Endosomal trafficking and functions in cardiomyocytes: insights from Arf6 signaling

心肌细胞内体运输和功能：Arf6 信号传导的见解

• 批准号: RGPIN-2019-06810
• 负责人: AugerMessier, Mannix
• 金额: $ 2.33万
• 依托单位: Université de Sherbrooke
• 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=760581
• 关键词: Endosomal; trafficking; functions; cardiomyocytes; insights

The long-term vision of our research program is to better understand a fundamental trafficking mechanism that dictate how some proteins reach the surface of contractile cells from the heart, namely the cardiomyocytes. To achieve such goal, we first propose to study, by genetic manipulation of mice, how the removal of a protein named Arf6, an important regulator of protein trafficking in other cells, is impacting heart function. Cell-surface proteins affected by the removal of Arf6 will be further analysed to establish how Arf6 impacts the localization and/or degradation of these proteins and how it affects their function at the membrane of cardiomyocytes. Moreover, we will investigate the role of Arf6 in the genesis and release of cardiac-derived exosomes, which are small vesicles released by cardiomyocytes in their immediate environment and the general circulation before being uptake by other cells. Notably, we will determine how the absence of Arf6 affects the number of exosomes released by cardiomyocytes, but also their protein and miRNA content using unbiased proteomic assays and miRNA screens, respectively. Surprisingly, while this conserved communication system between cells has gained interest in the past years, the mechanisms involved in the production of these exosomes are not yet completely understood. Hence, we expect that our findings will deepen our knowledge about the cardiac endosomal and exosomal trafficking, a fundamental but still enigmatic cellular process in cardiomyocyte's biology. The discoveries originating from this research program will provide benefits to multiple individuals and groups. First, the highly qualified personnel (HQP) formed in my laboratory will benefit from a stimulating research environment. These HQP will become expert in cardiac biology, molecular signaling, genetic manipulation, and related state of the art technology, like echocardiography assessment of murine model, to address the most pressing challenges in the cardiac research field. Also, considering the growing interest in fundamental cardiovascular research and the novel aspects of this research program, we believe our discoveries will generate transposable knowledge that will lead forward the hypothesis and discoveries of other research groups in their own field of expertise.

我们研究计划的长期愿景是更好地了解一种基本的运输机制，该机制决定了一些蛋白质如何从心脏（即心肌细胞）到达收缩细胞的表面。为了实现这一目标，我们首先建议通过对小鼠进行基因操作来研究去除一种名为 Arf6 的蛋白质（其他细胞中蛋白质运输的重要调节因子）如何影响心脏功能。将进一步分析受 Arf6 去除影响的细胞表面蛋白，以确定 Arf6 如何影响这些蛋白的定位和/或降解，以及它如何影响它们在心肌细胞膜上的功能。此外，我们将研究 Arf6 在心脏源性外泌体的生成和释放中的作用，外泌体是心肌细胞在被其他细胞摄取之前在其直接环境和全身循环中释放的小囊泡。值得注意的是，我们将分别使用无偏蛋白质组分析和 miRNA 筛选来确定 Arf6 的缺失如何影响心肌细胞释放的外泌体数量，以及它们的蛋白质和 miRNA 含量。令人惊讶的是，虽然这种细胞间保守的通讯系统在过去几年中引起了人们的兴趣，但这些外泌体产生所涉及的机制尚未完全了解。因此，我们期望我们的发现将加深我们对心脏内体和外泌体运输的了解，这是心肌细胞生物学中一个基本但仍然神秘的细胞过程。该研究项目的发现将为多个个人和团体带来好处。首先，我实验室培养的高素质人才（HQP）将受益于激励性的研究环境。这些 HQP 将成为心脏生物学、分子信号传导、基因操作和相关最先进技术（如小鼠模型超声心动图评估）方面的专家，以解决心脏研究领域最紧迫的挑战。此外，考虑到人们对基础心血管研究的兴趣日益浓厚，以及该研究项目的新颖之处，我们相信我们的发现将产生可转置的知识，从而引导其他研究小组在各自的专业领域提出假设和发现。