Supporting data for “Human Lipocalin-2 Variants: Therapeutic Evaluations”

Neutrophil extracellular traps (NETs) play a key role in the immune response to inflammatory stimuli but can lead to chronic inflammation when produced in excess. This study investigates the dual role of NETs in both infectious and sterile inflammation, particularly in the context of cardiovascular disease. We focused on the association of lipocalin-2 variants—specifically polyaminated lipocalin-2 (hLcn2), non-polyaminated lipocalin-2 (C87A), and highly polyaminated lipocalin-2 (R81E)—with NETs formation and inflammatory processes. Using transgenic TG-hLcn2/LKO and global lipocalin-2 knockout (LKO) mouse models, we examined the expression of these lipocalin-2 variants during high-fat dietary exposure and assessed their effects on neutrophil lifespan and phenotype.

Following a high-fat diet, our findings demonstrated that C87A levels were significantly elevated in cardiac and epididymal white adipose tissue (eWAT). Neutralization with an anti-C87A antibody effectively reduced NET formation and downregulated key inflammatory chemokines, including CXCL1 and CXCL2, which are critical for recruiting neutrophils via the CXCR4 chemokine receptor. Enhanced signalling through CXCR4 was observed in the presence of elevated C87A, correlating with increased neutrophil infiltration and NETosis, suggesting a direct link between lipocalin-2 variants and the regulation of neutrophil activity in inflammatory conditions.

Furthermore, we assessed the pathogenic role of C87A in models of obesity-induced hypertension and heart failure with preserved ejection fraction (HFpEF). Our results showed that modulation of C87A not only decreased neutrophil infiltration and NETosis but also mitigated the associated cardiovascular complications. Additionally, macrophage polarization was found to be protective against C87A-induced inflammation, while astrocytes in the brain contributed to obesity-induced hypertension through the paracrine release of inflammatory factors, including lipocalin-2.

These findings highlight the complex interplay between lipocalin-2 variants, NETs, and inflammation, suggesting that targeting lipocalin-2 variant C87A may represent a novel therapeutic strategy to mitigate chronic inflammatory conditions and their cardiovascular complications. This research underscores the importance of understanding the mechanisms underlying NETs formation and the potential for lipocalin-2 variants as therapeutic targets in managing obesity-related cardiovascular diseases.