Probe detects H₂O₂ in living cells

Interest in monitoring hydrogen peroxide in living cells has increased considerably now that it is not just considered a marker for oxidative stress and damage but also thought to be a messenger in cell signaling. However, H₂O₂ is challenging to monitor in real time because it is so reactive and difficult to distinguish from other oxygen species. Now, Christopher J. Chang and coworkers at the University of California, Berkeley, report two new boronate-based fluorophores-PG1 (shown) and PC1-for detecting H₂O₂ in living cells (Nat. Chem. Biol., DOI: 10.1038/nchembio871). Unlike diboronate-based probes, these molecules are turned on when H₂O₂ removes the single boronate group, releasing the fluorescent dye. Using PG1, the researchers measured H₂O₂ produced in human epithelial cancer cells in response to epidermal growth factor. They then showed that they could also detect H₂O₂ in live neurons. Their data suggest that the neurons generate H₂O₂ through a pathway similar to the one used by cancer cells.