Understanding Regulators of Collagen Crosslinking Enzymes for Tendon Formation

肌腱是肌肉和骨骼之间的机械连接。了解肌腱如何发展机械功能是很重要的，因为肌腱损伤很常见，治疗选择有限，受损的肌腱很少能完全恢复力量。胶原蛋白是肌腱强度的主要贡献者。然而，在正常肌腱发育过程中，影响胶原形成的条件尚不清楚。例如，几种类型的酶在肌腱中交联并稳定胶原蛋白，但细胞在肌腱发育过程中如何协调这些胶原交联酶的产生尚不清楚。该项目通过探索控制细胞酶生产的信号来解决这一知识差距。这项研究将产生关于胶原交联如何被调节的新知识。这项研究的发现将有助于更好地理解肌腱形成的机制，并可能导致先进的治疗方法来治疗肌腱损伤引起的机械功能改变和残疾。该项目包括提高STEM毕业生的保留率和工程专业毕业生的多样性的活动。该项目为参加多学科工程课程的学生创造了动手研究经验和写作练习。它还资助本科生进行教师指导的研究，开发和提交NSF研究生研究奖学金申请，并在科学会议上展示他们的研究。最后，该项目包括K-12外展活动和实验室参观。本研究的科学目标是确定控制细胞产生胶原交联酶的机制。从发育中的大鼠肌腱中分离出的成体干细胞和肌腱细胞与强外力（跟腱）和弱外力（尾腱）相关，将在培养中作为模型系统进行评估，以确定这些细胞群是否具有独特的控制机制。为了测试调节胶原交联酶产生的机械反应途径，细胞将使用生物反应器暴露于一系列机械刺激下，并使用靶向细胞信号通路抑制剂进行处理。在进行细胞信号通路抑制和分析的同时，将使用已知影响肌腱生长和损伤的不同生化生长因子来评估生物信号在酶生产中的作用。研究结果将促进对肌腱和干细胞调节胶原交联酶产生的机制的认识。该项目由生物力学和机械生物学（BMMB）计划和促进竞争性研究的既定计划（EPSCoR）共同资助。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Tendons act as a mechanical connection from muscle to bone. Understanding how tendons develop mechanical function is important because tendon injuries are common, treatment options are limited, and damaged tendons rarely regain their full strength. Collagen is a major contributor to tendon strength. However, much is unknown about the conditions that influence collagen formation during normal tendon development. For example, several types of enzymes crosslink and stabilize collagen in tendons, but how cells coordinate the production of these collagen crosslinking enzymes during tendon development is unknown. This project addresses this knowledge gap by exploring the signals that control enzyme production by cells. This research will generate new knowledge on how collagen crosslinking is regulated. Findings from this research will contribute to a greater understanding of the mechanisms of tendon formation and may lead to advanced therapies to treat the altered mechanical function and disability found with tendon injuries. Integral to the project are activities to improve retention in STEM and the diversity of graduates in engineering. The project creates hands-on research experiences and the writing exercises for students enrolled in a multidisciplinary engineering course. It also funds undergraduates to conduct faculty-mentored research, develop and submit NSF graduate research fellowship applications, and present their research at scientific conferences. Finally, the project includes K-12 outreach activities and laboratory tours.The scientific goal of this research is to define the mechanisms that control collagen crosslinking enzyme production by cells. Adult stem cells and tendon cells isolated from developing rat tendons associated with high forces, the Achilles tendon, and low forces, the tail tendon, will be evaluated in culture as model systems to determine if these cell populations have unique control mechanisms. To test mechanically responsive pathways that regulate collagen crosslinking enzyme production, cells will be exposed to a range of mechanical stimuli using a bioreactor and treated with targeted cell signaling pathway inhibitors. The role of biological signaling in enzyme production will be evaluated using different biochemical growth factors that are known to impact tendon growth and injury, while conducting cell signaling pathway inhibition and analysis. Research outcomes will advance knowledge of the mechanisms that regulate collagen crosslinking enzyme production by tendon and stem cells. This project is jointly funded by Biomechanics & Mechanobiology (BMMB) Program and the Established Program to Stimulate Competitive Research (EPSCoR).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.