A genetic switch to keep a check on asthma has been identified. If successful, this genetic switch could help prevent asthma before it even develops. The findings can challenge the current understanding of the condition.
Scientists at the University of Southampton have discovered a novel and potential way to prevent asthma at the very origin of the disease. They analysed the impact of the gene ADAM33, which is associated with the development of asthma. ADAM33 makes an enzyme which is attached to cells in the airway muscles. But when the enzyme loses its anchor to the cell surface, it is prone to going rogue around the lung. This in turn causes poor lung function in people with asthma.
‘Gene ADAM33 is associated with the development of asthma. Switching off the gene could help prevent asthma even before it develops.’
The study published in The Journal of Clinical Investigation (JCI)
shows that in human tissue samples and mice, by switching off ADAM33 or preventing it from going rogue, the features of asthma including airway remodelling, with more muscle and blood vessels around the airways, twitchiness and inflammation, will be reduced.
The first study showed that rogue human ADAM33 causes airway remodelling resulting in more muscle and blood vessels around the airways of developing lungs, but it did not cause inflammation. This does not cause problems though. However, when a house dust mite allergen was introduced, airway remodelling and allergic airway inflammation were more significantly enhanced.
"This finding radically alters our understanding of the field, to say the least. For years we have thought that airway remodelling is the result of the inflammation caused by an allergic reaction, but our research tells us otherwise," Associate Professor in Respiratory Medicine at the University of Southampton, Hans Michel Haitchi.
Scientists had earlier thought it was allergens like pollens that triggered asthma attacks, but they could never explain many people with allergies never got asthma.
Another study where remodelling of the airway was shown in mice that had ADAM33 switched on in utero. When ADAM33 was switched off the airway remodelling was completely reversed. The scientists also studied the impact of house dust mite allergen on mice having asthma features but had the ADAM33 gene removed.
It was observed that mice that had their rogue gene removed, airway remodelling and twitchiness as well as airway inflammation rates were significantly reduced by 50% and 35% respectively.