Open AccessOxidation of Hemoglobin Drives a Proatherogenic Polarization of Macrophages in Human Atherosclerosis
Author(s) -
József Balla,
László Potor,
Zoltán Hendrik,
Andreas Patsalos,
Éva Katona,
Gábor Méhes,
Szilárd Póliska,
Éva Csősz,
Gergő Kalló,
István Komáromi,
Zsolt Combi,
Niké Posta,
Katalin Éva Sikura,
Dávid Pethő,
Melinda Oros,
György Vereb,
Csaba Tóth,
Péter Gergely,
László Nagy,
György Balla
Publication year - 2021
Publication title -
antioxidants and redox signaling
Language(s) - English
Resource type - Journals
eISSN - 1557-7716
pISSN - 1523-0864
DOI - 10.1089/ars.2020.8234
Subject(s) - cd163 , proinflammatory cytokine , ferritin , scavenger receptor , transcriptome , foam cell , heme , downregulation and upregulation , biology , heme oxygenase , microbiology and biotechnology , pathology , chemistry , gene expression , inflammation , biochemistry , immunology , medicine , phenotype , lipoprotein , cholesterol , gene , enzyme
Aim: The aim of our study was to explore the pathophysiologic role of oxidation of hemoglobin (Hb) to ferrylHb in human atherosclerosis. Results: We observed a severe oxidation of Hb to ferrylHb in complicated atherosclerotic lesions of carotid arteries with oxidative changes of the globin moieties, detected previously described oxidation hotspots in Hb (β1Cys93; β1Cys112; β2Cys112) and identified a novel oxidation hotspot (α1Cys104). After producing a monoclonal anti-ferrylHb antibody, ferrylHb was revealed to be localized extracellularly and also internalized by macrophages in the human hemorrhagic complicated lesions. We demonstrated that ferrylHb is taken up via phagocytosis as well as CD163 receptor-mediated endocytosis and then transported to lysosomes involving actin polymerization. Internalization of ferrylHb was accompanied by upregulation of heme oxygenase-1 and H-ferritin and accumulation of iron within lysosomes as a result of heme/iron uptake. Importantly, macrophages exposed to ferrylHb in atherosclerotic plaques exhibited a proinflammatory phenotype, as reflected by elevated levels of IL-1β and TNF-α. To find further signatures of ferrylHb in complicated lesions, we performed RNA-seq analysis on biopsies from patients who underwent endarterectomies. RNA-seq analysis demonstrated that human complicated lesions had a unique transcriptomic profile different from arteries and atheromatous plaques. Pathways affected in complicated lesions included gene changes associated with phosphoinositide 3-kinase (PI3K) signaling, lipid transport, tissue remodeling, and vascularization. Targeted analysis of gene expression associated with calcification, apoptosis, and hemolytic-specific clusters indicated an increase in the severity of complicated lesions compared with atheroma. A 39% overlap in the differential gene expression profiles of human macrophages exposed to ferrylHb and the complicated lesion profiles was uncovered. Among these 547 genes, we found inflammatory, angiogenesis, and iron metabolism gene clusters regulated in macrophages. Innovation and Conclusion: We conclude that oxidation of Hb to ferrylHb contributes to the progression of atherosclerosis via polarizing macrophages into a proatherogenic phenotype. Antioxid. Redox Signal . 35, 917-950.