38 research outputs found
Dynamic regulation of canonical TGF beta signalling by endothelial transcription factor ERG protects from liver fibrogenesis
The role of the endothelium in protecting from chronic liver disease and TGFÎČ-mediated
fibrosis remains unclear. Here we describe how the endothelial transcription factor
ETS-related gene (ERG) promotes liver homoeostasis by controlling canonical TGFÎČ-SMAD
signalling, driving the SMAD1 pathway while repressing SMAD3 activity. Molecular analysis
shows that ERG binds to SMAD3, restricting its access to DNA. Ablation of ERG expression
results in endothelial-to-mesenchymal transition (EndMT) and spontaneous liver
fibrogenesis in EC-specific constitutive hemi-deficient (ErgcEC-Het) and inducible homozygous
deficient mice (ErgiEC-KO), in a SMAD3-dependent manner. Acute administration of the
TNF-α inhibitor etanercept inhibits carbon tetrachloride (CCL4)-induced fibrogenesis in an
ERG-dependent manner in mice. Decreased ERG expression also correlates with EndMT in
tissues from patients with end-stage liver fibrosis. These studies identify a pathogenic
mechanism where loss of ERG causes endothelial-dependent liver fibrogenesis via regulation
of SMAD2/3. Moreover, ERG represents a promising candidate biomarker for assessing
EndMT in liver disease
A RG-II type polysaccharide purified from Aconitum coreanum and their anti-inflammatory activity
Korean mondshood root polysaccharides (KMPS) isolated from the root of Aconitum coreanum (LĂ©vl.) Rapaics have shown anti-inflammatory activity, which is strongly influenced by their chemical structures and chain conformations. However, the mechanisms of the anti-inflammatory effect by these polysaccharides have yet to be elucidated. A RG-II polysaccharide (KMPS-2E, Mw 84.8 kDa) was isolated from KMPS and its chemical structure was characterized by FT-IR and NMR spectroscopy, gas chromatographyâmass spectrometry and high-performance liquid chromatography. The backbone of KMPS-2E consisted of units of [â6) -ÎČ-D-Galp (1â3)-ÎČ-L-Rhap-(1â4)-ÎČ-D-GalpA-(1â3)-ÎČ-D-Galp-(1â] with the side chain â5)-ÎČ-D-Arap (1â3, 5)-ÎČ-D-Arap (1â attached to the backbone through O-4 of (1â3,4)-L-Rhap. T-ÎČ-D-Galp is attached to the backbone through O-6 of (1â3,6)-ÎČ-D-Galp residues and T-ÎČ-D-Ara is connected to the end group of each chain. The anti-inflammatory effects of KMPS-2E and the underlying mechanisms using lipopolysaccharide (LPS) - stimulated RAW 264.7 macrophages and carrageenan-induced hind paw edema were investigated. KMPS-2E (50, 100 and 200 ”g/mL) inhibits iNOS, TLR4, phospho-NF-ÎșBâp65 expression, phosphor-IKK, phosphor-IÎșB-α expression as well as the degradation of IÎșB-α and the gene expression of inflammatory cytokines (TNF-α, IL-1ÎČ, iNOS and IL-6) mediated by the NF-ÎșB signal pathways in macrophages. KMPS-2E also inhibited LPS-induced activation of NF-ÎșB as assayed by electrophorectic mobility shift assay (EMSA) in a dose-dependent manner and it reduced NF-ÎșB DNA binding affinity by 62.1% at 200”g/mL. In rats, KMPS-2E (200 mg/kg) can significantly inhibit carrageenan-induced paw edema as ibuprofen (200 mg/kg) within 3 h after a single oral dose. The results indicate that KMPS-2E is a promising herb-derived drug against acute inflammation
First description of a fossil chamaeleonid from Greece and its relevance for the European biogeographic history of the group
The fossil record of Chamaeleonidae is very scarce and any new specimen is therefore considered important for our understanding of the evolutionary and biogeographic history of the group. New specimens from the early Miocene of Aliveri (Evia Island), Greece constitute the only fossils of these lizards from southeastern Europe. Skull roofing material is tentatively attributed to the Czech species Chamaeleo cf. andrusovi, revealing a range extension for this taxon, whereas tooth-bearing elements are described as indeterminate chamaeleonids. The Aliveri fossils rank well among the oldest known reptiles from Greece, provide evidence for the dispersal routes of chameleons out of Africa towards the European continent and, additionally, imply strong affinities with coeval chamaeleonids from Central Europe
Social preferences and network structure in a population of reef manta rays
Understanding how individual behavior shapes the structure and ecology ofpopulations is key to species conservation and management. Like manyelasmobranchs, manta rays are highly mobile and wide ranging species threatened byanthropogenic impacts. In shallow-water environments these pelagic rays often formgroups, and perform several apparently socially-mediated behaviors. Group structuresmay result from active choices of individual rays to interact, or passive processes.Social behavior is known to affect spatial ecology in other elasmobranchs, but this isthe first study providing quantitative evidence for structured social relationships inmanta rays. To construct social networks, we collected data from more than 500groups of reef manta rays over five years, in the Raja Ampat Regency of West Papua.We used generalized affiliation indices to isolate social preferences from non-socialassociations, the first study on elasmobranchs to use this method. Longer lastingsocial preferences were detected mostly between female rays. We detectedassortment of social relations by phenotype and variation in social strategies, with theoverall social network divided into two main communities. Overall network structurewas characteristic of a dynamic fission-fusion society, with differentiated relationshipslinked to strong fidelity to cleaning station sites. Our results suggest that fine-scaleconservation measures will be useful in protecting social groups of M. alfredi in theirnatural habitats, and that a more complete understanding of the social nature of mantarays will help predict population response
International lower limb collaborative (INTELLECT) study: a multicentre, international retrospective audit of lower extremity open fractures
Trauma remains a major cause of mortality and disability across the world1, with a higher burden in developing nations2. Open lower extremity injuries are devastating events from a physical3, mental health4, and socioeconomic5 standpoint. The potential sequelae, including risk of chronic infection and amputation, can lead to delayed recovery and major disability6. This international study aimed to describe global disparities, timely intervention, guideline-directed care, and economic aspects of open lower limb injuries
A Connection Between Symmetry Breaking for Sobolev Minimizers and Stationary NavierâStokes Flows Past a Circular Obstacle
Fluid flows around a symmetric obstacle generate vortices which may lead to symmetry breaking of the streamlines. We study this phenomenon for planar viscous flows governed by the stationary NavierâStokes equations with constant inhomogeneous Dirichlet boundary data in a rectangular channel containing a circular obstacle. In such (symmetric) framework, symmetry breaking is strictly related to the appearance of multiple solutions. Symmetry breaking properties of some Sobolev minimizers are studied and explicit bounds on the boundary velocity (in terms of the length and height of the channel) ensuring uniqueness are obtained after estimating some Sobolev embedding constants and constructing a suitable solenoidal extension of the boundary data. We show that, regardless of the solenoidal extension employed, such bounds converge to zero at an optimal rate as the length of the channel tends to infinity