Electrical Stimulation of Human Myocytes in Microgravity: An In Vitro Model to Evaluate Therapeutics to Counteract Muscle Wasting

项目摘要 本授权申请是对RFA-TR-18-001“NIH-CASIS协调微生理系统”的回应。 空间转化研究计划”，提出了一个杰出的合作努力， Sanford Burnham Prebys医学发现研究所、SpacePharma公司、佛罗里达医院的研究人员 佛罗里达大学代谢与糖尿病转化研究所 生物医学工程和空间技术与高级研究系统（STaARS）。宇航员 在长时间的太空飞行后肌肉退化。这些影响在很大程度上是可逆的;然而， 随着年龄增长观察到的骨骼肌内在变化，如DNA损伤、细胞应激、线粒体 功能障碍和衰老可能与微重力引起的细胞机制重叠。因此，在本发明中， 利用人体组织模拟疾病状况的微重力研究可能大大有助于发展 临床相关的方法来解决老年人的肌肉萎缩，称为肌肉减少症。的 60岁以上的老年人数量正以前所未有的速度增长，从全球人口的11%左右， 到2050年，人口将达到21%。治疗选择，以治疗肌肉减少症是相对不存在的部分 由于对控制与年龄相关的骨骼肌的机制的不完全理解， 功能障碍我们的团队一直致力于开发一个毫流控芯片实验室系统， 微重力下骨骼肌细胞生长和基因表达变化。我们建立了文化 从年轻、健康和老年、久坐不动的志愿者中分离的原代人肌细胞的条件， 生物学数据表明细胞保留了供体组织的表型。此外，我们有 制作了一个具有多个培养室的飞行准备芯片。对于这项建议，我们计划纳入 将电极插入芯片中，并通过模拟确定电场强度分布，以优化用于 电刺激嵌入天然模拟细胞外基质中的肌细胞。我们的实验室 芯片将被集成到一个远程控制的，完全自动化的实验室解决方案中， 处理系统，光学检测系统，以记录收缩，和一个软件平台，近实时 在STaARS-1实验飞行设施内的国际空间站上控制实验。在随后的航班上， 我们建议在经验证的芯片实验室系统中测试具有抗萎缩特性的天然产物。药物 通过添加能够递送给肌细胞的给药口 多种药物稀释。我们的下一代芯片实验室系统将成为小型化实验室的领导者 研究微重力引起的肌肉组织病理生理变化的疾病模型， 推进药物疗效和治疗剂的毒理学测试，以提高肌肉萎缩的负担。

PROJECT SUMMARY This grant application, in response to RFA-TR-18-001 “NIH-CASIS Coordinated Microphysiological Systems Program for Translational Research in Space”, proposes an outstanding collaborative effort among investigators at Sanford Burnham Prebys Medical Discovery Institute, SpacePharma, INC, Florida Hospital Translational Research Institute for Metabolism and Diabetes, the University of Florida Department of Biomedical Engineering and Space Technology and Advanced Research Systems (STaARS). Astronauts suffer from muscle degeneration after prolonged spaceflight. These effects are largely reversible; however, the intrinsic changes in skeletal muscle observed with age such as DNA damage, cellular stress, mitochondrial dysfunction and senescence are likely to overlap with cellular mechanisms induced in microgravity. Thus, studies in microgravity using human tissue to model disease conditions may greatly contribute to development of clinically relevant approaches to address muscle wasting in the elderly referred to as sarcopenia. The number of elderly individuals over the age of 60 is growing at an unprecedented rate from ~11% of the global population today to ~21% by 2050. Therapeutic options to treat sarcopenia are relatively non-existent in part because of an incomplete understanding of the mechanisms controlling age-related skeletal muscle dysfunction. Our team has been focused on developing a millifluidic lab-on-a-chip system to study human skeletal muscle cell growth and gene expression changes in microgravity. We have established culture conditions for primary human myocytes isolated from young, healthy and older, sedentary volunteers and have biological data indicating that the cells retain the phenotype of the donor tissue. Furthermore, we have fabricated a flight ready chip with multiple culture chambers. For this proposal, we plan to incorporate electrodes into the chip and determine electric field strength distribution by simulation to optimize conditions for electrically stimulating muscle myocytes embedded in a native mimicking extracellular matrix. Our lab-on-a- chip will be integrated into a remote controlled, fully automated laboratory solution complete with a fluid handling system, an optical detection system to record contraction, and a software platform for near real-time control of the experiment on the ISS housed in STaARS-1 experimental flight facility. On a subsequent flight, we propose to test natural products with anti-atrophy properties in the validated lab-on-a-chip system. Drug delivery to the muscle cultures will be facilitated via the addition of an administration port capable of delivering multiple drug dilutions. Our next generation lab-on-a-chip system stands to be a leader in miniaturized lab disease modeling to study pathophysiological changes in muscle tissue induced in microgravity intended to advance drug efficacy and toxicological testing of therapeutics to elevate the burden of muscle wasting.