Department of Biochemistry, University College of Medical Sciences (University of Delhi) and GTB Hospital, Dilshad Garden, Delhi, India.
Mol Cell Biochem. 2012 Feb;361(1-2):289-96. doi: 10.1007/s11010-011-1114-9. Epub 2011 Nov 3.
Increased oxidative stress (OS) in diabetes mellitus is one of the major factors leading to diabetic pathology. However, the mediators and mechanism that provoke OS in diabetes is not fully understood, and it is possible that accumulation of advanced glycation end products (AGEs) formed secondary to hyperglycemic conditions may incite circulating polymorphonuclear neutrophils (PMN) to generate reactive oxygen species (ROS). In this report, we aim to investigate the effect of AGE on reactive oxygen and nitrogen species generation and subsequent OS in PMN. AGE-HSA exert dose- and time-dependent enhancement of ROS and reactive nitrogen intermediates (RNI) generation by PMN. Increased ROS and RNI generation were found to be mediated through the upregulation of NADPH oxidase and inducible nitric oxide synthase (iNOS), respectively, as evident from the fact that AGE-treated neutrophils failed to generate ROS and RNI in presence of diphenyleneiodonium, a flavoprotein inhibitor for both enzymes. Further increased generation of ROS and RNI ceased when the cells were incubated with anti-RAGE antibody suggesting the involvement of AGE-RAGE interaction. Also increased malondialdehyde (MDA) and protein carbonyl formation in AGE-exposed PMN suggest induction of OS by AGE. This study provides evidence that AGEs may play a key role in the induction of oxidative stress through the augmentation of PMN-mediated ROS and RNI generation and this may be in part responsible for development of AGE-induced diabetic pathology.
在糖尿病中，氧化应激（OS）的增加是导致糖尿病病理的主要因素之一。然而，导致糖尿病中 OS 的介质和机制尚未完全了解，并且可能是由于高血糖条件下形成的晚期糖基化终产物（AGEs）的积累，可能会引发循环多形核白细胞（PMN）产生活性氧（ROS）。在本报告中，我们旨在研究 AGE 对 PMN 中活性氧和活性氮物种生成及随后的 OS 的影响。AGE-HSA 可剂量依赖性地增强 PMN 中 ROS 和活性氮中间体（RNI）的生成，时间依赖性增强。ROS 和 RNI 的生成增加是通过 NADPH 氧化酶和诱导型一氧化氮合酶（iNOS）的上调介导的，这一点从事实中显而易见，即在用二苯并碘鎓处理的中性粒细胞中，这两种酶的黄素蛋白抑制剂，PMN 无法生成 ROS 和 RNI。当用抗 RAGE 抗体孵育细胞时，ROS 和 RNI 的生成进一步增加停止，表明 AGE-RAGE 相互作用的参与。AGE 暴露的 PMN 中丙二醛（MDA）和蛋白质羰基形成的增加也表明 AGE 诱导 OS。这项研究提供了证据，表明 AGEs 通过增强 PMN 介导的 ROS 和 RNI 的生成，可能在诱导氧化应激中发挥关键作用，这可能是 AGE 诱导的糖尿病病理发生的部分原因。
