Engineered Heterochronic Parabiosis on 3D Microphysiological Systems

项目摘要 异时共生，其中年轻和年老的动物通过手术连接以共享循环， 存在假定的“抗衰老”因素的证据，但循环因素介导的机制 对肌肉干细胞及其微环境的再生特性还有待阐明。由于 体内共生的复杂性和血液传播因素的动态性质，这些因素的可靠鉴定 体液因素仍然是一个主要障碍。为了克服这一挑战，张博士和他的团队将利用 先进的微工程方法，以建立一个3D微流体共生电路，可以控制机械 和生理相关的3D微环境中的生化线索。在这份提案中，他的团队将进一步 通过整合细胞类型特异性蛋白质标记系统来完善和升级体外联体共生平台 （MetRSL 2774 G转基因），以精确鉴定肌肉分泌蛋白，也称为肌因子，负责 对肌肉干细胞的再生作用。此外，还将采用靶向遗传学方法， 描述了氧化应激诱导的前衰老肌因子对肌肉干细胞功能的负面影响。 最后，该团队还将在Parabiois-on-a-chip中设计一个运动诱导的肌因子报告系统。 使用与蛋白质标记构建体MetRSL 274 G共表达的光遗传致动器（视紫红质2）。 利用这一报告，拟议的研究将确定新的收缩诱导的肌因子与抗衰老的性质 以及通过血脑屏障（BBB）对肌脑串扰发挥作用的肌因子。的 该项目的成功结果将对老年科学产生深远而广泛的影响。这种微创 3D微生理学系统可用于测试衰老或建模特征的各种研究 与年龄有关的疾病的体外研究。更重要的是，经过验证，本研究中使用的实验方法 该提案可以翻译为模仿人类共生，这将具有重要的临床意义。

PROJECT SUMMARY Heterochronic parabiosis, in which young and aged animals are surgically attached to share circulation, provided evidence of putative ‘anti-geronic’ factors exist but the mechanisms by which circulating factors mediate rejuvenating properties on muscle stem cells and their microenvironment have yet to be elucidated. Due to the complexity of in vivo parabiosis and the dynamic nature of blood-borne factors, reliable identification of these humoral factors remains a major hurdle. To overcome this challenge, Dr. Jang and his team will leverage advanced microengineering approaches to build a 3D microfluidic parabiosis circuit that can control mechanical and biochemical cues in the physiologically relevant 3D microenvironment. In this proposal, his team will further refine and upgrade the in vitro parabiosis platform by integrating a cell-type-specific protein labeling system (MetRSL2774G transgene) to precisely identify muscle secretome, also known as myokines, responsible for rejuvenation effects on muscle stem cells. In addition, the targeted genetics approach will be employed to delineate oxidative stress-induced pro-geronic myokines that negatively impact muscle stem cell function. Finally, the team will also engineer an exercise-induced myokine reporter system within parabiosis-on-a-chip using an optogenetic actuator (Channelrhodopsin 2) co-expressed with protein labeling construct, MetRSL274G. Using this reporter, proposed studies will identify novel contraction-induced myokines with anti-geronic properties and myokines that pass the blood-brain-barrier (BBB) to exert their action on muscle-brain crosstalk. The successful outcomes of this project will have far and broad implications in geroscience. This minimally invasive 3D microphysiological system can be exploited in a variety of studies testing the hallmarks of aging or modeling of age-related diseases in vitro. More importantly, upon validation, the experimental approach used in this proposal can be translated to mimic human parabiosis, which will have significant clinical implications.