A Mirror Image Fluorogenic Aptamer Sensor for Live-Cell Imaging of MicroRNAs

Area of Science:

• Biochemistry
• Molecular Biology
• Oligonucleotide Chemistry

Background:

• Developing biocompatible tools for intracellular RNA imaging is challenging.
• Existing methods often struggle with stability and functionality in biological environments.

Purpose of the Study:

• To create novel, biocompatible miRNA sensors for live-cell imaging.
• To demonstrate the utility of l-RNA aptamers for intracellular RNA detection.

Main Methods:

• Utilized heterochiral strand-displacement to link endogenous d-miRNAs with l-RNA Mango III aptamer.
• Designed a sensor where target d-RNA displaces a blocking strand, activating fluorescence.
• Employed a self-delivering l-Mango sensor for in vivo imaging.

Main Results:

• Developed a new class of biocompatible miRNA sensors based on l-RNA Mango III aptamer.
• Demonstrated sensor functionality in serum, unlike d-Mango counterparts.
• Successfully imaged microRNA-155 expression in living cells using the l-Mango sensor.

Conclusions:

• This work presents a new paradigm for developing biocompatible, hybridization-based RNA sensors.
• Expanded the application of fluorogenic aptamers for live-cell RNA imaging.
• Achieved the first successful interface of l-oligonucleotides with living systems for RNA detection.