Format

Send to

Choose Destination
FASEB J. 2014 Jan;28(1):464-73. doi: 10.1096/fj.13-234229. Epub 2013 Oct 10.

Intracellular gene transcription factor protein-guided MRI by DNA aptamers in vivo.

Author information

1
3Massachusetts General Hospital, CNY149 (2301) Thirteenth St., Charlestown, MA 02129, USA. philipl@nmr.mgh.harvard.edu.

Abstract

The mechanisms by which transcription factor (TF) protein AP-1 modulates amphetamine's effects on gene transcription in living brains are unclear. We describe here the first part of our studies to investigate these mechanisms, specifically, our efforts to develop and validate aptamers containing the binding sequence of TF AP-1 (5ECdsAP1), in order to elucidate its mechanism of action in living brains. This AP-1-targeting aptamer, as well as a random sequence aptamer with no target (5ECdsRan) as a control, was partially phosphorothioate modified and tagged with superparamagnetic iron oxide nanoparticles (SPIONs), gold, or fluorescein isothiothianate contrast agent for imaging. Optical and transmission electron microscopy studies revealed that 5ECdsAP1 is taken up by endocytosis and is localized in the neuronal endoplasmic reticulum. The results of magnetic resonance imaging (MRI) with SPION-5ECdsAP1 revealed that neuronal AP-1 TF protein levels were elevated in neurons of live male C57black6 mice after amphetamine exposure; however, pretreatment with SCH23390, a dopaminergic receptor antagonist, suppressed this elevation. As studies in transgenic mice with neuronal dominant-negative A-FOS mutant protein, which has no binding affinity for the AP-1 sequence, showed a completely null MRI signal in the striatum, we can conclude that the MR signal reflects specific binding between the 5ECdsAP1 aptamer and endogenous AP-1 protein. Together, these data lend support to the application of 5ECdsAP1 aptamer for intracellular protein-guided imaging and modulation of gene transcription, which will thus allow investigation of the mechanisms of signal transduction in living brains.

KEYWORDS:

AP1 knockout; attention; monoamine oxidase A; stress; transgenic mice

PMID:
24115049
PMCID:
PMC3868842
DOI:
10.1096/fj.13-234229
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Atypon Icon for PubMed Central
Loading ...
Support Center