Role of the kallikrein-kinin system in diabetic retinopathy

激肽释放酶-激肽系统在糖尿病视网膜病变中的作用

• 批准号: 8323487
• 负责人: EDWARD P FEENER
• 金额: $ 37.94万
• 依托单位: JOSLIN DIABETES CENTER
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8323487
• 关键词: Acute; Adult; Age; Angioneurotic Edema; Area; Astrocytes; Biochemical Markers; Blindness; Blood Vessels; Bradykinin; Bradykinin B2 Receptor; Bradykinin Receptor; Carbonic Anhydrase I; Characteristics; Clinical; Collaborations; Complement 1 Inactivators; Data; Development; Dextrans; Diabetes Mellitus; Diabetic Retinopathy; Diabetic mouse; Diffuse; Edema; Endothelial Cells; Extravasation; Factor XII; Grant; Health; Hemorrhage; High-Molecular-Weight Kininogen; Hormones; Human; Image; In Vitro; Individual; Inflammation; Injection of therapeutic agent; Institutes; Kallikrein-Kinin System; Kininogenase; Kinins; Label; Lesion; Leukostasis; Mass Spectrum Analysis; Massachusetts; Measures; Mediating; Medicine; Mus; Nature; Optical Coherence Tomography; Pathogenesis; Pathway interactions; Permeability; Plasma Kallikrein; Prekallikrein; Proteolysis; Proteome; Proteomics; Publishing; Rattus; Receptor Activation; Reporting; Retina; Retinal; Retinal Edemas; Rodent; Rodent Model; Role; Streptozocin; Stroke; System; Technology; Tight Junctions; Time; Vascular Permeabilities; Work; base; carbonate dehydratase; dextran; diabetic; diabetic rat; extracellular; in vivo; intravitreal injection; macular edema; monolayer; neutralizing antibody; non-diabetic; novel; novel therapeutics; proliferative diabetic retinopathy; receptor; response; therapeutic target; vascular inflammation

DESCRIPTION (provided by applicant): Excessive retinal vascular permeability contributes to the pathogenesis of diabetic macular edema (DME), a leading cause of vision loss in working-age adults. We recently reported that activation of the kallikrein-kinin system (KKS) by intravitreal injection of carbonic anhydrase 1 (CA-I) in rats resulted in a rapid increase in retinal vascular permeability (RVP) followed by the development of focal areas of increased vascular leakage to fluorecein-labeled 2x106 Dal dextran conjugate at 48 hrs post injection (Gao et al. Nature Medicine 2007, Appendix 1). In addition, we showed that in the presence of diabetes, CA-I caused intraretinal thickening, measured by 3D optical coherence tomography (OCT), at this time point. To our knowledge, this is the first report of retinal thickening in a diabetic rodent that is similar to clinically evident retinal edema. We reported that CA-I-induced retinal edema was decreased by complement 1 inhibitor, neutralizing antibody to prekallikrein, and bradykinin receptor antagonism. We demonstrated that plasma kallikrein, factor XII, and high molecular weight kininogen, are present in their activated forms in vitreous from people with diabetic retinopathy. In preliminary studies, we have shown that intravitreal injection with activated purified plasma kallikrein, kallikrein(act), induced both acute diffuse RVP at 30 min and focal areas of RVP and retinal leukostasis at 48 h post injection. In addition, we show that the effects of kallikrein(act) on the development of focal areas of leakage to fluorecein-labeled 2x106 Dal dextran are increased in both rats and mice with diabetes compared with nondiabetic controls. Using cultured retinal microvessel endothelial cells and astrocytes, we have identified both bradykinin-dependent and -independent mechanisms of kallikrein action. Although the KKS has been identified as a key pathway of vascular inflammation and vasogenic edema in stroke and angioedema, little is known regarding the actions of the KKS on the retina and its potential role in diabetic retinopathy. This grant will investigate these effects of the KKS on retinal vascular function and examine the contribution of this system to diabetic retinal edema. Our studies will examine the hypothesis that diabetes increases the actions of kallikrein on the retina and that increased kallikrein action leads to increased retinal vascular permeability and edema via a combination of B2-R activation and kallikrein's direct effect on extracellular proteolysis. We will investigate the contributions of both bradykinin receptor-dependent and -independent mechanisms of plasma kallikrein action on the retina using both in vivo studies on diabetic and nondiabetic rodents and in vitro studies using retinal microvessel endothelial cells and astrocytes. In collaboration with Dr. James Fujimoto (Massachusetts Institute of Technology), we will characterize the effects of the KKS and diabetes on retinal ultrastructure using OCT. This grant will provide critical new information on plasma kallikrein actions in the retina that contribute to both the diffuse and focal lesions of RVP, inflammation, and retinal thickening, which have been implicated as primary causal factors and characteristics of DME. PUBLIC HEALTH RELEVANCE: This grant will characterize the role of plasma kallikrein-induced inflammation in diabetic retinopathy. This grant is based on exciting new data that has identified a hormone system that triggers retinal edema in diabetic rodent models. These studies could reveal new therapeutic strategies to treat diabetic macular edema, a leading cause of vision loss.

描述（由申请人提供）：过度的视网膜血管通透性有助于糖尿病性黄斑水肿（DME）的发病机理，这是工人年龄成人视力丧失的主要原因。 We recently reported that activation of the kallikrein-kinin system (KKS) by intravitreal injection of carbonic anhydrase 1 (CA-I) in rats resulted in a rapid increase in retinal vascular permeability (RVP) followed by the development of focal areas of increased vascular leakage to fluorecein-labeled 2x106 Dal dextran conjugate at 48 hrs post injection (Gao et Al。自然医学2007年，附录1）。此外，我们表明，在存在糖尿病的情况下，CA-I在此时间点通过3D光学相干断层扫描（OCT）测量引起视网膜内增厚。据我们所知，这是在糖尿病啮齿动物中与临床上明显视网膜水肿相似的首次报道。我们报道说，通过补体1抑制剂减少了CA-I诱导的视网膜水肿，中和抗体 prekallikrein和Bradykinin受体拮抗作用。我们证明了血浆kallikrein，XII因子和高分子量激素基因生成的糖尿病性视网膜病患者以玻璃体激活形式存在。在初步研究中，我们已经表明，玻璃体玻璃体注射用活化的纯化血浆kallikrein，kallikrein（ACT）诱导在30分钟时诱导急性弥漫性RVP，并在受伤后48小时在RVP和视网膜白细胞的焦点区域诱导。此外，我们还表明，与非糖尿病对照相比，大鼠和糖尿病的大鼠和小鼠，Kallikrein（ACT）（ACT）对氟菌标记的2x106 DAL右旋体的漏水区域的影响增加。使用培养的视网膜微血管内皮细胞和星形胶质细胞，我们已经确定了kallikrein作用的缓激肽依赖性和非依赖性机制。尽管KKS被确定为中风和血管性水肿中血管炎症和血管性水肿的关键途径，但对于KKS对视网膜的作用及其在糖尿病性视网膜病中的潜在作用知之甚少。该赠款将研究KKS对视网膜血管功能的这些影响，并研究该系统对糖尿病性视网膜水肿的贡献。我们的研究将研究以下假设：糖尿病会增加卡利克林对视网膜的作用，并增加Kallikrein的作用，从而通过B2-R激活和Kallikrein直接对细胞外蛋白水解的直接影响，从而导致视网膜血管通透性和水肿增加。我们将使用视网膜微血管内皮细胞和星形细胞对糖尿病患者和非糖尿病啮齿动物的体内研究以及使用视网膜微血管内皮细胞和星形细胞进行体内研究，研究血压素受体依赖性受体依赖性和非依赖性机制对视网膜的贡献。我们将与詹姆斯·富吉莫托（James Fujimoto）博士（马萨诸塞州理工学院）合作，我们将使用OCT来表征KKS和糖尿病对视网膜超建立的影响。该赠款将提供有关视网膜中血浆Kallikrein作用的关键新信息，这些信息既有助于RVP，炎症和视网膜增厚的弥漫性和局灶性病变，这些病变已被视为DME的主要因果因素和特征。公共卫生相关性：该赠款将表征等离子Kallikrein引起的炎症在糖尿病性视网膜病中的作用。该赠款基于令人兴奋的新数据，该数据已经确定了一种激素系统，该激素系统触发了糖尿病啮齿动物模型中的视网膜水肿。这些研究可以揭示新的治疗策略来治疗糖尿病性黄斑水肿，这是视力丧失的主要原因。