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1.
Mol Ther ; 2024 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-38946142

RESUMO

The chimeric antigen receptor (CAR) derived from the CD30 specific murine antibody, HRS-3, has produced promising clinical efficacy with a favorable safety profile in the treatment of relapsed or refractory CD30-positive lymphomas. However, persistence of the autologous CAR-T cells was brief, and many patients relapsed a year after treatment. The lack of persistence may be attributed to the use of a wild-type immunoglobulin (Ig)G1 spacer that can associate with Fc receptors. We first identified the cysteine-rich domain (CRD) 5 of CD30 as the primary binding epitope of HRS-3 and armed with this insight, attempted to improve the HRS-3 CAR functionality with a panel of novel spacer designs. We demonstrate that HRS-3 CARs with OX40 and 4-1BB derived spacers exhibited similar anti-tumor efficacy, circumvented interactions with Fc receptors, and secreted lower levels of cytokines in vitro than a CAR employing the IgG1 spacer. Humanization of the HRS-3 scFv coupled with the 4-1BB spacer preserved potent on-target, on-tumor efficacy, and on-target, off-tumor safety. In a lymphoma mouse model of high tumor burden, T cells expressing humanized HRS-3 CD30.CARs with the 4-1BB spacer potently killed tumors with low levels of circulating inflammatory cytokines, providing a promising candidate for future clinical development in the treatment of CD30-positive malignancies.

2.
Genes Dev ; 31(1): 12-17, 2017 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-28115466

RESUMO

Global DNA demethylation is a hallmark of embryonic epigenetic reprogramming. However, embryos engage noncanonical DNA methylation maintenance mechanisms to ensure inheritance of exceptional epigenetic germline features to the soma. Besides the paradigmatic genomic imprints, these exceptions remain ill-defined, and the mechanisms ensuring demethylation resistance in the light of global reprogramming remain poorly understood. Here we show that the Y-linked gene Rbmy1a1 is highly methylated in mature sperm and resists DNA demethylation post-fertilization. Aberrant hypomethylation of the Rbmy1a1 promoter results in its ectopic activation, causing male-specific peri-implantation lethality. Rbmy1a1 is a novel target of the TRIM28 complex, which is required to protect its repressive epigenetic state during embryonic epigenetic reprogramming.


Assuntos
Metilação de DNA/genética , Desenvolvimento Embrionário/genética , Epigênese Genética/genética , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas de Ligação a RNA/metabolismo , Proteínas Repressoras/genética , Animais , Células Cultivadas , Reprogramação Celular/genética , Implantação do Embrião/genética , Embrião de Mamíferos , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Impressão Genômica/genética , Masculino , Mutação , Regiões Promotoras Genéticas/genética , Proteínas de Ligação a RNA/genética , Espermatozoides/metabolismo , Proteína 28 com Motivo Tripartido
3.
Small ; 19(2): e2204520, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36354178

RESUMO

The discovery of more efficient and stable catalysts for oxygen evolution reaction (OER) is vital in improving the efficiency of renewable energy generation devices. Given the large numbers of possible binary and ternary metal oxide OER catalysts, high-throughput methods are necessary to accelerate the rate of discovery. Herein, Mn-based spinel oxide, Fe10 Co40 Mn50 O, is identified for the first time using high-throughput methods demonstrating remarkable catalytic activity (overpotential of 310 mV on fluorine-doped tin oxide (FTO) substrate and 237 mV on Ni foam at 10 mA cm-2 ). Using a combination of soft X-ray absorption spectroscopy and electrochemical measurements, the high catalytic activity is attributed to 1) the formation of multiple active sites in different geometric sites, tetrahedral and octahedral sites; and 2) the formation of active oxyhydroxide phase due to the strong interaction of Co2+ and Fe3+ . Structural and surface characterizations after OER show preservation of Fe10 Co40 Mn50 O surface structure highlighting its durability against irreversible redox damage on the catalytic surface. This work demonstrates the use of a high-throughput approach for the rapid identification of a new catalyst, provides a deeper understanding of catalyst design, and addresses the urgent need for a better and stable catalyst to target greener fuel.


Assuntos
Ensaios de Triagem em Larga Escala , Óxidos , Domínio Catalítico , Oxigênio
4.
J Immunol ; 206(2): 323-328, 2021 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-33288542

RESUMO

The NOX2 NADPH oxidase (NOX2) produces reactive oxygen species to kill phagosome-confined bacteria. However, we previously showed that Listeria monocytogenes is able to avoid the NOX2 activity in phagosomes and escape to the cytosol. Thus, despite the established role of NOX2 limiting L. monocytogenes infection in mice, the underlying mechanisms of this antibacterial activity remain unclear. In this article, we report that NOX2 controls systemic L. monocytogenes spread through modulation of the type I IFN response, which is known to be exploited by L. monocytogenes during infection. NOX2 deficiency results in increased expression of IFN-stimulated genes in response to type I IFN and leads to 1) promotion of cell-to-cell spread by L. monocytogenes, 2) defective leukocyte recruitment to infection foci, and 3) production of anti-inflammatory effectors IL-10 and thioredoxin 1. Our findings report a novel antimicrobial role for NOX2 through modulation of type I IFN responses to control bacterial dissemination.


Assuntos
Inflamação/imunologia , Interferon Tipo I/metabolismo , Leucócitos/imunologia , Listeria monocytogenes/fisiologia , Listeriose/imunologia , Macrófagos/metabolismo , NADPH Oxidase 2/metabolismo , Animais , Movimento Celular , Células Cultivadas , Interleucina-10/metabolismo , Listeriose/transmissão , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , NADPH Oxidase 2/genética , Tiorredoxinas
5.
Immun Ageing ; 20(1): 49, 2023 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-37752597

RESUMO

BACKGROUND: Preclinical models are often used for cancer studies and evaluation of novel therapeutics. The relevance of these models has vastly improved with mice bearing a human immune system, especially in the context of immunotherapy. Nonetheless, cancer is an age-related disease, and studies often overlook the effects of aging. Here we have established a humanized mouse model of human immune aging to investigate the role of this phenomenon on liver tumor dynamics. METHODS: Multiple organs and tissues (blood, thymus, lung, liver, spleen and bone marrow) were harvested from NOD-scid IL2rγ-/- (NIKO) mice reconstituted with human immune cells, over a period of 60 weeks post-birth, for immune profiling. Young and aging immune cells were compared for transcriptomic changes and functional differences. Effect of immune aging was investigated in a liver cancer humanized mouse model. RESULTS: Focusing on the T cell population, which is central to cancer immunosurveillance and immunotherapy, we showed that the proportion of naïve T cells declined while memory subsets and senescent-like cells increased with age. RNA-sequencing revealed that downregulated genes were related to immune responses and processes, and this was corroborated by reduced cytokine production in aging T cells. Finally, we showed faster liver tumor growth in aging than younger humanized mice, which could be attributed to specific pathways of aging T cell exhaustion. CONCLUSION: Our work improves on existing humanized (immune) mouse model and highlights the importance of considering immune aging in liver cancer modeling.

6.
Eur Spine J ; 32(7): 2493-2502, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37191676

RESUMO

PURPOSE: Allogeneic blood transfusion (ABT) is current standard of blood replenishment despite known complications. Salvaged blood transfusion (SBT) addresses majority of such complications. Surgeons remain reluctant to employ SBT in metastatic spine tumour surgery (MSTS), despite ample laboratory evidence. This prompted us to conduct a prospective clinical study to ascertain safety of intraoperative cell salvage (IOCS), in MSTS. METHODS: Our prospective study included 73 patients who underwent MSTS from 2014 to 2017. Demographics, tumour histology and burden, clinical findings, modified Tokuhashi score, operative and blood transfusion (BT) details were recorded. Patients were divided based on BT type: no blood transfusion (NBT) and SBT/ABT. Primary outcomes assessed were overall survival (OS), and tumour progression was evaluated using RECIST (v1.1) employing follow-up radiological investigations at 6, 12 and 24 months, classifying patients with non-progressive and progressive disease. RESULTS: Seventy-three patients [39:34(M/F)] had mean age of 61 years. Overall median follow-up and survival were 26 and 12 months, respectively. All three groups were comparable for demographics and tumour characteristics. Overall median blood loss was 500 mL, and BT was 1000 mL. Twenty-six (35.6%) patients received SBT, 27 (37.0%) ABT and 20 (27.4%) NBT. Females had lower OS and higher risk of tumour progression. SBT had better OS and reduced risk of tumour progression than ABT group. Total blood loss was not associated with tumour progression. Infective complications other than SSI were significantly (p = 0.027) higher in ABT than NBT/SBT groups. CONCLUSIONS: Patients of SBT had OS and tumour progression better than ABT/NBT groups. This is the first prospective study to report of SBT in comparison with control groups in MSTS.


Assuntos
Transfusão de Sangue Autóloga , Neoplasias da Coluna Vertebral , Feminino , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos , Neoplasias da Coluna Vertebral/diagnóstico por imagem , Neoplasias da Coluna Vertebral/cirurgia , Neoplasias da Coluna Vertebral/patologia , Transfusão de Sangue
7.
Ann Surg Oncol ; 28(5): 2474-2482, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33393052

RESUMO

BACKGROUND: Outcomes commonly used to ascertain success of metastatic spine tumour surgery (MSTS) are 30-day complications/mortality and overall/disease-free survival. We believe a new, effective outcome indicator after MSTS would be the absence of unplanned hospital readmission (UHR) after index discharge. We introduce the concept of readmission-free survival (ReAFS), defined as 'the time duration between hospital discharge after index operation and first UHR or death'. The aim of this study is to identify factors influencing ReAFS in MSTS patients. PATIENTS AND METHODS: We retrospectively analysed 266 consecutive patients who underwent MSTS between 2005 and 2016. Demographics, oncological characteristics, procedural, preoperative and postoperative details were collected. ReAFS of patients within 2 years or until death was reviewed. Perioperative factors predictive of reduced ReAFS were evaluated using multivariate regression analysis. RESULTS: Of 266 patients, 230 met criteria for analysis. A total of 201 had UHR, whilst 1 in 8 (29/230) had no UHR. Multivariate analysis revealed that haemoglobin ≥ 12 g/dL, ECOG score of ≤ 2, primary prostate, breast and haematological cancers, comorbidities ≤ 3, absence of preoperative radiotherapy and shorter postoperative length of stay significantly prolonged the time to first UHR. CONCLUSIONS: Readmission-free survival is a novel concept in MSTS, which relies on patients' general condition, appropriateness of interventional procedures and underlying disease burden. Additionally, it may indicate the successful combination of a multi-disciplinary treatment approach. This information will allow oncologists and surgeons to identify patients who may benefit from increased surveillance following discharge to increase ReAFS. We envisage that ReAFS is a concept that can be extended to other surgical oncological fields.


Assuntos
Neoplasias , Complicações Pós-Operatórias , Humanos , Tempo de Internação , Masculino , Readmissão do Paciente , Estudos Retrospectivos , Fatores de Risco , Coluna Vertebral , Análise de Sobrevida
8.
Eur Spine J ; 30(10): 2887-2895, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33459874

RESUMO

PURPOSE: The aim of this study was to investigate rates, causes, and risk factors of unplanned hospital readmissions (UHR) within 30 days, 90 days, 1 year and 2 years after metastatic spine tumour surgery (MSTS) to augment multi-disciplinary treatment planning and improve patient education. METHODS: We retrospectively reviewed 272-patients who underwent MSTS between 2005 and 2016. Hospital records were utilised to obtain demographics, oncological, procedural details, and postoperative outcomes. All UHR within 2 years were reviewed. Primary outcomes were rates, causes, and risk factors of UHR. Risk factors for UHR were evaluated utilising multivariate logistic regression analysis. RESULTS: Thirty-day, 90 day, 1 year, and 2 year UHR-rates after MSTS were 17.2%, 31.1%, 46.2%, and 52.7%, respectively. Lung cancer primaries had the highest UHR-events (24.7%) whilst renal/thyroid displayed the least (6.6%). Disease-related causes (16.2%) were the most common reason for readmissions across all timeframes, followed by respiratory (13.7%) and progression of metastatic spine disease (12.7%). Urological conditions accounted for majority of readmissions within 30-days; disease-related causes, symptomatic spinal metastases, and respiratory conditions represented the most common causes at 30-90 days, 90 days-1 year, and 1-2 years, respectively. An ECOG >1 (p = 0.057), CCI >7 (p = 0.01), and primary lung tumour (p = 0.02) significantly increased UHR-risk on multivariate analysis. CONCLUSION: Seventy-four percent of patients had at least one UHR within 2 years of MSTS and majority were secondary to disease-related causes. Majority of first UHR occurred between 30 and 90 days post-surgery. Local disease progression and overall disease progression account for the highest UHR-events at 90 days-1 year and 1-2 year timeframes, respectively. We define UHR in specific timeframes, thus enabling better surveillance and reducing unnecessary morbidity.


Assuntos
Neoplasias , Readmissão do Paciente , Humanos , Estudos Retrospectivos , Coluna Vertebral , Fatores de Tempo
9.
J Biol Chem ; 294(44): 16172-16185, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31515271

RESUMO

Connections between deficient autophagy and insulin resistance have emerged, however, the mechanism through which reduced autophagy impairs insulin-signaling remains unknown. We examined mouse embryonic fibroblasts lacking Atg16l1 (ATG16L1 KO mouse embryonic fibroblasts (MEFs)), an essential autophagy gene, and observed deficient insulin and insulin-like growth factor-1 signaling. ATG16L1 KO MEFs displayed reduced protein content of insulin receptor substrate-1 (IRS1), pivotal to insulin signaling, whereas IRS1myc overexpression recovered downstream insulin signaling. Endogenous IRS1 protein content and insulin signaling were restored in ATG16L1 KO mouse embryonic fibroblasts (MEF) upon proteasome inhibition. Through proximity-dependent biotin identification (BioID) and co-immunoprecipitation, we found that Kelch-like proteins KLHL9 and KLHL13, which together form an E3 ubiquitin (Ub) ligase complex with cullin 3 (CUL3), are novel IRS1 interactors. Expression of Klhl9 and Klhl13 was elevated in ATG16L1 KO MEFs and siRNA-mediated knockdown of Klhl9, Klhl13, or Cul3 recovered IRS1 expression. Moreover, Klhl13 and Cul3 knockdown increased insulin signaling. Notably, adipose tissue of high-fat fed mice displayed lower Atg16l1 mRNA expression and IRS1 protein content, and adipose tissue KLHL13 and CUL3 expression positively correlated to body mass index in humans. We propose that ATG16L1 deficiency evokes insulin resistance through induction of Klhl9 and Klhl13, which, in complex with Cul3, promote proteasomal IRS1 degradation.


Assuntos
Proteínas Relacionadas à Autofagia/deficiência , Proteínas Substratos do Receptor de Insulina/metabolismo , Resistência à Insulina , Animais , Autofagia/fisiologia , Proteínas Relacionadas à Autofagia/genética , Proteínas Relacionadas à Autofagia/metabolismo , Proteínas Culina/metabolismo , Fibroblastos/metabolismo , Genes Reguladores , Células HEK293 , Humanos , Insulina/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteínas/metabolismo , Transdução de Sinais , Complexos Ubiquitina-Proteína Ligase/metabolismo
10.
Small ; 16(4): e1905519, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31885136

RESUMO

Materials made by directed self-assembly of colloids can exhibit a rich spectrum of optical phenomena, including photonic bandgaps, coherent scattering, collective plasmonic resonance, and wave guiding. The assembly of colloidal particles with spatial selectivity is critical for studying these phenomena and for practical device fabrication. While there are well-established techniques for patterning colloidal crystals, these often require multiple steps including the fabrication of a physical template for masking, etching, stamping, or directing dewetting. Here, the direct-writing of colloidal suspensions is presented as a technique for fabrication of iridescent colloidal crystals in arbitrary 2D patterns. Leveraging the principles of convective assembly, the process can be optimized for high writing speeds (≈600 µm s-1 ) at mild process temperature (30 °C) while maintaining long-range (cm-scale) order in the colloidal crystals. The crystals exhibit structural color by grating diffraction, and analysis of diffraction allows particle size, relative grain size, and grain orientation to be deduced. The effect of write trajectory on particle ordering is discussed and insights for developing 3D printing techniques for colloidal crystals via layer-wise printing and sintering are provided.

11.
Rheumatol Int ; 40(11): 1825-1834, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32776160

RESUMO

OBJECTIVE: To describe the prevalence of and evaluate the factors associated with fatigue patients with psoriatic arthritis (PsA) in an Asian population. METHODS: We used baseline data from a registry of patients with PsA attending an outpatient clinic of a tertiary hospital in Singapore. Demographic data and disease characteristics were evaluated. Fatigue was assessed by question one of the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI-F) and the vitality domain of the Medical Outcome Survey, Short-Form 36 (SF-36 VT). We evaluated clusters of variables, and individual variables in association with fatigue. RESULTS: We included 131 patients (50.4% men, 63.4% Chinese, median PsA duration 21.0 months) with completed data for fatigue. Forty-five patients (34%) experienced severe fatigue (defined by BASDAI-F > 5/10). We used principal component analysis and identified five clusters of variables that explained 62.9% of the variance of all factors. Of these, disease activity and impact, and disease chronicity were significantly associated with BASDAI-F and SF-36 VT. In multivariable analyses, back pain, peripheral joint pain and patient global assessment were associated with BASDAI-F, whereas peripheral joint pain and mental health were associated with SF-36 VT. CONCLUSION: PsA-associated fatigue is prevalent in this Asian PsA cohort and is associated with disease activity, impact and chronicity.


Assuntos
Artrite Psoriásica/fisiopatologia , Fadiga/epidemiologia , Fadiga/fisiopatologia , Adulto , Fatores Etários , Dor nas Costas/epidemiologia , Índice de Massa Corporal , Estudos Transversais , Etnicidade , Feminino , Humanos , Masculino , Saúde Mental , Pessoa de Meia-Idade , Análise Multivariada , Medidas de Resultados Relatados pelo Paciente , Prevalência , Análise de Componente Principal , Fatores de Risco , Índice de Gravidade de Doença , Fatores Sexuais , Singapura/epidemiologia , Fatores de Tempo
12.
Anal Chem ; 91(4): 2561-2569, 2019 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-30638359

RESUMO

We describe how 4-dimensional in vivo biochemical analysis can be performed using photoacoustic contrast nanoagents that have been designed to probe both structural and chemical information in vivo, enabling noninvasive, real time, spatially resolved chemical imaging. Early chemical imaging of a patient's tumor can inform the decision of effective treatment, regarding choices of chemotherapy, radiation, or immunotherapy.


Assuntos
Técnicas de Química Analítica/métodos , Neoplasias/química , Técnicas Fotoacústicas/métodos , Animais , Humanos , Concentração de Íons de Hidrogênio , Lítio/sangue , Camundongos , Imagem Óptica/métodos , Oxigênio/sangue , Potássio/análise , Microambiente Tumoral/fisiologia
13.
Cell Microbiol ; 19(3)2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27582004

RESUMO

Type I interferons (IFNs) play a critical role in antiviral immune responses, but can be deleterious to the host during some bacterial infections. Listeria monocytogenes (Lm) induces a type I IFN response by activating cytosolic antiviral surveillance pathways. This is beneficial to the bacteria as mice lacking the type I IFN receptor (IFNAR1-/- ) are resistant to systemic infection by Lm. The mechanisms by which type I IFNs promote Lm infection are unclear. Here, we show that IFNAR1 is required for dissemination of Lm within infection foci in livers of infected mice and for efficient cell-to-cell spread in vitro in macrophages. IFNAR1 promotes ActA polarization and actin-based motility in the cytosol of host cells. Our studies suggest type I IFNs directly impact the intracellular life cycle of Lm and provide new insight into the mechanisms used by bacterial pathogens to exploit the type I IFN response.


Assuntos
Interações Hospedeiro-Patógeno , Interferon Tipo I/metabolismo , Listeria monocytogenes/crescimento & desenvolvimento , Animais , Modelos Animais de Doenças , Listeriose/microbiologia , Listeriose/patologia , Fígado/microbiologia , Fígado/patologia , Macrófagos/microbiologia , Camundongos , Receptor de Interferon alfa e beta/metabolismo
14.
Anal Chem ; 89(15): 7943-7949, 2017 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-28633520

RESUMO

Ion-selective optodes (ISOs), the optical analog of ion-selective electrodes, have played an increasingly important role in chemical and biochemical analysis. Here we extend this technique to ion-selective photoacoustic optodes (ISPAOs) that serve at the same time as fluorescence-based ISOs, and apply it specifically to potassium (K+). Notably, the potassium ion is one of the most abundant cations in biological systems, involved in numerous physiological and pathological processes. Furthermore, it has been recently reported that the presence of abnormal extracellular potassium concentrations in tumors suppresses the immune responses and thus suppresses immunotherapy. However, unfortunately, sensors capable of providing potassium images in vivo are still a future proposition. Here, we prepared an ion-selective potassium nanosensor (NS) aimed at in vivo photoacoustic (PA) chemical imaging of the extracellular environment, while being also capable of fluorescence based intracellular ion-selective imaging. This potassium nanosensor (K+ NS) modulates its optical properties (absorbance and fluorescence) according to the potassium concentration. The K+ NS is capable of measuring potassium, in the range of 1 mM to 100 mM, with high sensitivity and selectivity, by ISPAO based measurements. Also, a near infrared dye surface modified K+ NS allows fluorescence-based potassium sensing in the range of 20 mM to 1 M. The K+ NS serves thus as both PA and fluorescence based nanosensor, with response across the biologically relevant K+ concentrations, from the extracellular 5 mM typical values (through PA imaging) to the intracellular 150 mM typical values (through fluorescence imaging).


Assuntos
Nanoestruturas/química , Técnicas Fotoacústicas/métodos , Potássio/análise , Aminas/química , Cátions/química , Corantes Fluorescentes/química , Células HeLa , Humanos , Eletrodos Seletivos de Íons , Micelas , Microscopia de Fluorescência , Poloxâmero/química
15.
Eur J Neurosci ; 44(1): 1761-70, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26990801

RESUMO

Opioids induce rewarding and locomotor effects by inhibiting rostromedial tegmental GABA neurons that express µ-opioid and nociceptin receptors. These GABA neurons then strongly inhibit dopamine neurons. Opioid-induced reward, locomotion and dopamine release also depend on pedunculopontine and laterodorsal tegmental cholinergic and glutamate neurons, many of which project to and activate ventral tegmental area dopamine neurons. Here we show that laterodorsal tegmental and pedunculopontine cholinergic neurons project to both rostromedial tegmental nucleus and ventral tegmental area, and that M4 muscarinic receptors are co-localized with µ-opioid receptors associated with rostromedial tegmental GABA neurons. To inhibit or excite rostromedial tegmental GABA neurons, we utilized adeno-associated viral vectors and DREADDs to express designed muscarinic receptors (M4D or M3D respectively) in GAD2::Cre mice. In M4D-expressing mice, clozapine-N-oxide increased morphine-induced, but not vehicle-induced, locomotion. In M3D-expressing mice, clozapine-N-oxide blocked morphine-induced, but not vehicle-induced, locomotion. We propose that cholinergic inhibition of rostromedial tegmental GABA neurons via M4 muscarinic receptors facilitates opioid inhibition of the same neurons. This model explains how mesopontine cholinergic systems and muscarinic receptors in the rostromedial tegmental nucleus and ventral tegmental area are important for dopamine-dependent and dopamine-independent opioid-induced rewards and locomotion.


Assuntos
Neurônios GABAérgicos/metabolismo , Locomoção , Morfina/farmacologia , Receptor Muscarínico M4/metabolismo , Tegmento Mesencefálico/metabolismo , Animais , Neurônios Colinérgicos/efeitos dos fármacos , Neurônios Colinérgicos/fisiologia , Clozapina/farmacologia , Antagonistas GABAérgicos/farmacologia , Neurônios GABAérgicos/efeitos dos fármacos , Neurônios GABAérgicos/fisiologia , Masculino , Camundongos , Agonistas Muscarínicos/farmacologia , Receptor Muscarínico M4/agonistas , Receptor Muscarínico M4/genética , Receptores Opioides mu/agonistas , Receptores Opioides mu/genética , Receptores Opioides mu/metabolismo , Recompensa , Tegmento Mesencefálico/citologia , Tegmento Mesencefálico/efeitos dos fármacos , Tegmento Mesencefálico/fisiologia
16.
Small ; 12(33): 4531-40, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27389580

RESUMO

Controlling sub-10 nm ligament sizes and open-shell structure in nanoporous gold (NPG) to achieve strained lattice is critical in enhancing catalytic activity, but it remains a challenge due to poor control of reaction kinetics in conventional dealloying approach. Herein, a ligament size-controlled synthesis of open-shell NPG bowls (NPGB) through hetero-epitaxial growth of NPGB on AgCl is reported. The ligament size in NPGB is controlled from 6 to 46 nm by varying the hydroquinone to HAuCl4 ratio. The Williamson-Hall analysis demonstrates a higher lattice strain in smaller ligament size. In particular, NPGB with 6 nm (NPGB 6) ligament size possess the highest strain of 15.4 × 10(-3) , which is nearly twice of conventional 2D NPG sheets (≈8.8 × 10(-3) ). The presence of high surface energy facets in NPGBs is also envisaged. The best electrocatalytic activity toward methanol oxidation is observed in NPGB 6 (27.8 µA µg(-1) ), which is ≈9-fold and 3-fold higher than 8 nm solid Au nanoparticles, and conventional NPG sheets. The excellent catalytic activity in NPGB 6 is attributed to the open-shell structure, lattice strain, and higher electro-active surface area, allowing efficient exposure of catalytic active sites to facilitate the methanol oxidation. The results offer a potential strategy for designing next generation electrocatalysts.

17.
J Am Chem Soc ; 136(18): 6684-92, 2014 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-24702183

RESUMO

Single-phase Cu2ZnSnS4 (CZTS) is an essential prerequisite toward a high-efficiency thin-film solar cell device. Herein, the selective phase formation of single-phase CZTS nanoparticles by ligand control is reported. Surface-enhanced Raman scattering (SERS) spectroscopy is demonstrated for the first time as a characterization tool for nanoparticles to differentiate the mixed compositional phase (e.g., CZTS, CTS, and ZnS), which cannot be distinguished by X-ray diffraction. Due to the superior selectivity and sensitivity of SERS, the growth mechanism of CZTS nanoparticle formation by hot injection is revealed to involve three growth steps. First, it starts with nucleation of Cu(2-x)S nanoparticles, followed by diffusion of Sn(4+) into Cu(2-x)S nanoparticles to form the Cu3SnS4 (CTS) phase and diffusion of Zn(2+) into CTS nanoparticles to form the CZTS phase. In addition, it is revealed that single-phase CZTS nanoparticles can be obtained via balancing the rate of CTS phase formation and diffusion of Zn(2+) into the CTS phase. We demonstrate that this balance can be achieved by 1 mL of thiol with Cu(OAc)2, Sn(OAc)4, and Zn(acac)2 metal salts to synthesize the CZTS phase without the presence of a detectable binary/ternary phase with SERS.

18.
Phys Chem Chem Phys ; 16(48): 26983-90, 2014 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-25380327

RESUMO

An analytical platform with an ultratrace detection limit in the atto-molar (aM) concentration range is vital for forensic, industrial and environmental sectors that handle scarce/highly toxic samples. Superhydrophobic surface-enhanced Raman scattering (SERS) platforms serve as ideal platforms to enhance detection sensitivity by reducing the random spreading of aqueous solution. However, the fabrication of superhydrophobic SERS platforms is generally limited due to the use of sophisticated and expensive protocols and/or suffers structural and signal inconsistency. Herein, we demonstrate a high-throughput fabrication of a stable and uniform superhydrophobic SERS platform for ultratrace molecular sensing. Large-area box-like micropatterns of the polymeric surface are first fabricated using capillary force lithography (CFL). Subsequently, plasmonic properties are incorporated into the patterned surfaces by decorating with Ag nanocubes using the Langmuir-Schaefer technique. To create a stable superhydrophobic SERS platform, an additional 25 nm Ag film is coated over the Ag nanocube-decorated patterned template followed by chemical functionalization with perfluorodecanethiol. Our resulting superhydrophobic SERS platform demonstrates excellent water-repellency with a static contact angle of 165° ± 9° and a consequent analyte concentration factor of 59-fold, as compared to its hydrophilic counterpart. By combining the analyte concentration effect of superhydrophobic surfaces with the intense electromagnetic "hot spots" of Ag nanocubes, our superhydrophobic SERS platform achieves an ultra-low detection limit of 10(-17) M (10 aM) for rhodamine 6G using just 4 µL of analyte solutions, corresponding to an analytical SERS enhancement factor of 10(13). Our fabrication protocol demonstrates a simple, cost- and time-effective approach for the large-scale fabrication of a superhydrophobic SERS platform for ultratrace molecular detection.

19.
Nat Commun ; 15(1): 2513, 2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38514625

RESUMO

In multiple myeloma, abnormal plasma cells establish oncogenic niches within the bone marrow by engaging the NF-κB pathway to nurture their survival while they accumulate pro-proliferative mutations. Under these conditions, many cases eventually develop genetic abnormalities endowing them with constitutive NF-κB activation. Here, we find that sustained NF-κB/p52 levels resulting from such mutations favours the recruitment of enhancers beyond the normal B-cell repertoire. Furthermore, through targeted disruption of p52, we characterise how such enhancers are complicit in the formation of super-enhancers and the establishment of cis-regulatory interactions with myeloma dependencies during constitutive activation of p52. Finally, we functionally validate the pathological impact of these cis-regulatory modules on cell and tumour phenotypes using in vitro and in vivo models, confirming RGS1 as a p52-dependent myeloma driver. We conclude that the divergent epigenomic reprogramming enforced by aberrant non-canonical NF-κB signalling potentiates transcriptional programs beneficial for multiple myeloma progression.


Assuntos
Mieloma Múltiplo , NF-kappa B , Humanos , NF-kappa B/genética , NF-kappa B/metabolismo , Mieloma Múltiplo/genética , Mieloma Múltiplo/metabolismo , Transcriptoma , Epigenoma , Transdução de Sinais/genética , Subunidade p52 de NF-kappa B/metabolismo
20.
Nat Commun ; 15(1): 3120, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38600106

RESUMO

Salmonella utilizes a type 3 secretion system to translocate virulence proteins (effectors) into host cells during infection1. The effectors modulate host cell machinery to drive uptake of the bacteria into vacuoles, where they can establish an intracellular replicative niche. A remarkable feature of Salmonella invasion is the formation of actin-rich protuberances (ruffles) on the host cell surface that contribute to bacterial uptake. However, the membrane source for ruffle formation and how these bacteria regulate membrane mobilization within host cells remains unclear. Here, we show that Salmonella exploits membrane reservoirs for the generation of invasion ruffles. The reservoirs are pre-existing tubular compartments associated with the plasma membrane (PM) and are formed through the activity of RAB10 GTPase. Under normal growth conditions, membrane reservoirs contribute to PM homeostasis and are preloaded with the exocyst subunit EXOC2. During Salmonella invasion, the bacterial effectors SipC, SopE2, and SopB recruit exocyst subunits from membrane reservoirs and other cellular compartments, thereby allowing exocyst complex assembly and membrane delivery required for bacterial uptake. Our findings reveal an important role for RAB10 in the establishment of membrane reservoirs and the mechanisms by which Salmonella can exploit these compartments during host cell invasion.


Assuntos
Infecções por Salmonella , Salmonella typhimurium , Humanos , Salmonella typhimurium/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Infecções por Salmonella/microbiologia , Membrana Celular/metabolismo , Membranas/metabolismo , Células HeLa
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