Pang Cui, Song Chaojun, Li Yize, Wang Qiaofeng, Zhu Xiaosheng, Wu Jianwei, Tian Yi, Fan Hao, Hu Jinwei, Li Chen, Wang Baolong, Li Xiaoye, Liu Wenchao, Fan Li
Department of Oncology, Xijing Hospital, Air Force Medical University, Xi'an, 710032, Shaanxi, China.
School of Life Science, Northwestern Polytechnic University, 127th Youyi West Road, Xi'an, 710072, Shaanxi, China.
Nanoscale Res Lett. 2020 Jul 8;15(1):143. doi: 10.1186/s11671-020-03367-0.
Acidic pH of lysosomes is closely related to autophagy; thus, well known of the precise lysosomes, pH changes will give more information on the autophagy process and status. So far, however, only pH changes in a relatively broad range could be indicated, the exact lysosomes pH detection has never arrived. In our study, we established an endo/lysosome pH indicator based on the self-decomposable SiO nanoparticle system with specific synthesis parameters. The central concentrated methylene blue (MB) in the central-hollow structural nanoparticles presented sensitive release as a function of pH values from pH 4.0-4.8, which is exactly the pH range of lysosomes. The linear correlation of the optical density (OD) values and the pH values has been built up, which has been used for the detection of lysosomes pH in 6 different cell lines. Moreover, by this system, we succeeded in precisely detecting the pH average changes of lysosomes before and after black mesoporous silicon (BPSi) NP endocytosis, clarifying the mechanism of the autophagy termination after BPSi endocytosis. So, the self-decomposable nanoparticle-based luminal pH indicator may provide a new methodology and strategy to know better of the lysosome pH, then indicate more details on the autophagy process or other important signaling about metabolisms.
溶酶体的酸性pH与自噬密切相关；因此，鉴于溶酶体pH变化的确切情况已为人熟知，其变化将提供更多关于自噬过程和状态的信息。然而，到目前为止，只能检测到相对较宽范围内的pH变化，从未实现对溶酶体pH的确切检测。在我们的研究中，我们基于具有特定合成参数的可自分解SiO纳米颗粒系统建立了一种内体/溶酶体pH指示剂。中心中空结构纳米颗粒中的中心浓缩亚甲蓝（MB）随着pH值在4.0 - 4.8之间变化呈现出灵敏的释放，而这正是溶酶体的pH范围。已建立光密度（OD）值与pH值之间的线性相关性，并用于检测6种不同细胞系中的溶酶体pH。此外，通过该系统，我们成功精确检测了黑色介孔硅（BPSi）纳米颗粒内吞前后溶酶体的平均pH变化，阐明了BPSi内吞后自噬终止的机制。所以，基于可自分解纳米颗粒的腔内pH指示剂可能为更好地了解溶酶体pH提供一种新的方法和策略，进而揭示自噬过程或其他重要代谢信号的更多细节。
