Growth media conditions influence the secretion route and release levels of engineered extracellular vesicles

Extracellular vesicles (EVs) are nanosized cell-derived vesicles found in all bodily fluids which provide a route of intercellular communication by transmitting biological cargo. While EVs offer promise as therapeutic agents, the molecular mechanisms of EV biogenesis are not yet fully elucidated, in part due to the concurrence of numerous interwoven pathways which give rise to heterogenous EV populations in vitro. The effects of conditions in the cellular environment on EV production are of particular interest. In this study, we utilize a quantifiable EV-engineering approach to investigate how various cell media conditions alter EV production. The presence of serum, exogenous EVs, and other signaling factors in cell media alters EV production on physical, molecular, and transcriptional levels. Further, we demonstrate that exosome biogenesis pathways are the major factors contributing to EV production under optimized conditions. Our findings suggest a novel understanding to the mechanisms underlying EV production in cell culture which can be applied to develop advanced EV production methods. Sequencing of HEK293 cells in different media conditions

细胞外囊泡（Extracellular vesicles，EVs）是一类源自细胞的纳米级囊泡，广泛分布于所有体液中，通过传递生物载荷介导细胞间通讯。尽管EVs作为治疗剂展现出巨大应用潜力，但其生物发生的分子机制尚未完全阐明，部分原因在于体外培养体系中存在大量相互交织的通路，共同产生了异质性的EV群体。细胞微环境条件对EV生成的影响尤其受到研究者关注。本研究采用可量化的EV工程化策略，探究不同细胞培养基条件如何改变EV的生成水平。细胞培养基中血清、外源性EVs及其他信号因子的存在，会从物理、分子及转录层面影响EV的生成。此外，本研究证实，在优化培养条件下，外泌体生物发生通路是影响EV生成的核心因素。本研究结果为阐明细胞培养体系中EV生成的潜在机制提供了全新视角，可用于开发更先进的EV生产方法。本研究对不同培养基条件下的HEK293细胞开展了测序分析。