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1.
Nat Metab ; 6(9): 1712-1735, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39261628

RESUMEN

Glucose, the primary cellular energy source, is metabolized through glycolysis initiated by the rate-limiting enzyme hexokinase (HK). In energy-demanding tissues like the brain, HK1 is the dominant isoform, primarily localized on mitochondria, and is crucial for efficient glycolysis-oxidative phosphorylation coupling and optimal energy generation. This study unveils a unique mechanism regulating HK1 activity, glycolysis and the dynamics of mitochondrial coupling, mediated by the metabolic sensor enzyme O-GlcNAc transferase (OGT). OGT catalyses reversible O-GlcNAcylation, a post-translational modification influenced by glucose flux. Elevated OGT activity induces dynamic O-GlcNAcylation of the regulatory domain of HK1, subsequently promoting the assembly of the glycolytic metabolon on the outer mitochondrial membrane. This modification enhances the mitochondrial association with HK1, orchestrating glycolytic and mitochondrial ATP production. Mutation in HK1's O-GlcNAcylation site reduces ATP generation in multiple cell types, specifically affecting metabolic efficiency in neurons. This study reveals a previously unappreciated pathway that links neuronal metabolism and mitochondrial function through OGT and the formation of the glycolytic metabolon, providing potential strategies for tackling metabolic and neurological disorders.


Asunto(s)
Glucólisis , Hexoquinasa , Mitocondrias , N-Acetilglucosaminiltransferasas , Mitocondrias/metabolismo , Hexoquinasa/metabolismo , Humanos , N-Acetilglucosaminiltransferasas/metabolismo , N-Acetilglucosaminiltransferasas/genética , Animales , Neuronas/metabolismo , Adenosina Trifosfato/metabolismo , Glucosa/metabolismo , Procesamiento Proteico-Postraduccional , Ratones , Fosforilación Oxidativa
2.
Commun Biol ; 7(1): 1179, 2024 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-39300128

RESUMEN

Proteins can be targeted for degradation by engineering biomolecules that direct them to the eukaryotic ubiquitination machinery. For instance, the fusion of an E3 ubiquitin ligase to a suitable target binding domain creates a 'biological Proteolysis-Targeting Chimera' (bioPROTAC). Here we employ an analogous approach where the target protein is recruited directly to a human E2 ubiquitin-conjugating enzyme via an attached target binding domain. Through rational design and screening we develop E2 bioPROTACs that induce the degradation of the human intracellular proteins SHP2 and KRAS. Using global proteomics, we characterise the target-specific and wider effects of E2 vs. VHL-based fusions. Taking SHP2 as a model target, we also employ a route to bioPROTAC discovery based on protein display libraries, yielding a degrader with comparatively weak affinity capable of suppressing SHP2-mediated signalling.


Asunto(s)
Proteína Tirosina Fosfatasa no Receptora Tipo 11 , Proteolisis , Enzimas Ubiquitina-Conjugadoras , Humanos , Enzimas Ubiquitina-Conjugadoras/metabolismo , Enzimas Ubiquitina-Conjugadoras/genética , Proteína Tirosina Fosfatasa no Receptora Tipo 11/metabolismo , Proteína Tirosina Fosfatasa no Receptora Tipo 11/genética , Ubiquitinación , Proteínas Proto-Oncogénicas p21(ras)/metabolismo , Proteínas Proto-Oncogénicas p21(ras)/genética , Proteínas Recombinantes de Fusión/metabolismo , Proteínas Recombinantes de Fusión/genética , Células HEK293 , Proteómica/métodos , Unión Proteica
3.
bioRxiv ; 2024 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-39091793

RESUMEN

In drug development, assessing the toxicity of candidate compounds is crucial for successfully transitioning from preclinical research to early-stage clinical trials. Drug safety is typically assessed using animal models with a manual histopathological examination of tissue sections to characterize the dose-response relationship of the compound - a time-intensive process prone to inter-observer variability and predominantly involving tedious review of cases without abnormalities. Artificial intelligence (AI) methods in pathology hold promise to accelerate this assessment and enhance reproducibility and objectivity. Here, we introduce TRACE, a model designed for toxicologic liver histopathology assessment capable of tackling a range of diagnostic tasks across multiple scales, including situations where labeled data is limited. TRACE was trained on 15 million histopathology images extracted from 46,734 digitized tissue sections from 157 preclinical studies conducted on Rattus norvegicus. We show that TRACE can perform various downstream toxicology tasks spanning histopathological response assessment, lesion severity scoring, morphological retrieval, and automatic dose-response characterization. In an independent reader study, TRACE was evaluated alongside ten board-certified veterinary pathologists and achieved higher concordance with the consensus opinion than the average of the pathologists. Our study represents a substantial leap over existing computational models in toxicology by offering the first framework for accelerating and automating toxicological pathology assessment, promoting significant progress with faster, more consistent, and reliable diagnostic processes.

4.
Lab Chip ; 24(18): 4357-4370, 2024 09 10.
Artículo en Inglés | MEDLINE | ID: mdl-39148312

RESUMEN

The ability to cost-effectively produce large surface area microfluidic devices would bring many small-scale technologies such as microfluidic artificial lungs (µALs) from the realm of research to clinical and commercial applications. However, efforts to scale up these devices, such as by stacking multiple flat µALs have been labor intensive and resulted in bulky devices. Here, we report an automated manufacturing system, and a series of cylindrical multi-layer lungs manufactured with the system and tested for fluidic fidelity and function. A roll-to-roll (R2R) system to engrave multiple-layer devices was assembled. Unlike typical applications of R2R, the rolling process is synchronized to achieve consistent radial positioning. This allows the fluidics in the final device to be accessed without being unwrapped. To demonstrate the capabilities of the R2R manufacturing system, this method was used to manufacture multi-layer µALs. Gas and blood are engraved in alternating layers and routed orthogonally to each other. The proximity of gas and blood separated by gas permeable PDMS permits CO2 and O2 exchange via diffusion. After manufacturing, they were evaluated using water for pressure drop and CO2 gas exchange. The best performing device was tested with fresh whole bovine blood for O2 exchange. Three µALs were successfully manufactured and passed leak testing. The top performing device had 15 alternating blood and gas layers. It oxygenated blood from 70% saturation to 95% saturation at a blood flow of 3 mL min-1 and blood side pressure drop of 234 mmHg. This new roll-to-roll manufacturing system is suitable for the automated construction of multi-layer microfluidic devices that are difficult to manufacture by conventional means. With some upgrades and improvements, this technology should allow for the automatic creation of large surface area microfluidic devices that can be employed for various applications including large-scale membrane gas exchange such as clinical-scale microfluidic artificial lungs.


Asunto(s)
Órganos Artificiales , Dimetilpolisiloxanos , Dispositivos Laboratorio en un Chip , Pulmón , Dimetilpolisiloxanos/química , Animales , Diseño de Equipo , Técnicas Analíticas Microfluídicas/instrumentación , Propiedades de Superficie
5.
Dev Cell ; 59(16): 2143-2157.e9, 2024 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-38843836

RESUMEN

Neuronal activity is an energy-intensive process that is largely sustained by instantaneous fuel utilization and ATP synthesis. However, how neurons couple ATP synthesis rate to fuel availability is largely unknown. Here, we demonstrate that the metabolic sensor enzyme O-linked N-acetyl glucosamine (O-GlcNAc) transferase regulates neuronal activity-driven mitochondrial bioenergetics in hippocampal and cortical neurons. We show that neuronal activity upregulates O-GlcNAcylation in mitochondria. Mitochondrial O-GlcNAcylation is promoted by activity-driven glucose consumption, which allows neurons to compensate for high energy expenditure based on fuel availability. To determine the proteins that are responsible for these adjustments, we mapped the mitochondrial O-GlcNAcome of neurons. Finally, we determine that neurons fail to meet activity-driven metabolic demand when O-GlcNAcylation dynamics are prevented. Our findings suggest that O-GlcNAcylation provides a fuel-dependent feedforward control mechanism in neurons to optimize mitochondrial performance based on neuronal activity. This mechanism thereby couples neuronal metabolism to mitochondrial bioenergetics and plays a key role in sustaining energy homeostasis.


Asunto(s)
Acetilglucosamina , Metabolismo Energético , Mitocondrias , N-Acetilglucosaminiltransferasas , Neuronas , Neuronas/metabolismo , Animales , Mitocondrias/metabolismo , N-Acetilglucosaminiltransferasas/metabolismo , N-Acetilglucosaminiltransferasas/genética , Acetilglucosamina/metabolismo , Ratones , Hipocampo/metabolismo , Hipocampo/citología , Glucosa/metabolismo , Ratones Endogámicos C57BL , Plasticidad Neuronal/fisiología
6.
Aging Dis ; 15(5): 2168-2190, 2024 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-38916729

RESUMEN

Alzheimer's disease (AD) is an age-dependent neurodegenerative disease characterized by extracellular Amyloid Aß peptide (Aß) deposition and intracellular Tau protein aggregation. Glia, especially microglia and astrocytes are core participants during the progression of AD and these cells are the mediators of Aß clearance and degradation. The microbiota-gut-brain axis (MGBA) is a complex interactive network between the gut and brain involved in neurodegeneration. MGBA affects the function of glia in the central nervous system (CNS), and microbial metabolites regulate the communication between astrocytes and microglia; however, whether such communication is part of AD pathophysiology remains unknown. One of the potential links in bilateral gut-brain communication is tryptophan (Trp) metabolism. The microbiota-originated Trp and its metabolites enter the CNS to control microglial activation, and the activated microglia subsequently affect astrocyte functions. The present review highlights the role of MGBA in AD pathology, especially the roles of Trp per se and its metabolism as a part of the gut microbiota and brain communications. We (i) discuss the roles of Trp derivatives in microglia-astrocyte crosstalk from a bioinformatics perspective, (ii) describe the role of glia polarization in the microglia-astrocyte crosstalk and AD pathology, and (iii) summarize the potential of Trp metabolism as a therapeutic target. Finally, we review the role of Trp in AD from the perspective of the gut-brain axis and microglia, as well as astrocyte crosstalk, to inspire the discovery of novel AD therapeutics.


Asunto(s)
Enfermedad de Alzheimer , Astrocitos , Eje Cerebro-Intestino , Microbioma Gastrointestinal , Microglía , Triptófano , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/patología , Humanos , Astrocitos/metabolismo , Microglía/metabolismo , Triptófano/metabolismo , Eje Cerebro-Intestino/fisiología , Microbioma Gastrointestinal/fisiología , Encéfalo/metabolismo , Encéfalo/patología , Animales
7.
N Am Spine Soc J ; 18: 100325, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38812953

RESUMEN

Background: In anterior lumbar interbody fusion (ALIF), the use of integrated screws is attractive to surgeons because of the ease of implantation and no additional profile. However, the number and length of screws necessary for safe and stable implantation in various bone densities is not yet fully understood. The current study aims to determine how important both length and number of screws are for stability of ALIFs. Methods: Three bone models with densities of 10, 15, and 20 pounds per cubic foot (PCF) were chosen as surrogates. These were instrumented using the Z-Link lumbar interbody system with either 2, 3, or 4 integrated 4.5 × 20 mm screws or 4.5 × 25 mm screws (Zavation, LLC, Flowood, MS). The bone surrogates were tested with loading conditions resulting in spine extension to measure construct stiffness and peak force. Results: The failure load of the construct was influenced by the length of screws (p=.01) and density of the bone surrogate (p<.01). There was no difference in failure load between using 2 screws and 3 screws (p=.32) or when using four 20 mm screws versus three 25 mm screws (p=.295). Conclusion: In our study, both bone density and length of screws significantly affected the construct's load to failure. In certain cases where a greater number of screws are unable to be implanted, the same stability can potentially be conferred with use of longer screws. Future clinical studies should be performed to test these biomechanical results.

8.
JBJS Rev ; 12(5)2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38709859

RESUMEN

¼ Coccydynia is a painful condition affecting many patients at the terminal caudal end of the spine.¼ An understanding of coccyx anatomy and variations of morphology is necessary for proper diagnosis. A multifactorial etiology for pain may be responsible for this clinical entity.¼ Several treatment options exist. Successful outcomes for patients depend on individual patient characteristics and the etiology of pain.


Asunto(s)
Cóccix , Humanos , Dolor de la Región Lumbar/terapia , Dolor de la Región Lumbar/etiología , Dolor de la Región Lumbar/diagnóstico
9.
Cell ; 187(10): 2502-2520.e17, 2024 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-38729110

RESUMEN

Human tissue, which is inherently three-dimensional (3D), is traditionally examined through standard-of-care histopathology as limited two-dimensional (2D) cross-sections that can insufficiently represent the tissue due to sampling bias. To holistically characterize histomorphology, 3D imaging modalities have been developed, but clinical translation is hampered by complex manual evaluation and lack of computational platforms to distill clinical insights from large, high-resolution datasets. We present TriPath, a deep-learning platform for processing tissue volumes and efficiently predicting clinical outcomes based on 3D morphological features. Recurrence risk-stratification models were trained on prostate cancer specimens imaged with open-top light-sheet microscopy or microcomputed tomography. By comprehensively capturing 3D morphologies, 3D volume-based prognostication achieves superior performance to traditional 2D slice-based approaches, including clinical/histopathological baselines from six certified genitourinary pathologists. Incorporating greater tissue volume improves prognostic performance and mitigates risk prediction variability from sampling bias, further emphasizing the value of capturing larger extents of heterogeneous morphology.


Asunto(s)
Imagenología Tridimensional , Neoplasias de la Próstata , Aprendizaje Automático Supervisado , Humanos , Masculino , Aprendizaje Profundo , Imagenología Tridimensional/métodos , Pronóstico , Neoplasias de la Próstata/patología , Neoplasias de la Próstata/diagnóstico por imagen , Microtomografía por Rayos X/métodos
10.
G3 (Bethesda) ; 14(6)2024 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-38620009

RESUMEN

Here, we describe a high-quality genome assembly and annotation of the convergent lady beetle, Hippodamia convergens (Coleoptera: Coccinellidae). The highest quality unmasked genome comprises 619 megabases (Mb) of chromosomal DNA, organized into 899 contigs, with a contig N50 score of 89 Mbps. The genome was assessed to be 96% complete (BUSCO). Reconstruction of a whole-genome phylogeny resolved H. convergens as sister to the Harlequin lady beetle, Harmonia axyridis, and nested within a clade of several known agricultural pests.


Asunto(s)
Escarabajos , Genoma de los Insectos , Anotación de Secuencia Molecular , Filogenia , Animales , Escarabajos/genética , Genómica/métodos
11.
ACS Chem Biol ; 19(4): 962-972, 2024 04 19.
Artículo en Inglés | MEDLINE | ID: mdl-38509779

RESUMEN

Inhibition of the NLRP3 inflammasome is a promising strategy for the development of new treatments for inflammatory diseases. MCC950 is a potent and selective small-molecule inhibitor of the NLRP3 pathway and has been validated in numerous species and disease models. Although the capacity of MCC950 to block NLRP3 signaling is well-established, it is still critical to identify the mechanism of action and molecular targets of MCC950 to inform and derisk drug development. Quantitative proteomics performed in disease-relevant systems provides a powerful method to study both direct and indirect pharmacological responses to small molecules to elucidate the mechanism of action and confirm target engagement. A comprehensive target deconvolution campaign requires the use of complementary chemical biology techniques. Here we applied two orthogonal chemical biology techniques: compressed Cellular Thermal Shift Assay (CETSA) and photoaffinity labeling chemoproteomics, performed under biologically relevant conditions with LPS-primed THP-1 cells, thereby deconvoluting, for the first time, the molecular targets of MCC950 using chemical biology techniques. In-cell chemoproteomics with inlysate CETSA confirmed the suspected mechanism as the disruption of inflammasome formation via NLRP3. Further cCETSA (c indicates compressed) in live cells mapped the stabilization of NLRP3 inflammasome pathway proteins, highlighting modulation of the targeted pathway. This is the first evidence of direct MCC950 engagement with endogenous NLRP3 in a human macrophage cellular system using discovery proteomics chemical biology techniques, providing critical information for inflammasome studies.


Asunto(s)
Inflamasomas , Proteína con Dominio Pirina 3 de la Familia NLR , Animales , Humanos , Línea Celular , Modelos Animales de Enfermedad , Furanos/farmacología , Inflamasomas/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Proteómica , Sulfonamidas/farmacología , Sulfonas/farmacología
12.
Nat Med ; 30(3): 863-874, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38504017

RESUMEN

The accelerated adoption of digital pathology and advances in deep learning have enabled the development of robust models for various pathology tasks across a diverse array of diseases and patient cohorts. However, model training is often difficult due to label scarcity in the medical domain, and a model's usage is limited by the specific task and disease for which it is trained. Additionally, most models in histopathology leverage only image data, a stark contrast to how humans teach each other and reason about histopathologic entities. We introduce CONtrastive learning from Captions for Histopathology (CONCH), a visual-language foundation model developed using diverse sources of histopathology images, biomedical text and, notably, over 1.17 million image-caption pairs through task-agnostic pretraining. Evaluated on a suite of 14 diverse benchmarks, CONCH can be transferred to a wide range of downstream tasks involving histopathology images and/or text, achieving state-of-the-art performance on histology image classification, segmentation, captioning, and text-to-image and image-to-text retrieval. CONCH represents a substantial leap over concurrent visual-language pretrained systems for histopathology, with the potential to directly facilitate a wide array of machine learning-based workflows requiring minimal or no further supervised fine-tuning.


Asunto(s)
Lenguaje , Aprendizaje Automático , Humanos , Flujo de Trabajo
13.
Nat Med ; 30(3): 850-862, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38504018

RESUMEN

Quantitative evaluation of tissue images is crucial for computational pathology (CPath) tasks, requiring the objective characterization of histopathological entities from whole-slide images (WSIs). The high resolution of WSIs and the variability of morphological features present significant challenges, complicating the large-scale annotation of data for high-performance applications. To address this challenge, current efforts have proposed the use of pretrained image encoders through transfer learning from natural image datasets or self-supervised learning on publicly available histopathology datasets, but have not been extensively developed and evaluated across diverse tissue types at scale. We introduce UNI, a general-purpose self-supervised model for pathology, pretrained using more than 100 million images from over 100,000 diagnostic H&E-stained WSIs (>77 TB of data) across 20 major tissue types. The model was evaluated on 34 representative CPath tasks of varying diagnostic difficulty. In addition to outperforming previous state-of-the-art models, we demonstrate new modeling capabilities in CPath such as resolution-agnostic tissue classification, slide classification using few-shot class prototypes, and disease subtyping generalization in classifying up to 108 cancer types in the OncoTree classification system. UNI advances unsupervised representation learning at scale in CPath in terms of both pretraining data and downstream evaluation, enabling data-efficient artificial intelligence models that can generalize and transfer to a wide range of diagnostically challenging tasks and clinical workflows in anatomic pathology.


Asunto(s)
Inteligencia Artificial , Flujo de Trabajo
14.
Artículo en Inglés | MEDLINE | ID: mdl-38553309

RESUMEN

OBJECTIVE: Central odontogenic fibromas (COF) are rare, benign tumors derived from dental mesenchymal tissue that may occur in the maxilla or mandible. This report describes primary and recurrent COF in the mandible of a patient with nevoid basal cell carcinoma syndrome (NBCCS). STUDY DESIGN: A 36-year-old African American male presented with a COF and its recurrence 17 months later. Tissue pieces were obtained from both occurrences with IRB-approved signed consent. Collected tissue pieces were dissected; one portion was formalin-fixed and paraffin-embedded, and the other was cultured for the isolation of cell populations from the primary (COdF-1) and recurrent (COdF-1a) tumors. Quantification real-time polymerase chain reaction (qRT-PCR), immunohistochemistry, and DNA sequencing were used for gene and protein analysis of the primary tumor and cell populations. RESULTS: Histopathologic analysis of the tumor showed sparse odontogenic epithelial cords in fibrous connective tissue, and qRT-PCR analysis of tumor and cell populations (COdF-1 and COdF-1a) detected VIM, CK14, CD34, CD99 and ALPL mRNA expression. Protein expression was confirmed by immunohistochemistry. CD34 expression in primary tissues was higher than in tumor cells due to tumor vascularization. DNA sequencing indicated the patient had PTCH1 mutations. CONCLUSIONS: Histopathology, mRNA, and protein expression indicate the rare occurrence of COF in a patient with mutated PTCH1 gene and NBCCS.


Asunto(s)
Síndrome del Nevo Basocelular , Fibroma , Recurrencia Local de Neoplasia , Tumores Odontogénicos , Humanos , Masculino , Síndrome del Nevo Basocelular/genética , Síndrome del Nevo Basocelular/patología , Tumores Odontogénicos/patología , Tumores Odontogénicos/genética , Tumores Odontogénicos/cirugía , Adulto , Recurrencia Local de Neoplasia/patología , Fibroma/patología , Fibroma/genética , Fibroma/cirugía , Inmunohistoquímica , Neoplasias Mandibulares/patología , Neoplasias Mandibulares/genética , Neoplasias Mandibulares/cirugía , Reacción en Cadena en Tiempo Real de la Polimerasa , Técnicas In Vitro
15.
Lab Chip ; 24(4): 955-965, 2024 02 13.
Artículo en Inglés | MEDLINE | ID: mdl-38275173

RESUMEN

Microfluidic artificial lungs (µALs) are a new class of membrane oxygenators. Compared to traditional hollow-fiber oxygenators, µALs closely mimic the alveolar microenvironment due to their size-scale and promise improved gas exchange efficiency, hemocompatibility, biomimetic blood flow networks, and physiologically relevant blood vessel pressures and shear stresses. Clinical translation of µALs has been stalled by restrictive microfabrication techniques that limit potential artificial lung geometries, overall device size, and throughput. To address these limitations, a high-resolution Asiga MAX X27 UV digital light processing (DLP) 3D printer and custom photopolymerizable polydimethylsiloxane (PDMS) resin were used to rapidly manufacture small-scale µALs via vat photopolymerization (VPP). Devices were designed in SOLIDWORKS with 500 blood channels and 252 gas channels, where gas and blood flow channels were oriented orthogonally and separated by membranes on the top and bottom, permitting two-sided gas exchange. Successful devices were post-processed to remove uncured resin from microchannels and assembled with external tubing in preparation for gas exchange performance testing with ovine whole blood. 3D printed channel dimensions were 172 µm-tall × 320 µm-wide, with 62 µm-thick membranes and 124 µm-wide support columns. Measured outlet blood oxygen saturation (SO2) agreed with theoretical models and rated flow of the device was 1 mL min-1. Blood side pressure drop was 1.58 mmHg at rated flow. This work presents the highest density of 3D printed microchannels in a single device, one of the highest CO2 transfer efficiencies of any artificial lung to date, and a promising approach to translate µALs one step closer to the clinic.


Asunto(s)
Microfluídica , Intercambio Gaseoso Pulmonar , Ovinos , Animales , Intercambio Gaseoso Pulmonar/fisiología , Biomimética , Pulmón/fisiología , Impresión Tridimensional
16.
J Med Chem ; 67(2): 1500-1512, 2024 01 25.
Artículo en Inglés | MEDLINE | ID: mdl-38227216

RESUMEN

Casitas B-lymphoma proto-oncogene-b (Cbl-b), a member of the Cbl family of RING finger E3 ubiquitin ligases, has been demonstrated to play a central role in regulating effector T-cell function. Multiple studies using gene-targeting approaches have provided direct evidence that Cbl-b negatively regulates T, B, and NK cell activation via a ubiquitin-mediated protein modulation. Thus, inhibition of Cbl-b ligase activity can lead to immune activation and has therapeutic potential in immuno-oncology. Herein, we describe the discovery and optimization of an arylpyridone series as Cbl-b inhibitors by structure-based drug discovery to afford compound 31. This compound binds to Cbl-b with an IC50 value of 30 nM and induces IL-2 production in T-cells with an EC50 value of 230 nM. Compound 31 also shows robust intracellular target engagement demonstrated through inhibition of Cbl-b autoubiquitination, inhibition of ubiquitin transfer to ZAP70, and the cellular modulation of phosphorylation of a downstream signal within the TCR axis.


Asunto(s)
Proteínas Proto-Oncogénicas c-cbl , Ubiquitina-Proteína Ligasas , Proteínas Proto-Oncogénicas c-cbl/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Linfocitos T/metabolismo , Fosforilación , Ubiquitina/metabolismo
17.
J Hand Surg Eur Vol ; 49(3): 310-315, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37666217

RESUMEN

We assessed operatively treated closed distal radial fractures to identify independent risk factors for surgical site infection after treatment. A retrospective review was carried out of 531 operatively treated closed distal radial fractures over a 5-year period. Multiple logistic regression was performed with infection as the dependent variable, using a stepwise regression procedure to select variables to construct the final model. In total, 19 (3.6%) fractures were complicated by postoperative surgical site infection. Uncontrolled diabetes with HbA1c >7, the presence of external fixation or external Kirschner wires, and tobacco use were significant independent predictors of infection. Age and time in the operating room were also statistically significant predictors but deemed to be not clinically meaningful.Level of evidence: IV.


Asunto(s)
Fracturas del Radio , Infección de la Herida Quirúrgica , Humanos , Infección de la Herida Quirúrgica/epidemiología , Infección de la Herida Quirúrgica/etiología , Fracturas del Radio/cirugía , Fracturas del Radio/etiología , Fijación de Fractura/efectos adversos , Fijación de Fractura/métodos , Fijación Interna de Fracturas/efectos adversos , Fijación Interna de Fracturas/métodos , Estudios Retrospectivos , Hilos Ortopédicos , Factores de Riesgo , Resultado del Tratamiento
18.
J Pineal Res ; 76(1): e12925, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37986632

RESUMEN

Stroke is the leading cause of death and disability worldwide. Novel and effective therapies for ischemic stroke are urgently needed. Here, we report that melatonin receptor 1A (MT1) agonist ramelteon is a neuroprotective drug candidate as demonstrated by comprehensive experimental models of ischemic stroke, including a middle cerebral artery occlusion (MCAO) mouse model of cerebral ischemia in vivo, organotypic hippocampal slice cultures ex vivo, and cultured neurons in vitro; the neuroprotective effects of ramelteon are diminished in MT1-knockout (KO) mice and MT1-KO cultured neurons. For the first time, we report that the MT1 receptor is significantly depleted in the brain of MCAO mice, and ramelteon treatment significantly recovers the brain MT1 losses in MCAO mice, which is further explained by the Connectivity Map L1000 bioinformatic analysis that shows gene-expression signatures of MCAO mice are negatively connected to melatonin receptor agonist like Ramelteon. We demonstrate that ramelteon improves the cerebral blood flow signals in ischemic stroke that is potentially mediated, at least, partly by mechanisms of activating endothelial nitric oxide synthase. Our results also show that the neuroprotection of ramelteon counteracts reactive oxygen species-induced oxidative stress and activates the nuclear factor erythroid 2-related factor 2/heme oxygenase-1 pathway. Ramelteon inhibits the mitochondrial and autophagic death pathways in MCAO mice and cultured neurons, consistent with gene set enrichment analysis from a bioinformatics perspective angle. Our data suggest that Ramelteon is a potential neuroprotective drug candidate, and MT1 is the neuroprotective target for ischemic stroke, which provides new insights into stroke therapy. MT1-KO mice and cultured neurons may provide animal and cellular models of accelerated ischemic damage and neuronal cell death.


Asunto(s)
Isquemia Encefálica , Indenos , Accidente Cerebrovascular Isquémico , Melatonina , Fármacos Neuroprotectores , Accidente Cerebrovascular , Animales , Ratones , Accidente Cerebrovascular Isquémico/tratamiento farmacológico , Receptor de Melatonina MT1/agonistas , Neuroprotección , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/uso terapéutico , Transducción de Señal , Melatonina/farmacología , Isquemia Encefálica/tratamiento farmacológico , Accidente Cerebrovascular/tratamiento farmacológico , Accidente Cerebrovascular/genética , Ratones Noqueados , Infarto de la Arteria Cerebral Media/tratamiento farmacológico , Infarto de la Arteria Cerebral Media/metabolismo
19.
bioRxiv ; 2023 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-37662343

RESUMEN

Glucose, the primary cellular energy source, is metabolized through glycolysis initiated by the rate-limiting enzyme Hexokinase (HK). In energy-demanding tissues like the brain, HK1 is the dominant isoform, primarily localized on mitochondria, crucial for efficient glycolysis-oxidative phosphorylation coupling and optimal energy generation. This study unveils a unique mechanism regulating HK1 activity, glycolysis, and the dynamics of mitochondrial coupling, mediated by the metabolic sensor enzyme O-GlcNAc transferase (OGT). OGT catalyzes reversible O-GlcNAcylation, a post-translational modification, influenced by glucose flux. Elevated OGT activity induces dynamic O-GlcNAcylation of HK1's regulatory domain, subsequently promoting the assembly of the glycolytic metabolon on the outer mitochondrial membrane. This modification enhances HK1's mitochondrial association, orchestrating glycolytic and mitochondrial ATP production. Mutations in HK1's O-GlcNAcylation site reduce ATP generation, affecting synaptic functions in neurons. The study uncovers a novel pathway that bridges neuronal metabolism and mitochondrial function via OGT and the formation of the glycolytic metabolon, offering new prospects for tackling metabolic and neurological disorders.

20.
J Am Acad Orthop Surg ; 31(23): 1173-1179, 2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-37671415

RESUMEN

INTRODUCTION: Artificial intelligence (AI) programs have the ability to answer complex queries including medical profession examination questions. The purpose of this study was to compare the performance of orthopaedic residents (ortho residents) against Chat Generative Pretrained Transformer (ChatGPT)-3.5 and GPT-4 on orthopaedic assessment examinations. A secondary objective was to perform a subgroup analysis comparing the performance of each group on questions that included image interpretation versus text-only questions. METHODS: The ResStudy orthopaedic examination question bank was used as the primary source of questions. One hundred eighty questions and answer choices from nine different orthopaedic subspecialties were directly input into ChatGPT-3.5 and then GPT-4. ChatGPT did not have consistently available image interpretation, so no images were directly provided to either AI format. Answers were recorded as correct versus incorrect by the chatbot, and resident performance was recorded based on user data provided by ResStudy. RESULTS: Overall, ChatGPT-3.5, GPT-4, and ortho residents scored 29.4%, 47.2%, and 74.2%, respectively. There was a difference among the three groups in testing success, with ortho residents scoring higher than ChatGPT-3.5 and GPT-4 ( P < 0.001 and P < 0.001). GPT-4 scored higher than ChatGPT-3.5 ( P = 0.002). A subgroup analysis was performed by dividing questions into question stems without images and question stems with images. ChatGPT-3.5 was more correct (37.8% vs. 22.4%, respectively, OR = 2.1, P = 0.033) and ChatGPT-4 was also more correct (61.0% vs. 35.7%, OR = 2.8, P < 0.001), when comparing text-only questions versus questions with images. Residents were 72.6% versus 75.5% correct with text-only questions versus questions with images, with no significant difference ( P = 0.302). CONCLUSION: Orthopaedic residents were able to answer more questions accurately than ChatGPT-3.5 and GPT-4 on orthopaedic assessment examinations. GPT-4 is superior to ChatGPT-3.5 for answering orthopaedic resident assessment examination questions. Both ChatGPT-3.5 and GPT-4 performed better on text-only questions than questions with images. It is unlikely that GPT-4 or ChatGPT-3.5 would pass the American Board of Orthopaedic Surgery written examination.


Asunto(s)
Inteligencia Artificial , Ortopedia , Humanos , Examen Físico , Programas Informáticos
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