细胞膜定位锌离子荧光和磷光探针用于跟踪锌离子从胰岛β细胞释放的动态过程

Zn2+ ions in Pancreatic β cells are coordinated with insulin and co-released with insulin on stimulation. This phenomenon has been exploited to develop experiments using Zn2+ fluorescent probes as a surrogate for measuring the dynamic process of insulin release. This would greatly advance our understanding of diabetes mellitus. However, the reported fluorescent probes for Zn2+ are difficult to meet the requirements including specific binding selectivity and accurate localization. In this project, we will introduce our reported receptor ZTRS, which shows extremely selectivity for zinc, to construct new ratiometric fluorescent and phosphorescent probes. These probes would localize specifically to the plasma membrane using SNAP-tag technology. It is helpful to track the dynamic process of zinc release from pancreatic βcells using fluorescence imaging and phosphorescence lifetime imaging technologies,thus indicates the dynamic insulin release process.

锌离子从胰岛细胞释放与胰岛素的释放密切相关。通过跟踪锌离子释放到胞外的动态过程能够揭示胰岛素的释放，有助于理解糖尿病的发病机理。已报道的细胞膜定位锌离子荧光探针缺乏对锌离子的专一选择性和对细胞膜的精确定位。本项目基于本课题组前期报道的专一锌离子选择性受体ZTRS构建荧光和磷光探针，利用SNAP蛋白标签技术将探针精确定位于细胞膜外，通过荧光成像和磷光寿命成像多种技术，精确跟踪锌离子从胰岛β细胞释放的动态过程，从而指示胰岛素的动态释放过程。

跟踪胰岛素向胰岛β细胞外的释放有助于研究胰岛β细胞的分泌功能和探讨糖尿病的发病机理。然而能够原位标记胰岛素并跟踪其动态释放过程的探针还未见报道。已有研究表明：胰岛β细胞向细胞外释放胰岛素的同时，原来与胰岛素配位的锌离子也成为自由锌离子而被释放到细胞外。因此，通过跟踪锌离子释放到胞外的过程能够帮助揭示胰岛素向胰岛细胞外释放的过程。本项目创制一系列新型细胞膜定位的锌离子荧光，通过荧光成像技术，精确跟踪锌离子跨膜的动态过程，从而帮助研究胰岛素的释放过程。