Background: The macrophage polarization is proposed to be involved in initial events
and remodeling of atherosclerosis plaques. Mannose receptor, C type 1 (MRC1) is a trans-membrane
glycoprotein participating in phagocytosis and, is highly expressed in the M2 macrophages.
Objective: The aim of this study was to investigate the effects of sdLDL (small dense LDL) on the
MRC1 gene expression level and secretion of histamine in the differentiated M2 macrophages from
monocytes of patients with coronary artery stenosis and healthy subjects.
Method: The monocytes were isolated from healthy subjects (< 5% stenosis) and patients (>70%
stenosis, SVD (Single Vessel Disease), 2VD (Two-Vessel Disease) and 3VD (Three-Vessel
Disease)) by RosetteSep kit and, were differentiated into M2 macrophages by macrophage colonystimulating
factor (M-CSF). The sdLDL particles were obtained by PEG-combined precipitation
method. The MRC1 gene expression and histamine levels were measured by RT-qPCR and ELISA
Results: The MRC1 gene expression level was significantly increased in M2 macrophages of
healthy subjects (P=0.05) while it reduced in SVD (P=0.05), 2VD (P=0.01) and 3VD (P=0.9)
patients after treatment with sdLDL. The histamine value secreted from M2 macrophages (7-day)
was higher (>3-fold, P=0.02) in patients as compared to healthy controls.
Conclusion: The results showed that the sdLDL particles reduce the MRC1 gene expression levels
in the differentiated M2 macrophages from patients with coronary artery disease. Furthermore, they
had high inflammatory capacity for the secretion of histamine.