Interdependency of fibroadipogenic progenitors and extracellular matrix that drive skeletal muscle fibrosis

驱动骨骼肌纤维化的纤维脂肪祖细胞和细胞外基质的相互依赖性

基本信息

批准号：
10454078
负责人：
LUCAS R SMITH
金额：
$ 47.28万
依托单位：
UNIVERSITY OF CALIFORNIA AT DAVIS
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-04-05 至 2027-03-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10454078
关键词：
Adopted Apoptosis Apoptotic Architecture Area Biocompatible Materials Biopsy Cells Clinical Coculture Techniques Collagen Collagen Fiber Communication Contracts Contracture Defect Development Duchenne muscular dystrophy Dystrophin Engineering Environment Excision Extracellular Matrix Feedback Fibrillar Collagen Fibrosis Gel Genetic Transcription Health Human Impairment In Situ Infusion procedures Injections Injury Interruption Investigation Joints Knowledge Mechanics Mesenchymal Cell Neoplasm Methodology Monitor Mouse Strains Mus Muscle Muscle function Muscle rehabilitation Muscle satellite cell Muscular Dystrophies Myofibroblast Myopathy Natural regeneration Pathologic Pathology Phenotype Prior Therapy Production Profibrotic signal Property Regulation Research Role Signal Transduction Skeletal Muscle Stretching Structure System Testing Tissues Treatment Efficacy Variant Weight-Bearing state Work antifibrotic treatment base crosslink density functional decline functional restoration gene therapy improved functioning in vivo innovation lipid biosynthesis mdx mouse mechanical properties mechanical signal mesenchymal stromal cell micro-dystrophin mouse model muscle regeneration muscle stiffness myogenesis novel prevent progenitor regeneration function regenerative repaired response restoration stem cells success targeted treatment therapy development

项目摘要

PROJECT SUMMARY Fibrosis is the accumulation of extracellular matrix components that disrupt tissue function and is prevalent across many muscle diseases. Muscle functions compromised in fibrosis include muscles primary function to contract as well as its ability to be compliantly stretched when not active. This results in weak and stiff muscle decreasing mobility and producing joint contractures. Skeletal muscle regenerates following injury from resident muscle stem cells, however those cells are sensitive to the organization and mechanics of fibrotic extracellular matrix. Another muscle resident stem cell, fibro-adipogenic progenitors, support myogenesis following injury, but in the context of fibrosis contribute to the pathologic buildup of extracellular matrix. However, the sensitivity of fibro-adipogenic progenitors to their mechanical environment is unknown. Nor is it known how fibro-adipogenic progenitors production of extracellular matrix signals to muscle stem cells to support or impair myogenesis. In order to target effective anti-fbrotic therapies the mechanisms that of communication between fibro-adipogenic progenitors and the extracellular matrix that defines fibrosis must be revealed. Further, the fibrotic environment can act as a barrier to restorative gene therapies for muscular dystrophy, but how fibrosis may influence the efficacy of promising gene therapies is unknown. Fibrosis is particularly common in Duchenne muscular dystrophy, with associated joint contractures. Yet, even removal of functional dystrophin from more fibrotic mouse strains yields a less severe fibrosis, motivating a conjunction of studies in both mice and humans. Fibro-adipogenic progenitors can be activated into pro- fibrogenic cells to resist apoptotic signals and produce excessive extracellular matrix components. This fibrotic extracellular matrix is mainly made of fibrillar collagen, which is the dominant load-bearing structure within healthy and fibrotic extracellular matrix. However, the organization of collagen fibers in the extracellular matrix can alter both the mechanics and adherent cell phenotypes. Fibro-adipogenic progenitors are similar to mesenchymal stromal cells, yet how extracellular matrix organization and mechanical signals drive conversion to the pro-fibrotic state are not known. Nor is it known how one of the primary functions of fibro-adipogenic progenitors, to secrete extracellular matrix, impacts the muscle stem cells responsible for myogenesis. This the potential to create a positive feedback cycle between fibro-adipogenic protenitors and the extracellular matrix. Promising gene therapy using micro-dystrophin is able to largely restore the integrity of myofibers. However, it isn’t known if once the pro-fibrotic cycle is in place if restoring the myofiber integrity and the initiating signals of fibrosis will be sufficient to reverse prominent fibrosis and the associated decline in function. Thus, our objective is to reveal fibro-adipogenic progenitors-based extracellular matrix contribution to functional decline and lack of regeneration in fibrosis along with the potential to reverse fibrosis in muscular dystrophy. In Aim 1, we will utilize a combination of engineered gels and native decellularized matrices to mimic health and fibrosis to determine both the architectural and mechanical features of a cell substrate that directs fibro- adipogenic progenitor fate. In Aim 2, we will induce pro-fibrotic or pro-regenerative fibro-adipogenic progenitor synthesis of extracellular matrices to determine how their structure influences muscle stem cell myogenesis in fibrosis. In Aim 3, micro-dystrophin gene therapy will be administered to before and after the onset of fibrosis to stratify the functional efficacy and change in fibrosis based on the initial stage of fibro-adipogenic progenitors and fibrosis. Success in these Aims will establish the mechanisms fibro-adipogenic progenitors and extracellular matrix interact to perpetuate progressive fibrosis and identify specific targets for anti-fibrotic therapy development that can restore function and enhance the efficacy of restorative gene therapy in muscular dystrophies.

项目摘要纤维化是破坏组织功能的细胞外基质成分的积累，并且普遍存在在许多肌肉疾病中。纤维化中损害的肌肉功能包括肌肉的主要功能合同及其在不活跃时合规伸展的能力。这导致肌肉弱和僵硬降低移动性并产生联合合同。居民受伤后骨骼肌再生肌肉干细胞，但是这些细胞对细胞外纤维化的组织和力学敏感矩阵。另一个肌肉常住的干细胞，纤维辅助祖细胞，支持造成肌发生后的肌发生，但在纤维化的背景下，有助于细胞外基质的病理积累。但是，对机械环境的纤维辅助祖细胞尚不清楚。它也不知道纤维辅助如何祖细胞基质信号的祖细胞产生肌肉干细胞以支持或损害肌发生。在为了靶向有效的抗纤维疗法，纤维辅助之间通信的机制必须揭示祖细胞和定义纤维化的细胞外基质。此外，纤维化环境可以充当肌肉营养不良的恢复性基因疗法的障碍，但纤维化如何影响承诺的基因疗法的功效尚不清楚。纤维化尤其常见于杜尚肌肉营养不良，并伴有关节染色。但是，甚至从更纤维化的小鼠菌株中去除功能性肌营养不良蛋白会产生不太严重的纤维化，激发了小鼠和人类研究的结合。纤维辅助祖细胞可以被激活纤维化细胞可抵抗凋亡信号并产生过多的细胞外基质成分。这种纤维化细胞外基质主要由原纤维胶原蛋白制成，该胶原蛋白是在健康和纤维化的细胞外基质。但是，细胞外基质中的胶原蛋白纤维的组织可以改变力学和粘附细胞表型。纤维辅助祖细胞与间充质基质细胞，但是细胞外基质组织和机械信号如何驱动转换对促纤维化状态尚不清楚。它也不知道纤维辅助的主要功能之一祖细胞，秘密细胞外基质会影响负责肌发生的肌肉干细胞。这个在纤维辅助保护器和细胞外基质之间创建正反馈周期的潜力。使用微肌性的有前途的基因疗法能够在很大程度上恢复肌纤维的完整性。但是，它如果恢复肌纤维完整性和启动信号纤维化将足以逆转明显的纤维化和功能下降。那，我们的目标是为了揭示基于纤维辅助祖细胞基于功能下降和缺乏功能下降的细胞外基质贡献纤维化的再生以及肌营养不良症中纤维化的潜力。在AIM 1中，我们将利用工程凝胶和本地脱细胞矩阵的组合来模仿健康和纤维化以确定指导纤维 - 脂肪生物祖细胞命运。在AIM 2中，我们将诱导促纤维化或促纤维纤维辅助祖细胞综合细胞外物质，以确定其结构如何影响肌肉干细胞肌发生纤维化。在AIM 3中，微肺炎基因疗法将在纤维化发作之前和之后进行根据纤维辅助祖细胞的初始阶段对功能效率和纤维化的变化进行分层和纤维化。这些目标的成功将建立机制纤维辅助祖细胞和细胞外基质相互作用，以永久性纤维化并确定抗纤维化疗法发展的特定靶标这可以恢复功能并提高肌肉营养不良的恢复性基因治疗的效率。