The relationship between autophagy, increased neutrophil extracellular traps formation and endothelial dysfunction in chronic kidney disease

In chronic kidney disease (CKD), the number of circulating neutrophils are increased, and this is usually accompanied by an increased basal activation state. However, the possible association between neutrophil extracellular traps (NETs) with vascular complications has not been evaluated. We assessed the relationship between NETs, autophagy and endothelial dysfunction in maintenance hemodialysis (MHD) patients. NET formation, neutrophil elastase (NE) activities, and serum nucleosome levels were measured in MHD (n = 60) and controls (n = 20). Basal NET formation were markedly increased in MHD patient compared to controls. After PMA stimulation, MHD neutrophils showed significantly increased NETs formation response than controls. The degree of NETs was strongly associated with lower flow-mediated dilatation(%) of brachial artery even after adjustment for cardiovascular risk factors and uremic toxins. Moreover, MHD neutrophils showed increased basal autophagy activity. Interestingly, the levels of NETs were markedly augmented after autophagy inhibition, suggesting a protective role of autophagy in excessive NET formation.