4,443 research outputs found
Tyrosine Phosphorylation of p68 RNA Helicase Promotes Metastasis in Colon Cancer Progression
The initiation of cancer metastasis usually requires Epithelial-Mesenchymal Transition (EMT), by which tumor cells lose cell-cell interactions and gain the ability of migration and invasion. Previous study demonstrated that p68 RNA helicase, a prototypical member of the DEAD-box RNA helicases, functions as a mediator to promote platelet-derived growth factor (PDGF)-induced EMT through facilitating nuclear translocation of β-catenin in colon cancer cells. In this context, p68 RNA helicase was found to be phosphorylated at the tyrosine 593 residue (referred as phosphor-p68) by c-Abl kinase, and this phosphorylation is required for the activation of β-catenin signaling and the consequent EMT. The phosphor-p68 RNA helicase-mediated EMT was characterized by the repression of an epithelial marker, E-cadherin, and the upregulation of a mesenchymal marker, Vimentin. E-cadherin, a major cell-cell adhesion molecule that is involved in the formation of adherens junctions, has been shown to sequester β-catenin at the cell membrane and thus inhibit its transcriptional activity. The functional loss of E-cadherin is the fundamental event of EMT. Despite the role of phosphor-p68 RNA helicase in regulating nuclear translocation of β-catenin, whether phosphor-p68 is involved in the regulation of E-cadherin remains unknown. Here, our data indicated that phosphor-p68 RNA helicase initiated EMT by transcriptional upregulation of Snail1, a master transcriptional repressor of E-cadherin. The data suggest that phosphor-p68 RNA helicase displaced HDAC1 from the chromatin remodeling MBD3:Mi-2/NuRD complex at the Snail1 promoter, thereby activating the transcription of Snail1. In the xenograft tumor model, abolishing the phosphorylation of p68 RNA helicase by the expression of Y593F mutant resulted in a significant reduction of metastatic potential in human colon cancer cells. Analyses in the colon cancer tissues also revealed that the tyrosine 593 phosphorylation level of p68 RNA helicase is substantially enhanced in the tumor tissues comparing to that in the corresponding normal counterparts, suggesting a correlation of phosphor-p68 and tumor progression. In conclusion, we showed that tyrosine phosphorylation of p68 RNA helicase positively correlated to the malignant status of colon cancer progression. The molecular basis behind this correlation could be partly through the transcriptional regulation of Snail1
Revisiting the problem of audio-based hit song prediction using convolutional neural networks
Being able to predict whether a song can be a hit has impor- tant
applications in the music industry. Although it is true that the popularity of
a song can be greatly affected by exter- nal factors such as social and
commercial influences, to which degree audio features computed from musical
signals (whom we regard as internal factors) can predict song popularity is an
interesting research question on its own. Motivated by the recent success of
deep learning techniques, we attempt to ex- tend previous work on hit song
prediction by jointly learning the audio features and prediction models using
deep learning. Specifically, we experiment with a convolutional neural net-
work model that takes the primitive mel-spectrogram as the input for feature
learning, a more advanced JYnet model that uses an external song dataset for
supervised pre-training and auto-tagging, and the combination of these two
models. We also consider the inception model to characterize audio infor-
mation in different scales. Our experiments suggest that deep structures are
indeed more accurate than shallow structures in predicting the popularity of
either Chinese or Western Pop songs in Taiwan. We also use the tags predicted
by JYnet to gain insights into the result of different models.Comment: To appear in the proceedings of 2017 IEEE International Conference on
Acoustics, Speech and Signal Processing (ICASSP
A Systems Approach to Institutional Diffusion in Taiwanâs Food Traceability System
A food traceability system is an institution that aims to reduce information asymmetry among producers, retailers, and consumers through public disclosure of information about the origin, production, and sales of agriproducts. System effectiveness depends on the changes that result from diffusion. In this study, we use Taiwanâs traceable agricultural products system to integrate mental models of multiple stakeholders to simulate interactions among institutional quality, adopter profitability, profit distribution, and institutional diffusion from a system dynamics perspective. It thus provides a framework for institutional diffusion and change and elucidates the process of institutional diffusion for the causal relations among many critical factors
Understanding chronic inflammatory diseases in the human lung: the cystic fibrosis and idiopathic pulmonary fibrosis paradigms
The chronic infection of the cystic fibrosis (CF) lung with Pseudomonas aeruginosa strongly correlates with critical outcomes. Pseudomonas alkyl-quinolone signal (PQS) is a diffusible cell-density dependent signal controlling the production of virulence determinants. The PQS amount in the CF lung was proportionate to P. aeruginosa colonisation and PQS molecules have been demonstrated to inhibit pro-inflammatory signalling. However, how PQS influence the recognition of P. aeruginosa by the human lung is unknown. The contribution of PQS to the interaction of P. aeruginosa with human bronchial epithelial cells (HBECs) was characterised using a PQS-deficient mutant ÎpqsA in comparison with its isogenic wild type (WT). Although ÎpqsA appeared attenuated, the pathogenesis of WT and ÎpqsA upon infection of HBEC did not differ in bacterial growth, actin and junctional protein degradation, and pro-inflammatory activation. Despite PQS being highly secreted by a CF isolate LESB58, preliminary data showed that LESB58 was less cytotoxic than the laboratory WT. Our results suggest that PQS does not alter P. aeruginosa pathogenicity on HBECs.
Idiopathic pulmonary fibrosis (IPF) is characterised with heterogeneous pathological patterns caused by scarring leading to irreversible destruction of lung architecture. Emerging evidence suggests that dysregulated immunological events could cause the failure of tissue-healing. Systemic immune responses of patients with IPF and age- and sex-matched healthy donors were determined by quantifying cytokines produced by peripheral blood mononuclear cells (PBMCs) upon an array of stimuli. The results showed that PBMCs in patients with IPF were less likely to produce IL-17A, IL-10 and IL-13 than healthy controls (OR 0.14-0.3, 95% CI 0.003-0.03). Patients with lower levels of cytokines had a four to six-fold increased risk of death (HR 4.31-6.13, 95% CI 0.0052-0.0176).
This study contributes to a better understanding of the role of PQS in P. aeruginosa pathogenesis and identified cytokine production as a novel biomarker in IPF
Molecular weaponry:diverse effectors delivered by the Type VI secretion system
The Type VI secretion system is a widespread bacterial nanomachine, used to deliver toxins directly into eukaryotic or prokaryotic target cells. These secreted toxins, or effectors, act on diverse cellular targets, and their action provides the attacking bacterial cell with a significant fitness advantage, either against rival bacteria or eukaryotic host organisms. In this review, we discuss the delivery of diverse effectors by the Type VI secretion system, the modes of action of the soâcalled âantiâbacterialâ and âantiâeukaryoticâ effectors, the mechanism of selfâresistance against antiâbacterial effectors and the evolutionary implications of horizontal transfer of Type VI secretion systemâassociated toxins. Whilst it is likely that many more effectors remain to be identified, it is already clear that toxins delivered by this secretion system represent efficient weapons against both bacteria and eukaryotes
Understanding chronic inflammatory diseases in the human lung: the cystic fibrosis and idiopathic pulmonary fibrosis paradigms
The chronic infection of the cystic fibrosis (CF) lung with Pseudomonas aeruginosa strongly correlates with critical outcomes. Pseudomonas alkyl-quinolone signal (PQS) is a diffusible cell-density dependent signal controlling the production of virulence determinants. The PQS amount in the CF lung was proportionate to P. aeruginosa colonisation and PQS molecules have been demonstrated to inhibit pro-inflammatory signalling. However, how PQS influence the recognition of P. aeruginosa by the human lung is unknown. The contribution of PQS to the interaction of P. aeruginosa with human bronchial epithelial cells (HBECs) was characterised using a PQS-deficient mutant ÎpqsA in comparison with its isogenic wild type (WT). Although ÎpqsA appeared attenuated, the pathogenesis of WT and ÎpqsA upon infection of HBEC did not differ in bacterial growth, actin and junctional protein degradation, and pro-inflammatory activation. Despite PQS being highly secreted by a CF isolate LESB58, preliminary data showed that LESB58 was less cytotoxic than the laboratory WT. Our results suggest that PQS does not alter P. aeruginosa pathogenicity on HBECs.
Idiopathic pulmonary fibrosis (IPF) is characterised with heterogeneous pathological patterns caused by scarring leading to irreversible destruction of lung architecture. Emerging evidence suggests that dysregulated immunological events could cause the failure of tissue-healing. Systemic immune responses of patients with IPF and age- and sex-matched healthy donors were determined by quantifying cytokines produced by peripheral blood mononuclear cells (PBMCs) upon an array of stimuli. The results showed that PBMCs in patients with IPF were less likely to produce IL-17A, IL-10 and IL-13 than healthy controls (OR 0.14-0.3, 95% CI 0.003-0.03). Patients with lower levels of cytokines had a four to six-fold increased risk of death (HR 4.31-6.13, 95% CI 0.0052-0.0176).
This study contributes to a better understanding of the role of PQS in P. aeruginosa pathogenesis and identified cytokine production as a novel biomarker in IPF
Management of Tuberculosis in Taiwan:A Look into the Shared Responsibilities of the Government, General Public and Medical Students
Tuberculosis (TB) is a deadly infectious disease worldwide due to its high incidenceand mortality rate. Its impact on Taiwan is no exception. This paper aims to examineeffectiveness of national policies on TB control, assess public awareness, and evaluatewhether involvement of medical students would have a positive effect towards TBcontrol in Taiwan.Literatures were first reviewed to assess effectiveness of Directly Observed Treatment,Short-course (DOTS). Although there is limited improvement in treatment success inTaiwan, there is an overall positive effect.Questionnaires designed to assess public knowledge and behaviors revealedinadequate public knowledge about DOTS, which could have led to the lack ofdistinct success in the national policy. Healthcare workshops were conducted by medical students, with survey resultsshowing a significant improvement in participantsâ knowledge. Thus, medicalstudents are recommended to engage in healthcare activities to effectively aid TBcontrol.
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Rejuvenation of brain, liver and muscle by simultaneous pharmacological modulation of two signaling determinants, that change in opposite directions with age.
We hypothesize that altered intensities of a few morphogenic pathways account for most/all the phenotypes of aging. Investigating this has revealed a novel approach to rejuvenate multiple mammalian tissues by defined pharmacology. Specifically, we pursued the simultaneous youthful in vivo calibration of two determinants: TGF-beta which activates ALK5/pSmad 2,3 and goes up with age, and oxytocin (OT) which activates MAPK and diminishes with age. The dose of Alk5 inhibitor (Alk5i) was reduced by 10-fold and the duration of treatment was shortened (to minimize overt skewing of cell-signaling pathways), yet the positive outcomes were broadened, as compared with our previous studies. Alk5i plus OT quickly and robustly enhanced neurogenesis, reduced neuro-inflammation, improved cognitive performance, and rejuvenated livers and muscle in old mice. Interestingly, the combination also diminished the numbers of cells that express the CDK inhibitor and marker of senescence p16 in vivo. Summarily, simultaneously re-normalizing two pathways that change with age in opposite ways (up vs. down) synergistically reverses multiple symptoms of aging
Illiquidity Premium and Monetary Conditions in Emerging Markets: An Empirical Examination of Taiwan Stock Markets
This study empirically examines the illiquidity premium of Taiwan stock markets and its relationship with monetary policies. We find that commonly used illiquidity measures are generally sensitive and capable of capturing market illiquidity, particularly during the most volatile periods. Evidence shows that unconditional illiquidity is significantly priced across three illiquidity measures during the sample period. Aggregate market illiquidity innovations are noticeably affected by monetary policies. The results of Granger causality tests reveal that expansive monetary policy improves market illiquidity, whereas restrictive policy adversely affects market liquidity.
Keywords: Illiquidity; illiquidity premium; monetary policy; asset pricing; Granger's causality tests
JEL Classifications: G11, G12, G15
DOI: https://doi.org/10.32479/ijefi.895
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