Neurodegenerative disease is an umbrella term for a range of conditions which primarily affect the neurons; in the human brain. Neurons are the building blocks of the nervous system which includes the brain and spinal cord. The team of scientists has shown experimentally, for the first time; how mutations ultimately set off an anti-viral like inflammatory response in cells that leads to cell death; over time, progressive neurological damage. This study investigates the outcomes of a mutation linked to Huntington’s disease; 20 other neurodegenerative diseases, including some forms of motor neuron disease.
But it also may have implications for the progression of neurodegenerative diseases which are not necessarily inherited; such as Alzheimer’s and Parkinson’s, which evidence suggests are by a similar inflammatory response to environmental triggers. “Together these conditions affect millions of families worldwide; there are no cures or effective treatments,” says project leader Rob Richards.
DNA repeat diseases
“If the new mechanism we have discovered proves to correct, it will transform the field, providing a different way of thinking about these diseases and offering new opportunities for medical intervention.” The so-called ‘DNA repeat diseases’ – named because of the repeat sequences found in the DNA of patients share many common features in their symptoms, but the mechanisms by which symptoms arise have previously thought to different for each.
What mutations are involving for some years; the set of outcomes that result, but, until now, they have not known how one leads to the other. This new research shows us how each of these diseases can be caused by the same underlying cellular pathway.” The study results center around RNA; the molecule in our cells which is the intermediate step between the DNA in chromosomes and the proteins that are the cells’ main functional components.
Blueprint producing RNA
The DNA provides a blueprint for producing RNA that is then normally ‘bar-coded’ to ensure cells; recognize it as “self”, distinguishing it from the RNA of a foreign invader, such as viruses. Using the experimental model fly Drosophila, Professor Richards and his team showed, ‘double-stranded RNA’ as foreign to the body, or “non-self”.
Therefore this elicits an anti-viral like, auto-inflammatory response that leads to neuronal destruction and death; in time causing progressive neurological damage. “The abnormal RNA is made from regions of repeating DNA sequences that are in greater numbers in people affected with Huntington’s and some other neurodegenerative diseases.” Professor Richards says there are existing drugs for other types of auto-inflammatory disease; which may prove to effective in treating the symptoms of these diseases, by inhibiting the anti-viral inflammatory response.