Based on digital media technology, this paper defines Chinese art theory and, at the same time, combines digital media technology and the characteristics of Chinese art aesthetic discourse to ...construct an art aesthetic discourse system that covers the stage of sensory experience and the stage of “emotional experience”. In order to promote the digitalization of the art aesthetic discourse system, the MCFF algorithm is used to extract the features of art aesthetic discourse, match the features, and then merge the features of art aesthetic discourse based on the weighted summing algorithm so as to achieve the digitization of art aesthetic discourse features. The art aesthetic discourse system in digital media is analyzed based on the research data. The results show that compared with the traditional algorithm, the algorithm of this paper is better than the traditional algorithm in three aspects: pre-emphasis (growth rate of 62.70%), frame-plus-window (growth rate of 68.71%), and data conversion (growth rate of 72.14%). In addition, the aesthetic experiences of landscape painting and figure painting were 96.49±8.4 and 108.00±9.35 points, respectively, and F(1, 20)=20.746, p<0.05, indicating that there is a significant difference in the sensory experience in the aesthetic discourse of art. This study can not only promote dialogue between art creators and scholars but also provide theoretical guidance and practical feedback for the future development of the art field.
Protein O-linked β-N-acetylglucosamine (O-GlcNAc) modification (O-GlcNAcylation) is a unique monosaccharide modification discovered in the early 1980s. With the technological advances in the past ...several decades, great progress has been made to reveal the biochemistry of O-GlcNAcylation, the substrates of O-GlcNAcylation, and the functional importance of protein O-GlcNAcylation. As a nutrient sensor, protein O-GlcNAcylation plays important roles in almost all biochemical processes examined. Although the functional importance of O-GlcNAcylation of proteins has been extensively reviewed previously, the chemical and biochemical aspects have not been fully addressed. In this review, by critically evaluating key publications in the past 35 years, we aim to provide a comprehensive understanding of this important post-translational modification (PTM) from analytical and biochemical perspectives. Specifically, we will cover (1) multiple analytical advances in the characterization of O-GlcNAc cycling components (i.e., the substrate donor UDP-GlcNAc, the two key enzymes O-GlcNAc transferase and O-GlcNAcase, and O-GlcNAc substrate proteins), (2) the biochemical characterization of the enzymes with a variety of chemical tools, and (3) exploration of O-GlcNAc cycling and its modulating chemicals as potential biomarkers and therapeutic drugs for diseases. Last but not least, we will discuss the challenges and possible solutions for basic and translational research of protein O-GlcNAcylation in the future.
O-linked β-N-acetylglucosamine (O-GlcNAc) is a post-translational modification (i.e., O-GlcNAcylation) on the serine/threonine residues of proteins. As a unique intracellular monosaccharide ...modification, protein O-GlcNAcylation plays important roles in almost all biochemical processes examined. Aberrant O-GlcNAcylation underlies the etiologies of a number of chronic diseases. With the tremendous improvement of techniques, thousands of proteins along with their O-GlcNAc sites have been reported. However, until now, there are few databases dedicated to accommodate the rapid accumulation of such information. Thus, O-GlcNAcAtlas is created to integrate all experimentally identified O-GlcNAc sites and proteins. O-GlcNAcAtlas consists of two datasets (Dataset-I and Dataset-II, for unambiguously identified sites and ambiguously identified sites, respectively), representing a total number of 4571 O-GlcNAc modified proteins from all species studied from 1984 to 31 Dec 2019. For each protein, comprehensive information (including species, sample type, gene symbol, modified peptides and/or modification sites, site mapping methods and literature references) is provided. To solve the heterogeneity among the data collected from different sources, the sequence identity of these reported O-GlcNAc peptides are mapped to the UniProtKB protein entries. To our knowledge, O-GlcNAcAtlas is a highly comprehensive and rigorously curated database encapsulating all O-GlcNAc sites and proteins identified in the past 35 years. We expect that O-GlcNAcAtlas will be a useful resource to facilitate O-GlcNAc studies and computational analyses of protein O-GlcNAcylation. The public version of the web interface to the O-GlcNAcAtlas can be found at http://oglcnac.org/.
Elevated mitochondrial O -GlcNAcylation caused by hyperglycemia, as occurs in diabetes, significantly contributes to mitochondrial dysfunction and to diabetic cardiomyopathy. However, little is known ...about the enzymology of mitochondrial O -GlcNAcylation. Herein, we investigated the enzymes responsible for cycling O -GlcNAc on mitochondrial proteins and studied the mitochondrial transport of UDP-GlcNAc. Analyses of purified rat heart mitochondria from normal and streptozocin-treated diabetic rats show increased mitochondrial O -GlcNAc transferase (OGT) and a concomitant decrease in the mito-specific O-GlcNAcase (OGA). Strikingly, OGT is mislocalized in cardiac mitochondria from diabetic rats. Interaction of OGT and complex IV observed in normal rat heart mitochondria is visibly reduced in diabetic samples, where OGT is mislocalized to the matrix. Live cell OGA activity assays establish the presence of O-GlcNAcase within the mitochondria. Furthermore, we establish that the inner mitochondrial membrane transporter, pyrimidine nucleotide carrier, transports UDP-GlcNAc from the cytosol to the inside of the mitochondria. Knockdown of this transporter substantially lowers mitochondrial O -GlcNAcylation. Inhibition of OGT or OGA activity within neonatal rat cardiomyocytes significantly affects energy production, mitochondrial membrane potential, and mitochondrial oxygen consumption. These data suggest that cardiac mitochondria not only have robust O -GlcNAc cycling, but also that dysregulation of O -GlcNAcylation likely plays a key role in mitochondrial dysfunction associated with diabetes.
Significance Mitochondrial dysfunction contributes significantly to glucose toxicity in diabetes. Increased O -GlcNAcylation is emerging as a major molecular cause of glucose toxicity via many mechanisms. The studies herein provide a direct molecular link between hyperglycemia and mitochondrial dysfunction. We show that mitochondrial O -GlcNAc transferase (OGT) and O-GlcNAcase (OGA) expression levels and localizations are strikingly different between normal and diabetic rat hearts. We also discover how UDP-GlcNAc enters the mitochondrial space. Finally our data demonstrate that OGT and OGA play significant roles in ATP production, mitochondrial membrane potential, and oxygen consumption. These studies are of general interest not only with respect to nutrient regulation of mitochondrial function, but also are important to elucidate mechanisms of diabetic complications.
O-linked β-D-N-acetylglucosamine (O-GlcNAc) modification (O-GlcNAcylation) onto serine and threonine residues of proteins is an important post-translational modification (PTM), which is involved in ...many crucial biological processes including transcription, translation, proteasomal degradation, and signal transduction. Aberrant protein O-GlcNAcylation is directly linked to the pathological progression of chronic diseases including diabetes, cancer, and neurodegenerative disorders. Identification, site mapping, and quantification of O-GlcNAc proteins are a prerequisite to decipher their functions. In this review, we mainly focus on technological developments regarding O-GlcNAc protein profiling. Specifically, on one hand, we show how these techniques are being used for the comprehensive characterization of certain targeted proteins in which biologists are most interested. On the other hand, we present several newly developed approaches for O-GlcNAcomic profiling as well as how they provide us with a systems perspective to crosstalk amongst different PTMs and complicated biological events. Promising technical trends are also highlighted to evoke more efforts by diverse laboratories, which would further expand our understanding of the physiological and pathological roles of protein O-GlcNAcylation in chronic diseases.
Over the last decade, the development and prevalence of obesity have posed a serious public health risk, which has prompted studies on the regulation of adiposity. With the ease of genetic ...manipulation, the diversity of the methods for characterizing body fat levels, and the observability of feeding behavior,
(
) is considered an excellent model for exploring energy homeostasis and the regulation of the cellular fat storage. In addition, the homology with mammals in the genes related to the lipid metabolism allows many aspects of lipid modulation by the regulators of the central nervous system to be conserved in this ideal model organism. In recent years, as the complex network of genes that maintain an energy balance has been gradually expanded and refined, the regulatory mechanisms of lipid storage have become clearer. Furthermore, the development of methods and devices to assess the lipid levels has become a powerful tool for studies in lipid droplet biology and the regulation of the nematode lipid metabolism. Herein, based on the rapid progress of
lipid metabolism-related studies, this review outlined the lipid metabolic processes, the major signaling pathways of fat storage regulation, and the primary experimental methods to assess the lipid content in nematodes. Therefore, this model system holds great promise for facilitating the understanding, management, and therapies of human obesity and other metabolism-related diseases.
Interactions between proteins are essential to any cellular process and constitute the basis for molecular networks that determine the functional state of a cell. With the technical advances in ...recent years, an astonishingly high number of protein–protein interactions has been revealed. However, the interactome of O-linked N-acetylglucosamine transferase (OGT), the sole enzyme adding the O-linked β-N-acetylglucosamine (O-GlcNAc) onto its target proteins, has been largely undefined. To that end, we collated OGT interaction proteins experimentally identified in the past several decades. Rigorous curation of datasets from public repositories and O-GlcNAc-focused publications led to the identification of up to 929 high-stringency OGT interactors from multiple species studied (including Homo sapiens, Mus musculus, Rattus norvegicus, Drosophila melanogaster, Arabidopsis thaliana, and others). Among them, 784 human proteins were found to be interactors of human OGT. Moreover, these proteins spanned a very diverse range of functional classes (e.g., DNA repair, RNA metabolism, translational regulation, and cell cycle), with significant enrichment in regulating transcription and (co)translation. Our dataset demonstrates that OGT is likely a hub protein in cells. A webserver OGT-Protein Interaction Network (OGT-PIN) has also been created, which is freely accessible.
In current study, a novel monolithic capillary column with embedded attapulgite nanoparticles has been developed and exploited as a stationary phase in hydrophilic in-tube solid phase microextraction ...(SPME) of cyromazine and melamine. The fibrillar attapulgite nanoparticles were embedded in the poly(1-vinyl-3-(butyl-4-sulfonate) imidazolium-co-acrylamide-co-N,N′-methylenebis(acrylamide)) (poly(VBSIm-AM-MBA)) monolith via in situ polymerization. The attapulgite/polymerization ratio of the monolith was finely optimized. Primary factors of in-tube SPME including sample solvent, elution solvent, sample loading volume, elution volume, sample loading flow rate, and elution flow rate were thoroughly evaluated. Under optimal conditions, the limits of detection (LODs) were found to be 21.1 and 0.3 ng mL–1 for cyromazine and melamine in the milk formula sample, respectively. Also, the recoveries of cyromazine and melamine spiked in the sample ranged from 94.5% to 109.9% with RSDs less than 7.6%.
Low-grade appendiceal mucinous neoplasms (LAMNs) are rare and heterogeneous diseases that, despite their increased incidence, are well differentiated, tend to be painless, and histologically lack ...distinctive invasive features without infiltrative growth, destructive infiltration, or associated pro-fibroproliferative responses. However, the biological behaviour of these tumours is difficult to determine preoperatively or intraoperatively, and the possibility of rupture puts patients at risk for peritoneal pseudomucinous neoplasms (PMPs).Patients with low-grade appendiceal mucinous tumours and peritoneal pseudomucinous tumours experience slow disease progression and are incurable and have a high risk of recurrence, morbidity, and ultimately death, despite the reported 5- and 10-year survival rates of 50–86% and 45–68%, respectively. In this article, we report the case of a 80-year-old male with a giant low-grade appendiceal mucinous tumour associated with a peritoneal pseudomucinous tumour, and discuss the diagnostic and management strategies for giant low-grade appendiceal mucinous tumours in the context of a literature review.
Loss of primary cilia is frequently observed in tumor cells, suggesting that the absence of this organelle may promote tumorigenesis through aberrant signal transduction, the inability to exit the ...cell cycle, and promotion of tumor cell invasion. Primary cilia loss also occurs in esophageal squamous cell carcinoma (ESCC) cells, but the molecular mechanisms that explain how ESCC cells lose primary cilia remain poorly understood.
Inhibiting the expression of Prdx1 in the ESCC cells to detect the up-regulated genes related to cilium regeneration and down-regulated genes related to cilium disassembly by Gene chip. And, mice and cell experiments were carried to confirm the role of the HEF1-Aurora A-HDAC6 signaling axis in ESCC.
In this study, we found that silencing Peroxiredoxin 1 (Prdx1) restores primary cilia formation, and over-expressing Prdx1 induces primary cilia loss in ESCC cells. We also showed that the expression of Prdx1 regulates the action of the HEF1-Aurora A-HDAC6 signaling axis to promote the disassembly of primary cilia, and suppression of Prdx1 results in decreased tumor formation and tumor mass volume in vivo.
These results suggest that Prdx1 is a novel regulator of primary cilia formation in ESCC cells.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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