Wu Jun, Hu Qinyu, Chen Qing, Dai Jun, Wu Xia, Wang Shixuan, Lou Xiaoding, Xia Fan
Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430078, China.
Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
ACS Appl Bio Mater. 2020 Dec 21;3(12):9002-9011. doi: 10.1021/acsabm.0c01249. Epub 2020 Nov 11.
DNA adenine methylation (Dam) MTase serves a very important epigenetic process that transfers a methyl group on an adenine residue including -methyladenosine (mA). A variety of evidence have demonstrated that mA methylation plays a significant role in modulating genes in human disease and development. Hence, a modular DNA-incorporated AIEgen probe (TPE-Py-DNA) was specifically developed for detection and imaging of Dam MTase. TPE-Py-DNA consisted of two modules: a "turn-on" fluorescent AIEgen (TPE-Py) and a DNA sequence (Alk-DNA) involved in specific recognition of the targeted strand. The TPE-Py-DNA probe was dispersed and almost nonfluorescent in an aqueous environment. On the contrary, the TPE-Py-DNA molecule was digested based on the target-recycling strategy in assistance with exonuclease III (Exo III) when Dam MTase was presented, finally releasing aggregated AIEgens to produce a remarkably increased fluorescence signal. Therefore, the detection limit toward Dam MTase was as low as 3.1 × 10 U mL, and the fluorescent signal could be used to detect Dam MTase activities in real samples and screen its inhibitors. More importantly, the Dam MTase expression was visualized in cells via CLMS imaging and confirmed in cell-bearing tissues. In this vein, our results demonstrated that the TPE-Py-DNA probe is a potent tool for the Dam MTase detection and imaging as well as offers an efficient biosensing platform for further investigation of disease pathway and carcinogenesis.
DNA腺嘌呤甲基化（Dam）甲基转移酶参与一个非常重要的表观遗传过程，该过程会在包括N6-甲基腺苷（mA）的腺嘌呤残基上转移一个甲基。大量证据表明，mA甲基化在调节人类疾病和发育中的基因方面发挥着重要作用。因此，专门开发了一种模块化的DNA结合聚集诱导发光（AIE）探针（TPE-Py-DNA）用于Dam甲基转移酶的检测和成像。TPE-Py-DNA由两个模块组成：一个“开启”荧光AIE（TPE-Py）和一个参与靶向链特异性识别的DNA序列（Alk-DNA）。TPE-Py-DNA探针在水性环境中分散且几乎无荧光。相反，当存在Dam甲基转移酶时，TPE-Py-DNA分子在核酸外切酶III（Exo III）的协助下基于靶标循环策略被消化，最终释放聚集的AIE分子以产生显著增强的荧光信号。因此，对Dam甲基转移酶的检测限低至3.1×10^(-9) U mL，荧光信号可用于检测实际样品中Dam甲基转移酶的活性并筛选其抑制剂。更重要的是，通过共聚焦激光扫描显微镜（CLSM）成像在细胞中可视化了Dam甲基转移酶的表达，并在携带细胞的组织中得到证实。就此而言，我们的结果表明TPE-Py-DNA探针是用于Dam甲基转移酶检测和成像的有力工具，并为进一步研究疾病途径和致癌作用提供了一个高效的生物传感平台。
