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1.
J Neurosci ; 44(29)2024 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-38866486

RESUMEN

We investigated sex differences in dopamine (DA) release in the nucleus accumbens (NAc) and dorsolateral striatum (DLS) using a chronic 16-channel carbon fiber electrode and fast-scan cyclic voltammetry (FSCV). Electrical stimulation-induced (ES; 60 Hz) DA release was recorded in the NAc of single- or pair-housed male and female rats. When core (NAcC) and shell (NAcS) were recorded simultaneously, there was greater ES DA release in NAcC of pair-housed females compared with single females and males. Housing did not affect ES NAc DA release in males. In contrast, there was significantly more ES DA release from the DLS of female rats than male rats. This was true prior to and after treatment with methamphetamine. Furthermore, in castrated (CAST) males and ovariectomized (OVX) females, there were no sex differences in ES DA release from the DLS, demonstrating the hormone dependence of this sex difference. However, in the DLS of both intact and gonadectomized rats, DA reuptake was slower in females than that in males. Finally, DA release following ES of the medial forebrain bundle at 60 Hz was studied over 4 weeks. ES DA release increased over time for both CAST males and OVX females, demonstrating sensitization. Using this novel 16-channel chronic FSCV electrode, we found sex differences in the effects of social housing in the NAcS, sex differences in DA release from intact rats in DLS, and sex differences in DA reuptake in DLS of intake and gonadectomized rats, and we report sensitization of ES-induced DA release in DLS in vivo.


Asunto(s)
Cuerpo Estriado , Dopamina , Estimulación Eléctrica , Núcleo Accumbens , Caracteres Sexuales , Animales , Masculino , Núcleo Accumbens/metabolismo , Femenino , Dopamina/metabolismo , Ratas , Cuerpo Estriado/metabolismo , Estimulación Eléctrica/métodos , Ratas Sprague-Dawley , Vivienda para Animales , Ovariectomía , Metanfetamina/farmacología
2.
J Biol Chem ; 300(11): 107825, 2024 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-39342993

RESUMEN

Our understanding of acute leukemia pathology is heavily dependent on 11q23 chromosomal translocations involving the mixed lineage leukemia-1 (MLL1) gene, a key player in histone H3 lysine 4 (H3K4) methylation. These translocations result in MLL1-fusion (MLL1F) proteins that are thought to drive leukemogenesis. However, the mechanism behind increased H3K4 trimethylation in MLL1F-leukemic stem cells (MLL1F-LSCs), following loss of the catalytic SET domain of MLL1 (known for H3K4 monomethylation and dimethylation) remains unclear. In our investigation, we introduced a homozygous loss-of-function point mutation in MLL1 within human-induced pluripotent stem cells. This mutation mimics the histone methylation, gene expression, and epithelial-mesenchymal transition phenotypes of MLL1F-LSCs-without requiring a translocation or functional WT MLL1. The mutation caused a genome-wide redistribution of the H3K4 trimethyl mark and upregulated LSC-maintenance genes like HoxA9-A13, Meis1, and the HOTTIP long noncoding RNA. Epithelial-mesenchymal transition markers such as ZEB1, SNAI2, and HIC-5 were also increased leading to enhanced cellular migration and invasiveness. These observations underscore the essential role of MLL1's enzymatic activity in restraining the cascade of epigenetic changes associated with the gene-activating H3K4 trimethylation mark, which we show may be catalyzed by mislocalized SETd1a H3K4 trimethyltransferase in the absence of MLL1's enzymatic activity. Challenging existing models, our findings imply that MLL1F-induced leukemias arise from a dominant-negative impact on MLL1's histone methyltransferase activity. We propose targeting SETd1a in precision medicine as a new therapeutic approach for MLL1-associated leukemias.

3.
Exp Cell Res ; 435(2): 113930, 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38237846

RESUMEN

The focal adhesion protein, Hic-5 plays a key role in promoting extracellular matrix deposition and remodeling by cancer associated fibroblasts within the tumor stroma to promote breast tumor cell invasion. However, whether stromal matrix gene expression is regulated by Hic-5 is still unknown. Utilizing a constitutive Hic-5 knockout, Mouse Mammary Tumor Virus-Polyoma Middle T-Antigen spontaneous breast tumor mouse model, bulk RNAseq analysis was performed on cancer associated fibroblasts isolated from Hic-5 knockout mammary tumors. Functional network analysis highlighted a key role for Hic-5 in extracellular matrix organization, with both structural matrix genes, as well as matrix remodeling genes being differentially expressed in relation to Hic-5 expression. The subcellular distribution of the MRTF-A transcription factor and expression of a subset of MRTF-A responsive genes was also impacted by Hic-5 expression. Additionally, cytokine array analysis of conditioned media from the Hic-5 and Hic-5 knockout cancer associated fibroblasts revealed that Hic-5 is important for the secretion of several key factors that are associated with matrix remodeling, angiogenesis and immune evasion. Together, these data provide further evidence of a central role for Hic-5 expression in cancer associated fibroblasts in regulating the composition and organization of the tumor stroma microenvironment to promote breast tumor progression.


Asunto(s)
Neoplasias de la Mama , Fibroblastos Asociados al Cáncer , Animales , Femenino , Humanos , Ratones , Neoplasias de la Mama/metabolismo , Fibroblastos Asociados al Cáncer/patología , Citocinas/genética , Citocinas/metabolismo , Matriz Extracelular/metabolismo , Fibroblastos/metabolismo , Expresión Génica , Proteínas con Dominio LIM/genética , Proteínas con Dominio LIM/metabolismo , Factores de Transcripción/metabolismo , Microambiente Tumoral/genética
4.
Emerg Infect Dis ; 30(5): 956-967, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38666622

RESUMEN

We estimated COVID-19 transmission potential and case burden by variant type in Alberta, British Columbia, and Ontario, Canada, during January 23, 2020-January 27, 2022; we also estimated the effectiveness of public health interventions to reduce transmission. We estimated time-varying reproduction number (Rt) over 7-day sliding windows and nonoverlapping time-windows determined by timing of policy changes. We calculated incidence rate ratios (IRRs) for each variant and compared rates to determine differences in burden among provinces. Rt corresponding with emergence of the Delta variant increased in all 3 provinces; British Columbia had the largest increase, 43.85% (95% credible interval [CrI] 40.71%-46.84%). Across the study period, IRR was highest for Omicron (8.74 [95% CrI 8.71-8.77]) and burden highest in Alberta (IRR 1.80 [95% CrI 1.79-1.81]). Initiating public health interventions was associated with lower Rt and relaxing restrictions and emergence of new variants associated with increases in Rt.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , COVID-19/epidemiología , COVID-19/transmisión , Ontario/epidemiología , Colombia Británica/epidemiología , Alberta/epidemiología , Incidencia , Número Básico de Reproducción , Salud Pública
5.
Zoo Biol ; 2024 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-39286937

RESUMEN

Zoos are under increasing pressure to strategically manage their collections to maximize visitor attendance, financial income, and their contribution to conservation. As a result, the compositions of zoo collections are undergoing significant changes. Many zoos are keeping fewer species and prioritizing keeping large flagship animals that are more attractive to the public. To understand the effects these changes are having on captive reptile numbers, we have analyzed the trends in reptile holdings between 2003 and 2023 at UK zoos. Our findings show that despite an overall increase in reptile numbers in the period analyzed, there has been a dramatic decline in the number of venomous snakes held at UK zoos, and as a result, venomous snakes are being excluded from many of the conservation benefits that zoos provide. To understand the key factors contributing to the decline in venomous snake numbers, 57 staff members across 35 different BIAZA-accredited zoos were surveyed. Results from the survey identified that a perceived increased risk of harm, increasingly stringent health and safety regulations, and increased husbandry requirements were all key contributing factors to why venomous snake numbers at zoos are in decline.

6.
Physiology (Bethesda) ; 37(6): 323-348, 2022 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-35820180

RESUMEN

Granzymes are serine proteases previously believed to play exclusive and somewhat redundant roles in lymphocyte-mediated target cell death. However, recent studies have challenged this paradigm. Distinct substrate profiles and functions have since emerged for each granzyme while their dysregulated proteolytic activities have been linked to diverse pathologies.


Asunto(s)
Granzimas , Humanos , Granzimas/metabolismo , Cicatrización de Heridas , Serina Proteasas , Inflamación
7.
Lab Invest ; 103(6): 100123, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36849037

RESUMEN

Age-related macular degeneration (AMD) is a leading cause of irreversible central vision loss in the elderly. The pathology of neovascular age-related macular degeneration (nAMD), also known as wet AMD, is associated with an abnormal blood vessel growth in the eye and involves an imbalance of proangiogenic and antiangiogenic factors. Thrombospondin (TSP)-1 and TSP-2 are endogenous matricellular proteins that inhibit angiogenesis. TSP-1 is significantly diminished in eyes with AMD, although the mechanisms involved in its reduction are unknown. Granzyme B (GzmB) is a serine protease with an increased extracellular activity in the outer retina and choroid of human eyes with nAMD-related choroidal neovascularization (CNV). This study investigated whether TSP-1 and TSP-2 are GzmB substrates using in silico and cell-free cleavage assays and explored the relationship between GzmB and TSP-1 in human eyes with nAMD-related CNV and the effect of GzmB on TSP-1 in retinal pigment epithelial culture and an explant choroid sprouting assay (CSA). In this study, TSP-1 and TSP-2 were identified as GzmB substrates. Cell-free cleavage assays substantiated the GzmB proteolysis of TSP-1 and TSP-2 by showing dose-dependent and time-dependent cleavage products. TSP-1 and TSP-2 proteolysis were hindered by the inhibition of GzmB. In the retinal pigment epithelium and choroid of human eyes with CNV, we observed a significant inverse correlation between TSP-1 and GzmB, as indicated by lower TSP-1 and higher GzmB immunoreactivity. In CSA, the vascular sprouting area increased significantly with GzmB treatment and reduced significantly with TSP-1 treatment. Western blot showed significantly reduced expression of TSP-1 in GzmB-treated retinal pigment epithelial cell culture and CSA supernatant compared with that in controls. Together, our findings suggest that the proteolysis of antiangiogenic factors such as TSP-1 by extracellular GzmB might represent a mechanism through which GzmB may contribute to nAMD-related CNV. Future studies are needed to investigate whether pharmacologic inhibition of extracellular GzmB can mitigate nAMD-related CNV by preserving intact TSP-1.


Asunto(s)
Neovascularización Coroidal , Degeneración Macular , Humanos , Anciano , Trombospondina 1/metabolismo , Granzimas/metabolismo , Proteolisis , Degeneración Macular/complicaciones , Degeneración Macular/metabolismo , Degeneración Macular/patología , Neovascularización Coroidal/tratamiento farmacológico , Neovascularización Coroidal/etiología , Neovascularización Coroidal/metabolismo
8.
Mol Psychiatry ; 27(9): 3864-3874, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35595980

RESUMEN

Nicotine intake, whether through tobacco smoking or e-cigarettes, remains a global health concern. An emerging preclinical literature indicates that parental nicotine exposure produces behavioral, physiological, and molecular changes in subsequent generations. However, the heritable effects of voluntary parental nicotine taking are unknown. Here, we show increased acquisition of nicotine taking in male and female offspring of sires that self-administered nicotine. In contrast, self-administration of sucrose and cocaine were unaltered in male and female offspring suggesting that the intergenerational effects of paternal nicotine taking may be reinforcer specific. Further characterization revealed memory deficits and increased anxiety-like behaviors in drug-naive male, but not female, offspring of nicotine-experienced sires. Using an unbiased, genome-wide approach, we discovered that these phenotypes were associated with decreased expression of Satb2, a transcription factor known to play important roles in synaptic plasticity and memory formation, in the hippocampus of nicotine-sired male offspring. This effect was sex-specific as no changes in Satb2 expression were found in nicotine-sired female offspring. Finally, increasing Satb2 levels in the hippocampus prevented the escalation of nicotine intake and rescued the memory deficits associated with paternal nicotine taking in male offspring. Collectively, these findings indicate that paternal nicotine taking produces heritable sex-specific molecular changes that promote addiction-like phenotypes and memory impairments in male offspring.


Asunto(s)
Proteínas de Unión a la Región de Fijación a la Matriz , Nicotina , Exposición Paterna , Factores de Transcripción , Femenino , Masculino , Hipocampo , Proteínas de Unión a la Región de Fijación a la Matriz/genética , Trastornos de la Memoria , Nicotina/efectos adversos , Exposición Paterna/efectos adversos , Fenotipo , Factores de Transcripción/genética , Animales
9.
Br J Dermatol ; 189(3): 279-291, 2023 08 24.
Artículo en Inglés | MEDLINE | ID: mdl-36652225

RESUMEN

BACKGROUND: Granzyme K (GzmK) is a serine protease with minimal presence in healthy tissues while abundant in inflamed tissues. Initially thought to play an exclusive role in immune-mediated cell death, extracellular GzmK can also promote inflammation. OBJECTIVES: To evaluate the role of GzmK in the pathogenesis of atopic dermatitis (AD), the most common inflammatory skin disease. METHODS: A panel of human AD and control samples was analysed to determine if GzmK is elevated. Next, to determine a pathological role for GzmK in AD-like skin inflammation, oxazolone-induced dermatitis was induced in GzmK-/- and wild-type (WT) mice. RESULTS: In human lesional AD samples, there was an increase in the number of GzmK+ cells compared with healthy controls. GzmK-/- mice exhibited reduced overall disease severity characterized by reductions in scaling, erosions and erythema. Surprisingly, the presence of GzmK did not notably increase the overall pro-inflammatory response or epidermal barrier permeability in WT mice; rather, GzmK impaired angiogenesis, increased microvascular damage and microhaemorrhage. Mechanistically, GzmK contributed to vessel damage through cleavage of syndecan-1, a key structural component of the glycocalyx, which coats the luminal surface of vascular endothelia. CONCLUSIONS: GzmK may provide a potential therapeutic target for skin conditions associated with persistent inflammation, vasculitis and pathological angiogenesis.


Asunto(s)
Dermatitis Atópica , Granzimas , Animales , Humanos , Ratones , Dermatitis Atópica/patología , Epidermis/metabolismo , Granzimas/metabolismo , Inflamación , Piel/patología
10.
Development ; 146(9)2019 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-30967426

RESUMEN

Establishing apical-basal epithelial cell polarity is fundamental for mammary gland duct morphogenesis during mammalian development. While the focal adhesion adapter protein paxillin is a well-characterized regulator of mesenchymal cell adhesion signaling, F-actin cytoskeleton remodeling and single cell migration, its role in epithelial tissue organization and mammary gland morphogenesis in vivo has not been investigated. Here, using a newly developed paxillin conditional knockout mouse model with targeted ablation in the mammary epithelium, in combination with ex vivo three-dimensional organoid and acini cultures, we identify new roles for paxillin in the establishment of apical-basal epithelial cell polarity and lumen formation, as well as mammary gland duct diameter and branching. Paxillin is shown to be required for the integrity and apical positioning of the Golgi network, Par complex and the Rab11/MyoVb trafficking machinery. Paxillin depletion also resulted in reduced levels of apical acetylated microtubules, and rescue experiments with the HDAC6 inhibitor tubacin highlight the central role for paxillin-dependent regulation of HDAC6 activity and associated microtubule acetylation in controlling epithelial cell apical-basal polarity and tissue branching morphogenesis.


Asunto(s)
Polaridad Celular/fisiología , Células Epiteliales/citología , Glándulas Mamarias Animales/citología , Glándulas Mamarias Animales/metabolismo , Paxillin/metabolismo , Animales , Movimiento Celular/genética , Movimiento Celular/fisiología , Polaridad Celular/genética , Células Epiteliales/metabolismo , Matriz Extracelular/metabolismo , Ratones , Microtúbulos/metabolismo , Morfogénesis/genética , Morfogénesis/fisiología , Paxillin/genética , Transducción de Señal/genética , Transducción de Señal/fisiología
11.
Lancet Oncol ; 22(7): 959-969, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-34118197

RESUMEN

BACKGROUND: Oncogenic alterations in RET have been identified in multiple tumour types, including 1-2% of non-small-cell lung cancers (NSCLCs). We aimed to assess the safety, tolerability, and antitumour activity of pralsetinib, a highly potent, oral, selective RET inhibitor, in patients with RET fusion-positive NSCLC. METHODS: ARROW is a multi-cohort, open-label, phase 1/2 study done at 71 sites (community and academic cancer centres) in 13 countries (Belgium, China, France, Germany, Hong Kong, Italy, Netherlands, Singapore, South Korea, Spain, Taiwan, the UK, and the USA). Patients aged 18 years or older with locally advanced or metastatic solid tumours, including RET fusion-positive NSCLC, and an Eastern Cooperative Oncology Group performance status of 0-2 (later limited to 0-1 in a protocol amendment) were enrolled. In phase 2, patients received 400 mg once-daily oral pralsetinib, and could continue treatment until disease progression, intolerance, withdrawal of consent, or investigator decision. Phase 2 primary endpoints were overall response rate (according to Response Evaluation Criteria in Solid Tumours version 1·1 and assessed by blinded independent central review) and safety. Tumour response was assessed in patients with RET fusion-positive NSCLC and centrally adjudicated baseline measurable disease who had received platinum-based chemotherapy or were treatment-naive because they were ineligible for standard therapy. This ongoing study is registered with ClinicalTrials.gov, NCT03037385, and enrolment of patients with treatment-naive RET fusion-positive NSCLC was ongoing at the time of this interim analysis. FINDINGS: Of 233 patients with RET fusion-positive NSCLC enrolled between March 17, 2017, and May 22, 2020 (data cutoff), 92 with previous platinum-based chemotherapy and 29 who were treatment-naive received pralsetinib before July 11, 2019 (efficacy enrolment cutoff); 87 previously treated patients and 27 treatment-naive patients had centrally adjudicated baseline measurable disease. Overall responses were recorded in 53 (61%; 95% CI 50-71) of 87 patients with previous platinum-based chemotherapy, including five (6%) patients with a complete response; and 19 (70%; 50-86) of 27 treatment-naive patients, including three (11%) with a complete response. In 233 patients with RET fusion-positive NSCLC, common grade 3 or worse treatment-related adverse events were neutropenia (43 patients [18%]), hypertension (26 [11%]), and anaemia (24 [10%]); there were no treatment-related deaths in this population. INTERPRETATION: Pralsetinib is a new, well-tolerated, promising, once-daily oral treatment option for patients with RET fusion-positive NSCLC. FUNDING: Blueprint Medicines.


Asunto(s)
Antineoplásicos/uso terapéutico , Biomarcadores de Tumor/genética , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Fusión Génica , Neoplasias Pulmonares/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/uso terapéutico , Proteínas Proto-Oncogénicas c-ret/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-ret/genética , Pirazoles/uso terapéutico , Piridinas/uso terapéutico , Pirimidinas/uso terapéutico , Anciano , Antineoplásicos/efectos adversos , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/patología , Femenino , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Inhibidores de Proteínas Quinasas/efectos adversos , Pirazoles/efectos adversos , Piridinas/efectos adversos , Pirimidinas/efectos adversos , Factores de Tiempo , Resultado del Tratamiento
12.
Eur J Neurosci ; 53(5): 1592-1604, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33098709

RESUMEN

Studies using transcranial direct current stimulation (tDCS) typically incorporate a fade-in, short-stimulation, fade-out sham (placebo) protocol, which is assumed to be indistinct from a 10-30 min active protocol on the scalp. However, many studies report that participants can dissociate active stimulation from sham, even during low-intensity 1 mA currents. We recently identified differences in the perception of an active (10 min of 1 mA) and a sham (20 s of 1 mA) protocol that lasted for 5 min after the cessation of sham. In the present study we assessed whether delivery of a higher-intensity 2 mA current would exacerbate these differences. Two protocols were delivered to 32 adults in a double-blinded, within-subjects design (active: 10 min of 2 mA, and sham: 20 s of 2 mA), with the anode over the left primary motor cortex and the cathode on the right forehead. Participants were asked "Is the stimulation on?" and "How sure are you?" at 30 s intervals during and after stimulation. The differences between active and sham were more consistent and sustained during 2 mA than during 1 mA. We then quantified how well participants were able to track the presence and absence of stimulation (i.e. their sensitivity) during the experiment using cross-correlations. Current strength was a good classifier of sensitivity during active tDCS, but exhibited only moderate specificity during sham. The accuracy of the end-of-study guess was no better than chance at predicting sensitivity. Our results indicate that the traditional end-of-study guess poorly reflects the sensitivity of participants to stimulation, and may not be a valid method of assessing sham blinding.


Asunto(s)
Corteza Motora , Estimulación Transcraneal de Corriente Directa , Adulto , Método Doble Ciego , Electrodos , Humanos , Cuero Cabelludo
13.
Phys Rev Lett ; 126(21): 210601, 2021 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-34114830

RESUMEN

Motivated by recent observations of ergodicity breaking due to Hilbert space fragmentation in 1D Fermi-Hubbard chains with a tilted potential [Scherg et al., arXiv:2010.12965], we show that the same system also hosts quantum many-body scars in a regime U≈Δ≫J at electronic filling factor ν=1. We numerically demonstrate that the scarring phenomenology in this model is similar to other known realizations such as Rydberg atom chains, including persistent dynamical revivals and ergodicity-breaking many-body eigenstates. At the same time, we show that the mechanism of scarring in the Fermi-Hubbard model is different from other examples in the literature: the scars originate from a subgraph, representing a free spin-1 paramagnet, which is weakly connected to the rest of the Hamiltonian's adjacency graph. Our work demonstrates that correlated fermions in tilted optical lattices provide a platform for understanding the interplay of many-body scarring and other forms of ergodicity breaking, such as localization and Hilbert space fragmentation.

14.
Sensors (Basel) ; 21(13)2021 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-34206373

RESUMEN

Cyber-physical systems such as satellite telecommunications networks generate vast amounts of data and currently, very crude data processing is used to extract salient information. Only a small subset of data is used reactively by operators for troubleshooting and finding problems. Sometimes, problematic events in the network may go undetected for weeks before they are reported. This becomes even more challenging as the size of the network grows due to the continuous proliferation of Internet of Things type devices. To overcome these challenges, this research proposes a knowledge-based cognitive architecture supported by machine learning algorithms for monitoring satellite network traffic. The architecture is capable of supporting and augmenting infrastructure engineers in finding and understanding the causes of faults in network through the fusion of the results of machine learning models and rules derived from human domain experience. The system is characterised by (1) the flexibility to add new or extend existing machine learning algorithms to meet the user needs, (2) an enhanced pattern recognition and prediction through the support of machine learning algorithms and the expert knowledge on satellite infrastructure, (3) the ability to adapt to changing conditions of the satellite network, and (4) the ability to augment satellite engineers through interpretable results. An industrial real-life satellite case study is provided to demonstrate how the architecture could be used. A single blind experimental methodology was used to validate the results generated by our approach.


Asunto(s)
Algoritmos , Aprendizaje Automático , Cognición , Humanos , Bases del Conocimiento , Método Simple Ciego
15.
Nano Lett ; 20(4): 2209-2218, 2020 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-32058724

RESUMEN

Graphene oxide (GO) membranes have great potential for separation applications due to their low-friction water permeation combined with unique molecular sieving ability. However, the practical use of deposited GO membranes is limited by the inferior mechanical robustness of the membrane composite structure derived from conventional deposition methods. Here, we report a nanostructured GO membrane that possesses great permeability and mechanical robustness. This composite membrane consists of an ultrathin selective GO nanofilm (as low as 32 nm thick) and a postsynthesized macroporous support layer that exhibits excellent stability in water and under practical permeability testing. By utilizing thin-film lift off (T-FLO) to fabricate membranes with precise optimizations in both selective and support layers, unprecedented water permeability (47 L·m-2·hr-1·bar-1) and high retention (>98% of solutes with hydrated radii larger than 4.9 Å) were obtained.

16.
Genes Dev ; 27(23): 2576-89, 2013 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-24298057

RESUMEN

B-class ephrins, ligands for EphB receptor tyrosine kinases, are critical regulators of growth and patterning processes in many organs and species. In the endothelium of the developing vasculature, ephrin-B2 controls endothelial sprouting and proliferation, which has been linked to vascular endothelial growth factor (VEGF) receptor endocytosis and signaling. Ephrin-B2 also has essential roles in supporting mural cells (namely, pericytes and vascular smooth muscle cells [VSMCs]), but the underlying mechanism is not understood. Here, we show that ephrin-B2 controls platelet-derived growth factor receptor ß (PDGFRß) distribution in the VSMC plasma membrane, endocytosis, and signaling in a fashion that is highly distinct from its role in the endothelium. Absence of ephrin-B2 in cultured VSMCs led to the redistribution of PDGFRß from caveolin-positive to clathrin-associated membrane fractions, enhanced PDGF-B-induced PDGFRß internalization, and augmented downstream mitogen-activated protein (MAP) kinase and c-Jun N-terminal kinase (JNK) activation but impaired Tiam1-Rac1 signaling and proliferation. Accordingly, mutant mice lacking ephrin-B2 expression in vascular smooth muscle developed vessel wall defects and aortic aneurysms, which were associated with impaired Tiam1 expression and excessive activation of MAP kinase and JNK. Our results establish that ephrin-B2 is an important regulator of PDGFRß endocytosis and thereby acts as a molecular switch controlling the downstream signaling activity of this receptor in mural cells.


Asunto(s)
Efrina-B2/metabolismo , Receptor beta de Factor de Crecimiento Derivado de Plaquetas/metabolismo , Transducción de Señal , Animales , Membrana Celular/metabolismo , Células Cultivadas , Efrina-B2/genética , Femenino , Masculino , Ratones , Mutación , Miocitos del Músculo Liso/patología , Transporte de Proteínas
17.
Development ; 144(21): 4002-4014, 2017 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-28935710

RESUMEN

Paxillin and Hic-5 are homologous focal adhesion adaptor proteins that coordinate cytoskeletal rearrangements in response to integrin signaling, but their role(s) in cortical development are unknown. Here, we find that Hic-5-deficient mice are postnatal viable with normal cortical layering. Mice with a neural-specific deletion of paxillin are also postnatal viable, but show evidence of a cortical neuron migration delay that is evident pre- and perinatally, but is not detected at postnatal day 35 (P35). This phenotype is not modified by Hic-5 deficiency (double knockout). Specific deletion of paxillin in postmitotic neurons using Nex-Cre-mediated recombination as well as in utero electroporation of a Cre-expression construct identified a cell-autonomous requirement for paxillin in migrating neurons. Paxillin-deficient neurons have shorter leading processes that exhibited multiple swellings in comparison with control. Multiphoton imaging revealed that paxillin-deficient neurons migrate ∼30% slower than control neurons. This phenotype is similar to that produced by deletion of focal adhesion kinase (FAK), a signaling partner of paxillin, and suggests that paxillin and FAK function cell-autonomously to control migrating neuron morphology and speed during cortical development.


Asunto(s)
Movimiento Celular , Corteza Cerebral/embriología , Corteza Cerebral/metabolismo , Adhesiones Focales/metabolismo , Neuronas/citología , Neuronas/metabolismo , Paxillin/metabolismo , Alelos , Animales , Movimiento Celular/genética , Forma de la Célula , Proteínas del Citoesqueleto/genética , Proteínas del Citoesqueleto/metabolismo , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Eliminación de Gen , Regulación del Desarrollo de la Expresión Génica , Integrasas/metabolismo , Proteínas con Dominio LIM/genética , Proteínas con Dominio LIM/metabolismo , Ratones Noqueados , Células-Madre Neurales/metabolismo , Especificidad de Órganos , Paxillin/deficiencia , Paxillin/genética
18.
Cancer ; 125(7): 1113-1123, 2019 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-30690710

RESUMEN

BACKGROUND: Glembatumumab vedotin is an antibody-drug conjugate that produced preliminary clinical activity against advanced melanoma in a phase 1 dose-escalation trial. The objective of the current study was to investigate further the antitumor activity of glembatumumab vedotin at the recommended phase 2 dose in heavily pretreated patients with melanoma. METHODS: This single-arm, phase 2 study enrolled patients with stage IV melanoma who were refractory to checkpoint inhibition and to B-raf proto-oncogene, serine/threonine kinase (BRAF)/mitogen-activated protein kinase kinase (MEK) inhibition (in the presence of a BRAF valine mutation at codon 600). Patients received 1.9 mg/kg glembatumumab vedotin intravenously every 3 weeks until they developed disease progression or intolerance. The primary endpoint was objective response rate (ORR), which was determined according to Response Evaluation Criteria in Solid Tumors, version 1.1. Secondary endpoints included progression-free survival (PFS), duration of response, overall survival (OS), safety, and clinical efficacy versus tumor glycoprotein NMB (gpNMB) expression. Tumor expression of gpNMB was assessed using immunohistochemistry. RESULTS: In total, 62 patients received treatment. The ORR was 11% and the median response duration was 6.0 months (95% confidence interval [CI], 4.1 months to not reached). The median PFS was 4.4 months (95% CI, 2.6-5.5 months), and the median OS was 9.0 months (95% CI, 6.1-11.7 months). For patients who developed rash during the first cycle versus those who did not, the ORR was 21% versus 7%, respectively, and there was an overall improvement in PFS (hazard ratio, 0.43; P = .013) and OS (hazard ratio, 0.43; P = .017). The most frequent adverse events were alopecia, neuropathy, rash, fatigue, and neutropenia. With one exception, all evaluable tumors were positive for gpNMB, and 46 of 59 tumors (76%) had 100% gpNMB-positive epithelial cells. CONCLUSIONS: Glembatumumab vedotin had modest activity and an acceptable safety profile in patients with advanced melanoma who were refractory to checkpoint inhibitors and MEK/BRAF inhibition. Treatment-related rash may be associated with response.


Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Antineoplásicos Inmunológicos/uso terapéutico , Inmunoconjugados/uso terapéutico , Melanoma/tratamiento farmacológico , Neoplasias Cutáneas/tratamiento farmacológico , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Melanoma/metabolismo , Melanoma/patología , Glicoproteínas de Membrana/metabolismo , Persona de Mediana Edad , Estadificación de Neoplasias , Supervivencia sin Progresión , Modelos de Riesgos Proporcionales , Proto-Oncogenes Mas , Neoplasias Cutáneas/metabolismo , Neoplasias Cutáneas/patología , Resultado del Tratamiento
19.
Phys Rev Lett ; 122(22): 220603, 2019 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-31283292

RESUMEN

Motivated by recent experimental observations of coherent many-body revivals in a constrained Rydberg atom chain, we construct a weak quasilocal deformation of the Rydberg-blockaded Hamiltonian, which makes the revivals virtually perfect. Our analysis suggests the existence of an underlying nonintegrable Hamiltonian which supports an emergent SU(2)-spin dynamics within a small subspace of the many-body Hilbert space. We show that such perfect dynamics necessitates the existence of atypical, nonergodic energy eigenstates-quantum many-body scars. Furthermore, using these insights, we construct a toy model that hosts exact quantum many-body scars, providing an intuitive explanation of their origin. Our results offer specific routes to enhancing coherent many-body revivals and provide a step toward establishing the stability of quantum many-body scars in the thermodynamic limit.

20.
Pract Neurol ; 19(1): 72-74, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30282763

RESUMEN

Compressive lesions of the spinal cord usually cause a syndrome of upper motor neurone weakness, spasticity and sensory loss below the level of the lesion. It has long been recognised that compressive cervical cord lesions may present as isolated lower motor neurone weakness of the upper limbs, a syndrome termed cervical spondylotic amyotrophy. We describe two patients presenting with isolated lower motor neurone weakness of the lower limbs in association with a compressive cord lesion at T11/12, a condition we have termed thoracic spondylotic amyotrophy.


Asunto(s)
Extremidad Inferior , Neuronas Motoras/patología , Debilidad Muscular/etiología , Compresión de la Médula Espinal/complicaciones , Espondilosis/complicaciones , Humanos , Masculino , Persona de Mediana Edad , Síndrome , Vértebras Torácicas
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