Islet on a Chip

 描述：糖尿病是由于胰岛衰竭导致发病率和死亡率增加所致。这种疾病的机制研究受到低可获得性、高变异性和人类胰岛成本的阻碍。我们的最新进展导致了第一个成功的方法，从人类胚胎干细胞(ES)体外产生成熟的、对葡萄糖敏感的分泌胰岛素的b细胞。这种方法及其使用人类诱导性多能干细胞的应用，提供了几乎无限的标准化人类β细胞。此外，由于β细胞可以从患者的iPS细胞中制备出来，因此可以分析正常和疾病状态。这一进展为胰岛素依赖型糖尿病患者的细胞替代疗法提供了可再生的b细胞来源，并提供了执行严格的疾病建模以确定所有糖尿病患者的治疗靶点的机会。 尽管取得了这些进展，但挑战依然存在。缺乏可靠、灵敏和常规的技术来评估β细胞的功能。此外，b细胞本身不太可能概括涉及胰岛功能的复杂生物学。因此，这项拟议的研究旨在将干细胞和胰岛生物学的方法与组织工程相结合，以设计、建立和测试体外生成人类胰岛的新技术，并评估其在微流体设备中的功能。利用逆向工程原理，我们将设计和制造一种生物启发的微流控芯片，支持含有b细胞的细胞团的生存和功能。这 “胰岛芯片”设计将使对β单元功能的严格和灵敏的评估超越当前的技术。该芯片还将提供一个平台，通过量化人类身体胰岛的功能变异性来评估它们。同时，我们寻求使用自上而下和自下而上的组织工程方法相结合的方法在体外生成完整的胰岛。来自人类干细胞(ES和iPS)的内分泌祖细胞将被引入一种芯片，该芯片旨在筛选底物、基质和机械力的组合，以确定支持向所有内分泌细胞类型的胰岛样结构分化的利基。我们将在我们的胰岛芯片中对得到的干细胞去除的胰岛进行评估，以描述这些ES细胞胰岛、b细胞单独和身体胰岛之间的功能差异。最后，我们将使用这些技术进行疾病建模和药物筛选，从代表不同疾病状态(健康、1型、2型糖尿病，MODY)的iPS细胞中生成健康和患病的胰岛，并评估这些胰岛的功能和对糖尿病药物的反应。这些研究将提供经过验证的技术，这些技术将增加我们对糖尿病的了解，并加快新疗法的开发。

 DESCRIPTION: Mellitus results from failure pancreatic islets leading to an increase in morbidity and mortality. Mechanistic studies of this disease are hindered by low availability, high variabiliy and the cost of human islets. Our recent advances have led to the first successful method to generate mature, glucose sensing- insulin secreting b cells from human embryonic stem (ES) cells in vitro. This method, and its application using human iPS cells, provides a virtually unlimited supply of standardized human β cells. Moreover, as the β cells can be prepared from patient iPS cells, normal and diseased states can be analyzed. This advance provides a renewable source of b cells for cell replacement therapy for insulin dependent diabetics and the opportunity to perform rigorous disease modeling to identify therapeutic targets for all diabetics. Despite these advances, challenges remain. Robust, sensitive and routine technologies to assess β cell function are lacking. Further, it is unlikely that b cells by themselves will recapitulate the complex biology involved in islet function. As such, the proposed research aims to combine approaches in stem cell and islet biology with tissue engineering to design, build and test new technologies for generating human islets in vitro and assessing their function in microfluidic devices. Using reverse engineering principles we will design and build a bio-inspired microfluidic chip that supports the survival and function of cell clusters containing b cells. This "islet chip" design will enable rigorous and sensitive evaluation of β cell function that goes beyond current technologies. This chip will also provide a platform to evaluate human cadaveric islets by quantifying their functional variability. In parallel, we seek to generate whole islets i vitro using a combination of top-down and bottom-up tissue engineering approaches. Endocrine progenitors from human stem cells (ES and iPS) will be introduced to a chip designed to screen a combination of substrates, matrixes and mechanical forces to identify a niche that supports differentiation to islet-like structures with all endocrine cell types. The resulting stem cell-derved islets will be evaluated in our islet chip to describe the functional differences between these ES-islets, bcells alone and cadaveric islets. Finally, we will use these technologies for disease modeling and drug screening by generating healthy and diseased islets from iPS cells representing different disease states (healthy, type 1, type 2 diabetes, MODY) and evaluate the function and response of these islets to diabetes drugs. These studies will provide validated technologies that will increase our understanding of diabetes and speed development of new therapies.