The erasable markers are cleaved by a targeted enzyme that acts like molecular scissors, removing the background signal and enabling fresh readings.

RMAs are designed to be sensitive to a specific protease, separating the signal domain from the long-lasting domain to decay background signal within minutes.

This approach could extend marker detectability or erase background signals, enabling clearer, minimally invasive monitoring of brain activity and treatment responses, with broader potential applications in cancer or lung disease through non-invasive tests.

Potential clinical and research uses include more precise monitoring of treatment responses with minimally invasive tests and broader diagnostics such as detecting tumors or lung disease via urine tests.

Rice University bioengineers have developed erasable serum markers of activity (RMAs) that travel from targeted brain cells into the bloodstream to indicate gene activity and can be measured with a simple blood test.

Funding for the study came from the NIH and the NSF, with authors noting the content reflects their views and not necessarily those of the funders.

In animal models, administering a specific cleaving enzyme removes about 90% of the background RMA signal within 30 minutes, enabling detection of subtle gene-expression changes and allowing repeated cycles to track dynamics over time.

A single injection of the cleaving enzyme rapidly clears most background signal, enabling timely observation of subsequent gene-expression changes.

The work suggests in-body editing of markers could tune their behavior for various diagnostic purposes beyond neurology, extending diagnostic readouts and temporal resolution.

The team demonstrated repeated resetting and reappearance of the RMA signal, yielding a clearer picture of how brain gene activity evolves over time.

Traditional RMAs persist in blood for hours, but the new approach allows the signal to be reset inside the bloodstream, improving temporal precision.

Published in Proceedings of the National Academy of Sciences, the study marks a step toward more temporally resolved biomarkers and aligns with Rice University’s brain initiatives and the new Rice Brain Institute.