Research being undertaken at Cardiff University claims to give fresh hope to asthma sufferers. The scientists have discovered protein molecules called calcium-sensing receptors which are more numerous in asthma sufferers.
Asthma causes the immune system to see substances such as dust or pollen as a threat. The body’s immune system responds to the attack by mobilising white blood cells and inflammatory proteins which collect in the airways. This inflammation constricts the airways which can cause breathlessness. The inflammatory proteins can stimulate the calcium-sensing receptors which can further exacerbate the inflammation of the air passages.
A drug originally developed for osteoporosis called Calcityrol is known to suppress the calcium-sensing receptors and can reduce the inflammation of the air passages but it has not yet been shown that the drug would also reduce the inflammatory response triggered by the immune system. Calcityrol was not proved to be effective against osteoporosis but researchers believe that the drug could be effective for asthma sufferers. However they need to find a safe but effective dosage that could be delivered straight to the lungs.
The study was funded by Asthma UK, the Cardiff Partnership fund, Marie Curie Initial Training Network, the Biotechnology and Biological Sciences Research Council and the US National Institutes of Health and carried out by researchers from the Open University, the Mayo Clinic, the University of California, San Francisco School of Medicine in the US and the University of Manchester, King’s College and Cardiff University from the UK. Four of the authors are co-inventors of a patent for the use of calcium-sensing receptors in the treatment of inflammatory lung diseases.
The study has been published in the peer-reviewed journal Science Translational Medicine. The research is in its early stages, using samples of human lung tissue and mice models. The researchers have proven that when the body is engaged in an inflammatory response to a threat, the number of calcium-sensing proteins is increased in the airways, causing further inflammation.
The research may not prove effective for all types of asthma. It is unclear whether all people with asthma have increased incidence of calcium-sensing proteins. It is not yet known how long the calcilytic drug will have an effect.
The researchers have claimed that using this study may enable them to produce a new drug as a treatment for asthma possibly within five years.
Yarova PL, Stewart AL, Sathish V, et al. Calcium-sensing receptor antagonists abrogate airway hyperresponsiveness and inflammation in allergic asthma. Science Translational Medicine. Published online April 22 2015