Orthogonal Activation of RNA‐Cleaving DNAzymes in Live Cells by Reactive Oxygen Species

Abstract

RNA‐cleaving DNAzymes are useful tools for intracellular metal‐ion sensing and gene regulation. Incorporating stimuli‐responsive modifications into these DNAzymes enables their activities to be spatiotemporally and chemically controlled for more precise applications. Despite the successful development of many caged DNAzymes for light‐induced activation, DNAzymes that can be intracellularly activated by chemical inputs of biological importance, such as reactive oxygen species (ROS), are still scarce. ROS like hydrogen peroxide (H2O2) and hypochlorite (HClO) are critical mediators of oxidative stress‐related cell signaling and dysregulation including activation of immune system as well as progression of diseases and aging. Herein, we report ROS‐activable DNAzymes by introducing phenylboronate and phosphorothioate modifications to the Zn2+‐dependent 8–17 DNAzyme. These ROS‐activable DNAzymes were orthogonally activated by H2O2 and HClO inside live human and mouse cells.

Recent Advances on DNAzyme‐Based Sensing

“…Further by combination of the caged DNAzymes with upconversion nanoparticles (UCNPs), they realized the activation of DNAzyme activity in an NIR region [44] . In 2019, the Xiang Lab constructed an reactive oxygen species (ROS) activated DNAzyme by incorporation PS or phenylboronate groups at specific backbone positions in 8–17 DNAzyme by the efficient chemical conjugation reaction [45] . The Shionoya group demonstrated the concept of sharp switching of DNAzyme activity by introducing a Cu II ‐mediated carboxyimidazole base pair (ImC−Cu II −ImC) in the splitted catalytic core of E5 DNAzyme [46] .…”