Ultrastructural study of echinocytes induced by poly (ethylene glycol)-cholesterol
Ultrastructural study of echinocytes induced by poly (ethylene glycol)-cholesterol
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DOI：
10.1007/s00418-004-0723-8
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发表时间：
2004-12-01
影响因子：
2.3
通讯作者：
Sato, SB
中科院分区：
文献类型：
--
作者：
Baba, T;Terada, N;Sato, SB
聚（乙二醇）-胆固醇（PEG-Chol）由亲水性PEG和疏水性胆固醇部分组成。当PEG-Chol应用于红细胞时，试剂通过仅分布在膜的外单层中定量诱导突起。这种反应被认为是一种降低外单分子层膨胀应力的一般反应。然而，膜结构和这些分子的分布之间的关系是未知的。在这项研究中，我们检查了标记的PEG-胆固醇沿着的形状变化途径的分布。棘细胞形状是由盘状体边缘最初形成的突起开始的，随后突起延长为突起。这些突起包含颗粒状结构的聚集体，其似乎适应外部单层面积的增加。在较高浓度下，PEG-胆固醇进一步诱导球形棘红细胞增多，导致许多分支突起过程。我们发现，PEG-胆固醇是专门分布在这些突起，特别是，积累在尖端。这些结果表明，外部嵌入的PEG-Chol作为膜突起通过未知的机制从红细胞中螯合。
Poly (ethylene glycol)-cholesterol (PEG-Chol) consists of a hydrophilic PEG and hydrophobic cholesterol moiety. When PEG-Chol was applied to erythrocytes, the reagent quantitatively induced protrusions by exclusively distributing in the outer monolayer of the membrane. This kind of response has been regarded as a general response that reduces the stress of expansion of the outer monolayer. However, the relationship between the membrane architecture and the distribution of such molecules is unknown. In this study, we examined the distribution of tagged PEG-Chol along the shape change pathway. The echinocytic shape was initiated by the initial formation of bumps on the rim of the discoid, which subsequently elongated as protrusions. These protrusions contained aggregates of granular structures, which appeared to accommodate the increase in the outer monolayer area. At higher concentrations, PEG-Chol further induced sphero-echinocytosis that resulted in numerous branched protrusion processes. We found that PEG-Chol was exclusively distributed in these protrusions and, in particular, accumulated at the tips. These results suggested that externally intercalated PEG-Chol was sequestrated from erythrocytes as membrane protrusions through an as-yet-unknown mechanism.