Netosis, Myeloperoxidase and Halogenative Stress: Interrelationship and Role in Pathology

This review offers an analysis of the signaling pathways for suicidal and vital NETosis, with a focus on myeloperoxidase and the reactive halogen species generated in the reactions it catalyzes. We also consider the diversity of neutrophil extracellular traps formed through NETosis and capable of performing both protective (bactericidal) and pathological (proinflammatory) functions. Particular attention is paid to the mechanisms by which myeloperoxidase, released from azurophilic granules during NETosis, facilitates halogenative stress in non-infectious diseases accompanied by inflammation. The interconnection between NETosis and halogenative stress is demonstrated. On the one hand, in halogenative stress, reactive halogen species and products of their reactions with biomolecules stimulate neutrophils to trigger NETosis. On the other hand, active myeloperoxidase within neutrophil extracellular traps or released during their destruction produces reactive halogen species, promoting the development of halogenative stress.