Effect of exercise on skeletal muscle-derived extracellular vesicles and regulation of mitochondrial biogenesis

运动对骨骼肌源性细胞外囊泡的影响及线粒体生物发生的调节

• 批准号: RGPIN-2022-05252
• 负责人: Saleem, Ayesha
• 金额: $ 2.26万
• 依托单位: University of Manitoba
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=757783
• 关键词: Effect; exercise; skeletal; muscle; derived

Skeletal muscle (SkM) is highly adaptable and plays a critical role in determining whole-body metabolic capacity. The gold standard response to chronic exercise (CE) is an increase in mitochondrial content & activity termed mitochondrial biogenesis (MB). While mechanisms regulating MB within SkM have been studied extensively, less is known about how SkM drives systemic adaptations. The lion's share of attention has been attributed to proteins released from SkM termed myokines, that can be released directly, or packaged in carrier vehicles called extracellular vesicles (EVs) to ferry them in the circulatory system. EVs are an evolutionary conserved method of intercellular communication, are released from all cells and contain biochemical cargo that can modify function in recipient cells. Previous work has shown that CE promotes an increase in systemic EV concentration, changes EV cargo, and that these EVs evoke protective adaptations. However, these EVs were mostly obtained from serum/plasma which contain EVs from all tissues in the body. The effect of CE specifically on SkM-EVs, and their role in mediating systemic adaptations to CE e.g. MB remains unknown. This is a critical gap in knowledge, as SkM is one of the largest organ systems, performs the physical work during CE, a reservoir of myokines, and known to regulate metabolic performance. I hypothesize that CE modifies SkM-EVs and that these SkM-EVs can mediate an increase in MB. Novel and exciting pilot data from my lab support this hypothesis. My NSERC DG research program will use cutting-edge molecular biology techniques to address this gap. We will use an in vitro model of chronic contractile activity (CCA) to isolate and measure SkM-EVs using established & validated techniques. SkM-EVs will be co-cultured with other cells, and changes in MB measured. We will genetically modify SkM cells to express a specific enzyme (cre), subject them to CCA, isolate EVs and inject into a double-reporter mouse. In this model, tissues that take up SkM-EVs will switch from red to green fluorescence. Since only the SkM-EVs contain the cre enzyme, this model will allow us to quantitatively track SkM-EVs in vivo post-CCA. Metabolically-active tissues will be harvested, EV uptake confirmed and changes in MB evaluated post-chronic treatment with CCA-SkM-EVs. Thus, my HQP will determine the effect of CCA on SkM-EVs & discover whether SkM-EVs can regulate MB using innovative and mechanistic techniques. The short-term results will lead to landmark discoveries that will create new knowledge about the effects of CCA on SkM-EVs and their effect on MB. The long-term goals of my NSERC DG research program are to elucidate upstream mechanisms of SkM-EV biogenesis, release and uptake, and downstream signalling pathways that mediate MB. My program will fuel interdisciplinary research with biotechnology and applied physiology fields to advance knowledge, benefit and accelerate Canadian research and promote HQP training.

骨骼肌 (SkM) 具有高度适应性，在确定全身代谢能力 (CE) 方面发挥着关键作用，其黄金标准反应是线粒体含量和活性（称为线粒体生物发生 (MB)）的增加，同时调节 MB 的机制。人们对 SkM 内部的肌动蛋白进行了研究，但人们对 SkM 如何驱动系统适应知之甚少。在循环系统中运送它们的细胞外囊泡 (EV) 是一种进化保守的细胞间通讯方法，从所有细胞中释放出来，并含有可以改变受体细胞功能的生化物质。全身性 EV，改变 EV 货物，并且这些 EV 引起保护性适应。然而，这些 EV 浓度主要是从含有来自体内所有组织的 EV 的血清/血浆中获得的。 SkM-EV 及其在介导 CE 系统适应（例如 MB）中的作用仍然未知，这是知识上的一个关键差距，因为 SkM 是最大的器官系统之一，在 CE 期间执行体力工作，是肌因子的储存库。我假设 CE 会改变 SkM-EV，并且这些 SkM-EV 可以介导 MB 的增加，我的实验室的新颖且令人兴奋的试验数据支持了这一假设。 NSERC DG 研究计划将使用尖端的分子生物学技术来解决这一差距，我们将使用慢性收缩活动 (CCA) 的体外模型来分离和测量 SkM-EV，并使用已建立和验证的技术。 -与其他细胞一起培养，并测量 MB 的变化。我们将对 SkM 细胞进行基因改造，使其表达特定的酶 (cre)，对它们进行 CCA，分离 EV 并注射到双报告小鼠的组织中。由于只有 SkM-EV 含有 cre 酶，因此该模型将允许我们定量跟踪 CCA 后体内的 SkM-EV，即收获的代谢活性组织。确认摄取并评估 CCA-SkM-EV 慢性治疗后的 MB 变化，因此，我的 HQP 将确定 CCA 对 SkM-EV 的影响，并发现 SkM-EV 是否可以使用调节 MB。短期结果将带来里程碑式的发现，从而创造关于 CCA 对 SkM-EV 的影响及其对 MB 的影响的新知识。我的 NSERC DG 研究计划的长期目标是阐明上游。 SkM-EV 生物发生、释放和摄取的机制，以及介导 MB 的下游信号传导途径总部培训。