Role of TRPV4 and YAP/TAZ in Tendon Fibrosis and Engineered Tendon Development

项目总结/摘要 在美国，每年有超过30万例肩袖手术。然而，治疗往往是复杂的， 通过纤维化形成的无序胶原基质并导致高的再撕裂率。肌腱组织工程 寻求解决使用生物材料促进新肌腱形成以增强修复或再生的问题 肌腱然而，虽然目前的生物材料提供了改善肌腱愈合的机会，但它们经常 在临床前研究中仍然表现出纤维化。因此，迫切需要了解 在设计肌腱组织工程生物材料时，矩阵架构和 瞬时受体电位阳离子通道亚家族V成员4（TRPV 4）调节排列胶原形成 在体外肌腱形成过程中，但其机制仍有待确定。最近，TRPV 4刺激被 发现诱导核定位和转录辅激活因子Yes相关蛋白（雅普）的激活 在纤维化过程中，在角质形成细胞和肌成纤维细胞中与PDZ结合基序（TAZ）和转录共激活因子。 雅普表达在肌腱发育过程中上调，这一过程的特征是胶原蛋白的排列 形成，并响应生理机械刺激，这表明它可能发挥重要作用， 肌腱TRPV 4和雅普/TAZ在肺、肝、肾和心脏纤维化中均失调。但 TRPV 4和雅普/TAZ的作用以及它们之间的相互作用在肌腱纤维化中或 工程化肌腱开发。总体假设是TRPV 4通过以下途径调节胶原排列： 雅普/TAZ在生物材料上的肌腱形成过程中，刺激新肌腱形成的程度与拉伸相似 加载中相反，雅普/TAZ和TRPV 4之间的这种关系的失调将促进纤维化基质 证词目的1将比较雅普/TAZ和TRPV 4在健康和纤维化肩袖肌腱中的作用。目的2 将研究TRPV 4和雅普/TAZ在肌腱形成过程中对齐胶原形成中的相互作用 在“健康”和“纤维化”条件下的静电纺丝生物材料。目标3将评价TRPV 4刺激 影响生物材料上的新肌腱形成。该信息将直接告知计划的临床前研究， 肩袖修复最初在啮齿动物模型中进行，如果成功，则转移到大型动物模型和临床 翻译.完成拟议的研究将为我提供机会和培训，以支持我的 职业目标和发展的技能，我需要实现我的长期目标，一个独立的教师职业生涯在一个 研究密集型机构。

Project Summary/Abstract More than 300,000 rotator cuff surgeries occur annually in the US. However, treatment is often complicated by disorganized collagen matrix formed via fibrosis and results in high re-tear rates. Tendon tissue engineering seeks to solve the problem using biomaterials to promote neo-tendon formation to augment repair or regenerate tendon. However, while current biomaterials provide the opportunity to improve tendon healing, they frequently still exhibit fibrosis in preclinical studies. Therefore, a critical need exists to understand the mechanisms of aligned collagen formation when designing biomaterials for tendon tissue engineering. Matrix architecture and transient receptor potential cation channel subfamily V member 4 (TRPV4) regulate aligned collagen formation during tenogenesis in vitro, but the mechanism remains to be determined. Recently, TRPV4 stimulation was found to induce nuclear localization and activation of transcriptional co-activators Yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif (TAZ) in keratinocytes and myofibroblasts during fibrosis. YAP expression is upregulated during tendon development, a process characterized by aligned collagen formation, and in response to physiological mechanical stimulation, suggesting it could play an important role in tendon. Both TRPV4 and YAP/TAZ are dysregulated in lung, liver, kidney, and cardiac fibrosis. However, the role of TRPV4 and YAP/TAZ, and their interactions, have not been investigated in tendon fibrosis or during engineered tendon development. The overall hypothesis is that TRPV4 regulates collagen alignment via YAP/TAZ during tenogenesis on biomaterials and stimulates neo-tendon formation to a similar extent as tensile loading. In contrast, dysregulation of this relationship between YAP/TAZ and TRPV4 will promote fibrotic matrix deposition. Aim 1 will compare the role of YAP/TAZ and TRPV4 in healthy and fibrotic rotator cuff tendon. Aim 2 will investigate the interaction between TRPV4 and YAP/TAZ in aligned collagen formation during tenogenesis on electrospun biomaterials in ‘healthy’ and ‘fibrotic’ conditions. Aim 3 will evaluate how TRPV4 stimulation affects neo-tendon formation on biomaterials. This information will directly inform planned preclinical studies of rotator cuff repair initially in rodent models, before, if successful, moving to large animal models and clinical translation. Completing the proposed studies will provide me with the opportunities and training to support my career goals and develop the skills I need to achieve my long-term goal of an independent faculty career at a research-intensive institution.