Fig. 5: Condensation reverses the inhibition by heparin or spermine on TNF-triggered endothelial activation.
From: Mast cell extracellular granules are bioactive condensates assembled by heparin and polyamine
a, Fluorescence images of 100 nM AF488-labeled TNF (green) in the presence of 50 μM heparin (premixed with 2 μM Cy5-labeled heparin; magenta) or 1 mM spermine or in heparin–spermine condensates. Scale bar, 10 μm. b, Bright-field and fluorescence images of HUVECs after 24 h of treatment with AF488-labeled TNF (1 ng, green) in PBS buffer or in heparin–spermine condensates. Hep, heparin; Spm, spermine. Scale bar, 10 μm. c–e, HUVECs were treated with 1 ng of AF488-labeled TNF in PBS buffer combined with heparin and spermine or in heparin–spermine condensates. c, The mean fluorescence intensity of AF488-labeled TNF on HUVECs and the percentage of AF488-labeled TNF-positive cells after 1 h and 24 h were analyzed by flow cytometry. P values were determined using a two-way ANOVA test with Tukey’s multiple-comparison test. d, Surface ICAM1 expression on HUVECs was analyzed by flow cytometry. P values were determined using an ordinary one-way ANOVA test with Tukey’s multiple-comparison test. e, CCL2 levels in the cell supernatant were measured by ELISA (n = 3 biological replicates). P values were determined using an ordinary one-way ANOVA test with Dunnett’s multiple-comparison test. Data are presented as the mean ± s.d. One representative of three independent experiments is shown.
