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1.
EMBO Rep ; 22(12): e51503, 2021 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-34585824

RESUMO

ß-Catenin is a multifunctional protein and participates in numerous processes required for embryonic development, cell proliferation, and homeostasis through various molecular interactions and signaling pathways. To date, however, there is no direct evidence that ß-catenin contributes to cytokinesis. Here, we identify a novel p-S60 epitope on ß-catenin generated by Plk1 kinase activity, which can be found at the actomyosin contractile ring of early telophase cells and at the midbody of late telophase cells. Depletion of ß-catenin leads to cytokinesis-defective phenotypes, which eventually result in apoptotic cell death. In addition, phosphorylation of ß-catenin Ser60 by Plk1 is essential for the recruitment of Ect2 to the midbody, activation of RhoA, and interaction between ß-catenin, Plk1, and Ect2. Time-lapse image analysis confirmed the importance of ß-catenin phospho-Ser60 in furrow ingression and the completion of cytokinesis. Taken together, we propose that phosphorylation of ß-catenin Ser60 by Plk1 in cooperation with Ect2 is essential for the completion of cytokinesis. These findings may provide fundamental knowledge for the research of cytokinesis failure-derived human diseases.


Assuntos
Actomiosina , Citocinese , Actomiosina/metabolismo , Proteínas de Ciclo Celular/metabolismo , Células HeLa , Humanos , Fosforilação , Proteínas Serina-Treonina Quinases , Proteínas Proto-Oncogênicas/metabolismo , Fuso Acromático/metabolismo , beta Catenina/metabolismo , Quinase 1 Polo-Like
2.
Biochem Biophys Res Commun ; 635: 1-11, 2022 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-36252331

RESUMO

Primary cilia, antenna-like cellular sensor structures, are generated from the mother centriole in the G0/G1 cell-cycle phase under control by cellular signaling pathways involving Wnt, hedgehog, and platelet-derived growth factor. Although primary ciliary dynamics have been reported to be closely related to ciliopathy and tumorigenesis, the molecular basis for the role of primary cilia in human disease is lacking. To clarify how Wnt3a affects primary ciliogenesis in anticancer drug-resistant cells, we derived specific drug-resistant subcell lines from A549 human lung cancer cells using anticancer drugs doxorubicin, dasatinib, and paclitaxel (A549/Dox, A549/Das, and A549/Pac, respectively). The primary cilia-containing cell population and primary cilia length increased in the A549/Dox and A549/Pac subcell lines under increased MDR1 expression, when compared to those in the parental A549 cells. In the A549/Das subcell line, primary cilia length increased but the cell population was not affected. In addition, Wnt3a increased primary cilia-containing cell population and primary cilia length in A549/Dox, A549/Das, and A549/Pac cells, without change of cell growth. Abnormal shapes of primary cilia were frequently observed by anticancer drug resistance and Wnt3a stimulation. Taken together, our results indicate that anticancer drug resistance and Wnt3a affect primary ciliogenesis synergistically, suggesting a potential new strategy for overcoming anticancer drug resistance.


Assuntos
Antineoplásicos , Neoplasias Pulmonares , Humanos , Células A549 , Antineoplásicos/uso terapêutico , Doxorrubicina/uso terapêutico , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , Paclitaxel/uso terapêutico , Cílios/metabolismo , Proteína Wnt3A/metabolismo
3.
Int J Mol Sci ; 22(14)2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-34299191

RESUMO

Primary cilia are nonmotile cellular signal-sensing antenna-like structures composed of microtubule-based structures that distinguish them from motile cilia in structure and function. Primary ciliogenesis is regulated by various cellular signals, such as Wnt, hedgehog (Hh), and platelet-derived growth factor (PDGF). The abnormal regulation of ciliogenesis is closely related to developing various human diseases, including ciliopathies and cancer. This study identified a novel primary ciliogenesis factor Cullin 1 (CUL1), a core component of Skp1-Cullin-F-box (SCF) E3 ubiquitin ligase complex, which regulates the proteolysis of dishevelled 2 (Dvl2) through the ubiquitin-proteasome system. Through immunoprecipitation-tandem mass spectrometry analysis, 176 Dvl2 interacting candidates were identified, of which CUL1 is a novel Dvl2 modulator that induces Dvl2 ubiquitination-dependent degradation. Neddylation-dependent CUL1 activity at the centrosomes was essential for centrosomal Dvl2 degradation and primary ciliogenesis. Therefore, this study provides a new mechanism of Dvl2 degradation by CUL1, which ultimately leads to primary ciliogenesis, and suggest a novel target for primary cilia-related human diseases.


Assuntos
Cílios/fisiologia , Proteínas Culina/metabolismo , Proteínas Desgrenhadas/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteínas Ligases SKP Culina F-Box/metabolismo , Ubiquitina/metabolismo , Células Cultivadas , Humanos , Ligação Proteica , Proteólise , Transdução de Sinais , Ubiquitinação
4.
Int J Mol Sci ; 21(13)2020 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-32645923

RESUMO

In the past, several microtubule targeting agents (MTAs) have been developed into successful anticancer drugs. However, the usage of these drugs has been limited by the acquisition of drug resistance in many cancers. Therefore, there is a constant demand for the development of new therapeutic drugs. Here we report the discovery of 5-5 (3-cchlorophenyl)-N-(3-pyridinyl)-2-furamide (CPPF), a novel microtubule targeting anticancer agent. Using both 2D and 3D culture systems, we showed that CPPF was able to suppress the proliferation of diverse cancer cell lines. In addition, CPPF was able to inhibit the growth of multidrug-resistant cell lines that are resistant to other MTAs, such as paclitaxel and colchicine. Our results showed that CPPF inhibited growth by depolymerizing microtubules leading to mitotic arrest and apoptosis. We also confirmed CPPF anticancer effects in vivo using both a mouse xenograft and a two-step skin cancer mouse model. Using established zebrafish models, we showed that CPPF has low toxicity in vivo. Overall, our study proves that CPPF has the potential to become a successful anticancer chemotherapeutic drug.


Assuntos
Antineoplásicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Microtúbulos/metabolismo , Neoplasias/tratamento farmacológico , Células A549 , Animais , Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Colchicina/farmacologia , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Células HeLa , Células Hep G2 , Humanos , Células Jurkat , Células K562 , Células MCF-7 , Masculino , Camundongos , Mitose/efeitos dos fármacos , Neoplasias/metabolismo , Células PC-3 , Paclitaxel/farmacologia , Células U937 , Ensaios Antitumorais Modelo de Xenoenxerto/métodos , Peixe-Zebra
5.
J Biol Chem ; 293(3): 847-862, 2018 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-29191835

RESUMO

Elevated expression of human enhancer filamentation 1 (HEF1; also known as NEDD9 or Cas-L) is an essential stimulus for the metastatic process of various solid tumors. This process requires HEF1 localization to focal adhesions (FAs). Although the association of HEF1 with FAs is considered to play a role in cancer cell migration, the mechanism targeting HEF1 to FAs remains unclear. Moreover, up-regulation of Polo-like kinase 1 (Plk1) positively correlates with human cancer metastasis, yet how Plk1 deregulation promotes metastasis remains elusive. Here, we report that casein kinase 1δ (CK1δ) phosphorylates HEF1 at Ser-780 and Thr-804 and that these phosphorylation events promote a physical interaction between Plk1 and HEF1. We found that this interaction is critical for HEF1 translocation to FAs and for inducing migration of HeLa cells. Plk1-docking phosphoepitopes were mapped/confirmed in HEF1 by various methods, including X-ray crystallography, and mutated for functional analysis in HeLa cells. In summary, our results reveal the role of a phosphorylation-dependent HEF1-Plk1 complex in HEF1 translocation to FAs to induce cell migration. Our findings provide critical mechanistic insights into the HEF1-Plk1 complex-dependent localization of HEF1 to FAs underlying the metastatic process and may therefore contribute to the development of new cancer therapies.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas de Ciclo Celular/metabolismo , Adesões Focais/metabolismo , Fosfoproteínas/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas de Ciclo Celular/genética , Linhagem Celular , Proliferação de Células/genética , Proliferação de Células/fisiologia , Adesões Focais/genética , Células HeLa , Humanos , Immunoblotting , Imunoprecipitação , Fosfoproteínas/genética , Fosforilação/genética , Fosforilação/fisiologia , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas/genética , Quinase 1 Polo-Like
6.
Biochim Biophys Acta ; 1862(6): 1228-35, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26912411

RESUMO

HIV protease inhibitors are key components of HIV antiretroviral therapies, which are fundamental in the treatment of HIV infection. However, the protease inhibitors are well-known to induce metabolic dysfunction which can in turn escalate the complications of HIV, including HIV associated neurocognitive disorders. As experimental and epidemiological data support a therapeutic role for adiponectin in both metabolic and neurologic homeostasis, this study was designed to determine if increased adiponectin could prevent the detrimental effects of protease inhibitors in mice. Adult male wild type (WT) and adiponectin-overexpressing (ADTg) mice were thus subjected to a 4-week regimen of lopinavir/ritonavir, followed by comprehensive metabolic, neurobehavioral, and neurochemical analyses. Data show that lopinavir/ritonavir-induced lipodystrophy, hypoadiponectinemia, hyperglycemia, hyperinsulinemia, and hypertriglyceridemia were attenuated in ADTg mice. Furthermore, cognitive function and blood-brain barrier integrity were preserved, while loss of cerebrovascular markers and white matter injury were prevented in ADTg mice. Finally, lopinavir/ritonavir caused significant increases in expression of markers of brain inflammation and decreases in synaptic markers in WT, but not in ADTg mice. Collectively, these data reinforce the pathophysiologic link from metabolic dysfunction to loss of cerebrovascular and cognitive homeostasis; and suggest that preservation and/or replacement of adiponectin could prevent these key aspects of HIV protease inhibitor-induced toxicity in clinical settings.


Assuntos
Adiponectina/metabolismo , Lesões Encefálicas/induzido quimicamente , Encéfalo/irrigação sanguínea , Inibidores da Protease de HIV/efeitos adversos , Lopinavir/efeitos adversos , Ritonavir/efeitos adversos , Adiponectina/genética , Animais , Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/metabolismo , Barreira Hematoencefálica/patologia , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Lesões Encefálicas/metabolismo , Lesões Encefálicas/patologia , Cognição/efeitos dos fármacos , Infecções por HIV/tratamento farmacológico , Homeostase/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Regulação para Cima
7.
J Biol Chem ; 288(36): 25924-25937, 2013 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-23888052

RESUMO

Chrysin (5,7-dihydroxyflavone), a natural flavonoid widely distributed in plants, reportedly has chemopreventive properties against various cancers. However, the anticancer activity of chrysin observed in in vivo studies has been disappointing. Here, we report that a chrysin derivative, referred to as compound 69407, more strongly inhibited EGF-induced neoplastic transformation of JB6 P(+) cells compared with chrysin. It attenuated cell cycle progression of EGF-stimulated cells at the G1 phase and inhibited the G1/S transition. It caused loss of retinoblastoma phosphorylation at both Ser-795 and Ser-807/811, the preferred sites phosphorylated by Cdk4/6 and Cdk2, respectively. It also suppressed anchorage-dependent and -independent growth of A431 human epidermoid carcinoma cells. Compound 69407 reduced tumor growth in the A431 mouse xenograft model and retinoblastoma phosphorylation at Ser-795 and Ser-807/811. Immunoprecipitation kinase assay results showed that compound 69407 attenuated endogenous Cdk4 and Cdk2 kinase activities in EGF-stimulated JB6 P(+) cells. Pulldown and in vitro kinase assay results indicated that compound 69407 directly binds with Cdk2 and Cdk4 in an ATP-independent manner and inhibited their kinase activities. A binding model between compound 69407 and a crystal structure of Cdk2 predicted that compound 69407 was located inside the Cdk2 allosteric binding site. The binding was further verified by a point mutation binding assay. Overall results indicated that compound 69407 is an ATP-noncompetitive cyclin-dependent kinase inhibitor with anti-tumor effects, which acts by binding inside the Cdk2 allosteric pocket. This study provides new insights for creating a general pharmacophore model to design and develop novel ATP-noncompetitive agents with chemopreventive or chemotherapeutic potency.


Assuntos
Carcinoma de Células Escamosas/tratamento farmacológico , Quinases Ciclina-Dependentes/antagonistas & inibidores , Flavonoides/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Neoplasias Cutâneas/tratamento farmacológico , Regulação Alostérica/efeitos dos fármacos , Animais , Sítios de Ligação , Carcinoma de Células Escamosas/enzimologia , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Cristalografia por Raios X , Quinases Ciclina-Dependentes/genética , Quinases Ciclina-Dependentes/metabolismo , Fator de Crescimento Epidérmico/genética , Fator de Crescimento Epidérmico/metabolismo , Flavonoides/química , Fase G1/efeitos dos fármacos , Fase G1/genética , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Modelos Moleculares , Transplante de Neoplasias , Inibidores de Proteínas Quinases/química , Proteína do Retinoblastoma/genética , Proteína do Retinoblastoma/metabolismo , Fase S/efeitos dos fármacos , Fase S/genética , Neoplasias Cutâneas/enzimologia , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/patologia
8.
Biochim Biophys Acta ; 1832(9): 1456-62, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23313575

RESUMO

Cerebral amyloid angiopathy (CAA) occurs in nearly every individual with Alzheimer's disease (AD) and Down's syndrome, and is the second largest cause of intracerebral hemorrhage. Mouse models of CAA have demonstrated evidence for increased gliosis contributing to CAA pathology. Nearly two thirds of Americans are overweight or obese, with little known about the effects of obesity on the brain, although increasingly the vasculature appears to be a principle target of obesity effects on the brain. In the current study we describe for the first time whether diet induced obesity (DIO) modulates glial reactivity, amyloid levels, and inflammatory signaling in a mouse model of CAA. In these studies we identify surprisingly that DIO does not significantly increase Aß levels, astrocyte (GFAP) or microglial (IBA-1) gliosis in the CAA mice. However, within the hippocampal gyri a localized increase in reactive microglia were increased in the CA1 and stratum oriens relative to CAA mice on a control diet. DIO was observed to selectively increase IL-6 in CAA mice, with IL-1ß and TNF-α not increased in CAA mice in response to DIO. Taken together, these data show that prolonged DIO has only modest effects towards Aß in a mouse model of CAA, but appears to elevate some localized microglial reactivity within the hippocampal gyri and selective markers of inflammatory signaling. These data are consistent with the majority of the existing literature in other models of Aß pathology, which surprisingly show a mixed profile of DIO effects towards pathological processes in mouse models of neurodegenerative disease. The importance for considering the potential impact of ceiling effects in pathology within mouse models of Aß pathogenesis, and the current experimental limitations for DIO in mice to fully replicate metabolic dysfunction present in human obesity, are discussed. This article is part of a Special Issue entitled: Animal Models of Disease.


Assuntos
Doença de Alzheimer/complicações , Encéfalo/patologia , Angiopatia Amiloide Cerebral/etiologia , Dieta/efeitos adversos , Modelos Animais de Doenças , Gliose/etiologia , Obesidade/etiologia , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/genética , Peptídeos beta-Amiloides/metabolismo , Animais , Western Blotting , Encéfalo/metabolismo , Angiopatia Amiloide Cerebral/patologia , Feminino , Gliose/patologia , Humanos , Técnicas Imunoenzimáticas , Interleucina-6/genética , Interleucina-6/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microglia/patologia , Obesidade/patologia , Placa Amiloide/patologia , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo
9.
Eur Radiol ; 24(6): 1410-20, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24647823

RESUMO

OBJECTIVES: To investigate the diagnostic performance of 15-min delayed contrast-enhanced computed tomography (15-DECT) compared with that of chemical shift magnetic resonance (CSMR) imaging in differentiating hyperattenuating adrenal masses and to perform subgroup analysis in underlying malignancy and non-malignancy. METHODS: This study included 478 adrenal masses in 453 patients examined with 15-DECT and 235 masses in 217 patients examined with CSMR. Relative percentage washout (RPW) and absolute percentage washout (APW) on 15-DECT, and signal intensity index (SII) and adrenal-to-spleen ratio (ASR) on CSMR were measured. Sensitivity, specificity and accuracy of 15-DECT and CSMR were analysed for characterisation of adrenal adenoma. Subgroup analyses were performed in patients with and without underlying malignancy. Attenuation and size of the masses on unenhanced CT correlated with the risk of non-adenoma. RESULTS: RPW calculated from 15-DECT showed the highest diagnostic performance for characterising hyperattenuating adrenal masses regardless of underlying malignancy, and the sensitivity, specificity and accuracy were 91.7 %, 74.8 % and 88.1 %, respectively in all patients. The risk of non-adenoma increased approximately threefold as mass size increased 1 cm or as its attenuation value increased by 10 Hounsfield units. CONCLUSIONS: 15-DECT was more accurate than CSMR in characterising hyperattenuating adrenal masses regardless of underlying malignancy. KEY POINTS: Delayed contrast-enhanced CT and chemical shift magnetic resonance (CSMR) characterise adrenal lesions. 15-min DECT is more accurate than CSMR in characterising hyperattenuating adrenal masses. Sensitivity of CSMR decreases as the CT attenuation of adenomas increases. Risk of non-adenoma is increased 2.9-fold as size increased by 1 cm. Risk of non-adenoma is increased 2.9-fold as attenuation increased by 10 HU.


Assuntos
Adenoma/diagnóstico por imagem , Adenoma/patologia , Neoplasias das Glândulas Suprarrenais/diagnóstico por imagem , Neoplasias das Glândulas Suprarrenais/patologia , Imageamento por Ressonância Magnética/métodos , Tomografia Computadorizada por Raios X/métodos , Doenças das Glândulas Suprarrenais/diagnóstico por imagem , Doenças das Glândulas Suprarrenais/patologia , Adenoma Adrenocortical/diagnóstico por imagem , Adenoma Adrenocortical/patologia , Adulto , Idoso , Carcinoma de Células Renais/diagnóstico por imagem , Carcinoma de Células Renais/patologia , Meios de Contraste , Feminino , Humanos , Neoplasias Renais/diagnóstico por imagem , Neoplasias Renais/patologia , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Feocromocitoma/diagnóstico por imagem , Feocromocitoma/patologia , Estudos Retrospectivos , Sensibilidade e Especificidade , Fatores de Tempo
10.
Bioorg Med Chem Lett ; 24(7): 1802-4, 2014 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-24613164

RESUMO

Three new pyrrolobenzodiazepine derivatives, boseongazepines A-C (1-3), were isolated from a culture broth of Streptomyces sp. 11A057, together with the known compound usabamycin B (4). The structures of 1-4 were determined through the analysis of spectroscopic data including extensive 1D-, 2D-NMR, and MS techniques. Cell growth inhibition effects of these compounds were evaluated against Jurkat, K-562, HL-60, and HepG2 cell lines.


Assuntos
Antineoplásicos/farmacologia , Benzodiazepinas/farmacologia , Benzodiazepinonas/farmacologia , Pirróis/farmacologia , Streptomyces/química , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Benzodiazepinas/química , Benzodiazepinas/isolamento & purificação , Benzodiazepinonas/química , Benzodiazepinonas/isolamento & purificação , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Células HL-60 , Células Hep G2 , Humanos , Células Jurkat , Células K562 , Conformação Molecular , Pirróis/química , Pirróis/isolamento & purificação , Relação Estrutura-Atividade
11.
J Nat Prod ; 77(4): 744-50, 2014 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-24597820

RESUMO

The secondary metabolites illudins C2 (1) and C3 (2), obtained from the culture broth of Coprinus atramentarius, have been shown to possess antimicrobial activity. In the present study, we discovered novel biological activities of 1 and 2 in lipolysis of differentiated 3T3-L1 adipocytes and adipogenesis of 3T3-L1 preadipocytes. Compounds 1 and 2 exhibit a dose-dependent increase in glycerol release and thereby reduce intracellular lipid accumulation. The stimulatory effects of 1 and 2 on lipolysis are prevented by cAMP-dependent protein kinase (PKA) and extracellular signal-regulated kinase (ERK) inhibitors. Compounds 1 and 2 down-regulated perilipin and also affected the mRNA and protein levels of adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL). However, 1 and 2 treatment leads to a significant increase in PKA-mediated phosphorylation of HSL at S563 and S660. In addition, 1 and 2 treatment in 3T3-L1 preadipocytes induces down-regulation of the critical transcription factors, CCAAT/enhancer binding protein α and ß (C/EBPα and C/EBPß), and peroxisome proliferator activated receptor γ (PPARγ), which are required for adipogenesis, and accordingly inhibits adipogenesis. These results suggest that 1 and 2 might be useful for treating obesity due to their modulatory effects on fat by affecting adipocyte differentiation and fat mobilization.


Assuntos
Adipócitos/efeitos dos fármacos , Adipogenia/efeitos dos fármacos , Proteína beta Intensificadora de Ligação a CCAAT/efeitos dos fármacos , Coprinus/química , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Lipase/metabolismo , Lipólise/efeitos dos fármacos , PPAR gama/metabolismo , Sesquiterpenos/isolamento & purificação , Sesquiterpenos/farmacologia , Células 3T3-L1 , Adipócitos/metabolismo , Adipogenia/fisiologia , Animais , Proteína alfa Estimuladora de Ligação a CCAAT , Relação Dose-Resposta a Droga , Glicerol/análise , Glicerol/metabolismo , Lipase/análise , Lipólise/fisiologia , Camundongos , Estrutura Molecular , Obesidade/tratamento farmacológico , Sesquiterpenos Policíclicos , Sesquiterpenos/química
12.
IEEE Trans Pattern Anal Mach Intell ; 45(5): 6372-6385, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36112555

RESUMO

Stereo confidence estimation aims to estimate the reliability of the estimated disparity by stereo matching. Different from the previous methods that exploit the limited input modality, we present a novel method that estimates confidence map of an initial disparity by making full use of tri-modal input, including matching cost, disparity, and color image through deep networks. The proposed network, termed as Locally Adaptive Fusion Networks (LAF-Net), learns locally-varying attention and scale maps to fuse the tri-modal confidence features. Moreover, we propose a knowledge distillation framework to learn more compact confidence estimation networks as student networks. By transferring the knowledge from LAF-Net as teacher networks, the student networks that solely take as input a disparity can achieve comparable performance. To transfer more informative knowledge, we also propose a module to learn the locally-varying temperature in a softmax function. We further extend this framework to a multiview scenario. Experimental results show that LAF-Net and its variations outperform the state-of-the-art stereo confidence methods on various benchmarks.

13.
Nanoscale Horiz ; 8(10): 1345-1365, 2023 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-37608742

RESUMO

The integration of two-dimensional (2D) van der Waals materials with nanostructures has triggered a wide spectrum of optical and optoelectronic applications. Photonic structures of conventional materials typically lack efficient reconfigurability or multifunctionality. Atomically thin 2D materials can thus generate new functionality and reconfigurability for a well-established library of photonic structures such as integrated waveguides, optical fibers, photonic crystals, and metasurfaces, to name a few. Meanwhile, the interaction between light and van der Waals materials can be drastically enhanced as well by leveraging micro-cavities or resonators with high optical confinement. The unique van der Waals surfaces of the 2D materials enable handiness in transfer and mixing with various prefabricated photonic templates with high degrees of freedom, functionalizing as the optical gain, modulation, sensing, or plasmonic media for diverse applications. Here, we review recent advances in synergizing 2D materials to nanophotonic structures for prototyping novel functionality or performance enhancements. Challenges in scalable 2D materials preparations and transfer, as well as emerging opportunities in integrating van der Waals building blocks beyond 2D materials are also discussed.

14.
J Sci Food Agric ; 92(15): 2975-82, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22522592

RESUMO

BACKGROUND: The conventional method of processing ginseng (Panax ginseng) roots into red ginseng involves mainly heating and drying processes. In the present study, this method was modified by using high hydrostatic pressure (HHP) to improve the physicochemical characteristics of red ginseng. RESULTS: The HHP process (600 MPa for 1 min) significantly improved the histological properties of red ginseng by increasing cellular disruption and release of cell contents. The total reducing sugar content was significantly (P < 0.05) higher (increased from 10.67 to 15.25 mg g(-1)) in red ginseng processed at 600 MPa for 1 min. Similarly, the total free amino acid content also increased significantly (from 2.81 to 7.77 mg g(-1)). The HHP process resulted in superior and more even colouration and gave an attractive visual appearance to red ginseng. The optical density at 420 nm and Hunter's colour a value (redness) of extracts prepared from red ginseng increased significantly (P < 0.05) with the application of HHP. CONCLUSION: HHP-processed red ginseng has significantly higher reducing sugar and free amino acid contents together with a more compact cell structure and superior visual quality (brighter red colour). Hence the application of HHP in red ginseng processing can result in ginseng products of improved quality compared with those obtained by the conventional method.


Assuntos
Cor , Manipulação de Alimentos/métodos , Panax , Raízes de Plantas/química , Raízes de Plantas/ultraestrutura , Aminoácidos/análise , Carboidratos/análise , Dessecação , Temperatura Alta , Pressão Hidrostática , Reação de Maillard , Microscopia Eletrônica de Varredura
15.
IEEE Trans Pattern Anal Mach Intell ; 44(9): 5293-5313, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33798066

RESUMO

Stereo matching is one of the most popular techniques to estimate dense depth maps by finding the disparity between matching pixels on two, synchronized and rectified images. Alongside with the development of more accurate algorithms, the research community focused on finding good strategies to estimate the reliability, i.e., the confidence, of estimated disparity maps. This information proves to be a powerful cue to naively find wrong matches as well as to improve the overall effectiveness of a variety of stereo algorithms according to different strategies. In this paper, we review more than ten years of developments in the field of confidence estimation for stereo matching. We extensively discuss and evaluate existing confidence measures and their variants, from hand-crafted ones to the most recent, state-of-the-art learning based methods. We study the different behaviors of each measure when applied to a pool of different stereo algorithms and, for the first time in literature, when paired with a state-of-the-art deep stereo network. Our experiments, carried out on five different standard datasets, provide a comprehensive overview of the field, highlighting in particular both strengths and limitations of learning-based strategies.

16.
J Am Chem Soc ; 133(18): 6865-7, 2011 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-21500849

RESUMO

An acinar morphogenesis inhibitor named fusarisetin A (1) that possesses both an unprecedented carbon skeleton and a new pentacyclic ring system has been identified from an in-house fractionated fungal library using a three-dimensional matrigel-induced acinar morphogenesis assay system. The structure of 1 was determined in detail by NMR and circular dichroism spectroscopy, X-ray analysis, and chemical reaction experiments.


Assuntos
Antineoplásicos/farmacologia , Carcinoma de Células Acinares/patologia , Movimento Celular/efeitos dos fármacos , Depsipeptídeos/farmacologia , Fusarium/química , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Linhagem Celular Tumoral , Dicroísmo Circular , Cristalografia por Raios X , Depsipeptídeos/química , Humanos , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Invasividade Neoplásica
17.
Genes Genomics ; 43(5): 567-575, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33826094

RESUMO

BACKGROUND: Upregulation of human enhancer filamentation 1 (HEF1/NEDD9/Cas-L) and Polo-like kinase 1 (Plk1) is closely correlated with metastasis of human cancer. However, the mechanism by which the overexpression of HEF1 or Plk1 stimulates cancer metastasis and induces tumorigenesis remains enigmatic. In addition, the accumulation of HEF1 at the focal adhesion (FA) is known to be an essential event in cancer cell migration, but the mechanism of how HEF1 is targeted to the FA remains yet to be unveiled. OBJECTIVE: This study was performed to elucidate the FA docking mechanism of HEF1 and to determine its effect on tumorigenesis. METHODS: To confirm the effect of the kinase on HEF1 translocation, various expression-knockdown stable cell lines were generated using a lentivirus system, and the effect of the HEF1-Plk1 complex on tumorigenesis was confirmed using a xenograft mouse model. RESULTS: Here, we show that Wnt5a-dependent Plk1 binding to HEF1 is critically required for HEF1 translocation to the FA. We also confirmed that Plk1 and CK1δ activities essential for HEF1 translocation are induced by Wnt5a. Finally, we confirmed the induction of tumorigenesis by the HEF1-Plk1 complex in the xenograft mouse model. CONCLUSION: Our data collectively unveil the Wnt5a-CK1δ-HEF1-Plk1-FA remodeling pathway that governs HEF1 transportation to the FA to induce cell migration and tumorigenesis. This study sheds light on a mechanism underlying tumorigenesis and provides new strategies for anticancer therapy.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Carcinogênese/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteína Wnt-5a/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Carcinogênese/genética , Proteínas de Ciclo Celular/genética , Movimento Celular , Células HEK293 , Células HeLa , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas/genética , Proteína Wnt-5a/genética , Quinase 1 Polo-Like
18.
J Microbiol Biotechnol ; 30(1): 31-37, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-31752054

RESUMO

We previously identified a new heparinase inhibitor fungal metabolite, named CRM646-A, which showed inhibition of heparinase and telomerase activities in an in vitro enzyme assay and antimetastatic activity in a cell-based assay. In this study, we elucidated the mechanism by which CRM646-A rapidly induced nucleus condensation, plasma membrane disruption and morphological changes by increasing intracellular Ca2+ levels. Furthermore, PD98059, a mitogen-activated protein kinase (MEK) inhibitor, inhibited CRM646-A-induced nucleus condensation through ERK1/2 activation in rat 3Y1 fibroblast cells. We identified CRM646-A as a Ca2+ ionophore-like agent with a distinctly different chemical structure from that of previously reported Ca2+ ionophores. These results indicate that CRM646-A has the potential to be used as a new and effective antimetastatic drug.


Assuntos
Cálcio/metabolismo , Núcleo Celular/metabolismo , Fibroblastos/efeitos dos fármacos , Hidroxibenzoatos/farmacologia , Animais , Linhagem Celular , Ativação Enzimática , Inibidores Enzimáticos/farmacologia , Fibroblastos/metabolismo , Fungos/química , Heparina Liase/antagonistas & inibidores , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Ratos , Transdução de Sinais
19.
Cell Rep ; 30(5): 1447-1462.e5, 2020 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-32023461

RESUMO

Primary cilium is an antenna-like microtubule-based cellular sensing structure. Abnormal regulation of the dynamic assembly and disassembly cycle of primary cilia is closely related to ciliopathy and cancer. The Wnt signaling pathway plays a major role in embryonic development and tissue homeostasis, and defects in Wnt signaling are associated with a variety of human diseases, including cancer. In this study, we provide direct evidence of Wnt3a-induced primary ciliogenesis, which includes a continuous pathway showing that the stimulation of Wnt3a, a canonical Wnt ligand, promotes the generation of ß-catenin p-S47 epitope by CK1δ, and these events lead to the reorganization of centriolar satellites resulting in primary ciliogenesis. We have also confirmed the application of our findings in MCF-7/ADR cells, a multidrug-resistant tumor cell model. Thus, our data provide a Wnt3a-induced primary ciliogenesis pathway and may provide a clue on how to overcome multidrug resistance in cancer treatment.


Assuntos
Centríolos/metabolismo , Cílios/metabolismo , Organogênese , Proteína Wnt3A/metabolismo , beta Catenina/metabolismo , Sequência de Aminoácidos , Animais , Caseína Quinases/metabolismo , Centrossomo/metabolismo , Resistência a Múltiplos Medicamentos , Resistencia a Medicamentos Antineoplásicos , Epitopos/metabolismo , Células HEK293 , Células HeLa , Humanos , Ligantes , Células MCF-7 , Camundongos , Fosforilação , Fosfosserina/metabolismo , Proteína Wnt3A/química
20.
Sci Rep ; 10(1): 1245, 2020 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-31988303

RESUMO

Fenugreek (Trigonella foenum-graecum) is an annual herbaceous plant and a staple of traditional health remedies for metabolic conditions including high cholesterol and diabetes. While the mechanisms of the beneficial actions of fenugreek remain unknown, a role for intestinal microbiota in metabolic homeostasis is likely. To determine if fenugreek utilizes intestinal bacteria to offset the adverse effects of high fat diets, C57BL/6J mice were fed control/low fat (CD) or high fat (HFD) diets each supplemented with or without 2% (w/w) fenugreek for 16 weeks. The effects of fenugreek and HFD on gut microbiota were comprehensively mapped and then statistically assessed in relation to effects on metrics of body weight, hyperlipidemia, and glucose tolerance. 16S metagenomic analyses revealed robust and significant effects of fenugreek on gut microbiota, with alterations in both alpha and beta diversity as well as taxonomic redistribution under both CD and HFD conditions. As previously reported, fenugreek attenuated HFD-induced hyperlipidemia and stabilized glucose tolerance without affecting body weight. Finally, fenugreek specifically reversed the dysbiotic effects of HFD on numerous taxa in a manner tightly correlated with overall metabolic function. Collectively, these data reinforce the essential link between gut microbiota and metabolic syndrome and suggest that the preservation of healthy populations of gut microbiota participates in the beneficial properties of fenugreek in the context of modern Western-style diets.


Assuntos
Dieta Hiperlipídica/efeitos adversos , Microbioma Gastrointestinal/efeitos dos fármacos , Extratos Vegetais/farmacologia , Animais , Bactérias/genética , Glicemia , Peso Corporal/efeitos dos fármacos , Suplementos Nutricionais , Modelos Animais de Doenças , Dislipidemias/prevenção & controle , Glucose/metabolismo , Intolerância à Glucose/prevenção & controle , Hiperlipidemias/tratamento farmacológico , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/tratamento farmacológico , Obesidade/microbiologia , Extratos Vegetais/metabolismo , RNA Ribossômico 16S/genética , Trigonella/metabolismo
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