The mini-lung: new results
Despite being tiny, it gives so much hope to millions of people with lung damage: the mini-lung. It grows in the laboratory from stem cells and is no bigger than a pinprick, but it is very important. "With the mini-lung, we can look for treatments for lung damage in a very targeted way," Professor Carla Kim at the Boston Children's Hospital explains. 'We have also been investigating how we can repair damaged tissue with the mini-lung. The insights follow each other rapidly!"
"We learn more and more about lungs and what goes wrong with diseases like COPD," Kim says. "This knowledge is key when it comes to developing new treatments with the mini-lung. For example, we were thrilled when our Accelerate colleague Professor Ed Morrisey, of the University of Pennsylvania, discovered a new type of stem cell. It exists only in human lungs and is known as the Respiratory-Airway-Secretory-Cell (RASC). The RASC appears to play a significant role in repairing damaged alveoli. It may well be the missing piece of the puzzle for treating COPD. "
Refining the recipe
"At the moment, we are still working hard on the mini-lung itself," Kim says. 'To make this mini-organ, we must add substances that tell the stem cells to form a mini-lung. It's like a 'recipe', really. We know the recipe for growing mini-airways. We are now refining the recipe for growing the mini-alveoli. "
Cells need each other
The alveoli are more difficult to grow in miniature size at the laboratory. Kim: "It seems that the stem cells need the other lung cells to work properly. They then give off signals that tell the stem cells what to do. So we don't fully understand how this works yet. We are still learning every single day. Just look at the discovery of the RASC. At the moment, we can only have mini-lungs if we grow the other lung cells with the stem cells. "This is more of a temporary recipe for the mini-lung.
Interesting discoveries are already being made with this temporary recipe for the mini-lung. Professor Kim: "We already know that the cells of the mini-lung settle in the right place in the lungs. We also know that they work there like normal lung cells. And when lungs are damaged, they help undo this damage. The next step is to explore how the cells of the mini-lung act in lung tissue with COPD. "
This temporary mini-lung can also be used for medicine research. With this mini-lung, Reinoud Gosens, Professor at the University of Groningen and Accelerate researcher, has discovered that the medicines prostaglandin E2 and I2 can help grow stem cells. In people with lung damage, the stem cells no longer work effectively, so they can no longer undo the damage. These medicines may be able to change that. He will continue to investigate this idea.
Researchers must now discover how to grow the mini-lung without any other lung cells. The laboratory of Professor Hans Clevers is involved in this. Kim: "We need to know exactly which substances and nutrients we need to add. Otherwise, it is not safe for humans and side effects may occur. If we want to use the mini-lung to treat lung damage, it must be easy to grow and be exactly the same every time. If you grow the mini-lung with other cells, differences can still present themselves. Especially if you grow them on a large scale.
Accelerating medical breakthrough
Kim is leading the Lung Regeneration research programme at Longfonds (Lung Foundation Netherlands). Top researchers worldwide are working together to find out what goes wrong with COPD and to develop the mini-lung. They are investing best efforts to accelerate a medical breakthrough.