Fig. 2: GAPDH inhibition promotes neutrophil extracellular trap formation.

a Diagram of the GAPDH reaction. b The DHAP/BPG ratio in neutrophils from COVID-19 patients and healthy controls. Violin plot lines represent median and interquartile range. c, d Effect of HA or PMA on Sytox Green fluorescent signal intensity in primary human neutrophils. A representative trace (c) and quantitation of independent experiments (d) are shown. In (d) datapoints represent human donor neutrophil samples from n = 18 independent experiments, tested twice/experiment, from a total of n = 8 human donors. Some of these experiments included other treatments described subsequently in the paper. HA Heptelidic acid, PMA Phorbol 12-myristate 13-acetate. e, f Time-lapse images of the effects of HA, PMA, or A23187 on NET formation. e shows magnified images of 4 timepoints, and f, g show larger fields of view at different timepoints. e, f were acquired with, and g without, the brightfield channel. Representative images from n = 22 independent experiments for HA, n = 14 for PMA treatment, and n = 3 for A23187 treatment. h, i Neutrophil elastase staining after HA, PMA, or A23187 treatment. Panel i shows a magnification from h. Representative images from four independent experiments. Data represent median and interquartile range (b), mean ± s.e.m. (c), mean ± st.dev. (d). Statistical significance was assessed with one-way ANOVA followed by multiple comparisons correction (b) or one-way ANOVA with Brown–Forsythe correction and Dunnett’s T3 multiple comparisons test (d).