Fluorescence-topographic NSOM directly visualizes peak-valley polarities of GM1/GM3 rafts in cell membrane fluctuations
Fluorescence-topographic NSOM directly visualizes peak-valley polarities of GM1/GM3 rafts in cell membrane fluctuations
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DOI：
10.1194/jlr.d800031-jlr200
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发表时间：
2008-10-01
影响因子：
6.5
通讯作者：
Chen, Zheng W.
中科院分区：
文献类型：
--
作者：
Chen, Yong;Qin, Jie;Chen, Zheng W.
在膜超微结构的背景下，细胞表面分子的同时荧光拓扑纳米级成像还没有报道。在这里，基于近场扫描光学显微镜（NSOM）的直接荧光地形成像表明，GM 3筏/纳米结构域（190.0 +/-49.8 nm，范围84.5-365.0 nm）主要位于GM 31 Madin-Darby犬肾细胞顶膜中微绒毛样突起的峰上，而GM 1筏/纳米结构域（159.5 +/-63.8nm，范围42-360 nm）主要分布在GM 1 + MDCK细胞质膜中突起的斜坡或突起之间的谷上。这些数据表明，神经节苷脂极化不仅在一个众所周知的顶底侧的方式，但也在更微观的峰谷的方式，暗示独特的分布GM 1或GM 3极化细胞的顶膜上的细胞表面波动。神经节苷脂的峰谷极性也暗示了它们与脂筏、微绒毛或细胞过程相关的不同功能。重要的是，我们的研究第一次证明了基于NSOM的直接荧光地形成像是独特的和强大的，用于阐明特定细胞表面分子在膜波动中的纳米级分布。
Simultaneous fluorescence-topographic nanoscale imaging of cell-surface molecules in the context of membrane ultra-structures has not been reported. Here, near-field scanning optical microscopy (NSOM)-based direct fluorescence-topographic imaging indicated that GM3 rafts/nanodomains (190.0 +/- 49.8 nm ranging 84.5-365.0 nm) were localized predominantly on the peaks of microvillus-like protrusions in the apical membrane of GM3 1 Madin-Darby canine kidney cells, whereas GM1 rafts/nanodomains (159.5 +/- 63.8 nm ranging 42-360 nm) were distributed mainly on the slops of protrusions or the valleys between protrusions in the plasma membranes of GM1 + MDCK cells. The data demonstrated that gangliosides polarized not only in a well-known apical-basolateral manner but also in the more microscopic peak-valley manner, implicating unique distribution of GM1 or GM3 in cell-surface fluctuations on the apical membrane of polarized cells. The peak-valley polarities of gangliosides also implicated their different functions relevant to lipid rafts, microvilli, or cellular processes. Importantly, our study demonstrated for the first time that the NSOM-based direct fluorescence-topographic imaging is unique and powerful for elucidating nanoscale distribution of specific cell-surface molecules in membrane fluctuations.