Beneficial effects of fenofibric acid on overexpression of extracellular matrix components, COX-2, and impairment of endothelial permeability associated with diabetic retinopathy.
Beneficial effects of fenofibric acid on overexpression of extracellular matrix components, COX-2, and impairment of endothelial permeability associated with diabetic retinopathy.
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DOI：
10.1016/j.exer.2015.08.010
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发表时间：
2015-11
影响因子：
3.4
通讯作者：
Roy S
中科院分区：
文献类型：
--
作者：
Roy S;Kim D;Hernández C;Simó R;Roy S
在非诺贝酸（FA）干预和降低糖尿病事件（FIELD）研究中，FA（一种降脂药物）已被证明可显著减轻糖尿病患者的黄斑水肿。在本研究中，我们研究了FA是否通过抑制环氧合酶-2（考克斯-2）（炎症的关键介质）和减少纤连蛋白（FN）和IV型胶原（科尔IV）（糖尿病视网膜病变中上调的两种基底膜（BM）组分）的过度表达来降低血管通透性。将大鼠视网膜内皮细胞（RREC）在含有或不含有FA的正常（N：5 mM葡萄糖）或高（HG：30 mM葡萄糖）培养基中生长7天。使用蛋白质印迹分析评估从这些细胞分离的总蛋白质的FN、科尔IV、考克斯-2和紧密连接蛋白质闭锁小带-1（ZO-1）。此外，ZO-1的分布和定位通过免疫荧光显微镜测定，并通过体外渗透性（IVP）测定研究细胞单层通透性。HG培养的RREC中FN、科尔IV和考克斯-2的表达明显增加（分别为N的179%、144%和139%），ZO-1的表达明显降低（为N的48%）。在添加FA的HG培养基中生长的细胞显著降低FN、科尔IV和考克斯-2表达，分别降低47%、32%和34%，同时ZO-1表达增加42%。在平行研究中，IVP试验显示在HG培养基中生长的RREC的细胞单层渗透性显著增加（N的139%），FA处理显著降低。此外，免疫染色结果表明FA阻止HG诱导的ZO-1下调。研究结果表明，FA在降低过度通透性方面的有益作用至少部分是通过下调BM组分和炎症因子的异常过表达以及预防与糖尿病视网膜病变相关的紧密连接受损来介导的。
In the Fenofibric Acid (FA) Intervention and Event Lowering in Diabetes (FIELD) study, FA, a lipid-lowering drug, has been shown to significantly reduce macular edema in diabetic patients. In the present study, we investigated whether FA reduces vascular permeability by inhibiting cyclooxygenase-2 (COX-2), a critical mediator of inflammation, and reducing overexpression of fibronectin (FN) and collagen IV (Coll IV), two basement membrane (BM) components upregulated in diabetic retinopathy. Rat retinal endothelial cells (RRECs) were grown in normal (N:5 mM glucose) or high (HG:30 mM glucose) medium with or without FA for 7 days. Total protein isolated from these cells was assessed for FN, Coll IV, COX-2, and zonula occludens-1 (ZO-1), a tight junction protein, using Western blot analysis. In addition, the distribution and localization of ZO-1 was determined by immunofluorescence microscopy, and cell monolayer permeability was studied by in vitro permeability (IVP) assay. RRECs grown in HG medium showed significant increase in FN, Coll IV, and COX-2 expression (179%, 144%, 139% of N respectively), and a decrease in ZO-1 expression (48% of N) compared to those of N cells. Cells grown in HG medium supplemented with FA significantly reduced FN, Coll IV, and COX-2 expression by 47%, 32%, and 34% respectively, with concomitant increase in ZO-1 expression by 42%. In parallel studies, IVP assays showed a significant increase (139% of N) in cell monolayer permeability in RRECs grown in HG medium, which was significantly reduced with FA treatment. Additionally, immunostaining results indicated FA prevents HG-induced downregulation of ZO-1. The findings indicate that the beneficial effect of FA in reducing excess permeability is mediated, at least in part, by downregulating abnormal overexpression of BM components and inflammatory factors and preventing compromised tight junctions associated with diabetic retinopathy.