Microfluidic Devices for Determining Dynamics of Islets of Langerhans

胰岛分泌胰岛素和胰高血糖素的动态变化及其作用 这些动力学在肝葡萄糖调节中的作用是未知的。罗珀的长期目标 该实验室的目标是解码细胞通讯，以了解正常的生物功能， 疾病进展。本建议的目的是确定调节动态的控制机制， 胰岛的激素释放以及肝脏的动态激素输入如何优化净肝葡萄糖控制 由肝。中心假设是胰岛释放的胰岛素和胰高血糖素与胰岛素相互作用。 肝脏产生一个反馈回路，该反馈回路控制胰岛行为，设置胰岛素的相位， 胰高血糖素振荡，并促进最佳的肝脏代谢。执行这项工作的理由是 彻底了解葡萄糖调节激素分泌和葡萄糖处理的动力学， 肝脏可能会导致治疗方法的设计，减轻并发症相关的 糖尿病和其他代谢疾病。在强有力的初步数据的指导下，这一假设将得到检验， 追求三个具体目标：1）确定胰岛释放葡萄糖调节激素的动力学，2） 确定来自胰岛的小分子分泌的动力学，所述小分子分泌形成激素反应，以及3）确定 肝细胞对动态激素谱的代谢反应。在第一个目标下， 将利用高时间分辨率测量来自单个胰岛的胰高血糖素分泌。该方法将 与我们的胰岛素释放测定结合，以使激素振荡幅度、频率和 阶段关系有待确定。在第二个目标中，γ-氨基丁酸和谷氨酸的分泌将被抑制。 与胰岛素和胰高血糖素分泌同时从胰岛监测。这将有助于确定 这些小分子在振荡激素释放中所起的作用。在第三个目标中，脉动激素 在监测葡萄糖输出的同时，将分布图传递给肝细胞。这种方法将有助于 了解动态激素谱如何控制肝脏行为。该研究具有创新性 因为在该提议中开发的微流体系统和测量方法将允许 首次观察到胰岛和肝细胞的动态行为。这些结果将提供一个 胰腺和肝脏之间相互作用的知识显着增加，这对充分利用肝脏至关重要。 了解葡萄糖稳态的机制以及它在代谢疾病中是如何出错的。最后， 这些知识有可能指导治疗的发展，以减少与 II型糖尿病患者的血糖水平不受控制。

The secretory dynamics of insulin and glucagon from individual pancreatic islets of Langerhans and the roles that these dynamics play in hepatic glucose regulation are unknown. The long-term goal of the Roper laboratory is to decode cellular communication to enable understanding of normal biological function and disease progression. The objective of this proposal is to identify the control mechanisms that regulate dynamic hormone release from islets and how dynamic hormone input to the liver optimizes net hepatic glucose control by the liver. The central hypothesis is that insulin and glucagon released from islets of Langerhans interact with the liver to generate a feedback loop that synchronizes islet behavior, sets the phase of the insulin and glucagon oscillations, and promotes optimal hepatic metabolism. The rationale for performing this work is that a thorough understanding of the dynamics of glucose-regulatory hormone secretion and glucose handling by the liver may lead to the design of therapeutic approaches that alleviate the complications associated with diabetes and other metabolic diseases. Guided by strong preliminary data, this hypothesis will be tested by pursuing three specific aims: 1) Determine the dynamics of glucose-regulatory hormone release from islets, 2) Identify the dynamics of small molecule secretion from islets that shape hormonal response, and 3) Identify the metabolic response of hepatocytes to dynamic hormonal profiles. Under the first aim, a novel approach to measure glucagon secretion from single islets with high temporal resolution will be utilized. This method will be incorporated with our assay for insulin release to enable hormone oscillation amplitudes, frequencies, and phase relationships to be identified. In the second aim, γ-aminobutyric acid and glutamate secretion will be monitored from islets simultaneously with insulin and glucagon secretion. This will enable the determination of the roles that these small molecules play in oscillatory hormone release. In the third aim, pulsatile hormone profiles will be delivered to hepatocytes while monitoring glucose output. This method will facilitate the understanding of how dynamic hormone profiles control hepatic behavior. The proposed research is innovative because the microfluidic systems and measurement approaches developed in this proposal will allow dynamics of islet and hepatocyte behavior to be observed for the first time. These results will provide a significant increase in the knowledge of the interplay between the pancreas and liver, which is crucial for fully understanding the mechanism of glucose homeostasis and how it goes awry in metabolic diseases. Ultimately, this knowledge has the potential to guide therapeutic development for reducing the problems associated with unregulated glucose levels in type II diabetics.