Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, Department of Chemistry, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200241, China.
College of Material, Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology, Ministry of Education, Hangzhou Normal University, Hangzhou 311121, Zhejiang, China.
Anal Chem. 2022 Aug 2;94(30):10813-10823. doi: 10.1021/acs.analchem.2c01714. Epub 2022 Jul 24.
Calcium and chloride levels are closely related to lysosome dysfunction. However, the simultaneous measurement of calcium (Ca) and chloride (Cl) in acidic subcellular organelles, which is conducive to a deep understanding of lysosome-related biological events, remains a challenge. In this study, we developed a pH-insensitive, ratiometric NIR nanoprobe for the simultaneous detection of Ca and Cl in acidic lysosomes and determined the roles of the two ions in lysosome function. The upconversion nanoprobe with blue, green, and red emissions was modified with a Ca-sensitive dye (Rhod-5N) and Cl-responsive fluorophore (10,10'-bis[3-carboxypropyl]-9,9'-biacridinium dinitrate, BAC). As a result of a dual-luminescence resonance energy transfer between upconversion nanoparticles (UCNPs) and Rhod-5N/BAC, the blue and green upconversion luminescence (UCL) of UCNPs were quenched and the red UCL was used as the reference signal. The ratiometric upconversion nanoprobe possesses a specific ability for the concurrent recognition of Ca and Cl ions independent of the influence of the environmental pH. To locate the probe in the lysosome, dextran was further modified with upconversion nanoparticles. Then, the nanoprobe with a high spatial resolution was constructed for the simultaneous monitoring of Ca and Cl in acidic lysosomes. Moreover, it was found that the reduction of lysosomal Cl affects the release of lysosomal Ca, which further blocks the activities of specific lysosomal enzymes. The ratiometric NIR nanoprobe has great potential for decoding and evaluating lysosomal diseases.
钙和氯离子水平与溶酶体功能障碍密切相关。然而，在酸性亚细胞细胞器中同时测量钙（Ca）和氯（Cl），有助于深入了解与溶酶体相关的生物学事件，但这仍然是一个挑战。在本研究中，我们开发了一种对 pH 不敏感的比率型近红外纳米探针，用于在酸性溶酶体中同时检测 Ca 和 Cl，并确定了这两种离子在溶酶体功能中的作用。该上转换纳米探针具有蓝色、绿色和红色发射，并用 Ca 敏感染料（Rhod-5N）和 Cl 响应荧光团（10,10'-双[3-羧丙基]-9,9'-双吖啶二硝酸盐，BAC）进行了修饰。由于上转换纳米颗粒（UCNPs）和 Rhod-5N/BAC 之间的双荧光共振能量转移，UCNPs 的蓝色和绿色上转换发光（UCL）被猝灭，而红色 UCL 被用作参考信号。比率型上转换纳米探针具有独立于环境 pH 影响的同时识别 Ca 和 Cl 离子的特定能力。为了将探针定位在溶酶体中，进一步用葡聚糖对其进行修饰。然后，构建了具有高空间分辨率的纳米探针，用于同时监测酸性溶酶体中的 Ca 和 Cl。此外，研究发现溶酶体 Cl 的减少会影响溶酶体 Ca 的释放，从而进一步阻断特定溶酶体酶的活性。该比率型近红外纳米探针在解码和评估溶酶体疾病方面具有巨大的潜力。
