A chemical found in plants could reduce the symptoms of the rare muscle disease, spinal muscular atrophy, which leaves children with little or no control of movement in their lower limbs.
Scientists at Keele University have contributed to an international study led by the University of Edinburgh showing that a plant pigment called quercetin – found in some fruits, vegetables, herbs and grains – could help to prevent the damage to nerves associated with this childhood form of motor neuron disease. Their findings, published in the Journal of Clinical Investigation, could pave the way for new treatments for spinal muscular atrophy (SMA), which is a leading genetic cause of death in children.
The team found that the build-up of a specific molecule inside cells – called beta-catenin – is responsible for some of the symptoms associated with the condition. In tests on zebrafish, flies and mice conducted at seven UK centres including The Robert Jones and Agnes Hunt Orthopaedic Hospital NHS Foundation Trust (RJAH) in Oswestry, the study found that treating the disease with purified quercetin – which targets beta-catenin – led to a significant improvement in the health of nerve and muscle cells. Quercetin did not prevent all of the symptoms associated with the disorder but researchers hope that it could offer a useful treatment option in the early stages of disease. They now hope to create better versions of the chemical that are more effective than naturally-occurring quercetin.
Dr Heidi Fuller from Keele University, who was part of the research team, comments: “This research has made significant inroads into finding a solution to SMA, which is a rare, but potentially fatal, condition in young children. The next stage will be to find a chemical version of quercetin, which will be more effective in combating the symptoms of the disease.”
SMA is caused by a mutation in a gene that is vital for the survival of nerve cells that connect the brain and spinal cord to the muscles, known as motor neurons. Until now, it was not known how the mutation damages these cells and causes disease.
The study reveals that the mutated gene affects a key housekeeping process that is required for removing unwanted molecules from cells in the body. When this process doesn’t work properly, molecules can build-up and cause problems inside the cells.
Doug Henderson, acting Managing Director of The Jennifer Trust for Spinal Muscular Atrophy welcomed the development, expressing caution regarding timescales, saying, ‘This is clearly a very interesting and exciting development but we must be mindful that it could be many years before this translates into something more tangible for future generations of people coping with spinal muscular atrophy.’
Children with SMA experience muscle wastage, with loss of mobility and control of their movements. It affects one in 6000 babies and around half of children with the most severe form will die before the age of two. Less severe forms survive into adulthood though not without mobility problems.
Professor Tom Gillingwater from the University of Edinburgh, who led the study, said: “This is an important step that could one day improve quality of life for the babies affected by this condition and their families. There is currently no cure for this kind of neuromuscular disorder so new treatments that can tackle the progression of disease are urgently needed.”
Dysregulation of ubiquitin homeostasis and ?-catenin signaling promote spinal muscular atrophy, Thomas M. Wishart, Chantal A. Mutsaers, Markus Riessland, Michell M. Reimer, Gillian Hunter, Marie L. Hannam, Samantha L. Eaton, Heidi R. Fuller, Sarah L. Roche, Eilidh Somers, Robert Morse, Philip J. Young, Douglas J. Lamont, Matthias Hammerschmidt, Anagha Joshi, Peter Hohenstein, Glenn E. Morris, Simon H. Parson, Paul A. Skehel, Thomas Becker, Iain M. Robinson, Catherina G. Becker, Brunhilde Wirth and Thomas H. Gillingwater, J Clin Invest. DOI:10.1172/JCI71318, published 3 March 2014.