Cardiovascular research institute, Isfahan University of Medical Sciences ARYA Atherosclerosis Journal 1735-3955 19 1 2023 01 01 The effect of ox-LDL and platelets on macrophages, M2 macrophage polarization, and foam cell formation 25 33 26114 10.48305/arya.2022.11777.2422 EN Fatemeh Barati Department of Hematology and Blood Banking, School of Allied Medical Sciences Shahid Beheshti University of Medical Sciences, Tehran, Iran Davood Bashash Department of Hematology and Blood Banking, School of Allied Medical Sciences Shahid Beheshti University of Medical Sciences, Tehran, Iran Mohamad Hosein Mohamadi HSC Research Center-Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical sciences, Tehran, Iran Mahdieh Mehrpori Department of Laboratory Sciences, School of Allied Medical Sciences Alborz University of Medical Sciences, Karaj, Iran Mohsen Hamidpour HSC Research Center-Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical sciences, Tehran, Iran 0000-0002-3658-1551 Journal Article 2021 04 19 Background: The accumulation of oxidized LDL (ox-LDL) in macrophages in association with platelet activity leads to the formation of foam cells, which play a key role in the pathophysiology of atherosclerosis and coronary artery diseases (CAD). Here, in this study, we aimed to investigate the simultaneous effect of ox-LDL and platelets on foam cell formation, as well as modification in cell markers. <br />Methods: First, the U937, a human monocytic cell line,  was cultured in RPMI-1640. Then, isolated platelets were co-cultured with the U937 and exposed to ox-LDL (80 µg/ml) to evaluate the impact of ox-LDL on foam cell formation using Oil red O (ORO) staining. Also, the expression of foam cells’ surface markers and CD36, ABCA1, SR-B1, ACAT1, and LXRα genes, which are involved in macrophage metabolism and ox-LDL uptake, was measured by flow cytometry and real-time PCR, respectively. <br />Results: Our findings suggest that platelets promoted foam cell formation (ORO-positive cells), accompanied by a higher level of CD163+ M2 macrophages. Furthermore, the expression of CD36, ABCA1, SR-B1, ACAT1, and LXRα genes, which are implicated in cholesterol accumulation in macrophages, was significantly upregulated in the ox-LDL+ platelets group compared to the control (P < 0.05). Moreover, the up-regulation of CD36, ABCA1, and SR-B1 genes in the ox-LDL+ platelets group was more accentuated compared to the ox-LDL group (P < 0.05).<br />Conclusions: Owing to the positive effector role of platelets in the formation of foam cells and CD163+ cells, it could be assumed that platelets play a dual role in the development of these cells. https://arya.mui.ac.ir/article_26114_f6370bef326f11083c0fc214d6d01d12.pdf