Researchers have made a new discovery that may help with the development of treatments for Huntington’s disease. By modifying huntingtin proteins, the team was able to prevent Huntington’s disease symptoms in mice. The findings are in a paper just published in the Journal of Clinical Investigation.
Huntington’s disease is an inherited neurodegenerative disorder with no cure. Symptoms of the disease include jerky, uncontrollable movements and dementia. The disease is caused by a mutation in the Huntingtin gene. The mutation forces huntingtin proteins to fold improperly and the abnormal proteins cause damage in the brain. This leads to the gradual degeneration of brain cells and is fatal.
Researchers were able to modify the huntingtin protein in laboratory mice. By using a technique called phosphorylation, they added phosphate groups to the proteins. This made the proteins much less toxic to brain cells. Furthermore, the addition of a phosphate group made it possible for the surrounding cells to eliminate the modified huntingtin proteins. By adding the phosphate group to a specific section of the protein, disease symptoms were completely prevented in mice. Mice treated this way showed few or no signs of Huntington’s disease. Behaviorally, they were identical to the healthy control group. Brain dissections confirmed that the treatment prevented neuron death in the brains of the treated mice.
The research team was able to show that phosphorylating the abnormal huntingtin proteins prevented brain damage in mice. The authors speculate that the addition of phosphate groups makes the proteins fold in a way that allows for their removal by other cells. Neurons can remove the dangerous proteins before they have a chance to damage brain cells. This finding has important implications in the treatment of Huntington’s disease, which currently has no cure. The team also believes that understanding protein removal pathways could help treat other neurodegenerative disorders.
Ian H. Kratter et al. Serine 421 regulates mutant huntingtin toxicity and clearance in mice. Journal of Clinical Investigation (2016).