mGluR5 gene editing

Expression of a protein (blue-green, left) associated with fragile X syndrome is suppressed (right) in the brains of mice treated with CRISPR gene-editing molecules. Credit: B. Lee et al./Nature Biomed. Eng.

Biotechnology

CRISPR with a heart of gold helps ailing mice

Gene-editing molecules ride gold nanoparticles into the brain.

Scientists are mining gold for new ways to treat diseases in the brain.

The gene-editing system CRISPR–Cas9 holds promise as a tool to counteract mutations associated with disease. But the system’s key molecules are usually delivered by viruses, which can trigger side effects.

As a non-viral alternative, Hye Young Lee at the University of Texas Health Science Center at San Antonio, Niren Murthy at the University of California, Berkeley, and their colleagues tested a new version of CRISPR–Cas9. Called CRISPR–gold, it uses gold nanoparticles rather than viruses to deliver gene-editing molecules. The researchers injected CRISPR–gold into two brain areas in mice and found that the system edited genes in several major cell types.

The researchers tried the technique on genetically engineered mice that are a model for fragile X syndrome, a genetic condition associated with autism-spectrum disorders. CRISPR–gold quieted the overactive gene linked to the syndrome and suppressed the animals’ abnormally repetitive behaviours.