Basta Giuseppina, Del Turco Serena, De Caterina Raffaele
Istituto di Fisiologia Clinica, CNR, Pisa.
Recenti Prog Med. 2004 Feb;95(2):67-80.
The formation of advanced glycation endproducts (AGEs) is an important biochemical abnormality accompanying diabetes mellitus and, likely, inflammation in general. Here we summarize and discuss recent studies indicating that the effects of AGEs on vessel wall homeostasis may account for the rapidly progressive atherosclerosis associated with diabetes. Driven by hyperglycemia and oxidant stress, AGEs form to a greatly accelerated degree in diabetes. Within the vessel wall, collagen-linked AGEs may "trap" plasma proteins, quench nitric oxide activity and interact with specific receptors to modulate a large number of cellular properties. On plasma low density lipoproteins (LDL), AGEs initiate oxidative reactions that promote the formation of oxidized LDL. The interaction of AGEs with endothelial, as well as with other cells accumulating within the atherosclerotic plaque, such as mononuclear phagocytes and smooth muscle cells, provides a mechanism to augment vascular dysfunction. Specifically, the interaction of AGEs with vessel wall component increases vascular permeability, the expression of procoagulant activity and the generation of reactive oxygen species, resulting in increased endothelial expression of endothelial leukocyte adhesion molecules. AGEs potently modulate initiating steps in atherogenesis involving blood-vessel wall interactions, triggering an inflammatory-proliferative process and, furthermore, critically contribute to propagation of inflammation and vascular perturbation in established disease. Thus, a better understanding of the biochemical mechanisms by which AGEs contribute to such processes in the vessel wall could be relevant to devise preventive and therapeutic strategies for diabetic atherosclerosis.
晚期糖基化终末产物(AGEs)的形成是伴随糖尿病以及可能伴随一般炎症的一种重要生化异常。在此,我们总结并讨论近期的研究,这些研究表明AGEs对血管壁稳态的影响可能是糖尿病相关快速进展性动脉粥样硬化的原因。在高血糖和氧化应激的驱动下,糖尿病患者体内AGEs的形成程度大幅加速。在血管壁内,与胶原蛋白相连的AGEs可能“捕获”血浆蛋白,淬灭一氧化氮活性,并与特定受体相互作用以调节大量细胞特性。在血浆低密度脂蛋白(LDL)上,AGEs引发氧化反应,促进氧化型LDL的形成。AGEs与内皮细胞以及动脉粥样硬化斑块内积聚的其他细胞(如单核吞噬细胞和平滑肌细胞)之间的相互作用,提供了一种加剧血管功能障碍的机制。具体而言,AGEs与血管壁成分的相互作用会增加血管通透性、促凝活性的表达以及活性氧的产生,导致内皮白细胞黏附分子在内皮细胞上的表达增加。AGEs有力地调节动脉粥样硬化发生过程中涉及血管壁相互作用的起始步骤,引发炎症增殖过程,并且对已确诊疾病中的炎症传播和血管紊乱也起着关键作用。因此,更好地理解AGEs在血管壁中促成此类过程的生化机制,可能有助于制定糖尿病性动脉粥样硬化的预防和治疗策略。