The Role Human Lung Tissue Plays in Respiratory Research

June 19, 2019

You don’t need to be a respiratory researcher to be impressed by how efficiently the human lungs work. Together, the average lungs weigh in at less than three pounds, and yet, allow a healthy person to take 17,000 breaths a day. It is only natural that researchers look to lung tissue as they attempt to find treatments and cures for respiratory diseases.

Researchers need access to biospecimens of lung tissue in order to study lung diseases at both the cellular and molecular level. As one might imagine, recruiting lung tissue donors is not an easy process. Still, it is necessary to have enough lung tissue available to analyze and research possible medical interventions for patients whose lungs are diseased or otherwise failing.

Researchers around the globe are dedicated to discovering how to keep lungs healthy longer and how to help regenerate lungs that are failing. In order to collect living lung tissue, researchers turn to patients who are about to undergo lung surgery. If a patient agrees, surgeons collect blood and tissue that would otherwise have been discarded following surgery. Most of the patients involved suffer from chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis, or interstitial fibrotic lung disease. Other conditions include cystic fibrosis and pulmonary hypertension. Samples may only be taken from patients who have given consent.

Once a sample is secured, an entire team works together to gather all the information they can possibly glean. Everyone – from lab techs to radiologists and data coordinators – play a role in assessing donated tissue. It is only in studying live tissue that researchers can better understand what happens as those tissues begin to break down and hopefully, come up with ways to prevent it from happening. The greater the number of tissue donors, the better researchers can study lung diseases at its varying stages.

Like a before and after picture in a glossy magazine, researchers also compare lung tissue from healthy adults to that of patients who died of respiratory ailment. In analyzing the differences between the two, they hope to find the point at which lungs became diseased and attempt to head it off.

According to the National Institutes of Health (NIH), the study of lung tissue is vital. Currently in the United States, one-fifth of all deaths are linked to lung disease, and lung disease is about to become the third leading cause of death and disability. Research, such as that conducted on lung tissue, is needed to better predict diseases before symptoms arise and to begin to target new treatments specifically designed to treat them.

The good news in the midst of the gloomy predictions is that NIH believes that the respiratory community is making rapid progress in pulmonary science. While there’s no single reason for this, the role of having access to lung tissue in research should not be underestimated. It is only by studying lung tissue at its molecular level that researchers find the answers they need.

Advances in molecular biology are helping to redefine pulmonary diseases. For example, molecular markers have proven useful in diagnosing cystic fibrosis, respiratory infections, and antitrypsin deficiency. None of this would be possible without access to lung tissue.

By studying tissue, researchers have access to molecular phenotypes, also referred to as “fingerprints.” These fingerprints make it possible to identify hundreds of molecular changes. The differences between a diseased lung and a normal lung can be determined in DNA, RNA, and a metabolites. It is through studying these complex molecular phenotypes that researchers can detect common genetic variants. The question is whether the variants are the root cause of why some people develop lung disease while others do not.

Consider all the times you have heard a smoker say something along the lines of, “I’ll be fine. My grandfather smoked his entire life and lived to be 104.” The answer as to why a disease impacts one person but not the next may, in fact, lie in genetic variants. That is what researchers want to know.

Working with lung tissue also allows researchers to study how environmental factors impact the lungs. By exposing a healthy sample to environmental factors, researchers are able to watch in real time how (and if) the lung tissue changes. The hope is that further research may help the scientific community better understand the way environmental factors drive the development of lung diseases.

In the not so distant future, it is possible that researchers will have unlimited access to lung tissue. That is because in 2018 bioengineered lungs were successfully implanted into pigs for the first time. These lungs enabled the pigs to breathe normally, although study is ongoing. If scientists are able to mass produce bioengineered lung tissue, it offers respiratory researchers another tool in their fight against lung disease.

While the scientific community waits to learn more about bioengineered lungs and conduct further study into the role stem cells play in lung regeneration, they will continue to learn more about the causes and prevention of disease by studying lung tissue.