ROS and glutathionylation balance cytoskeletal dynamics in neutrophil extracellular trap formation

Abstract

Neutrophils can release their genomic DNA as extracellular traps (NETs), which ensnare bacteria and limit their replication. Stojkov et al. find that modulation of cytoskeletal dynamics by reactive oxygen species and glutathionylation controls the degranulation and release of mitochondrial DNA required for NET formation.

Chemokine-triggered microtubule polymerization promotes neutrophil chemotaxis and invasion but not transendothelial migration

“…In the present study, we have addressed these standing questions in a model of freshly isolated human neutrophils. We found that different chemotactic peptides, including the key vascular chemokine CXCL1 and the end‐target chemoattractant fMLP, triggered very slow but robust MT polymerization in these leukocytes, consistent with recent studies on fMLP‐ and C5a‐triggered neutrophils . Using a probe of real‐time tubulin polymerization, SiR‐tubulin, we found that neutrophils elongated their MTs within minutes when encountering these chemotactic peptides at their soluble states.…”

“…So far, compounds with a selective ability to interfere with MT polymerization but not with preexistent MTs have not been extensively characterized. Taxol was recently shown to interfere with MT polymerization in neutrophils primed by GM‐CSF and subsequently stimulated with C5a, a process critically dependent on the production of reactive oxidation species (ROS) and on neutrophil NADPH oxidase activity . The present study is the first to show that taxol suppresses MT polymerization triggered by both CXCL1 and fMLP, key chemotactic peptides implicated in numerous neutrophil diapedesis and interstitial migration processes underlying neutrophil recruitment to sites of infection and injury .…”

“…44,45 However, this function was so far demonstrated mainly in mesenchymal cells. In hematopoietic cells, although MTs have been implicated in a variety of effector functions including the transport of cytokine and cytotoxic cargo, 26 the direct roles of these key cytoskeletal elements in leukocyte adhesion, migration, and crossing of physiological barriers have been disputed. 17 Our present work assigns specialized functions for chemoattractant-driven MT polymerization in the ability of neutrophils to chemoattract toward the soluble chemokines and chemoattractants that induce these MT polymerization events (Table 1).…”

“…We found that different chemotactic peptides, including the key vascular chemokine CXCL1 and the end-target chemoattractant fMLP, triggered very slow but robust MT polymerization in these leukocytes, consistent with recent studies on fMLP-and C5a-triggered neutrophils. [25][26][27] Using a probe of real-time tubulin polymerization, SiR-tubulin, we found that neutrophils elongated their MTs within minutes when encountering these chemotactic peptides at their soluble states. Notably, rather than stabilizing these de novo-generated MTs, the MT binding drug taxol dramatically suppressed this slow chemoattractant-triggered MT polymerization.…”

In vivo evidence for extracellular DNA trap formation

“…ROS induces actin and tubulin glutathionylation, which is tightly regulated by glutaredoxin 1 (Grx1), an enzyme required for deglutathionylation of actin and microtubulin. Thus, an intact cytoskeleton is required for the formation of NETs 6 . Moreover, optic atrophy 1 (OPA1), one of five GTPase dynamin family members, known to play a role in mitochondrial (mt) fusion, has recently been shown to be required for ATP production through glycolysis in neutrophils.…”