Figure 3.

Foam cell formation assay using macrophage-specific plasmid vector. (a) RAW264.7 cells were transfected with a plasmid vector and treated with oxLDL (100 μg ml⁻¹) for 24 h. Lipid depositions of control, oxLDL alone, CMV-APN+oxLDL and SP-APN+oxLDL were detected 24 h later by oil red O staining and observed under an optical microscope at × 200 magnification. Absorbance of oil red O was detected by spectrophotometer at 518 nm and normalized to that obtained with the control group. (b) Released APN protein in the cultured media was higher in SP-APN-transfected cells than in CMV-APN-transfected cells. Data shown are means±s.d.'s. *P<0.05, **P<0.01 and ***P<0.001. APN, adiponectin.