Nerve Growth Factor and Transient Receptor Potential (TRPV1) Channel in Diabetic

糖尿病患者的神经生长因子和瞬时受体电位 (TRPV1) 通道

• 批准号: 7457520
• 负责人: Vickram Ramkumar
• 金额: $ 21.68万
• 依托单位: SOUTHERN ILLINOIS UNIVERSITY SCH OF MED
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-04-01 至 2008-07-18
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7457520
• 关键词: 4-ethoxymethylene-2-phenyl-2-oxazoline-5-one; Amputation; Analgesics; Animals; Biochemical; C57BL/6 Mouse; Cell physiology; Characteristics; Chronic; Complication; Coupled; Cultured Cells; Data; Development; Diabetes Mellitus; Diabetic mouse; Disease; Enzyme-Linked Immunosorbent Assay; Esthesia; Goals; Healed; Hyperalgesia; Hypersensitivity; In Vitro; Injection of therapeutic agent; Insulin; Insulin-Dependent Diabetes Mellitus; Intervention; Lead; Measures; Mechanics; Mediating; Messenger RNA; Modeling; Molecular Biology Techniques; Mus; NADPH Oxidase; Nerve Fibers; Nerve Growth Factors; Neurons; Pain; Pathway interactions; Patients; Perception; Peripheral; Peripheral Nervous System Diseases; Pharmaceutical Preparations; Pharmacotherapy; Phenotype; Preparation; Production; Protein Overexpression; Proteins; Public Health; Reactive Oxygen Species; Role; Sampling; Sensory; Sensory Receptors; Skin; Skin Tissue; Spinal Ganglia; Stimulus; Superoxides; System; TRPV1 gene; Tactile; Testing; Thermal Hyperalgesias; Transducers; Transgenic Organisms; Ulcer; afferent nerve; base; diabetic; glycemic control; healing; human AKAP13 protein; human CYBA protein; in vivo; iodoresiniferatoxin; mouse model; neutrophil cytosol factor 67K; novel; protein expression; receptor; response; sensor; superoxide-generating NADPH oxidase; type I diabetic

DESCRIPTION (provided by applicant): Diabetic peripheral neuropathy (DPN) is a common chronic complication of type 1 diabetes, characterized by progressive loss of thermal, tactile and pain sensations. The loss of peripheral sensations, coupled with impaired microvascular function in DPN can contribute to non-healing ulcers and lead to amputations. The goal of this study is to determine the mechanism(s) involved in altered thermal sensation in DPN. One hypothesis states that DPN results from altered nerve growth factor (NGF) trophic support to dorsal root ganglion (DRG) neurons. We believe that NGF regulates a thermal sensor protein, transient receptor potential channel (TRPV1), presumably by activating the NADPH oxidase superoxide generating system. Accordingly, we propose that an increase in NGF early in diabetes mediates thermal hypersensitivity, while low NGF levels or damage to sensory nerves as the disease progresses leads to sensory loss. We will test this hypothesis based on the specific aims outlined. Aim 1. To determine whether NGF regulates thermal sensation, the expression of TRPV1 and NADPH oxidase subunits in vivo. This aim will test if in vivo administration of NGF promotes hyperalgesia and whether this increases TRPV1 and NADPH oxidase subunit expression. Mice will be administered NGF by intraplantar injections, followed by analgesic testing 24 h later. DRGs and hindpaw skin obtained from vehicle and NGF treated mice will be collected to determine TRPV1 and NADPH oxidase mRNA and protein expression. Aim 2. To determine if altered thermal sensitivity in diabetes is associated with changes NGF, TRPV1 and the expression and activity of NADPH oxidase subunits. Using a double transgenic mouse model of type 1 diabetes we will measure the levels of NGF in lysates of DRGs and skin preparations, followed by measuring TRPV1 and NADPH oxidase expression using biochemical and molecular biology techniques. Preliminary studies indicate increased levels of TRPV1 in DRG neurons and hind paw skin samples correlates positively with the hyperalgesic response. Aim 3. To determine whether NGF or insulin therapy restores normal thermal sensitivity and the normal expression of TRPV1 and NADPH oxidase subunits in diabetic mice. Based on the hypothesis that a deficiency in NGF produces the hypoalgesic phenotype characteristic of type 1 diabetic mice, we will administer NGF or insulin (to maintain adequate glycemic control) to these animals and determine if it restores normal thermal sensation. The thermal thresholds of euglycemic controls and diabetic animals will be determined prior to and following administering either vehicle, NGF and insulin or a combination of these agents. The data obtained from this study would provide a better understanding of the role of NGF and the TRPV1 receptor in the controlling thermal sensations thermal in DPN. PUBLIC HEALTH RELEVANCE: The proposed project will focus on understanding some of the changes in nerve cell function, which lead to loss of pain perception in patients with diabetes, a complication termed diabetic peripheral neuropathy. We believe that the information gained by this study could contribute significantly to our appreciation of this disease and contribute to the development of novel drug therapies.

描述（由申请人提供）：糖尿病周围神经病（DPN）是1型糖尿病的常见慢性并发症，其特征是热觉、触觉和痛觉进行性丧失。 DPN 中周围感觉的丧失以及微血管功能受损可能会导致溃疡难以愈合并导致截肢。本研究的目的是确定 DPN 中热感觉改变所涉及的机制。一种假设认为，DPN 是由于神经生长因子 (NGF) 对背根神经节 (DRG) 神经元的营养支持改变所致。我们认为，NGF 可能通过激活 NADPH 氧化酶超氧化物生成系统来调节热传感器蛋白瞬时受体电位通道 (TRPV1)。因此，我们认为糖尿病早期 NGF 的增加会介导热超敏反应，而随着疾病的进展，NGF 水平较低或感觉神经受损会导致感觉丧失。我们将根据概述的具体目标检验这一假设。目的 1. 确定 NGF 是否调节体内热感觉、TRPV1 和 NADPH 氧化酶亚基的表达。该目标将测试体内给予 NGF 是否会促进痛觉过敏，以及这是否会增加 TRPV1 和 NADPH 氧化酶亚基的表达。小鼠将通过足底注射施用 NGF，24 小时后进行镇痛测试。将收集从载体和 NGF 处理的小鼠获得的 DRG 和后爪皮肤，以确定 TRPV1 和 NADPH 氧化酶 mRNA 和蛋白质表达。目标 2. 确定糖尿病中热敏感性的改变是否与 NGF、TRPV1 以及 NADPH 氧化酶亚基的表达和活性的变化相关。使用 1 型糖尿病双转基因小鼠模型，我们将测量 DRG 和皮肤制剂裂解物中 NGF 的水平，然后使用生化和分子生物学技术测量 TRPV1 和 NADPH 氧化酶表达。初步研究表明，DRG 神经元和后爪皮肤样本中 TRPV1 水平升高与痛觉过敏反应呈正相关。目标 3. 确定 NGF 或胰岛素治疗能否恢复糖尿病小鼠的正常热敏感性以及 TRPV1 和 NADPH 氧化酶亚基的正常表达。基于 NGF 缺乏会产生 1 型糖尿病小鼠痛觉减退表型特征的假设，我们将给这些动物施用 NGF 或胰岛素（以维持足够的血糖控制），并确定其是否恢复正常的热感觉。将在施用媒介物、NGF和胰岛素或这些药剂的组合之前和之后确定血糖正常对照和糖尿病动物的热阈值。从这项研究中获得的数据将有助于更好地理解 NGF 和 TRPV1 受体在控制 DPN 热感觉中的作用。 公共健康相关性：拟议的项目将重点了解神经细胞功能的一些变化，这些变化会导致糖尿病患者失去疼痛知觉，这是一种称为糖尿病周围神经病变的并发症。我们相信，通过这项研究获得的信息可以极大地促进我们对这种疾病的认识，并有助于新型药物疗法的开发。