Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.638
Filtrar
Más filtros

Bases de datos
Tipo del documento
Intervalo de año de publicación
1.
Genes Dev ; 37(19-20): 865-882, 2023 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-37852796

RESUMEN

The MYC oncogenic transcription factor is acetylated by the p300 and GCN5 histone acetyltransferases. The significance of MYC acetylation and the functions of specific acetylated lysine (AcK) residues have remained unclear. Here, we show that the major p300-acetylated K148(149) and K157(158) sites in human (or mouse) MYC and the main GCN5-acetylated K323 residue are reversibly acetylated in various malignant and nonmalignant cells. Oncogenic overexpression of MYC enhances its acetylation and alters the regulation of site-specific acetylation by proteasome and deacetylase inhibitors. Acetylation of MYC at different K residues differentially affects its stability in a cell type-dependent manner. Lysine-to-arginine substitutions indicate that although none of the AcK residues is required for MYC stimulation of adherent cell proliferation, individual AcK sites have gene-specific functions controlling select MYC-regulated processes in cell adhesion, contact inhibition, apoptosis, and/or metabolism and are required for the malignant cell transformation activity of MYC. Each AcK site is required for anchorage-independent growth of MYC-overexpressing cells in vitro, and both the AcK148(149) and AcK157(158) residues are also important for the tumorigenic activity of MYC transformed cells in vivo. The MYC AcK site-specific signaling pathways identified may offer new avenues for selective therapeutic targeting of MYC oncogenic activities.


Asunto(s)
Histona Acetiltransferasas , Lisina , Animales , Humanos , Ratones , Acetilación , Adhesión Celular/genética , Proliferación Celular/genética , Transformación Celular Neoplásica/genética , Histona Acetiltransferasas/metabolismo , Lisina/metabolismo
2.
Nature ; 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38926583

RESUMEN

The current technologies to place new DNA into specific locations in plant genomes are low frequency and error-prone, and this inefficiency hampers genome-editing approaches to develop improved crops1,2. Often considered to be genome 'parasites', transposable elements (TEs) evolved to insert their DNA seamlessly into genomes3-5. Eukaryotic TEs select their site of insertion based on preferences for chromatin contexts, which differ for each TE type6-9. Here we developed a genome engineering tool that controls the TE insertion site and cargo delivered, taking advantage of the natural ability of the TE to precisely excise and insert into the genome. Inspired by CRISPR-associated transposases that target transposition in a programmable manner in bacteria10-12, we fused the rice Pong transposase protein to the Cas9 or Cas12a programmable nucleases. We demonstrated sequence-specific targeted insertion (guided by the CRISPR gRNA) of enhancer elements, an open reading frame and a gene expression cassette into the genome of the model plant Arabidopsis. We then translated this system into soybean-a major global crop in need of targeted insertion technology. We have engineered a TE 'parasite' into a usable and accessible toolkit that enables the sequence-specific targeting of custom DNA into plant genomes.

3.
Nature ; 615(7954): 823-829, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36991190

RESUMEN

Neural networks based on memristive devices1-3 have the ability to improve throughput and energy efficiency for machine learning4,5 and artificial intelligence6, especially in edge applications7-21. Because training a neural network model from scratch is costly in terms of hardware resources, time and energy, it is impractical to do it individually on billions of memristive neural networks distributed at the edge. A practical approach would be to download the synaptic weights obtained from the cloud training and program them directly into memristors for the commercialization of edge applications. Some post-tuning in memristor conductance could be done afterwards or during applications to adapt to specific situations. Therefore, in neural network applications, memristors require high-precision programmability to guarantee uniform and accurate performance across a large number of memristive networks22-28. This requires many distinguishable conductance levels on each memristive device, not only laboratory-made devices but also devices fabricated in factories. Analog memristors with many conductance states also benefit other applications, such as neural network training, scientific computing and even 'mortal computing'25,29,30. Here we report 2,048 conductance levels achieved with memristors in fully integrated chips with 256 × 256 memristor arrays monolithically integrated on complementary metal-oxide-semiconductor (CMOS) circuits in a commercial foundry. We have identified the underlying physics that previously limited the number of conductance levels that could be achieved in memristors and developed electrical operation protocols to avoid such limitations. These results provide insights into the fundamental understanding of the microscopic picture of memristive switching as well as approaches to enable high-precision memristors for various applications. Fig. 1 HIGH-PRECISION MEMRISTOR FOR NEUROMORPHIC COMPUTING.: a, Proposed scheme of the large-scale application of memristive neural networks for edge computing. Neural network training is performed in the cloud. The obtained weights are downloaded and accurately programmed into a massive number of memristor arrays distributed at the edge, which imposes high-precision requirements on memristive devices. b, An eight-inch wafer with memristors fabricated by a commercial semiconductor manufacturer. c, High-resolution transmission electron microscopy image of the cross-section view of a memristor. Pt and Ta serve as the bottom electrode (BE) and top electrode (TE), respectively. Scale bars, 1 µm and 100 nm (inset). d, Magnification of the memristor material stack. Scale bar, 5 nm. e, As-programmed (blue) and after-denoising (red) currents of a memristor are read by a constant voltage (0.2 V). The denoising process eliminated the large-amplitude RTN observed in the as-programmed state (see Methods). f, Magnification of three nearest-neighbour states after denoising. The current of each state was read by a constant voltage (0.2 V). No large-amplitude RTN was observed, and all of the states can be clearly distinguished. g, An individual memristor on the chip was tuned into 2,048 resistance levels by high-resolution off-chip driving circuitry, and each resistance level was read by a d.c. voltage sweeping from 0 to 0.2 V. The target resistance was set from 50 µS to 4,144 µS with a 2-µS interval between neighbouring levels. All readings at 0.2 V are less than 1 µS from the target conductance. Bottom inset, magnification of the resistance levels. Top inset, experimental results of an entire 256 × 256 array programmed by its 6-bit on-chip circuitry into 64 32 × 32 blocks, and each block is programmed into one of the 64 conductance levels. Each of the 256 × 256 memristors has been previously switched over one million cycles, demonstrating the high endurance and robustness of the devices.

4.
PLoS Pathog ; 20(3): e1012128, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38547254

RESUMEN

Porcine reproductive and respiratory syndrome virus (PRRSV) is known to suppress the type I interferon (IFNs-α/ß) response during infection. PRRSV also activates the NF-κB signaling pathway, leading to the production of proinflammatory cytokines during infection. In swine farms, co-infections of PRRSV and other secondary bacterial pathogens are common and exacerbate the production of proinflammatory cytokines, contributing to the porcine respiratory disease complex (PRDC) which is clinically a severe disease. Previous studies identified the non-structural protein 1ß (nsp1ß) of PRRSV-2 as an IFN antagonist and the nucleocapsid (N) protein as the NF-κB activator. Further studies showed the leucine at position 126 (L126) of nsp1ß as the essential residue for IFN suppression and the region spanning the nuclear localization signal (NLS) of N as the NF-κB activation domain. In the present study, we generated a double-mutant PRRSV-2 that contained the L126A mutation in the nsp1ß gene and the NLS mutation (ΔNLS) in the N gene using reverse genetics. The immunological phenotype of this mutant PRRSV-2 was examined in porcine alveolar macrophages (PAMs) in vitro and in young pigs in vivo. In PAMs, the double-mutant virus did not suppress IFN-ß expression but decreased the NF-κB-dependent inflammatory cytokine productions compared to those for wild-type PRRSV-2. Co-infection of PAMs with the mutant PRRSV-2 and Streptococcus suis (S. suis) also reduced the production of NF-κB-directed inflammatory cytokines. To further examine the cytokine profiles and the disease severity by the mutant virus in natural host animals, 6 groups of pigs, 7 animals per group, were used for co-infection with the mutant PRRSV-2 and S. suis. The double-mutant PRRSV-2 was clinically attenuated, and the expressions of proinflammatory cytokines and chemokines were significantly reduced in pigs after bacterial co-infection. Compared to the wild-type PRRSV-2 and S. suis co-infection control, pigs coinfected with the double-mutant PRRSV-2 exhibited milder clinical signs, lower titers and shorter duration of viremia, and lower expression of proinflammatory cytokines. In conclusion, our study demonstrates that genetic modification of the type I IFN suppression and NF-κB activation functions of PRRSV-2 may allow us to design a novel vaccine candidate to alleviate the clinical severity of PRRS-2 and PRDC during bacterial co-infection.


Asunto(s)
Coinfección , Interferón Tipo I , Síndrome Respiratorio y de la Reproducción Porcina , Virus del Síndrome Respiratorio y Reproductivo Porcino , Porcinos , Animales , Virus del Síndrome Respiratorio y Reproductivo Porcino/metabolismo , Citocinas/genética , Citocinas/metabolismo , FN-kappa B/genética , FN-kappa B/metabolismo , Macrófagos Alveolares/metabolismo , Interferón Tipo I/metabolismo , Síndrome Respiratorio y de la Reproducción Porcina/genética , Síndrome Respiratorio y de la Reproducción Porcina/metabolismo
5.
Proc Natl Acad Sci U S A ; 120(7): e2206797120, 2023 02 14.
Artículo en Inglés | MEDLINE | ID: mdl-36757889

RESUMEN

Genetic studies have identified ≥240 loci associated with the risk of type 2 diabetes (T2D), yet most of these loci lie in non-coding regions, masking the underlying molecular mechanisms. Recent studies investigating mRNA expression in human pancreatic islets have yielded important insights into the molecular drivers of normal islet function and T2D pathophysiology. However, similar studies investigating microRNA (miRNA) expression remain limited. Here, we present data from 63 individuals, the largest sequencing-based analysis of miRNA expression in human islets to date. We characterized the genetic regulation of miRNA expression by decomposing the expression of highly heritable miRNAs into cis- and trans-acting genetic components and mapping cis-acting loci associated with miRNA expression [miRNA-expression quantitative trait loci (eQTLs)]. We found i) 84 heritable miRNAs, primarily regulated by trans-acting genetic effects, and ii) 5 miRNA-eQTLs. We also used several different strategies to identify T2D-associated miRNAs. First, we colocalized miRNA-eQTLs with genetic loci associated with T2D and multiple glycemic traits, identifying one miRNA, miR-1908, that shares genetic signals for blood glucose and glycated hemoglobin (HbA1c). Next, we intersected miRNA seed regions and predicted target sites with credible set SNPs associated with T2D and glycemic traits and found 32 miRNAs that may have altered binding and function due to disrupted seed regions. Finally, we performed differential expression analysis and identified 14 miRNAs associated with T2D status-including miR-187-3p, miR-21-5p, miR-668, and miR-199b-5p-and 4 miRNAs associated with a polygenic score for HbA1c levels-miR-216a, miR-25, miR-30a-3p, and miR-30a-5p.


Asunto(s)
Diabetes Mellitus Tipo 2 , Islotes Pancreáticos , MicroARNs , Humanos , MicroARNs/metabolismo , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Hemoglobina Glucada , Islotes Pancreáticos/metabolismo , Sitios de Carácter Cuantitativo/genética
6.
Artículo en Inglés | MEDLINE | ID: mdl-38494093

RESUMEN

BACKGROUND: Chronic rhinosinusitis (CRS) is a common inflammatory condition affecting the nasal and paranasal sinus mucosa, often accompanied by olfactory dysfunction. Eosinophilic CRS with nasal polyps (ECRSwNP) is a subtype of CRS characterized by eosinophilic infiltration. Animal models for ECRSwNP with olfactory dysfunction are necessary for exploring potential therapeutic strategies. OBJECTIVE: The aim of this study was to establish a mouse model of ECRSwNP combined with olfactory dysfunction in a shorter time frame using intranasal ovalbumin and Aspergillus protease (AP) administration. The efficacy of the model was validated by evaluating sinonasal inflammation, cytokine levels, olfactory function, and neuroinflammation in the olfactory bulb. METHODS: Male BALB/c mice were intranasally administered ovalbumin and AP for 6 and 12 weeks to induce ECRSwNP. The resultant ECRSwNP mouse model underwent histologic assessment, cytokine analysis of nasal lavage fluid, olfactory behavioral tests, and gene expression profiling to identify neuroinflammatory markers within the olfactory bulb. RESULTS: The developed mouse model exhibited substantial eosinophil infiltration, increased levels of inflammatory cytokines in nasal lavage fluid, and confirmed olfactory dysfunction through behavioral assays. Furthermore, olfactory bulb inflammation and reduced mature olfactory sensory neurons were observed in the model. CONCLUSION: This study successfully established a validated mouse model of ECRSwNP with olfactory dysfunction within a remarkably short span of 6 weeks, providing a valuable tool for investigating the pathogenesis and potential therapies for this condition. The model offers an efficient approach for future research in CRS with nasal polyps and olfactory dysfunction.

7.
BMC Genomics ; 25(1): 600, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38877417

RESUMEN

BACKGROUND: Splicing variants are a major class of pathogenic mutations, with their severity equivalent to nonsense mutations. However, redundant and degenerate splicing signals hinder functional assessments of sequence variations within introns, particularly at branch sites. We have established a massively parallel splicing assay to assess the impact on splicing of 11,191 disease-relevant variants. Based on the experimental results, we then applied regression-based methods to identify factors determining splicing decisions and their respective weights. RESULTS: Our statistical modeling is highly sensitive, accurately annotating the splicing defects of near-exon intronic variants, outperforming state-of-the-art predictive tools. We have incorporated the algorithm and branchpoint information into a web-based tool, SpliceAPP, to provide an interactive application. This user-friendly website allows users to upload any genetic variants with genome coordinates (e.g., chr15 74,687,208 A G), and the tool will output predictions for splicing error scores and evaluate the impact on nearby splice sites. Additionally, users can query branch site information within the region of interest. CONCLUSIONS: In summary, SpliceAPP represents a pioneering approach to screening pathogenic intronic variants, contributing to the development of precision medicine. It also facilitates the annotation of splicing motifs. SpliceAPP is freely accessible using the link https://bc.imb.sinica.edu.tw/SpliceAPP . Source code can be downloaded at https://github.com/hsinnan75/SpliceAPP .


Asunto(s)
Internet , Mutación , Empalme del ARN , Programas Informáticos , Humanos , Algoritmos , Intrones/genética , Sitios de Empalme de ARN/genética , Biología Computacional/métodos
8.
Am J Physiol Endocrinol Metab ; 326(1): E92-E105, 2024 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-38019082

RESUMEN

Zinc is an essential component of the insulin protein complex synthesized in ß cells. The intracellular compartmentalization and distribution of zinc are controlled by 24 transmembrane zinc transporters belonging to the ZnT or Zrt/Irt-like protein (ZIP) family. Downregulation of SLC39A14/ZIP14 has been reported in pancreatic islets of patients with type 2 diabetes (T2D) as well as mouse models of high-fat diet (HFD)- or db/db-induced obesity. Our previous studies observed mild hyperinsulinemia in mice with whole body knockout of Slc39a14 (Zip14 KO). Based on our current secondary data analysis from an integrative single-cell RNA-seq dataset of human whole pancreatic tissue, SLC39A14 (coding ZIP14) is the only other zinc transporter expressed abundantly in human ß cells besides well-known zinc transporter SLC30A8 (coding ZnT8). In the present work, using pancreatic ß cell-specific knockout of Slc39a14 (ß-Zip14 KO), we investigated the role of SLC39A14/ZIP14-mediated intracellular zinc trafficking in glucose-stimulated insulin secretion and subsequent metabolic responses. Glucose-stimulated insulin secretion, zinc concentrations, and cellular localization of ZIP14 were assessed using in vivo, ex vivo, and in vitro assays using ß-Zip14 KO, isolated islets, and murine cell line MIN6. Metabolic evaluations were done on both chow- and HFD-fed mice using time-domain nuclear magnetic resonance and a comprehensive laboratory animal monitoring system. ZIP14 localizes on the endoplasmic reticulum regulating intracellular zinc trafficking in ß cells and serves as a negative regulator of glucose-stimulated insulin secretion. Deletion of Zip14 resulted in greater glucose-stimulated insulin secretion, increased energy expenditure, and shifted energy metabolism toward fatty acid utilization. HFD caused ß-Zip14 KO mice to develop greater islet hyperplasia, compensatory hyperinsulinemia, and mild insulin resistance and hyperglycemia. This study provided new insights into the contribution of metal transporter ZIP14-mediated intracellular zinc trafficking in glucose-stimulated insulin secretion and subsequent metabolic responses.NEW & NOTEWORTHY Metal transporter SLC39A14/ZIP14 is downregulated in pancreatic islets of patients with T2D and mouse models of HFD- or db/db-induced obesity. However, the function of ZIP14-mediated intracellular zinc trafficking in ß cells is unknown. Our analyses revealed that SLC39A14 is the only Zn transporter expressed abundantly in human ß cells besides SLC30A8. Within the ß cells, ZIP14 is localized on the endoplasmic reticulum and serves as a negative regulator of insulin secretion, providing a potential therapeutic target for T2D.


Asunto(s)
Proteínas de Transporte de Catión , Diabetes Mellitus Tipo 2 , Hiperinsulinismo , Células Secretoras de Insulina , Humanos , Ratones , Animales , Células Secretoras de Insulina/metabolismo , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Proteínas de Transporte de Catión/genética , Proteínas de Transporte de Catión/metabolismo , Glucosa/metabolismo , Insulina/metabolismo , Hiperinsulinismo/genética , Hiperinsulinismo/metabolismo , Obesidad/genética , Obesidad/metabolismo , Zinc/metabolismo , Ratones Noqueados
9.
Plant Cell Physiol ; 2024 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-38545690

RESUMEN

The miR390-derived TAS3 trans-acting short-interfering RNAs (tasiRNAs) module represents a conserved RNA silencing pathway in the plant kingdom; however, its characterization in the bryophyte Marchantia polymorpha is limited. This study elucidated that MpDCL4 processes MpTAS3 double-stranded RNA (dsRNA) to generate tasiRNAs, primarily from the 5'- and 3'-ends of dsRNA. Notably, we discovered a novel tasiRNA, tasi78A, can negatively regulate a cytochrome P450 gene, MpCYP78A101. Additionally, tasi78A was abundant in MpAGO1, and transient expression assays underscored the role of tasi78A in repressing MpCYP78A101. A microRNA, miR11700, also regulates MpCYP78A101 expression. This coordinate regulation suggests a role in modulating auxin signaling at apical notches of gemma, influencing the growth and sexual organ development of M. polymorpha and emphasizing the significance of RNA silencing in MpCYP78A101 regulation. However, phylogenetic analysis identified another paralog of the CYP78 family, Mp1g14150, which may have a redundant role with MpCYP78A101, explaining the absence of noticeable morphological changes in loss-of-function plants. Taken together, our findings provide new insights into the combined regulatory roles of miR390/MpTAS3/miR11700 in controlling MpCYP78A101 and expand our knowledge about the biogenesis and regulation of tasiRNAs in M. polymorpha.

10.
Lancet ; 402(10405): 851-858, 2023 09 09.
Artículo en Inglés | MEDLINE | ID: mdl-37597523

RESUMEN

BACKGROUND: Levonorgestrel, a standard drug for emergency contraception (EC), is not effective if administered post-ovulation. A cyclo-oxygenase inhibitor could contribute synergistic effects. We investigated whether a single 40 mg oral dose of piroxicam as co-treatment with levonorgestrel improved emergency contraceptive efficacy. METHODS: This was a randomised double-blind placebo-controlled trial carried out in a major community sexual and reproductive health service in Hong Kong. Women who required levonorgestrel EC within 72 h of unprotected sexual intercourse were recruited and block-randomised in a 1:1 ratio to receive a single supervised dose of levonorgestrel 1·5 mg plus either piroxicam 40 mg or placebo orally. Group assignment was concealed in opaque envelopes and masked to the women, clinicians, and investigators. At follow-up 1-2 weeks after the next expected period, the pregnancy status was noted by history or pregnancy test. The primary efficacy outcome was the proportion of pregnancies prevented out of those expected based on an established model. All women randomised to receive the study drug and who completed the follow-up were analysed. The trial was registered with ClinicalTrials.gov, NCT03614494. FINDINGS: 860 women (430 in each group) were recruited between Aug 20, 2018, and Aug 30, 2022. One (0·2%) of 418 efficacy-eligible women in the piroxicam group were pregnant, compared with seven (1·7%) of 418 in the placebo group (odds ratio 0·20 [95% CI 0·02-0·91]; p=0·036). Levonorgestrel plus piroxicam prevented 94·7% of expected pregnancies compared with 63·4% for levonorgestrel plus placebo. We noted no significant difference between the two groups in the proportion of women with advancement or delay of their next period, or in the adverse event profile. INTERPRETATION: Oral piroxicam 40 mg co-administered with levonorgestrel improved efficacy of EC in our study. Piroxicam co-administration could be considered clinically where levonorgestrel EC is the option of choice. FUNDING: None.


Asunto(s)
Anticoncepción Postcoital , Anticonceptivos Poscoito , Femenino , Embarazo , Humanos , Piroxicam , Levonorgestrel , Inhibidores de la Ciclooxigenasa
11.
Small ; 20(14): e2307487, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37985946

RESUMEN

By utilizing bicontinuous and nanoporous ordered nanonetworks, such as double gyroid (DG) and double diamond (DD), metamaterials with exceptional optical and mechanical properties can be fabricated through the templating synthesis of functional materials. However, the volume fraction range of DG in block copolymers is significantly narrow, making it unable to vary its porosity and surface-to-volume ratio. Here, the theoretically limited structural volume of the DG phase in coil-coil copolymers is overcome by enlarging the conformational asymmetry through the association of mesogens, providing fast access to achieving flexible structured materials of ultra-high porosities. The new materials design, dual-extractable nanocomposite, is created by incorporating a photodegradable block with a solvent-extractable mesogen (m) into an accepting block, resulting in a new hollow gyroid (HG) with the largely increased surface-to-volume ratio and porosity of 77 vol%. The lightweight HG exhibits a low refractive index of 1.11 and a very high specific reduced modulus, almost two times that of the typical negative gyroid (porosity≈53%) and three times that of the positive gyroid (porosity≈24%). This novel concept can significantly extend the DG phase window of block copolymers and the corresponding surface-to-volume ratio, being applicable for nanotemplate-synthesized nanomaterials with a great gain of mechanical, catalytic, and optoelectronic properties.

12.
Nat Methods ; 18(6): 678-687, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-34059829

RESUMEN

We demonstrate residual channel attention networks (RCAN) for the restoration and enhancement of volumetric time-lapse (four-dimensional) fluorescence microscopy data. First we modify RCAN to handle image volumes, showing that our network enables denoising competitive with three other state-of-the-art neural networks. We use RCAN to restore noisy four-dimensional super-resolution data, enabling image capture of over tens of thousands of images (thousands of volumes) without apparent photobleaching. Second, using simulations we show that RCAN enables resolution enhancement equivalent to, or better than, other networks. Third, we exploit RCAN for denoising and resolution improvement in confocal microscopy, enabling ~2.5-fold lateral resolution enhancement using stimulated emission depletion microscopy ground truth. Fourth, we develop methods to improve spatial resolution in structured illumination microscopy using expansion microscopy data as ground truth, achieving improvements of ~1.9-fold laterally and ~3.6-fold axially. Finally, we characterize the limits of denoising and resolution enhancement, suggesting practical benchmarks for evaluation and further enhancement of network performance.


Asunto(s)
Microscopía Fluorescente/métodos , Algoritmos , Aprendizaje Profundo , Procesamiento de Imagen Asistido por Computador
13.
Hepatology ; 78(4): 1182-1199, 2023 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-37013405

RESUMEN

BACKGROUND AND AIMS: Overnutrition-induced activation of mammalian target of rapamycin (mTOR) dysregulates intracellular lipid metabolism and contributes to hepatic lipid deposition. Apolipoprotein J (ApoJ) is a molecular chaperone and participates in pathogen-induced and nutrient-induced lipid accumulation. This study investigates the mechanism of ApoJ-regulated ubiquitin-proteasomal degradation of mTOR, and a proof-of-concept ApoJ antagonist peptide is proposed to relieve hepatic steatosis. APPROACH AND RESULTS: By using omics approaches, upregulation of ApoJ was found in high-fat medium-fed hepatocytes and livers of patients with NAFLD. Hepatic ApoJ level associated with the levels of mTOR and protein markers of autophagy and correlated positively with lipid contents in the liver of mice. Functionally, nonsecreted intracellular ApoJ bound to mTOR kinase domain and prevented mTOR ubiquitination by interfering FBW7 ubiquitin ligase interaction through its R324 residue. In vitro and in vivo gain-of-function or loss-of-function analysis further demonstrated that targeting ApoJ promotes proteasomal degradation of mTOR, restores lipophagy and lysosomal activity, thus prevents hepatic lipid deposition. Moreover, an antagonist peptide with a dissociation constant (Kd) of 2.54 µM interacted with stress-induced ApoJ and improved hepatic pathology, serum lipid and glucose homeostasis, and insulin sensitivity in mice with NAFLD or type II diabetes mellitus. CONCLUSIONS: ApoJ antagonist peptide might be a potential therapeutic against lipid-associated metabolic disorders through restoring mTOR and FBW7 interaction and facilitating ubiquitin-proteasomal degradation of mTOR.


Asunto(s)
Diabetes Mellitus Tipo 2 , Enfermedad del Hígado Graso no Alcohólico , Humanos , Ratones , Animales , Clusterina/metabolismo , Enfermedad del Hígado Graso no Alcohólico/patología , Sirolimus , Hígado/patología , Serina-Treonina Quinasas TOR/metabolismo , Metabolismo de los Lípidos/fisiología , Ubiquitinas/metabolismo , Lípidos , Ratones Endogámicos C57BL , Mamíferos/metabolismo
14.
Dev Growth Differ ; 66(1): 21-34, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38239149

RESUMEN

Inherited leukodystrophies are genetic disorders characterized by abnormal white matter in the central nervous system. Although individually rare, there are more than 400 distinct types of leukodystrophies with a cumulative incidence of 1 in 4500 live births. The pathophysiology of most leukodystrophies is poorly understood, there are treatments for only a few, and there is significant morbidity and mortality, suggesting a critical need for improvements in this field. A variety of animal, cell, and induced pluripotent stem cell-derived models have been developed for leukodystrophies, but with significant limitations in all models. Many leukodystrophies lack animal models, and extant models often show no or mixed recapitulation of key phenotypes. Zebrafish (Danio rerio) have become increasingly used as disease models for studying leukodystrophies due to their early onset of disease phenotypes and conservation of molecular and neurobiological mechanisms. Here, we focus on reviewing new zebrafish disease models for leukodystrophy or models with recent progress. This includes discussion of leukodystrophy with vanishing white matter disease, X-linked adrenoleukodystrophy, Zellweger spectrum disorders and peroxisomal disorders, PSAP deficiency, metachromatic leukodystrophy, Krabbe disease, hypomyelinating leukodystrophy-8/4H leukodystrophy, Aicardi-Goutières syndrome, RNASET2-deficient cystic leukoencephalopathy, hereditary diffuse leukoencephalopathy with spheroids-1 (CSF1R-related leukoencephalopathy), and ultra-rare leukodystrophies. Zebrafish models offer important potentials for the leukodystrophy field, including testing of new variants in known genes; establishing causation of newly discovered genes; and early lead compound identification for therapies. There are also unrealized opportunities to use humanized zebrafish models which have been sparsely explored.


Asunto(s)
Adrenoleucodistrofia , Leucodistrofia de Células Globoides , Leucodistrofia Metacromática , Leucoencefalopatías , Animales , Pez Cebra/genética , Leucodistrofia Metacromática/genética , Leucodistrofia Metacromática/terapia , Leucodistrofia de Células Globoides/genética , Leucodistrofia de Células Globoides/terapia , Adrenoleucodistrofia/genética , Leucoencefalopatías/terapia
15.
Opt Lett ; 49(2): 258-261, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-38194542

RESUMEN

Modern microwave switches require high switching speeds to rapidly route data over multiple radio channels while minimizing the routing delay. This Letter proposes a novel, to the best of our knowledge, microwave frequency switching system using phase-locked Period-one (P1) dynamics of semiconductor lasers. When a semiconductor laser is optically injected by microwave-modulated optical signals, which carry two-tone input microwaves at 29 and 37 GHz, with proper injection power controlled by dual-voltage control signals, P1 dynamics are excited in the semiconductor laser and subsequently phase-locked by one of the input microwave tones. We have observed positive and negative switching delays in the switching process. For instance, a positive delay is observed when the system requires additional optical power to transition from a phase-locked state at 29 GHz to an unlocked state. Conversely, a negative delay occurs when the unlocked P1 dynamics approach but do not reach a 37-GHz frequency and then rapidly lock to the tone, thereby surpassing the speed of the control signals. These dual delays are instrumental in enhancing the switching speed of our system, enabling it to surpass the voltage switching time of the control signals by a factor of 3.6. In addition, by leveraging these dual delays, the duration of the microwave tones can be further extended in the switching process.

16.
BMC Cancer ; 24(1): 121, 2024 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-38267903

RESUMEN

BACKGROUND: Programmed death-1 (PD-1) and programmed death-ligand 1 (PD-L1) are the two most common immune checkpoints targeted in triple-negative breast cancer (BC). Refining patient selection for immunotherapy is non-trivial and finding an appropriate digital pathology framework for spatial analysis of theranostic biomarkers for PD-1/PD-L1 inhibitors remains an unmet clinical need. METHODS: We describe a novel computer-assisted tool for three-dimensional (3D) imaging of PD-L1 expression in immunofluorescence-stained and optically cleared BC specimens (n = 20). The proposed 3D framework appeared to be feasible and showed a high overall agreement with traditional, clinical-grade two-dimensional (2D) staining techniques. Additionally, the results obtained for automated immune cell detection and analysis of PD-L1 expression were satisfactory. RESULTS: The spatial distribution of PD-L1 expression was heterogeneous across various BC tissue layers in the 3D space. Notably, there were six cases (30%) wherein PD-L1 expression levels along different layers crossed the 1% threshold for admitting patients to PD-1/PD-L1 inhibitors. The average PD-L1 expression in 3D space was different from that of traditional immunohistochemistry (IHC) in eight cases (40%). Pending further standardization and optimization, we expect that our technology will become a valuable addition for assessing PD-L1 expression in patients with BC. CONCLUSION: Via a single round of immunofluorescence imaging, our approach may provide a considerable improvement in patient stratification for cancer immunotherapy as compared with standard techniques.


Asunto(s)
Antígeno B7-H1 , Neoplasias de la Mama , Humanos , Femenino , Imagenología Tridimensional , Inhibidores de Puntos de Control Inmunológico , Ligandos , Receptor de Muerte Celular Programada 1 , Colorantes , Computadores
17.
Acta Psychiatr Scand ; 150(1): 5-21, 2024 07.
Artículo en Inglés | MEDLINE | ID: mdl-38616056

RESUMEN

INTRODUCTION: Despite its high lifetime prevalence rate and the elevated disability caused by posttraumatic stress disorder (PTSD), treatments exhibit modest efficacy. In consideration of the abnormal connectivity between the dorsolateral prefrontal cortex (DLPFC) and amygdala in PTSD, several randomized controlled trials (RCTs) addressing the efficacy of different noninvasive brain stimulation (NIBS) modalities for PTSD management have been undertaken. However, previous RCTs have reported inconsistent results. The current network meta-analysis (NMA) aimed to compare the efficacy and acceptability of various NIBS protocols in PTSD management. METHODS: We systematically searched ClinicalKey, Cochrane Central Register of Controlled Trials, Embase, ProQuest, PubMed, ScienceDirect, Web of Science, and ClinicalTrials.gov to identify relevant RCTs. The targeted RCTs was those comparing the efficacy of NIBS interventions, such as transcranial direct current stimulation (tDCS), repetitive transcranial magnetic stimulation (rTMS), and transcutaneous cervical vagal nerve stimulation, in patients with PTSD. The NMA was conducted using a frequentist model. The primary outcomes were changes in the overall severity of PTSD and acceptability (to be specific, rates of dropouts for any reason). RESULTS: We identified 14 RCTs that enrolled 686 participants. The NMA demonstrated that among the investigated NIBS types, high-frequency rTMS over bilateral DLPFCs was associated with the greatest reduction in overall PTSD severity. Further, in comparison with the sham controls, excitatory stimulation over the right DLPFC with/without excitatory stimulation over left DLPFC were associated with significant reductions in PTSD-related symptoms, including depression and anxiety symptoms, and overall PTSD severity. CONCLUSIONS: This NMA demonstrated that excitatory stimulation over the right DLPFC with or without excitatory stimulation over left DLPFC were associated with significant reductions in PTSD-related symptoms. TRIAL REGISTRATION: PROSPERO CRD42023391562.


Asunto(s)
Metaanálisis en Red , Ensayos Clínicos Controlados Aleatorios como Asunto , Trastornos por Estrés Postraumático , Estimulación Transcraneal de Corriente Directa , Estimulación Magnética Transcraneal , Humanos , Aceptación de la Atención de Salud , Trastornos por Estrés Postraumático/terapia , Estimulación Transcraneal de Corriente Directa/métodos , Estimulación Magnética Transcraneal/métodos , Resultado del Tratamiento , Estimulación del Nervio Vago/métodos
18.
Fish Shellfish Immunol ; 149: 109556, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38608848

RESUMEN

Japanese eel, Anguilla japonica, holds significant importance in Taiwanese aquaculture. With the intensification of eel farming, the impact of Edwardsiella tarda has become increasingly severe. Consequently, the abusive use of antibiotics has risen. Bacillus subtilis natto NTU-18, a strain of Bacillus with a high survival rate in feed processing, plays a crucial role in promoting intestinal health through competitive rejection, enhancing immune responses against bacterial pathogens, and improving intestinal health by modulating gastrointestinal microbiota to produce beneficial metabolites of mice and grass carp, Ctenopharyngodon idella. This study investigated the effects of different proportions (control, 0.25 %, 0.5 %, 1 %, and 2 %) of B. subtilis natto NTU-18 added to paste feed on the growth performance, intestinal morphology, and microbiota, expression of immune-related genes, and resistance to E. tarda in Japanese glass eel. The results indicated that the growth performance of all groups with B. subtilis natto NTU-18 added was significantly higher than that of the control group and did not impact the villi morphology. The expression of immune-related genes in the kidney, specifically HSP70 and SOD, was significantly higher from 0.5 % and above than the control; however, no significant differences were observed in CAT, POD, and HSP90. In the liver, significant differences were found in HSP70 and IgM above 0.25 % compared to the control group, with no significant differences in SOD, CAT, POD, and HSP90 among all groups. Additionally, intestinal microbiota analysis revealed that the 2 % additional group had significantly lower diversity than other groups, with Cetobacterium as the dominant species. The challenge test observed that the survival rates of the 0.5 % and 1 % groups were significantly higher. This research suggests that adding 0.5 % and 1 % of B. subtilis natto NTU-18 to the diet is beneficial for Japanese glass eel's immunity, growth performance, and disease resistance.


Asunto(s)
Anguilla , Alimentación Animal , Bacillus subtilis , Dieta , Resistencia a la Enfermedad , Enfermedades de los Peces , Microbioma Gastrointestinal , Intestinos , Probióticos , Animales , Microbioma Gastrointestinal/efectos de los fármacos , Anguilla/inmunología , Anguilla/crecimiento & desarrollo , Alimentación Animal/análisis , Resistencia a la Enfermedad/efectos de los fármacos , Enfermedades de los Peces/inmunología , Dieta/veterinaria , Probióticos/farmacología , Probióticos/administración & dosificación , Intestinos/inmunología , Infecciones por Enterobacteriaceae/inmunología , Infecciones por Enterobacteriaceae/veterinaria , Edwardsiella tarda/fisiología , Suplementos Dietéticos/análisis , Inmunidad Innata , Distribución Aleatoria
19.
J Asthma ; 61(7): 736-744, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38190281

RESUMEN

OBJECTIVE: The purpose of this study was to assess: (1) the prevalence of long COVID by asthma status, and (2) the characteristics associated with developing long COVID among adults with asthma in the United States. METHODS: Data from the 2022 National Health Interview Survey were used. The prevalence of long COVID was reported and stratified by asthma status. The multivariable logistic regression model was conducted to identify the factors associated with developing long COVID. RESULTS: In 2022, the overall prevalence of long COVID among U.S. adults was 6.9%. When stratified by asthma status, the prevalence of long COVID was 13.9% among adults with asthma, and 6.2% among adults without asthma. Among adults with asthma, certain characteristics, including age over 55 years, female sex, obesity, problems paying medical bills and a history of asthma attacks, were significantly associated with developing long COVID. CONCLUSIONS: This study revealed that the prevalence of long COVID among adults with asthma was much higher than the general adult population in the United States. The limited validity of the collected information in this study should prompt caution when interpreting our findings. Further studies on the association between asthma and long COVID could be valuable for the clinical practice.


Asunto(s)
Asma , COVID-19 , Humanos , Asma/epidemiología , Estados Unidos/epidemiología , Femenino , Masculino , COVID-19/epidemiología , Persona de Mediana Edad , Adulto , Prevalencia , Adulto Joven , Anciano , SARS-CoV-2 , Adolescente , Factores de Edad , Encuestas Epidemiológicas , Factores Sexuales , Factores de Riesgo
20.
Ann Clin Microbiol Antimicrob ; 23(1): 15, 2024 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-38350983

RESUMEN

PURPOSE: Multidrug-resistant (MDR) bacteria impose a considerable health-care burden and are associated with bronchiectasis exacerbation. This study investigated the clinical outcomes of adult patients with bronchiectasis following MDR bacterial infection. METHODS: From the Chang Gung Research Database, we identified patients with bronchiectasis and MDR bacterial infection from 2008 to 2017. The control group comprised patients with bronchiectasis who did not have MDR bacterial infection and were propensity-score matched at a 1:2 ratio. The main outcomes were in-hospital and 3-year mortality. RESULTS: In total, 554 patients with both bronchiectasis and MDR bacterial infection were identified. The types of MDR bacteria that most commonly affected the patients were MDR- Acinetobacter baumannii (38.6%) and methicillin-resistant Staphylococcus aureus (18.4%), Extended-spectrum-beta-lactamases (ESBL)- Klebsiella pneumoniae (17.8%), MDR-Pseudomonas (14.8%), and ESBL-E. coli (7.5%). Compared with the control group, the MDR group exhibited lower body mass index scores, higher rate of chronic bacterial colonization, a higher rate of previous exacerbations, and an increased use of antibiotics. Furthermore, the MDR group exhibited a higher rate of respiratory failure during hospitalization (MDR vs. control, 41.3% vs. 12.4%; p < 0.001). The MDR and control groups exhibited in-hospital mortality rates of 26.7% and 7.6%, respectively (p < 0.001); 3-year respiratory failure rates of 33.5% and 13.5%, respectively (p < 0.001); and 3-year mortality rates of 73.3% and 41.5%, respectively (p < 0.001). After adjustments were made for confounding factors, the infection with MDR and MDR bacteria species were determined to be independent risk factors affecting in-hospital and 3-year mortality. CONCLUSIONS: MDR bacteria were discovered in patients with more severe bronchiectasis and were independently associated with an increased risk of in-hospital and 3-year mortality. Given our findings, we recommend that clinicians identify patients at risk of MDR bacterial infection and follow the principle of antimicrobial stewardship to prevent the emergence of resistant bacteria among patients with bronchiectasis.


Asunto(s)
Infecciones Bacterianas , Bronquiectasia , Staphylococcus aureus Resistente a Meticilina , Insuficiencia Respiratoria , Adulto , Humanos , Escherichia coli , Antibacterianos/uso terapéutico , Antibacterianos/farmacología , Bronquiectasia/tratamiento farmacológico , Bronquiectasia/epidemiología , Infecciones Bacterianas/tratamiento farmacológico , Infecciones Bacterianas/epidemiología , Infecciones Bacterianas/microbiología , Fibrosis , Insuficiencia Respiratoria/tratamiento farmacológico , Farmacorresistencia Bacteriana Múltiple
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA