Scientists Build a Gene Switch That Can Be Turned On by Electromagnetic Fields

DNA - the molecule that carries an organism's genetic instructions - contains regulatory elements that control when and where specific genes are switched on or off. Researchers have long sought to use these elements to build "gene switches" that can be controlled remotely, using stimuli such as drugs, light, heat, ultrasound or electrical signals, for treating genetic disorders without surgery. Existing versions, however, offer limited control over the timing and duration of gene activity, drug-based switches can carry side effects, and light struggles to reach deep tissue.

A team led by Professor Jongpil Kim and doctoral student Yerim Hwang at Dongguk University's Institute for Stem Cells and Regenerative Medicine in South Korea has developed an electromagnetic field (EMF)-responsive gene switch, described in a study published in Cell. The researchers used the promoter of the Lgr4 gene - the DNA sequence that turns the gene on - to build the switch after single-cell RNA sequencing of mouse brain tissue showed that Lgr4 was uniquely activated by exposure to a low-frequency electromagnetic field.

To test the switch in living animals, the team linked it to a reporter gene that produces green fluorescent protein, then bred mice carrying it. Exposure to the electromagnetic field triggered strong fluorescence throughout the body, while targeted exposure produced localized activity in specific organs; when the field was switched off, gene activity returned to baseline within 24 hours. Using a genome-wide CRISPR-Cas9 screen, the researchers also identified a membrane protein called cytochrome b5 type B as the biological sensor that detects the electromagnetic field and triggers the switch - what Kim describes as the first reported molecular sensor for electromagnetic fields.

The team demonstrated several uses for the switch in mice, including an Alzheimer's disease model that separates brain aging from the buildup of amyloid-beta plaques, partial reprogramming of aged and progeroid cells that improved aging-related markers, and restored serotonin levels that reduced depression-like behavior. Further validation and testing are required before the approach could be considered for use in humans.