Page Michael J, Lourenço André L, David Tovo, LeBeau Aaron M, Cattaruzza Fiore, Castro Helena C, VanBrocklin Henry F, Coughlin Shaun R, Craik Charles S
Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94158-2517, USA.
CAPES Foundation, Ministry of Education of Brazil, Brasília DF 70040-020, Brazil.
Nat Commun. 2015 Oct 1;6:8448. doi: 10.1038/ncomms9448.
Functional imaging of proteolytic activity is an emerging strategy to quantify disease and response to therapy at the molecular level. We present a new peptide-based imaging probe technology that advances these goals by exploiting enzymatic activity to deposit probes labelled with near-infrared (NIR) fluorophores or radioisotopes in cell membranes of disease-associated proteolysis. This strategy allows for non-invasive detection of protease activity in vivo and ex vivo by tracking deposited probes in tissues. We demonstrate non-invasive detection of thrombin generation in a murine model of pulmonary embolism using our protease-activated peptide probes in microscopic clots within the lungs with NIR fluorescence optical imaging and positron-emission tomography. Thrombin activity is imaged deep in tissue and tracked predominantly to platelets within the lumen of blood vessels. The modular design of our probes allows for facile investigation of other proteases, and their contributions to disease by tailoring the protease activation and cell-binding elements.
蛋白水解活性的功能成像作为一种新兴策略，可在分子水平对疾病和治疗反应进行量化。我们提出了一种基于肽的新型成像探针技术，该技术通过利用酶活性将标记有近红外（NIR）荧光团或放射性同位素的探针沉积在疾病相关蛋白水解的细胞膜中，从而推进了这些目标的实现。这种策略通过追踪组织中沉积的探针，实现了体内和体外蛋白酶活性的无创检测。我们利用蛋白酶激活肽探针，通过近红外荧光光学成像和正电子发射断层扫描，在肺栓塞小鼠模型的肺部微小凝块中，证明了对凝血酶生成的无创检测。凝血酶活性在组织深处成像，并且主要追踪到血管腔内的血小板。我们探针的模块化设计允许通过定制蛋白酶激活和细胞结合元件，方便地研究其他蛋白酶及其对疾病的作用。
