Freie Universität Berlin, Institute of Pharmacy, Pharmaceutical Biology, Dahlem Center of Plant Sciences, Königin-Luise-Str. 2+4, D-14195 Berlin, Germany.
Luxembourg Institute of Science and Technology, Environmental Research and Innovation Department, 5 rue Bommel, L-4940 Hautcharage, Luxembourg.
Int J Mol Sci. 2021 Apr 2;22(7):3719. doi: 10.3390/ijms22073719.
While human extracellular vesicles (EVs) have attracted a big deal of interest and have been extensively characterized over the last years, plant-derived EVs and nanovesicles have earned less attention and have remained poorly investigated. Although a series of investigations already revealed promising beneficial health effects and drug delivery properties, adequate (pre)clinical studies are rare. This fact might be caused by a lack of sources with appropriate qualities. Our study introduces plant cell suspension culture as a new and well controllable source for plant EVs. Plant cells, cultured in vitro, release EVs into the growth medium which could be harvested for pharmaceutical applications. In this investigation we characterized EVs and nanovesicles from distinct sources. Our findings regarding secondary metabolites indicate that these might not be packaged into EVs in an active manner but enriched in the membrane when lipophilic enough, since apparently lipophilic compounds were associated with nanovesicles while more hydrophilic structures were not consistently found. In addition, protein identification revealed a possible explanation for the mechanism of EV cell wall passage in plants, since cell wall hydrolases like 1,3--glucosidases, pectinesterases, polygalacturonases, -galactosidases and -xylosidase/-L-arabinofuranosidase 2-like are present in plant EVs and nanovesicles which might facilitate cell wall transition. Further on, the identified proteins indicate that plant cells secrete EVs using similar mechanisms as animal cells to release exosomes and microvesicles.
虽然人类细胞外囊泡 (EVs) 在过去几年中引起了广泛关注，并得到了广泛的研究，但植物来源的 EVs 和纳米囊泡却受到较少关注，研究也较少。尽管一系列研究已经揭示了其具有有前景的有益健康的作用和药物传递特性，但充分的（临床前）研究仍然很少。造成这种情况的原因可能是缺乏具有适当质量的来源。我们的研究介绍了植物细胞悬浮培养作为植物 EVs 的一种新的、可很好控制的来源。在体外培养的植物细胞会将 EVs 释放到生长培养基中，可以从中收获用于药物应用。在本研究中，我们对不同来源的 EVs 和纳米囊泡进行了表征。我们关于次生代谢物的发现表明，这些物质可能不会以活跃的方式被包装到 EVs 中，而是在足够亲脂时富集在膜中，因为显然亲脂性化合物与纳米囊泡相关，而更亲水的结构则不一致。此外，蛋白质鉴定为植物 EV 穿过细胞壁的机制提供了一个可能的解释，因为细胞壁水解酶，如 1,3-β-葡糖苷酶、果胶酯酶、多聚半乳糖醛酸酶、β-半乳糖苷酶和β-木糖苷酶/ L-阿拉伯呋喃糖苷酶 2 样酶，存在于植物 EVs 和纳米囊泡中，这可能有助于细胞壁的转变。此外，鉴定出的蛋白质表明，植物细胞通过类似于动物细胞释放外泌体和微泡的类似机制来分泌 EVs。
