a Effect of AIBP and HDL3 on lipid rafts of HRMECs. Cells were stained for lipid rafts (green, D4-EGFP) and nuclei (blue, DAPI) after preincubation with control media, AIBP, HDL3, or AIBP plus HDL3. b Quantification of the area of lipid rafts per cell. N = 92, 54, 70, and 86 cells for control, AIBP, HDL3, and AIBP + HDL3, respectively. c Effect of AIBP and HDL3 on endothelial cell tube formation using the Matrigel-based assay. The total segment length of HRMEC tubes was quantified after various treatments. N = 12, 9, 6, 6, and 6 for control, AIBP, HDL3, AIBP + HDL3, and MβCD, respectively. Representative images (d) and quantification of microvascular sprouting area (e) after AIBP treatment. N = 3 explants per group. Data represent mean ± SEM in b, c, e. Statistical analysis was performed by one-way ANOVA with Tukey post hoc analysis (b, c) or two-tailed Student’s t-test (e).