The role of advanced glycation end products in retinal microvascular leukostasis
The role of advanced glycation end products in retinal microvascular leukostasis
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DOI：
10.1167/iovs.02-1063
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发表时间：
2003-10-01
影响因子：
4.4
通讯作者：
Pathog, APPACEIT
中科院分区：
文献类型：
--
作者：
Moore, TCB;Moore, JE;Pathog, APPACEIT
目的.糖尿病视网膜病变发病机制中的一个关键事件是白细胞与视网膜毛细血管的不适当粘附。已知晚期糖基化终产物（AGES）在慢性炎症过程中发挥作用，作者推测这些加合物可能在促进视网膜微血管内促炎途径的致病性增加中发挥作用。视网膜微血管内皮细胞（RMEC）处理与糖基化修饰的白蛋白（AGE-Alb）或未修饰的白蛋白（Alb）。通过电迁移率变动测定（EMSA）测量NF κ B DNA结合并用ELISA定量。此外，AGES对白细胞粘附内皮细胞单层的影响进行了研究。进行了进一步的研究，试图通过将AGE处理的细胞与可溶性AGE受体（sIgE）共孵育来证实这是AGE诱导的粘附。非糖尿病小鼠的平行体内研究评估了腹腔内给予AGE-Alb对ICAM-1 mRNA表达、NF κ B DNA结合活性、白细胞停滞和血视网膜屏障破坏的影响。用AGE-Alb处理显著增强视网膜内皮细胞（RMEC）中NF κ B的DNA结合活性（P = 0.0045），并增加白细胞与RMEC单层的粘附（P = 0.04）。而与sodium共同孵育后，后者则显著降低（P < 0.01）。与对照动物相比，输注AGE-Alb的小鼠早在48小时就表现出ICAM-1 mRNA的1.8倍增加（P < 0.001，n = 20），并且这种反应持续治疗7天。视网膜NF κ B的定量显示与对照水平相比，AGE-Alb输注增加三倍（AGE Alb对Alb，0.23对0.076，P < 0.001，n = 10只小鼠）。AGE-Alb处理小鼠还引起视网膜中白细胞淤滞的显著增加（AGE-Alb vs. Alb，6.89 vs. 2.53，n = 12，P < 0.05）和血视网膜屏障破坏的统计学显著增加（AGE-Alb vs. Alb，8.2 vs. 1.6 n = 10，P < 0.001）。AGES引起视网膜微血管内皮细胞NFκB上调，并且还观察到体外白细胞粘附的AGE特异性增加。此外，体内白细胞粘附增加被证明伴随着血视网膜屏障功能障碍。这些发现进一步证明AGES可能在糖尿病视网膜病变的发病机制中发挥重要作用。
PURPOSE. A critical event in the pathogenesis of diabetic retinopathy is the inappropriate adherence of leukocytes to the retinal capillaries. Advanced glycation end-products (AGES) are known to play a role in chronic inflammatory processes, and the authors postulated that these adducts may play a role in promoting pathogenic increases in proinflammatory pathways within the retinal microvasculature.METHODS. Retinal microvascular endothelial cells (RMECs) were treated with glycoaldehyde-modified albumin (AGE-Alb) or unmodified albumin (Alb). NFkappaB DNA binding was measured by electromobility shift assay (EMSA) and quantified with an ELISA. In addition, the effect of AGES on leukocyte adhesion to endothelial cell monolayers was investigated. Further studies were performed in an attempt to confirm that this was AGE-induced adhesion by co-incubation of AGE-treated cells with soluble receptor for AGE (sRAGE). Parallel in vivo studies of nondiabetic mice assessed the effect of intraperitoneal delivery of AGE-Alb on ICAM-I mRNA expression, NFkappaB DNA-binding activity, leukostasis, and blood-retinal barrier breakdown.RESULTS. Treatment with AGE-Alb significantly enhanced the DNA-binding activity of NFkappaB (P = 0.0045) in retinal endothelial cells (RMECs) and increased the adhesion of leukocytes to RMEC monolayers (P = 0.04). The latter was significantly reduced by co-incubation with sRAGE (P < 0.01). Mice infused with AGE-Alb demonstrated a 1.8-fold increase in ICAM-1 mRNA when compared with control animals (P < 0.001, n = 20) as early as 48 hours, and this response remained for 7 days of treatment. Quantification of retinal NFkappaB demonstrated a threefold increase with AGE-Alb infusion in comparison to control levels (AGE Alb versus Alb, 0.23 vs. 0.076, P < 0.001, n = 10 mice). AGE-Alb treatment of mice also caused a significant increase in leukostasis in the retina (AGE-Alb versus Alb, 6.89 vs. 2.53, n = 12, P < 0.05) and a statistically significant increase in breakdown of the blood-retinal barrier (AGE Alb versus Alb, 8.2 vs. 1.6 n = 10, P < 0.001).CONCLUSIONS. AGES caused upregulation of NFκB in the retinal microvascular endothelium and an AGE-specific increase in leukocyte adhesion in vitro was also observed. In addition, increased leukocyte adherence in vivo was demonstrated that was accompanied by blood-retinal barrier dysfunction. These findings add further evidence to the thinking that AGES may play an important role in the pathogenesis of diabetic retinopathy.