Cadherin-Dependent Regulation of Satellite Cell Function

卫星细胞功能的钙粘蛋白依赖性调节

• 批准号: 10297443
• 负责人: Robert S. Krauss
• 金额: $ 56.97万
• 依托单位: ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-07-15 至 2026-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10297443
• 关键词: Adult; Axon; Basal lamina; Binding Proteins; Biological; Cadherins; Cell Communication; Cell physiology; Cells; Cellular Morphology; Cellular biology; Cytoskeleton; Engraftment; F-Actin; Fluorescent Probes; Genetic; Genetic study; Guanosine Triphosphate Phosphohydrolases; Homeostasis; Image; In Vitro; Injury; Knowledge; Maintenance; Methodology; Methods; Microscopy; Microtubules; Minus End of the Microtubule; Molecular; Molecular Analysis; Morphology; Mus; Muscle; Muscle satellite cell; Myoblasts; Myopathy; Natural regeneration; Nature; Neurons; Play; Preparation; Procedures; Process; Proliferating; Property; Protocols documentation; Regenerative Medicine; Regenerative capacity; Regulation; Research; Role; Scanning; Signal Transduction; Signaling Protein; Skeletal Muscle; Structure; Surface; System; Techniques; Testing; Therapeutic; Therapeutic Agents; Time; Tissues; base; cell motility; in vivo; muscle aging; muscle regeneration; novel; novel marker; regeneration following injury; repaired; response; satellite cell; stem cell biology; stem cells

Skeletal muscle has remarkable capacity for regeneration. This capability derives from resident muscle stem cells, called satellite cells (SCs). During adult muscle homeostasis, SCs are quiescent. Upon injury, they are “activated” to generate myoblasts for muscle repair. SCs are localized between myofibers and their surround- ding basal lamina; this niche promotes SC quiescence. Proper regulation of quiescence is necessary for long- term SC function and for successful engraftment of SCs. Therefore, knowledge of how the niche promotes quiescence is critical to harnessing SCs for therapeutic purposes. However, the mechanisms that underlie SC quiescence and the quiescence-to-activation (Q-to-A) transition remain poorly understood. In uninjured muscles in vivo, SCs have long projections. Little is known of these structures, as they are lost during prepara- tion of SCs for study in vitro. We have developed a single myofiber isolation procedure that allows mainten- ance of projections. QSC projections are microtubule (MT)-rich and ringed with cortical F-actin, resembling neuronal axons. Our findings indicate that SC projections are motile, potentially allowing QSCs to scan the surface of the myofiber for damage and/or signals that regulate quiescence vs. activation. Retraction of project- tions occurs upon SC activation and is a very early step in the Q-to-A transition, preceding other known early steps. Cadherins, which are required for quiescence and regulate the Q-to-A transition, are important factors for maintenance of projections. We hypothesize that SC quiescence is a dynamic state, characterized by motile projections regulated by cadherins and the cytoskeleton. We have identified novel factors as candidate regulators of this process, including the GTPase, Rac1; the MT minus-end binding protein, CAMSAP3; and the RhoA GEF, LFC. We will test our hypotheses with a combination of genetic studies in mice and cell biological studies with single myofiber preparations. The following aims are proposed: 1) to determine the roles of Rac1, CAMSAP3, and LFC on SC quiescence and Q-to-A transition, we will construct mice conditionally lacking these factors in adult SCs and assess SC homeostasis, function, and structure in vivo and on single myofibers prepared with our new methods; and 2) to investigate cytoskeletal dynamics of retracting SC projections during the Q-to-A transition, we will adapt live imaging protocols to our single myofiber preparations. Mice with SC- specific expression of fluorescent probes for F-actin and MT dynamics will be employed with time-lapse micro- scopy. The effects of perturbing cadherins, the cytoskeleton, and specific signaling proteins on this initial step of SC activation will be determined. The ability to exploit SCs in muscle therapies requires detailed molecular and cell biological knowledge of SC quiescence and the Q-to-A transition, but they are poorly understood. The proposed aims are highly novel and involve a synergistic combination of genetic and cell biological analyses. They are expected to provide fundamental new information on SC biology. They are therefore anticipated to have a significant impact on the potential use of SCs as therapeutic agents in regenerative medicine.

骨骼肌肉的显着能力。 细胞，称为卫星细胞（SCS）。 “激活”以生成肌肉修复的肌细胞。 丁基层; 术语SC功能和成功的SC的发明。 Quyscence对于用于治疗目的的SC是至关重要的。 静止和静止激活（q-to-a）过渡仍然不受欢迎 体内肌肉，SC的预测很长。 用于体外研究的SC。 QSC预测的ance是微管（MT） - 富含皮质的F-肌动蛋白 神经元素的发现表明SC 肌纤维的表面，以造成损坏和/或信号，使静止与激活相关。 tions发生在SC激活后发生，并且是Q-TO-A过渡的早期一步，在其他已知的早期之前 静态和调节Q-TO-A过渡所需的步骤是重要的因素 为了维持预测。 由钙粘着蛋白和细胞骨架调节的运动投影。 该过程的调节剂，包括gtpase，rac1； Rhoa GEF，LFC。 用单一肌纤维制剂进行的研究。 CAMSAP3和LFC在SC静止和Q-TO-A过渡时，我们将构造有条件缺乏的小鼠 这些因素在成人SC中，并评估SC的中心症，功能和结构在体内和单个肌纤维中 使用我们的新方法和2）研究缩回SC的细胞骨架动力学 Q-to-A过渡，我们将使用SC-的单一肌纤维制剂调整实时成像协议。 F-actin和MT动力学的荧光播种探针的特定表达将使用延时的微观表达 Scopy。 SC激活将确定肌肉疗法中SC的能力。 细胞的生物学知识和to-a过渡的生物学知识，但它们很差 支撑目的是高度新颖的，涉及遗传和细胞生物学分析的协同组合。 他们有望提供有关SC生物学的新信息。 对SCS作为再生医学中的治疗剂的潜在用途有重大影响。