School of Chemistry and Chemical Engineering, School of Materials Science and Engineering, University of Jinan, Jinan, Shandong 250022, P. R. China.
J Mater Chem B. 2022 Jul 6;10(26):4999-5007. doi: 10.1039/d2tb00580h.
Lysosomes, as the main degradative organelles, play an important role in a variety of cellular metabolic activities including autophagy and apoptosis, catabolism and transporting substances. Lysosomal autophagy is an important physiological process and causes a slight change in the intra-lysosomal pH to facilitate the breakdown of macromolecular proteins. Therefore, detecting the fluctuation of intra-lysosomal pH is of great significance in monitoring physiological and pathological activities in living organisms. However, few probes have enabled the ratiometric monitoring of lysosomal pH and lysosomal autophagy in dual channels. Fortunately, spiropyrans, as compounds with multistimuli-responsive discoloration properties, form two different isomers under acid induction and ultraviolet induction. To fill this gap, in this work, two novel multistimuli-responsive fluorescent probes with lysosomal targeting in dual channels based on spiropyrans were rationally designed and synthesized. Notably, the two probes exhibited different absorption wavelengths in their UV-responsive and pH-responsive moieties due to their different electron-donating groups. Moreover, bioimaging experiments clearly demonstrate that the probes Lyso-SP and Lyso-SQ monitor lysosomal autophagy by facilitating the visualization of fluctuations in intra-lysosomal pH. Meanwhile, their potential applications in the field of dual-anticounterfeiting were explored based on their photoluminescence ability. We expect that more multistimuli-responsive fluorescent probes can be developed by this design approach.
溶酶体作为主要的降解细胞器，在包括自噬和细胞凋亡、分解代谢和物质运输在内的各种细胞代谢活动中发挥着重要作用。溶酶体自噬是一种重要的生理过程，会导致溶酶体内 pH 值发生轻微变化，从而促进大分子蛋白质的分解。因此，检测溶酶体内 pH 值的波动对于监测生物体内的生理和病理活动具有重要意义。然而，很少有探针能够实现溶酶体 pH 值和溶酶体自噬的双通道比色监测。幸运的是，螺吡喃作为一种具有多刺激响应变色特性的化合物，在酸诱导和紫外光诱导下形成两种不同的异构体。为了填补这一空白，在这项工作中，我们基于螺吡喃设计并合成了两种具有双通道溶酶体靶向的新型多刺激响应荧光探针。值得注意的是，由于供电子基团的不同，这两个探针在其对紫外光和 pH 值响应的部分表现出不同的吸收波长。此外，生物成像实验清楚地表明，探针 Lyso-SP 和 Lyso-SQ 通过促进溶酶体内 pH 值波动的可视化来监测溶酶体自噬。同时，还基于其发光能力探索了它们在双重防伪领域的潜在应用。我们期望通过这种设计方法能够开发出更多的多刺激响应荧光探针。
