A team of researchers has developed a very effective drug that could treat people with asthma. In the process, they may have found the primary cause of the disease, a discovery that could pave the way for the development of a new treatment over the next five years.
For the new study, which was published in the journal Science Translational Medicine on April 22, the researchers found that the calcium sensing receptor (CaSR) has a crucial role in causing the lung disease as it is responsible for triggering symptoms such as the narrowing of the airways and inflammation.
The researchers have likewise found the effectiveness of drugs called calcilytics that manipulate CaSR, which have been shown to reverse the symptoms of asthma in laboratory experiments. The drug is currently being used for treating osteoporosis.
"Asthmatic patients and allergen-sensitized mice expressed more CaSR in ASMs than did their healthy counterparts," the researchers wrote in their study. "Polycations induced hyperreactivity in mouse bronchi, and this effect was prevented by calcilytics and absent in mice with CaSR ablation from ASM. Calcilytics also reduced airway hyperresponsiveness and inflammation in allergen-sensitized mice in vivo."
Study researcher Daniela Riccardi from the Cardiff University School of Biosciences described the results of their study as exciting: they have found for the first time what links twitchiness in allergic asthma and the inflammation of the airways, which can be attributed to environmental triggers, which include cigarette smoke, car fumes and allergens.
"Our paper shows how these triggers release chemicals that activate CaSR in airway tissue and drive asthma symptoms like airway twitchiness, inflammation, and narrowing," Riccardi said. "Using calcilytics, nebulised directly into the lungs, we show that it is possible to deactivate CaSR and prevent all of these symptoms."
Study author Paul Kemp, also from Cardiff University, said that the identification of CaSR as a culprit of the disease means there could be an immense potential in the development of a new treatment not just for asthma but also for other lung diseases, such as chronic bronchitis and chronic obstructive pulmonary disease (COPD). These diseases are predicted to be the third biggest killers globally by 2020.
The findings of the study could also pave the way for calcilytics to be repurposed for use by asthma patients. The human trial for these drugs could start as early as within two years.
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