Department of Ophthalmology, Qilu Hospital, Shandong University, 107#, Wenhua Xi Road, Jinan, 250012, People's Republic of China.
Mol Cell Biochem. 2013 Nov;383(1-2):253-9. doi: 10.1007/s11010-013-1773-9. Epub 2013 Aug 18.
Delayed healing of corneal epithelial wounds is a serious complication in diabetes. Advanced glycation end products (AGEs) are intimately associated with the diabetic complications and are deleterious to the wound healing process. However, the effect of AGEs on corneal epithelial wound healing has not yet been evaluated. In the present study, we investigated the effect of AGE-modified bovine serum albumin (BSA) on corneal epithelial wound healing and its underlying mechanisms. Our data showed that AGE-BSA significantly increased the generation of intracellular ROS in telomerase-immortalized human corneal epithelial cells. However, the generation of intracellular ROS was completely inhibited by antioxidant N-acetylcysteine (NAC), anti-receptor of AGEs (RAGE) antibodies, or the inhibitor of NADPH oxidase. Moreover, AGE-BSA increased NADPH oxidase activity and protein expression of NADPH oxidase subunits, p22phox and Nox4, but anti-RAGE antibodies eliminated these effects. Furthermore, prevention of intracellular ROS generation using NAC or anti-RAGE antibodies rescued AGE-BSA-delayed epithelial wound healing in porcine corneal organ culture. In conclusion, our results demonstrated that AGE-BSA impaired corneal epithelial wound healing ex vivo. AGE-BSA increased intracellular ROS generation through NADPH oxidase activation, which accounted for the delayed corneal epithelial wound healing. These results may provide better insights for understanding the mechanism of delayed healing of corneal epithelial wounds in diabetes.
角膜上皮伤口愈合延迟是糖尿病的一种严重并发症。晚期糖基化终产物（AGEs）与糖尿病并发症密切相关，对伤口愈合过程有害。然而，AGEs 对角膜上皮伤口愈合的影响尚未得到评估。在本研究中，我们研究了 AGE 修饰的牛血清白蛋白（BSA）对角膜上皮伤口愈合的影响及其潜在机制。我们的数据表明，AGE-BSA 可显著增加端粒酶永生化人角膜上皮细胞内的细胞内 ROS 生成。然而，抗氧化剂 N-乙酰半胱氨酸（NAC）、AGEs 受体（RAGE）抗体或 NADPH 氧化酶抑制剂完全抑制了细胞内 ROS 的生成。此外，AGE-BSA 增加了 NADPH 氧化酶活性和 NADPH 氧化酶亚基 p22phox 和 Nox4 的蛋白表达，但抗 RAGE 抗体消除了这些作用。此外，使用 NAC 或抗 RAGE 抗体预防细胞内 ROS 的产生可挽救猪角膜器官培养中 AGE-BSA 延迟的上皮伤口愈合。总之，我们的结果表明，AGE-BSA 损害了体外角膜上皮伤口愈合。AGE-BSA 通过 NADPH 氧化酶的激活增加了细胞内 ROS 的产生，这是导致角膜上皮伤口愈合延迟的原因。这些结果可能为理解糖尿病角膜上皮伤口愈合延迟的机制提供更好的认识。
