[Changes in cytokine levels during foam cells formation induced by oxidized low density lipoprotein stimulation]

To investigate the alteration in levels of TNF-α, IL-1ß, IL-10, IL-12 p40 and IL-18 during foam cells formation.

human THP-1 monocytes-originated macrophages were cultured in RPMI1640 culture medium without serum for 24 h, and then were stimulated with oxidized low density lipoprotein (oxLDL) for 48 h. Foam cells formation was evaluated by oil red O staining and chemical method. Levels of TNF-α and IL-1ß in the supernatants during foam cells formation were detected by ELISA. The transcription of IL-1ß, IL-10, IL-12 p40 and IL-18 mRNAs was evaluated by real-time PCR.

81.07% macrophages were in G₀;-G₁; stage when cultured with raw RPMI1640 medium. Lipid could be obviously detected in macrophages induced by oxLDL for 48 h, and the rate of cholesterol ester to total cholesterol was over 50%. Levels of TNF-α in the supernatants reached the highest level at 12 h, and the lowest level at 48 h, IL-1ß remained at a high level at all time point. Transcription of IL-1ß, IL-10 and IL-12 p40 mRNA was enhanced at 2 h after oxLDL stimulation (P < 0.01), and transcription of IL-1ß, IL-10 and IL-18 increased significantly at 50 h compared to 2 h, whereas IL-12 decreased significantly at 50 h compared to 2 h (P < 0.01).

Cytokine levels showed an early acute inflammatory and a lately chronic anti-inflammatory process in oxLDL induced macrophages.