Novel long-wavelength emissive lysosome-targeting ratiometric fluorescent probes for imaging in live cells
Novel long-wavelength emissive lysosome-targeting ratiometric fluorescent probes for imaging in live cells
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用于活细胞成像的新型长波长发射溶酶体比率荧光探针
DOI：
10.1039/c9an00697d
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发表时间：
2019
期刊：
影响因子：
4.2
通讯作者：
Shuang Shaomin
中科院分区：
文献类型：
--
作者：
Ge Jinyin;Zhang Kai;Fan Li;Wang Xiaodong;Zhang Caihong;Dong Chuan;Wong Man Shing;Shuang Shaomin
溶酶体是酸性细胞器，含有许多负责降解大分子的水解酶。已知异常的溶酶体pH变化与溶酶体功能障碍相关，溶酶体功能障碍与包括癌症和神经退行性疾病在内的各种疾病相关。因此，监测溶酶体pH变化以研究病理状况是至关重要的。我们在此报告了两种新型的，高灵敏度和快速响应的咔唑为基础的比率荧光探针，具有不同的发射波长，即MCDBI和MCDI的溶酶体pH值检测和成像。重要的是，带有吲哚和苯并吲哚作为酸敏感位点的MCDBI和MCDI探针分别表现出4.26和4.51的pKa值，这对于活细胞中溶酶体pH变化的定量分析是理想的。这些探针表现出强烈的pH依赖性行为，并线性和快速响应轻微的pH波动。此外，这两种生物相容性探针具有高度的溶酶体靶向性，对H+的敏感性超过金属离子和一些生物活性分子，并具有良好的光稳定性和可逆性。这些探针具有良好的细胞膜渗透性，并进一步成功地应用于监测溶酶体的pH值波动的HepG2细胞的溶酶体。
Lysosomes are acidic organelles containing many hydrolytic enzymes responsible for degrading macromolecules. Aberrant lysosomal pH changes are known to associate with lysosomal dysfunctions linking to various diseases including cancer and neurodegenerative disorders. Thus, it is of paramount importance to monitor lysosomal pH changes in order to investigate the pathological conditions. We report herein two novel, highly sensitive and fast responsive carbazole-based ratiometric fluorescent probes with different emission wavelengths, namely MCDBI and MCDI for lysosomal pH detection and imaging. Importantly, the MCDBI and MCDI probes bearing indole and benzoindoles as acid-sensing sites exhibit pKa values of 4.26 and 4.51, respectively, which are ideal for the quantitative analysis of lysosomal pH changes in living cells. These probes exhibited a strong pH-dependent behavior and responded linearly and rapidly to minor pH fluctuations. Moreover, the two biocompatible probes are highly lysosomal targeting, sensitive towards H+ over metal ions and some bioactive molecules, and exhibit excellent photostability and good reversibility. These probes have excellent cell membrane permeability and are further applied successfully to monitor lysosomal pH fluctuations in the lysosomes of HepG2 cells.