Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware, USA.
Delaware Biotechnology Institute, University of Delaware, Newark, Delaware, USA.
Biotechnol Bioeng. 2023 Sep;120(9):2700-2716. doi: 10.1002/bit.28356. Epub 2023 Mar 2.
A new area of focus in Chinese hamster ovary (CHO) biotechnology is the role of small (exosomes) and large (microvesicles or microparticles) extracellular vesicles (EVs). CHO cells in culture exchange large quantities of proteins and RNA through these EVs, yet the content and role of these EVs remain elusive. MicroRNAs (miRs or miRNA) are central to adaptive responses to stress and more broadly to changes in culture conditions. Given that EVs are highly enriched in miRs, and that EVs release large quantities of miRs both in vivo and in vitro, EVs and their miR content likely play an important role in adaptive responses. Here we report the miRNA landscape of CHO cells and their EVs under normal culture conditions and under ammonia and osmotic stress. We show that both cells and EVs are highly enriched in five miRs (among over 600 miRs) that make up about half of their total miR content, and that these highly enriched miRs differ significantly between normal and stress culture conditions. Notable is the high enrichment in miR-92a and miR-23a under normal culture conditions, in contrast to the high enrichment in let-7 family miRs (let-7c, let-7b, and let-7a) under both stress conditions. The latter suggests a preserved stress-responsive function of the let-7 miR family, one of the most highly preserved miR families across species, where among other functions, let-7 miRs regulate core oncogenes, which, depending on the biological context, may tip the balance between cell cycle arrest and apoptosis. While the expected-based on their profound enrichment-important role of these highly enriched miRs remains to be dissected, our data and analysis constitute an important resource for exploring the role of miRs in cell adaptation as well as for synthetic applications.
中国仓鼠卵巢（CHO）生物技术的一个新焦点是小（外泌体）和大（微泡或微粒）细胞外囊泡（EVs）的作用。培养中的 CHO 细胞通过这些 EVs 交换大量蛋白质和 RNA，但这些 EV 的内容和作用仍不清楚。MicroRNAs（miRs 或 miRNA）是对压力和更广泛的培养条件变化的适应性反应的核心。鉴于 EVs 高度富含 miRs，并且 EVs 在体内和体外大量释放 miRs，EVs 及其 miR 含量可能在适应性反应中发挥重要作用。在这里，我们报告了正常培养条件下以及氨和渗透胁迫下 CHO 细胞及其 EVs 的 miRNA 图谱。我们表明，细胞和 EVs 都高度富含 5 个 miR（在超过 600 个 miR 中），它们构成其总 miR 含量的约一半，并且这些高度富集的 miR 在正常和应激培养条件下差异显著。值得注意的是，miR-92a 和 miR-23a 在正常培养条件下高度富集，而在两种应激条件下，let-7 家族 miR（let-7c、let-7b 和 let-7a）高度富集。后者表明，let-7 miR 家族的应激反应功能得到了很好的保留，let-7 miR 家族是跨物种最保守的 miR 家族之一，在其他功能中，let-7 miRs 调节核心癌基因，这些基因根据生物学背景，可能会影响细胞周期停滞和细胞凋亡之间的平衡。虽然这些高度富集的 miR 基于其丰富程度预期具有重要作用，但仍有待剖析，但我们的数据和分析构成了探索 miR 在细胞适应中的作用以及合成应用的重要资源。
