Nanoformulated omega-3-rich linseed oil reverses ex vivo the phenotype of monocytes of hemodialysis patients from a pro into an anti-inflammatory one with attenuated ROS formation and cell activation
G Lima, H Muzammel, A Mroueh, S Amissi, E Tureli, P Kerth, M Schneider, N Florens, S Caillard-Ohlmann, F C F Brito, V B Schini-KerthAbstract
Introduction
Patients undergoing maintenance hemodialysis (HD) have markedly increased cardiovascular risk, with cardiovascular disease as the leading cause of death in this population. Chronic systemic inflammation, immune dysregulation involving monocytes/macrophages, and metabolic disturbances contribute to endothelial dysfunction, oxidative stress, vascular injury, and thrombosis. Omega-3 polyunsaturated fatty acids (PUFAs) can attenuate inflammation and promote its resolution. In a hemodialysis cohort, omega-3 PUFA supplementation has been associated with a substantial reduction in major cardiovascular events. Nevertheless, the precise mechanisms underlying these benefits remain unclear.
Purpose
Evaluate the impact of stabilized nanoformulated (NF) linseed oil (25% w/w) containing 13.75% (w/w) alpha linolenic acid (plant-derived omega-3 PUFAs) on activated monocytes from HD patients as compared to healthy donors.
Methods
Monocytes isolated from freshly collected blood samples of either healthy donors (n=10) or HD patients (n=15) were studied. Levels of reactive oxygen species (ROS) formation were quantified using dihydroethidium (DHE) staining, and nitrotyrosine levels by immunofluorescence. Genes expression of markers of oxidative stress, inflammation, macrophages polarization and pro-coagulant responses were evaluated using RT-qPCR. NF corn oil was used as a control oil.
Results
Monocytes isolated from HD patients displayed a markedly pro-oxidative and pro-inflammatory phenotype, characterized by a 2.5-fold increase in ROS production compared with healthy controls, and accompanied by a 1.6-fold elevation in glucose uptake. The pro-oxidant response involved pro-inflammatory cytokines and NADPH oxidases as evidence by the inhibitory effect of neutralization of TNF-α and the NADPH oxidase inhibitor VAS-2780, respectively. Treatment of HD activated monocytes with NF linseed oil (0.0003-0.003% w/w) for 24 h effectively mitigated in a concentration-dependent manner the formation of ROS by about 84% whereas NF corn oil was inactive. In addition, NF linseed oil treatment of HD activated monocytes reduced the expression level of pro-inflammatory markers (TNF-α, iNOS, CD86), markers of oxidative stress (NOX2, nitrotyrosine) and thrombotic responses (tissue factor), and promoted the expression of anti-inflammatory markers (CD163 and CD206).
Conclusion
Monocytes from maintenance hemodialysis patients display a constitutively activated, pro-inflammatory, pro-oxidative, and pro-thrombotic phenotype, with upregulation of TNF-α, NADPH oxidases, and tissue factor. Omega-3 PUFA-rich NF linseed oil reverses this phenotype, shifting monocytes towards an anti-inflammatory, anti-oxidative, and anti-thrombotic profile, consistent with beneficial metabolic responses. NF linseed oil therefore represents a promising approach to attenuate inflammation-driven cardiovascular risk in HD patients, which remains to be clinically validated.