Microfluidic devices for determining dynamics of islets of Langerhans

用于确定朗格汉斯岛动态的微流体装置

• 批准号: 8637055
• 负责人: Michael Gabriel Roper
• 金额: $ 33.02万
• 依托单位: FLORIDA STATE UNIVERSITY
• 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 2017-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8637055
• 关键词: Acetylglucosamine; Affect; Automation; Behavior; Biological Assay; Color; Communication; Complex; Cytolysis; Data; Dependence; Detection; Development; Devices; Feedback; Fluorescence Anisotropy; Fluorescent Dyes; Frequencies; Ganglia; Generations; Geometry; Glucagon; Glucose; Goals; Health; Healthcare; Histocompatibility Testing; Human; Incidence; Insulin; Islets of Langerhans; Knowledge; Laboratories; Link; Liver; Measurement; Measures; Membrane; Methods; Microfluidic Microchips; Microfluidics; Mission; Modeling; Modification; Non-Insulin-Dependent Diabetes Mellitus; Pancreas; Pathogenesis; Peptides; Peripheral; Physiologic pulse; Physiology; Post-Translational Protein Processing; Process; Production; Proteins; Public Health; Reactive Oxygen Species; Research; Role; System; Techniques; Technology; Testing; Tissues; Toxic effect; Work; analytical method; base; blood glucose regulation; design; diabetic; extracellular; glucose uptake; in vivo; innovation; insulin secretion; insulin signaling; islet; neurotransmitter release; novel; pandemic disease; polycarbonate; protective effect; public health relevance; technique development; therapeutic development

DESCRIPTION (provided by applicant): There is a gap in understanding how the numerous islets in the pancreas synchronize to produce oscillatory insulin secretion. Continued existence of this gap represents an important problem because these oscillations are essential for proper glucose uptake by the liver and peripheral tissues and type II diabetics have perturbed oscillations. The long-term goal of the Roper laboratory is to decipher islet communication by developing new analytical techniques. The objective of this proposal is to identify the mechanism of islet synchronization, and identify the effects it has on islet physiology. The central hypothesis is that a feedback loop between the pancreas and peripheral tissues result in oscillatory glucose levels that synchronize islets, and that these oscillatory glucose levels are essential to islet function by limiting the generation of reactive oxygen species (ROS) within islets. This hypothesis was formulated on the basis of preliminary data formulated in the applicants' laboratories. The rationale behind this proposal is that a better mechanistic understanding of islet synchronization and protection from ROS damage will guide the development of new treatments for type II diabetes. Guided by strong preliminary data, this hypothesis will be tested by pursuing three specific aims: 1) Determine the mechanism of islet synchronization; 2) Identify the effects of synchronized islet behavior on ROS production; 3) Determine the effect of oscillatory glucose levels on protein modification by O-linked N- acetylglucosamine (O-GlcNAc). Under the first aim, a closed-loop microfluidic system will be used where secretory levels of peptides from islets will be used in a model of glucose uptake to calculate the extracellular glucose concentration to be delivered to the islets. Under the second aim, the amplitude and frequency dependence of glucose waveforms on ROS generation will be measured using a microfluidic device that allows simultaneous testing of a range of waveform amplitudes while measuring intraislet ROS levels. Under the third aim, the amount of O-GlcNAc-modified proteins produced under oscillatory and static glucose levels will be compared using a chemoenzymatic detection method. The approach is innovative because it utilizes novel microfluidic systems for determining the mechanism of islet synchronization while also testing a new paradigm in islet physiology, namely the protective role of oscillatory dynamics in islet physiology. The proposed research is significant because type II diabetics have perturbed insulin oscillations, making it critical to understand the mechanism of islet synchronization and protection for proper glucose homeostasis. Ultimately, such knowledge has the potential to guide the development of therapeutics for reducing the problems associated with glucose toxicity in type II diabetics.

描述（由申请人提供）：了解胰腺中的众多胰岛同步以产生振荡性胰岛素分泌存在差距。持续存在该差距是一个重要的问题，因为这些振荡对于肝脏和周围组织的适当葡萄糖吸收至关重要，II型糖尿病患者具有干扰的振荡。 ROPER实验室的长期目标是通过开发新的分析技术来破译胰岛通信。该建议的目的是确定胰岛同步的机理，并确定其对胰岛生理学的影响。中心假设是，胰腺和周围组织之间的反馈回路会导致同步胰岛同步的振荡葡萄糖水平，并且这些振荡性葡萄糖水平对于胰岛在胰岛内的产生而产生了必不可少的胰岛功能至关重要。该假设是根据申请人实验室中提出的初步数据提出的。该提案背后的理由是，对胰岛同步和防止ROS损害的保护有了更好的理解，将指导II型糖尿病的新疗法的发展。在强有力的初步数据的指导下，将通过追求三个特定目的来检验该假设：1）确定胰岛同步的机理； 2）确定同步胰岛行为对ROS产生的影响； 3）确定振荡性葡萄糖水平对通过O连接的N-乙酰葡萄糖（O-GLCNAC）的蛋白质修饰的影响。在第一个目标下，将使用闭环微流体系统，如果将胰岛的分泌肽水平用于葡萄糖摄取模型中，以计算细胞外葡萄糖浓度以递送到胰岛。在第二个目标下，将使用微流体设备测量葡萄糖波形对ROS生成的幅度和频率依赖性，该设备允许同时测试一系列波形振幅，同时测量Intrieslet ROS水平。在第三个目标下，将使用化学酶检测方法比较在振荡和静态葡萄糖水平下产生的O-GLCNAC修饰蛋白的量。该方法具有创新性，因为它利用新型的微流体系统来确定胰岛同步的机理，同时还测试了胰岛生理学中的新范式，即振荡动力学在胰岛生理学中的保护作用。拟议的研究很重要，因为II型糖尿病患者具有干扰胰岛素振荡，因此了解胰岛同步的机理和对适当葡萄糖稳态的保护机制至关重要。最终，这种知识有可能指导疗法的发展，以减少II型糖尿病患者中与葡萄糖毒性相关的问题。