Data Sheet 1_Composition of cardiac-derived extracellular vesicles changes with vesicle origin and determines uptake.pdf

IntroductionCardiovascular disease (CVD) is a leading cause of mortality worldwide. The potency of cell-based therapies for CVD is increasingly attributed to the release of small extracellular vesicles (sEVs) which consist of a lipid/protein membrane and encapsulate nucleic cargo. Specifically, sEVs from ckit + progenitor cells (CPCs) and mesenchymal stromal cells (MSCs) are shown to be pro-reparative, with clinical trials conducted. Despite copious research into sEV cargo, the role of parent cell type on sEV membrane composition and its effects on sEV uptake mechanism by recipient cells remain unclear. This is crucial for designing sEV-based therapeutics as uptake mechanism dictates the functionality of the cargo.
MethodsIn this study we investigate the role of sEV parent cell and membrane composition on the mechanism of EV uptake by recipient cells.
ResultsWe find that sEV membrane lipid and protein composition varies by parent cell type. Further, vesicle uptake mechanism varies by both sEV parent cell type and recipient cell type, with clathrin-mediated uptake being the most variable across parent cell conditions. Using a partial least squares regression model, we observe that proteins important in clathrin-mediated uptake (e.g., TPM1, MRC2, FSTL1, LTBP1) are dissimilar to other vesicle uptake mechanisms.
DiscussionThis work underscores the importance of the sEV source and membrane composition on uptake, and in turn the importance of selecting specific sEVs based on the target recipient cells for CVD therapies.

引言 心血管疾病（Cardiovascular disease, CVD）是全球范围内的首要致死病因。细胞治疗在心血管疾病中的治疗潜力，日益被归因于小型细胞外囊泡（small extracellular vesicles, sEVs）的释放——这类囊泡由脂质/蛋白质膜构成，并包裹核酸载荷。具体而言，来自ckit+祖细胞（ckit+ progenitor cells, CPCs）与间充质基质细胞（mesenchymal stromal cells, MSCs）的sEVs已被证实具有促修复作用，相关临床试验已相继开展。尽管针对sEV载荷的研究已较为丰富，但亲本细胞类型对sEV膜组分的影响，以及其对受体细胞摄取sEV机制的作用仍不明确。这一点对于开发基于sEV的治疗手段至关重要，因为摄取机制直接决定了载荷的功能发挥。
方法 本研究旨在探究sEV的亲本细胞类型与膜组分，对受体细胞摄取细胞外囊泡（extracellular vesicles, EVs）机制的影响。
结果 本研究发现，sEV的膜脂质与蛋白质组成因亲本细胞类型而异。进一步研究表明，囊泡的摄取机制同时取决于sEV亲本细胞类型与受体细胞类型，其中网格蛋白介导的摄取途径在不同亲本细胞条件下差异最为显著。通过偏最小二乘回归（partial least squares regression）模型分析，我们观察到与网格蛋白介导摄取相关的蛋白质（如TPM1、MRC2、FSTL1、LTBP1）与其他囊泡摄取机制相关蛋白存在显著差异。
讨论 本研究凸显了sEV来源与膜组分对摄取过程的重要性，进而表明在心血管疾病治疗中，需根据目标受体细胞类型选择适配的sEVs。