The Key Laboratory of Life-Organic Analysis; Key Laboratory of Pharmaceutical Intermediates and Analysis of Natural Medicine, College of Chemistry and Chemical Engineering , Qufu Normal University , Qufu 273165 , P. R. China.
College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Institute of Molecular and Nano Science , Shandong Normal University , Jinan 250014 , P. R. China.
Anal Chem. 2018 Nov 6;90(21):12442-12448. doi: 10.1021/acs.analchem.8b01505. Epub 2018 Oct 17.
Organisms have built up immunological systems, where mitochondrial SO plays conflicting roles in regulating cell apoptosis. However, no exploration on the influence and regulating principle of mitochondrial SO to the specific apoptosis type can be found, which brings about a challenge to fluorescent probes. Herein, we optimize the fluorophore and develop a new fluorescent probe FHMI (( E)-4-(3-formyl-4-hydroxystyryl)-1-methylpyridin-1-iumiodide) by equipping an ICT (intramolecular charge transfer) fluorophore HMII (( E)-4-(4-hydroxystyryl)-1-methylpyridin-1-ium iodide) with an aldehyde group that serves as both fluorescence quencher and reporting group. After the optimization, although the nonconjugated electron donor is formed when sensing SO, the preset ICT fluorophore HMII is permitted to release the fluorescence at the enlarged wavelength. Compared with the traditional design, the probe FHMI exhibits obvious enhanced fluorescence with large red shift. FHMI is successfully applied to the mechanistic exploration of the dichotomous effects of mitochondrial SO to cells apoptosis, showing that mitochondrial SO regulates the early apoptosis of HeLa cells via the reduction of mitochondrial membrane potential. FHMI is applied to explore the dichotomous bioinfluence of mitochondrial SO to HeLa cells under oxidative stress, visualizing the regulative role of mitochondrial SO in the apoptotic process. For the first time, the mitochondrial SO is visually found to be closely associated with the early apoptosis of HeLa cells. Moreover, FHMI proves to be readily applicable to monitoring endogenous SO in zebrafish. This probe can act as an effective optical tool for exploring SO in biospecimen.
生物体建立了免疫系统，其中线粒体 SO 在调节细胞凋亡方面起着相互矛盾的作用。然而，目前还没有发现关于线粒体 SO 对特定凋亡类型的影响和调节原理的探索，这给荧光探针带来了挑战。在这里，我们通过在 ICT（分子内电荷转移）荧光团 HMII（（E）-4-（4-羟基苯乙烯基）-1-甲基吡啶鎓碘化物）上配备一个醛基，将荧光团 HMII （（E）-4-（4-羟基苯乙烯基）-1-甲基吡啶鎓碘化物）优化为一个新的荧光探针 FHMI（（E）-4-（3-甲酰基-4-羟基苯乙烯基）-1-甲基吡啶鎓碘化物），该醛基既可以作为荧光猝灭剂，也可以作为报告基团。经过优化，虽然在检测 SO 时形成了非共轭电子供体，但预设的 ICT 荧光团 HMII 被允许在扩大的波长处释放荧光。与传统设计相比，探针 FHMI 表现出明显增强的荧光和较大的红移。FHMI 成功应用于线粒体 SO 对细胞凋亡的二分效应的机制探索，表明线粒体 SO 通过降低线粒体膜电位来调节 HeLa 细胞的早期凋亡。FHMI 被应用于在氧化应激下探索线粒体 SO 对 HeLa 细胞的二分生物影响，可视化了线粒体 SO 在凋亡过程中的调节作用。首次发现线粒体 SO 与 HeLa 细胞的早期凋亡密切相关。此外，FHMI 被证明易于应用于监测斑马鱼内源性 SO。该探针可以作为探索生物样本中 SO 的有效光学工具。
