Taking a glance at biological processes with DNA nanosensors
Nanomedicine is one of the latest branches of medicine that uses DNA nanotechnology, the artificial structure of nucleic acids. In the study entitled “Dissecting the intracellular signaling and fate of a DNA nanosensor by super-resolution and quantitative microscopy”, researchers from the Cardiovascular System – Mechanobiology (CSM) team of the International Clinical Research Center of St. Anne’s University Hospital Brno (FNUSA-ICRC) focused on the possibilitiy of observing protein localization using the latest DNA nanotechnology.
DNA-binding proteins are involved in several fundamental biological processes – such as apoptosis (programmed cell death), differentiation, cell survival or proliferation. Due to their fundamental role in the regulation of cellular processes, they are a promising target for drug development and cell therapy. There are already attempts to transfer DNA nanoparticles from in vitro to living cells, but we do not yet fully understand their functionality and behavior inside a living cell. “Current techniques for monitoring and quantifying DNA-binding proteins are multi-step, time-consuming and reagent-intensive, so a new approach to monitoring transcription factors (TF) directly in living cells would be very valuable,” said Fabiana Martino, CSM researcher.
In their study, the researchers used the most modern imaging methods of current microscopy. “We designed a DNA nanoswitch for the quantitative and qualitative detection of a DNA-binding protein called nuclear factor kappa B (NF-κB),” Fabiana Martino described. “Combining several microscopic techniques, including FRET imaging microscopy, fluorescence correlation spectroscopy (FCS), fluorescence imaging microscopy (FLIM) and stochastic optical reconstruction microscopy (STORM), we demonstrated effective binding of DNA-nanoswitch molecules to NF-κB proteins.” In nanometer resolution it was possible to observe a DNA nanoswitch in a bound, unbound, and degraded state.
The presented approach can be extended to other DNA nanostructures, and thus to investigate their intracellular dynamics and functionality.
Source: DOI: 10.1039/d0nr03087b