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1.
BMC Neurol ; 23(1): 298, 2023 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-37568140

RESUMO

BACKGROUND: Early neurological deterioration (END) sometimes occurs in patients with penetrating artery territory infarction (PATI) and leads to poor prognosis. In this study, we analyzed clinical and neuroimaging characteristics of PATI, and focused on the infarct patterns on diffusion-weighted imaging (DWI). We tried to investigate whether the "island sign" pattern is associated with END. METHODS: We enrolled consecutive patients admitted with acute PATI within 48 h after onset from May 2020 to July 2022. They were divided into with and without the "island sign" pattern on DWI. According to infarct location, all the patients were classified into two groups: the territories of the lenticulostriate arteries (LSA) and paramedian pontine arteries (PPA). The patients in each group were further divided into two groups according to whether they developed END or not. Through analyzing the clinical and neuroimaging characteristics of the patients, we tried to identify the factors that might associated with the "island sign" pattern and the potential predictors of END within the LSA and PPA groups. RESULTS: Out of the 113 patients enrolled in this study, END was found in 17 patients (27.9%) in the LSA group and 20 patients (38.5%) in the PPA group. The "island sign" was found in 26 (23%) patients. In the multivariate analysis, the independent predictors of END in the LSA group were the "island sign" (OR 4.88 95% CI 1.03-23.2 P = 0.045) and high initial National Institute of Health Stroke Scale (NIHSS) (OR 1.79 95% CI 1.08-2.98 P = 0.024) and in the PPA group was the presence of lesions extending to the ventral pontine surface (OR 7.53 95% CI 1.75-32.37 P = 0.007). CONCLUSIONS: The predictive factors for END were different in the LSA and PPA groups. The "island sign" was particularly associated with END in the LSA group.


Assuntos
Imagem de Difusão por Ressonância Magnética , Acidente Vascular Cerebral , Humanos , Estudos Retrospectivos , Imagem de Difusão por Ressonância Magnética/métodos , Artéria Cerebral Média/patologia , Artéria Basilar , Infarto/complicações , Acidente Vascular Cerebral/complicações
2.
J Cell Sci ; 128(17): 3290-303, 2015 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-26220856

RESUMO

Nek2 has been implicated in centrosome disjunction at the onset of mitosis to promote bipolar spindle formation, and hyperactivation of Nek2 leads to the premature centrosome separation. Its activity, therefore, needs to be strictly regulated. In this study, we report that Cep85, an uncharacterized centrosomal protein, acts as a binding partner of Nek2A. It colocalizes with isoform A of Nek2 (Nek2A) at centrosomes and forms a granule meshwork enveloping the proximal ends of centrioles. Opposite to the effects of Nek2A, overexpression of Cep85 in conjunction with inhibition of the motor protein Eg5 (also known as KIF11) leads to the failure of centrosome disjunction. By contrast, depletion of Cep85 results in the precocious centrosome separation. We also define the Nek2A binding and centrosome localization domains within Cep85. Although the Nek2A-binding domain alone is sufficient to inhibit Nek2A kinase activity in vitro, both domains are indispensable for full suppression of centrosome disjunction in cells. Thus, we propose that Cep85 is a bona fide Nek2A-binding partner that surrounds the proximal ends of centrioles where it cooperates with PP1γ (also known as PPP1CC) to antagonize Nek2A activity in order to maintain the centrosome integrity in interphase in mammalian cells.


Assuntos
Centrossomo/metabolismo , Proteínas do Citoesqueleto/metabolismo , Proteínas de Fusão Oncogênica/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Animais , Proteínas do Citoesqueleto/genética , Células HEK293 , Células HeLa , Humanos , Cinesinas/genética , Cinesinas/metabolismo , Camundongos , Células NIH 3T3 , Quinases Relacionadas a NIMA , Proteínas de Fusão Oncogênica/genética , Proteínas Serina-Treonina Quinases/genética , Estrutura Terciária de Proteína
3.
Development ; 141(17): 3410-9, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25139857

RESUMO

Cilia are microtubule-based hair-like organelles that play many important roles in development and physiology, and are implicated in a rapidly expanding spectrum of human diseases, collectively termed ciliopathies. Primary ciliary dyskinesia (PCD), one of the most prevalent of ciliopathies, arises from abnormalities in the differentiation or motility of the motile cilia. Despite their biomedical importance, a methodical functional screen for ciliary genes has not been carried out in any vertebrate at the organismal level. We sought to systematically discover novel motile cilia genes by identifying the genes induced by Foxj1, a winged-helix transcription factor that has an evolutionarily conserved role as the master regulator of motile cilia biogenesis. Unexpectedly, we find that the majority of the Foxj1-induced genes have not been associated with cilia before. To characterize these novel putative ciliary genes, we subjected 50 randomly selected candidates to a systematic functional phenotypic screen in zebrafish embryos. Remarkably, we find that over 60% are required for ciliary differentiation or function, whereas 30% of the proteins encoded by these genes localize to motile cilia. We also show that these genes regulate the proper differentiation and beating of motile cilia. This collection of Foxj1-induced genes will be invaluable for furthering our understanding of ciliary biology, and in the identification of new mutations underlying ciliary disorders in humans.


Assuntos
Cílios/genética , Estudos de Associação Genética , Genômica , Peixe-Zebra/genética , Animais , Cílios/efeitos dos fármacos , Transtornos da Motilidade Ciliar/genética , Embrião não Mamífero/citologia , Embrião não Mamífero/efeitos dos fármacos , Embrião não Mamífero/metabolismo , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Proteínas de Fluorescência Verde/metabolismo , Humanos , Morfolinos/farmacologia , Organogênese/efeitos dos fármacos , Organogênese/genética , Fenótipo , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genética , Peixe-Zebra/embriologia , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo
4.
Zhongguo Zhong Yao Za Zhi ; 42(18): 3564-3571, 2017 Sep.
Artigo em Zh | MEDLINE | ID: mdl-29218943

RESUMO

This study focuses on the protective effect of germacrone on human umbilical vein endothelial cells(HUVECs) damaged by H2O2-induced oxidative stress and its possible mechanisms. The oxidative damage model was established by using 500 µmol•L⁻¹ H2O2 to treat HUVECs for 3 hours, and then protected with different concentrations of germacrone for 24 hours. The effect of germacrone on cell viability of HUVECs damaged by H2O2 was detected by MTT. The contents of PGI2, TXB2, ET-1, t-PA, PAI-1, TNF-α and IL-6 were detected by ELISA. The content of NO was detected by using nitrate reductase method. Colorimetry was used to detect NOS and GSH-Px. The contents of MDA, SOD and LDH were detected by TBA, WST-1 and microplate respectively. Apoptosis was observed by Hoechst 33258 fluorescent staining. The mRNA expressions of Bax, Bcl-2 and Caspase-3 in cells were detected by RT-PCR. The results showed that the cell damage rate was 52% after treated with 500 µmol•L⁻¹ H2O2 for 3 hours. The cell activity was increasing with the rise of germacrone concentration within the range of 20-200 mol•L⁻¹. Compared with normal group, the contents of PGI2, NO, T-NOS, t-PA, SOD, GSH-Px and Bcl-2 mRNA expressions were lower after damaged with H2O2. The contents of PAI-1, ET-1, IL-6, TNF-α, TXB2, LDH, MDA, Bax mRNA and Caspase-3 mRNA expressions were increased. Compared with model group, the contents of PGI2, NO, T-NOS, t-PA, SOD, GSH-Px and Bcl-2 mRNA expressions were increased after treated with germacrone. The contents of PAI-1, ET-1, IL-6, TNF-α, TXB2, LDH, MDA, Bax mRNA and Caspase-3 mRNA expressions were lower after treated with germacrone. According to Hoechst 33258 fluorescence staining, compared with normal group, the cell membrane and the nucleus showed strong dense blue fluorescence, and the number of cells significantly decreased in model group. Compared with model group, blue fluorescence intensity decreased in drug group. The above findings demonstrate that germacrone may improve the effect on HUVECs damaged by H2O2-induced oxidative stress by resisting oxidation and inhibiting cell apoptosis.


Assuntos
Apoptose , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Estresse Oxidativo , Sesquiterpenos de Germacrano/farmacologia , Células Cultivadas , Humanos , Peróxido de Hidrogênio
5.
Development ; 138(3): 487-94, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21205793

RESUMO

Ciliary motility is necessary for many developmental and physiological processes in animals. In zebrafish, motile cilia are thought to be required for the deposition of otoliths, which comprise crystals of protein and calcium carbonate, on hair cells of the inner ear. The identity of the motile cilia and their role in otolith biogenesis, however, remain controversial. Here, we show that the ear vesicle differentiates numerous motile cilia, the spatial distribution of which changes as a function of the expression pattern of the ciliogenic gene foxj1b. By contrast, the hair cells develop immotile kinocilia that serve as static tethers for otolith crystallization. In ears devoid of all cilia, otoliths can form but they are of irregular shapes and sizes and appear to attach instead to the hair cell apical membranes. Moreover, overproduction of motile cilia also disrupts otolith deposition through sustained agitation of the precursor particles. Therefore, the correct spatial and temporal distribution of the motile cilia is crucial for proper otolith formation. Our findings support the view that the hair cells express a binding factor for the otolith precursors, while the motile cilia ensure that the precursors do not sediment prematurely and are efficiently directed towards the hair cells. We also provide evidence that the kinocilia are modified motile cilia that depend on Foxj1b for their differentiation. We propose that in hair cells, a Foxj1b-dependent motile ciliogenic program is altered by the proneural Atoh proteins to promote the differentiation of immotile kinocilia.


Assuntos
Cílios/metabolismo , Orelha Interna/citologia , Células Ciliadas Auditivas/metabolismo , Membrana dos Otólitos/metabolismo , Animais , Animais Geneticamente Modificados , Epigenômica , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Hibridização In Situ , Canais Iônicos , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Microscopia Confocal , Microscopia Eletrônica de Transmissão , Microscopia de Vídeo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Peixe-Zebra , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo
6.
PLoS One ; 19(4): e0300473, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38635663

RESUMO

High-resolution imagery and deep learning models have gained increasing importance in land-use mapping. In recent years, several new deep learning network modeling methods have surfaced. However, there has been a lack of a clear understanding of the performance of these models. In this study, we applied four well-established and robust deep learning models (FCN-8s, SegNet, U-Net, and Swin-UNet) to an open benchmark high-resolution remote sensing dataset to compare their performance in land-use mapping. The results indicate that FCN-8s, SegNet, U-Net, and Swin-UNet achieved overall accuracies of 80.73%, 89.86%, 91.90%, and 96.01%, respectively, on the test set. Furthermore, we assessed the generalization ability of these models using two measures: intersection of union and F1 score, which highlight Swin-UNet's superior robustness compared to the other three models. In summary, our study provides a systematic analysis of the classification differences among these four deep learning models through experiments. It serves as a valuable reference for selecting models in future research, particularly in scenarios such as land-use mapping, urban functional area recognition, and natural resource management.


Assuntos
Aprendizado Profundo , Tecnologia de Sensoriamento Remoto , Benchmarking , Generalização Psicológica , Imagens, Psicoterapia
7.
Comput Methods Programs Biomed ; 254: 108295, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38905987

RESUMO

BACKGROUND AND OBJECTIVE: To evaluate the feasibility and accuracy of radiomics, dosiomics, and deep learning (DL) in predicting Radiation Pneumonitis (RP) in lung cancer patients underwent volumetric modulated arc therapy (VMAT) to improve radiotherapy safety and management. METHODS: Total of 318 and 31 lung cancer patients underwent VMAT from First Affiliated Hospital of Wenzhou Medical University (WMU) and Quzhou Affiliated Hospital of WMU were enrolled for training and external validation, respectively. Models based on radiomics (R), dosiomics (D), and combined radiomics and dosiomics features (R+D) were constructed and validated using three machine learning (ML) methods. DL models trained with CT (DLR), dose distribution (DLD), and combined CT and dose distribution (DL(R+D)) images were constructed. DL features were then extracted from the fully connected layers of the best-performing DL model to combine with features of the ML model with the best performance to construct models of R+DLR, D+DLD, R+D+DL(R+D)) for RP prediction. RESULTS: The R+D model achieved a best area under curve (AUC) of 0.84, 0.73, and 0.73 in the internal validation cohorts with Support Vector Machine (SVM), XGBoost, and Logistic Regression (LR), respectively. The DL(R+D) model achieved a best AUC of 0.89 and 0.86 using ResNet-34 in training and internal validation cohorts, respectively. The R+D+DL(R+D) model achieved a best performance in the external validation cohorts with an AUC, accuracy, sensitivity, and specificity of 0.81(0.62-0.99), 0.81, 0.84, and 0.67, respectively. CONCLUSIONS: The integration of radiomics, dosiomics, and DL features is feasible and accurate for the RP prediction to improve the management of lung cancer patients underwent VMAT.


Assuntos
Aprendizado Profundo , Neoplasias Pulmonares , Pneumonite por Radiação , Radioterapia de Intensidade Modulada , Humanos , Pneumonite por Radiação/diagnóstico por imagem , Pneumonite por Radiação/etiologia , Neoplasias Pulmonares/radioterapia , Neoplasias Pulmonares/diagnóstico por imagem , Masculino , Radioterapia de Intensidade Modulada/métodos , Radioterapia de Intensidade Modulada/efeitos adversos , Feminino , Pessoa de Meia-Idade , Idoso , Tomografia Computadorizada por Raios X , Dosagem Radioterapêutica , Multiômica
8.
Radiother Oncol ; 199: 110438, 2024 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-39013503

RESUMO

PURPOSE: To develop a combined radiomics and deep learning (DL) model in predicting radiation esophagitis (RE) of a grade ≥ 2 for patients with esophageal cancer (EC) underwent volumetric modulated arc therapy (VMAT) based on computed tomography (CT) and radiation dose (RD) distribution images. MATERIALS AND METHODS: A total of 273 EC patients underwent VMAT were retrospectively reviewed and enrolled from two centers and divided into training (n = 152), internal validation (n = 66), and external validation (n = 55) cohorts, respectively. Radiomic and dosiomic features along with DL features using convolutional neural networks were extracted and screened from CT and RD images to predict RE. The performance of these models was evaluated and compared using the area under curve (AUC) of the receiver operating characteristic curves (ROC). RESULTS: There were 5 and 10 radiomic and dosiomic features were screened, respectively. XGBoost achieved a best AUC of 0.703, 0.694 and 0.801, 0.729 with radiomic and dosiomic features in the internal and external validation cohorts, respectively. ResNet34 achieved a best prediction AUC of 0.642, 0.657 and 0.762, 0.737 for radiomics based DL model (DLR) and RD based DL model (DLD) in the internal and external validation cohorts, respectively. Combined model of DLD + Dosiomics + clinical factors achieved a best AUC of 0.913, 0.821 and 0.805 in the training, internal, and external validation cohorts, respectively. CONCLUSION: Although the dose was not responsible for the prediction accuracy, the combination of various feature extraction methods was a factor in improving the RE prediction accuracy. Combining DLD with dosiomic features was promising in the pretreatment prediction of RE for EC patients underwent VMAT.

9.
Radiat Oncol ; 19(1): 72, 2024 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-38851718

RESUMO

BACKGROUND: To integrate radiomics and dosiomics features from multiple regions in the radiation pneumonia (RP grade ≥ 2) prediction for esophageal cancer (EC) patients underwent radiotherapy (RT). METHODS: Total of 143 EC patients in the authors' hospital (training and internal validation: 70%:30%) and 32 EC patients from another hospital (external validation) underwent RT from 2015 to 2022 were retrospectively reviewed and analyzed. Patients were dichotomized as positive (RP+) or negative (RP-) according to CTCAE V5.0. Models with radiomics and dosiomics features extracted from single region of interest (ROI), multiple ROIs and combined models were constructed and evaluated. A nomogram integrating radiomics score (Rad_score), dosiomics score (Dos_score), clinical factors, dose-volume histogram (DVH) factors, and mean lung dose (MLD) was also constructed and validated. RESULTS: Models with Rad_score_Lung&Overlap and Dos_score_Lung&Overlap achieved a better area under curve (AUC) of 0.818 and 0.844 in the external validation in comparison with radiomics and dosiomics models with features extracted from single ROI. Combining four radiomics and dosiomics models using support vector machine (SVM) improved the AUC to 0.854 in the external validation. Nomogram integrating Rad_score, and Dos_score with clinical factors, DVH factors, and MLD further improved the RP prediction AUC to 0.937 and 0.912 in the internal and external validation, respectively. CONCLUSION: CT-based RP prediction model integrating radiomics and dosiomics features from multiple ROIs outperformed those with features from a single ROI with increased reliability for EC patients who underwent RT.


Assuntos
Neoplasias Esofágicas , Nomogramas , Pneumonite por Radiação , Humanos , Neoplasias Esofágicas/radioterapia , Pneumonite por Radiação/etiologia , Feminino , Masculino , Estudos Retrospectivos , Pessoa de Meia-Idade , Idoso , Dosagem Radioterapêutica , Prognóstico , Idoso de 80 Anos ou mais , Tomografia Computadorizada por Raios X , Radiômica
11.
Dev Dyn ; 239(2): 527-34, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20014402

RESUMO

Cilia play important roles in many developmental and physiological processes. However, the genetic and cell biological control of ciliogenesis remains poorly understood. Here, we show that the zebrafish iguana gene is required for differentiation of primary cilia. iguana encodes a zinc finger and coiled-coil containing protein, previously implicated in Hedgehog signaling. We now argue that aberrant Hedgehog activity in iguana -deficient zebrafish arises from their profound lack of primary cilia. By contrast, the requirement of iguana for motile cilia formation is less obligatory. In the absence of iguana function, basal bodies can migrate to the cell surface and appear to engage with the apical membrane. However, formation of ciliary pits and axonemal outgrowth is completely inhibited. Iguana localizes to the base of primary and motile cilia, in the immediate vicinity or closely associated with the basal bodies. These findings identify the Iguana protein as a novel and critical component of ciliogenesis.


Assuntos
Axonema/fisiologia , Proteínas de Transporte/metabolismo , Cílios/fisiologia , Animais , Proteínas Oncogênicas/metabolismo , Transativadores/metabolismo , Peixe-Zebra , Proteína GLI1 em Dedos de Zinco
12.
Genetics ; 180(3): 1445-57, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18791237

RESUMO

Septins are a family of GTP-binding proteins whose heterooligomeric complex is the basic structural element of the septin filaments found in many eukaryotic organisms. In budding yeast, septins are mainly confined at the mother-daughter junction and are required for cell morphogenesis and division. Septins undergo assembly and disassembly in accordance with the progression of the cell cycle. In this report, we identified the yeast protein Syp1p as a new regulator of septin dynamics. Syp1p colocalizes with septins throughout most of the cell cycle. Syp1p interacts with the septin subunit Cdc10p and can be precipitated by Cdc10p and Cdc12p. In the syp1Delta mutant, both formation of a complete septin ring at the incipient bud site and disassembly of the septin ring in later stages of cell division are significantly delayed. In addition, overexpression of Syp1p causes marked acceleration of septin disassembly. The fluorescence recovery after photobleaching (FRAP) assay further showed that Syp1p promotes septin turnover in different cell cycle stages. These results suggest that Syp1p is involved in the regulation of cell cycle-dependent dynamics of the septin cytoskeleton in yeast.


Assuntos
Ciclo Celular/fisiologia , Citoesqueleto/fisiologia , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Divisão Celular , Estruturas Celulares , Proteínas do Citoesqueleto/genética , Proteínas do Citoesqueleto/metabolismo , Recuperação de Fluorescência Após Fotodegradação , GTP Fosfo-Hidrolases/genética , GTP Fosfo-Hidrolases/metabolismo , Regulação Fúngica da Expressão Gênica , Proteínas de Fluorescência Verde/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Schizosaccharomyces/genética , Técnicas do Sistema de Duplo-Híbrido
13.
iScience ; 11: 114-133, 2019 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-30611117

RESUMO

Timely centrosome separation is critical for accurate chromosome separation. It is initiated by Nek2A at the onset of mitosis, but the mechanism for the strict requirement of phosphorylated Nek2A for its own activation remains unclear. In this study, we have found that Plk1 interacts with Cep85 and forms a ternary complex with Cep85-Nek2A. Nek2A binding, but not its kinase activity, is pre-required for Cep85 to be phosphorylated by Plk1. Nek2A-dependent Cep85 phosphorylation, in turn, leads to the dissociation of phosphorylated Cep85 exclusively from phospho-Nek2A, thereby increasing the freed phospho-Nek2A activity. Both kinases are also required for phosphorylating endogenous Cep85 in cells, and timely phosphorylation of Cep85 and Nek2A is crucial for initiating centrosome disjunction at G2/M. Overall, our study has uncovered a previously unrecognized role of Plk1 and Nek2A and identified Cep85 as a missing piece directly relaying Plk1 activity to Nek2A for its activation in centrosome disjunction.

14.
Genetics ; 174(2): 735-52, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16888327

RESUMO

Hedgehog proteins play critical roles in organizing the embryonic development of animals, largely through modulation of target gene expression. Little is currently known, however, about the kinds and numbers of genes whose expression is controlled, directly or indirectly, by Hedgehog activity. Using techniques to globally repress or activate Hedgehog signaling in zebrafish embryos followed by microarray-based expression profiling, we have discovered a cohort of genes whose expression responds significantly to loss or gain of Hedgehog function. We have confirmed the Hedgehog responsiveness of a representative set of these genes with whole-mount in situ hybridization as well as real time PCR. In addition, we show that the consensus Gli-binding motif is enriched within the putative regulatory elements of a sizeable proportion of genes that showed positive regulation in our assay, indicating that their expression is directly induced by Hedgehog. Finally, we provide evidence that the Hedgehog-dependent spatially restricted transcription of one such gene, nkx2.9, is indeed mediated by Gli1 through a single Gli recognition site located within an evolutionarily conserved enhancer fragment. Taken together, this study represents the first comprehensive survey of target genes regulated by the Hedgehog pathway during vertebrate development. Our data also demonstrate for the first time the functionality of the Gli-binding motif in the control of Hedgehog signaling-induced gene expression in the zebrafish embryo.


Assuntos
Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Genoma/fisiologia , Proteínas Hedgehog/fisiologia , Transdução de Sinais/genética , Peixe-Zebra/genética , Animais , Sequência de Bases , Dados de Sequência Molecular , Proteínas Oncogênicas/química , Proteínas Oncogênicas/fisiologia , Transativadores/química , Transativadores/fisiologia , Peixe-Zebra/embriologia , Proteína GLI1 em Dedos de Zinco
15.
Diabetes ; 64(6): 2069-81, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25576055

RESUMO

Leptin, an anorexigenic hormone in the hypothalamus, suppresses food intake and increases energy expenditure. Failure to respond to leptin will lead to obesity. Here, we discovered that nuclear receptor Nur77 expression is lower in the hypothalamus of obese mice compared with normal mice. Injection of leptin results in significant reduction in body weight in wild-type mice but not in Nur77 knockout (KO) littermates or mice with specific Nur77 knockdown in the hypothalamus. Hypothalamic Nur77 not only participates in leptin central control of food intake but also expands leptin's reach to liver and adipose tissues to regulate lipid metabolism. Nur77 facilitates signal transducer and activator of transcription 3 (STAT3) acetylation by recruiting acetylase p300 and disassociating deacetylase histone deacetylase 1 (HDAC1) to enhance the transcriptional activity of STAT3 and consequently modulates the expression of downstream gene Pomc in the hypothalamus. Nur77 deficiency compromises response to leptin in mice fed a high-fat diet. Severe leptin resistance in Nur77 KO mice with increased appetite, lower energy expenditure, and hyperleptinemia contributes to aging-induced obesity. Our study opens a new avenue for regulating metabolism with Nur77 as the positive modulator in the leptin-driven antiobesity in the hypothalamus.


Assuntos
Hipotálamo/metabolismo , Leptina/farmacologia , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/metabolismo , Fator de Transcrição STAT3/metabolismo , Acetilação/efeitos dos fármacos , Animais , Western Blotting , Linhagem Celular , Humanos , Hipotálamo/efeitos dos fármacos , Imunoprecipitação , Metabolismo dos Lipídeos/efeitos dos fármacos , Camundongos , Atividade Motora/efeitos dos fármacos , Obesidade/metabolismo
16.
Int J Clin Exp Pathol ; 6(6): 1076-85, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23696925

RESUMO

UNLABELLED: Hepatitis B virus (HBV) genotype C is associated with the development of hepatocellular carcinoma (HCC). In addition, HBV subgenotype C1 is the major subgenotype in Southern China. The aim of this study was to investigate whether there was the specific mutation patterns in HBV/C1 associated with Southern Chinese patients with HCC. METHODS: Mutations in HBV basal core promoter (BCP) and their association with HCC were assessed in a matched cross-sectional control study of 102 HCC and 105 chronic hepatitis (CH) patients (from Guangdong, China) infected with HBV/C1. Functional analysis of HBx mutants was performed by the colony formation assay and the luciferase assays. RESULTS: T1762/A1764 double mutations was frequently found in patients infected with HBV/C1, regardless of clinical status (64.7% in HCC and 51.4% in CH, P>0.05). Unexpectedly, the adjacent V1753 or A1768 mutation significantly increased the risk of HCC (P<0.05). Moreover, the prevalence of triple or quadruple mutations in BCP was significantly higher in patients with HCC than those with CH, particularly for HBeAg-positive-carriers (P<0.05). Functional analysis revealed that T1762/A1764 mutation alone did not alter the transcriptional activity and the inhibitory effects on cell proliferation of HBx, but triple or quadruple mutations largely abrogated this effect. CONCLUSIONS: Accumulation of mutations involving V1753 or/and A1768 in addition to T1762/A1764 in BCP region were closely related to HCC among the patients infected with HBV/C1, particularly for HBeAg-positive-carriers. The increased risk of HCC caused by BCP variants may be attributable partially to modifying the biological functions of HBx.


Assuntos
Carcinoma Hepatocelular/virologia , Vírus da Hepatite B/genética , Hepatite B/virologia , Neoplasias Hepáticas/virologia , Mutação , Regiões Promotoras Genéticas , Transativadores/genética , Carcinoma Hepatocelular/epidemiologia , Estudos de Casos e Controles , Distribuição de Qui-Quadrado , China/epidemiologia , Estudos Transversais , Frequência do Gene , Predisposição Genética para Doença , Células Hep G2 , Hepatite B/epidemiologia , Vírus da Hepatite B/crescimento & desenvolvimento , Vírus da Hepatite B/metabolismo , Vírus da Hepatite B/patogenicidade , Humanos , Neoplasias Hepáticas/epidemiologia , Fenótipo , Fatores de Risco , Transativadores/metabolismo , Transfecção , Proteínas Virais Reguladoras e Acessórias , Replicação Viral
17.
Nat Genet ; 40(12): 1445-53, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19011630

RESUMO

Motile cilia induce fluid movement through their rhythmic beating activity. In mammals, the transcription factor Foxj1 has been implicated in motile cilia formation. Here we show that a zebrafish Foxj1 homolog, foxj1a, is a target of Hedgehog signaling in the floor plate. Loss of Foxj1a compromises the assembly of motile cilia that decorate floor plate cells. Besides the floor plate, foxj1a is expressed in Kupffer's vesicle and pronephric ducts, where it also promotes ciliary differentiation. We show that Foxj1a activates a constellation of genes essential for motile cilia formation and function, and that its activity is sufficient for ectopic development of cilia that resemble motile cilia. We also document that a paralogous gene, foxj1b, is expressed in the otic vesicle and seems to regulate motile cilia formation in this tissue. Our findings identify a dedicated master regulatory role for Foxj1 in the transcriptional program that controls the production of motile cilia.


Assuntos
Cílios/metabolismo , Fatores de Transcrição Forkhead/genética , Peixe-Zebra/embriologia , Peixe-Zebra/genética , Animais , Fatores de Transcrição Forkhead/metabolismo , Proteínas Hedgehog/metabolismo , Dados de Sequência Molecular , Transdução de Sinais , Proteínas de Peixe-Zebra
18.
J Cell Sci ; 117(Pt 17): 3839-53, 2004 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-15265985

RESUMO

Recent studies have suggested that the function of the large GTPase dynamin in endocytosis in mammalian cells may comprise a modulation of actin cytoskeleton. The role of dynamin in actin cytoskeleton organization in the yeast Saccharomyces cerevisiae has remained undefined. In this report, we found that one of the yeast dynamin-related proteins, Vps1p, is required for normal actin cytoskeleton organization. At both permissive and non-permissive temperatures, the vps1 mutants exhibited various degrees of phenotypes commonly associated with actin cytoskeleton defects: depolarized and aggregated actin structures, hypersensitivity to the actin cytoskeleton toxin latrunculin-A, randomized bud site selection and chitin deposition, and impaired efficiency in the internalization of membrane receptors. Over-expression of the GTPase mutants of vps1 also led to actin abnormalities. Consistent with these actin-related defects, Vps1p was found to interact physically, and partially co-localize, with the actin-regulatory protein Sla1p. The normal cellular localization of Sla1p required Vps1p and could be altered by over-expression of a region of Vps1p that was involved in the interaction with Sla1p. The same region also promoted mis-sorting of the vacuolar protein carboxypeptidase Y upon over-expression. These findings suggest that the functions of the dynamin-related protein Vps1p in actin cytoskeleton dynamics and vacuolar protein sorting are probably related to each other.


Assuntos
Actinas/metabolismo , Proteínas de Transporte/fisiologia , Citoesqueleto/fisiologia , Dinaminas/metabolismo , Proteínas de Ligação ao GTP/fisiologia , Proteínas de Saccharomyces cerevisiae/fisiologia , Sequência de Aminoácidos , Transporte Biológico , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Proteínas de Transporte/química , Catepsina A/química , Morte Celular , Membrana Celular/metabolismo , Proteínas do Citoesqueleto , Citoesqueleto/metabolismo , Endocitose , GTP Fosfo-Hidrolases/metabolismo , Proteínas de Ligação ao GTP/metabolismo , Genótipo , Imunoprecipitação , Microscopia de Fluorescência , Dados de Sequência Molecular , Mutação , Oligonucleotídeos/química , Plasmídeos/metabolismo , Ligação Proteica , Estrutura Terciária de Proteína , Proteínas de Saccharomyces cerevisiae/química , Temperatura , Tiazóis/farmacologia , Tiazolidinas , Fatores de Tempo , Proteínas de Transporte Vesicular , Domínios de Homologia de src
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