Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 627
Filtrar
1.
Mol Cell ; 82(6): 1156-1168.e7, 2022 03 17.
Artículo en Inglés | MEDLINE | ID: mdl-35219383

RESUMEN

N6-methyladenosine (m6A) methylation is co-transcriptionally deposited on mRNA, but a possible role of m6A on transcription remains poorly understood. Here, we demonstrate that the METTL3/METTL14/WTAP m6A methyltransferase complex (MTC) is localized to many promoters and enhancers and deposits the m6A modification on nascent transcripts, including pre-mRNAs, promoter upstream transcripts (PROMPTs), and enhancer RNAs. PRO-seq analyses demonstrate that nascent RNAs originating from both promoters and enhancers are significantly decreased in the METTL3-depleted cells. Furthermore, genes targeted by the Integrator complex for premature termination are depleted of METTL3, suggesting a potential antagonistic relationship between METTL3 and Integrator. Consistently, we found the Integrator complex component INTS11 elevated at promoters and enhancers upon loss of MTC or nuclear m6A binders. Taken together, our findings suggest that MTC-mediated m6A modification protects nascent RNAs from Integrator-mediated termination and promotes productive transcription, thus unraveling an unexpected layer of gene regulation imposed by RNA m6A modification.


Asunto(s)
Cromatina , Metiltransferasas , Cromatina/genética , Metilación , Metiltransferasas/genética , Metiltransferasas/metabolismo , ARN/genética , ARN/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo
2.
Nature ; 612(7939): 259-265, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36443603

RESUMEN

The unique topology and physics of chiral superlattices make their self-assembly from nanoparticles highly sought after yet challenging in regard to (meta)materials1-3. Here we show that tetrahedral gold nanoparticles can transform from a perovskite-like, low-density phase with corner-to-corner connections into pinwheel assemblies with corner-to-edge connections and denser packing. Whereas corner-sharing assemblies are achiral, pinwheel superlattices become strongly mirror asymmetric on solid substrates as demonstrated by chirality measures. Liquid-phase transmission electron microscopy and computational models show that van der Waals and electrostatic interactions between nanoparticles control thermodynamic equilibrium. Variable corner-to-edge connections among tetrahedra enable fine-tuning of chirality. The domains of the bilayer superlattices show strong chiroptical activity as identified by photon-induced near-field electron microscopy and finite-difference time-domain simulations. The simplicity and versatility of substrate-supported chiral superlattices facilitate the manufacture of metastructured coatings with unusual optical, mechanical and electronic characteristics.


Asunto(s)
Oro , Nanopartículas del Metal , Electrónica , Física
3.
Nature ; 591(7849): 317-321, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33505026

RESUMEN

METTL3 (methyltransferase-like 3) mediates the N6-methyladenosine (m6A) methylation of mRNA, which affects the stability of mRNA and its translation into protein1. METTL3 also binds chromatin2-4, but the role of METTL3 and m6A methylation in chromatin is not fully understood. Here we show that METTL3 regulates mouse embryonic stem-cell heterochromatin, the integrity of which is critical for silencing retroviral elements and for mammalian development5. METTL3 predominantly localizes to the intracisternal A particle (IAP)-type family of endogenous retroviruses. Knockout of Mettl3 impairs the deposition of multiple heterochromatin marks onto METTL3-targeted IAPs, and upregulates IAP transcription, suggesting that METTL3 is important for the integrity of IAP heterochromatin. We provide further evidence that RNA transcripts derived from METTL3-bound IAPs are associated with chromatin and are m6A-methylated. These m6A-marked transcripts are bound by the m6A reader YTHDC1, which interacts with METTL3 and in turn promotes the association of METTL3 with chromatin. METTL3 also interacts physically with the histone 3 lysine 9 (H3K9) tri-methyltransferase SETDB1 and its cofactor TRIM28, and is important for their localization to IAPs. Our findings demonstrate that METTL3-catalysed m6A modification of RNA is important for the integrity of IAP heterochromatin in mouse embryonic stem cells, revealing a mechanism of heterochromatin regulation in mammals.


Asunto(s)
Ensamble y Desensamble de Cromatina , Heterocromatina/genética , Heterocromatina/metabolismo , Metiltransferasas/metabolismo , Células Madre Embrionarias de Ratones/metabolismo , Animales , Retrovirus Endógenos/genética , Regulación de la Expresión Génica , Genes de Partícula A Intracisternal/genética , N-Metiltransferasa de Histona-Lisina/metabolismo , Histonas/química , Histonas/metabolismo , Ratones , Proteína 28 que Contiene Motivos Tripartito/metabolismo
4.
Proc Natl Acad Sci U S A ; 121(3): e2308812120, 2024 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-38190540

RESUMEN

Aging in an individual refers to the temporal change, mostly decline, in the body's ability to meet physiological demands. Biological age (BA) is a biomarker of chronological aging and can be used to stratify populations to predict certain age-related chronic diseases. BA can be predicted from biomedical features such as brain MRI, retinal, or facial images, but the inherent heterogeneity in the aging process limits the usefulness of BA predicted from individual body systems. In this paper, we developed a multimodal Transformer-based architecture with cross-attention which was able to combine facial, tongue, and retinal images to estimate BA. We trained our model using facial, tongue, and retinal images from 11,223 healthy subjects and demonstrated that using a fusion of the three image modalities achieved the most accurate BA predictions. We validated our approach on a test population of 2,840 individuals with six chronic diseases and obtained significant difference between chronological age and BA (AgeDiff) than that of healthy subjects. We showed that AgeDiff has the potential to be utilized as a standalone biomarker or conjunctively alongside other known factors for risk stratification and progression prediction of chronic diseases. Our results therefore highlight the feasibility of using multimodal images to estimate and interrogate the aging process.


Asunto(s)
Envejecimiento , Suministros de Energía Eléctrica , Humanos , Cara , Biomarcadores , Enfermedad Crónica
5.
Proc Natl Acad Sci U S A ; 121(19): e2313590121, 2024 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-38683978

RESUMEN

Myokines and exosomes, originating from skeletal muscle, are shown to play a significant role in maintaining brain homeostasis. While exercise has been reported to promote muscle secretion, little is known about the effects of neuronal innervation and activity on the yield and molecular composition of biologically active molecules from muscle. As neuromuscular diseases and disabilities associated with denervation impact muscle metabolism, we hypothesize that neuronal innervation and firing may play a pivotal role in regulating secretion activities of skeletal muscles. We examined this hypothesis using an engineered neuromuscular tissue model consisting of skeletal muscles innervated by motor neurons. The innervated muscles displayed elevated expression of mRNAs encoding neurotrophic myokines, such as interleukin-6, brain-derived neurotrophic factor, and FDNC5, as well as the mRNA of peroxisome-proliferator-activated receptor γ coactivator 1α, a key regulator of muscle metabolism. Upon glutamate stimulation, the innervated muscles secreted higher levels of irisin and exosomes containing more diverse neurotrophic microRNAs than neuron-free muscles. Consequently, biological factors secreted by innervated muscles enhanced branching, axonal transport, and, ultimately, spontaneous network activities of primary hippocampal neurons in vitro. Overall, these results reveal the importance of neuronal innervation in modulating muscle-derived factors that promote neuronal function and suggest that the engineered neuromuscular tissue model holds significant promise as a platform for producing neurotrophic molecules.


Asunto(s)
Factor Neurotrófico Derivado del Encéfalo , Exosomas , Músculo Esquelético , Exosomas/metabolismo , Animales , Músculo Esquelético/metabolismo , Músculo Esquelético/inervación , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Ratones , Fibronectinas/metabolismo , Neuronas Motoras/metabolismo , Interleucina-6/metabolismo , MicroARNs/metabolismo , MicroARNs/genética , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma/metabolismo , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma/genética , Neuronas/metabolismo , Factores de Crecimiento Nervioso/metabolismo , Mioquinas
6.
Nature ; 575(7782): 361-365, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31695197

RESUMEN

Reprogramming of mitochondria provides cells with the metabolic flexibility required to adapt to various developmental transitions such as stem cell activation or immune cell reprogramming, and to respond to environmental challenges such as those encountered under hypoxic conditions or during tumorigenesis1-3. Here we show that the i-AAA protease YME1L rewires the proteome of pre-existing mitochondria in response to hypoxia or nutrient starvation. Inhibition of mTORC1 induces a lipid signalling cascade via the phosphatidic acid phosphatase LIPIN1, which decreases phosphatidylethanolamine levels in mitochondrial membranes and promotes proteolysis. YME1L degrades mitochondrial protein translocases, lipid transfer proteins and metabolic enzymes to acutely limit mitochondrial biogenesis and support cell growth. YME1L-mediated mitochondrial reshaping supports the growth of pancreatic ductal adenocarcinoma (PDAC) cells as spheroids or xenografts. Similar changes to the mitochondrial proteome occur in the tumour tissues of patients with PDAC, suggesting that YME1L is relevant to the pathophysiology of these tumours. Our results identify the mTORC1-LIPIN1-YME1L axis as a post-translational regulator of mitochondrial proteostasis at the interface between metabolism and mitochondrial dynamics.


Asunto(s)
ATPasas Asociadas con Actividades Celulares Diversas/metabolismo , Metabolismo de los Lípidos , Metaloendopeptidasas/metabolismo , Mitocondrias/metabolismo , Proteínas Mitocondriales/metabolismo , ATPasas Asociadas con Actividades Celulares Diversas/genética , Hipoxia de la Célula , Línea Celular , Proliferación Celular , Humanos , Lípidos , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Metaloendopeptidasas/genética , Proteínas Mitocondriales/genética , Proteolisis
7.
Nucleic Acids Res ; 51(22): 12381-12396, 2023 Dec 11.
Artículo en Inglés | MEDLINE | ID: mdl-37930830

RESUMEN

Anti-CRISPR (Acr) proteins are encoded by mobile genetic elements to overcome the CRISPR immunity of prokaryotes, displaying promises as controllable tools for modulating CRISPR-based applications. However, characterizing novel anti-CRISPR proteins and exploiting Acr-related technologies is a rather long and tedious process. Here, we established a versatile plasmid interference with CRISPR interference (PICI) system in Escherichia coli for rapidly characterizing Acrs and developing Acr-based technologies. Utilizing the PICI system, we discovered two novel type II-A Acrs (AcrIIA33 and AcrIIA34), which can inhibit the activity of SpyCas9 by affecting DNA recognition of Cas9. We further constructed a circularly permuted AcrIIA4 (cpA4) protein and developed optogenetically engineered, robust AcrIIA4 (OPERA4) variants by combining cpA4 with the light-oxygen-voltage 2 (LOV2) blue light sensory domain. OPERA4 variants are robust light-dependent tools for controlling the activity of SpyCas9 by approximately 1000-fold change under switching dark-light conditions in prokaryotes. OPERA4 variants can achieve potent light-controllable genome editing in human cells as well. Together, our work provides a versatile screening system for characterizing Acrs and developing the Acr-based controllable tools.


Asunto(s)
Proteína 9 Asociada a CRISPR , Sistemas CRISPR-Cas , Humanos , Proteína 9 Asociada a CRISPR/genética , Sistemas CRISPR-Cas/genética , Edición Génica , Plásmidos/genética , Proteínas Bacterianas/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo
8.
Lancet ; 402(10399): 373-385, 2023 07 29.
Artículo en Inglés | MEDLINE | ID: mdl-37311468

RESUMEN

BACKGROUND: Erythropoiesis-stimulating agents (ESAs) are the standard-of-care treatment for anaemia in most patients with lower-risk myelodysplastic syndromes but responses are limited and transient. Luspatercept promotes late-stage erythroid maturation and has shown durable clinical efficacy in patients with lower-risk myelodysplastic syndromes. In this study, we report the results of a prespecified interim analysis of luspatercept versus epoetin alfa for the treatment of anaemia due to lower-risk myelodysplastic syndromes in the phase 3 COMMANDS trial. METHODS: The phase 3, open-label, randomised controlled COMMANDS trial is being conducted at 142 sites in 26 countries. Eligible patients were aged 18 years or older, had a diagnosis of myelodysplastic syndromes of very low risk, low risk, or intermediate risk (per the Revised International Prognostic Scoring System), were ESA-naive, and required red blood cell transfusions (2-6 packed red blood cell units per 8 weeks for ≥8 weeks immediately before randomisation). Integrated response technology was used to randomly assign patients (1:1, block size 4) to luspatercept or epoetin alfa, stratified by baseline red blood cell transfusion burden (<4 units per 8 weeks vs ≥4 units per 8 weeks), endogenous serum erythropoietin concentration (≤200 U/L vs >200 to <500 U/L), and ring sideroblast status (positive vs negative). Luspatercept was administered subcutaneously once every 3 weeks starting at 1·0 mg/kg body weight with possible titration up to 1·75 mg/kg. Epoetin alfa was administered subcutaneously once a week starting at 450 IU/kg body weight with possible titration up to 1050 IU/kg (maximum permitted total dose of 80 000 IU). The primary endpoint was red blood cell transfusion independence for at least 12 weeks with a concurrent mean haemoglobin increase of at least 1·5 g/dL (weeks 1-24), assessed in the intention-to-treat population. Safety was assessed in patients who received at least one dose of study treatment. The COMMANDS trial was registered with ClinicalTrials.gov, NCT03682536 (active, not recruiting). FINDINGS: Between Jan 2, 2019 and Aug 31, 2022, 356 patients were randomly assigned to receive luspatercept (178 patients) or epoetin alfa (178 patients), comprising 198 (56%) men and 158 (44%) women (median age 74 years [IQR 69-80]). The interim efficacy analysis was done for 301 patients (147 in the luspatercept group and 154 in the epoetin alfa group) who completed 24 weeks of treatment or discontinued earlier. 86 (59%) of 147 patients in the luspatercept group and 48 (31%) of 154 patients in the epoetin alfa group reached the primary endpoint (common risk difference on response rate 26·6; 95% CI 15·8-37·4; p<0·0001). Median treatment exposure was longer for patients receiving luspatercept (42 weeks [IQR 20-73]) versus epoetin alfa (27 weeks [19-55]). The most frequently reported grade 3 or 4 treatment-emergent adverse events with luspatercept (≥3% patients) were hypertension, anaemia, dyspnoea, neutropenia, thrombocytopenia, pneumonia, COVID-19, myelodysplastic syndromes, and syncope; and with epoetin alfa were anaemia, pneumonia, neutropenia, hypertension, iron overload, COVID-19 pneumonia, and myelodysplastic syndromes. The most common suspected treatment-related adverse events in the luspatercept group (≥3% patients, with the most common event occurring in 5% patients) were fatigue, asthenia, nausea, dyspnoea, hypertension, and headache; and none (≥3% patients) in the epoetin alfa group. One death after diagnosis of acute myeloid leukaemia was considered to be related to luspatercept treatment (44 days on treatment). INTERPRETATION: In this interim analysis, luspatercept improved the rate at which red blood cell transfusion independence and increased haemoglobin were achieved compared with epoetin alfa in ESA-naive patients with lower-risk myelodysplastic syndromes. Long-term follow-up and additional data will be needed to confirm these results and further refine findings in other subgroups of patients with lower-risk myelodysplastic syndromes, including non-mutated SF3B1 or ring sideroblast-negative subgroups. FUNDING: Celgene and Acceleron Pharma.


Asunto(s)
Anemia , COVID-19 , Hematínicos , Hipertensión , Síndromes Mielodisplásicos , Neutropenia , Masculino , Humanos , Femenino , Anciano , Epoetina alfa/efectos adversos , Hematínicos/efectos adversos , Eritropoyesis , Anemia/tratamiento farmacológico , Anemia/etiología , Hipertensión/tratamiento farmacológico , Síndromes Mielodisplásicos/complicaciones , Síndromes Mielodisplásicos/tratamiento farmacológico , Síndromes Mielodisplásicos/inducido químicamente , Hemoglobinas/uso terapéutico , Disnea/tratamiento farmacológico , Peso Corporal
9.
Biochem Biophys Res Commun ; 721: 150003, 2024 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-38772212

RESUMEN

BACKGROUND: In recent years, the incidence rate of nonalcoholic fatty liver disease (NAFLD) has ascended with the increasing number of metabolic diseases such as obesity and diabetes, which will bring great medical burden to society. At present, multiple scientific experiments have found that the CCR4-NOT complex can participate in regulating obesity and energy metabolism. This study is designed to explore the role and mechanism of CCR4-NOT transcription complex subunit 7 (CNOT7), a subunit of the CCR4-NOT complex in liver lipid deposition. METHODS: To establish the NAFLD cell model, palmitic acid (PA) was utilized to stimulate HepG2 cells and LO2 cells, promoting intracellular lipid deposition. CNOT7 was knockdown by siRNA and lentivirus to evaluate the effect of CNOT7 in NAFLD. RESULTS: Our results demonstrated that the expression of CNOT7 was increased in the NAFLD cell model. After knocking down CNOT7, the lipid deposition declined in HepG2 or LO2 cells treated by PA reduced. We found the lipid synthesis genes and the lipid uptake and transport factors in the CNOT7 knockdown group were significantly downregulated compared to the non-knockdown group. Furthermore, knockdown of CNOT7 might promote fatty acid oxidation. CONCLUSION: Knocking down CNOT7 can improve lipid deposition and CNOT7 may be a potential therapeutic target for NAFLD.


Asunto(s)
Metabolismo de los Lípidos , Enfermedad del Hígado Graso no Alcohólico , Humanos , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Enfermedad del Hígado Graso no Alcohólico/patología , Enfermedad del Hígado Graso no Alcohólico/genética , Células Hep G2 , Técnicas de Silenciamiento del Gen , Ácido Palmítico/metabolismo , Proteínas Represoras/metabolismo , Proteínas Represoras/genética , Hígado/metabolismo , Hígado/patología , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Exorribonucleasas
10.
Small ; 20(25): e2308724, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38229571

RESUMEN

In future information storage and processing, magnonics is one of the most promising candidates to replace traditional microelectronics. Yttrium iron garnet (YIG) films with perpendicular magnetic anisotropy (PMA) have aroused widespread interest in magnonics. Obtaining strong PMA in a thick YIG film with a small lattice mismatch (η) has been fascinating but challenging. Here, a novel strategy is proposed to reduce the required minimum strain value for producing PMA and increase the maximum thickness for maintaining PMA in YIG films by slight oxygen deficiency. Strong PMA is achieved in the YIG film with an η of only 0.4% and a film thickness up to 60 nm, representing the strongest PMA for such a small η reported so far. Combining transmission electron microscopy analyses, magnetic measurements, and a theoretical model, it is demonstrated that the enhancement of PMA physically originates from the reduction of saturation magnetization and the increase of magnetostriction coefficient induced by oxygen deficiency. The Gilbert damping values of the 60-nm-thick YIG films with PMA are on the order of 10-4. This strategy improves the flexibility for the practical applications of YIG-based magnonic devices and provides promising insights for the theoretical understanding and the experimental enhancement of PMA in garnet films.

11.
Hepatology ; 78(4): 1200-1208, 2023 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-37080558

RESUMEN

BACKGROUND AND AIMS: The presence of at-risk NASH is associated with an increased risk of cirrhosis and complications. Therefore, noninvasive identification of at-risk NASH with an accurate biomarker is a critical need for pharmacologic therapy. We aim to explore the performance of several magnetic resonance (MR)-based imaging parameters in diagnosing at-risk NASH. APPROACH AND RESULTS: This prospective clinical trial (NCT02565446) includes 104 paired MR examinations and liver biopsies performed in patients with suspected or diagnosed NAFLD. Magnetic resonance elastography-assessed liver stiffness (LS), 6-point Dixon-derived proton density fat fraction (PDFF), and single-point saturation-recovery acquisition-calculated T1 relaxation time were explored. Among all predictors, LS showed the significantly highest accuracy in diagnosing at-risk NASH [AUC LS : 0.89 (0.82, 0.95), AUC PDFF : 0.70 (0.58, 0.81), AUC T1 : 0.72 (0.61, 0.82), z -score test z >1.96 for LS vs any of others]. The optimal cutoff value of LS to identify at-risk NASH patients was 3.3 kPa (sensitivity: 79%, specificity: 82%, negative predictive value: 91%), whereas the optimal cutoff value of T1 was 850 ms (sensitivity: 75%, specificity: 63%, and negative predictive value: 87%). PDFF had the highest performance in diagnosing NASH with any fibrosis stage [AUC PDFF : 0.82 (0.72, 0.91), AUC LS : 0.73 (0.63, 0.84), AUC T1 : 0.72 (0.61, 0.83), |z| <1.96 for all]. CONCLUSION: Magnetic resonance elastography-assessed LS alone outperformed PDFF, and T1 in identifying patients with at-risk NASH for therapeutic trials.


Asunto(s)
Diagnóstico por Imagen de Elasticidad , Enfermedad del Hígado Graso no Alcohólico , Humanos , Diagnóstico por Imagen de Elasticidad/métodos , Hígado/diagnóstico por imagen , Hígado/patología , Cirrosis Hepática/patología , Imagen por Resonancia Magnética/métodos , Enfermedad del Hígado Graso no Alcohólico/complicaciones , Protones , Estudios Prospectivos
12.
Respir Res ; 25(1): 167, 2024 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-38637823

RESUMEN

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a frequently diagnosed yet treatable condition, provided it is identified early and managed effectively. This study aims to develop an advanced COPD diagnostic model by integrating deep learning and radiomics features. METHODS: We utilized a dataset comprising CT images from 2,983 participants, of which 2,317 participants also provided epidemiological data through questionnaires. Deep learning features were extracted using a Variational Autoencoder, and radiomics features were obtained using the PyRadiomics package. Multi-Layer Perceptrons were used to construct models based on deep learning and radiomics features independently, as well as a fusion model integrating both. Subsequently, epidemiological questionnaire data were incorporated to establish a more comprehensive model. The diagnostic performance of standalone models, the fusion model and the comprehensive model was evaluated and compared using metrics including accuracy, precision, recall, F1-score, Brier score, receiver operating characteristic curves, and area under the curve (AUC). RESULTS: The fusion model exhibited outstanding performance with an AUC of 0.952, surpassing the standalone models based solely on deep learning features (AUC = 0.844) or radiomics features (AUC = 0.944). Notably, the comprehensive model, incorporating deep learning features, radiomics features, and questionnaire variables demonstrated the highest diagnostic performance among all models, yielding an AUC of 0.971. CONCLUSION: We developed and implemented a data fusion strategy to construct a state-of-the-art COPD diagnostic model integrating deep learning features, radiomics features, and questionnaire variables. Our data fusion strategy proved effective, and the model can be easily deployed in clinical settings. TRIAL REGISTRATION: Not applicable. This study is NOT a clinical trial, it does not report the results of a health care intervention on human participants.


Asunto(s)
Aprendizaje Profundo , Enfermedad Pulmonar Obstructiva Crónica , Humanos , Área Bajo la Curva , Redes Neurales de la Computación , Enfermedad Pulmonar Obstructiva Crónica/diagnóstico por imagen , Enfermedad Pulmonar Obstructiva Crónica/epidemiología , Curva ROC , Estudios Retrospectivos
13.
Chemistry ; 30(27): e202304118, 2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38433408

RESUMEN

New chiral ligands could be obtained by introducing proline moieties and imidazoline moieties to binaphthyl skeletons. The chiral ligands exhibited balanced rigidity and flexibility which could allow the change of the conformations during the reactions on one hand, and could provide sufficient asymmetric induction on the other. The proline moiety could act as a linker connecting the binaphthyl skeletons and the imidazoline moieties as well as a coordinating group for the central metal, and the electronic and steric properties of the imidazoline groups could be carefully fine-tuned by the use of different substituents. In the presence of Cu(II) catalyst bearing such chiral ligands, aza-Friedel-Crafts reaction of 1-naphthols and electron-rich phenols with isatin-derived ketimines provided the desired products with good to excellent yields and up to 99 % ee. The reactions showed good scalability, and excellent ee could still be obtained when the reaction was carried out in gram-scale.

14.
BMC Cancer ; 24(1): 101, 2024 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-38233802

RESUMEN

BACKGROUND: Vulvar and vaginal melanoma (VuM & VaM) is a rare gynecologic malignancy with high mortality but low effectiveness to checkpoint immunotherapy compared to cutaneous melanoma. This article aims to elucidate the role of the disordered immune microenvironment in cancer progression in VuM. METHODS: At first, this article applied single-cell RNA sequencing (scRNA-seq) to the VuM obtained from a 68-year-old female patient, and constructed a single-cell atlas of VuM consist of 12,243 single cells. Then this article explores the genomic complexity and core signal channel in VuM microenvironment. RESULTS: This article provides new insights about the pathogenesis of VuM based on single-cell resolution data. It was found that the activation of CD8+ T cell contributed to induce tumor angiogenesis and immune escape, and the activation of the antigen-presenting molecular function participated in melanoma metastasis. CONCLUSION: This article provided new insights into underlining VuM molecular regulation and potential signaling involved in immunotherapy, which would benefit the clinical practice and administration.


Asunto(s)
Melanoma , Neoplasias Cutáneas , Neoplasias de la Vulva , Femenino , Humanos , Anciano , Melanoma/terapia , Neoplasias de la Vulva/terapia , Análisis de la Célula Individual , Inmunoterapia , Microambiente Tumoral
15.
J Magn Reson Imaging ; 2024 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-38935749

RESUMEN

BACKGROUND: MR elastography (MRE) at 60 Hz is widely used for staging liver fibrosis. MRE with lower frequencies may provide inflammation biomarkers. PURPOSE: To establish a practical simultaneous dual-frequency liver MRE protocol at both 30 Hz and 60 Hz during a single examination and validate the occurrence of second harmonic waves at 30 Hz. STUDY TYPE: Retrospective. SUBJECTS: One hundred six patients (48 females, age: 50.0 ± 13.4 years) were divided as follows: Cohort One (15 patients with chronic liver disease [CLD] and 25 healthy volunteers) with simultaneous dual-frequency MRE. Cohort Two (66 patients with CLD) with second harmonic MRE. FIELD STRENGTH/SEQUENCE: 3-T, single- or dual-frequency MRE at 30 Hz and 60 Hz. ASSESSMENT: Liver stiffness (LS) in both cohorts was evaluated with manually placed volumetric ROIs by two independent analyzers. Image quality was assessed by three independent readers on a 4-point scale (0-3: none/failed, fair, moderate, excellent) based on the depth of wave propagation with 1/3 incremental penetration. The success rate was derived from the percentage of nonzero quality scores. STATISTICAL TESTS: Measurement agreement, bias, and repeatability of LS were assessed using intraclass correlation coefficients (ICCs), Bland-Altman plots, and repeatability coefficient (RC). Mann-Whitney U tests were used to evaluate the differences in image quality between different methods. A P-value <0.05 was considered statistically significant. RESULTS: Success rate was 97.5% in Cohort One and 91% success rate for the second harmonic MRE in Cohort Two. The second harmonic and conventional MRE showed excellent agreement in LS (all ICCs >0.90). The quality scores for the second harmonic wave images were lower than those from the conventional MRE (Z = -4.523). DATA CONCLUSION: Compared with conventional and second harmonic methods, simultaneous dual-frequency had better image quality, high success rate and the advantage of intrinsic co-registration, while the second harmonic method can be an alternative if custom waveform is not available. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 1.

16.
Mol Pharm ; 21(6): 2922-2936, 2024 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-38751169

RESUMEN

With the increased prevalence of nonalcoholic steatohepatitis (NASH) in the world, effective pharmacotherapy in clinical practice is still lacking. Previous studies have shown that dibenzazepine (DBZ), a Notch inhibitor, could alleviate NASH development in a mouse model. However, low bioavailability, poor water solubility, and extrahepatic side effects restrict its clinical application. To overcome these barriers, we developed a reactive oxygen species (ROS)-sensitive nanoparticle based on the conjugation of bilirubin to poly(ethylene glycol) (PEG) chains, taking into account the overaccumulation of hepatic ROS in the pathologic state of nonalcoholic steatohepatitis (NASH). The PEGylated bilirubin can self-assemble into nanoparticles in an aqueous solution and encapsulate insoluble DBZ into its hydrophobic cavity. DBZ nanoparticles (DBZ Nps) had good stability, rapidly released DBZ in response to H2O2, and effectively scavenged intracellular ROS of hepatocytes. After systemic administration, DBZ Nps could accumulate in the liver of the NASH mice, extend persistence in circulation, and improve the bioavailability of DBZ. Furthermore, DBZ Nps significantly improved glucose intolerance, relieved hepatic lipid accumulation and inflammation, and ameliorated NASH-induced liver fibrosis. Additionally, DBZ Nps had no significant extrahepatic side effects. Taken together, our results highlight the potential of the ROS-sensitive DBZ nanoparticle as a promising therapeutic strategy for NASH.


Asunto(s)
Lipogénesis , Hígado , Ratones Endogámicos C57BL , Nanopartículas , Enfermedad del Hígado Graso no Alcohólico , Especies Reactivas de Oxígeno , Animales , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Ratones , Nanopartículas/química , Lipogénesis/efectos de los fármacos , Masculino , Hígado/metabolismo , Hígado/efectos de los fármacos , Hígado/patología , Receptores Notch/metabolismo , Receptores Notch/antagonistas & inhibidores , Humanos , Inflamación/tratamiento farmacológico , Inflamación/metabolismo , Bilirrubina , Polietilenglicoles/química , Modelos Animales de Enfermedad , Hepatocitos/metabolismo , Hepatocitos/efectos de los fármacos , Dibenzazepinas
17.
Cell Biol Int ; 48(4): 510-520, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38225684

RESUMEN

Acute lung injury (ALI) is a severe disease with high mortality and poor prognosis, characterized by excessive and uncontrolled inflammatory response. Vascular endothelial growth factor A (VEGF-A) contributes to the development and progression of ALI. The aim of this study was to evaluate the role of glucose transporter 1 (GLUT1) in alveolar epithelial VEGF-A production in lipopolysaccharide (LPS)-induced ALI. An ALI mouse model was induced by LPS oropharyngeal instillation. Mice were challenged with LPS and then treated with WZB117, a specific antagonist of GLUT1. For the vitro experiments, cultured A549 cells (airway epithelial cell line) were exposed to LPS, with or without the GLUT1 inhibitors WZB117 or BAY876. LPS significantly upregulated of GLUT1 and VEGF-A both in the lung from ALI mice and in cultured A549. In vivo, treatment with WZB117 not only markedly decreased LPS-induced pulmonary edema, injury, neutrophilia, as well as levels of interleukin (IL)-1ß, IL-6 and tumor necrosis factor-α in bronchoalveolar lavage fluid (BALF), but also reduced VEGF-A production. Yet, the maximum tolerated concentration of WZB117 failed to suppress LPS-induced VEGF-A overexpression in vitro. While administration of BAY876 inhibited gene and protein expression as well as secretion of VEGF-A in response to LPS in A549. These results illustrated that GLUT1 upregulates VEGF-A production in alveolar epithelia from LPS-induced ALI, and inhibition of GLUT1 alleviates ALI.


Asunto(s)
Lesión Pulmonar Aguda , Hidroxibenzoatos , Lipopolisacáridos , Ratones , Animales , Lipopolisacáridos/toxicidad , Factor A de Crecimiento Endotelial Vascular/metabolismo , Transportador de Glucosa de Tipo 1 , Lesión Pulmonar Aguda/metabolismo , Pulmón/metabolismo , Epitelio/metabolismo
18.
Environ Sci Technol ; 58(4): 2058-2068, 2024 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-38230546

RESUMEN

Substituted polycyclic aromatic hydrocarbons (sub-PAHs) are receiving increased attention due to their high toxicity and ubiquitous presence. However, the accumulation behaviors of sub-PAHs in crop roots remain unclear. In this study, the accumulation mechanism of sub-PAHs in crop roots was systematically disclosed by hydroponic experiments from the perspectives of utilization, uptake, and elimination. The obtained results showed an interesting phenomenon that despite not having the strongest hydrophobicity among the five sub-PAHs, nitro-PAHs (including 9-nitroanthracene and 1-nitropyrene) displayed the strongest accumulation potential in the roots of legume plants, including mung bean and soybean. The nitrogen-deficient experiments, inhibitor experiments, and transcriptomics analysis reveal that nitro-PAHs could be utilized by legumes as a nitrogen source, thus being significantly absorbed by active transport, which relies on amino acid transporters driven by H+-ATPase. Molecular docking simulation further demonstrates that the nitro group is a significant determinant of interaction with an amino acid transporter. Moreover, the depuration experiments indicate that the nitro-PAHs may enter the root cells, further slowing their elimination rates and enhancing the accumulation potential in legume roots. Our results shed light on a previously unappreciated mechanism for root accumulation of sub-PAHs, which may affect their biogeochemical processes in soils.


Asunto(s)
Fabaceae , Hidrocarburos Policíclicos Aromáticos , Fabaceae/metabolismo , Simulación del Acoplamiento Molecular , Raíces de Plantas/química , Raíces de Plantas/metabolismo , Plantas/metabolismo , Nitrógeno/metabolismo
19.
J Immunol ; 209(5): 916-925, 2022 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-35922064

RESUMEN

Thymocytes need to proliferate into a significant cell mass to allow a subsequent selection process during the double-positive (DP) stage. However, it is not clear at what stage this massive cell proliferation occurs. Immature CD8 single-positive (ISP) cells are a well-defined thymocyte subpopulation. However, the function of this cell subset has not yet been characterized. In this study, we analyzed the transcription pattern of mouse ISP cells and observed higher expression levels of cell cycling genes. We also found out that ISP cells exhibited the highest cell proliferative capacity among thymocytes in different developmental stages. Nuclear protein ataxia-telangiectasia (NPAT/p220) is one of the highly expressed cell cycling genes in ISP cells, which is known to play a critical role in coordinating histone gene expression necessary for rapid cell proliferation. Selective deletion of NPAT at the ISP stage led to reduced thymus size and significant loss of DP cells, secondary to reduced histone gene expression and impaired ISP cell proliferation capacity. A block of thymocyte development at the ISP stage was also observed, which was due to increased IL-7R expression. Continuous IL-7R signal served as a compensating mechanism for cell proliferation upon NPAT deletion, but in turn inhibited the expression of transcription factors TCF-1 and LEF-1, which is essential for the transition of ISP to DP cells. In summary, our study revealed the proliferation capacity of the ISP subpopulation during thymocyte differentiation as well as a vital role of NPAT in this developmental stage.


Asunto(s)
Histonas , Timocitos , Animales , Linfocitos T CD8-positivos/metabolismo , Proteínas de Ciclo Celular , Diferenciación Celular , Proliferación Celular , Histonas/metabolismo , Ratones , Proteínas Nucleares/metabolismo , Timocitos/metabolismo , Timo/metabolismo
20.
Cost Eff Resour Alloc ; 22(1): 8, 2024 Jan 27.
Artículo en Inglés | MEDLINE | ID: mdl-38281053

RESUMEN

BACKGROUND: Combined serplulimab and chemotherapy demonstrated improved clinical survival outcomes in patients with advanced esophageal squamous cell carcinoma (ESCC) and PD-L1 combined positive scores (CPS) ≥ 1. The present study aimed to evaluate the economic viability of integrating serplulimab in combination with chemotherapy as a potential therapeutic approach for treating ESCC in China. METHODS: A Markov model was constructed to evaluate the economic and health-related implications of combining serplulimab with chemotherapy. With the incremental cost-effectiveness ratio (ICER), costs and results in terms of health were estimated. For assessing parameter uncertainty, one-way and probabilistic sensitivity studies were carried out. RESULTS: The combination of serplulimab and chemotherapy yielded incremental costs and QALYs of $3,163 and 0.14, $2,418 and 0.10, and $3,849 and 0.15, respectively, for the overall population as well as patients with PD-L1 CPS1-10 and PD-L1 CPS ≥ 10. This corresponds to ICER values per QALY of $23,657, $23,982, and $25,134. At the prespecified WTP limit, the probabilities of serplulimab with chemotherapy being the preferred intervention option were 74.4%, 61.3%, and 78.1% for the entire patient population, those with PD-L1 1 ≤ CPS < 10, and those with PD-L1 CPS ≥ 10, respectively. The stability of the presented model was confirmed through sensitivity studies. CONCLUSIONS: In conclusion, the combination of Serplulimab and chemotherapy showed excellent cost-effectiveness compared to chemotherapy alone in treating PD-L1-positive patients with ESCC in China.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA