Metabolic systems analysis of LPS induced endothelial dysfunction applied to sepsis patient stratification.

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked FilesEndothelial dysfunction contributes to sepsis outcome. Metabolic phenotypes associated with endothelial dysfunction are not well characterised in part due to difficulties in assessing endothelial metabolism in situ. Here, we describe the construction of iEC2812, a genome scale metabolic reconstruction of endothelial cells and its application to describe metabolic changes that occur following endothelial dysfunction. Metabolic gene expression analysis of three endothelial subtypes using iEC2812 suggested their similar metabolism in culture. To mimic endothelial dysfunction, an in vitro sepsis endothelial cell culture model was established and the metabotypes associated with increased endothelial permeability and glycocalyx loss after inflammatory stimuli were quantitatively defined through metabolomics. These data and transcriptomic data were then used to parametrize iEC2812 and investigate the metabotypes of endothelial dysfunction. Glycan production and increased fatty acid metabolism accompany increased glycocalyx shedding and endothelial permeability after inflammatory stimulation. iEC2812 was then used to analyse sepsis patient plasma metabolome profiles and predict changes to endothelial derived biomarkers. These analyses revealed increased changes in glycan metabolism in sepsis non-survivors corresponding to metabolism of endothelial dysfunction in culture. The results show concordance between endothelial health and sepsis survival in particular between endothelial cell metabolism and the plasma metabolome in patients with sepsis.RANNIS Landspitali Reykjavik Rigshospitalet Copenhage

Lögun og aukaæðar í vængjum þegar virkni Egfr genaafurðarinnar eru aukin

Ritgerðin er lokuð til janúar 2012Threshold traits are responsible for a number of inheritable phenotypic characteristics in organisms, yet their nature remains elusive and they have proven hard to study. Here we show the wing shape of Drosophila melanogaster, genetic perturbations and morphometic analysis can be used to investigate the genetic and developmental underpinnings of threshold characters. The E1 allele of the Egfr gene was used to study the genetic and developmental aspect of threshold characters. An association between a mutation in the Egfr promoter and the relative placement of the two crossveins was also re-evaluated. More than a hundred inbred strains were crossed to two strains with the same Egfr-E1 allele; strain 5144 and strain 1564. Results showed that the extra veins form in specific parts of the wing, not randomly all over and are seemingly independently of extra veins in other parts of the wing. Results also showed that cross allowed for the presence of the extra vein, and sex seemed to determine both its presence and length. The association between the Egfr polymorphism and the C region was confirmed. An association between the Egfr polymorphism and the formation of extra veins was found, however this depends on the genetic background and the sex of the individual. It was determined that the same regulatory SNP affects the continuous trait and the manifestation of a threshold trait and implicates the role of Egfr signalling in both placement of veins, and also in the formation of the vein material

The role of natural killer cells in resolution of antigen-induced inflammation

Resolution of inflammation is important in preventing chronic inflammation. Natural killer (NK) cells are known to act as the first line of defence during an infection. This study examined the role of NK cells in the resolution of antigen-induced inflammation. Mice were injected intravenously with the NK cell depleting antibody, anti-asialo GM1, or a control antibody. Prior to NK cells depletion, the mice were immunized twice subcutaneously with methylated BSA (mBSA) and 24 hours after depletion, peritonitis was induced by injecting mBSA into their peritoneum. Prior to and at several time-points following peritonitis induction, peritoneal exudates were collected, cells counted and expression of surface molecules determined by flow cytometry. Concentrations of cytokines, soluble cytokine receptors and growth factors were determined by ELISA. The NK cell depletion antibody decreased the number of NK cells in the peritoneum by 50% 36 hours after injection of the antibody (12 h after induction of inflammation). Most of the NK cells were mature, CD11b+CD27+ cells. Immature CD11b-CD27+ NK cells increased after induction of inflammation in the control group but not in the depleted group. The NK cell depletion did not affect the expression of NK cell receptors. In the control group, neutrophils increased in numbers at 6 h and reached basal levels 48 h after induction of inflammation, whereas in the depleted group the neutrophils peaked at 12 h, and were at that time-point three time higher in number than that in the control group. In addition, in the depleted group the neutrophil numbers remained high throughout the study. NK cell depletion had little effect on the number or receptor expression of other cell types. The NK cell depletion increased the concentrations and /or prolonged higher levels of IL-6, IL-12p40, G-CSF and IL-1ra. These results demonstrate that NK cells affect the inflammation process and are necessary for resolution of antigen-induced inflammation

Blágrænbakteríur í fléttum og mosum

The Nostoc cyanobacteria which belong to the order Nostocales can be found living singly or in symbiotic associations. Here we identified and cultured Nostoc and other cyanobacteria from lichens and mosses and determined if they are of related or similar strains. 11 lichens of Peltigera and Stereocaulon species and 10 samples of 5 species of mosses were collected from different locations. DNA and cultures were taken for PCR and sequencing with rbcLX primers and 16S rDNA primers. We were able to identify and culture Nostoc from the Peltigera lichens and also determine that they are of related or similar strains to each other. However, no Nostoc was identified or cultured in the Stereocaulon lichens and mosses except from one moss sample. Cyanobacteria of different genera were identified by PCR from the Stereocaulon lichens and from mosses and it was found that for each group the cyanobacteria were closely related.Blágrænbakteríur af ættkvíslinni Nostoc má finna víða, bæði útaf fyrir sig og í sambýli við aðrar lífverur. Í þessu verkefni voru greindar og ræktaðar Nostoc bakteríur og aðrar blkágrænbakteríur úr fléttum og mosum og kannað hvort þetta væru svipaðir eða skyldir stofnar. 11 fléttur af ættkvíslinni Peltigera og Stereocaulon ásamt 10 sýnum af 5 tegundum mosa var safnað á nokkrum stöðum. Erfðaefni var magnað og raðgreint úr DNA sýnum og bakteríuræktum með rbcLX og 16S rDNA vísum. Unnt var að rækta og greina Nostoc úr Peltigera sýnum og einnig að ákvarða skyldleika þeirra. Ekki var þó hægt að greina eða rækta Nostoc úr Stereocaulon eða mosasýnum neme í einu tilviki. Hægt var að nota PCR til að greina blágrænbakteríur af öðrum ættkvíslum úr Stereocaulon (grábreyskju) og úr mosasýnum og kom í ljós að fyrir hvorn hóp lífvera virtust blágrænbakteríurnar vera fremur einsleitar að skyldleika

Metabolic Response in Endothelial Cells to Catecholamine Stimulation Associated with Increased Vascular Permeability

Funding Information: Funding: This research was funded by the Icelandic Centre for Research (RANNÍS, grant number #207307051). Publisher Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Disruption to endothelial cell homeostasis results in an extensive variety of human pathologies that are particularly relevant to major trauma. Circulating catecholamines, such as adrenaline and noradrenaline, activate endothelial adrenergic receptors triggering a potent response in endothelial function. The regulation of the endothelial cell metabolism is distinct and profoundly important to endothelium homeostasis. However, a precise catalogue of the metabolic alterations caused by sustained high catecholamine levels that results in endothelial dysfunction is still under-explored. Here, we uncover a set of up to 46 metabolites that exhibit a dose–response relationship to adrenaline-noradrenaline equimolar treatment. The identified metabolites align with the glutathione-ascorbate cycle and the nitric oxide biosynthesis pathway. Certain key metabolites, such as arginine and reduced glutathione, displayed a differential response to treatment in early (4 h) compared to late (24 h) stages of sustained stimulation, indicative of homeostatic metabolic feedback loops. Furthermore, we quantified an increase in the glucose consumption and aerobic respiration in endothelial cells upon catecholamine stimulation. Our results indicate that oxidative stress and nitric oxide metabolic pathways are downstream consequences of endothelial cell stimulation with sustained high levels of catecholamines. A precise understanding of the metabolic response in endothelial cells to pathological levels of catecholamines will facilitate the identification of more efficient clinical interventions in trauma patients.Peer reviewe