Engineered Heterochronic Parabiosis on 3D Microphysiological Systems

项目概要 异时性联体共生，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“反老年”因素的证据，但循环因素介导的机制 肌肉干细胞及其微环境的恢复活力特性尚未阐明。由于 体内联体共生的复杂性和血源性因素的动态性质，可靠地识别这些 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 先进的微工程方法来构建可以控制机械的 3D 微流体联生电路 以及生理相关 3D 微环境中的生化线索。在这项提案中，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完善和升级体外联体共生平台 （MetRSL2774G 转基因）精确识别肌肉分泌组，也称为肌因子，负责 对肌肉干细胞的年轻化作用。此外，将采用靶向遗传学方法 描述氧化应激诱导的前老年肌因子对肌肉干细胞功能产生负面影响。 最后，该团队还将在芯片上联体共生中设计一个运动诱发的肌因子报告系统 使用与蛋白质标记构建体 MetRSL274G 共表达的光遗传学致动器（视紫红质通道 2）。 利用该记者，拟议的研究将鉴定具有抗老年特性的新型收缩诱导肌因子 以及穿过血脑屏障（BBB）对肌脑串扰发挥作用的肌因子。的 该项目的成功成果将对老年科学产生深远而广泛的影响。这种微创 3D 微生理系统可用于测试衰老特征或建模的各种研究 年龄相关疾病的体外研究。更重要的是，经过验证，本研究中使用的实验方法 该提案可以转化为模仿人类联体共生，这将具有重大的临床意义。

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.