双光子荧光成像脑组织中半胱天蛋白酶活性

项目名称： 双光子荧光成像脑组织中半胱天蛋白酶活性

项目编号： No.61505076

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 无线电电子学、电信技术

项目作者： 李林

作者单位： 南京工业大学

项目金额： 20万元

中文摘要： 半胱天蛋白酶（Caspases）是介导细胞凋亡的重要蛋白质，参与细胞凋亡、发育、坏死、炎症等许多重要的生理过程。在蛋白酶的家族中，半胱天蛋白酶的活性高低对细胞来说具有两面性；较低的半胱天蛋白酶活性可能会导致肿瘤发生，而过高的半胱天蛋白酶活性又可能促进神经退行性病变。目前，半胱天蛋白酶活性的研究大多停留在细胞水平上，主要是由于缺乏有效地研究组织和生物体内Caspases活性的化学/生物探针。本项目拟结合Caspases与多肽荧光底物发生反应释放荧光信号的设计原理，以2-乙酰基-6-氨基萘和4-氨基-1,8-萘二甲酰亚胺为双光子荧光团，连接于不同Caspases的多肽底物中天冬氨酸残基的羧基基团，合成可用于神经细胞（细胞凋亡模型）/脑组织（小鼠脑损伤模型）中Caspases生物活性检测的双光子荧光小分子探针底物，用于双光子荧光成像分析神经细胞/脑组织中Caspases的生物活性。

中文关键词： 基于酶活性的荧光探针；双光子荧光成像；生物组织成像；多肽分子探针；有机荧光染料

英文摘要： Cysteinyl aspartate specific protease (Caspases) play an essential role in cell apoptosis, as well as many important physiology processes such as cell growth, necrosis and inflammation. Amongst the various types of proteases, caspases work as a double-edged sword, depending upon their activation levels, to up/down-regulate protein activities. Defective caspases may result in tumorigenesis, and on the contrary, extreme caspases activation can promote neurodegeneration. At present, dynamic studies of caspases activation have mostly remained at the cellular level, largely due to a lack in cell permeable imaging probes capable of direct, realtime investigations of caspases activities in deep tissues. In this project, we aim to synthesis two-photon fluorescent small-molecule enzymatic probes by using 2-acetyl-6-aminonaphthalene and 4-aminonaphthalimide as two-photon fluorophores, whose photophysical properties will be changed after coupling aspartic acid. The newly synthesized reaction-based caspases peptide probes can real-time image individual caspases (-1, -3, -6, -7, -8 and -9) activities in live neuron cells (apoptosis model) and brain tissue (ethanol-intoxicated mice model) under physiological conditions by using two-photon fluorescence microscopy.

英文关键词： Enzymatic probe;Two-photon fluorescence imaging;Tissue imaging;Peptide based probe;Organic fluorescent dye