Identification and characterization of cell-bound membrane vesicles
Identification and characterization of cell-bound membrane vesicles
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细胞结合膜囊泡的鉴定和表征
DOI：
10.1016/j.bbamem.2017.01.013
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发表时间：
2017-05-01
影响因子：
3.4
通讯作者：
Chen, Yong
中科院分区：
文献类型：
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作者：
Tang, Qisheng;Zhang, Xiaojun;Chen, Yong
与释放/循环的膜囊泡（细胞外囊泡）相比，细胞结合的膜囊泡的鉴定和表征较差。在这项研究中，细胞结合膜囊泡在人脐静脉内皮细胞（HUVECs）和人肝癌细胞HepG-2进行了研究。我们发现，细胞结合膜囊泡与细胞外囊泡的主要标志物（例如磷脂酰丝氨酸、CD 63、CD 107 α、CD 31和三种已知类型的细胞外囊泡的DNA片段）和具有相似大小的细胞内细胞器（例如线粒体和多泡体或溶酶体的MitoTracker和LAMP 1/LAMP 3）不共定位。这些数据表明，细胞结合膜囊泡既不是细胞外囊泡的前体，也不是由细胞内细胞器推高的假结构，但可能是质膜中的一种新的未知结构。此外，我们发现，细胞结合的膜囊泡是耐各种洗涤剂，包括但可能不限于Triton X-100，SDS，和皂苷。我们进一步表征了这些独特的囊泡可溶于有机溶剂（例如氯仿-甲醇混合物和乙醇），这可以通过脂质稳定固定剂（例如OsO 4）来防止，并且它们与脂筏（质膜中的纳米尺寸的洗涤剂抗性域）的主要标志物（例如小窝蛋白-1和GM 1）共定位，但不独占。这些数据表明，细胞结合的膜囊泡含有脂质成分和脂筏。其他具体的未知成分的参与可能解释洗涤剂的细胞结合膜囊泡的阻力。进一步的研究将主要取决于建立一种有效的方法，用于分离/纯化这些囊泡从质膜。(C)2017爱思唯尔B. V.保留所有权利。
In contrast to the released/circulating membrane vesicles (extracellular vesicles), cell-bound membrane vesicles are poorly identified and characterized. In this study, cell-bound membrane vesicles on human umbilical vein endothelial cells (HUVECs) and human hepatoma HepG-2 cells were investigated. We identified that cell-bound membrane vesicles are not co-localized with the major markers for extracellular vesicles (e.g. phosphatidylserine, CD63, CD107 alpha, CD31, and DNA fragments for the three well-known types of extracellular vesicles) and for intracellular organelles with similar sizes (e.g. MitoTracker and LAMP1/LAMP3 for mitochondria and multivesicular bodies or lysosomes, respectively). The data imply that cell-bound membrane vesicles are neither the precursors of extracellular vesicles nor a false structure pushed up by an intracellular organelle but probably a novel unknown structure in the plasma membrane. Moreover, we revealed that cell-bound membrane vesicles are resistant to various detergents including but probably not limited to Triton X-100, SDS, and saponin. We further characterized that these unique vesicles are soluble in organic solvents (e.g. chloroform-methanol mixture and ethanol) which can be prevented by a lipid-stabilizing fixative (e.g. OsO4) and that they are co-localized with, but do not monopolize, the major markers (e.g. caveolin-1 and GM1) for lipid rafts (a nano-sized detergent-resistant domains in the plasma membrane). The data imply that cell-bound membrane vesicles contain the lipid component and lipid rafts. Involvement of other specific unknown components might explain the detergent resistance of cell-bound membrane vesicles. Further research will mainly depend on the establishment of an effective approach for isolation/purification of these vesicles from the plasma membrane. (C) 2017 Elsevier B.V. All rights reserved.