Department of Pharmacology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan.
Department of Pharmacology, School of Pharmacy, Shujitsu University, Okayama 703-8516, Japan.
Oxid Med Cell Longev. 2017;2017:8419035. doi: 10.1155/2017/8419035. Epub 2017 Dec 20.
Advanced glycation end products (AGEs) are the products of a series of nonenzymatic modifications of proteins by reducing sugars. AGEs play a pivotal role in development of diabetic complications and atherosclerosis. Accumulation of AGEs in a vessel wall may contribute to the development of vascular lesions. Although AGEs have a diverse range of bioactivities, the clearance process of AGEs from the extracellular space, including the incorporation of AGEs into specific cells, subcellular localization, and the fate of AGEs, remains unclear. In the present study, we examined the kinetics of the uptake of AGEs by mouse macrophage J774.1 cells and characterized the process. We demonstrated that AGEs bound to the surface of the cells and were also incorporated into the cytoplasm. The temperature- and time-dependent uptake of AGEs was saturable with AGE concentration and was inhibited by cytochalasin D but not chlorpromazine. We also observed the granule-like appearance of AGE immunoreactivity in subcellular localizations in macrophages. Higher concentrations of AGEs induced intracellular ROS and 4-HNE, which were associated with activation of the NF-B pathway and caspase-3. These results suggest that incorporation of AGEs occurred actively by endocytosis in macrophages, leading to apoptosis of these cells through NF-B activation.
糖基化终产物（AGEs）是还原糖对蛋白质进行一系列非酶修饰的产物。AGEs 在糖尿病并发症和动脉粥样硬化的发展中起关键作用。AGEs 在血管壁中的积累可能导致血管损伤的发展。尽管 AGEs 具有广泛的生物活性，但 AGEs 从细胞外空间的清除过程，包括 AGEs 掺入特定细胞、亚细胞定位和 AGEs 的命运，仍然不清楚。在本研究中，我们检查了 AGEs 被小鼠巨噬细胞 J774.1 细胞摄取的动力学，并对其过程进行了表征。我们证明 AGEs 结合在细胞表面，并被内吞到细胞质中。AGE 的摄取随 AGE 浓度的增加呈饱和状态，可被细胞松弛素 D 但不能被氯丙嗪抑制。我们还观察到 AGE 免疫反应在巨噬细胞中的亚细胞定位中呈现颗粒样外观。较高浓度的 AGEs 诱导细胞内 ROS 和 4-HNE 的产生，这与 NF-B 途径和 caspase-3 的激活有关。这些结果表明，AGEs 通过巨噬细胞的内吞作用主动掺入，通过 NF-B 激活导致这些细胞凋亡。
