Citrullinated histone H3 (CitH3) on neutrophil extracellular traps (CitH3)

Citrullinated histones, particularly Citrullinated Histone H3 (CitH3), are essential structural and functional components of Neutrophil Extracellular Traps (NETs) and related extracellular chromatin structures. These structures are formed when neutrophils undergo a specialized form of cell death called NETosis, during which the enzyme Peptidylarginine Deiminase 4 (PAD4) citrullinates histones to facilitate massive chromatin decondensation and subsequent release into the extracellular space (Wang et al., 2009, J Cell Biol). While NETs are intended to trap and kill invading pathogens, their persistence and the presence of extracellular citrullinated histones are highly cytotoxic and pro-thrombotic, contributing to the pathogenesis of sepsis, autoimmune diseases like rheumatoid arthritis, and cancer metastasis (Li et al., 2010, J Exp Med; Thålin et al., 2017, PLoS ONE). In clinical settings, CitH3 serves as a specific biomarker for NETosis and is associated with poor outcomes in inflammatory and infectious conditions (Zuo et al., 2020, JCI Insight). Therapeutic strategies targeting this entity include the use of PAD4 inhibitors to prevent NET formation, DNase I to degrade the DNA scaffold, and monoclonal antibodies designed to neutralize the toxic effects of extracellular citrullinated histones directly. These interventions aim to reduce tissue damage and immunothrombosis without severely compromising the broader immune system. Monitoring CitH3 levels also serves as a valuable biomarker for disease severity and treatment response in inflammatory and infectious diseases.

Other names

CitH3Citrullinated histone 3NET-associated citrullinated histonesExtracellular citrullinated chromatinCitrullinated histones on neutrophil extracellular traps and related extracellular chromatin structures

Inhibition of Peptidylarginine deiminase 4 (PAD4) to prevent histone citrullination and NET release; enzymatic degradation of the DNA scaffold by DNase; direct neutralization of extracellular citrullinated histones by monoclonal antibodies to prevent cytotoxicity and thrombosis.