Huntington’s Disease Discovery Opens Door to a New Class of Treatments
Berkeley Lab researchers identified excessive DNA damage as a key driver of Huntington’s disease and showed an antioxidant can reverse neuron damage in mice, opening a new treatment pathway.
Scientists at Lawrence Berkeley National Laboratory found that Huntington’s disease (HD) involves widespread breaks in DNA strands, particularly in brain neurons, which had not been previously recognized as a primary factor in the condition. The study, published in Nature Communications, links these breaks to the disease’s progression, where neurons in the striatum die, causing cognitive and physical decline. Researchers observed that the more DNA damage accumulates, the more severe the symptoms become, suggesting a critical mechanism behind HD’s fatal effects.
The team demonstrated that treating HD mice with an antioxidant compound, XJB-5-131, reduced DNA damage, preserved neuron function, and alleviated disease symptoms without altering the mutated gene or its expansion. This approach contrasts with prior efforts that focused on gene editing or blocking the mutant protein, which have not yet yielded effective human treatments. The antioxidant works by neutralizing harmful byproducts from cellular energy production, which contribute to DNA damage in HD.
Researchers confirmed that the normal huntingtin protein interacts with DNA repair enzymes, but the mutated version suppresses their activity, leading to unchecked DNA breaks. This suppression occurs independently of the gene’s CAG repeat expansion, revealing a parallel disease pathway that had been overlooked. The discovery explains why previous treatments targeting only the genetic mutation failed to stop neurodegeneration, as the DNA repair failure was not addressed.
The findings have sparked interest in testing antioxidants in human cells, with plans to use patient-derived neurons to validate the mechanism before clinical trials. While the antioxidant alone may not fully cure HD, researchers suggest it could complement future gene therapies. The study, supported by the National Institutes of Health, marks a significant step toward new treatment strategies for a disease with no current cure.