Mouse-on-a-chip systems to evaluate pancreas-adipose tissue dynamics in vitro

 描述（由申请人提供）：脂肪组织（脂肪）不仅仅是甘油三酯的储存部位，现在已经了解到脂肪组织是一种复杂的多细胞内分泌器官，具有深刻的全身效应，改变几乎所有其他器官系统的功能。尽管它的重要性，但是，有一个缺乏信息的动态性质的脂肪组织中的脂肪因子分泌和营养摄取，突出了几个未满足的需要在方法。很少有技术存在询问少量的脂肪组织，并且缺乏方法来探索器官的动态功能。具体来说，我们对葡萄糖、胰岛素和脂肪功能之间的动态关系的认识有限，这突出了对更好的体外技术来研究胰腺-脂肪组织串扰的迫切需要。正如我们在上一个资助期所展示的那样，我们建议我们的微流体系统是满足这些持续需求的理想选择。我们的研究团队开发了用于培养内分泌组织的微流体方法，即来自C57 BL/6 J小鼠的胰岛和脂肪组织，以及用于激素分泌的采样。这些系统允许以标准技术不可能的方式动态询问组织。这项研究的长期目标是开发内分泌系统的体外模型，用于营养，代谢和药物发现。在短期内，我们的目标是开发一种小鼠芯片微流控系统，允许动态和定量测量激素分泌和营养吸收从初级组织。微流体装置将与小体积方法同时开发，以测定胰岛和脂肪组织的分泌或营养摄取，3D打印将用于改进我们的新型装置接口和组织培养方法。该提案的目标1旨在开发一种自动化微流体输入/输出多路复用器（μMUX），用于对进出内分泌组织的激素和营养素进行可推广的动态控制。目标2将导致有针对性的小容量兼容的激素和脂肪组织中游离脂肪酸的摄取测定。目的3和4本质上是生物学的，使用µMUX系统确定具有不同血糖动力学的内分泌组织中激素分泌、脂肪酸摄取和脂解的动力学（目的3），并使用共培养µMUX系统确定组织之间动态反馈的作用（目的4）。本研究的基本原理是提供一种灵活可编程的胰腺-脂肪动力学体外微模型，以测试与肠道-胰腺信号动力学、胰岛素/脂解/脂肪酸摄取动力学以及低胰岛素和葡萄糖（空腹或生酮代谢）下脂解调节相关的几个重要生物学假设。拟议的工作是有意义的，因为它是第一个在体外 模拟胰腺脂肪生理学，我们期望这将导致更好的信息对人类的饮食干预。因此，该提案在技术和生物方法方面具有创新性。初步证据有力地支持这些建议的可行性，研究小组有一个成功的记录。

 DESCRIPTION (provided by applicant): Rather than a mere storage site for triglycerides, it is now understood that adipose tissue (fat) is a complex, multicellular endocrine organ that has profound systemic effects, altering the function of nearly all other organ systems. Despite its importance, however, there is a lack of information on the dynamic nature of adipokine secretion and nutrient uptake in adipose tissue, highlighting several unmet needs in methodology. Few techniques exist to interrogate small amounts of adipose tissue, and there is a shortage of methods to explore dynamic function of the organ. Specifically, we have a limited view of the dynamic relationship between glucose, insulin, and adipose function, highlighting an immediate need for better in vitro techniques to study pancreas-adipose tissue crosstalk. As demonstrated in our previous funding period, we propose that our microfluidic systems are ideal to meet these ongoing needs. Our research team developed microfluidic approaches for culture of endocrine tissue, namely pancreatic islets and adipose tissue from C57BL/6J mice, as well as for sampling of hormone secretion. These systems permit dynamic interrogation of the tissues in ways not possible with standard techniques. The long-term goal of this research is to develop in vitro models of the endocrine system for applications in nutrition, metabolism, and drug discovery. In the short term, our objective is to develop a mouse-on-a-chip microfluidic system that permits dynamic and quantitative measurements of both hormone secretion and nutrient uptake from primary tissue. Microfluidic devices will be developed concurrently with small-volume methodology to assay secretion or nutrient uptake from pancreatic islets and adipose tissue, and 3D printing will be used to improve our novel device interfacing and tissue culture methods. Aim 1 of the proposal seeks to develop an automated microfluidic input/output multiplexer (µMUX) for generalizable dynamic control over hormones and nutrients to/from endocrine tissue. Aim 2 will result in targeted small-volume compatible assays for hormones and free fatty acid uptake in adipose tissue. Aims 3 and 4 are biological in nature, using the µMUX system to determine the dynamics of hormone secretion, fatty acid uptake, and lipolysis in endocrine tissues with varied glycemic dynamics (Aim 3), and determining the role of dynamic feedback between the tissues using a co-culture µMUX system (Aim 4). The rationale for this research to provide a flexibly programmable, in vitro micro-model of pancreas-adipose dynamics to test several important biological hypotheses related to gut-pancreas signaling dynamics, insulin/lipolysis/fatty acid uptake dynamics, and regulation of lipolysis at low insulin and glucos (fasting or ketogenic metabolism). The proposed work is significant as a first-of-its-kind in vitro mimic of pancreas-adipose physiology, which we expect will lead to better information on human dietary interventions. The proposal is thus innovative in its technological and its biological approaches. Preliminary evidence strongly supports the feasibility of these proposals, and the research team has a proven track-record of success.