Epitenon-derived progenitor cells in tendon healing and adaptation

项目摘要 这份K99/R00 NIH通向独立奖的申请概述了研究、培训和职业生涯 发展计划，将为安妮·尼科尔斯博士在以下领域的职业生涯做好准备 肌腱细胞机械生物学。该研究项目旨在培训尼科尔斯博士使用尖端技术 转录分析和深入的机械测试技术，以回答关于 外膜的作用，一个围绕着所有肌腱的特征不佳的结构。虽然被认为是为许多人服务的 由于缺乏基因，外膜蛋白的真实身份和功能仍然难以捉摸 专门针对外膜细胞的标记。在初步研究中，尼科尔斯博士发现了一种新的、异质的、 肌腱外膜中GLAST系(GLASTLin)细胞的数量与术后肌腱愈合的关系 急性损伤和肌腱适应在机械超负荷时分化为硬化症(SCX)- 表达肌腱细胞。外膜细胞遗传标记的鉴定及其分子生物学特性的研究 肌腱分化的能力为肌腱研究开辟了一条令人兴奋的新途径，将形成 这是尼科尔斯博士独立研究计划的基础。本提案中概述的目标将建立在这些基础上 初步研究并利用Dr。 Nichols检验GLASTLin外膜细胞是肌腱发生不可或缺的来源这一中心假说 肌腱愈合和适应的祖细胞。在这个奖项的K99阶段，她将定义 不同的GLASTLIN外膜亚群，并鉴定作为韧化祖细胞的特定亚群 集合(目标1)并证明GLASTLin外膜细胞是肌腱正常愈合所必需的(目标2)。在.期间 在R00阶段，Nichols博士将建立GLASTlin外膜细胞和腱细胞之间的协调作为关键 适应性肌腱生长的影响因素(目标3)。总体而言，这些数据将提供第一个全面的 外膜细胞的特性及其在肌腱生物学中的作用。除了严格的科学训练 计划，在城市发展中心的职业发展活动，如赠款撰写研讨会，实验室指导和教学 K99阶段的经验将为Nichols博士在R00阶段过渡到教员职位做好准备。Dr。 尼科尔斯还将从她所组建的集体科学专业知识和职业建议中受益匪浅 科学指导和职业发展咨询委员会(SMCDAC)。除了遗传老鼠 她的主要导师Alayna Loiselle博士的模型和空间RNA测序专业知识与她的互动 SMCDAC将允许Nichols博士在单细胞转录分析方面获得更多专业知识(Chia博士- 机械测试技术(Mark Buckley博士)和肌腱适应模型(Lou博士 Soslowsky)。在SMCDAC职业顾问(Soslowsky博士、Laura Calvi博士、 和Robert Dirksen)，Nichols博士将做好充分准备，成功竞争教职并领导她 拥有独立的研究项目。

Project Summary This K99/R00 NIH Pathway to Independence Award application outlines the research training and career development plan that will prepare Dr. Anne Nichols for a career as an independent investigator in the field of tendon cell mechanobiology. The research project is designed to train Dr. Nichols in the use of cutting-edge transcriptomic analyses and in-depth mechanical testing techniques to answer fundamental questions about the role of the epitenon, a poorly characterized structure surrounding all tendons. Though thought to serve many important functions, the true identity and function of the epitenon has remained elusive due to a lack of genetic markers that specifically target epitenon cells. In preliminary studies, Dr. Nichols identified a novel, heterogenous, population of GLAST-lineage (GLASTLin) cells in the epitenon that contribute to both tendon healing following acute injury and tendon adaptation in response to mechanical overload by differentiating into scleraxis (Scx)- expressing tenocytes. Identification of a genetic marker for epitenon cells as well as demonstration of their capacity for tenogenic differentiation has opened an exciting new avenue of tendon research that will form the basis of Dr. Nichols’ independent research program. The aims outlined in this proposal will build on these preliminary studies and make use of the numerous sophisticated genetic mouse models developed by Dr. Nichols to test the central hypothesis that GLASTLin epitenon cells are an indispensable source of tenogenic progenitor cells for both tendon healing and adaptation. During the K99 phase of this award, she will define the various GLASTLin epitenon subpopulations and identify the specific subset that serves as a tenogenic progenitor pool (Aim 1) and demonstrate that GLASTLin epitenon cells are required for proper tendon healing (Aim 2). During the R00 phase, Dr. Nichols will establish coordination between GLASTLin epitenon cells and tenocytes as a key effector of adaptive tendon growth (Aim 3). Collectively, these data will provide the first comprehensive characterization of epitenon cells and their function in tendon biology. In addition to a rigorous scientific training plan, career development activities at URMC, such as grant-writing workshops, lab mentorship, and teaching experience during the K99 phase will prepare Dr. Nichols to transition to a faculty position in the R00 phase. Dr. Nichols also will benefit greatly from the collective scientific expertise and career advice of her assembled Scientific Mentoring and Career Development Advisory Committee (SMCDAC). In addition to the genetic mouse model and spatial RNA-sequencing expertise of her primary mentor, Dr. Alayna Loiselle, interaction with her SMCDAC will allow Dr. Nichols to acquire additional expertise in single-cell transcriptomic analyses (Dr. Chia- Lung Wu), mechanical testing techniques (Dr. Mark Buckley), and models of tendon adaptation (Dr. Lou Soslowsky). With the help and critical feedback of her SMCDAC career advisors (Drs. Soslowsky, Laura Calvi, and Robert Dirksen), Dr. Nichols will be well-prepared to successfully compete for faculty positions and lead her own independent research program.