Figure 1. Characteristics of [¹⁴C]α-tocopherol-high-density lipoprotein uptake and scavenger receptor class B, type I protein expression in TR-iBRB2 cells

A: [¹⁴C]α-tocopherol-high density lipoprotein (HDL) uptake by TR-iBRB2 cells exhibited a time-dependent increase and a temperature-dependence. The [¹⁴C]α-tocopherol-HDL (10 μM of [¹⁴C]α-tocopherol) uptake was performed at 37 °C (circle) or 4 °C (square). Each point represents the mean±SEM (n=4). B: The [¹⁴C]α-tocopherol-HDL uptake was inhibited by block lipid transport-1 (BLT-1), a potent inhibitor of SR-BI, in a concentration dependent manner with an IC₅₀ of 23.2 nM. Each point represents the mean±SEM (n=4). Asterisk (*) and double asterisk (**) represent statistical significance of differences from control, *p<0.01 and **p<0.05, respectively. C: Immunoblot analysis of SR-BI was performed using mouse liver (lane 1), membrane fraction of TR-iBRB2 cells (lane 2), and whole lysate of TR-iBRB2 cells (lane 3). Mouse liver was used as a positive control. D-F: SR-BI immunoreactivities were detected in rat retinal capillary endothelial cells by immunofluorescence. Rat retina was stained with anti-SR-BI antibody (red; D, E) and anti-GLUT1 antibody (green, E, F). Scale bars represents 5 μm.