Surrogate Markers for Early Stage Diabetic Retinopathy

描述(由申请人提供)： 这项应用的总体目标是找到糖尿病早期变化的标志，这些标志将预测后来疾病的严重程度，以便患者能够得到适当的监测和治疗。最方便的标记是那些用血液测量的标记。因此，我们建议寻找可能在血清中发现的早期替代标志物。视网膜血管细胞丢失是导致糖尿病视网膜病变的一个突出的早期特征，可能反映了全身发生的血管变化。因此，与微血管细胞死亡相关的可溶性蛋白可能成为实验性糖尿病视网膜病变的有用替代终点，以及导致终末期疾病的其他临床变化的早期标志物。在糖尿病动物模型中寻找基因表达的变化是不现实的，因为在这些模型中，视网膜的早期血管变化没有很好地描述，是可变的，并且是持续的。因此，我们需要一种具有快速而深刻的血管丢失、基因表达变化被放大的模型。在围产期小鼠中，高氧抑制视网膜血管的发育，并通过细胞凋亡在5天内导致80%以上的血管萎缩，这一过程可能与早期糖尿病视网膜病变平行。高氧条件下血管的快速和放大丢失为研究视网膜血管变性的潜在生化机制提供了一个很好的模型。采用基因芯片技术检测高氧处理小鼠与正常小鼠在4个时间点的基因表达差异。还将评估每组随时间的变化。将使用4种不同的方法对信息进行分析，以对分泌因子的基因进行排序。前20个候选基因将通过TaqMan实时RT-PCR进行验证，以评估每个对照基因(亲环素)表达的拷贝数。最佳候选者的可溶性蛋白质将在视网膜周细胞和内皮细胞中进行体外评估，以确定它们与细胞凋亡和血管丢失有关。使用这些方法，我们可能识别导致与糖尿病、视网膜和其他血管丢失相关的可溶性蛋白因子的基因变化。这些因素可以作为替代标记物，通过对患者血液的常规筛查，有效地及早发现糖尿病的变化，或者可能导致旨在阻止这些因素有害行为的新的治疗干预措施。

DESCRIPTION (provided by applicant): The overall goal of this application is to find markers of early changes in diabetes that will predict severity of later disease so that patients can be appropriately monitored and treated. The most convenient markers are those measured in blood. Therefore we propose to search for early surrogate markers that might be found in serum. Loss of retinal vascular cells is a salient early feature that leads to diabetic retinopathy, and probably reflects vascular changes that occur throughout the body. Thus soluble proteins associated with microvascular cell death may become a useful surrogate end-point in experimental diabetic retinopathy as well as early markers for other clinical changes that lead to end stage disease. It is not practical to search for changes in gene expression in diabetic animal models because in these models, the early vascular changes in the retina are not well characterized, are variable, and are prolonged. Therefore we need a model with rapid and profound loss of vessels, gene expression changes are amplified. In peritnatal mice, hyperoxia inhibits development of retinal blood vessels and causes greater than 80% vessel regression over 5 days through apoptosis, a process that is likely to parallel early stage diabetic retinopathy. The rapid and amplified vessel loss in hyperoxia provides a good model to study the underlying biochemical mechanisms involved in retinal vessel degeneration. Gene chip array technique will be used to assess difference in gene expression between hyperoxia treated and normal mice at 4 time points. Changes over time in each group will also be assessed. Information will be analyzed using 4 different approaches to sort the genes of secreted factors. The top 20 candidates will be verified by TaqMan real-time RT-PCR to assess copy number expressed per control gene (cyclophilin). The soluble proteins of the best candidates will be assessed in vitro in retinal pericyte and endothelial cells to be certain that they are associated with apoptosis and vessel loss. Using these approaches we are likely to identify gene changes leading to soluble protein factors associated with diabetic retinal and other vessel loss. These factors may be used as surrogate markers for effective early detection of diabetic changes through routine screening of patients' blood or may lead to new therapeutic interventions aimed at blocking the deleterious actions of those factors.