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Researchers hope to create a tablet drug for Huntington's. A brain chemical has been found that could improve the lives of people with Huntington's disease, scientists say. Mice tailored to develop the degenerative brain disease had fewer symptoms and declined at a slower rate when given Ciliary Neurotrophic Factor.

The team at Portugal's Centre for Neuroscience in Coimbra used gene therapy to reprogramme the brain to produce the chemical.

A UK team is now working to produce a tablet that has a similar effect. The research, published in the journal Experimental Neurology, is further evidence that the lack of certain "neurotrophic factors" are key to the progressive symptoms of Huntington's.

Late onset

The illness, which usually emerges when the patient is in their 40s, is caused by a faulty gene. Instead of producing the correct levels of the neurotrophic factors, the mutant gene suppresses production, and brain tissue in an area called the striatum dies.
Symptoms include mental disturbances and uncoordinated or involuntary movements.
The continuing loss of brain tissue eventually removes the ability to move, walk or even swallow, leading to death. Scientists have known the identity  of the gene responsible for Huntington's since 1993, but there is no cure for the disease.Patients can be screened for the mutated gene, but little can be offered in the way of treatment.

Chemical key

However, more recent research has pinpointed what the gene, and its mutated Huntington's version, actually do. Identifying the importance of neurotrophic factors in keeping the brain healthy has allowed scientists to work on producing ways of keeping the disease in check.
The Portuguese team used mice which have a copy of the key gene, and develop the disease in a very similar way to humans. In order to treat them, they developed a virus which is programmed to insert a new, correct copy of the gene into cells that it "infects". When this was injected into the mouse brain, enough cells began to produce the neurotrophic factor to make a difference to the symptoms of Huntington's. The progression of the disease in these mice was slowed down.

Long-term treatment

However, it is possible that, even using this method, that a human patient with Huntington's would need repeated injections into the brain over at least a 20 to 30 year period. So other researchers are hunting alternative ways of achieving the same effect.
Experts from Bristol University are working to identify molecules that will bind to the same "receptors" on the surface of brain cells as the neurotrophic factors.

Dr David Dawbarn, one of the Bristol researchers, said that this,if successful, could lead to drugs in tablet form which might have a similar effect to brain injections. He told BBC News Online: "It might not be practical for someone to have regular injections into the brain over the long-term."Hopefully we can find compounds that are equally effective."