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Selective control of Pax7 expression by TNF-activated p38α/polycomb repressive complex 2 (PRC2) signaling during muscle satellite cell differentiation.
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Endothelial activation by angiotensin II through NFkappaB and p38 pathways: Involvement of NFkappaB-inducible kinase (NIK), free oxygen radicals, and selective inhibition by aspirin.
No full textp38 pathway targets SWI-SNF chromatin-remodeling complex to muscle-specific loci
No full textDuring skeletal myogenesis, genomic reprogramming toward terminal differentiation is achieved by recruiting chromatin-modifying enzymes to muscle-specific loci(1,2). The relative contribution of extracellular signaling cascades in targeting these enzymes to individual genes is unknown. Here we show that the differentiation-activated p38 pathway(3-5) targets the SWI-SNF chromatin-remodeling complex to myogenic loci. Upon differentiation, p38 kinases were recruited to the chromatin of muscle-regulatory elements. Blockade of p38alpha/beta repressed the transcription of muscle genes by preventing recruitment of the SWI-SNF complex at these elements without affecting chromatin binding of muscle-regulatory factors and acetyltransferases. The SWI-SNF subunit BAF60 could be phosphorylated by p38alpha-beta in vitro, and forced activation of p38alpha/beta in myoblasts by expression of a constitutively active MKK6 (refs. 5-7) promoted unscheduled SWI-SNF recruitment to the myogenin promoter. Conversely, inactivation of SWI-SNF enzymatic subunits abrogated MKK6-dependent induction of muscle gene expression. These results identify an unexpected function of differentiation-activated p38 in converting external cues into chromatin modifications at discrete loci, by selectively targeting SWI-SNF to muscle-regulatory elements
Oral Presentation: A novel AMPK-dependent FoxO3A-SIRT3 intramitochondrial complex sensing glucose levels.
No full textReduction of nutrient intake without malnutrition positively influences lifespan and healthspan from yeast to mice and exerts some beneficial effects also in humans. The AMPK-FoxO axis is one of the evolutionarily conserved nutrient-sensing pathways, and the FOXO3A locus is associated with human longevity. Interestingly, FoxO3A has been reported to be also a mitochondrial protein in mammalian cells and tissues. Here we report that glucose restriction triggers FoxO3A accumulation into mitochondria of fibroblasts and skeletal myotubes in an AMPK-dependent manner. A low-glucose regimen induces the formation of a protein complex containing FoxO3A, SIRT3, and mitochondrial RNA polymerase (mtRNAPol) at mitochondrial DNA-regulatory regions causing activation of the mitochondrial genome and a subsequent increase in mitochondrial respiration. Consistently, mitochondrial transcription increases in skeletal muscle of fasted mice, with a mitochondrial DNA-bound FoxO3A/SIRT3/mtRNAPol complex detectable also in vivo. Our results unveil a mitochondrial arm of the AMPK-FoxO3A axis acting as a recovery mechanism to sustain energy metabolism upon nutrient restriction
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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