prostaglandin-d2 and sphingosine-1-phosphate

Endothelial 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.

Topics: Biomarkers; Cell Line; Chromatography, High Pressure Liquid; Endothelial Cells; Fatty Acids; gamma-Aminobutyric Acid; Glycocalyx; Human Umbilical Vein Endothelial Cells; Humans; Interferon-gamma; Kynurenine; Lipopolysaccharides; Lysophospholipids; Metabolome; Models, Biological; Nitric Oxide; Permeability; Polysaccharides; Prostaglandin D2; Sepsis; Sphingosine; Survival Analysis; Tryptophan

Sphingosine-1-phosphate (S1P) has been shown to be involved in the asthmatic disease as well in preclinical mouse experimental models of this disease. The aim of this study was to understand the mechanism(s) underlying S1P effects on the lung.. BALB/c, mast cell-deficient and Nude mice were injected with S1P (s.c.) on days 0 and 7. Functional, molecular and cellular studies were performed.. S1P administration to BALB/c mice increased airway smooth muscle reactivity, mucus production, PGD2 , IgE, IL-4 and IL-13 release. These features were associated to a higher recruitment of mast cells to the lung. Mast cell-deficient Kit (W) (-sh/) (W) (-sh) mice injected with S1P did not display airway smooth muscle hyper-reactivity. However, lung inflammation and IgE production were still present. Treatment in vivo with the anti-CD23 antibody B3B4, which blocks IgE production, inhibited both S1P-induced airway smooth muscle reactivity in vitro and lung inflammation. S1P administration to Nude mice did not elicit airway smooth muscle hyper-reactivity and lung inflammation. Naïve (untreated) mice subjected to the adoptive transfer of CD4+ T-cells harvested from S1P-treated mice presented all the features elicited by S1P in the lung.. S1P triggers a cascade of events that sequentially involves T-cells, IgE and mast cells reproducing several asthma-like features. This model may represent a useful tool for defining the role of S1P in the mechanism of action of currently-used drugs as well as in the development of new therapeutic approaches for asthma-like diseases.

Topics: Animals; Bronchial Hyperreactivity; CD4-Positive T-Lymphocytes; Immunoglobulin E; Interleukin-13; Interleukin-4; Lysophospholipids; Mast Cells; Mice, Inbred BALB C; Mice, Knockout; Mice, Nude; Pneumonia; Prostaglandin D2; Sphingosine