Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 666
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Nature ; 629(8011): 467-473, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38471529

RESUMO

Prokaryotes have evolved intricate innate immune systems against phage infection1-7. Gabija is a highly widespread prokaryotic defence system that consists of two components, GajA and GajB8. GajA functions as a DNA endonuclease that is inactive in the presence of ATP9. Here, to explore how the Gabija system is activated for anti-phage defence, we report its cryo-electron microscopy structures in five states, including apo GajA, GajA in complex with DNA, GajA bound by ATP, apo GajA-GajB, and GajA-GajB in complex with ATP and Mg2+. GajA is a rhombus-shaped tetramer with its ATPase domain clustered at the centre and the topoisomerase-primase (Toprim) domain located peripherally. ATP binding at the ATPase domain stabilizes the insertion region within the ATPase domain, keeping the Toprim domain in a closed state. Upon ATP depletion by phages, the Toprim domain opens to bind and cleave the DNA substrate. GajB, which docks on GajA, is activated by the cleaved DNA, ultimately leading to prokaryotic cell death. Our study presents a mechanistic landscape of Gabija activation.


Assuntos
Bacillus cereus , Proteínas de Bactérias , Bacteriófagos , Microscopia Crioeletrônica , Imunidade Inata , Adenosina Trifosfatases/metabolismo , Adenosina Trifosfatases/química , Adenosina Trifosfatases/ultraestrutura , Trifosfato de Adenosina/química , Trifosfato de Adenosina/metabolismo , Apoproteínas/química , Apoproteínas/imunologia , Apoproteínas/metabolismo , Apoproteínas/ultraestrutura , Proteínas de Bactérias/química , Proteínas de Bactérias/imunologia , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/ultraestrutura , Bacteriófagos/imunologia , DNA/metabolismo , DNA/química , Clivagem do DNA , Magnésio/química , Magnésio/metabolismo , Modelos Moleculares , Ligação Proteica , Domínios Proteicos , Viabilidade Microbiana , Bacillus cereus/química , Bacillus cereus/imunologia , Bacillus cereus/metabolismo , Bacillus cereus/ultraestrutura , Estrutura Quaternária de Proteína , DNA Primase/química , DNA Primase/metabolismo , DNA Primase/ultraestrutura , DNA Topoisomerases/química , DNA Topoisomerases/metabolismo , DNA Topoisomerases/ultraestrutura
2.
Proc Natl Acad Sci U S A ; 120(13): e2217576120, 2023 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-36943878

RESUMO

Diabetes can result in impaired corneal wound healing. Mitochondrial dysfunction plays an important role in diabetic complications. However, the regulation of mitochondria function in the diabetic cornea and its impacts on wound healing remain elusive. The present study aimed to explore the molecular basis for the disturbed mitochondrial metabolism and subsequent wound healing impairment in the diabetic cornea. Seahorse analysis showed that mitochondrial oxidative phosphorylation is a major source of ATP production in human corneal epithelial cells. Live corneal biopsy punches from type 1 and type 2 diabetic mouse models showed impaired mitochondrial functions, correlating with impaired corneal wound healing, compared to nondiabetic controls. To approach the molecular basis for the impaired mitochondrial function, we found that Peroxisome Proliferator-Activated Receptor-α (PPARα) expression was downregulated in diabetic human corneas. Even without diabetes, global PPARα knockout mice and corneal epithelium-specific PPARα conditional knockout mice showed disturbed mitochondrial function and delayed wound healing in the cornea, similar to that in diabetic corneas. In contrast, fenofibrate, a PPARα agonist, ameliorated mitochondrial dysfunction and enhanced wound healing in the corneas of diabetic mice. Similarly, corneal epithelium-specific PPARα transgenic overexpression improved mitochondrial function and enhanced wound healing in the cornea. Furthermore, PPARα agonist ameliorated the mitochondrial dysfunction in primary human corneal epithelial cells exposed to diabetic stressors, which was impeded by siRNA knockdown of PPARα, suggesting a PPARα-dependent mechanism. These findings suggest that downregulation of PPARα plays an important role in the impaired mitochondrial function in the corneal epithelium and delayed corneal wound healing in diabetes.


Assuntos
Diabetes Mellitus Experimental , PPAR alfa , Camundongos , Humanos , Animais , PPAR alfa/genética , PPAR alfa/metabolismo , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/metabolismo , Córnea/metabolismo , Cicatrização/fisiologia , Camundongos Knockout , Mitocôndrias/metabolismo
3.
Proc Natl Acad Sci U S A ; 120(39): e2307722120, 2023 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-37725654

RESUMO

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


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , RNA Mitocondrial , Análise da Expressão Gênica de Célula Única , Mitocôndrias/genética
4.
Proc Natl Acad Sci U S A ; 119(33): e2207489119, 2022 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-35939707

RESUMO

The mechanistic target of rapamycin (mTOR) is assembled into signaling complexes of mTORC1 or mTORC2, and plays key roles in cell metabolism, stress response, and nutrient and growth factor sensing. Accumulating evidence from human and animal model studies has demonstrated a pathogenic role of hyperactive mTORC1 in age-related macular degeneration (AMD). The retinal pigment epithelium (RPE) is a primary injury site in AMD. In mouse models of RPE-specific deletion of Tuberous sclerosis 1 (Tsc1), which encodes an upstream suppressor of mTORC1, the hyperactivated mTORC1 metabolically reprogrammed the RPE and led to the degeneration of the outer retina and choroid (CH). In the current study, we use single-cell RNA sequencing (scRNA-seq) to identify an RPE mTORC1 downstream protein, dopamine- and cyclic AMP-regulated phosphoprotein of molecular weight 32,000 (DARPP-32). DARPP-32 was not found in healthy RPE but localized to drusen and basal linear deposits in human AMD eyes. In animal models, overexpressing DARPP-32 by adeno-associated virus (AAV) led to abnormal RPE structure and function. The data indicate that DARPP-32 is a previously unidentified signaling protein subjected to mTORC1 regulation and may contribute to RPE degeneration in AMD.


Assuntos
Fosfoproteína 32 Regulada por cAMP e Dopamina , Degeneração Macular , Alvo Mecanístico do Complexo 1 de Rapamicina , Epitélio Pigmentado da Retina , Animais , Modelos Animais de Doenças , Fosfoproteína 32 Regulada por cAMP e Dopamina/metabolismo , Ativação Enzimática , Humanos , Degeneração Macular/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Camundongos , Retina/metabolismo , Epitélio Pigmentado da Retina/metabolismo , Transdução de Sinais
5.
BMC Genomics ; 25(1): 434, 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38693497

RESUMO

BACKGROUND: WOX genes are a class of plant-specific transcription factors. The WUSCHEL-related homeobox (WOX) family is a member of the homeobox transcription factor superfamily. Previous studies have shown that WOX members play important roles in plant growth and development. However, studies of the WOX gene family in blueberry plants have not been reported. RESULTS: In order to understand the biological function of the WOX gene family in blueberries, bioinformatics were used methods to identify WOX gene family members in the blueberry genome, and analyzed the basic physical and chemical properties, gene structure, gene motifs, promoter cis-acting elements, chromosome location, evolutionary relationships, expression pattern of these family members and predicted their functions. Finally, 12 genes containing the WOX domain were identified and found to be distributed on eight chromosomes. Phylogenetic tree analysis showed that the blueberry WOX gene family had three major branches: ancient branch, middle branch, and WUS branch. Blueberry WOX gene family protein sequences differ in amino acid number, molecular weight, isoelectric point and hydrophobicity. Predictive analysis of promoter cis-acting elements showed that the promoters of the VdWOX genes contained abundant light response, hormone, and stress response elements. The VdWOX genes were induced to express in both stems and leaves in response to salt and drought stress. CONCLUSIONS: Our results provided comprehensive characteristics of the WOX gene family and important clues for further exploration of its role in the growth, development and resistance to various stress in blueberry plants.


Assuntos
Mirtilos Azuis (Planta) , Filogenia , Regiões Promotoras Genéticas , Mirtilos Azuis (Planta)/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas , Genoma de Planta , Família Multigênica , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Estresse Fisiológico/genética , Cromossomos de Plantas/genética , Evolução Molecular , Biologia Computacional/métodos
6.
Brief Bioinform ; 23(2)2022 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-35279714

RESUMO

Messenger RNA (mRNA) vaccines have shown great potential for anti-tumor therapy due to the advantages in safety, efficacy and industrial production. However, it remains a challenge to identify suitable cancer neoantigens that can be targeted for mRNA vaccines. Abnormal alternative splicing occurs in a variety of tumors, which may result in the translation of abnormal transcripts into tumor-specific proteins. High-throughput technologies make it possible for systematic characterization of alternative splicing as a source of suitable target neoantigens for mRNA vaccine development. Here, we summarized difficulties and challenges for identifying alternative splicing-derived cancer neoantigens from RNA-seq data and proposed a conceptual framework for designing personalized mRNA vaccines based on alternative splicing-derived cancer neoantigens. In addition, several points were presented to spark further discussion toward improving the identification of alternative splicing-derived cancer neoantigens.


Assuntos
Processamento Alternativo , Neoplasias , Antígenos de Neoplasias/genética , Humanos , Imunoterapia , Neoplasias/genética , Neoplasias/terapia , RNA Mensageiro/genética , Vacinas Sintéticas , Vacinas de mRNA
7.
Bioinformatics ; 39(10)2023 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-37740953

RESUMO

MOTIVATION: Cell-cell interactions (CCIs) play critical roles in many biological processes such as cellular differentiation, tissue homeostasis, and immune response. With the rapid development of high throughput single-cell RNA sequencing (scRNA-seq) technologies, it is of high importance to identify CCIs from the ever-increasing scRNA-seq data. However, limited by the algorithmic constraints, current computational methods based on statistical strategies ignore some key latent information contained in scRNA-seq data with high sparsity and heterogeneity. RESULTS: Here, we developed a deep learning framework named DeepCCI to identify meaningful CCIs from scRNA-seq data. Applications of DeepCCI to a wide range of publicly available datasets from diverse technologies and platforms demonstrate its ability to predict significant CCIs accurately and effectively. Powered by the flexible and easy-to-use software, DeepCCI can provide the one-stop solution to discover meaningful intercellular interactions and build CCI networks from scRNA-seq data. AVAILABILITY AND IMPLEMENTATION: The source code of DeepCCI is available online at https://github.com/JiangBioLab/DeepCCI.


Assuntos
Aprendizado Profundo , Perfilação da Expressão Gênica , Análise de Sequência de RNA , Análise de Célula Única , Software , Análise por Conglomerados
8.
Opt Lett ; 49(7): 1774-1777, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38560860

RESUMO

An ultra-broadband TM-pass polarizer is designed, fabricated, and experimentally demonstrated based on subwavelength grating (SWG) metamaterials in a lithium niobate on an insulator (LNOI) platform. According to our simulation, the designed device is predicted to work at a 220 nm wavelength range from 1460 to 1680 nm, covering the S-, C-, L-, U-bands of optical fiber communication. By depositing and subsequently etching a silicon nitride thin film atop the LNOI chip, the SWG structures are formed successfully by using complementary metal-oxide semiconductor (CMOS)-compatible fabrication processes. The measured results show a high polarization extinction ratio larger than 20 dB and a relatively low insertion loss below 2.5 dB over a 130 nm wavelength range from 1500 to 1630 nm, mainly limited by the operation bandwidth of our laser source.

9.
Oncology ; 102(2): 168-182, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37699361

RESUMO

INTRODUCTION: SMG5 is involved in tumor cell development and viewed as a potential target for immunotherapy. The purpose of this study was to systematically analyze the expression level, function, and prognostic value of SMG5 in pan-cancers. METHODS: Differential expression of SMG5 in normal and tumor tissues was analyzed using The Cancer Genome Atlas (TCGA) and the Genotype-Tissue Expression Database (GTEx) data. Survival analysis was performed by Kaplan-Meier method and Cox risk regression. The relationship between SMG5 expression and lymphocyte abundance, tumor cell immune infiltration level, molecular and immune subtypes as well as immune checkpoints was analyzed by tumor-immune system interactions database (TISIDB), Tumor Immune Estimation Resource (TIMER), and Sangerbox databases. The correlation between SMG5 and immune scores was studied using the Estimation of Stromal and Immune Cells in Malignant Tumours using Expression (ESTIMATE) data algorithm. Further, drug sensitivity analysis of SMG5 with low-grade glioma (LGG) was conducted using the CellMiner database. RESULTS: SMG5 was highly expressed in 23 tumors and only had a significant impact on the prognosis of patients with LGG only. In addition, in tumor microenvironment and tumor immune analysis, we found that the level of immune infiltration, tumor mutational load, microsatellite instability, and immune checkpoints of LGG were significantly correlated with SMG5 expression. Furthermore, SMG5 was significantly associated with immune scores, stromal scores, and sensitivity of some drugs in LGG. CONCLUSION: SMG5 is differentially expressed in several cancers and is significantly associated with prognosis, immune microenvironment, and immune checkpoints in LGG patients. Therefore, SMG5 could be a potential pan-cancer biomarker and an immunotherapeutic target for LGG.


Assuntos
Glioma , Humanos , Prognóstico , Biomarcadores Tumorais/genética , Algoritmos , Diferenciação Celular , Microambiente Tumoral , Proteínas de Transporte
10.
Arch Biochem Biophys ; 754: 109962, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38499055

RESUMO

Acetohydroxyacid synthase (AHAS) is one of the key enzymes of the biosynthesis of branched-chain amino acids, it is also an effective target for the screening of herbicides and antibiotics. In this study we present a method for preparing Escherichia coli AHAS I holoenzyme (EcAHAS I) with exceptional stability, which provides a solid ground for us to re-investigate the in vitro catalytic properties of the protein. The results show EcAHAS I synthesized in this way exhibits similar function to Bacillus subtilis acetolactate synthase in its catalysis with pyruvate and 2-ketobutyrate (2-KB) as dual-substrate, producing four 2-hydroxy-3-ketoacids including (S)-2-acetolactate, (S)-2-aceto-2-hydroxybutyrate, (S)-2-propionyllactate, and (S)-2-propionyl-2-hydroxybutyrate. Quantification of the reaction indicates that the two substrates almost totally consume, and compound (S)-2-aceto-2- hydroxybutyrate forms in the highest yield among the four major products. Moreover, the protein also condenses two molecules of 2-KB to furnish (S)-2-propionyl-2-hydroxybutyrate. Further exploration manifests that EcAHAS I ligates pyruvate/2-KB and nitrosobenzene to generate two arylhydroxamic acids N-hydroxy-N-phenylacetamide and N-hydroxy-N-phenyl- propionamide. These findings enhance our comprehension of the catalytic characteristics of EcAHAS I. Furthermore, the application of this enzyme as a catalyst in construction of C-N bonds displays promising potential.


Assuntos
Acetolactato Sintase , Escherichia coli , Acetolactato Sintase/química , Glicogênio Sintase , Hidroxibutiratos , Piruvatos , Holoenzimas
11.
Fish Shellfish Immunol ; 148: 109466, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38432538

RESUMO

To evade host antiviral response, viruses have evolved to take advantage of their noncoding RNAs (ncRNAs). Snakehead vesiculovirus (SHVV), a newly isolated fish rhabdovirus from diseased hybrid snakehead, has caused high mortality to the cultured snakehead fish during the past years in China. However, little is known about the mechanisms of its pathogenicity. Our study revealed that overexpression of the 30-nt leader RNA promoted SHVV replication. RNA-protein binding investigation revealed that SHVV leader RNA could interact with host 40S ribosomal protein S8 (RPS8) and 60S ribosomal protein L13a (L13a). Furthermore, we found that SHVV infection upregulated RPS8 and L13a, and in turn, overexpression of RPS8 or L13a inhibited, while knockdown of RPS8 or L13a promoted, SHVV replication, suggesting that RPS8 and L13a acted as host antiviral factors in response to SHVV infection. In addition, our study revealed that RPS8- or L13a-mediated inhibition of SHVV replication could be restored by co-transfection with leader RNA, suggesting that the interaction between leader RNA and RPS8 or L13a might affect the anti-SHVV effects of RPS8 and L13a. Taken together, these results suggest that SHVV leader RNA can interact with the host antiviral factors RPS8 and L13a, and promote SHVV replication. This study provides a better understanding of the molecular mechanism of the pathogenesis of SHVV and a potential antiviral strategy against SHVV infection.


Assuntos
Perciformes , Animais , Perciformes/fisiologia , Vesiculovirus/genética , RNA Viral/genética , Replicação Viral , Antivirais/farmacologia
12.
BMC Neurol ; 24(1): 45, 2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38273251

RESUMO

PURPOSE: To explore the predictive value of radiomics in predicting stroke-associated pneumonia (SAP) in acute ischemic stroke (AIS) patients and construct a prediction model based on clinical features and DWI-MRI radiomics features. METHODS: Univariate and multivariate logistic regression analyses were used to identify the independent clinical predictors for SAP. Pearson correlation analysis and the least absolute shrinkage and selection operator with ten-fold cross-validation were used to calculate the radiomics score for each feature and identify the predictive radiomics features for SAP. Multivariate logistic regression was used to combine the predictive radiomics features with the independent clinical predictors. The prediction performance of the SAP models was evaluated using receiver operating characteristics (ROC), calibration curves, decision curve analysis, and subgroup analyses. RESULTS: Triglycerides, the neutrophil-to-lymphocyte ratio, dysphagia, the National Institutes of Health Stroke Scale (NIHSS) score, and internal carotid artery stenosis were identified as clinically independent risk factors for SAP. The radiomics scores in patients with SAP were generally higher than in patients without SAP (P < 0. 05). There was a linear positive correlation between radiomics scores and NIHSS scores, as well as between radiomics scores and infarct volume. Infarct volume showed moderate performance in predicting the occurrence of SAP, with an AUC of 0.635. When compared with the other models, the combined prediction model achieved the best area under the ROC (AUC) in both training (AUC = 0.859, 95% CI 0.759-0.936) and validation (AUC = 0.830, 95% CI 0.758-0.896) cohorts (P < 0.05). The calibration curves and decision curve analysis further confirmed the clinical value of the nomogram. Subgroup analysis showed that this nomogram had potential generalization ability. CONCLUSION: The addition of the radiomics features to the clinical model improved the prediction of SAP in AIS patients, which verified its feasibility.


Assuntos
AVC Isquêmico , Pneumonia , Acidente Vascular Cerebral , Estados Unidos , Humanos , Estudos de Viabilidade , Radiômica , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/epidemiologia , Infarto
13.
Nanotechnology ; 35(20)2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38316042

RESUMO

A novel defect control approach based on laminated HfO2/ZrO2with multifunctional TiN/Mo/TiOxNyelectrode is proposed to significantly improve the endurance and data retention in HZO-based ferroelectric capacitor. The O-rich interface reduces leakage current and prolong the endurance up to 1011cycles while retaining a 2Pr value of 34 (µC cm-2) at 3.4 MV cm-1. Using first-principles calculations and experiments, we demonstrate that the enhancement of endurance is ascribed to the higher migration barrier of oxygen vacancies within the laminated HZO film and higher work function of MoOx/TiOxNybetween top electrode and the insulating oxide. This 2.5 nm thick TiOxNybarrier further increase the grain size of HZO, lowering the activation field and thus improving polarization reversal speed. This interfacial layer further decreases the overall capacitance, increases the depolarization field, thereby enhancing the data retention. By fitting the data using the Arrhenius equation, we demonstrate a 10 years data retention is achieved at 109.6 °C, surpassing traditional SS-HZO of 78.2 °C with a 450 °C rapid thermal annealing (required by backend-of-the-line). This work elucidates that interfacial engineering serves as a crucial technology capable of resolving the endurance, storage capability, and high-temperature data retention issues for ferroelectric memory.

14.
J Biochem Mol Toxicol ; 38(6): e23746, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38769694

RESUMO

To identify the role of enterotoxin-related genes in colorectal cancer (CRC) development and progression. Upregulated differentially expressed genes shared by three out of five Gene Expression Omnibus (GEO) data sets were included to screen the key enterotoxin-induced oncogenes (EIOGs) according to criteria oncogene definition, enrichment, and protein-protein interaction (PPI) network analysis, followed by prognosis survival, immune infiltration, and protential drugs analyses was performed via integration of RNA-sequencing data and The Cancer Genome Atlas-derived clinical profiles. We screened nine common key EIOGs from at least three GEO data sets. A Cox proportional hazards regression models verified that more alive cases, decreased overall survival, and highest 4-year survival prediction in CRC patients with high-risk score. Protein tyrosine phosphatase receptor type F polypeptide-interacting protein alpha-4 (PPFIA4), STY11, SCN3B, and SPTBN5 were shared in the same PPI network. Immune infiltration results showed that SCN3B and synaptotagmin 11 expression were obviously associated with B cell, macrophage, myeloid dendritic cell, neutrophils, and T cell CD4+ and CD8+ in both colon adenocarcinoma and rectal adenocarcinoma. CHIR-99021, MLN4924, and YK4-279 were identified as the potential drugs for treatment. Finally, upregulated EIOGs genes PPFIA4 and SCN3B were found in colon adenocarcinoma and PPFIA4 and SCN3B were proved to promote cell proliferation and migration in vitro. We demonstrated here that EIOGs promoting a malignancy phenotype was related with poor survival and prognosis in CRC, which might be served as novel therapeutic targets in CRC management.


Assuntos
Neoplasias Colorretais , Enterotoxinas , Humanos , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Progressão da Doença , Regulação Neoplásica da Expressão Gênica , Mapas de Interação de Proteínas
15.
Nature ; 555(7695): 231-236, 2018 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-29517002

RESUMO

Artificial superlattices, based on van der Waals heterostructures of two-dimensional atomic crystals such as graphene or molybdenum disulfide, offer technological opportunities beyond the reach of existing materials. Typical strategies for creating such artificial superlattices rely on arduous layer-by-layer exfoliation and restacking, with limited yield and reproducibility. The bottom-up approach of using chemical-vapour deposition produces high-quality heterostructures but becomes increasingly difficult for high-order superlattices. The intercalation of selected two-dimensional atomic crystals with alkali metal ions offers an alternative way to superlattice structures, but these usually have poor stability and seriously altered electronic properties. Here we report an electrochemical molecular intercalation approach to a new class of stable superlattices in which monolayer atomic crystals alternate with molecular layers. Using black phosphorus as a model system, we show that intercalation with cetyl-trimethylammonium bromide produces monolayer phosphorene molecular superlattices in which the interlayer distance is more than double that in black phosphorus, effectively isolating the phosphorene monolayers. Electrical transport studies of transistors fabricated from the monolayer phosphorene molecular superlattice show an on/off current ratio exceeding 107, along with excellent mobility and superior stability. We further show that several different two-dimensional atomic crystals, such as molybdenum disulfide and tungsten diselenide, can be intercalated with quaternary ammonium molecules of varying sizes and symmetries to produce a broad class of superlattices with tailored molecular structures, interlayer distances, phase compositions, electronic and optical properties. These studies define a versatile material platform for fundamental studies and potential technological applications.

16.
J Nanobiotechnology ; 22(1): 320, 2024 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-38849820

RESUMO

Simultaneously modulating the inflammatory microenvironment and promoting local bone regeneration is one of the main challenges in treating bone defects. In recent years, osteoimmunology has revealed that the immune system plays an essential regulatory role in bone regeneration and that macrophages are critical components. In this work, a mussel-inspired immunomodulatory and osteoinductive dual-functional hydroxyapatite nano platform (Gold/hydroxyapatite nanocomposites functionalized with polydopamine - PDA@Au-HA) is developed to accelerate bone tissues regeneration by regulating the immune microenvironment. PDA coating endows nanomaterials with the ability to scavenge reactive oxygen species (ROS) and anti-inflammatory properties, and it also exhibits an immunomodulatory ability to inhibit M1 macrophage polarization and activate M2 macrophage secretion of osteogenesis-related cytokines. Most importantly, this nano platform promotes the polarization of M2 macrophages and regulates the crosstalk between macrophages and pre-osteoblast cells to achieve bone regeneration. Au-HA can synergistically promote vascularized bone regeneration through sustained release of Ca and P particles and gold nanoparticles (NPs). This nano platform has a synergistic effect of good compatibility, scavenging of ROS, and anti-inflammatory and immunomodulatory capability to accelerate the bone repair process. Thus, our research offers a possible therapeutic approach by exploring PDA@Au-HA nanocomposites as a bifunctional platform for tissue regeneration.


Assuntos
Bivalves , Regeneração Óssea , Durapatita , Ouro , Indóis , Macrófagos , Osteogênese , Regeneração Óssea/efeitos dos fármacos , Durapatita/química , Durapatita/farmacologia , Animais , Camundongos , Ouro/química , Ouro/farmacologia , Bivalves/química , Células RAW 264.7 , Macrófagos/efeitos dos fármacos , Indóis/química , Indóis/farmacologia , Osteogênese/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Polímeros/química , Polímeros/farmacologia , Nanocompostos/química , Nanopartículas Metálicas/química , Osteoblastos/efeitos dos fármacos , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Fatores Imunológicos/farmacologia , Fatores Imunológicos/química , Citocinas/metabolismo
17.
Cell Mol Life Sci ; 80(10): 307, 2023 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-37768430

RESUMO

N-acetyltransferase 10 (NAT10)-mediated N4-acetylcytidine (ac4C) modification is crucial for mRNA stability and translation efficiency, yet the underlying function in mammalian preimplantation embryos remains unclear. Here, we characterized the ac4C modification landscape in mouse early embryos and found that the majority of embryos deficient in ac4C writer-NAT10 failed to develop into normal blastocysts. Through single-cell sequencing, RNA-seq, acetylated RNA immunoprecipitation combined with PCR (acRIP-PCR), and embryonic phenotype monitoring, Nop2 was screened as a target gene of Nat10. Mechanistically, Nat10 knockdown decreases the ac4C modification on Nop2 mRNA and reduces RNA and protein abundance by affecting the mRNA stability of Nop2. Then, depletion of NOP2 may inhibit the translation of transcription factor TEAD4, resulting in defective expression of the downstream lineage-specific gene Cdx2, and ultimately preventing blastomeres from undergoing the trophectoderm (TE) fate. However, exogenous Nop2 mRNA partially reverses this abnormal development. In conclusion, our findings demonstrate that defective ac4C modification of Nop2 mRNA hinders the morula-to-blastocyst transition by influencing the first cell fate decision in mice.

18.
Lung ; 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38958717

RESUMO

OBJECTIVES: This study was performed to construct and validate a risk prediction model for non-invasive ventilation (NIV) failure after birth in premature infants with gestational age < 32 weeks. METHODS: The data were derived from the multicenter retrospective study program - Jiangsu Provincial Neonatal Respiratory Failure Collaboration Network from Jan 2019 to Dec 2021. The subjects finally included were preterm infants using NIV after birth with gestational age less than 32 weeks and admission age within 72 h. After screening by inclusion and exclusion criteria, 1436 babies were subsequently recruited in the study, including 1235 infants in the successful NIV group and 201 infants in the failed NIV group. RESULTS: (1) Gestational age, 5 min Apgar, Max FiO2 during NIV, and FiO2 fluctuation value during NIV were selected by univariate and multivariate analysis. (2) The area under the curve of the prediction model was 0.807 (95% CI: 0.767-0.847) in the training set and 0.825 (95% CI: 0.766-0.883) in the test set. The calibration curve showed good agreement between the predicted probability and the actual observed probability (Mean absolute error = 0.008 for the training set; Mean absolute error = 0.012 for the test set). Decision curve analysis showed good clinical validity of the risk model in the training and test cohorts. CONCLUSION: This model performed well on dimensions of discrimination, calibration, and clinical validity. This model can serve as a useful tool for neonatologists to predict whether premature infants will experience NIV failure after birth.

19.
Nucleic Acids Res ; 50(22): e131, 2022 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-36250636

RESUMO

Recent advances in spatial transcriptomics (ST) have brought unprecedented opportunities to understand tissue organization and function in spatial context. However, it is still challenging to precisely dissect spatial domains with similar gene expression and histology in situ. Here, we present DeepST, an accurate and universal deep learning framework to identify spatial domains, which performs better than the existing state-of-the-art methods on benchmarking datasets of the human dorsolateral prefrontal cortex. Further testing on a breast cancer ST dataset, we showed that DeepST can dissect spatial domains in cancer tissue at a finer scale. Moreover, DeepST can achieve not only effective batch integration of ST data generated from multiple batches or different technologies, but also expandable capabilities for processing other spatial omics data. Together, our results demonstrate that DeepST has the exceptional capacity for identifying spatial domains, making it a desirable tool to gain novel insights from ST studies.


Assuntos
Aprendizado Profundo , Perfilação da Expressão Gênica , Humanos , Benchmarking , Perfilação da Expressão Gênica/métodos , Transcriptoma
20.
BMC Pediatr ; 24(1): 272, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38664650

RESUMO

INTRODUCTION: Neonatal respiratory failure (NRF) is a serious condition that often has high mortality and morbidity, effective interventions can be delivered in the future by identifying the risk factors associated with morbidity and mortality. However, recent advances in respiratory support have improved neonatal intensive care units (NICUs) care in China. We aimed to provide an updated review of the clinical profile and outcomes of NRF in the Jiangsu province. METHODS: Infants treated for NRF in the NICUs of 28 hospitals between March 2019 and March 2022 were retrospectively reviewed. Data collected included baseline perinatal and neonatal parameters, NICU admission- and treatment-related data, and patient outcomes in terms of mortality, major morbidity, and survival without major morbidities. RESULTS: A total of 5548 infants with NRF were included in the study. The most common primary respiratory disorder was respiratory distress syndrome (78.5%). NRF was managed with non-invasive and invasive respiratory support in 59.8% and 14.5% of patients, respectively. The application rate of surfactant therapy was 38.5%, while that of neonatal extracorporeal membrane oxygenation therapy was 0.2%. Mortality and major morbidity rates of 8.5% and 23.2% were observed, respectively. Congenital anomalies, hypoxic-ischemic encephalopathy, invasive respiratory support only and inhaled nitric oxide therapy were found to be significantly associated with the risk of death. Among surviving infants born at < 32 weeks of gestation or with a birth weight < 1500 g, caffeine therapy and repeat mechanical ventilation were demonstrated to significantly associate with increased major morbidity risk. CONCLUSION: Our study demonstrates the current clinical landscape of infants with NRF treated in the NICU, and, by proxy, highlights the ongoing advancements in the field of perinatal and neonatal intensive care in China.


Assuntos
Unidades de Terapia Intensiva Neonatal , Síndrome do Desconforto Respiratório do Recém-Nascido , Humanos , Recém-Nascido , China/epidemiologia , Estudos Retrospectivos , Feminino , Masculino , Síndrome do Desconforto Respiratório do Recém-Nascido/terapia , Insuficiência Respiratória/terapia , Surfactantes Pulmonares/uso terapêutico , Surfactantes Pulmonares/administração & dosagem , Oxigenação por Membrana Extracorpórea , Respiração Artificial/estatística & dados numéricos , Resultado do Tratamento
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa