Cellular uptake and subsequent intracellular trafficking of R8-liposomes introduced at low temperature
Cellular uptake and subsequent intracellular trafficking of R8-liposomes introduced at low temperature
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DOI：
10.1016/j.bbamem.2006.04.015
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发表时间：
2006-06-01
影响因子：
3.4
通讯作者：
Harashima, Hideyoshi
中科院分区：
文献类型：
--
作者：
Iwasa, Akitada;Akita, Hidetaka;Harashima, Hideyoshi
细胞内转运是基因载体转基因表达效率的决定因素。在本研究中，研究了在37℃和4℃下引入的八精氨酸(R8)修饰脂质体在活细胞中的细胞摄取机制。与37℃相比，R8-脂质体的摄取仅在4℃时略有下降，脂质体和质膜的双重成像显示，R8-脂质体在37℃时通过囊泡转运内化，并部分逃逸到核周区域的胞浆中。当4℃时，在靠近质膜的特定区域内观察到细胞内脂质体，质膜的内化完全被抑制。因此，在4℃时，R8脂质体似乎通过独特的途径进入细胞，这与能量依赖的囊泡运输是分开的和不同的。随后在4℃下引入的包裹的PDNA的核传递与37℃引入的相比没有那么显著。总之，这些发现表明，囊泡运输独立的途径负责细胞对脂质体的摄取。此外，摄取途径与随后的核递送过程密切相关；内源性囊泡分选系统的运行有利于PDNA的核递送。(C)2006爱思唯尔B.V.保留所有权利。
Intracellular trafficking is a determining factor in the transgene expression efficiency of gene vectors. In the present study, the mechanism of the cellular uptake of octaarginine (R8)-modified liposomes, when introduced at 37 degrees C and 4 degrees C, was investigated in living cells. Compared with 37 degrees C, the uptake of R8-liposomes was only slightly reduced at 4 degrees C. Dual imaging of liposomes and plasma membranes revealed that R8-liposomes were internalized by vesicular transport, and partially escaped to the cytosol at the perinuclear region at 37 degrees C. When introduced at 4 degrees C, intracellular liposomes were observed within a specific region close to the plasma membrane, and internalization of the plasma membrane was completely inhibited. Therefore, at 4 degrees C, R8-liposomes appear to enter cells via unique pathway, which is separate and distinct from energy-dependent vesicular transport. The subsequent nuclear delivery of encapsulated pDNA, when introduced at 4 degrees C, was less prominent compared with those introduced at 37 degrees C. Collectively, these findings demonstrate that a vesicular transport-independent pathway is responsible for the cellular uptake of liposomes. In addition, the uptake route is closely related to the subsequent nuclear delivery process; the operation of an endogenous vesicular sorting system is advantageous for the nuclear delivery of pDNA. (c) 2006 Elsevier B.V All rights reserved.