Fig. 1

SLE patients displayed increased spontaneous NET formation and PD inhibited PMA-induced NET formation by blocking ROS production. a Neutrophils were isolated from peripheral blood of SLE patients and healthy controls (HC) and then incubated with RPMI-1640 for 4 h. Representative fluorescence microscopic images showing NETs that contained DNA (blue) and MPO (red) (× 400). White arrows indicated NETs. b Neutrophils from SLE patients spontaneously released increased NETs. NET formation was quantified by SpectraMax M3 fluorescent plate reader. c Cell viability of PD-treated neutrophils. Cell viability of neutrophils was measured by CCK-8 assay after stimulation of PD (50, 75, 100, 125 and 150 μg/mL). d Neutrophils were isolated from SLE subjects and pretreated with PD for 1 h, followed by stimulation with PMA for 30 min. Cells were stained with DCFH-DA, and the fluorescence intensity was measured. e–f Neutrophils prepared from healthy controls (HC) and SLE patients, were treated with PD for 1 h and then exposed to PMA for 4 h. NET formation was quantified as described in Materials and Methods (right). Representative fluorescence microscopic images of NET formation from HC and SLE patients are shown (× 400) on the left, respectively. For all experiments, data were shown as mean ± SD, *p < 0.05; **p < 0.01; ***p < 0.001. DAPI 4′, 6′-diamidino-2-phenylindole, HC healthy control, MPO myeloperoxidase, NET neutrophil extracellular trap, PD polydatin, PMA phorbol 12-myristate 13-acetate, SLE systemic lupus erythematosus