Altered expression of genes related to blood-retina barrier disruption in streptozotocin-induced diabetes
Altered expression of genes related to blood-retina barrier disruption in streptozotocin-induced diabetes
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DOI：
10.1016/j.exer.2009.01.006
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发表时间：
2009-06-01
影响因子：
3.4
通讯作者：
Schlingemann, Reinier O.
中科院分区：
文献类型：
--
作者：
Klaassen, Ingeborg;Hughes, John M.;Schlingemann, Reinier O.
血-视网膜屏障（BRB）的破坏是临床前糖尿病视网膜病变（PCDR）的早期现象。两种血管通透性途径可能受到影响，涉及内皮细胞紧密连接的细胞旁途径，以及由内吞囊泡（小窝）介导的内皮跨细胞途径。这两种途径对PCDR血管通透性的相对贡献尚不清楚。我们使用实时定量RT-PCR比较了对照条件下和链脲佐菌素诱导的糖尿病6周和12周后，以及暴露于VEGF和牛视网膜周细胞（BRPC）的牛视网膜内皮细胞（BRECs）中与这些通路相关的基因在整个大鼠视网膜中的转录水平。为了确认内皮特异性，在大鼠视网膜中进行免疫组织化学染色，并比较BRECs和BRPCs之间的mRNA转录水平。大多数细胞旁转运相关基因的mRNA和蛋白质由视网膜内皮细胞特异性表达，而囊泡转运相关的mRNA和蛋白质存在于各种视网膜细胞类型，包括内皮细胞。选定的内皮细胞紧密连接基因的表达，特别是occludin和claudin-5的表达在糖尿病视网膜和BRECs暴露于VEGF后减少。诱导糖尿病后，11个囊泡转运相关基因中有6个表达上调。其中，只有质膜囊泡相关蛋白（PV-1）是专门表达在BRECs，而不是在BRPC。PV-1的转录在糖尿病视网膜中被显著诱导，VEGF在BRECs中被显著诱导。Caveolin-1免疫染色主要见于视网膜血管，其mRNA水平在BRECs中是高度丰富的和VEGF诱导的。而内皮紧密连接基因occludin和claudin-5表现出短暂的下调，我们观察到长期上调糖尿病视网膜和VEGF诱导的表达在BRECs的囊泡转运相关基因caveolin-1和PV-1。在这项研究中观察到的基因表达谱的改变表明，在PCDR中视网膜毛细血管通透性增加的细胞旁途径和跨细胞内皮转运机制的长期参与的瞬时诱导。(C)2009爱思唯尔有限公司保留所有权利。
Disruption of the blood-retina barrier (BRB) is an early phenomenon in preclinical diabetic retinopathy (PCDR). Two vascular permeability pathways may be affected, the paracellular pathway involving endothelial cell tight junctions, and the endothelial transcellular pathway mediated by endocytotic vesicles (caveolae). The relative contribution of both pathways to vascular permeability in PCDR is unknown. We compared transcription levels in entire rat retina of genes related to these pathways between control conditions and after 6 and 12 weeks of streptozotocin-induced diabetes, as well as in bovine retinal endothelial cells (BRECs) exposed to VEGF and bovine retinal pericytes (BRPCs), using real-time quantitative RT-PCR. To confirm endothelial-specificity, immunohistochemical staining was performed in rat retina, and mRNA transcript levels were compared between BRECs and BRPCs. mRNA and protein of most paracellular transport-related genes were specifically expressed by retinal endothelial cells, whereas vesicle transport-related mRNA and proteins were present in various retinal cell types, including endothelial cells. Expression of selected endothelial cell tight junction genes and particularly that of occludin and claudin-5 was reduced in the diabetic retina and in BRECs after exposure to VEGF. Expression of 6 out of 11 vesicular transport-related genes was upregulated after induction of diabetes. Of these, only plasmalemma vesicle-associated protein (PV-1) was exclusively expressed in BRECs and not in BRPCs. PV-1 transcription was markedly induced in diabetic retina and by VEGF in BRECs. Caveolin-1 immunostaining was primarily found in the retinal vasculature, and its mRNA levels in BRECs were highly abundant and VEGF-inducible. Whereas the endothelial tight junction genes occludin and claudin-5 showed a transient downregulation, we observed long-term upregulation in diabetic retina and VEGF-induced expression in BRECs of the vesicular transport-related genes caveolin-1 and PV-1. The altered gene expression profiles observed in this study suggest a transient induction of the paracellular pathway and prolonged involvement of transcellular endothelial transport mechanisms in the increased permeability of retinal capillaries in PCDR. (C) 2009 Elsevier Ltd. All rights reserved.