Ramos Corinne, Bonato David, Winterhalter Mathias, Stegmann Toon, Teissié Justin
Institut de Pharmacologie et de Biologie Structurale du CNRS, UMR 5089, 205, route de Narbonne, 31077 Cedex 4, Toulouse, France.
FEBS Lett. 2002 May 8;518(1-3):135-8. doi: 10.1016/s0014-5793(02)02676-5.
Fusion is obtained between electropermeabilized mammalian cells and intact large unilamellar lipid vesicles. This is monitored by a fluorescence assay. Prepulse contact is obtained by Ca2+ when negatively charged lipids are present in the liposomes. The mixing of the liposome content in the cell cytoplasm is observed under conditions preserving cell viability. Electric conditions are such that free liposomes are not affected by the external field. Therefore destabilization of only one of the two membranes of the partners is sufficient for fusion. The comparison between the efficiency of dye delivery for different liposome preparations (multilamellar vesicles, large unilamellar vesicles, small unilamellar vesicles) is indicative that more metastable liposomes are more fusable with electropulsated cells. This observation is discussed within the framework of the recent hypothesis that occurrence of a contact induced electrostatic destabilization of the plasma membrane is a key step in the exocytosis process.
电穿孔处理的哺乳动物细胞与完整的大单层脂质体之间实现了融合。这通过荧光测定法进行监测。当脂质体中存在带负电荷的脂质时，预脉冲接触通过Ca2+实现。在保持细胞活力的条件下观察脂质体内容物在细胞质中的混合情况。电条件使得游离脂质体不受外部电场影响。因此，仅使融合伙伴的两个膜之一不稳定就足以实现融合。不同脂质体制剂（多层囊泡、大单层囊泡、小单层囊泡）的染料递送效率比较表明，更亚稳的脂质体与电脉冲处理的细胞更易融合。在最近的假说框架内讨论了这一观察结果，该假说认为质膜接触诱导的静电不稳定的发生是胞吐过程中的关键步骤。
