Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.523
Filtrar
1.
Nat Immunol ; 25(1): 155-165, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38102487

RESUMEN

In mouse peritoneal and other serous cavities, the transcription factor GATA6 drives the identity of the major cavity resident population of macrophages, with a smaller subset of cavity-resident macrophages dependent on the transcription factor IRF4. Here we showed that GATA6+ macrophages in the human peritoneum were rare, regardless of age. Instead, more human peritoneal macrophages aligned with mouse CD206+ LYVE1+ cavity macrophages that represent a differentiation stage just preceding expression of GATA6. A low abundance of CD206+ macrophages was retained in C57BL/6J mice fed a high-fat diet and in wild-captured mice, suggesting that differences between serous cavity-resident macrophages in humans and mice were not environmental. IRF4-dependent mouse serous cavity macrophages aligned closely with human CD1c+CD14+CD64+ peritoneal cells, which, in turn, resembled human peritoneal CD1c+CD14-CD64- cDC2. Thus, major populations of serous cavity-resident mononuclear phagocytes in humans and mice shared common features, but the proportions of different macrophage differentiation stages greatly differ between the two species, and dendritic cell (DC2)-like cells were especially prominent in humans.


Asunto(s)
Macrófagos Peritoneales , Macrófagos , Humanos , Ratones , Animales , Ratones Endogámicos C57BL , Macrófagos/metabolismo , Macrófagos Peritoneales/metabolismo , Diferenciación Celular , Células Dendríticas
2.
Cell ; 184(19): 4981-4995.e14, 2021 09 16.
Artículo en Inglés | MEDLINE | ID: mdl-34464586

RESUMEN

Poor tumor infiltration, development of exhaustion, and antigen insufficiency are common mechanisms that limit chimeric antigen receptor (CAR)-T cell efficacy. Delivery of pattern recognition receptor agonists is one strategy to improve immune function; however, targeting these agonists to immune cells is challenging, and off-target signaling in cancer cells can be detrimental. Here, we engineer CAR-T cells to deliver RN7SL1, an endogenous RNA that activates RIG-I/MDA5 signaling. RN7SL1 promotes expansion and effector-memory differentiation of CAR-T cells. Moreover, RN7SL1 is deployed in extracellular vesicles and selectively transferred to immune cells. Unlike other RNA agonists, transferred RN7SL1 restricts myeloid-derived suppressor cell (MDSC) development, decreases TGFB in myeloid cells, and fosters dendritic cell (DC) subsets with costimulatory features. Consequently, endogenous effector-memory and tumor-specific T cells also expand, allowing rejection of solid tumors with CAR antigen loss. Supported by improved endogenous immunity, CAR-T cells can now co-deploy peptide antigens with RN7SL1 to enhance efficacy, even when heterogenous CAR antigen tumors lack adequate neoantigens.


Asunto(s)
Factores Inmunológicos/farmacología , ARN/farmacología , Receptores Quiméricos de Antígenos/inmunología , Linfocitos T/inmunología , Animales , Antígenos/metabolismo , Linfocitos T CD8-positivos/inmunología , Línea Celular Tumoral , Proteína 58 DEAD Box/metabolismo , Células Dendríticas/efectos de los fármacos , Células Dendríticas/metabolismo , Vesículas Extracelulares/metabolismo , Humanos , Inmunidad/efectos de los fármacos , Inmunocompetencia , Memoria Inmunológica , Inmunoterapia , Interferones/metabolismo , Melanoma Experimental/patología , Ratones Endogámicos C57BL , Células Mieloides/efectos de los fármacos , Células Mieloides/metabolismo , Péptidos/metabolismo , Receptores de Reconocimiento de Patrones/metabolismo , Linfocitos T/efectos de los fármacos
3.
Cell ; 181(2): 306-324.e28, 2020 04 16.
Artículo en Inglés | MEDLINE | ID: mdl-32302570

RESUMEN

Liquid-liquid phase separation (LLPS) mediates formation of membraneless condensates such as those associated with RNA processing, but the rules that dictate their assembly, substructure, and coexistence with other liquid-like compartments remain elusive. Here, we address the biophysical mechanism of this multiphase organization using quantitative reconstitution of cytoplasmic stress granules (SGs) with attached P-bodies in human cells. Protein-interaction networks can be viewed as interconnected complexes (nodes) of RNA-binding domains (RBDs), whose integrated RNA-binding capacity determines whether LLPS occurs upon RNA influx. Surprisingly, both RBD-RNA specificity and disordered segments of key proteins are non-essential, but modulate multiphase condensation. Instead, stoichiometry-dependent competition between protein networks for connecting nodes determines SG and P-body composition and miscibility, while competitive binding of unconnected proteins disengages networks and prevents LLPS. Inspired by patchy colloid theory, we propose a general framework by which competing networks give rise to compositionally specific and tunable condensates, while relative linkage between nodes underlies multiphase organization.


Asunto(s)
Gránulos Citoplasmáticos/fisiología , Estructuras Citoplasmáticas/fisiología , Mapas de Interacción de Proteínas/fisiología , Fenómenos Biofísicos , Línea Celular Tumoral , Citoplasma/metabolismo , Humanos , Proteínas Intrínsecamente Desordenadas/genética , Extracción Líquido-Líquido/métodos , Orgánulos/química , ARN/metabolismo , Proteínas con Motivos de Reconocimiento de ARN/metabolismo , Proteínas con Motivos de Reconocimiento de ARN/fisiología
4.
Cell ; 175(6): 1481-1491.e13, 2018 11 29.
Artículo en Inglés | MEDLINE | ID: mdl-30500535

RESUMEN

Phase transitions involving biomolecular liquids are a fundamental mechanism underlying intracellular organization. In the cell nucleus, liquid-liquid phase separation of intrinsically disordered proteins (IDPs) is implicated in assembly of the nucleolus, as well as transcriptional clusters, and other nuclear bodies. However, it remains unclear whether and how physical forces associated with nucleation, growth, and wetting of liquid condensates can directly restructure chromatin. Here, we use CasDrop, a novel CRISPR-Cas9-based optogenetic technology, to show that various IDPs phase separate into liquid condensates that mechanically exclude chromatin as they grow and preferentially form in low-density, largely euchromatic regions. A minimal physical model explains how this stiffness sensitivity arises from lower mechanical energy associated with deforming softer genomic regions. Targeted genomic loci can nonetheless be mechanically pulled together through surface tension-driven coalescence. Nuclear condensates may thus function as mechano-active chromatin filters, physically pulling in targeted genomic loci while pushing out non-targeted regions of the neighboring genome. VIDEO ABSTRACT.


Asunto(s)
Nucléolo Celular/metabolismo , Cromatina/metabolismo , Citoplasma/metabolismo , Genoma Humano , Proteínas Intrínsecamente Desordenadas/metabolismo , Transición de Fase , Animales , Línea Celular Tumoral , Femenino , Células HEK293 , Humanos , Masculino , Ratones , Células 3T3 NIH
5.
Mol Cell ; 83(17): 3095-3107.e9, 2023 09 07.
Artículo en Inglés | MEDLINE | ID: mdl-37683610

RESUMEN

The nucleolus is the largest biomolecular condensate and facilitates transcription, processing, and assembly of ribosomal RNA (rRNA). Although nucleolar function is thought to require multiphase liquid-like properties, nucleolar fluidity and its connection to the highly coordinated transport and biogenesis of ribosomal subunits are poorly understood. Here, we use quantitative imaging, mathematical modeling, and pulse-chase nucleotide labeling to examine nucleolar material properties and rRNA dynamics. The mobility of rRNA is several orders of magnitude slower than that of nucleolar proteins, with rRNA steadily moving away from the transcriptional sites in a slow (∼1 Å/s), radially directed fashion. This constrained but directional mobility, together with polymer physics-based calculations, suggests that nascent rRNA forms an entangled gel, whose constant production drives outward flow. We propose a model in which progressive maturation of nascent rRNA reduces its initial entanglement, fluidizing the nucleolar periphery to facilitate the release of assembled pre-ribosomal particles.


Asunto(s)
ARN Ribosómico , ARN , ARN/genética , ARN Ribosómico/genética , Condensados Biomoleculares , Nucléolo Celular/genética , Proteínas Nucleares/genética
7.
Proc Natl Acad Sci U S A ; 121(19): e2318413121, 2024 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-38683993

RESUMEN

Determining the pathogenicity of hypertrophic cardiomyopathy-associated mutations in the ß-myosin heavy chain (MYH7) can be challenging due to its variable penetrance and clinical severity. This study investigates the early pathogenic effects of the incomplete-penetrant MYH7 G256E mutation on myosin function that may trigger pathogenic adaptations and hypertrophy. We hypothesized that the G256E mutation would alter myosin biomechanical function, leading to changes in cellular functions. We developed a collaborative pipeline to characterize myosin function across protein, myofibril, cell, and tissue levels to determine the multiscale effects on structure-function of the contractile apparatus and its implications for gene regulation and metabolic state. The G256E mutation disrupts the transducer region of the S1 head and reduces the fraction of myosin in the folded-back state by 33%, resulting in more myosin heads available for contraction. Myofibrils from gene-edited MYH7WT/G256E human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) exhibited greater and faster tension development. This hypercontractile phenotype persisted in single-cell hiPSC-CMs and engineered heart tissues. We demonstrated consistent hypercontractile myosin function as a primary consequence of the MYH7 G256E mutation across scales, highlighting the pathogenicity of this gene variant. Single-cell transcriptomic and metabolic profiling demonstrated upregulated mitochondrial genes and increased mitochondrial respiration, indicating early bioenergetic alterations. This work highlights the benefit of our multiscale platform to systematically evaluate the pathogenicity of gene variants at the protein and contractile organelle level and their early consequences on cellular and tissue function. We believe this platform can help elucidate the genotype-phenotype relationships underlying other genetic cardiovascular diseases.


Asunto(s)
Miosinas Cardíacas , Cardiomiopatía Hipertrófica , Células Madre Pluripotentes Inducidas , Contracción Miocárdica , Miocitos Cardíacos , Cadenas Pesadas de Miosina , Humanos , Cadenas Pesadas de Miosina/genética , Cadenas Pesadas de Miosina/metabolismo , Miosinas Cardíacas/genética , Miosinas Cardíacas/metabolismo , Cardiomiopatía Hipertrófica/genética , Cardiomiopatía Hipertrófica/metabolismo , Células Madre Pluripotentes Inducidas/metabolismo , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , Contracción Miocárdica/genética , Mutación , Mitocondrias/metabolismo , Mitocondrias/genética , Miofibrillas/metabolismo , Respiración de la Célula/genética
8.
Proc Natl Acad Sci U S A ; 120(21): e2219778120, 2023 05 23.
Artículo en Inglés | MEDLINE | ID: mdl-37186825

RESUMEN

Cells mediate interactions with the extracellular environment through a crowded assembly of transmembrane proteins, glycoproteins and glycolipids on their plasma membrane. The extent to which surface crowding modulates the biophysical interactions of ligands, receptors, and other macromolecules is poorly understood due to the lack of methods to quantify surface crowding on native cell membranes. In this work, we demonstrate that physical crowding on reconstituted membranes and live cell surfaces attenuates the effective binding affinity of macromolecules such as IgG antibodies in a surface crowding-dependent manner. We combine experiment and simulation to design a crowding sensor based on this principle that provides a quantitative readout of cell surface crowding. Our measurements reveal that surface crowding decreases IgG antibody binding by 2 to 20 fold in live cells compared to a bare membrane surface. Our sensors show that sialic acid, a negatively charged monosaccharide, contributes disproportionately to red blood cell surface crowding via electrostatic repulsion, despite occupying only ~1% of the total cell membrane by mass. We also observe significant differences in surface crowding for different cell types and find that expression of single oncogenes can both increase and decrease crowding, suggesting that surface crowding may be an indicator of both cell type and state. Our high-throughput, single-cell measurement of cell surface crowding may be combined with functional assays to enable further biophysical dissection of the cell surfaceome.


Asunto(s)
Eritrocitos , Proteínas de la Membrana , Membrana Celular/metabolismo , Proteínas de la Membrana/metabolismo , Sustancias Macromoleculares/metabolismo , Eritrocitos/metabolismo
9.
J Virol ; 98(4): e0060323, 2024 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-38517165

RESUMEN

Herpesviruses replicate by cleaving concatemeric dsDNA into single genomic units that are packaged through an oligomeric portal present in preformed procapsids. In contrast to what is known about phage portal proteins, details concerning herpesvirus portal structure and function are not as well understood. A panel of 65 Varicella-Zoster virus (VZV) recombinant portal proteins with five amino acid in-frame insertions were generated by random transposon mutagenesis of the VZV portal gene, ORF54. Subsequently, 65 VZVLUC recombinant viruses (TNs) were generated via recombineering. Insertions were mapped to predicted portal domains (clip, wing, stem, wall, crown, and ß-hairpin tunnel-loop) and recombinant viruses were characterized for plaque morphology, replication kinetics, pORF54 expression, and classified based on replication in non-complementing (ARPE19) or complementing (ARPE54C50) cell lines. The N- and C-termini were tolerant to insertion mutagenesis, as were certain clip sub-domains. The majority of mutants mapping to the wing, wall, ß-hairpin tunnel loop, and stem domains were lethal. Elimination of the predicted ORF54 start codon revealed that the first 40 amino acids of the N-terminus were not required for viral replication. Stop codon insertions in the C-terminus showed that the last 100 amino acids were not required for viral replication. Lastly, a putative protease cleavage site was identified in the C-terminus of pORF54. Cleavage was likely orchestrated by a viral protease; however, processing was not required for DNA encapsidation and viral replication. The panel of recombinants should prove valuable in future studies to dissect mammalian portal structure and function.IMPORTANCEThough nucleoside analogs and a live-attenuated vaccine are currently available to treat some human herpesvirus family members, alternate methods of combating herpesvirus infection could include blocking viral replication at the DNA encapsidation stage. The approval of Letermovir provided proof of concept regarding the use of encapsidation inhibitors to treat herpesvirus infections in the clinic. We propose that small-molecule compounds could be employed to interrupt portal oligomerization, assembly into the capsid vertex, or affect portal function/dynamics. Targeting portal at any of these steps would result in disruption of viral DNA packaging and a decrease or absence of mature infectious herpesvirus particles. The oligomeric portals of herpesviruses are structurally conserved, and therefore, it may be possible to find a single compound capable of targeting portals from one or more of the herpesvirus subfamilies. Drug candidates from such a series would be effective against viruses resistant to the currently available antivirals.


Asunto(s)
Infecciones por Herpesviridae , Herpesvirus Humano 3 , Animales , Humanos , Herpesvirus Humano 3/genética , Herpesvirus Humano 3/metabolismo , Mutagénesis , Replicación Viral , Infecciones por Herpesviridae/genética , ADN/metabolismo , Aminoácidos/genética , Mamíferos/genética
10.
J Neurosci ; 43(25): 4612-4624, 2023 06 21.
Artículo en Inglés | MEDLINE | ID: mdl-37117012

RESUMEN

A key mode of neuronal communication between distant brain regions is through excitatory synaptic transmission mediated by long-range glutamatergic projections emitted from principal neurons. The long-range glutamatergic projection normally forms numerous en passant excitatory synapses onto both principal neurons and interneurons along its path. Under physiological conditions, the monosynaptic excitatory drive onto postsynaptic principal neurons outweighs disynaptic feedforward inhibition, with the net effect of depolarizing principal neurons. In contrast with this conventional doctrine, here we report that a glutamatergic projection from the hypothalamic supramammillary nucleus (SuM) largely evades postsynaptic pyramidal neurons (PNs), but preferentially target interneurons in the hippocampal CA3 region to predominantly provide feedforward inhibition. Using viral-based retrograde and anterograde tracing and ChannelRhodopsin2 (ChR2)-assisted patch-clamp recording in mice of either sex, we show that SuM projects sparsely to CA3 and provides minimal excitation onto CA3 PNs. Surprisingly, despite its sparse innervation, the SuM input inhibits all CA3 PNs along the transverse axis. Further, we find that SuM provides strong monosynaptic excitation onto CA3 parvalbumin-expressing interneurons evenly along the transverse axis, which likely mediates the SuM-driven feedforward inhibition. Together, our results demonstrate that a novel long-range glutamatergic pathway largely evades principal neurons, but rather preferentially innervates interneurons in a distant brain region to suppress principal neuron activity. Moreover, our findings reveal a new means by which SuM regulates hippocampal activity through SuM-to-CA3 circuit, independent of the previously focused projections from SuM to CA2 or dentate gyrus.SIGNIFICANCE STATEMENT The dominant mode of neuronal communication between brain regions is the excitatory synaptic transmission mediated by long-range glutamatergic projections, which form en passant excitatory synapses onto both pyramidal neurons and interneurons along its path. Under normal conditions, the excitation onto postsynaptic neurons outweighs feedforward inhibition, with the net effect of depolarization. In contrast with this conventional doctrine, here we report that a glutamatergic input from hypothalamic supramammillary nucleus (SuM) largely evades PNs but selectively targets interneurons to almost exclusively provide disynaptic feedforward inhibition onto hippocampal CA3 PNs. Thus, our findings reveal a novel subcortical-hippocampal circuit that enables SuM to regulate hippocampal activity via SuM-CA3 circuit, independent of its projections to CA2 or dentate gyrus.


Asunto(s)
Interneuronas , Células Piramidales , Ratones , Animales , Células Piramidales/fisiología , Interneuronas/fisiología , Neuronas/fisiología , Hipocampo/fisiología , Hipotálamo Posterior
11.
Clin Infect Dis ; 2024 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-38501237

RESUMEN

BACKGROUND: Weight gain and associated metabolic complications are increasingly prevalent among people with HIV (PWH). Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are incretin-based therapies for diabetes and weight management that have been shown to result in substantial weight loss; however, studies of their effects in PWH are limited. METHODS: A retrospective single-center cohort study was conducted among PWH who were taking GLP-1RAs at UC San Diego Owen Clinic between 2/1/2021 to 2/1/2023. Baseline clinical data were collected and changes in weight, body mass index (BMI), and hemoglobin A1C (A1C) before starting GLP-1RAs compared to the most recent clinic visit were calculated (with a minimum of 3 months follow-up time required). Logistic regression was performed to identify variables associated with >5% of total body weight loss. RESULTS: A total of 225 patients received on average 13 months of GLP-1RA therapy, with 85 (37.8%) achieving the maximum GLP-1RA dose. GLP-1RA therapy resulted, on average, in a loss of 5.4 kg, decrease in BMI by 1.8 kg/m2, and decrease in A1C by 0.6%. In the multivariable analysis, higher baseline BMI [OR 1.10 (1.03-1.16)], treatment duration of GLP-1RA therapy greater than 6 months [OR 3.12 (1.49-6.49], and use of tirzepatide [OR 5.46 (1.44-20.76)] were significantly more likely to be associated with >5% weight loss. CONCLUSIONS: Use of GLP-1RAs led to declines in weight, BMI, and hemoglobin A1C among PWH and offers an additional strategy to address weight gain and diabetes.

12.
J Am Chem Soc ; 146(20): 14048-14057, 2024 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-38713054

RESUMEN

Optimization of active sites and stability under irradiation are important targets for sorbent materials that might be used for iodine (I2) storage. Herein, we report the direct observation of I2 binding in a series of Cu(II)-based isostructural metal-organic frameworks, MFM-170, MFM-172, MFM-174, NJU-Bai20, and NJU-Bai21, incorporating various functional groups (-H, -CH3, - NH2, -C≡C-, and -CONH-, respectively). MFM-170 shows a reversible uptake of 3.37 g g-1 and a high packing density of 4.41 g cm-3 for physiosorbed I2. The incorporation of -NH2 and -C≡C- moieties in MFM-174 and NJU-Bai20, respectively, enhances the binding of I2, affording uptakes of up to 3.91 g g-1. In addition, an exceptional I2 packing density of 4.83 g cm-3 is achieved in MFM-174, comparable to that of solid iodine (4.93 g cm-3). In situ crystallographic studies show the formation of a range of supramolecular and chemical interactions [I···N, I···H2N] and [I···C≡C, I-C═C-I] between -NH2, -C≡C- sites, respectively, and adsorbed I2 molecules. These observations have been confirmed via a combination of solid-state nuclear magnetic resonance, X-ray photoelectron, and Raman spectroscopies. Importantly, γ-irradiation confirmed the ultraresistance of MFM-170, MFM-174, and NJU-Bai20 suggesting their potential as efficient sorbents for cleanup of radioactive waste.

13.
Annu Rev Pharmacol Toxicol ; 61: 113-134, 2021 01 06.
Artículo en Inglés | MEDLINE | ID: mdl-32776859

RESUMEN

Immune checkpoint inhibitors (ICIs) attenuate mechanisms of self-tolerance in the immune system, enabling T cell responses to cancerous tissues and revolutionizing care for cancer patients. However, by loweringbarriers against self-reactivity, ICIs often result in varying degrees of autoimmunity. Cardiovascular complications, particularly myocarditis but also arrhythmias, pericarditis, and vasculitis, have emerged as significant complications associated with ICIs. In this review, we examine the clinical aspects and basic science principles that underlie ICI-associated myocarditis and other cardiovascular toxicities. In addition, we discuss current therapeutic approaches. We believe a better mechanistic understanding of ICI-associated toxicities can lead to improved patient outcomes by reducing treatment-related morbidity.


Asunto(s)
Sistema Cardiovascular , Miocarditis , Neoplasias , Cardiotoxicidad , Humanos , Inhibidores de Puntos de Control Inmunológico , Miocarditis/tratamiento farmacológico , Neoplasias/tratamiento farmacológico
14.
Lancet ; 401(10375): 458-469, 2023 02 11.
Artículo en Inglés | MEDLINE | ID: mdl-36774155

RESUMEN

BACKGROUND: Guidelines recommend effective on-demand therapy for all individuals with hereditary angioedema. We aimed to assess the novel oral plasma kallikrein inhibitor, sebetralstat, which is in development, for on-demand treatment of hereditary angioedema attacks. METHODS: In this two-part phase 2 trial, individuals with type 1 or 2 hereditary angioedema aged 18 years or older were recruited from 25 sites, consisting of specialty outpatient centres, across nine countries in Europe and the USA. Individuals were eligible if they had experienced at least three hereditary angioedema attacks in the past 93 days, were not on prophylactic therapy, and had access to and the ability to self-administer conventional attack treatment. In part 1 of the trial, participants were given a single 600 mg open-label oral dose of sebetralstat to assess safety, pharmacokinetics, and pharmacodynamics of the dose. Part 2 was a randomised, double-blind, placebo-controlled, two-sequence, two-period (2 × 2) crossover trial; participants were randomly assigned (1:1) to either sequence 1, in which they were given a single dose of 600 mg of sebetralstat to treat the first eligible attack and a second dose of placebo to treat the second eligible attack, or sequence 2, in which they were given placebo to treat the first eligible attack and then 600 mg of sebetralstat to treat the second eligible attack. Participants and investigators were masked to treatment assignment. The primary endpoint was time to use of conventional attack treatment within 12 h of study drug administration, which was assessed in all participants who were randomly assigned to treatment and who received study drug for two attacks during part 2 of the study. Safety was assessed in all participants who received at least one dose of study drug, starting in part 1. This study is registered with ClinicalTrials.gov, NCT04208412, and is completed. FINDINGS: Between July 2, 2019, and Dec 8, 2020, 84 individuals were screened and 68 were enrolled in part 1 and received sebetralstat (mean age 38·3 years [SD 13·2], 37 [54%] were female, 31 [46%] were male, 68 [100%] were White). 42 (62%) of 68 participants completed pharmacokinetic assessments. Sebetralstat was rapidly absorbed, with a geometric mean plasma concentration of 501 ng/mL at 15 min. In a subset of participants (n=6), plasma samples obtained from 15 min to 4 h after study drug administration had near-complete protection from ex vivo stimulated generation of plasma kallikrein and cleavage of high-molecular-weight kininogen. In part 2, all 68 participants were randomly assigned to sequence 1 (n=34) or sequence 2 (n=34). 53 (78%) of 68 participants treated two attacks (25 [74%] in the sequence 1 group and 28 [82%] in the sequence 2 group). Time to use of conventional treatment within 12 h of study drug administration was significantly longer with sebetralstat versus placebo (at quartile 1: >12 h [95% CI 9·6 to >12] vs 8·0 h [3·8 to >12]; p=0·0010). There were no serious adverse events or adverse event-related discontinuations. INTERPRETATION: Oral administration of sebetralstat was well tolerated and led to rapid suppression of plasma kallikrein activity, resulting in increased time to use of conventional attack treatment and faster symptom relief versus placebo. Based on these results, a phase 3 trial to evaluate the efficacy and safety of two dose levels of sebetralstat in adolescent and adult participants with hereditary angioedema has been initiated (NCT05259917). FUNDING: KalVista Pharmaceuticals.


Asunto(s)
Angioedemas Hereditarios , Calicreína Plasmática , Adulto , Femenino , Humanos , Masculino , Angioedemas Hereditarios/tratamiento farmacológico , Angioedemas Hereditarios/prevención & control , Estudios Cruzados , Método Doble Ciego , Calicreína Plasmática/antagonistas & inhibidores , Resultado del Tratamiento , Persona de Mediana Edad
15.
Small ; : e2309984, 2024 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-38497489

RESUMEN

Among diverse chemical synthetic approaches to zinc oxide nanocrystals (ZnO NCs), ubiquitous inorganic sol-gel methodology proved crucial for advancements in ZnO-based nanoscience. Strikingly, unlike the exquisite level of control over morphology and size dispersity achieved in ZnO NC syntheses, the purity of the crystalline phase, as well as the understanding of the surface structure and the character of the inorganic-organic interface, have been limited to vague descriptors until very recently. Herein, ZnO NCs applying the standard sol-gel synthetic protocol are synthesized with zinc acetate and lithium hydroxide and tracked the integration of lithium (Li) cations into the interior and exterior of nanoparticles by combining various techniques, including advanced solid-state NMR methods. In contrast to common views, it is demonstrated that Li+ ions remain kinetically trapped in the inorganic core, enter into a shallow subsurface layer, and generate "swelling" of the surface and interface regions. Thus, this work enabled both the determination of the NCs' structural imperfections and an in-depth understanding of the unappreciated role of the Li+ ions in impacting the doping and the passivation of sol-gel-derived ZnO nanomaterials.

16.
Proc Biol Sci ; 291(2015): 20231699, 2024 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-38264780

RESUMEN

Dragonfly nymphs breathe water using tidal ventilation, a highly unusual strategy in water-breathing animals owing to the high viscosity, density and low oxygen (O2) concentration of water. This study examines how well these insects extract O2 from the surrounding water during progressive hypoxia. Nymphs were attached to a custom-designed respiro-spirometer to simultaneously measure tidal volume, ventilation frequency and metabolic rate. Oxygen extraction efficiencies (OEE) were calculated across four partial pressure of oxygen (pO2) treatments, from normoxia to severe hypoxia. While there was no significant change in tidal volume, ventilation frequency increased significantly from 9.4 ± 1.2 breaths per minute (BPM) at 21.3 kPa to 35.6 ± 2.9 BPM at 5.3 kPa. Metabolic rate increased significantly from 1.4 ± 0.3 µl O2 min-1 at 21.3 kPa to 2.1 ± 0.4 µl O2 min-1 at 16.0 kPa, but then returned to normoxic levels as O2 levels declined further. OEE of nymphs was 40.1 ± 6.1% at 21.3 kPa, and did not change significantly during hypoxia. Comparison to literature shows that nymphs maintain their OEE during hypoxia unlike other aquatic tidal-breathers and some unidirectional breathers. This result, and numerical models simulating experimental conditions, indicate that nymphs maintain these extraction efficiencies by increasing gill conductance and/or lowering internal pO2 to maintain a sufficient diffusion gradient across their respiratory surface.


Asunto(s)
Branquias , Odonata , Animales , Hipoxia , Oxígeno , Ninfa , Agua
17.
Blood ; 140(5): 451-463, 2022 08 04.
Artículo en Inglés | MEDLINE | ID: mdl-35605184

RESUMEN

Remission durability following single-antigen targeted chimeric antigen receptor (CAR) T-cells is limited by antigen modulation, which may be overcome with combinatorial targeting. Building upon our experiences targeting CD19 and CD22 in B-cell acute lymphoblastic leukemia (B-ALL), we report on our phase 1 dose-escalation study of a novel murine stem cell virus (MSCV)-CD19/CD22-4-1BB bivalent CAR T-cell (CD19.22.BBζ) for children and young adults (CAYA) with B-cell malignancies. Primary objectives included toxicity and dose finding. Secondary objectives included response rates and relapse-free survival (RFS). Biologic correlatives included laboratory investigations, CAR T-cell expansion and cytokine profiling. Twenty patients, ages 5.4 to 34.6 years, with B-ALL received CD19.22.BBζ. The complete response (CR) rate was 60% (12 of 20) in the full cohort and 71.4% (10 of 14) in CAR-naïve patients. Ten (50%) developed cytokine release syndrome (CRS), with 3 (15%) having ≥ grade 3 CRS and only 1 experiencing neurotoxicity (grade 3). The 6- and 12-month RFS in those achieving CR was 80.8% (95% confidence interval [CI]: 42.4%-94.9%) and 57.7% (95% CI: 22.1%-81.9%), respectively. Limited CAR T-cell expansion and persistence of MSCV-CD19.22.BBζ compared with EF1α-CD22.BBζ prompted laboratory investigations comparing EF1α vs MSCV promoters, which did not reveal major differences. Limited CD22 targeting with CD19.22.BBζ, as evaluated by ex vivo cytokine secretion and leukemia eradication in humanized mice, led to development of a novel bicistronic CD19.28ζ/CD22.BBζ construct with enhanced cytokine production against CD22. With demonstrated safety and efficacy of CD19.22.BBζ in a heavily pretreated CAYA B-ALL cohort, further optimization of combinatorial antigen targeting serves to overcome identified limitations (www.clinicaltrials.gov #NCT03448393).


Asunto(s)
Linfoma de Burkitt , Linfoma de Células B , Leucemia-Linfoma Linfoblástico de Células Precursoras , Receptores Quiméricos de Antígenos , Animales , Antígenos CD19 , Síndrome de Liberación de Citoquinas , Citocinas , Humanos , Inmunoterapia Adoptiva/efectos adversos , Inmunoterapia Adoptiva/métodos , Ratones , Receptores de Antígenos de Linfocitos T/genética , Receptores Quiméricos de Antígenos/genética , Recurrencia , Linfocitos T
18.
NMR Biomed ; 37(3): e5059, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37872862

RESUMEN

While single-shot late gadolinium enhancement (LGE) is useful for imaging patients with arrhythmia and/or dyspnea, it produces low spatial resolution. One approach to improve spatial resolution is to accelerate data acquisition using compressed sensing (CS). Our previous work described a single-shot, multi-inversion time (TI) LGE pulse sequence using radial k-space sampling and CS, but over-regularization resulted in significant image blurring that muted the benefits of data acceleration. The purpose of the present study was to improve the spatial resolution of the single-shot, multi-TI LGE pulse sequence by incorporating view sharing (VS) and k-space weighted contrast (KWIC) filtering into a GRASP-Pro reconstruction. In 24 patients (mean age = 61 ± 16 years; 9/15 females/males), we compared the performance of our improved multi-TI LGE and standard multi-TI LGE, where clinical standard LGE was used as a reference. Two clinical raters independently graded multi-TI images and clinical LGE images visually on a five-point Likert scale (1, nondiagnostic; 3, clinically acceptable; 5, best) for three categories: the conspicuity of myocardium or scar, artifact, and noise. The summed visual score (SVS) was defined as the sum of the three scores. Myocardial scar volume was quantified using the full-width at half-maximum method. The SVS was not significantly different between clinical breath-holding LGE (median 13.5, IQR 1.3) and multi-TI LGE (median 12.5, IQR 1.6) (P = 0.068). The myocardial scar volumes measured from clinical standard LGE and multi-TI LGE were strongly correlated (coefficient of determination, R2 = 0.99) and in good agreement (mean difference = 0.11%, lower limit of the agreement = -2.13%, upper limit of the agreement = 2.34%). The inter-rater agreement in myocardial scar volume quantification was strong (intraclass correlation coefficient = 0.79). The incorporation of VS and KWIC into GRASP-Pro improved spatial resolution. Our improved 25-fold accelerated, single-shot LGE sequence produces clinically acceptable image quality, multi-TI reconstruction, and accurate myocardial scar volume quantification.


Asunto(s)
Medios de Contraste , Gadolinio , Masculino , Femenino , Humanos , Persona de Mediana Edad , Anciano , Cicatriz/patología , Imagen por Resonancia Magnética/métodos , Miocardio/patología
19.
Chemistry ; 30(20): e202303934, 2024 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-38102961

RESUMEN

The selective capture of methane (CH4) at low concentrations and its separation from N2 are extremely challenging owing to the weak host-guest interactions between CH4 molecules and any sorbent material. Here, we report the exceptional adsorption of CH4 at low pressure and the efficient separation of CH4/N2 by MFM-300(Fe). MFM-300(Fe) shows a very high uptake for CH4 of 0.85 mmol g-1 at 1 mbar and 298 K and a record CH4/N2 selectivity of 45 for porous solids, representing a new benchmark for CH4 capture and CH4/N2 separation. The excellent separation of CH4/N2 by MFM-300(Fe) has been confirmed by dynamic breakthrough experiments. In situ neutron powder diffraction, and solid-state nuclear magnetic resonance and diffuse reflectance infrared Fourier transform spectroscopies, coupled with modelling, reveal a unique and strong binding of CH4 molecules involving Fe-OH⋯CH4 and C⋯phenyl ring interactions within the pores of MFM-300(Fe), thus promoting the exceptional adsorption of CH4 at low pressure.

20.
Chemistry ; 30(7): e202303289, 2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-37899311

RESUMEN

Formamides are important feedstocks for the manufacture of many fine chemicals. State-of-the-art synthesis of formamides relies on the use of an excess amount of reagents, giving copious waste and thus poor atom-economy. Here, we report the first example of direct synthesis of N-formamides by coupling two challenging reactions, namely reductive amination of carbonyl compounds, particularly biomass-derived aldehydes and ketones, and fixation of CO2 in the presence of H2 over a metal-organic framework supported ruthenium catalyst, Ru/MFM-300(Cr). Highly selective production of N-formamides has been observed for a wide range of carbonyl compounds. Synchrotron X-ray powder diffraction reveals the presence of strong host-guest binding interactions via hydrogen bonding and parallel-displaced π⋅⋅⋅π interactions between the catalyst and adsorbed substrates facilitating the activation of substrates and promoting selectivity to formamides. The use of multifunctional porous catalysts to integrate CO2 utilisation in the synthesis of formamide products will have a significant impact in the sustainable synthesis of feedstock chemicals.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA