Scavenger receptor-recognized and enzyme-responsive nanoprobe for fluorescent labeling of lysosomes in live cells
Scavenger receptor-recognized and enzyme-responsive nanoprobe for fluorescent labeling of lysosomes in live cells
复制标题
用于活细胞中溶酶体荧光标记的清道夫受体识别和酶响应纳米探针
DOI：
10.1016/j.biomaterials.2014.05.054
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发表时间：
2014
期刊：
影响因子：
14
通讯作者：
Daoyong Chen
中科院分区：
文献类型：
--
作者：
Yanbin Fan;Fuyou Li;Daoyong Chen
溶酶体成像是通过诊断和治疗方法研究相关细胞事件的组织及其调节的有力工具。然而，对活细胞中的溶酶体进行特异性标记是一个重大的挑战。利用纳米颗粒固有的溶酶体进入和溶酶体中独特的消化包裹体，我们开发了一种基于纳米颗粒的、酶可切换的荧光关闭策略，用于特定标记溶酶体，并进一步成像细胞外酸化诱导的溶酶体在活细胞中的运输。该纳米探针由一个16 nm的球形金纳米粒子为核心，以荧光素偶联寡聚(4-乙烯基苯基磷酸)的酶反应低聚物为外壳。由于核心金纳米颗粒的猝灭，纳米探针是非荧光的。在与癌细胞孵育后，纳米探针通过清道夫受体介导的内吞作用被迅速内化，并显著地洗牌进入溶酶体。由于溶酶体诱导的荧光增强，纳米探针特异性地照亮了溶酶体。具体地说，溶酶体中的消化包涵体水解并释放金猝灭的荧光素分子，导致荧光显著增强。由于特定的溶酶体标记，当酸性细胞外环境形成时，纳米探针有效地促进了溶酶体从核周区到细胞表面的4-6μm顺行转运事件的成像。我们的发现共同强调了纳米探针在溶酶体成像中的应用。
Lysosomal imaging represents a potent tool for investigating the organization of related cellular events and their modulationviadiagnostic and therapeutic approaches. However, specific labeling of the lysosome in live cells is a significant challenge. Taking advantage of the inherent lysosomal entry of nanoparticles and unique digestive inclusions in the lysosome, we developed a nanoparticle-based, enzyme-switchable fluorescence OFF-ON strategy for specific labeling of the lysosome and further imaging of extracellular acidification-induced lysosome trafficking in living cells. The nanoprobe comprised a 16 nm spherical gold nanoparticle as the core and an enzyme-responsive oligomer of fluorescein-conjugated oligo(4-vinyl-phenyl phosphate) as the shell. Due to quenching of the core gold nanoparticle, the nanoprobe was non-fluorescent. After incubation with cancer cells, the nanoprobe was rapidly internalizedviascavenger receptor-mediated endocytosis and significantly shuffled into the lysosome. The nanoprobe specifically lighted up the lysosome owing to lysosome-induced fluorescence enhancement. Specifically, digestive inclusions in the lysosome hydrolyzed and released gold-quenched fluorescein molecules, leading to significant augmentation of fluorescence. On account of specific lysosomal labeling, the nanoprobe effectively facilitated imaging of a 4–6 μm anterograde trafficking event of the lysosome from the perinuclear region to the cell surface when an acidic extracellular environment developed. Our findings collectively highlight the use of nanoprobes for lysosomal imaging.