Proteins involved in the organizing of lipid rafts can be found in exosomes, as shown for caveolin‐1, and they could contribute to exosomal cargo sorting, as shown for flotillins. Stomatin belongs to the same stomatin/prohibitin/flotillin/HflK/C family of lipid rafts proteins, but it has never been studied in exosomes except for extracellular vesicles (EVs) originating from blood cells. Here we first show the presence of stomatin in exosomes produced by epithelial cancer cells (non–small cell lung cancer, breast, and ovarian cancer cells) as well as in EVs from biological fluids, including blood plasma, ascitic fluids, and uterine flushings. A high abundance of stomatin in EVs of various origins and its enrichment in exosomes make stomatin a promising exosomal marker. Comparison with other lipid raft proteins and exosomal markers showed that the level of stomatin protein in exosomes from different sources corresponds well to that of CD9, while it differs essentially from flotillin‐1 and flotillin‐2 homologs, which in turn are present in exosomes in nearly equal proportions. In contrast, the level of vesicular caveolin‐1 as well as its EV‐to‐cellular ratio vary drastically depending on cell type.

中文翻译：

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胃抑素在不同来源的外泌体中高表达，并且有望作为外泌体标记。

如小窝蛋白-1所示，可在脂质体中发现与脂质筏组织有关的蛋白质，如弗洛蒂林所示，它们可有助于脂质体的货物分选。Stomatin属于脂筏蛋白的同一个Stomatin / Prohibitin / Flotillin / HflK / C家族，但除来自血细胞的细胞外囊泡（EV）外，从未在外泌体中进行过研究。在这里，我们首先显示在由上皮癌细胞（非小细胞肺癌，乳腺癌和卵巢癌细胞）产生的外泌体中以及在由血浆，腹水和子宫冲洗液等生物体液产生的电动汽车中是否存在抑菌素。各种来源的电动汽车中大量的抑菌素及其在外泌体中的富集使抑菌素成为有希望的外泌体标志物。与其他脂质筏蛋白和外泌体标记物的比较表明，来自不同来源的外泌体中的抑胃素蛋白水平与CD9相当，而它本质上不同于flotillin-1和flotillin-2同源物，后者又存在于外泌体中。几乎相等的比例。相比之下，根据细胞类型的不同，水泡小窝蛋白1的水平及其EV与细胞的比率也有很大差异。