Vitamin D Prevents Endothelial Damage Induced by Increased Neutrophil Extracellular Traps Formation in Patients with Systemic Lupus Erythematosus

Aim: to investigate the effects of Vitamin D calcitriol/1,25(OH)(2)D3 on NETosis in systemic lupus erythematosus (SLE) patients with hypovitamin D. Methods: neutrophlis of five SLE patients with hypovitamin D were divided into 4 groups, P0 (0 nM/control), P1 (1 nM), P2 (10 nM), and P3 (100 nM) as cultured samples. Phorbol Myristate Acetate (PMA) was used to stimulate NETs formation. The supernatant was separated and cocultured with HUVECs. Externalization of Neutrophil Elastase (NE) and Myeloperoxidase (MPO) during NETosis was measured by immunofluorescence and ELISA respectively. Early and late apoptosis of endothelial cell was measured by flowcytometry using cell death kit (Annexin V and PI antibody). Results: this study showed significant decrease in early apoptosis with 10 nM of 1,25(OH)(2)D3 compared to control group. Significance of NE externalization found in all treatment groups (p<0.05), while MPO absorbance in the same tendency but not statistically significant. Further analysis also found a moderate positive correlation between NE externalizations with early apoptosis. Conclusion: vitamin D 1,25(OH)(2)D3 could reduce endothelial damage by decreasing NETosis activity. This result may reveal the possibility of Vitamin D as supplementary therapy for SLE patients with hypovitamin D to prevent endothelial damage.