Newswise – MINNEAPOLIS / ST. PAUL (03/12/2024) – Researchers at the University of Minnesota Twin Cities may have discovered a mechanical explanation for the instability observed in the lungs during acute respiratory distress syndrome (ARDS), particularly after respiratory illnesses such as COVID -19 or pneumonia.
The research was recently published in the Proceedings of the National Academy of Sciences (PNAS), a peer-reviewed journal of the National Academy of Sciences.
There is currently no known cure for ARDS, a life-threatening lung injury that causes fluid to enter the lungs. Researchers in this study say up to two-thirds of all patients who died from COVID-19 had ARDS. There is no clear reason why certain people with severe respiratory disease may develop ARDS while others may not, but researchers in this study sought an answer.
They identified levels of a lysolipid – a byproduct of the immune response to viruses and bacteria – that can have significant effects in adults suffering from ARDS. Increased concentration of this chemical eliminates surfactant, a complex of fats and proteins that is created in the lungs. The result is uneven inflation of the lungs and ultimately shortness of breath in adults.
“This study examined the relationship between the concentration of lysolipid in the lungs. Once this fluid reached a certain level, it began to cause severe impacts,” said Professor Joseph Zasadzinski of the University of Minnesota’s Department of Chemical Engineering and Materials Science and lead professor of the research.
“Normally the average person doesn’t have to think about this, but if a virus or infection affects your pulmonary surfactant system and you end up in the hospital, it could come to mind very quickly,” Zasadzinski added
There is a natural amount of these lysolipids in the human body, and as long as they remain below a certain concentration, the average person can breathe normally. When someone has a severe infection, these lysolipids increase, which can cause shortness of breath. Once a patient moves in this direction, there are not many options to reverse these symptoms.
“This research shows frequency dependence, or how quickly you open and close the lungs. This could help doctors customize the treatment process for each individual patient,” said Clara Ciutara, a 2023 graduate student in chemical engineering and materials science and first author of the study.
Previous research into neonatal respiratory distress syndrome (NRDS) in premature infants found that it can be treated by the introduction of replacement pulmonary surfactant, but this was not the case in adults. It is the amount of lysolipid that determines the effect of the surfactant in the lungs, not the breakdown of the lung surfactant present.
The next step in the research will be to translate these ideas into a clinical setting and test whether they can manipulate certain molecules to make them less active or to stick to a specific location. This could help reduce the concentration of lysolipids to a threshold that could potentially reverse the symptoms of ARDS and put people on the road to recovery.
In addition to Zasadzinski and Ciutara, the research team included postdoctoral fellow Steven V. Iasella from the Department of Chemical Engineering and Materials Science at the University of Minnesota, NIH, graduate student Boxun Huang, and former postdoctoral fellow Sourav Barman.
This work is supported by a grant from the National Institutes of Health (NIH) Heart, Lung, and Blood Institute. All microscopy images were acquired at the University Imaging Center at the University of Minnesota
To read the full research report titled “Evolution of interfacial mechanics of lung surfactant mimics progression of acute respiratory distress syndrome,” visit the Proceedings of the National Academy of Sciences (PNAS) website.. A commentary on the research can also be found on the website PNAS website.