Figure 5. SLAMF7 mediates reduced proliferation of VSMCs in the UnS plaque. (A) Representative immunohistochemistry staining images showing lower prevalence of VSMCs compared to the CD68+ macrophages in UnS plaques than in S plaques. (B) 5 × 104 VSMCs were plated in 6-well plates, serum starved overnight, and cultured with conditioned medium (CM) from human CD14+ macrophages. Ctrl: VSMCs were treated with CM from CD14+ cells transfected with control siRNA; Ctrl+LPS: VSMCs were treated with CM from LPS stimulated control siRNA CD14+ cells; siRNA CM: VSMCs were treated with CM from SLAMF7 siRNA CD14+ cells stimulated with LPS. After 24 and 48 h, cells were harvested and counted by hemocytometer. *P < 0.05 vs. Ctrl+LPS. Each data point in all graphs represents the mean±SD of 3 independent experiments. (C) Cell cycle distribution of VSMCs treated with CM.