Cia David, Bonhomme Brigitte, Azaïs-Braesco Véronique, Cluzel Jacques, Doly Michel
Laboratoire de Biophysique Sensorielle, Facultés de Médecine et de Pharmacie, Université d'Auvergne, Clermont-Ferrand, France.
Vision Res. 2004 Feb;44(3):247-55. doi: 10.1016/j.visres.2003.09.017.
We investigated the capacity of Royal College of Surgeons (RCS) rat retinal pigment epithelial (RPE) cells to take up all-trans-retinol (ROL) (vitamin A) and to metabolize it into retinyl esters (RE). Cultures of RPE cells were established from RCS and control newborn rats. All-trans-ROL was delivered to the apical surface of the RPE monolayer. Retinoids were analyzed by high-performance liquid chromatography. The cellular retinol-binding protein type I (CRBP-I) was assessed by Western blotting. Before supplementation with ROL, RE were lower in RCS rats. After ROL supplementation, esters increased and reached values that were similar in the two strains, but the increase, expressed relative to the initial value, was higher in RCS rats. The uptake of ROL and the level of CRBP-I were greater in RCS rats. Our results provide evidence of a functional retinol esterifying enzyme in cultured RCS RPE cells and suggest that CRBP-I could play a role in the uptake and esterification of ROL in the RPE cells.
我们研究了皇家外科医学院（RCS）大鼠视网膜色素上皮（RPE）细胞摄取全反式视黄醇（ROL，维生素A）并将其代谢为视黄酯（RE）的能力。从RCS和对照新生大鼠建立RPE细胞培养物。将全反式ROL递送至RPE单层的顶端表面。通过高效液相色谱法分析类视黄醇。通过蛋白质免疫印迹法评估I型细胞视黄醇结合蛋白（CRBP-I）。在补充ROL之前，RCS大鼠中的RE较低。补充ROL后，酯类增加并达到两种品系中相似的值，但相对于初始值的增加在RCS大鼠中更高。RCS大鼠中ROL的摄取和CRBP-I的水平更高。我们的结果提供了培养的RCS RPE细胞中存在功能性视黄醇酯化酶的证据，并表明CRBP-I可能在RPE细胞中ROL的摄取和酯化中发挥作用。
