD.


Assuntos
Aminoácidos/genética , Predisposição Genética para Doença/genética , Cadeias alfa de HLA-DQ/genética , Cadeias HLA-DRB1/genética , Polimorfismo de Nucleotídeo Único , Doença de Still de Início Tardio/genética , Adulto , Alelos , Povo Asiático/genética , China , Frequência do Gene , Predisposição Genética para Doença/etnologia , Estudo de Associação Genômica Ampla/métodos , Genótipo , Cadeias alfa de HLA-DQ/química , Cadeias HLA-DRB1/química , Haplótipos , Humanos , Desequilíbrio de Ligação , Modelos Moleculares , Conformação Proteica , Doença de Still de Início Tardio/etnologia
19.
BMC Infect Dis ; 21(1): 1025, 2021 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-34592958

RESUMO

BACKGROUND: The immunoregulatory functions of regulatory T cells (Tregs) in the development and progression of some chronic infectious diseases are mediated by immune checkpoint molecules and immunosuppressive cytokines. However, little is known about the immunosuppressive functions of Tregs in human brucellosis, which is a major burden in low-income countries. In this study, expressions of immune checkpoint molecules and Treg-related cytokines in patients with acute and chronic Brucella infection were evaluated to explore their impact at different stages of infection. METHODS: Forty patients with acute brucellosis and 19 patients with chronic brucellosis admitted to the Third People's Hospital of Linfen in Shanxi Province between August 2016 and November 2017 were enrolled. Serum and peripheral blood mononuclear cells were isolated from patients before antibiotic treatment and from 30 healthy subjects. The frequency of Tregs (CD4+ CD25+ FoxP3+ T cells) and expression of CTLA-4, GITR, and PD-1 on Treg cells were detected by flow cytometry. Levels of Treg-related cytokines, including IL-35, TGF-ß1, and IL-10, were measured by customised multiplex cytokine assays using the Luminex platform. RESULTS: The frequency of Tregs was higher in chronic patients than in healthy controls (P = 0.026) and acute patients (P = 0.042); The frequency of CTLA-4+ Tregs in chronic patients was significantly higher than that in healthy controls (P = 0.011). The frequencies of GITR+ and PD-1+ Tregs were significantly higher in acute and chronic patients than in healthy controls (P < 0.05), with no significant difference between the acute and chronic groups (all P > 0.05). Serum TGF-ß1 levels were higher in chronic patients (P = 0.029) and serum IL-10 levels were higher in acute patients (P = 0.033) than in healthy controls. We detected weak correlations between serum TGF-ß1 levels and the frequencies of Tregs (R = 0.309, P = 0.031) and CTLA-4+ Tregs (R = 0.302, P = 0.035). CONCLUSIONS: Treg cell immunity is involved in the chronicity of Brucella infection and indicates the implication of Tregs in the prognosis of brucellosis. CTLA-4 and TGF-ß1 may contribute to Tregs-mediated immunosuppression in the chronic infection stage of a Brucella infection.


Assuntos
Brucelose , Linfócitos T Reguladores , Citocinas , Fatores de Transcrição Forkhead , Humanos , Proteínas de Checkpoint Imunológico , Leucócitos Mononucleares
20.
Appl Opt ; 60(14): 4245-4250, 2021 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-33983181

RESUMO

It is common for researchers to learn about the physical process of discharge by studying the intensity of specific spectral lines in the emission spectrum. By using this method, every microscopic process involving light radiation can be quantitatively analyzed, but there is a problem of how to select appropriate spectral lines for the comprehensive judgment of changes in the discharge process. Here, we present a comprehensive method for converting the visible spectrum of discharge into chromaticity coordinates. In this way, a large number of spectral data are transformed into a single chromaticity coordinate to diagnose the gas discharge directly and quickly, and the comprehensive evaluation of the discharge status is implemented.

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