Department of Mechanical Engineering, University of Kentucky, Lexington, KY, 40506, USA.
Department of Chemistry, University of Kentucky, Lexington, KY, 40506, USA.
Anal Bioanal Chem. 2024 Nov;416(28):6317-6331. doi: 10.1007/s00216-024-05518-z. Epub 2024 Sep 7.
Studying specific subpopulations of cancer-derived extracellular vesicles (EVs) could help reveal their role in cancer progression. In cancer, an increase in reactive oxygen species (ROS) happens which results in lipid peroxidation with a major product of 4-hydroxynonenal (HNE). Adduction by HNE causes alteration to the structure of proteins, leading to loss of function. Blebbing of EVs carrying these HNE-adducted proteins as a cargo or carrying HNE-adducted on EV membrane are methods for clearing these molecules by the cells. We have referred to these EVs as Redox EVs. Here, we utilize a surface tension-mediated extraction process, termed exclusion-based sample preparation (ESP), for the rapid and efficient isolation of intact Redox EVs, from a mixed population of EVs derived from human glioblastoma cell line LN18. After optimizing different parameters, two populations of EVs were analyzed, those isolated from the sample (Redox EVs) and those remaining in the original sample (Remaining EVs). Electron microscopic imaging was used to confirm the presence of HNE adducts on the outer leaflet of Redox EVs. Moreover, the population of HNE-adducted Redox EVs shows significantly different characteristics to those of Remaining EVs including smaller size EVs and a more negative zeta potential EVs. We further treated glioblastoma cells (LN18), radiation-resistant glioblastoma cells (RR-LN18), and normal human astrocytes (NHA) with both Remaining and Redox EV populations. Our results indicate that Redox EVs promote the growth of glioblastoma cells, likely through the production of HO, and cause injury to normal astrocytes. In contrast, Remaining EVs have minimal impact on the viability of both glioblastoma cells and NHA cells. Thus, isolating a subpopulation of EVs employing ESP-based immunoaffinity could pave the way for a deeper mechanistic understanding of how subtypes of EVs, such as those containing HNE-adducted proteins, induce biological changes in the cells that take up these EVs.
研究癌症来源的细胞外囊泡 (EV) 的特定亚群有助于揭示它们在癌症进展中的作用。在癌症中,活性氧 (ROS) 增加,导致脂质过氧化,主要产物是 4-羟基壬烯醛 (HNE)。HNE 的加合物导致蛋白质结构改变,导致功能丧失。携带这些 HNE 加合物作为货物的 EV 泡状突起或携带 EV 膜上 HNE 加合物的 EV 是细胞清除这些分子的方法。我们将这些 EV 称为氧化还原 EV。在这里,我们利用一种表面张力介导的提取过程,称为基于排除的样品制备 (ESP),从人胶质母细胞瘤细胞系 LN18 衍生的 EV 混合物中快速有效地分离完整的氧化还原 EV。在优化了不同参数后,分析了两种 EV 群体,一种是从样品中分离出来的(氧化还原 EV),另一种是留在原始样品中的(剩余 EV)。电子显微镜成像用于确认氧化还原 EV 外叶上 HNE 加合物的存在。此外,与剩余 EV 相比,HNE 加合物氧化还原 EV 的群体表现出明显不同的特征,包括更小的 EV 大小和更负的 EV zeta 电位。我们进一步用剩余和氧化还原 EV 群体处理胶质母细胞瘤细胞 (LN18)、辐射抗性胶质母细胞瘤细胞 (RR-LN18) 和正常人类星形胶质细胞 (NHA)。我们的结果表明,氧化还原 EV 促进胶质母细胞瘤细胞的生长,可能是通过产生 HO 并导致正常星形胶质细胞损伤。相比之下,剩余 EV 对胶质母细胞瘤细胞和 NHA 细胞的活力几乎没有影响。因此,采用基于 ESP 的免疫亲和分离 EV 的亚群可以为深入了解 EV 亚群(如含有 HNE 加合物的蛋白质)如何诱导摄取这些 EV 的细胞发生生物学变化提供途径。