Mice with neurodegenerative diseases have been successfully treated with gene therapy, according to research published online in EMBO reports. Using lentivirus vectors, scientists were able to administer a therapeutic enzyme to treat spinocerebellar ataxia, a neurodegenerative disease that currently has no cure.
Mutations in the DNA sequence of several genes cause the proteins they encode to contain abnormally large amounts of the amino acid glutamine. Over time, the build up of polyglutamine aggregates leads to neurological degeneration and the onset of disease symptoms. Hirokazu Hirai and co-workers artificially overexpressed CRAG - the enzyme that naturally assists in breaking down the polyglutamine aggregates - in the affected mice, which where then able to clear the aggregates. Subsequently, neurons were rescued from degeneration and the disease symptoms markedly alleviated.
Polyglutamine diseases, such as spinocerebellar ataxia or Huntington's disease, are not fatal, but the symptoms and complications they cause result in a very poor quality of life and a reduced life expectancy for those affected. The team hopes that their work in mice can be developed into a clinical treatment for the nine types of polyglutamine disease that result from these kinds of genetic errors.
Hirokazu Hirai (Gunma University Graduate School of Medicine, Japan)
(C) EMBO press release.
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