Localization of native high-density lipoprotein and its relation to plaque morphology in human coronary artery

High-density lipoprotein (HDL) plays a key role in reverse cholesterol transport, and halts the progression of atherosclerosis. However, its localization in human vascular wall is not well understood. We discovered that by exciting at 470-nm and emitting at 515-nm light wavelengths, Fast green dye (FG) elicits brown fluorescence characteristic of HDL only. Therefore, the localization of native HDL in normal segments and plaques in excised human coronary artery was investigated by scanning their transected surface with color fluorescent microscopy (CFM) using FG as a biomarker, and the relationships between the localization of HDL and morphology of plaques and normal segments classified by conventional angioscopy and histology were examined. The % incidence of HDL in 13 normal segments (NS) with thin (≤ 200 µm) intima, 28 NS with thick (200 µm <) intima, 41 white plaques (early stage of plaque growth), 15 yellow plaques (Y) without necrotic core (NC), and 20 Y with NC (advanced stage of plaque growth), was 30, 71 (P < 0.05 versus NS with thin intima and Y with NC), 83 (P < 0.05 versus NS with thin intima and Y with NC), 60, and 35, respectively. HDL begins to deposit in human coronary arterial wall in the early stage of atherosclerosis and deposits increase with plaque growth, but HDL decreases in plaques at an advanced stage of growth.