Blocking vascular permeability by targeting CD148; a novel approach for treating retinopathy

背景资料：糖尿病性视网膜病变是由高血糖引起的糖尿病并发症，高血糖会导致眼睛后部的血管渗透，导致血液和液体渗漏。随着病情的进展，发生血管生成，导致更多有缺陷的血管的形成，从而加剧病情。糖尿病性视网膜病变影响高达80%的所有糖尿病患者，他们患有糖尿病20年或更长时间。虽然血糖水平的良好管理可以显着减轻这种情况的严重程度，当治疗是必要的手术和药物治疗的使用。对于这种情况，通常规定每月通过玻璃体内注射施用抗VEGF药物。然而，对于这种方法的使用和功效存在几个问题，尤其是患者对这种疗法的高水平无应答（>45%）以及生产和施用这些药物的费用。因此，有必要确定新的治疗目标，目的是改善或提供一种替代现有的treatment.Research问题：我们已经确定了一种新的途径，当刺激阻断血管通透性反应，这种反应，如VEGFA和缓激肽的已知诱导剂。该途径通过刺激内皮细胞表面的蛋白酪氨酸磷酸酶受体（CD148）发挥作用。我们已经鉴定了与CD 148相互作用并阻断血管通透性的肽QM 107，然而，我们的初步数据表明，衍生自CD 148胞外结构域的重组蛋白在抑制血管通透性和血管生成反应方面具有更有效的作用。本项目的目的是进一步探索这一点，并回答以下问题：1）实现血管通透性抑制所需的CD 148衍生的最小肽序列是什么？2)这比QM107更有效吗？3)CD148衍生肽也能阻断血管生成吗？4)这种肽在糖尿病视网膜病变的体内模型中起作用吗？技术：该项目将包括怀特福德实验室经常使用的广泛技术。将使用分子生物学和蛋白质纯化方法，以及一些生物信息学。将在体内使用渗透性测定，如Myles测定，以及用于在鼠眼中可视化血管渗漏的新方法。此外，还将采用基于细胞的血管生成和血管渗透性测定。

Background: Diabetic retinopathy is a complication of diabetes caused by high blood sugar which causes permeabilisation of blood vessels at the back of the eye resulting in the leakage of blood and fluids. As the condition progresses angiogenesis occurs leading to the formation of more defective blood vessels exacerbating the condition. Diabetic retinopathy affects up to 80% of all diabetes patients who have had the disease for 20 years or more. Although good management of blood sugar levels can significantly alleviate the severity of this condition, when treatment is necessary both surgical and drug based therapies are used. The administration of anti-VEGF drugs via intra-vitreal injection on a monthly basis is commonly prescribed for this condition. However, there are several concerns with the use and efficacy of this approach, not least the high level of patient non-response to this therapy (>45%) and the expense of producing and administering these drugs. There is therefore a need to identify novel therapeutic targets with the aim of improving or offering an alternative to existing treatments.Research Question: We have identified a novel pathway which when stimulated blocks vascular permeability responses to known inducers of this response such as VEGFA and bradykinin. The pathway acts through the stimulation of a protein tyrosine phosphatase receptor (CD148) on the surface of endothelial cells. We have already identified a peptide QM107 which interacts with CD148 and blocks vascular permeability, however our preliminary data would suggest that recombinant proteins derived from the extracellular domain of CD148 have an even more efficacious effect in inhibiting vascular permeability and angiogenic responses. The purpose of this project is to explore this further and in so doing answer the following questions:1) What is the minimum peptide sequence derived from CD148 required to achieve inhibition of vascular permeability?2) Is this more effective than QM107?3) Can the CD148 derived peptide also block angiogenesis?4) Does this peptide work in an in vivo model of diabetic retinopathy?Techniques: This project will encompass a broad range of techniques which are routinely used in the Whiteford lab. Molecular Biology and protein purification approaches will be used, with some bioinformatics. Permeability assays such as the Myles assay will be used in vivo, as will a novel approach for visualisation vessel leakage in murine eyes. In addition cell based assays for angiogenesis and vascular permeability will also be employed.