Citrullination of actin-ligand and nuclear structural proteins, cytoskeleton reorganization and protein redistribution across cellular fractions are early events in ionomycin-induced NETosis

Author(s)

Reis, Lorenna Rocha ; Junior, Douglas Ricardo Souza ; Tomasin, Rebeka ; Bruni-Cardoso, Alexandre ; Di Mascio, Paolo ; Ronsein, Graziella Eliza

• Document type: Journal article
• Source: REDOX BIOLOGY; v. 64, p. 14-pg., 2023-06-23.

Abstract

Neutrophil extracellular traps (NETs) are web-like structures of DNA coated with cytotoxic proteins and histones released by activated neutrophils through a process called NETosis. NETs release occurs through a sequence of highly organized events leading to chromatin expansion and rupture of nuclear and cellular membranes. In calcium ionophore-induced NETosis, the enzyme peptidylargine deiminase 4 (PAD4) mediates chromatin decondensation through histone citrullination, but the biochemical pathways involved in this process are not fully understood. Here we use live-imaging microscopy and proteomic studies of the neutrophil cellular fractions to investigate the early events in ionomycin-triggered NETosis. We found that before ionomycin-stimulated neutrophils release NETs, profound biochemical changes occur in and around their nucleus, such as, cytoskeleton reorganization, nuclear redistribution of actin-remodeling related proteins, and citrullination of actin-ligand and nuclear structural proteins. Ionomycin-stimulated neutrophils rapidly lose their characteristic polymorphic nucleus, and these changes are promptly communicated to the extracellular environment through the secretion of proteins related to immune response. Therefore, our findings revealed key biochemical mediators in the early process that subsequently culminates with nuclear and cell membranes rupture, and extracellular DNA release. (AU)

• FAPESP's process: 13/07937-8 - Redoxome - Redox Processes in Biomedicine
• Grantee: Ohara Augusto
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 16/00696-3 - Proteomic as a tool to understand HDL function and composition
• Grantee: Graziella Eliza Ronsein
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 17/17270-1 - Study of the effect of HDL on activated neutrophils
• Grantee: Lorenna Rocha Reis
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 19/25702-4 - Understanding the effects of high density lipoprotein on human macrophages
• Grantee: Douglas Ricardo de Souza Junior
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)