期刊
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
卷 108, 期 31, 页码 12815-12820出版社
NATL ACAD SCIENCES
DOI: 10.1073/pnas.1109859108
关键词
-
资金
- National Institutes of Health (NIH) [P01 AI54904, U24 CA092782, R01 67536, R01 EB006432, 1RL9-EB-008539-01]
- Harvard Catalyst, the Harvard Clinical and Translational Science Center (NIH) [KL2 RR 025757]
- Harvard, Beth Israel Deaconess Medical Center
- German Academy of Sciences Leopoldina [LPDS 2009-24]
- [1-K99-DK-090210-01]
The hallmark of type 1 diabetes is autoimmune destruction of the insulin-producing beta-cells of the pancreatic islets. Autoimmune diabetes has been difficult to study or treat because it is not usually diagnosed until substantial beta-cell loss has already occurred. Imaging agents that permit noninvasive visualization of changes in beta-cell mass remain a high-priority goal. We report on the development and testing of a near-infrared fluorescent beta-cell imaging agent. Based on the amino acid sequence of exendin-4, we created a neopeptide via introduction of an unnatural amino acid at the K(12) position, which could subsequently be conjugated to fluorophores via bioorthogonal copper-catalyzed click-chemistry. Cell assays confirmed that the resulting fluorescent probe (E4(x12)-VT750) had a high binding affinity (similar to 3 nM). Its in vivo properties were evaluated using high-resolution intravital imaging, histology, whole-pancreas visualization, and endoscopic imaging. According to intravital microscopy, the probe rapidly bound to beta-cells and, as demonstrated by confocal microscopy, it was internalized. Histology of the whole pancreas showed a close correspondence between fluorescence and insulin staining, and there was an excellent correlation between imaging signals and beta-cell mass in mice treated with streptozotocin, a beta-cell toxin. Individual islets could also be visualized by endoscopic imaging. In short, E4(x12)-VT750 showed strong and selective binding to glucose-like peptide-1 receptors and permitted accurate measurement of beta-cell mass in both diabetic and nondiabetic mice. This near-infrared imaging probe, as well as future radioisotope-labeled versions of it, should prove to be important tools for monitoring diabetes, progression, and treatment in both experimental and clinical contexts.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据