The Role of Protein Kinase C Isoforms in the Formation of Neutrophil Extracellular Traps

Abstract

Neutrophils release decondensed nuclear chromatin or neutrophil extracellular traps (NET) in response to a great number of physiological and pharmacological stimuli. However, apart from the host defensive function, NETs play an essential role in the pathogenesis of various autoimmune, inflammatory, and malignant diseases. Therefore, understanding the molecular mechanisms of NET formation, usually leading to the neutrophil death (NETosis), is important to control the consequences of aberrant or excessive NET release. Protein kinase C (PKC) is a serine/threonine kinase that is involved in a variety of neutrophil functions, but its role in NETosis is not well understood. Since five PKC isoforms (α, βI, βII, δ, and ζ) have been described in human neutrophils, we studied their contribution to NETosis and oxidative burst using inhibitory analysis. Using specific PKC isoform inhibitors, we have shown that PKCβ, PKCδ, and PKCζ are involved in the oxidative burst and NETosis activated by calcium ionophore A23187, while PKCβ is involved in the oxidative burst and NETosis upon cell activation by diacylglycerol mimetic phorbol 12‑myristate 13-acetate.