Abstract

We used time-of-flight secondary ion mass spectrometry (ToF-SIMS) to study changes in the composition of the plasma membranes of human fetal fibroblasts under the action of nanosized anions of silicon molybdic acid. The dependences of the mass spectra of the main lipids of the plasma membranes on the silicon molybdate concentration were measured and interpreted; the dependences correlate with the layer-by-layer distributions and with the affinity of cholesterol for phospholipids. A new effect for cell biochemistry was discovered, that is, a significant decrease in the relative concentrations of cholesterol and sphingomyelin in plasma membranes under the effect of multiply charged heteropoly anions (HPAs). In aqueous silicon molybdate solutions with a concentration of c ≈ 10 µM/L and an exposure time of 48 h, the amount of cholesterol in plasma membranes decreased by 2–2.5 times, while the amount of sphingomyelin decreased by 20–25%. A new mechanism is proposed for the initial effect of HPA on plasma membranes, which consists of selective etching by multiply charged anions. According to the proposed mechanism, cholesterol and sphingomyelin, the main regulators of permeability and microviscosity of plasma membranes, are extracted from the plasma membrane at the first stage of the interaction of the polyoxometallate anion with the cell. As a consequence of the increased permeability of the plasma membranes in cells, acceleration of vital transmembrane and lateral processes may occur.

中文翻译：

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纳米钼酸硅阴离子对人胎儿成纤维细胞血浆膜的影响

摘要

我们使用飞行时间二次离子质谱（ToF-SIMS）研究了人类胎儿成纤维细胞的质膜组成在纳米硅钼酸阴离子作用下的变化。测量并解释了质膜主要脂质的质谱对钼酸硅浓度的依赖性。这种依赖性与层的分布以及胆固醇对磷脂的亲和力有关。发现了一种新的细胞生物化学作用，即在多电荷杂多阴离子（HPA）的作用下，质膜中胆固醇和鞘磷脂的相对浓度显着降低。在浓度为c的钼酸硅水溶液中≈10 µM / L，暴露时间为48 h，质膜中的胆固醇含量降低了2–2.5倍，而鞘磷脂的含量降低了20–25％。提出了一种新的机制来提高HPA对质膜的初始作用，该机制包括通过多电荷阴离子的选择性刻蚀。根据提出的机理，在多金属氧酸盐阴离子与细胞相互作用的第一阶段，从质膜中提取出质膜的通透性和微粘度的主要调节剂胆固醇和鞘磷脂。由于细胞中质膜的渗透性增加，可能会导致重要的跨膜和侧突的加速。