A perspective on NETosis in diabetes and cardiometabolic disorders.

AIMS: To review the significance of a new type of neutrophil cell death (NETosis) in diabetes and cardiometabolic diseases.

DATA SYNTHESIS: Diabetes and the metabolic syndrome are characterized by activation of the innate immune system. In this framework, neutrophils are front line defences against infections, but can also turn deleterious if abnormally stimulated. NETosis refers to a type of cell death whereby neutrophils release nuclear material and granule enzymes that together form the NETs (neutrophil extracellular traps). As NETs entrap bacteria, NETosis is instrumental to the clearance of microorganisms, but an exaggerated NETosis response can also lead to tissue damage in several pathological conditions. In diabetes, the finely tuned balance of NETosis required to protect the human body from microorganisms yet avoiding self-damage seems to be lost. In fact, in vitro induction of NETosis and circulating concentrations of NET-associated proteins appear to be enhanced in diabetic patients. Furthermore, NETs contribute to endothelial damage, thrombosis, and ischemia/reperfusion injury, making it a novel player in the pathobiology of cardiovascular disease. Though the cellular events taking place during NETosis have been described and directly visualized, its molecular machinery is still incompletely understood. Protein kinase C (PKC) and NADPH oxidase (NOX) are two important targets to counter NETosis in the setting of diabetes.

CONCLUSIONS: NETosis appears to be part of an abnormal response to damage in diabetes that, in turn, can promote or aggravate end-organ complications. We suggest that this will be a hot topic of investigation in diabetology in the near future.