330 research outputs found
A balance between NF-Y and p53 governs the pro- and anti-apoptotic transcriptional response
The transcription factor NF-Y is a trimer with histone-like subunits that binds and activates CCAAT-containing promoters. NF-Y controls the expression of several key regulators of the cell cycle. In this study, we examined the functional and molecular effects of NF-YB knockdown. Cell cycle progression is affected with a G2/M-specific depletion. This is due to the inability of activation of G2/M-specific genes, as evidenced by expression profiling, RT-PCR and ChIP data. Surprisingly, apoptosis is also observed, with Caspase 3/7/8 cleavage. A role of p53 and Bcl-2 family members is important. NF-YB inactivation is sufficient to functionally activate p53, in the absence of DNA damage. Failure to maintain a physiologic level of CCAAT-dependent transcription of anti-apoptotic genes contributes to impairment of Bax/Bcl-2 and Bax/Bcl-XL ratios. Our data highlight the importance of fine balancing the NF-Y-p53 duo for cell survival by (i) maintaining transcription of anti-apoptotic genes and (ii) preventing p53 activation that triggers the apoptotic cascade
Transcription factor Sp1 is essential for early embryonic development but dispensable for cell growth and differentiation.
Transcription factor Sp1 has been implicated in the expression of many genes. Moreover, it has been suggested that Sp1 is linked to the maintenance of methylation-free CpG islands, the cell cycle, and the formation of active chromatin structures. We have inactivated the mouse Sp1 gene. Sp1-/- embryos are retarded in development, show a broad range of abnormalities, and die around day 11 of gestation. In Sp1-/- embryos, the expression of many putative target genes, including cell cycle-regulated genes, is not affected, CpG islands remain methylation free, and active chromatin is formed at the globin loci. However, the expression of the methyl-CpG-binding protein MeCP2 is greatly reduced in Sp1-/- embryos. MeCP2 is thought to be required for the maintenance of differentiated cells. We suggest that Sp1 is an important regulator of this process
Investigating different representations for modeling and controlling multiple emotions in DNN-based speech synthesis
Sound categories : category formation and evidence-based taxonomies
Five evidence-based taxonomies of everyday sounds frequently reported in the soundscape literature have been generated. An online sorting and category-labelling method that elicits rather than prescribes descriptive words was used. A total of N=242 participants took part. The main categories of the soundscape taxonomy were people, nature, and manmade, with each dividing into further categories. Sounds within the nature and manmade categories, and two further individual sound sources, dogs and engines, were explored further by repeating the procedure using multiple exemplars. By generating multidimensional spaces containing both sounds and the spontaneously generated descriptive words the procedure allows for the interpretation of the psychological dimensions along which sounds are organized. This reveals how category formation is based upon different cues - sound source-event identification, subjective-states, and explicit assessment of the acoustic signal - in different contexts. At higher levels of the taxonomy the majority of words described sound source-events. In contrast, when categorizing dog sounds a greater proportion of the words described subjective-states, and valence and arousal scores of these words correlated with their coordinates along the first two dimensions of the data. This is consistent with valence and arousal judgements being the primary categorization strategy used for dog sounds. In contrast, when categorizing engine sounds a greater proportion of the words explicitly described the acoustic signal. The coordinates of sounds along the first two dimensions were found to correlate with fluctuation strength and sharpness, consistent with explicit assessment of acoustic signal features underlying category formation for engine sounds. By eliciting descriptive words the method makes explicit the subjective meaning of these judgements based upon valence and arousal and acoustic properties, and the results demonstrate distinct strategies being spontaneously used to categorize different types of sounds
Pharmacological Applications of Bile Acids and Their Derivatives in the Treatment of Metabolic Syndrome
Apart from well-known functions of bile acids in digestion and solubilization of lipophilic
nutrients and drugs in the small intestine, the emerging evidence from the past two
decades identified the role of bile acids as signaling, endocrine molecules that regulate
the glucose, lipid, and energy metabolism through complex and intertwined pathways
that are largely mediated by activation of nuclear receptor farnesoid X receptor (FXR)
and cell surface G protein-coupled receptor 1, TGR5 (also known as GPBAR1).
Interactions of bile acids with the gut microbiota that result in the altered composition
of circulating and intestinal bile acids pool, gut microbiota composition and modified
signaling pathways, are further extending the complexity of biological functions of these
steroid derivatives. Thus, bile acids signaling pathways have become attractive targets
for the treatment of various metabolic diseases and metabolic syndrome opening the
new potential avenue in their treatment. In addition, there is a significant effort to
unveil some specific properties of bile acids relevant to their intrinsic potency and
selectivity for particular receptors and to design novel modulators of these receptors with
improved pharmacokinetic and pharmacodynamic profiles. This resulted in synthesis
of few semi-synthetic bile acids derivatives such as 6a-ethyl-chenodeoxycholic acid
(obeticholic acid, OCA), norursodeoxycholic acid (norUDCA), and 12-monoketocholic
acid (12-MKC) that are proven to have positive effect in metabolic and hepato-biliary
disorders. This review presents an overview of the current knowledge related to bile
acids implications in glucose, lipid and energy metabolism, as well as a potential
application of bile acids in metabolic syndrome treatment with future perspectives
New insights into the role of motion and form vision in neurodevelopmental disorders
A selective deficit in processing the global (overall) motion, but not form, of spatially extensive objects in the visual scene is frequently associated with several neurodevelopmental disorders, including preterm birth. Existing theories that proposed to explain the origin of this visual impairment are, however, challenged by recent research. In this review, we explore alternative hypotheses for why deficits in the processing of global motion, relative to global form, might arise. We describe recent evidence that has utilised novel tasks of global motion and global form to elucidate the underlying nature of the visual deficit reported in different neurodevelopmental disorders. We also examine the role of IQ and how the sex of an individual can influence performance on these tasks, as these are factors that are associated with performance on global motion tasks, but have not been systematically controlled for in previous studies exploring visual processing in clinical populations. Finally, we suggest that a new theoretical framework is needed for visual processing in neurodevelopmental disorders and present recommendations for future research
Circulating microparticles: square the circle
Background: The present review summarizes current knowledge about microparticles (MPs) and provides a systematic overview of last 20 years of research on circulating MPs, with particular focus on their clinical relevance. Results: MPs are a heterogeneous population of cell-derived vesicles, with sizes ranging between 50 and 1000 nm. MPs are capable of transferring peptides, proteins, lipid components, microRNA, mRNA, and DNA from one cell to another without direct cell-to-cell contact. Growing evidence suggests that MPs present in peripheral blood and body fluids contribute to the development and progression of cancer, and are of pathophysiological relevance for autoimmune, inflammatory, infectious, cardiovascular, hematological, and other diseases. MPs have large diagnostic potential as biomarkers; however, due to current technological limitations in purification of MPs and an absence of standardized methods of MP detection, challenges remain in validating the potential of MPs as a non-invasive and early diagnostic platform. Conclusions: Improvements in the effective deciphering of MP molecular signatures will be critical not only for diagnostics, but also for the evaluation of treatment regimens and predicting disease outcomes
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