Breakthrough Asthma Study Reveals a Trigger We've Never Noticed Before.

More than 1,000 people die each day from asthma, a condition that restricts the airway and prevents sufficient oxygen from getting where it's needed.

In addition to an asthma attack's tightening of the channels into the lungs, inflammation of the lining and increased mucus production exacerbate the problem for weeks or months at a time, putting people at risk of triggering ongoing episodes.

Scientists have now shown for the first time how mechanical constriction of the airways during an asthma attack overcrowds cells in the lining. These cells are squeezed out and killed, which triggers inflammation, mucus secretion, and airway barrier damage.

"Without this barrier, asthma sufferers are far more likely to get long-term inflammation, wound healing, and infections that cause more attacks," says cell biologist Jody Rosenblatt from King's College London, senior author of the new study.

"By understanding this fundamental mechanism, we are now in a better position to prevent all these events. Our discovery is the culmination of more than ten years' work."

And they have a promising solution: a compound that blocks this squeezing out of overcrowded cells – called epithelial extrusion – in the airway lining of mice. Though its safety has yet to be tested in humans, Rosenblatt and her colleagues from the US, UK, and Spain think this could lead to entirely new approaches to preventing asthma attacks, not just treating inflammation.

Asthma affects around 300 million people worldwide. Most experience wheezing, coughing, shortness of breath, and chest tightness. Everything from pollen and dust mites to pet dander and smoke to exercise and even cold air can set off these symptoms, which range in severity.

No cure exists, but some treatments, particularly those that target airway inflammation, can control asthma symptoms. Inhaled bronchodilators to open up airways and corticosteroids to reduce inflammation are often used.