by American Physiological Society

Graphical abstract. Credit: American Journal of Physiology-Lung Cellular and Molecular Physiology (2023). DOI: 10.1152/ajplung.00389.2022

New research finds extracellular vesicles are present in the lungs of premature babies and may be involved in lung development and as a predictor of lung disease. The study is published ahead of print in the American Journal of Physiology-Lung Cellular and Molecular Physiology.

Approximately 75% of premature infants born between 22 and 24 weeks' gestation develop bronchopulmonary dysplasia, a chronic disease that occurs when the lungs are not mature enough at birth to support normal function. Extracellular vesicles—the tiny particles released from all cells that facilitate intercellular communication and may aid in other physiological processes—have been found previously in the lungs, but it's not clear what role they play in lung development.

"Because proper lung development requires tremendous cellular and structural changes, it is possible that [extracellular vesicles] are both markers and mediators of these dynamic processes," the researchers of the current study wrote.

The research team analyzed samples collected from the airways of premature infants—gestational ages ranged from just over 22 weeks to just under 35 weeks—during standard treatment procedures for respiratory problems, such as intubation. Of the 34 four samples examined, 27 of them contained extracellular vesicles.

The extracellular vesicles contained epithelial and immune proteins across all stages of lung development. Babies born in the earlier stages of lung development had higher CD24 expression, a protein expressed by a diverse population of cells, with CD24-loaded extracellular vesicles gaining recent attention for their therapeutic role in COVID-19. In addition, the newborns who developed bronchopulmonary dysplasia also had higher levels of CD14 extracellular vesicles, which have been identified as a potential marker for disease severity in adults with acute lung injury.

"Given what is known about lung development and [bronchopulmonary dysplasia], it is interesting to hypothesize how [extracellular vesicles] carrying the markers identified in this study might participate in normal physiological and pathological processes," the researchers wrote. "This work provides a foundation for future directions to elucidate the role of [extracellular vesicles] in lung development and injury, including determination of the role of [extracellular vesicles] throughout the stages of lung development."

More information: Meaghan A. Ransom et al, Developmental trajectory of extracellular vesicle characteristics from the lungs of preterm infants, American Journal of Physiology-Lung Cellular and Molecular Physiology (2023). DOI: 10.1152/ajplung.00389.2022

Provided by American Physiological Society