Role of oxidized LDL-induced “trained macrophages” in the pathogenesis of COVID-19 and benefits of pioglitazone: A hypothesis

BACKGROUND AND AIMS: Older adults and people who have cardiovascular disorders (their common pathogenetic mechanism is progressive atherosclerosis) are at higher risk for severe illness from COVID-19 (coronavirus disease 2019). Their common pathogenetic mechanism is progressive atherosclerosis in which oxLDL (oxidized LDL) plays major role. Receptor-mediated uptake of oxLDL by the monocyte-derived macrophages activates the long-term epigenetic reprogramming of innate immunity, which is termed “trained immunity.” The aim of this work is to investigate the mechanisms and treatment possibilities that can control the activities of these specific macrophages. METHODS: Search in Medline and PubMed relevant articles on the trained immunity and cytokine storm of COVID-19. RESULTS AND CONCLUSIONS: When oxLDL-trained macrophages encounter SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) in the lung, it causes unregulated cytokine secretion, leading to the alveolar damage. Therefore, blocking macrophage training by pioglitazone, a thiazolidinedione, could control the hyperactivation that the virus would trigger.