Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 620
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
Mol Cell ; 84(12): 2304-2319.e8, 2024 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-38838666

RESUMEN

Circular RNAs (circRNAs) are upregulated during neurogenesis. Where and how circRNAs are localized and what roles they play during this process have remained elusive. Comparing the nuclear and cytoplasmic circRNAs between H9 cells and H9-derived forebrain (FB) neurons, we identify that a subset of adenosine (A)-rich circRNAs are restricted in H9 nuclei but exported to cytosols upon differentiation. Such a subcellular relocation of circRNAs is modulated by the poly(A)-binding protein PABPC1. In the H9 nucleus, newly produced (A)-rich circRNAs are bound by PABPC1 and trapped by the nuclear basket protein TPR to prevent their export. Modulating (A)-rich motifs in circRNAs alters their subcellular localization, and introducing (A)-rich circRNAs in H9 cytosols results in mRNA translation suppression. Moreover, decreased nuclear PABPC1 upon neuronal differentiation enables the export of (A)-rich circRNAs, including circRTN4(2,3), which is required for neurite outgrowth. These findings uncover subcellular localization features of circRNAs, linking their processing and function during neurogenesis.


Asunto(s)
Transporte Activo de Núcleo Celular , Adenosina , Núcleo Celular , Neurogénesis , Neuronas , Proteína I de Unión a Poli(A) , ARN Circular , ARN , ARN Circular/metabolismo , ARN Circular/genética , Neuronas/metabolismo , Adenosina/metabolismo , Núcleo Celular/metabolismo , Humanos , Proteína I de Unión a Poli(A)/metabolismo , Proteína I de Unión a Poli(A)/genética , Animales , ARN/metabolismo , ARN/genética , Línea Celular , Diferenciación Celular , Citoplasma/metabolismo , Prosencéfalo/metabolismo
2.
Nature ; 632(8026): 762-767, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39169246

RESUMEN

The photoelectric effect is not truly instantaneous but exhibits attosecond delays that can reveal complex molecular dynamics1-7. Sub-femtosecond-duration light pulses provide the requisite tools to resolve the dynamics of photoionization8-12. Accordingly, the past decade has produced a large volume of work on photoionization delays following single-photon absorption of an extreme ultraviolet photon. However, the measurement of time-resolved core-level photoionization remained out of reach. The required X-ray photon energies needed for core-level photoionization were not available with attosecond tabletop sources. Here we report measurements of the X-ray photoemission delay of core-level electrons, with unexpectedly large delays, ranging up to 700 as in NO near the oxygen K-shell threshold. These measurements exploit attosecond soft X-ray pulses from a free-electron laser to scan across the entire region near the K-shell threshold. Furthermore, we find that the delay spectrum is richly modulated, suggesting several contributions, including transient trapping of the photoelectron owing to shape resonances, collisions with the Auger-Meitner electron that is emitted in the rapid non-radiative relaxation of the molecule and multi-electron scattering effects. The results demonstrate how X-ray attosecond experiments, supported by comprehensive theoretical modelling, can unravel the complex correlated dynamics of core-level photoionization.

3.
Nature ; 615(7952): 526-534, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36890225

RESUMEN

The nucleolus is the most prominent membraneless condensate in the nucleus. It comprises hundreds of proteins with distinct roles in the rapid transcription of ribosomal RNA (rRNA) and efficient processing within units comprising a fibrillar centre and a dense fibrillar component and ribosome assembly in a granular component1. The precise localization of most nucleolar proteins and whether their specific localization contributes to the radial flux of pre-rRNA processing have remained unknown owing to insufficient resolution in imaging studies2-5. Therefore, how these nucleolar proteins are functionally coordinated with stepwise pre-rRNA processing requires further investigation. Here we screened 200 candidate nucleolar proteins using high-resolution live-cell microscopy and identified 12 proteins that are enriched towards the periphery of the dense fibrillar component (PDFC). Among these proteins, unhealthy ribosome biogenesis 1 (URB1) is a static, nucleolar protein that ensures 3' end pre-rRNA anchoring and folding for U8 small nucleolar RNA recognition and the subsequent removal of the 3' external transcribed spacer (ETS) at the dense fibrillar component-PDFC boundary. URB1 depletion leads to a disrupted PDFC, uncontrolled pre-rRNA movement, altered pre-rRNA conformation and retention of the 3' ETS. These aberrant 3' ETS-attached pre-rRNA intermediates activate exosome-dependent nucleolar surveillance, resulting in decreased 28S rRNA production, head malformations in zebrafish and delayed embryonic development in mice. This study provides insight into functional sub-nucleolar organization and identifies a physiologically essential step in rRNA maturation that requires the static protein URB1 in the phase-separated nucleolus.


Asunto(s)
Nucléolo Celular , Exosomas , Precursores del ARN , Procesamiento Postranscripcional del ARN , ARN Ribosómico , Pez Cebra , Animales , Ratones , Nucléolo Celular/metabolismo , Desarrollo Embrionario , Exosomas/metabolismo , Cabeza/anomalías , Microscopía , Proteínas Nucleares/metabolismo , Precursores del ARN/metabolismo , ARN Ribosómico/genética , ARN Ribosómico/metabolismo , ARN Ribosómico 28S/metabolismo , Pez Cebra/genética , Pez Cebra/metabolismo
4.
Mol Cell ; 76(6): 981-997.e7, 2019 12 19.
Artículo en Inglés | MEDLINE | ID: mdl-31757757

RESUMEN

Visualizing the location and dynamics of RNAs in live cells is key to understanding their function. Here, we identify two endonuclease-deficient, single-component programmable RNA-guided and RNA-targeting Cas13 RNases (dCas13s) that allow robust real-time imaging and tracking of RNAs in live cells, even when using single 20- to 27-nt-long guide RNAs. Compared to the aptamer-based MS2-MCP strategy, an optimized dCas13 system is user friendly, does not require genetic manipulation, and achieves comparable RNA-labeling efficiency. We demonstrate that the dCas13 system is capable of labeling NEAT1, SatIII, MUC4, and GCN4 RNAs and allows the study of paraspeckle-associated NEAT1 dynamics. Applying orthogonal dCas13 proteins or combining dCas13 and MS2-MCP allows dual-color imaging of RNAs in single cells. Further combination of dCas13 and dCas9 systems allows simultaneous visualization of genomic DNA and RNA transcripts in living cells.


Asunto(s)
Imagen Molecular/métodos , ARN/fisiología , Imagen Individual de Molécula/métodos , Sistemas CRISPR-Cas/genética , Línea Celular Tumoral , Colorantes Fluorescentes/química , Humanos , Mucina 4 , Ingeniería de Proteínas/métodos , ARN Guía de Kinetoplastida/genética , ARN Largo no Codificante , Ribonucleasas/genética , Ribonucleasas/metabolismo , Coloración y Etiquetado/métodos
5.
J Biol Chem ; 300(8): 107592, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39032648

RESUMEN

MLH1 plays a critical role in DNA mismatch repair and genome maintenance. MLH1 deficiency promotes cancer development and progression, but the mechanism underlying MLH1 regulation remains enigmatic. In this study, we demonstrated that MLH1 protein is degraded by the ubiquitin-proteasome system and have identified vital cis-elements and trans-factors involved in MLH1 turnover. We found that the region encompassing the amino acids 516 to 650 is crucial for MLH1 degradation. The mismatch repair protein PMS2 may shield MLH1 from degradation as it binds to the MLH1 segment key to its turnover. Furthermore, we have identified the E3 ubiquitin ligase UBR4 and the deubiquitylase USP5, which oppositely modulate MLH1 stability. In consistence, UBR4 or USP5 deficiency affects the cellular response to nucleotide analog 6-TG, supporting their roles in regulating mismatch repair. Our study has revealed important insights into the regulatory mechanisms underlying MLH1 proteolysis, critical to DNA mismatch repair related diseases.


Asunto(s)
Reparación de la Incompatibilidad de ADN , Homólogo 1 de la Proteína MutL , Proteolisis , Ubiquitina-Proteína Ligasas , Homólogo 1 de la Proteína MutL/metabolismo , Homólogo 1 de la Proteína MutL/genética , Humanos , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitina-Proteína Ligasas/genética , Estabilidad Proteica , Endonucleasa PMS2 de Reparación del Emparejamiento Incorrecto/metabolismo , Endonucleasa PMS2 de Reparación del Emparejamiento Incorrecto/genética , Proteasas Ubiquitina-Específicas/metabolismo , Proteasas Ubiquitina-Específicas/genética , Células HEK293
6.
Plant J ; 119(5): 2484-2499, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39007841

RESUMEN

Pathogen infection induces massive reprogramming of host primary metabolism. Lipid and fatty acid (FA) metabolism is generally disrupted by pathogens and co-opted for their proliferation. Lipid droplets (LDs) that play important roles in regulating cellular lipid metabolism are utilized by a variety of pathogens in mammalian cells. However, the function of LDs during pathogenic infection in plants remains unknown. We show here that infection by rice black streaked dwarf virus (RBSDV) affects the lipid metabolism of maize, which causes elevated accumulation of C18 polyunsaturated fatty acids (PUFAs) leading to viral proliferation and symptom development. The overexpression of one of the two novel LD-associated proteins (LDAPs) of maize (ZmLDAP1 and ZmLDAP2) induces LD clustering. The core capsid protein P8 of RBSDV interacts with ZmLDAP2 and prevents its degradation through the ubiquitin-proteasome system mediated by a UBX domain-containing protein, PUX10. In addition, silencing of ZmLDAP2 downregulates the expression of FA desaturase genes in maize, leading to a decrease in C18 PUFAs levels and suppression of RBSDV accumulation. Our findings reveal that plant virus may recruit LDAP to regulate cellular FA metabolism to promote viral multiplication and infection. These results expand the knowledge of LD functions and viral infection mechanisms in plants.


Asunto(s)
Ácidos Grasos , Enfermedades de las Plantas , Proteínas de Plantas , Replicación Viral , Zea mays , Zea mays/virología , Zea mays/metabolismo , Zea mays/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Enfermedades de las Plantas/virología , Ácidos Grasos/metabolismo , Metabolismo de los Lípidos , Proteínas Asociadas a Gotas Lipídicas/metabolismo , Proteínas Asociadas a Gotas Lipídicas/genética , Gotas Lipídicas/metabolismo , Gotas Lipídicas/virología , Virus de Plantas/fisiología , Regulación de la Expresión Génica de las Plantas , Reoviridae/fisiología
7.
Proc Natl Acad Sci U S A ; 119(50): e2202938119, 2022 12 13.
Artículo en Inglés | MEDLINE | ID: mdl-36469767

RESUMEN

Using epitope- and structure-based multiepitope fusion antigen vaccinology platform, we constructed a polyvalent protein immunogen that presents antigenic domains (epitopes) of Vibrio cholerae toxin-coregulated pilus A, cholera toxin (CT), sialidase, hemolysin A, flagellins (B, C, and D), and peptides mimicking lipopolysaccharide O-antigen on a flagellin B backbone. Mice and rabbits immunized intramuscularly with this polyvalent protein immunogen developed antibodies to all of the virulence factors targeted by the immunogen except lipopolysaccharide. Mouse and rabbit antibodies exhibited functional activities against CT enterotoxicity, CT binding to GM1 ganglioside, bacterial motility, and in vitro adherence of V. cholerae O1, O139, and non-O1/non-O139 serogroup strains. When challenged orogastrically with V. cholerae O1 El Tor N16961 or a non-O1/non-O139 strain, rabbits IM immunized with the immunogen showed a 2-log (99%) reduction in V. cholerae colonization of small intestines. Moreover, infant rabbits born to the mother immunized with the protein immunogen acquired antibodies passively and were protected from bacterial intestinal colonization (>2-log reduction), severe diarrhea (100%), and mild diarrhea (88%) after infection with V. cholerae O1 El Tor (N16961), O1 classical (O395), O139 (Bengal), or a non-O1/non-O139 strain. This study demonstrated that this polyvalent cholera protein is broadly immunogenic and cross-protective, and an adult rabbit colonization model and an infant rabbit passive protection model fill a gap in preclinical efficacy assessment in cholera vaccine development.


Asunto(s)
Cólera , Vibrio cholerae , Conejos , Ratones , Animales , Cólera/prevención & control , Cólera/microbiología , Lipopolisacáridos , Vibrio cholerae/metabolismo , Toxina del Cólera , Diarrea/prevención & control
8.
Angiogenesis ; 27(3): 351-373, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38498232

RESUMEN

Age-related macular degeneration (AMD) is a common retinal neurodegenerative disease among the elderly. Neovascular AMD (nAMD), a leading cause of AMD-related blindness, involves choroidal neovascularization (CNV), which can be suppressed by anti-angiogenic treatments. However, current CNV treatments do not work in all nAMD patients. Here we investigate a novel target for AMD. Granzyme B (GzmB) is a serine protease that promotes aging, chronic inflammation and vascular permeability through the degradation of the extracellular matrix (ECM) and tight junctions. Extracellular GzmB is increased in retina pigment epithelium (RPE) and mast cells in the choroid of the healthy aging outer retina. It is further increased in donor eyes exhibiting features of nAMD and CNV. Here, we show in RPE-choroidal explant cultures that exogenous GzmB degrades the RPE-choroid ECM, promotes retinal/choroidal inflammation and angiogenesis while diminishing anti-angiogenic factor, thrombospondin-1 (TSP-1). The pharmacological inhibition of either GzmB or mast-cell degranulation significantly reduces choroidal angiogenesis. In line with our in vitro data, GzmB-deficiency reduces the extent of laser-induced CNV lesions and the age-related deterioration of electroretinogram (ERG) responses in mice. These findings suggest that targeting GzmB, a serine protease with no known endogenous inhibitors, may be a potential novel therapeutic approach to suppress CNV in nAMD.


Asunto(s)
Neovascularización Coroidal , Matriz Extracelular , Granzimas , Inflamación , Mastocitos , Epitelio Pigmentado de la Retina , Granzimas/metabolismo , Neovascularización Coroidal/metabolismo , Neovascularización Coroidal/patología , Animales , Matriz Extracelular/metabolismo , Matriz Extracelular/patología , Humanos , Epitelio Pigmentado de la Retina/metabolismo , Epitelio Pigmentado de la Retina/patología , Inflamación/patología , Inflamación/metabolismo , Ratones , Mastocitos/metabolismo , Mastocitos/patología , Mastocitos/enzimología , Trombospondina 1/metabolismo , Trombospondina 1/genética , Ratones Endogámicos C57BL , Coroides/patología , Coroides/metabolismo , Coroides/irrigación sanguínea , Degeneración Macular/patología , Degeneración Macular/metabolismo , Ratones Noqueados
9.
Apoptosis ; 29(5-6): 835-848, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38573492

RESUMEN

Oxaliplatin resistance poses a significant challenge in colorectal cancer (CRC) therapy, necessitating further investigation into the underlying molecular mechanisms. This study aimed to elucidate the regulatory role of SNHG4 in oxaliplatin resistance and ferroptosis in CRC. Our findings revealed that treatment with oxaliplatin led to downregulation of SNHG4 expression in CRC cells, while resistant CRC cells exhibited higher levels of SNHG4 compared to parental cells. Silencing SNHG4 attenuated oxaliplatin resistance and reduced the expression of resistance-related proteins MRD1 and MPR1. Furthermore, induction of ferroptosis effectively diminished oxaliplatin resistance in both parental and resistant CRC cells. Notably, ferroptosis induction resulted in decreased SNHG4 expression, whereas SNHG4 overexpression suppressed ferroptosis. Through FISH, RIP, and RNA pull-down assays, we identified the cytoplasmic localization of both SNHG4 and PTEN, establishing that SNHG4 directly targets PTEN, thereby reducing mRNA stability in CRC cells. Silencing PTEN abrogated the impact of SNHG4 on oxaliplatin resistance and ferroptosis in CRC cells. In vivo experiments further validated the influence of SNHG4 on oxaliplatin resistance and ferroptosis in CRC cells through PTEN regulation. In conclusion, SNHG4 promotes resistance to oxaliplatin in CRC cells by suppressing ferroptosis through instability of PTEN, thus serves as a target for patients with oxaliplatin-base chemoresistance.


Asunto(s)
Neoplasias Colorrectales , Resistencia a Antineoplásicos , Ferroptosis , Oxaliplatino , Fosfohidrolasa PTEN , Animales , Humanos , Ratones , Antineoplásicos/farmacología , Línea Celular Tumoral , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/patología , Neoplasias Colorrectales/metabolismo , Resistencia a Antineoplásicos/genética , Resistencia a Antineoplásicos/efectos de los fármacos , Ferroptosis/efectos de los fármacos , Ferroptosis/genética , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Ratones Desnudos , Oxaliplatino/farmacología , Fosfohidrolasa PTEN/metabolismo , Fosfohidrolasa PTEN/genética , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Ensayos Antitumor por Modelo de Xenoinjerto , Masculino
10.
Cancer Immunol Immunother ; 73(4): 71, 2024 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-38430394

RESUMEN

BACKGROUND: Due to individual differences in tumors and immune systems, the response rate to immunotherapy is low in lung adenocarcinoma (LUAD) patients. Combinations with other therapeutic strategies improve the efficacy of immunotherapy in LUAD patients. Although radioimmunotherapy has been demonstrated to effectively suppress tumors, the underlying mechanisms still need to be investigated. METHODS: Total RNA from LUAD cells was sequenced before and after radiotherapy to identify differentially expressed radiation-associated genes. The similarity network fusion (SNF) algorithm was applied for molecular classification based on radiation-related genes, immune-related genes, methylation data, and somatic mutation data. The changes in gene expression, prognosis, immune cell infiltration, radiosensitivity, chemosensitivity, and sensitivity to immunotherapy were assessed for each subtype. RESULTS: We used the SNF algorithm and multi-omics data to divide TCGA-LUAD patients into three subtypes. Patients with the CS3 subtype had the best prognosis, while those with the CS1 and CS2 subtypes had poorer prognoses. Among the strains tested, CS2 exhibited the most elevated immune cell infiltration and expression of immune checkpoint genes, while CS1 exhibited the least. Patients in the CS2 subgroup were more likely to respond to PD-1 immunotherapy. The CS2 patients were most sensitive to docetaxel and cisplatin, while the CS1 patients were most sensitive to paclitaxel. Experimental validation of signature genes in the CS2 subtype showed that inhibiting the expression of RHCG and TRPA1 could enhance the sensitivity of lung cancer cells to radiation. CONCLUSIONS: In summary, this study identified a risk classifier based on multi-omics data that can guide treatment selection for LUAD patients.


Asunto(s)
Adenocarcinoma del Pulmón , Neoplasias Pulmonares , Humanos , Multiómica , Adenocarcinoma del Pulmón/genética , Adenocarcinoma del Pulmón/terapia , Inmunoterapia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/terapia , Análisis por Conglomerados , Pronóstico
11.
Small ; 20(12): e2307500, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37940631

RESUMEN

The promising cyclometalated iridium (III) complexes have been proved to possess great potential in vacuum-deposited organic light-emitting diodes (OLEDs) applications for full-color displays and white solid-state lighting sources. Herein, based on the unique bidentate ligand of dibenzo[a,c]phenazine (dbpz) group with strong conjugated effect of aromatic rings for red emission, four novel [3+2+1] coordinated iridium (III) emissive materials have been rationally designed and synthesized. The monodentate ligands of -CN and -OCN have been effectively employed to tune the deep-red emission of 628-675 nm with high photoluminescence quantum yields up to 98%. Moreover, all devices displayed deep-red color coordinates ranging from (0.675, 0.325) to (0.716, 0.284), which is close to the standard-red color coordinates of (0.708, 0.292), as recommended by International Telecommunication Union Radiocommunication (ITU-R) BT.2020. The device based on nBuIr(dbpz)CN with an exciplex cohost has exhibited maximum external quantum efficiencies of 20.7% and good stability. With nBuIr(dbpz)CN as an effective sensitizer, the nBuIr(dbpz)OCN based phosphorescent OLED devices have successfully demonstrated cascading energy transfer processes, contributing to pure red emission with maximum luminance as high as 6471 cd m-2. Therefore, this work has been successfully demonstrated rational molecular design strategy of [3+2+1] iridium complexes to obtain highly efficient deep-red electrophosphorescent emission.

12.
Small ; 20(31): e2310767, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38456772

RESUMEN

Artificial optoelectronic synapses (OES) have attracted extensive attention in brain-inspired information processing and neuromorphic computing. However, OES at near-infrared wavelengths have rarely been reported, seriously limiting the application in modern optical communication. Herein, high-performance near-infrared OES devices based on VO2/MoO3 heterojunctions are presented. The textured MoO3 films are deposited on the sputtered VO2 film by using the glancing-angle deposition technique to form a heterojunction device. Through tuning the oxygen defects in the VO2 film, the fabricated VO2/MoO3 heterojunction exhibits versatile electrical synaptic functions. Benefiting from the highly efficient light harvesting and the unique interface effect, the photonic synaptic characteristics, mainly including the short/long-term plasticity and learning experience behavior are successfully realized at the O (1342 nm) and C (1550 nm) optical communication wavebands. Moreover, a single OES device can output messages accurately by converting light signals of the Morse code to distinct synaptic currents. More importantly, a 3 × 3 artificial OES array is constructed to demonstrate the impressive image perceiving and learning capabilities. This work not only indicates the feasibility of defect and interface engineering in modulating the synaptic plasticity of OES devices, but also provides effective strategies to develop advanced artificial neuromorphic visual systems for next-generation optical communication systems.

13.
Small ; 20(24): e2311114, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38157494

RESUMEN

Due to the relatively low photoluminescence quantum yield (PLQY) and horizontal dipole orientation of doped films, anthracene-based fluorescent organic light-emitting diodes (F-OLEDs) have faced a great challenge to achieve high external quantum efficiency (EQE). Herein, a novel approach is introduced by incorporating penta-helicene into anthracene, presented as linear-shaped 3-(4-(10-phenylanthracen-9-yl)phenyl)dibenzo[c,g]phenanthrene (BABH) and 3-(4-(10-(naphthalen-2-yl)anthracen-9-yl)phenyl)dibenzo[c,g]phenanthrene (NABH). These blue hosts exhibit minimal intermolecular overlap of π-π stacking, effectively suppressing excimer formation, which facilitates the effective transfer of singlet energy to the fluorescent dopant for PLQY as high as 90%. Additionally, the as-obtained two hosts of BABH and NABH have effectively demonstrated major horizontal components transition dipole moments (TDM) and high thermal stability with glass transitional temperature (Tg) surpassing 188 °C, enhancing the horizontal dipole orientation of their doped films to be 89% and 93%, respectively. The OLEDs based on BABH and NABH exhibit excellent EQE of 10.5% and 12.4% at 462 nm and device lifetime up to 90% of the initial luminance over 4500 h at 100 cd m-2, which has firmly established them as among the most efficient blue F-OLEDs based on anthracene to date to the best knowledge. This work provides an instructive strategy to design an effective host for highly efficient and stable F-OLEDs.

14.
Nat Methods ; 18(1): 51-59, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33288960

RESUMEN

Circular RNAs (circRNAs) produced from back-spliced exons are widely expressed, but individual circRNA functions remain poorly understood owing to the lack of adequate methods for distinguishing circRNAs from cognate messenger RNAs with overlapping exons. Here, we report that CRISPR-RfxCas13d can effectively discriminate circRNAs from mRNAs by using guide RNAs targeting sequences spanning back-splicing junction (BSJ) sites featured in RNA circles. Using a lentiviral library that targets sequences across BSJ sites of highly expressed human circRNAs, we show that a group of circRNAs are important for cell growth mostly in a cell-type-specific manner and that a common oncogenic circRNA, circFAM120A, promotes cell proliferation by preventing the mRNA for family with sequence similarity 120A (FAM120A) from binding the translation inhibitor IGF2BP2. Further application of RfxCas13d-BSJ-gRNA screening has uncovered circMan1a2, which has regulatory potential in mouse embryo preimplantation development. Together, these results establish CRISPR-RfxCas13d as a useful tool for the discovery and functional study of circRNAs at both individual and large-scale levels.


Asunto(s)
Sistemas CRISPR-Cas , Neoplasias del Colon/patología , Regulación Neoplásica de la Expresión Génica , ARN Circular/genética , ARN Mensajero/metabolismo , Proteínas de Unión al ARN/metabolismo , Empalme Alternativo , Animales , Apoptosis , Proliferación Celular , Neoplasias del Colon/genética , Neoplasias del Colon/metabolismo , Humanos , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , ARN Mensajero/genética , Proteínas de Unión al ARN/genética , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de Xenoinjerto
15.
Appl Environ Microbiol ; 90(8): e0098824, 2024 08 21.
Artículo en Inglés | MEDLINE | ID: mdl-39082807

RESUMEN

Shigella bacteria utilize the type III secretion system (T3SS) to invade host cells and establish local infection. Invasion plasmid antigen D (IpaD), a component of Shigella T3SS, has garnered extensive interest as a vaccine target, primarily due to its pivotal role in the Shigella invasion, immunogenic property, and a high degree of conservation across Shigella species and serotypes. Currently, we are developing an epitope- and structure-based multivalent vaccine against shigellosis and require functional epitope antigens of key Shigella virulence determinants including IpaD. However, individual IpaD B-cell epitopes, their contributions to the overall immunogenicity, and functional activities attributing to bacteria invasion have not been fully characterized. In this study, we predicted continuous B-cell epitopes in silico and fused each epitope to a carrier protein. Then, we immunized mice intramuscularly with each epitope fusion protein, examined the IpaD-specific antibody responses, and measured antibodies from each epitope fusion for the activity against Shigella invasion in vitro. Data showed that all epitope fusion proteins induced similar levels of anti-IpaD IgG antibodies in mice, and differences were noted for antibody inhibition activity against Shigella invasion. IpaD epitope 1 (SPGGNDGNSV), IpaD epitope 2 (LGGNGEVVLDNA), and IpaD epitope 5 (SPNNTNGSSTET) induced antibodies significantly better in inhibiting invasion from Shigella flexneri 2a, and epitopes 1 and 5 elicited antibodies more effectively at preventing invasion of Shigella sonnei. These results suggest that IpaD epitopes 1 and 5 can be the IpaD representative antigens for epitope-based polyvalent protein construction and protein-based cross-protective Shigella vaccine development.IMPORTANCEShigella is a leading cause of diarrhea in children younger than 5 years in developing countries (children's diarrhea) and continues to be a major threat to public health. No licensed vaccines are currently available against the heterogeneous Shigella species and serotype strains. Aiming to develop a cross-protective multivalent vaccine against shigellosis and dysentery, we applied novel multiepitope fusion antigen (MEFA) technology to construct a broadly immunogenic polyvalent protein antigen, by presenting functional epitopes of multiple Shigella virulence determinants on a backbone protein. The functional IpaD epitopes identified from this study will essentially allow us to construct an optimal polyvalent Shigella immunogen, leading to the development of a cross-protective vaccine against shigellosis (and dysentery) and the improvement of global health. In addition, identifying functional epitopes from heterogeneous virulence determinants and using them as antigenic representatives for the development of cross-protective multivalent vaccines can be applied generally in vaccine development.


Asunto(s)
Antígenos Bacterianos , Epítopos de Linfocito B , Shigella flexneri , Antígenos Bacterianos/inmunología , Antígenos Bacterianos/genética , Animales , Ratones , Shigella flexneri/inmunología , Shigella flexneri/genética , Epítopos de Linfocito B/inmunología , Vacunas contra la Shigella/inmunología , Vacunas contra la Shigella/administración & dosificación , Vacunas contra la Shigella/genética , Disentería Bacilar/prevención & control , Disentería Bacilar/inmunología , Disentería Bacilar/microbiología , Ratones Endogámicos BALB C , Mapeo Epitopo , Femenino , Shigella/inmunología , Shigella/genética , Proteínas Bacterianas/inmunología , Proteínas Bacterianas/genética , Anticuerpos Antibacterianos/inmunología , Anticuerpos Antibacterianos/sangre , Shigella sonnei/inmunología , Shigella sonnei/genética , Sistemas de Secreción Tipo III/inmunología , Sistemas de Secreción Tipo III/genética
16.
Microvasc Res ; 154: 104685, 2024 07.
Artículo en Inglés | MEDLINE | ID: mdl-38593952

RESUMEN

BACKGROUND: Coronary microvascular dysfunction (CMD) is frequently observed in atrial fibrillation (AF), the most commonly sustained arrhythmia. Nevertheless, an in-depth prognostic significance of CMD in AF is lacking. We aimed to provide insight into the predictive impact of CMD assessed by a novel non-invasive coronary angiography-derived index of microcirculatory resistance (caIMR) for major adverse events (MACE) in AF patients. METHOD: This study included patients with AF who underwent invasive coronary angiography due to suspected cardiac ischemia and did not exhibit obstructive epicardial coronary artery disease (≤50 % stenosis). The caIMR was prospectively evaluated, and the optimal cutoff value for predicting MACE was determined through ROC analysis. RESULT: A total of 463 patients with AF were enrolled. During a median of 33 months of follow-up, 111 (23.97 %) patients had MACE endpoints. The best caIMR cutoff value was 39.28. In patients with MACE, both the mean caIMR and the prevalence of elevated caIMR (caIMR>39.28) were significantly higher compared to those without MACE. An elevated caIMR was linked to a higher risk of MACE (log-rank P < 0.001) and emerged as an independent predictor of clinical outcomes (HR: 4.029; 95 % CI: 2.529-6.418; P < 0.001). In addition, the risk of MACE was higher in high caIMR patients with non-paroxysmal AF (log-rank P < 0.001) and no catheter ablation (log-rank P < 0.001). CONCLUSION: Elevated caIMR is common and showed a vital independent prognostic significance in AF patients. In addition to well-known risk factors, assessment of microvascular function can be a feasible approach for early prevention and a therapeutic target in AF patients.


Asunto(s)
Fibrilación Atrial , Angiografía Coronaria , Circulación Coronaria , Vasos Coronarios , Microcirculación , Valor Predictivo de las Pruebas , Humanos , Fibrilación Atrial/fisiopatología , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/mortalidad , Masculino , Femenino , Persona de Mediana Edad , Anciano , Factores de Riesgo , Vasos Coronarios/fisiopatología , Vasos Coronarios/diagnóstico por imagen , Pronóstico , Medición de Riesgo , Factores de Tiempo , Estudios Prospectivos , Resistencia Vascular , Enfermedad de la Arteria Coronaria/fisiopatología , Enfermedad de la Arteria Coronaria/mortalidad , Enfermedad de la Arteria Coronaria/diagnóstico , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/complicaciones
17.
Opt Lett ; 49(16): 4733-4736, 2024 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-39146147

RESUMEN

Random lasers (RLs), with their low spatial coherence, are ideal illumination sources for speckle-free imaging. However, it is still challenging for RLs to maintain low spatial coherence with the need for integration and directionality. Here, a disordered multimode random polymer fiber laser (RPFL) is proposed and implemented as a low-spatial-coherence light source. Compared to typical multimode optical fibers, the number of accommodated modes is increased by about 11×, the speckle contrast is reduced to 0.013, and the spatial coherence factor is reduced to 0.08. The low-spatial-coherence property enables RPFL to produce significantly superior imaging quality in both speckle-free imaging and non-invasive imaging through opacity. This study provides a strategy for an integrated speckle-free imaging system and paves the way for non-invasive imaging.

18.
Chemistry ; 30(37): e202401463, 2024 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-38699856

RESUMEN

Aqueous zinc-ion batteries are anticipated to be the next generation of important energy storage devices to replace lithium-ion batteries due to the ongoing use of lithium resources and the safety hazards associated with organic electrolytes in lithium-ion batteries. Manganese-based compounds, including MnOx materials, have prominent places among the many zinc-ion battery cathode materials. Additionally, Cu doping can cause the creation of an oxygen vacancy, which increases the material's internal electric field and enhances cycle stability. MnOx also has great cyclic stability and promotes ion transport. At a current density of 0.2 A g-1, the Cu/MnOx nanocomposite obtained a high specific capacitance of 304.4 mAh g-1. In addition, Cu/MnOx nanocomposites showed A high specific capacity of 198.9 mAh g-1 after 1000 cycles at a current density of 0.5 A g-1. Therefore, Cu/MnOx nanocomposites are expected to be a strong contender for the next generation of zinc-ion battery cathode materials in high energy density storage systems.

19.
BMC Cancer ; 24(1): 671, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38824581

RESUMEN

BACKGROUND: The role of novel circular RNAs (circRNAs) in colorectal cancer (CRC) remains to be determined. This study aimed to identify a novel circRNA involved in CRC pathogenesis, assess its diagnostic value, and construct a regulatory network. METHODS: Differential expression analysis was conducted using circRNA datasets to screen for differentially expressed circRNAs. The expression of selected circRNAs was validated in external datasets and clinical samples. Diagnostic value of plasma circRNA levels in CRC was assessed. A competing endogenous RNA (ceRNA) network was constructed for the circRNA using TCGA dataset. RESULTS: Analysis of datasets revealed that hsa_circ_101303 was significantly overexpressed in CRC tissues compared to normal tissues. The upregulation of hsa_circ_101303 in CRC tissues was further confirmed through the GSE138589 dataset and clinical samples. High expression of hsa_circ_101303 was associated with advanced N stage, M stage, and tumor stage in CRC. Plasma levels of hsa_circ_101303 were markedly elevated in CRC patients and exhibited moderate diagnostic ability for CRC (AUC = 0.738). The host gene of hsa_circ_101303 was also found to be related to the TNM stage of CRC. Nine miRNAs were identified as target miRNAs for hsa_circ_101303, and 27 genes were identified as targets of these miRNAs. Subsequently, a ceRNA network for hsa_circ_101303 was constructed to illustrate the interactions between the nine miRNAs and 27 genes. CONCLUSIONS: The study identifies hsa_circ_101303 as a highly expressed circRNA in CRC, which is associated with the progression of the disease. Plasma levels of hsa_circ_101303 show promising diagnostic potential for CRC. The ceRNA network for hsa_circ_101303 provides valuable insights into the regulatory mechanisms underlying CRC.


Asunto(s)
Biomarcadores de Tumor , Neoplasias Colorrectales , Regulación Neoplásica de la Expresión Génica , Redes Reguladoras de Genes , MicroARNs , ARN Circular , Humanos , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/diagnóstico , Neoplasias Colorrectales/sangre , Neoplasias Colorrectales/patología , ARN Circular/genética , ARN Circular/sangre , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/sangre , Masculino , Femenino , MicroARNs/genética , MicroARNs/sangre , Persona de Mediana Edad , Perfilación de la Expresión Génica , Estadificación de Neoplasias
20.
FASEB J ; 37(4): e22837, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36934389

RESUMEN

Breast cancer is the most frequently diagnosed malignancy and the leading cause of cancer-related deaths in women worldwide. Cancer-associated fibroblasts (CAFs) are one of the fundamental cellular components of the tumor microenvironment and play a critical role in the initiation, progression, and therapy resistance of breast cancer. However, the detailed molecular mechanisms of CAFs activation from normal fibroblasts (NFs) are still not well understood. In the present study, we reported that ZNF32 expression in breast cancer cells was negatively correlated with CAF-related markers (FSP1, α-SMA, and FAP) in stromal fibroblasts, and loss of ZNF32 promoted the activation of CAFs, as evidenced by the enhanced proliferation and contractility of CAFs. ZNF32 deficiency-mediated fibroblast activation promoted the growth and metastasis of breast cancer cells in vitro and in vivo. Mechanistically, we demonstrated that ZNF32 inhibited TGFB1 transcription by directly binding to the -1968/-1962 region of the TGFB1 promoter, leading to the prevention of fibroblast activation. Altogether, our findings reveal an important mechanism by which ZNF32 suppression increases the transcription of the TGFB1 gene in breast cancer cells, and subsequently, elevated levels of secretory TGF-ß stimulate NFs transformation into CAFs, which in turn facilitates the malignant progression of breast cancer. Our data implicated ZNF32 as a potential therapeutic strategy against breast cancer.


Asunto(s)
Neoplasias de la Mama , Fibroblastos Asociados al Cáncer , Humanos , Femenino , Fibroblastos Asociados al Cáncer/metabolismo , Neoplasias de la Mama/metabolismo , Fibroblastos/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Proliferación Celular , Microambiente Tumoral/genética , Factor de Crecimiento Transformador beta1/genética , Factor de Crecimiento Transformador beta1/metabolismo , Factores de Transcripción de Tipo Kruppel/metabolismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA