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1.
Proc Natl Acad Sci U S A ; 119(9)2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35210364

RESUMO

Adult T-cell leukemia/lymphoma (ATL) is an aggressive malignancy caused by human T-cell leukemia virus type 1 (HTLV-1) infection. HTLV-1 exerts its oncogenic functions by interacting with signaling pathways involved in cell proliferation and transformation. Dysregulation of the Hippo/YAP pathway is associated with multiple cancers, including virus-induced malignancies. In the present study, we observe that expression of YAP, which is the key effector of Hippo signaling, is elevated in ATL cells by the action of the HTLV-1 Tax protein. YAP transcriptional activity is remarkably enhanced in HTLV-1-infected cells and ATL patients. In addition, Tax activates the YAP protein via a mechanism involving the NF-κB/p65 pathway. As a mechanism for this cross talk between the Hippo and NF-κB pathways, we found that p65 abrogates the interaction between YAP and LATS1, leading to suppression of YAP phosphorylation, inhibition of ubiquitination-dependent degradation of YAP, and YAP nuclear accumulation. Finally, knockdown of YAP suppresses the proliferation of ATL cells in vitro and tumor formation in ATL-engrafted mice. Taken together, our results suggest that p65-induced YAP activation is essential for ATL pathogenesis and implicate YAP as a potential therapeutic target for ATL treatment.


Assuntos
Carcinogênese , Proteínas de Ciclo Celular/metabolismo , Vírus Linfotrópico T Tipo 1 Humano/fisiologia , NF-kappa B/metabolismo , Fatores de Transcrição/metabolismo , Núcleo Celular/metabolismo , Proliferação de Células , Produtos do Gene tax/metabolismo , Humanos , Células Jurkat , Fosforilação , Ubiquitinação , Regulação para Cima
2.
Proc Natl Acad Sci U S A ; 119(36): e2203452119, 2022 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-36037342

RESUMO

The contribution of deregulated chromatin architecture, including topologically associated domains (TADs), to cancer progression remains ambiguous. CCCTC-binding factor (CTCF) is a central regulator of higher-order chromatin structure that undergoes copy number loss in over half of all breast cancers, but the impact of this defect on epigenetic programming and chromatin architecture remains unclear. We find that under physiological conditions, CTCF organizes subTADs to limit the expression of oncogenic pathways, including phosphatidylinositol 3-kinase (PI3K) and cell adhesion networks. Loss of a single CTCF allele potentiates cell invasion through compromised chromatin insulation and a reorganization of chromatin architecture and histone programming that facilitates de novo promoter-enhancer contacts. However, this change in the higher-order chromatin landscape leads to a vulnerability to inhibitors of mTOR. These data support a model whereby subTAD reorganization drives both modification of histones at de novo enhancer-promoter contacts and transcriptional up-regulation of oncogenic transcriptional networks.


Assuntos
Montagem e Desmontagem da Cromatina , Regulação Neoplásica da Expressão Gênica , Invasividade Neoplásica , Fator de Ligação a CCCTC/metabolismo , Carcinogênese/genética , Cromatina/genética , Cromatina/metabolismo , Humanos , Invasividade Neoplásica/genética , Invasividade Neoplásica/patologia , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Regiões Promotoras Genéticas
3.
FASEB J ; 37(12): e23269, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37889852

RESUMO

Viruses deploy multiple strategies to suppress the host innate immune response to facilitate viral replication and pathogenesis. Typical G3BP1+ stress granules (SGs) are usually formed in host cells after virus infection to restrain viral translation and to stimulate innate immunity. Thus, viruses have evolved various mechanisms to inhibit SGs or to repurpose SG components such as G3BP1. Previous studies showed that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection inhibited host immunity during the early stage of COVID-19. However, the precise mechanism is not yet well understood. Here we showed that the SARS-CoV-2 nucleocapsid (SARS2-N) protein suppressed the double-stranded RNA (dsRNA)-induced innate immune response, concomitant with inhibition of SGs and the induction of atypical SARS2-N+ /G3BP1+ foci (N+ foci). The SARS2-N protein-induced formation of N+ foci was dependent on the ability of its ITFG motif to hijack G3BP1, which contributed to suppress the innate immune response. Importantly, SARS2-N protein facilitated viral replication by inducing the formation of N+ foci. Viral mutations within SARS2-N protein that impair the formation of N+ foci are associated with the inability of the SARS2-N protein to suppress the immune response. Taken together, our study has revealed a novel mechanism by which SARS-CoV-2 suppresses the innate immune response via induction of atypical N+ foci. We think that this is a critical strategy for viral pathogenesis and has potential therapeutic implications.


Assuntos
COVID-19 , DNA Helicases , Humanos , SARS-CoV-2/metabolismo , RNA Helicases/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose , Grânulos de Estresse , Proteínas com Motivo de Reconhecimento de RNA/metabolismo , Imunidade Inata , Replicação Viral , Proteínas do Nucleocapsídeo/metabolismo
4.
Nucleic Acids Res ; 50(15): 8441-8458, 2022 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-35947648

RESUMO

Defining the impact of missense mutations on the recognition of DNA motifs is highly dependent on bioinformatic tools that define DNA binding elements. However, classical motif analysis tools remain limited in their capacity to identify subtle changes in complex binding motifs between distinct conditions. To overcome this limitation, we developed a new tool, MoMotif, that facilitates a sensitive identification, at the single base-pair resolution, of complex, or subtle, alterations to core binding motifs, discerned from ChIP-seq data. We employed MoMotif to define the previously uncharacterized recognition motif of CTCF zinc-finger 1 (ZF1), and to further define the impact of CTCF ZF1 mutation on its association with chromatin. Mutations of CTCF ZF1 are exclusive to breast cancer and are associated with metastasis and therapeutic resistance, but the underlying mechanisms are unclear. Using MoMotif, we identified an extension of the CTCF core binding motif, necessitating a functional ZF1 to bind appropriately. Using a combination of ChIP-Seq and RNA-Seq, we discover that the inability to bind this extended motif drives an altered transcriptional program associated with the oncogenic phenotypes observed clinically. Our study demonstrates that MoMotif is a powerful new tool for comparative ChIP-seq analysis and characterising DNA-protein contacts.


Assuntos
Cromatina , Zinco , Fator de Ligação a CCCTC/genética , Fator de Ligação a CCCTC/metabolismo , Zinco/metabolismo , Cromatina/genética , DNA/química , Mutação , Sítios de Ligação
5.
Molecules ; 29(9)2024 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-38731625

RESUMO

Upon a variety of environmental stresses, eukaryotic cells usually recruit translational stalled mRNAs and RNA-binding proteins to form cytoplasmic condensates known as stress granules (SGs), which minimize stress-induced damage and promote stress adaptation and cell survival. SGs are hijacked by cancer cells to promote cell survival and are consequently involved in the development of anticancer drug resistance. However, the design and application of chemical compounds targeting SGs to improve anticancer drug efficacy have rarely been studied. Here, we developed two types of SG inhibitory peptides (SIPs) derived from SG core proteins Caprin1 and USP10 and fused with cell-penetrating peptides to generate TAT-SIP-C1/2 and SIP-U1-Antp, respectively. We obtained 11 SG-inducing anticancer compounds from cell-based screens and explored the potential application of SIPs in overcoming resistance to the SG-inducing anticancer drug sorafenib. We found that SIPs increased the sensitivity of HeLa cells to sorafenib via the disruption of SGs. Therefore, anticancer drugs which are competent to induce SGs could be combined with SIPs to sensitize cancer cells, which might provide a novel therapeutic strategy to alleviate anticancer drug resistance.


Assuntos
Antineoplásicos , Sorafenibe , Grânulos de Estresse , Humanos , Sorafenibe/farmacologia , Antineoplásicos/farmacologia , Antineoplásicos/química , Grânulos de Estresse/metabolismo , Células HeLa , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Peptídeos/farmacologia , Peptídeos/química , Sobrevivência Celular/efeitos dos fármacos , Ubiquitina Tiolesterase/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Neoplasias/patologia , Linhagem Celular Tumoral , Peptídeos Penetradores de Células/farmacologia , Peptídeos Penetradores de Células/química
6.
J Med Virol ; 95(9): e29065, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37661566

RESUMO

Human T-cell leukemia virus type 1 (HTLV-1) is an oncogenic retrovirus that causes adult T-cell leukemia/lymphoma (ATL). HTLV-1 encodes Tax protein that activates transcription from viral long terminal repeats (LTR). Multiple cofactors are involved in the regulation of HTLV-1 transcription via association with Tax. Yes-associated protein (YAP), which is the key effector of Hippo pathway, is elevated and activated in ATL cells. In this study, we reported that YAP protein suppressed Tax activation of HTLV-1 5' LTR but not 3' LTR. The activation of the 5' LTR by Tax was potentiated when YAP was depleted. Moreover, overexpression of YAP repressed HTLV-1 plus-strand viral gene expression and virion production, whereas compromising YAP by RNA inference augmented the expression of HTLV-1 protein. As mechanisms of YAP-mediated viral transcription inhibition, we found that YAP interacted with Tax, and prevented the association between Tax and p300. It finally led to the inhibition of recruitment of Tax to the Tax-responsive element in the 5' LTR of HTLV-1. Taken together, our results demonstrate the negative regulatory function of YAP in Tax activation of HTLV-1 transcription. It may achieve sufficient transcriptional repression to maintain persistent infection and long-term latency of HTLV-1 in the host cells.


Assuntos
Vírus Linfotrópico T Tipo 1 Humano , Leucemia de Células T , Adulto , Humanos , Vírus Linfotrópico T Tipo 1 Humano/genética , Expressão Gênica , Infecção Persistente , RNA
7.
Molecules ; 28(7)2023 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-37049786

RESUMO

3C proteases (3Cpros) of picornaviruses and 3C-like proteases (3CLpros) of coronaviruses and caliciviruses represent a group of structurally and functionally related viral proteases that play pleiotropic roles in supporting the viral life cycle and subverting host antiviral responses. The design and screening for 3C/3CLpro inhibitors may contribute to the development broad-spectrum antiviral therapeutics against viral diseases related to these three families. However, current screening strategies cannot simultaneously assess a compound's cytotoxicity and its impact on enzymatic activity and protease-mediated physiological processes. The viral induction of stress granules (SGs) in host cells acts as an important antiviral stress response by blocking viral translation and stimulating the host immune response. Most of these viruses have evolved 3C/3CLpro-mediated cleavage of SG core protein G3BP1 to counteract SG formation and disrupt the host defense. Yet, there are no SG-based strategies screening for 3C/3CLpro inhibitors. Here, we developed a fluorescence resonance energy transfer (FRET) and SG dual-based system to screen for 3C/3CLpro inhibitors in living cells. We took advantage of FRET to evaluate the protease activity of poliovirus (PV) 3Cpro and live-monitor cellular SG dynamics to cross-verify its effect on the host antiviral response. Our drug screen uncovered a novel role of Telaprevir and Trifluridine as inhibitors of PV 3Cpro. Moreover, Telaprevir and Trifluridine also modulated 3Cpro-mediated physiological processes, including the cleavage of host proteins, inhibition of the innate immune response, and consequent facilitation of viral replication. Taken together, the FRET and SG dual-based system exhibits a promising potential in the screening for inhibitors of viral proteases that cleave G3BP1.


Assuntos
Transferência Ressonante de Energia de Fluorescência , Inibidores de Protease Viral , Humanos , DNA Helicases/metabolismo , Trifluridina , Grânulos de Estresse , Proteínas Virais/metabolismo , RNA Helicases/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Proteínas com Motivo de Reconhecimento de RNA/metabolismo , Antivirais/farmacologia , Inibidores de Proteases/farmacologia
8.
J Am Chem Soc ; 144(38): 17457-17467, 2022 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-36102877

RESUMO

Here, we report the synthesis of two-dimensional (2D) layered metal-organic framework (MOF) nanoparticle (NP) superstructures via an ice-templating strategy. MOF NP monolayers and bilayers can be obtained by regulating the concentration of colloidal MOF NPs without any external fields during self-assembly. Adjacent polyhedral MOF NPs are packed and aligned through crystalline facets, resulting in the formation of a quasi-ordered array superstructure. The morphology of the MOF layers is well preserved when subjected to pyrolysis, and the obtained carbon NPs have hollow interiors driven by the outward contraction of MOF precursors during pyrolysis. With the advantages of large surface areas, hierarchical porosity, high exposure of active sites, and fast electron transport of the 2D layered structure, the mono- and bilayered carbon NP superstructures show better oxygen reduction activity than isolated carbon particles in alkaline media. Our work demonstrates that ice-templating is a powerful strategy to fabricate superstructures of various MOFs and their derivatives.

9.
Anal Chem ; 94(8): 3708-3717, 2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35172575

RESUMO

Nowadays, aggregation quenching of most organic photosensitizers in aqueous media seriously restricts analytical and biomedical applications of photoelectrochemical (PEC) sensors. In this work, an aggregation-enhanced PEC photosensitizer was prepared by electrostatically bonding protoporphyrin IX (PPIX) with an ionic liquid of 1-butyl-3-methylimidazole tetrafluoroborate ([BMIm][BF4]), termed as PPIX-[BMIm] for clarity. The resultant PPIX-[BMIm] showed weak photocurrent in pure dimethyl sulfoxide (DMSO, good solvent), while the PEC signals displayed a 44.1-fold enhancement in a water (poor solvent)/DMSO binary solvent with a water fraction (fw) of 90%. Such PEC-enhanced mechanism was critically studied by electrochemistry and density functional theory (DFT) calculation in some detail. Afterward, a label-free PEC cytosensor was built for ultrasensitive bioassay of acute lymphoblastic leukemia (molt-4) cells by electrodepositing Au nanoparticles (Au NPs) on the PPIX-[BMIm] aggregates and sequential assembly of protein tyrosine kinase (PTK) aptamer DNA (aptDNA). The resultant cytosensor showed a wide linear range (300 to 3 × 105 cells mL-1) with a limit of detection (LOD) as low as 63 cells mL-1. The aggregation-enhanced PEC performance offers a valuable and practical pathway for synthesis of advanced organic photosensitizer to explore its PEC applications in early diagnosis of tumors.


Assuntos
Técnicas Biossensoriais , Líquidos Iônicos , Nanopartículas Metálicas , Técnicas Eletroquímicas , Ouro , Fármacos Fotossensibilizantes , Protoporfirinas , Eletricidade Estática
10.
Anal Chem ; 94(35): 12240-12247, 2022 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-35994715

RESUMO

Hepatocellular carcinoma is a life-threatening malignant tumor found around the world for its high morbidity and mortality. Therefore, it is of great importance for sensitive analysis of liver cancer cells (HepG2 cells) in clinical diagnosis and biomedical research. To fulfill this demand, hollow CdIn2S4/In2S3 heterostructured microspheres (termed CdIn2S4/In2S3 for clarity) were prepared by a two-step hydrothermal strategy and applied for building a novel photoelectrochemical (PEC) cytosensor for ultrasensitive and accurate detection of HepG2 cells through specific recognition of CD133 protein on the cell surface with the respective aptamer. The optical properties of CdIn2S4/In2S3 were investigated by UV-vis diffuse reflectance spectroscopy (DRS) and PEC technology. By virtue of their appealing PEC characteristics, the resultant PEC sensor exhibited a wider dynamic linear range from 1 × 102 to 2 × 105 cells mL-1 with a lower limit of detection (LOD, 23 cells mL-1), combined by evaluating the expression level of CD133 protein stimulated by metformin as a benchmarked inhibitor. This work opens a valuable and feasible avenue for sensitive detection of diverse tumor cells, holding great potential in early clinical diagnosis and treatment coupled by screening inhibitors.


Assuntos
Técnicas Biossensoriais , Técnicas Eletroquímicas , Técnicas Eletroquímicas/métodos , Células Hep G2 , Humanos , Microesferas
11.
Ann Vasc Surg ; 79: 139-144, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34644658

RESUMO

OBJECTIVE: Peripheral artery disease (PAD) is often caused by atherosclerosis. However, causes other than atherosclerosis is often overlooked. Popliteal artery entrapment syndrome (PAES) and popliteal artery adventitial cystic disease (PACD) are two common nonatheromatous causes of claudication and critical limb ischemia. The purpose of this study is to present early results of treatment of PAES and PACD involving the lower limbs. METHODS: From December 2019 to February 2021, 10 patients with PAES underwent surgeries, and 1 patient with PAES received conservative treatment. 2 patients with PACD underwent surgery. Patient data including age, gender, etiology of vascular pathology, diseased vessel, surgical method, and hemodynamic status were collected retrospectively. RESULTS: The mean follow-up duration was 5.64 ± 3.72 months (range, 1-12 months). All patients had their symptoms improved or resolved. The success rate of surgery was 100%, the rate of freedom from reintervention for any reason was 100%. There were no death, bleeding, embolism, or skin ulcers during late follow-up. CONCLUSIONS: PAES and PACD require early diagnosis and intervention, and early surgery may lead to good early- and mid-term results.


Assuntos
Tratamento Conservador , Doença Arterial Periférica/terapia , Síndrome do Aprisionamento da Artéria Poplítea/terapia , Artéria Poplítea/cirurgia , Procedimentos Cirúrgicos Vasculares , Adolescente , Adulto , China , Tratamento Conservador/efeitos adversos , Feminino , Hemodinâmica , Humanos , Masculino , Pessoa de Meia-Idade , Doença Arterial Periférica/diagnóstico por imagem , Doença Arterial Periférica/fisiopatologia , Artéria Poplítea/diagnóstico por imagem , Artéria Poplítea/fisiopatologia , Síndrome do Aprisionamento da Artéria Poplítea/diagnóstico por imagem , Síndrome do Aprisionamento da Artéria Poplítea/fisiopatologia , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento , Procedimentos Cirúrgicos Vasculares/efeitos adversos
12.
Eur Surg Res ; 63(4): 294-301, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35605582

RESUMO

Esophagogastric anastomosis stricture is one of the most common postoperative complications after esophagectomy; yet, its pathogenesis is still not fully understood, and the treatment and prevention of anastomotic stricture are limited due to the lack of a proper animal model. The insufficient blood supply in the gastric tube is considered a risk factor for postoperative anastomotic strictures. In this study, we used thermal imaging to develop a stable rodent model with esophagogastric anastomotic stricture caused by ischemia. Briefly, 30 male Sprague-Dawley rats have been divided into the control group and the ischemia group. The esophagogastric ischemia anastomosis was performed with the help of intraoperative thermal imaging to identify the poor perfusion area. An unpaired t test with Welch's correction was used to analyze the difference between the two groups. On postoperative day 84, in the control group, no anastomosis stricture was observed, while in the ischemia group, 12 out of 15 animals (80%) developed obvious anastomosis stricture which could not let a 2.7-mm endoscope pass through. The diameter of the anastomosis in the control group and the ischemia group were 2.80 ± 0.15 mm and 1.73 ± 0.44 mm (p < 0.01), respectively (evaluated by endoscopy examination and barium radiography). H&E stain and Masson's trichrome showed that the anastomosis in the ischemia group had more connective tissue hyperplasia and collagen deposition than control group. Thus, this new rat model can be used as a platform to further investigate the potential interventions for prevention of esophagogastric anastomotic stricture.


Assuntos
Neoplasias Esofágicas , Masculino , Ratos , Animais , Constrição Patológica/complicações , Constrição Patológica/cirurgia , Neoplasias Esofágicas/cirurgia , Ratos Sprague-Dawley , Esofagectomia/efeitos adversos , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/prevenção & controle , Anastomose Cirúrgica/efeitos adversos , Anastomose Cirúrgica/métodos , Isquemia/etiologia , Fístula Anastomótica/etiologia , Fístula Anastomótica/prevenção & controle
13.
Sensors (Basel) ; 22(14)2022 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-35890834

RESUMO

Photoplethysmography is a widely used technique to noninvasively assess heart rate, blood pressure, and oxygen saturation. This technique has considerable potential for further applications-for example, in the field of physiological and mental health monitoring. However, advanced applications of photoplethysmography have been hampered by the lack of accurate and reliable methods to analyze the characteristics of the complex nonlinear dynamics of photoplethysmograms. Methods of nonlinear time series analysis may be used to estimate the dynamical characteristics of the photoplethysmogram, but they are highly influenced by the length of the time series, which is often limited in practical photoplethysmography applications. The aim of this study was to evaluate the error in the estimation of the dynamical characteristics of the photoplethysmogram associated with the limited length of the time series. The dynamical properties were evaluated using recurrence quantification analysis, and the estimation error was computed as a function of the length of the time series. Results demonstrated that properties such as determinism and entropy can be estimated with an error lower than 1% even for short photoplethysmogram recordings. Additionally, the lower limit for the time series length to estimate the average prediction time was computed.


Assuntos
Fotopletismografia , Processamento de Sinais Assistido por Computador , Algoritmos , Pressão Sanguínea/fisiologia , Frequência Cardíaca/fisiologia , Fotopletismografia/métodos
14.
Cancer Sci ; 112(4): 1376-1382, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33615636

RESUMO

Enhancer of zeste homolog 2 (EZH2) is the catalytic subunit of polycomb repressive complex 2 (PRC2). Dysregulation of EZH2 causes alteration of gene expression and functions, thereby promoting cancer development. The regulatory function of EZH2 varies across different tumor types. The canonical role of EZH2 is gene silencing through catalyzing the trimethylation of lysine 27 of histone H3 (H3K27me3) in a PRC2-dependent manner. Accumulating evidence indicates that EZH2 has an H3K27me3-independent function as a transcriptional coactivator and plays a critical role in cancer initiation, development, and progression. In this review, we summarize the regulation and function of EZH2 and focus on the current understanding of the noncanonical role of EZH2 in cancer.


Assuntos
Proteína Potenciadora do Homólogo 2 de Zeste/genética , Neoplasias/genética , Animais , Expressão Gênica/genética , Inativação Gênica/fisiologia , Histonas/genética , Humanos , Complexo Repressor Polycomb 2/genética
15.
NMR Biomed ; 34(6): e4507, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33754420

RESUMO

1 H-MRSI is commonly performed with gradient phase encoding, due to its simplicity and minimal radio frequency (RF) heating (specific absorption rate). Its two well-known main problems-(i) "voxel bleed" due to the intrinsic point-spread function, and (ii) chemical shift displacement error (CSDE) when slice-selective RF pulses are used, which worsens with increasing volume of interest (VOI) size-have long become accepted as unavoidable. Both problems can be mitigated with Hadamard multislice RF encoding. This is demonstrated and quantified with numerical simulations, in a multislice phantom and in five healthy young adult volunteers at 3 T, targeting a 2-cm thick temporal lobe VOI through the bilateral hippocampus. This frequently targeted region (e.g. in epilepsy and Alzheimer's disease) is subject to strong, 1-2 ppm.cm-1 regional B0, susceptibility gradients that can dramatically reduce the signal-to-noise ratio (SNR) and water suppression effectiveness. The chemical shift imaging (CSI) sequence used a 3-ms Shinnar-Le Roux (SLR) 90° RF pulse, acquiring eight steps in the slice direction. The Hadamard sequence acquired two overlapping slices using the same SLR 90° pulses, under twofold stronger gradients that proportionally halved the CSDE. Both sequences used 2D 20 × 20 rosette spectroscopic imaging (RSI) for in-plane spatial localization and both used RF and gradient performance characteristics that are easily met by all modern MRI instruments. The results show that Hadamard spectroscopic imaging (HSI) suffered dramatically less signal bleed within the VOI compared with CSI (<1% vs. approximately 26% in simulations; and 5%-8% vs. >50%) in a phantom specifically designed to test these effects. The voxels' SNR per unit volume per unit time was also 40% higher for HSI. In a group of five healthy volunteers, we show that HSI with in-plane 2D-RSI facilitates fast, 3D multivoxel encoding at submilliliter spatial resolution, over the bilateral human hippocampus, in under 10 min, with negligible CSDE, spectral and spatial contamination and more than 6% improved SNR per unit time per unit volume.


Assuntos
Imageamento Tridimensional , Espectroscopia de Prótons por Ressonância Magnética , Lobo Temporal/diagnóstico por imagem , Adulto , Simulação por Computador , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Imagens de Fantasmas , Razão Sinal-Ruído , Adulto Jovem
16.
Sensors (Basel) ; 20(5)2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-32143333

RESUMO

An Ag/AgCl electrode used as a corrosion sensor in a reinforced concrete structure isconsidered as having good application prospect. However, its performance under complexconditions, such as dry-wet cycle condition, is not affirmed. In the current study, the performanceof Ag/AgCl as chloride selective electrode in mortar exposed to dry-wet cycle condition wasinvestigated. A simple Ag/AgCl electrode was prepared and fabricated by electrochemicalanodization. These Ag/AgCl electrodes were embedded into a mortar specimen with temperaturesensors, humidity sensors and anode ladder monitoring system (ALS). After 28 d curing time, theupper surface of mortar specimen was wetted (with 5% NaCl solution) and dried regularly. Theobtained results indicate that Ag/AgCl electrode responds to the ingress of chloride ion, sensitively.The chloride ion concentration variation can be reflected by the potential trend. Furthermore, thebalance potential of Ag/AgCl electrodes is influenced by dry-wet cycles. Compared with ALS, itdemonstrates that Ag/AgCl electrodes are more sensitive to chloride. The research provides the keyelement for the specific application of Ag/AgCl electrode for corrosion monitoring in the future.

17.
Retrovirology ; 16(1): 5, 2019 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-30782173

RESUMO

BACKGROUND: Adult T-cell leukemia (ATL) is an aggressive neoplasm caused by human T-cell leukemia virus type 1 (HTLV-1). ATL carries a poor prognosis due to chemotherapy resistance. Thus, it is urgent to develop new treatment strategies. Hypericin (HY) is a new-type of photosensitizer in the context of photodynamic therapy (PDT) due to its excellent photosensitizing properties and anti-tumor activities. RESULTS: In the present study, we investigated the efficacy of hypericin in ATL cells. Clinically achievable concentrations of hypericin in association with PDT induced the inhibition of cell proliferation in ATL cell lines with minimal effect on peripheral blood CD4+ T lymphocytes. Moreover, hypericin-PDT treatment caused apoptosis and G2/M phase cell cycle arrest in leukemic cells. Western blot analyses revealed that hypericin-PDT treatment resulted in downregulation of Bcl-2 and enhanced the expression of Bad, cytochrome C, and AIF. Cleavage of caspases-3/-7/-9/-8, Bid, and PARP was increased in hypericin-PDT-treated ATL cells. In a luciferase assay, hypericin-PDT treatment was able to activate the promoter activity of Bax and p53, resulting in enhanced expression of Bax and p53 proteins. Finally, hypericin-PDT treatment suppressed the expression of viral protein HBZ and Tax by blocking the promoter activity via HTLV-1 5'LTR and 3'LTR. CONCLUSIONS: Our results revealed that hypericin-PDT is highly effective against ATL cells by induction of apoptosis and suppression of viral transcription. These studies highlight the promising use of hypericin-PDT as a targeted therapy for ATL.


Assuntos
Apoptose/efeitos dos fármacos , Vírus Linfotrópico T Tipo 1 Humano/efeitos dos fármacos , Leucemia-Linfoma de Células T do Adulto/tratamento farmacológico , Luz , Perileno/análogos & derivados , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacologia , Antracenos , Apoptose/efeitos da radiação , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Vírus Linfotrópico T Tipo 1 Humano/efeitos da radiação , Humanos , Modelos Biológicos , Perileno/farmacologia , Transcrição Gênica/efeitos dos fármacos , Transcrição Gênica/efeitos da radiação , Ensaio Tumoral de Célula-Tronco
18.
Biochem Biophys Res Commun ; 512(3): 598-603, 2019 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-30914196

RESUMO

Human T-cell leukemia virus 1 (HTLV-1), an oncogenic retrovirus, and Notch1 signaling, implicated in tumor formation and progression, are both associated with the development of adult T-cell leukemia (ATL). Here we explored the possibility of a mechanistic link between the two. We observed that the expression of Notch intracellular domain (NICD) was elevated in HTLV-1 infected cell lines. Knocking down of Notch1 in ATL cells repressed cellular proliferation and tumor formation both in vitro and in vivo. As a mechanism for these actions, we found that Tax activated Notch1 signaling by prolonging the half-life of NICD. We then showed that Tax, NICD, and RBP-jκ formed a ternary complex, that Tax enhanced the association of NICD with RBP-jκ, and that Tax, NICD, and RBP-jκ were bound to RBP-jκ-responsive elements. Hence, our results suggest that HTLV-1 promotes cellular proliferation and tumor formation of ATL cells by modulating Notch signaling via a posttranslational mechanism that involves interactions between Tax, NICD, and RBP-jκ.


Assuntos
Infecções por HTLV-I/complicações , Vírus Linfotrópico T Tipo 1 Humano/fisiologia , Leucemia-Linfoma de Células T do Adulto/metabolismo , Leucemia-Linfoma de Células T do Adulto/virologia , Receptor Notch1/metabolismo , Adulto , Proliferação de Células , Infecções por HTLV-I/metabolismo , Interações Hospedeiro-Patógeno , Humanos , Células Jurkat , Leucemia-Linfoma de Células T do Adulto/patologia , Transdução de Sinais
19.
J Virol ; 92(24)2018 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-30258009

RESUMO

Adult T-cell leukemia (ATL) is a highly aggressive T-cell malignancy induced by human T-cell leukemia virus type 1 (HTLV-1) infection. Long noncoding RNA (lncRNA) plays a critical role in the development and progression of multiple human cancers. However, the function of lncRNA in HTLV-1-induced oncogenesis has not been elucidated. In the present study, we show that the expression level of the lncRNA ANRIL was elevated in HTLV-1-infected cell lines and clinical ATL samples. E2F1 induced ANRIL transcription by enhancing its promoter activity. Knockdown of ANRIL in ATL cells repressed cellular proliferation and increased apoptosis in vitro and in vivo As a mechanism for these actions, we found that ANRIL targeted EZH2 and activated the NF-κB pathway in ATL cells. This activation was independent of the histone methyltransferase (HMT) activity of EZH2 but required the formation of an ANRIL/EZH2/p65 ternary complex. A chromatin immunoprecipitation assay revealed that ANRIL/EZH2 enhanced p65 DNA binding capability. In addition, we observed that the ANRIL/EZH2 complex repressed p21/CDKN1A transcription through H3K27 trimethylation of the p21/CDKN1A promoter. Taken together, our results implicate that the lncRNA ANRIL, by cooperating with EZH2, supports the proliferation of HTLV-1-infected cells, which is thought to be critical for oncogenesis.IMPORTANCE Human T-cell leukemia virus type 1 (HTLV-1) is the pathogen that causes adult T-cell leukemia (ATL), which is a unique malignancy of CD4+ T cells. A role for long noncoding RNA (lncRNA) in HTLV-1-mediated cellular transformation has not been described. In this study, we demonstrated that the lncRNA ANRIL was important for maintaining the proliferation of ATL cells in vitro and in vivo ANRIL was shown to activate NF-κB signaling through forming a ternary complex with EZH2 and p65. Furthermore, epigenetic inactivation of p21/CDKN1A was involved in the oncogenic function of ANRIL. To the best of our knowledge, this is the first study to address the regulatory role of the lncRNA ANRIL in ATL and provides an important clue to prevent or treat HTLV-1-associated human diseases.


Assuntos
Fator de Transcrição E2F1/metabolismo , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Leucemia-Linfoma de Células T do Adulto/patologia , RNA Longo não Codificante/genética , Adulto , Idoso , Animais , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Células Jurkat , Leucemia-Linfoma de Células T do Adulto/genética , Leucemia-Linfoma de Células T do Adulto/metabolismo , Masculino , Camundongos , Pessoa de Meia-Idade , NF-kappa B/metabolismo , Transplante de Neoplasias , Transdução de Sinais , Regulação para Cima
20.
Magn Reson Med ; 81(5): 2947-2958, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30615208

RESUMO

PURPOSE: To develop a flexible method for tracking respiratory and cardiac motions throughout MR and PET-MR body examinations that requires no additional hardware and minimal sequence modification. METHODS: The incorporation of a contrast-neutral rosette navigator module following the RF excitation allows for robust cardiorespiratory motion tracking with minimal impact on the host sequence. Spatial encoding gradients are applied to the FID signal and the desired motion signals are extracted with a blind source separation technique. This approach is validated with an anthropomorphic, PET-MR-compatible motion phantom as well as in 13 human subjects. RESULTS: Both respiratory and cardiac motions were reliably extracted from the proposed rosette navigator in phantom and patient studies. In the phantom study, the MR-derived motion signals were additionally validated against the ground truth measurement of diaphragm displacement and left ventricle model triggering pulse. CONCLUSION: The proposed method yields accurate respiratory and cardiac motion-state tracking, requiring only a short (1.76 ms) additional navigator module, which is self-refocusing and imposes minimal constraints on sequence design.


Assuntos
Coração/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética , Movimento (Física) , Tomografia por Emissão de Pósitrons , Antropometria , Humanos , Modelos Cardiovasculares , Imagens de Fantasmas , Respiração
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