State Key Laboratory of Crystal Materials, and Advanced Medical Research Institute, Shandong University, Jinan 250100, People's Republic of China.
Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering, Feringa Nobel Prize Scientist Joint Research Center, East China University of Science & Technology, Shanghai 200237, People's Republic of China.
J Am Chem Soc. 2021 Mar 3;143(8):3169-3179. doi: 10.1021/jacs.0c12323. Epub 2021 Feb 11.
In living systems, subcellular organelles mutually cooperate and closely contact to form organelle interaction networks. Thus, the simultaneous and discriminative visualization of different organelles is extremely valuable for elucidating their distribution and interplay. However, such meaningful investigations remain a great challenge due to the lack of advanced single fluorescent probes (SF-probes) capable of simultaneous and two-color imaging of two targets. Herein, for the first time, we present two excited-state intramolecular proton transfer (ESIPT) based SF-probes (PPC and EPC) for simultaneous two-color fluorescence imaging of lipid droplets (LDs) and the endoplasmic reticulum (ER) under single-wavelength excitation. Due to the strong electron-donating ability of the side substituents, the fluorescence spectra and colors of these ESIPT probes are highly sensitive to the nuance of water contents between LDs and ER, leading to orange and green fluorescence in LDs and ER, respectively, in the Lambda imaging mode. Using the probe PPC or EPC, the morphology, size, and distribution of LDs and ER have been investigated in live cells and tissues. With the aid of and real-time fluorescence imaging in Lambda mode, we observed the generation of newborn LDs near the ER regions and their close apposition and shared identical fluorescence colors, probably providing a valuable proof for the mainstream hypothesis that LDs originate from the ER. The remarkable imaging performances render these SF-probes as powerful tools to decipher LD-ER related biological processes.
在生命系统中，亚细胞细胞器相互合作并紧密接触，形成细胞器相互作用网络。因此，同时且有区别地可视化不同的细胞器对于阐明它们的分布和相互作用非常有价值。然而，由于缺乏能够同时对两个靶标进行双色成像的先进单荧光探针（SF-probes），因此进行此类有意义的研究仍然是一个巨大的挑战。在此，我们首次提出了两种基于激发态分子内质子转移（ESIPT）的 SF-probes（PPC 和 EPC），用于在单波长激发下同时对脂滴（LDs）和内质网（ER）进行双色荧光成像。由于侧基具有很强的给电子能力，这些 ESIPT 探针的荧光光谱和颜色对 LDs 和 ER 之间水含量的细微差别非常敏感，导致在 Lambda 成像模式下 LDs 和 ER 分别发出橙色和绿色荧光。使用探针 PPC 或 EPC，我们在活细胞和组织中研究了 LDs 和 ER 的形态、大小和分布。借助和实时荧光成像在 Lambda 模式下，我们观察到新生 LDs 在 ER 区域附近生成，它们紧密贴合且具有相同的荧光颜色，这可能为 LDs 起源于 ER 的主流假说提供了有价值的证据。这些 SF-probes 的显著成像性能使其成为破译 LD-ER 相关生物学过程的有力工具。
