Inducible macropinocytosis of hyaluronan in B16-F10 melanoma cells
Inducible macropinocytosis of hyaluronan in B16-F10 melanoma cells
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DOI：
10.1016/j.matbio.2010.06.004
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发表时间：
2010-07-01
期刊：
影响因子：
6.9
通讯作者：
Mummert, Mark E.
中科院分区：
文献类型：
--
作者：
Greyner, Henry J.;Wiraszka, Tomasz;Mummert, Mark E.
透明质酸（HA）是由N-乙酰葡糖胺和葡萄糖醛酸亚基组成的糖胺聚糖。由于HA降解透明质酸酶的细胞内区室化，内吞作用被认为在HA的催化中起重要作用。先前的研究表明，角质形成细胞、软骨细胞和乳腺肿瘤细胞系通过细胞表面糖蛋白CD 44内吞HA。然而，其他类型的细胞内吞HA使用的CD 44-非依赖性机制，仍有待确定。本研究的目的是研究HA在B16-F10黑素瘤细胞中的内吞作用。我们发现B16-F10黑色素瘤细胞在其表面表达CD 44。出乎意料的是，CD 44在HA的内吞作用中不起作用。电子显微镜研究表明，B16-F10黑色素瘤细胞表现出膜抽滤，巨胞饮的特征，只有在孵育的HA共聚物的细胞。此外，B16-F10黑色素瘤细胞通过巨胞饮作用内吞HA，如通过药物抑制研究和共聚焦显微镜下荧光标记HA与荧光示踪剂的共定位所评估的。基于这些结果，我们得出结论，诱导的巨胞饮作用可能提供了一个以前未被认识的途径，在某些细胞类型的HA内吞作用。(C)2010 Elsevier B. V.保留所有权利。
Hyaluronan (HA) is a glycosaminoglycan composed of N-acetylglucosamine and glucuronic acid subunits. Endocytosis is thought to play an essential role in the catabolism of HA due to the intracellular compartmentalization of the HA degrading hyaluronidase enzymes. Previous investigations have shown that keratinocytes, chondrocytes and breast tumor cell lines endocytose HA via the cell surface glycoprotein, CD44. However, other cell types endocytose HA using a CD44-independent mechanism that remains to be defined. The purpose of this study was to investigate HA endocytosis in B16-F10 melanoma cells. We found that B16-F10 melanoma cells expressed CD44 on their surfaces. Unexpectedly, CD44 did not play a role in the endocytosis of HA. Electron microscopy studies revealed that B16-F10 melanoma cells exhibited membrane raffling, a characteristic feature of macropinocytosis, only after incubating the cells with the HA co-polymer. Moreover, B16-F10 melanoma cells endocytosed HA via macropinocytosis as assessed by drug inhibition studies and the co-localization of fluorescently labeled HA with fluorescent tracers under confocal microscopy. Based on these results, we conclude that induced macropinocytosis may provide a previously unrecognized avenue for HA endocytosis in some cell types. (C) 2010 Elsevier B.V. All rights reserved.