RNA Aptamer Probes as Optical Imaging Agents for the Detection of Amyloid Plaques

• DOI: 10.1371/journal.pone.0089901
• Publication Date: 2014-02-26T22:17:15Z
• Authors: Christian T. Farrar; Christopher M. Wi...; Eloise Hudry; Tadafumi Hashimoto; Bradley T. Hyman
• Keywords: Aptamer; Fluorescence-lifetime imaging microscopy; Molecular Imaging; Amyloid (mycology); Molecular probe; Ex vivo

Optical imaging using multiphoton microscopy and whole body near infrared has become a routine part of biomedical research. However, optical methods rely on the availability either small molecule reporters or genetically encoded fluorescent proteins, which are challenging time consuming to develop. While directly labeled antibodies can also be used as agents, species specific, typically not tagged with multiple without interfering target binding, bioactive, almost always eliciting biological response thereby influencing process that is being studied. We examined possibility developing highly specific sensitive agents aptamer technology. developed fluorescently anti-Aβ RNA aptamer, β55, binds amyloid plaques in both ex vivo human Alzheimer's disease brain tissue APP/PS1 transgenic mice. Diffuse β55 positive halos, attributed oligomeric Aβ, were observed surrounding methoxy-XO4 plaque cores. Dot blots synthetic Aβ aggregates provide further evidence fibrillar non-fibrillar Aβ. The high binding affinity, ease probe development, ability incorporate multimodal suggest aptamers may have complementary perhaps advantageous properties compared conventional probes reporters.