The role of collagen organization in determination of fibrotic muscle function and regeneration

 描述(申请人提供)：我的长期职业目标是成为一名独立的学术研究人员，在肌肉生理学领域做出实质性贡献，这些贡献被转化为肌肉疾病患者的临床相关疗法。这一奖励机制将有助于提供实现目标的能力，为我提供过渡到独立所需的持续培训。我在生物工程和肌肉生理学研究方面的背景为我提供了一个突出的问题，即肌肉纤维化如何导致功能受损和再生。为了充分解决这个问题，我得到了生物工程领域一位杰出导师的支持，他是细胞对细胞外基质特性的反应。他的指导将得到我的合作导师巴顿博士的补充，他将继续在肌肉生理学方面提供出色的指导。索斯洛夫斯基博士将提供进一步的指导，他将在我的顾问委员会任职。该委员会将定期开会，以确保在项目里程碑方面取得足够的进展，必要时评估替代战略，并监督我向独立的过渡。我还将与合作伙伴合作：岩本博士，他在严重肌肉损伤模型方面拥有专业知识，以及山内博士，他是胶原蛋白转录后修饰方面的权威。宾夕法尼亚大学的环境非常适合进行这项拟议的研究，主要来自宾夕法尼亚肌肉研究所，该研究所为对肌肉的各个方面感兴趣的一批积极参与的教职员工提供各种培训机会。在奖项的指导阶段，教学将扩大我的研究范围，并降低在我的职业生涯中尝试新方法的障碍。宾夕法尼亚州立大学还为博士后获得教师职位提供支持服务，我将通过生物医学博士后项目办公室充分利用这些服务。宾夕法尼亚大学杰出的机构环境将得到佛罗里达大学与共同导师巴顿博士的培训和北卡罗来纳大学与合作者山内博士的培训的补充。拟议的这项研究的结果将通过同行评议的出版物和在有相关利益的国家会议上的发言与公众分享。虽然我会领导这件事 在这个项目中，所采用的支持系统将确保每一个成功实现我的目标的机会。纤维化是细胞外基质(ECM)成分在组织内的病理性积聚，导致结构紊乱和功能丧失。骨骼肌在许多情况下都会发生纤维化，包括肌肉营养不良和严重的肌肉损伤。在骨骼肌中，细胞外基质不仅提供细胞支架，还具有传递肌肉纤维产生的力量的额外作用，使细胞外基质对肌肉功能至关重要。我过去对骨骼肌的研究已经证明了纤维化是如何在许多情况下损害肌肉的，但也突显了人们对纤维化材料的结构知之甚少。 纤维组织主要由纤维状胶原组成，但胶原量不能决定损伤的程度，提示进一步的胶原蛋白组织参数起着重要作用。由于目前还没有被批准的治疗方法来治疗骨骼肌纤维化，我的长期目标是创建治疗靶点和测试骨骼肌抗纤维化药物的框架。我的中心假设是，胶原组织的参数在纤维化过程中被破坏，包括交联、排列和堆积，这种破坏损害了肌肉功能和再生。我还将测试抑制纤维化肌肉中的交叉连接将减少纤维化、改善功能和再生的假设。我的目标是定义骨骼肌纤维化胶原组织的新参数，并对该组织进行操作，以探索肌肉再生并提供治疗靶点。在K99部分的资助期间，我将追求目标1：确定肌肉纤维化中胶原组织是如何改变的。我们将确定ECM组织参数、胶原交联度、胶原排列和胶原堆积与主动和被动肌肉功能的关系。我们将验证这一假设，即在骨骼肌纤维化中，胶原组织而不仅仅是胶原量发生了变化。在奖项的指导阶段，我将获得基质工程和干细胞生物学方面的新技能，以便在R00阶段追求目标2：确定胶原组织如何影响卫星细胞再生。我推测胶原蛋白组织受损的基质上的卫星细胞成熟会受到损害。最后，在K99期间，我将优化一个治疗方案，以在R00阶段进行测试，从而实现目标3：确定抑制胶原交联是否能改善肌肉纤维化的功能和再生。我将验证一种假设，即β-氨基丙腈，一种交叉连接的抑制剂，可以作为一种有效的抗纤维化治疗。这些研究将利用我以前在肌肉生理学方面的研究专长，但也需要在组织培养中进行肌肉胶原分析和基质基质工程方面的培训。在本项目结束时，我将能够确定骨骼纤维化中胶原组织的关键特征 肌肉及其与肌肉功能和卫星细胞再生的关系。我还将提供靶向胶原组织作为治疗骨骼肌纤维化的潜在疗法的证据。这项研究将为我作为一名独立科学家的职业生涯奠定基础，这一奖项提供的指导培训使我成为可能。

 DESCRIPTION (provided by applicant): My long term career goal is to become an independent academic researcher, making substantial contributions in the field of muscle physiology that are translated into clinically relevant therapies for those with muscle diseases. This award mechanism would be instrumental in the providing the ability to reach goal by providing the continued training necessary for me to transition to independence. My background in bioengineering and muscle physiology research has provided a focus on outstanding question of how muscle fibrosis leads to impaired function and regeneration. To adequately address this question I have garnered the support of an outstanding mentor in bioengineering of cellular responses to extracellular matrix properties, Dr. Discher. His mentorship will be supplemented by that of my co-mentor Dr. Barton, who will continue to provide exceptional mentorship in muscle physiology. Further guidance will be provided by Dr. Soslowsky, who will serve on my advisory committee. This committee will meet regularly to ensure adequate progress toward project milestones, assess alternative strategies when necessary, and monitor my transition to becoming independent. I will also work with collaborators; Dr. Iwamoto who has expertise in severe muscle injury models and Dr. Yamauchi who is an authority on collagen post-transcriptional modifications. The environment at Penn is ideal for conducting the proposed research, in large part from the Pennsylvania Muscle Institute which provides various training opportunities among a cadre of engaged faculty interested in a variety of aspects of muscle. Didactics during the mentored phase of the award will broaden the scope of my research and lower barriers to attempting new approaches in my career. Penn also provides support services for postdocs acquiring faculty positions that I will take full advantage of through the Biomedical Postdoctoral Program Office. The outstanding institutional environment at the University of Pennsylvania will be supplemented by training at the University of Florida with co-mentor Dr. Barton and at the University of North Carolina with collaborator Dr. Yamauchi. The results of this research proposed will be shared with the public through peer reviewed publications and presentations at national conferences with relevant interests. While I will take leadership of this project, the support system engaged will ensure every opportunity for success in acquiring my goals. Fibrosis is the pathologic accumulation of extracellular matrix (ECM) components within a tissue leading to disrupted architecture and loss of function. Skeletal muscle undergoes fibrosis in response to many conditions including muscular dystrophies and severe muscle injury. Within skeletal muscle the ECM not only provides a cell scaffold, but has the additional role of transmitting forces produced by muscle fibers, making ECM critical to muscle function. My past research in skeletal muscle has demonstrated how fibrosis compromises muscle in many conditions, but also highlighted how little is known about the structure of fibrotic material. Fibrotic tissue is primarily made of up fibrillar collagen, however the amount of collagen does not determine the degree of impairment, suggesting further parameters of collagen organization play an important role. As there is currently no approved therapeutic to treat skeletal muscle fibrosis, my long term goal is to create therapeutic targets and a frame work for testing anti-fibrotics in skeletal muscle. My central hypothesis is that parameters of collagen organization are disrupted in fibrosis, including cross-linking, alignment, and packing, and that this disruptio impairs muscle function and regeneration. I will also test the hypothesis that inhibiting cross-linking in fibrotic muscle will reduce fibrosis, improve function, and regeneration. My objective i to define new parameters of collagen organization of skeletal muscle fibrosis and manipulate that organization in order to probe muscle regeneration and provide therapeutic targets. During the K99 portion of the grant I will pursue Aim 1: Determine how collagen organization is altered in muscle fibrosis. We will determine how parameters of the ECM organization, collagen cross-linking, collagen alignment, and collagen packing relate to active and passive muscle function. We will test the hypothesis that collagen organization, not just collagen quantity, is altered in skeletal muscle fibrosis. During the mentored phase of the award I will obtain new skills in matrix engineering and stem cell biology in order to pursue in the R00 phase Aim 2: Determine how collagen organization effects satellite cell regeneration. I hypothesize satellite cell maturation on substrates with disrupted collagen organization will be impaired. Finally during the K99 I will optimize a treatment regimen to be tested during the R00 phase leading to Aim 3: Determine if inhibiting collagen cross-linking leads to improved function and regeneration of muscle fibrosis. I will test the hypothesis that β-aminopropionitrile, a cross-linking inhibitor, an be effective as an anti-fibrotic treatment. These studies will take advantage of my previous research expertise in muscle physiology, but also require training in the analysis of muscle collagen and the engineering of matrix substrates in tissue culture. At the conclusion of this project, I will be able to define the key features of collagen organization in fibrosis of skeletal muscle and their relation to muscle function and satellite cell regeneration. I will also provide evidence for targeting collagen organization as a potential therapy to treat skeletal muscle fibrosis. This research will lay the foundation for my career as an independent scientist made possible by the mentored training provided by this award.