Center of Bio & Micro/Nano Functional Materials, State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, PR China.
Institute of Fluorescent Probes for Biological Imaging, School of Chemistry and Chemical Engineering, School of Biological Science and Technology, University of Jinan, Jinan, 250022, PR China.
Biomaterials. 2017 Mar;120:46-56. doi: 10.1016/j.biomaterials.2016.12.016. Epub 2016 Dec 22.
Liquid-ordered (Lo) and liquid-disordered (Ld) microdomains in plasma membrane play different yet essential roles in various bioactivities. However, discrimination of the two microdomains in living cells is difficult, due to the similarity in their constituents and structures. Up to now, polarity sensitive probes are the only tool for imaging the two microdomains, but their small difference between emission spectra in the two microdomains (less than 50 nm) limited their application in living cells. In this work, we first presented an aggregation/monomer type of fluorescent probe (2,7-9E-BHVC12) with much larger separation in emission wavelength (up to 100 nm), for dual-color visualizing the two membrane microdomains in living cells. The probe can form red-emissive aggregates and yellow-emissive monomers when induced by Lo and Ld microdomains, respectively, and thus enables clear visualization of the two membrane microdomains in living cells with dual colors, and thus high-fidelity images of substructures of plasma membrane have been obtained. According to the images of three kinds of normal cells and three kinds of cancer cells stained with 2,7-9E-BHVC12, significant difference in plasma membrane microstructure of cancer cells was found. In terms of 2,7-9E-BHVC12, normal cells were mainly consisted of either Lo or Ld microdomains all over their membranes, while cancer cells all clearly display coexistence of Lo and Ld membrane microdomains. Therefore, 2,7-9E-BHVC12 can serve as a powerful tool for studies of membrane microdomains, and the different results of normal and cancer cells would also deepen our understanding in cancer science.
在质膜中，液态有序（Lo）和液态无序（Ld）微区在各种生物活性中发挥着不同但同样重要的作用。然而，由于它们的组成和结构相似，因此在活细胞中区分这两种微区是很困难的。到目前为止，极性敏感探针是成像这两种微区的唯一工具，但其在两个微区之间的发射光谱差异较小（小于 50nm），限制了其在活细胞中的应用。在这项工作中，我们首次提出了一种聚集/单体型荧光探针（2,7-9E-BHVC12），其发射波长的分离更大（高达 100nm），用于在活细胞中双颜色可视化两种膜微区。探针可以分别在 Lo 和 Ld 微区诱导下形成红色发射聚集物和黄色发射单体，从而可以用双颜色清晰地可视化活细胞中的两种膜微区，并获得质膜亚结构的高保真图像。根据用 2,7-9E-BHVC12 染色的三种正常细胞和三种癌细胞的图像，发现癌细胞的质膜微观结构存在显著差异。对于 2,7-9E-BHVC12，正常细胞的膜上主要由 Lo 或 Ld 微区组成，而癌细胞则明显显示 Lo 和 Ld 膜微区共存。因此，2,7-9E-BHVC12 可以作为研究膜微区的有力工具，正常细胞和癌细胞的不同结果也将加深我们对癌症科学的理解。
