CAREER: Probing Mechanisms of Beta Cell Dysfunction via Quantitative Droplet Molecular Transport

在糖尿病患者中，胰腺中的特殊细胞(称为β细胞)的胰岛素分泌受损，这种损害可能与β细胞周围局部环境中的化学因素有关。特别重要的是糖尿病的两个常见危险因素：高脂肪饮食(脂肪酸)和缺乏足够的氧气。在这个项目中，一种新型的微型泵将精确地控制β细胞的局部环境，从而可以定量和精确地研究糖尿病的发病机制。研究结果将改变人们对糖尿病如何发展的理解，并可能解释为什么尽管有相似的危险因素，但并非所有肥胖患者都会患上糖尿病。这些新颖和变革性的生物医学科学和工程调查(或实验)将由一个跨学科、同行学习的学生团队在首席调查员的指导下进行。研究也与教育交织在一起，来自研究生、本科生、当地高中和小学的学生都参与了该项目的实验、解释和同行教学方面。该提案侧重于通过在一个名为“定量液滴分子传输(QDMT)”的高度集成平台上进行的研究，探索糖尿病的标志--β细胞功能障碍的机制。该平台基于PI的“智能微凝胶”液滴和一种新型的微流体特斯拉泵。初步研究的两个机制是：1)新抗原与游离脂肪酸(FFA)暴露的β细胞结合而增强免疫原性；2)FFA与缺氧在调节脂肪细胞细胞因子方面的潜在协同作用导致β细胞损伤。QDMT是一种独特的原位蛋白质传输定量工具，其原因在于三个新特性：1)智能微凝胶允许在原位修饰抗原的同时检测抗体结合，即在多孔微滴内，珠状生物传感器可以放置在目标细胞旁边，从而大大缩短了扩散长度，从而加快了敏感蛋白质的原位检测；2)微型无叶片特斯拉泵优化了边界层的使用，实现了传统泵难以实现的完全密封的连续流动；3)可以改变微通道尺寸，以创建可预测的扩散模型来对分子动力学进行量化。研究计划围绕三个目标组织：1)利用细胞和生物传感器负载的智能微凝胶、微型特斯拉泵和可重新配置的微流体来设计qDMT。2)应用qDMT研究新抗原(胰岛素、GAD、IA-2、ZnT8)在FFA暴露的β细胞中的结合；3)应用qDMT研究FFA+低氧协同作用于脂肪细胞细胞因子(IL6、TNFα)调节β功能障碍。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，认为值得支持。

In diabetes, insulin secretion is impaired in specialized cells (called beta cells) in the pancreas, and this impairment may be related to chemical factors in the local environment around the beta cells. Of particular importance are two common risk factors of diabetes: a fatty diet (fatty acids) and lack of sufficient oxygen. In this project, a novel miniaturized pump will precisely control the beta cells' local environment so that the mechanisms of diabetes can be studied quantitatively and precisely. Results of the research will transform understanding of how diabetes develops and may explain why not all obese patients develop diabetes despite similar risk factors. These novel and transformative biomedical science and engineering investigations (or experiments) will be conducted by a team of interdisciplinary, peer-learning students, under the guidance of the principle investigator. Research is also interwoven with education, where students from graduate, undergraduate, local high school, and elementary school all participate in the experimental, interpretive, and peer-teaching aspects of the project.The proposal focuses on probing mechanisms of beta cell dysfunction, a hallmark of diabetes, through studies performed in a highly integrated platform termed "quantitative droplet molecular transport (qDMT)" based on the PI's "smart microgel" droplets and a novel microfluidic Tesla pump. The two mechanisms for initial study are 1) enhanced immunogenicity as a result of neoantigen binding to free fatty acid (FFA) exposed beta cells and 2) beta cell impairment as a result of a potential synergy between FFA and hypoxia in modulating adipocyte cytokines. The qDMT is a unique tool for quantifying protein transport in situ due to three novel features:: 1) Smart microgels allow antibody binding to be assayed while modifying the antigens in situ, i.e., within the porous droplets, bead biosensors can be placed right next to cells of interest so the diffusion length is dramatically shortened, accelerating sensitive protein detection in situ; 2) The miniaturizing bladeless Tesla pump optimizes use of boundary layers, enabling a completely sealed, continuous flow difficult to achieve with conventional pumps and 3) Microchannel dimensions can be varied to create predictable diffusion models to quantify molecular kinetics. The Research Plan is organized around three objectives: 1) Engineer qDMT with cell & biosensor laden smart microgels, a micro-Tesla pump and reconfigurable microfluidics. 2) Apply qDMT to study neoantigen (insulin, GAD, IA-2, ZnT8) binding in FFA exposed beta cells and 3) Apply qDMT to study FFA+hypoxia synergy in adipocyte cytokine (IL6, TNFá) modulation of beta dysfunction.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.