The effect of the size of fluorescent dextran on its endocytic pathway
The effect of the size of fluorescent dextran on its endocytic pathway
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DOI：
10.1002/cbin.10424
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发表时间：
2015-05-01
影响因子：
3.9
通讯作者：
Zhang, Rongying
中科院分区：
文献类型：
--
作者：
Li, Lei;Wan, Tao;Zhang, Rongying
荧光葡聚糖通常被用作巨胞饮细胞探针来研究内吞货物的性质;然而，葡聚糖的大小对内吞机制的影响尚未被仔细分析。通过使用单个内吞途径的化学和siRNA抑制，我们评估了两种常用的葡聚糖，Dex 10（葡聚糖10 kDa）和Dex 70（葡聚糖70 kDa）在哺乳动物HeLa细胞和秀丽隐杆线虫体腔细胞中的内化。我们发现，Dex 70进入这两种细胞类型主要是通过网格蛋白和动力蛋白独立和阿米洛利敏感的巨胞饮过程; Dex 10，另一方面，进入这两种细胞类型通过网格蛋白/动力蛋白依赖的微胞饮除了巨胞饮。此外，虽然不同大小的葡聚糖遵循不同的内吞过程，但它们具有共同的内吞后事件。在此，虽然简单明了，但我们的研究支持纳米材料的大小在其纳入内吞囊泡中可能起着至关重要的作用，并建议在选择内吞途径标记物时应小心。基于我们的研究结果，我们建议，Dex 70是一个更好的探针巨胞饮，而Dex 10和更小的分子是更好地探测一般的液相内吞，其中包括巨胞饮和微胞饮过程。
Fluorescent dextrans are commonly used as macropinocytic probes to study the properties of endocytic cargoes; however, the effect of the size of dextrans on endocytic mechanisms has not been carefully analyzed. By using chemical and siRNA inhibition of individual endocytic pathways, we evaluated the internalization of two commonly used dextrans, Dex10 (dextran 10kDa) and Dex70 (dextran 70kDa), in mammalian HeLa cells and Caenorhabditis elegans coelomocytes. We revealed that Dex70 enters these two cell types predominantly via clathrin- and dynamin-independent and amiloride-sensitive macropinocytosis process; Dex10, on the other hand, enters the two cell types through clathrin-/dynamin-dependent micropinocytosis in addition to macropinocytosis. In addition, although different-sized dextrans follow different endocytic processes, they share common post-endocytic events. Herein, though straightforward, our studies support that the size of nanomaterials could play a paramount role in their inclusion into endocytic vesicles and suggest that care should be taken while selecting endocytic pathway markers. Based on our results, we propose that Dex70 is a better probe for macropinocytosis, whereas Dex10 and smaller molecules are better for probing general fluid-phase endocytosis, which includes macropinocytic and micropinocytic processes.