Possible new role of vascular endothelial growth factor-D during the acute phase of Kawasaki disease

Neutrophil extracellular trap from Kawasaki disease alter the biologic responses of PBMC

Kawasaki disease (KD), also known as mucocutaneous lymph node syndrome, is an acute systemic vasculitis syndrome that mainly occurs in infants under 5 years of age. In the current manuscript, we were aiming to analyze the role of neutrophil extracellular traps (NETs) in the pathogenesis of KD, especially their interplay with peripheral blood mononuclear cells (PBMCs). Neutrophils were exposed to 20 nM phorbol myristate acetate (PMA), we found that neutrophils of KD patients were more likely to form NETs compared with healthy controls (HCs). Furthermore, PBMCs were cultured with NETs for 24 h, and we observed that NETs significantly increased the cell viability, suppressed cell apoptosis, and enhanced the pro-inflammatory cytokines production and NF-κB activation in PBMCs from KD patients. In addition, with the stimulation of NETs, the expression of vascular endothelial growth factor A (VEGF-A) and hypoxia-inducible factor-1α (HIF-1α) were increased, which were related with the pathological mechanism of KD. At last, we examined the activation of phosphoinositide 3 kinase (PI3K)/Akt signaling, and we found NETs treatment obviously enhanced the activation of PI3K and Akt. In conclusion, these findings suggested that the formation of NETs may alter the biologic responses of PBMC and affect the vascular injury in KD.

Regulation and implications of inflammatory lymphangiogenesis

Lymphatic vessels (LVs) are highly dynamic structures that intimately interact with their surrounding microenvironment. They have a profound influence on the immune system and therefore can manipulate inflammatory processes. Inflammation is a major cause of adulthood lymphangiogenesis and LV remodeling. In turn, LVs can reciprocally manipulate inflammatory processes. For instance, LV growth and/or activation regulate antigen presentation and inflammatory cell recruitment to lymph nodes (LNs), and therefore critically affect adaptive immunity. The vascular endothelial growth factor (VEGF)-C-VEGF receptor-3 and VEGF-A-VEGF receptor-2 signaling pathways are particularly important in inflammatory lymphangiogenesis. LVs contribute to the pathophysiology of various inflammatory conditions. Knowledge of lymphatic biology can be applied to manipulate inflammatory disorders and divert immune responses. This review summarizes basic concepts of inflammation-relevant lymphatic biology, and describes recent progress and practical implications.