Sakamoto T, Hinton D R, Kimura H, Spee C, Gopalakrishna R, Ryan S J
Doheny Eye Institute, Los Angeles, CA 90033, USA.
Graefes Arch Clin Exp Ophthalmol. 1996 Mar;234(3):186-92. doi: 10.1007/BF00462031.
Retinal pigment epithelial (RPE) cells play an important role in proliferative vitreoretinopathy (PVR). Vitamin E succinate is an ester form of a potent biological antioxidant, vitamin E, and has unique effects on various cells. We examined the effect of vitamin E succinate on proliferation and migration of cultured bovine RPE cells, since these are critical steps in the development of PVR.
Bovine RPE cells were cultured in minimal essential medium (MEM) containing 10% fetal calf serum (MEM-10). Cells were incubated with MEM-10 containing 25 microM vitamin E, vitamin E succinate, butylated hydroxytoluene (BHT) or d-mannitol. Cell proliferation was assessed by counting cell numbers on days 2, 4 and 6. 3H-Thymidine uptake was also examined in RPE cells incubated with various forms of vitamin E-- vitamin E, vitamin E succinate, Trolox, gamma-tocopherol, vitamin E acetate, vitamin E phosphate, vitamin E nicotinate--or antioxidants-- BHT or d-mannitol (25 microM each). RPE cell migration was studied as follows: A small area (5 x 15 mm) of confluent cultured RPE cells was denuded using a straight razor blade and incubation was continued for 20 h with MEM-10 containing vitamin E, vitamin E succinate, gamma-tocopherol or BHT. The number of cells that migrated into the denuded area from the wound edge in each microscopic field (x20) was counted and expressed as a percentage of control (MEM-10 alone).
The antioxidants, vitamin E and BHT, stimulated RPE cell proliferation and 3H-thymidine incorporation compared with the control, while vitamin E succinate significantly inhibited both proliferation and 3H-thymidine uptake (IC50, 23 microM). Other forms of vitamin E or d-mannitol had no effect. Neither vitamin E nor BHT had a significant effect on RPE cell migration (108.2% and 112.6% of control, respectively), but vitamin E succinate inhibited migration (58.3%). Cell viability, assessed by the trypan blue dye exclusion test, was not impaired by a 3-day incubation with 50 microM of vitamin E succinate.
An ester form of a physiological antioxidant, vitamin E succinate, inhibits RPE cell proliferation and migration without causing cellular toxicity. These findings suggest its therapeutic potential for the pharmacological treatment of PVR.
视网膜色素上皮（RPE）细胞在增殖性玻璃体视网膜病变（PVR）中起重要作用。维生素E琥珀酸酯是一种强效生物抗氧化剂维生素E的酯形式，对各种细胞具有独特作用。我们研究了维生素E琥珀酸酯对培养的牛RPE细胞增殖和迁移的影响，因为这些是PVR发展中的关键步骤。
牛RPE细胞在含有10%胎牛血清的最低必需培养基（MEM）（MEM-10）中培养。细胞与含有25 microM维生素E、维生素E琥珀酸酯、丁基羟基甲苯（BHT）或D-甘露醇的MEM-10一起孵育。在第2、4和6天通过计数细胞数量评估细胞增殖。还在与各种形式的维生素E（维生素E、维生素E琥珀酸酯、生育酚、γ-生育酚、维生素E醋酸酯、维生素E磷酸盐、维生素E烟酸盐）或抗氧化剂（BHT或D-甘露醇，各25 microM）孵育的RPE细胞中检测3H-胸腺嘧啶核苷摄取。RPE细胞迁移研究如下：使用直剃须刀片刮除汇合培养的RPE细胞的一小片区域（5×15 mm），并继续与含有维生素E、维生素E琥珀酸酯、γ-生育酚或BHT的MEM-10孵育20小时。计数每个显微镜视野（×20）中从伤口边缘迁移到刮除区域的细胞数量，并表示为对照（仅MEM-10）的百分比。
与对照相比，抗氧化剂维生素E和BHT刺激RPE细胞增殖和3H-胸腺嘧啶核苷掺入，而维生素E琥珀酸酯显著抑制增殖和3H-胸腺嘧啶核苷摄取（IC50，23 microM）。其他形式的维生素E或D-甘露醇没有作用。维生素E和BHT对RPE细胞迁移均无显著影响（分别为对照的108.2%和112.6%），但维生素E琥珀酸酯抑制迁移（58.3%）。通过台盼蓝染料排除试验评估的细胞活力，在与50 microM维生素E琥珀酸酯孵育3天时未受损。
生理抗氧化剂维生素E的酯形式维生素E琥珀酸酯抑制RPE细胞增殖和迁移而不引起细胞毒性。这些发现提示其在PVR药物治疗中的治疗潜力。
