Redox modulation by a synthetic thiol compound reduces LPS-induced pro-inflammatory cytokine expression in macrophages via AP-1/NLRP3 axis and influences the crosstalk with endothelial cells

Perturbation in redox status elicits multiple cellular pathways, including those involved in the inflammatory response. A thiol-based molecule (I-152), releasing N-acetyl-cysteine (NAC) and β-mercaptoethylamine (MEA), was exploited as a redox-modulating agent, and its effects on pro-inflammatory cytokine expression and secretion in lipopolysaccharide (LPS)-stimulated macrophages (MΦ) were investigated. I-152 inhibited cytokine gene expression as well as protein secretion of the most important inflammatory cytokines in three different MΦ models <i>in vitro</i> and <i>ex vivo</i>. It alleviated inflammation <i>via</i> the c-Jun/AP-1 and NF-κB signaling pathways, depending on the dose, and regulated NLRP3 inflammasome expression, leading to decreased IL-1β and IL-18 release and reduced pyroptotic cell death. Consequently, the influence of redox-modulated MΦ secretome on the crosstalk with endothelial cells was evaluated. Co-culture experiments between THP-1 MΦ, that had been pretreated with I-152 before LPS stimulation, and Human Vascular Endothelial Cells (HUVECs) showed reduced VCAM/ICAM expression in these cells in concomitance with a less oxidized and inflamed MΦ proteomic portrait. Overall, our findings suggest that I-152 redox modulation could target the AP-1/NLRP3 axis, affecting LPS-induced inflammation in MΦ and influencing HUVEC responses, revealing a complex and bidirectional interchange. Thiol redox homeostasis is a key factor for the development of a balanced immune response.Excessive ROS are critical effectors of NLRP3 inflammasome.Redox modulation by a synthetic thiol compound (I-152), releasing N-acetyl-cysteine (NAC) and β-mercaptoethylamine (MEA), affects pro-inflammatory cytokine production in LPS-stimulated macrophages.I-152 mitigates inflammation via the c-Jun/AP-1 and NF-κB pathways and modulates NLRP3 inflammasome expression in LPS-stimulated macrophages.I-152-mediated redox modulation in macrophages modulates macrophage/endothelial cell cross-talk. Thiol redox homeostasis is a key factor for the development of a balanced immune response. Excessive ROS are critical effectors of NLRP3 inflammasome. Redox modulation by a synthetic thiol compound (I-152), releasing N-acetyl-cysteine (NAC) and β-mercaptoethylamine (MEA), affects pro-inflammatory cytokine production in LPS-stimulated macrophages. I-152 mitigates inflammation via the c-Jun/AP-1 and NF-κB pathways and modulates NLRP3 inflammasome expression in LPS-stimulated macrophages. I-152-mediated redox modulation in macrophages modulates macrophage/endothelial cell cross-talk.