Monitoring Autophagy with Atg4B Protease-Activated Aggregation-Induced Emission Probe
Monitoring Autophagy with Atg4B Protease-Activated Aggregation-Induced Emission Probe
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DOI：
10.1002/adfm.202108571
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发表时间：
2021-10-27
影响因子：
19
通讯作者：
Zhu, Wei-Hong
中科院分区：
文献类型：
--
作者：
Lyu, Yanting;Chen, Xiaoyan;Zhu, Wei-Hong
自噬对于身体发育和疾病发病机制至关重要。自噬监测仍然受到非实时性和特异性差的限制。在此，作者报告了 Atg4B 酶作为自噬生物标志物的研究，以及 Atg4B 响应性聚集诱导发射 (AIE) 探针（称为 QM-GFTN）的开发。特别是，GFTN的掺入肽单元具有良好的分散性，但当亲水性肽被Atg4B切割时，状态可以逆转，从而实现具有高信噪比（S/N）的发光荧光。该探针对Atg4B表现出优异的选择性，能够响应其在溶液和活细胞中的活性，从而有效地区分自噬活性和自噬非活性状态，与传统方法相比大大缩短了检测时间。细胞荧光成像和自噬抑制剂研究表明QM-GFTN被Atg4B特异性切割，排除了其自聚集的可能性。通过将Atg4B可裂解肽接枝到AIE荧光团上，基于肽的探针可以在保证高特异性的情况下对Atg4B活性进行实时可视化，为检测各种自噬细胞、动物组织甚至人类病理组织中的自噬过程提供了重大突破。
Autophagy is crucial in the physical development and pathogenesis of disease. Monitoring autophagy is still limited by no real-time and poor specificity. Herein, the authors report studies of Atg4B enzyme as a biomarker for autophagy and the development of an Atg4B-responsive aggregation-induced emission (AIE) probe, termed QM-GFTN. Particularly, the incorporated peptide unit of GFTN endows good dispersion, but the state can be reversed when the hydrophilic peptide is cleaved by the Atg4B, thus realizing a light-up fluorescence with high signal/noise (S/N) ratio. The probe exhibits excellent selectivity to Atg4B, and can respond to its activity in solution and living cells, thus efficiently distinguishing autophagy-active from autophagy-inactive states, greatly shortening the detection time comparing to the traditional methods. The fluorescence imaging of cells and autophagy-inhibitor studies indicate that QM-GFTN is specifically cleaved by Atg4B, and rules out the possibility of its self-aggregation. By grafting Atg4B-cleavable peptide to AIE fluorophore, the peptide-based probe can carry out real-time visualization of Atg4B activity with guaranteeing high specificity, serving as a great breakthrough to the detection of autophagy process in various autophagic cells, animal tissues, and even human pathological tissues.