Role of calcium channels in the development of diabetic retinopathy

钙通道在糖尿病视网膜病变发展中的作用

基本信息

批准号：
8635018
负责人：
BRUCE A. BERKOWITZ
金额：
$ 19万
依托单位：
WAYNE STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-02-01 至 2016-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8635018
关键词：
Aging Appearance Area Biochemistry Blindness Blood Vessels Calcium Calcium Channel Calcium Channel Blockers Clinical Complications of Diabetes Mellitus Decision Making Development Diabetes Mellitus Diabetic Retinopathy Etiology Free Radicals Functional disorder Future Genetic Goals Histopathology Imaging Techniques Knockout Mice L-Type Calcium Channels Lead Lesion Link Magnetic Resonance Imaging Manganese Measurement Mediating Methodology Mission Mitochondria Modeling Molecular Target Morbidity - disease rate Mus Neurons Oxidants Oxidative Stress Pathogenesis Patients Phenotype Photoreceptors Prevention Public Health Reactive Oxygen Species Research Resolution Retina Retinal Retinal Diseases Role Signal Transduction Structure of retinal pigment epithelium Testing Therapeutic Thinking Trypsin Western Blotting Work analytical tool base biophysical properties brain tissue cell type diabetic diabetic patient effective therapy experience extracellular free radical oxygen improved in vivo in vivo imaging innovation novel preclinical study prevent public health relevance research study

Aging Appearance Area Biochemistry Blindness Blood Vessels Calcium Calcium Channel Calcium Channel Blockers Clinical Complications of Diabetes Mellitus Decision Making Development Diabetes Mellitus Diabetic Retinopathy Etiology Free Radicals Functional disorder Future Genetic Goals Histopathology Imaging Techniques Knockout Mice L-Type Calcium Channels Lead Lesion Link Magnetic Resonance Imaging Manganese Measurement Mediating Methodology Mission Mitochondria Modeling Molecular Target Morbidity - disease rate Mus Neurons Oxidants Oxidative Stress Pathogenesis Patients Phenotype Photoreceptors Prevention Public Health Reactive Oxygen Species Research Resolution Retina Retinal Retinal Diseases Role Signal Transduction Structure of retinal pigment epithelium Testing Therapeutic Thinking Trypsin Western Blotting Work analytical tool base biophysical properties brain tissue cell type diabetic diabetic patient effective therapy experience extracellular free radical oxygen improved in vivo in vivo imaging innovation novel preclinical study prevent public health relevance research study

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项目摘要

DESCRIPTION (provided by applicant): There remains an urgent need to prevent vision loss from diabetic retinopathy (DR), a common and significant problem in patients with diabetes. Preclinical studies have highlighted retinal oxidative stress in the pathogenesis of DR. We reason that identifying the retinal mechanisms mediating pathogenic oxidative stress in diabetes will be important in the development of new and effective treatments. In neurons, oxidative stress and L-type calcium channels (LTCCs) activity are closely linked: increased LTCC activity elevates intracellular calcium content which must then be removed against a steep inter/extracellular calcium concentration gradient via ATP-dependent mechanisms which generate oxygen free radicals. We have discovered that diabetes profoundly changes the overall activity of photoreceptor LTCCs. Remarkably, a non-anti-oxidant and photoreceptor-specific treatment that corrected the abnormal outer retinal LTCC phenotype in vivo concurrently eliminated diabetic retinal oxidative stress. These experiments, using a validated and analytical tool (MEMRI), provide the first evidence for an unexpected and potentially very important discovery linking abnormal photoreceptor LTCCs and oxidative stress in diabetes. In the retina there are 3 major LTCC subtypes (Cav): Cav1.2 (located in inner retina), Cav1.3 (in inner retina, photoreceptor, and retinal pigment epithelium layers), and Cav1.4 (only in photoreceptors. How diabetes alters photoreceptor subtype channels are not yet known. We hypothesized that diabetes induces reproducible abnormalities in photoreceptor Cav1.3 and 1.4 expression and activity, and these changes actively contribute to oxidative stress and diabetic retinopathy. To begin to evaluate our new working hypothesis, we propose the following specific aim, which will take full advantage of our expertise in blending high resolution and analytical in vivo imaging of photoreceptor pathophysiology (manganese-enhanced MRI) with biochemistry (reactive oxygen species, western blot analysis (channel expression)) and histopathology (trypsin digest) in models of DR. SA 1: Test that diabetic alterations in photoreceptor Cav1.3, and 1.4 LTCC activity are required for oxidative stress and DR. The proposed experiments will open up a new line of scientific inquiry that is expected to improve our understanding about the origins of oxidative stress in DR. Because Cav1.3 and 1.4 subtypes are relatively insensitive to commonly used calcium channel blockers, our specific genetic and pharmacological approaches in concert with a novel imaging technique make these studies highly significant. These experiments will be crucial in the identification of new molecular targets for prevention and treatment of DR. The proposed research is highly innovative because it investigates a previously unsuspected but key role of photoreceptor LTCC subtype abnormalities in diabetes-induced oxidative stress, and will thus establish a firm scientific basis for changing current thinking regarding the origins of, and therapeutic options for, pathogenic oxidative stress in DR.

描述（由申请人提供）：迫切需要防止糖尿病性视网膜病（DR）的视力丧失，这是糖尿病患者的常见和重大问题。临床前研究突出了DR的发病机理中的视网膜氧化应激。我们认为，确定介导糖尿病致病氧化应激的视网膜机制对于新的有效治疗的发展至关重要。在神经元中，氧化应激和L型钙通道（LTCC）的活性紧密相连：LTCC活性的增加会提高细胞内钙含量，然后必须通过ATP依赖性机械性的陡峭的细胞间/外钙浓度梯度去除，这些机制产生了产生氧气的自由基。我们发现糖尿病深刻地改变了感光体LTCC的整体活性。值得注意的是，一种非抗氧化剂和感光特异性治疗，在体内纠正了异常的视网膜外LTCC表型，同时消除了糖尿病性视网膜氧化应激。这些实验使用经过验证和分析工具（MEMRI）提供了第一个证据，证明了将异常光感受器LTCC和糖尿病中氧化应激联系起来的意外且潜在非常重要的发现。在视网膜中，有3个主要的LTCC亚型（CAV）：CAV1.2（位于视网膜内部），CAV1.3（在视网膜内部，光感受器和视网膜色素上皮层中）和CAV1.4（仅在光感受器中。仅在光感受器中。光感受器CAV1.3和1.4表达和活性的异常，这些变化积极地有助于氧化应激和糖尿病性视网膜病，以开始评估我们的新工作假设，我们提出了以下特定目标，这将充分利用我们在混合高分辨率和分析的photioly pathery pathery pathery photiolysoligy（MR）中的优势。（反应性氧，蛋白质印迹分析（通道表达）和组织病理学（胰蛋白酶消化）SA 1：测试光感受器CAV1.3的糖尿病改变，氧化应激需要1.4 LTCC活性。由于CAV1.3和1.4亚型对常用的钙通道阻滞剂相对不敏感，因此我们的特定遗传和药理学方法与新型成像技术一致，使这些研究变得非常重要。这些实验对于鉴定用于预防和治疗DR的新分子靶标至关重要。拟议的研究具有高度创新性，因为它研究了糖尿病诱导的氧化应激的光感受器LTCC LTCC亚型异常的前所未有但关键的作用，因此将建立一个牢固的科学基础，以改变有关DR中的，致病性氧化应激的目前有关的目前的思维，以及针对DR的致病性氧化应激的疗法。