Huntington’s disease is an inherited neurological disease that affects about 30, 000 Americans and for which there is no effective treatment or cure. An important step to developing new treatments was announced last week when scientists at the Yerkes National Primate Research Center in Atlanta published a paper (1) describing how they genetically modified monkeys to carry the defective huntingtin gene (the mHtt gene) that causes the disease. This is the first time that monkeys have been genetically modified to have a human disease and the achievement of Dr. Anthony Chan and his colleagues has received widespread news coverage.
In the past few years research using a range of transgenic organisms, including flies, nematode worms and mice, has made important contributions to our knowledge of how the mHtt gene causes Huntington’s disease (2), and transgenic models have also been vital to the evaluation of potential treatments (3). These models do not however fully replicate the cognitive deterioration and behavioral problems that are associated with Huntington’s disease, and can’t be used to study all of the changes that occur in different tissues as the disease slowly progresses. The genes, physiology and lifespan of monkeys are far closer to that of humans, so it is hoped that a monkey model of Huntington’s disease will provide new insights into the development of the disease to complement and confirm the observations made using more distantly related species. The monkey model will also play an important role in the preclinical testing of new treatments for Huntington’s disease, since their effect on cognitive abilities can be more readily assessed.
It is important to note that this is just a first step to the development of a monkey model of Huntington’s disease, further refinement will be necessary before it is ready for use in research. Other organisms such as flies and mice will continue to account for most animal research into Huntington’s disease. Nevertheless Speaking of Research congratulates Dr. Chan and his team on their success so far.
In related news Dr. Antony Fauci, director of the National Institute of Allergy and Infectious Diseases, has said that the National Institute of Health (NIH) is planning for a significant increase in primate research as the focus in HIV research shifts to studies aimed at getting a better understanding of how the disease infects its victims and progresses to AIDS (4). We are glad to hear that the NIH is consulting with scientists and drawing up plans to facilitate this important work at its National Primate Research Centers.
1) Yang S.H. et al. “Towards a transgenic model of Huntington’s disease in a non-human primate.” Nature. 2008 May 18. [Epub ahead of print].
2) Sipione S. and Cattaneo E. “Modeling Huntington’s disease in cells, flies, and mice.” Mol Neurobiol. Volume 23(1), pages 21-51 (2001).
3) Harper S.Q et al. “RNA interference improves motor and neuropathological abnormalities in a Huntington’s disease mouse model.” Proc. Natl. Acad. Sci. USA Volume 102(16), pages 5820-5825 (2005).
4) “US plans more primate research” Nature Volume 453 (7194), page 439 (2008)