Development of an Anti-Vascular Cell Adhesion Protein-1 Aptamer for Molecular Imaging and Inflammation Detection in Transgenic Mouse Model of Alzheimer's Disease

J Biomed Nanotechnol. 2015 Dec;11(12):2264-74. doi: 10.1166/jbn.2015.2154.

Abstract

Cerebrovascular inflammation is often involved in the pathogenesis of neurodegenerative disorders such as Alzheimer's disease (AD). Non-invasive and sensitive molecular imaging of cerebrovascular inflammation biomarkers therefore represents a potential AD diagnostic and therapeutic monitoring method. Here, we describe the development of a novel aptamer-based near infrared fluorescence imaging probe targeting Vascular Cell Adhesion Molecule-1 (VCAM-1), an adhesion molecule overexpressed by the activated cerebrovasculature during inflammation. A SELEX-type screening of a random ssDNA library against human VCAM-1 identified a high-affinity ssDNA aptamer with a dissociation constant of 49 nM. We demonstrated that the Cy5.5-labeled aptamer binds to activated endothelial cells, with no affinity to non-activated cells. A scrambled aptamer labeled with Cy5.5 did not image activated and non-activated endothelial cells, confirming the sequence specificity of the targeting. In vivo, the aptameric imaging agent targeting VCAM-1 successfully identified inflammation associated with amyloid-β plaques deposition in the vessels of the cerebellum of transgenic AD mice. It exhibited excellent retention by remaining bound to vessels 4 hours post-injection, indicating its effectiveness in in vivo imaging and its potential in early detection of cerebrovascular inflammation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alzheimer Disease / complications
  • Alzheimer Disease / diagnosis*
  • Animals
  • Aptamers, Nucleotide / genetics
  • Aptamers, Nucleotide / metabolism*
  • Base Sequence
  • Disease Models, Animal
  • Female
  • Human Umbilical Vein Endothelial Cells / metabolism
  • Humans
  • Inflammation / complications
  • Mice
  • Mice, Transgenic
  • Molecular Imaging / methods*
  • Optical Imaging
  • Vascular Cell Adhesion Molecule-1 / metabolism*

Substances

  • Aptamers, Nucleotide
  • Vascular Cell Adhesion Molecule-1