Researchers at the University of Valencia in Spain have developed a new air-liquid interface (ALI) exposure system designed for the continuous exposure of airway epithelial cells to gases, specifically nitric oxide (NO). The system, detailed in a recent publication, aims to more accurately mimic the conditions within the human respiratory system and overcome limitations of existing in vitro models.
Current methods for studying airway epithelial cell responses often rely on submerged cell cultures or ALI cultures that lack continuous gas control. These limitations can affect cellular differentiation and function, potentially skewing research results. The newly developed system addresses these issues by providing a controlled environment where cells are exposed to a constant flow of gas, allowing for more physiologically relevant investigations.
The research team, led by María Amparo Bayarri and Javier Milara, highlighted the importance of the airway epithelium as a critical interface between the body’s immune system and the external environment. According to a related study published in Paediatr Respir Rev, the respiratory epithelium not only acts as a physical barrier against pathogens and irritants but also actively orchestrates immune responses. Understanding how this barrier reacts to various stimuli, such as inhaled gases, is crucial for developing effective treatments for respiratory diseases.
Nitric oxide, the focus of the new system, plays a complex role in airway physiology. The researchers’ function builds on existing knowledge that the airway epithelium maintains its structure through tight junctions, adherens junctions, and desmosomes, preventing the diffusion of substances between cell surfaces. The ALI system allows for the study of how NO impacts these junctions and overall epithelial function.
The development of this system comes as researchers increasingly recognize the cellular and functional heterogeneity of the airway epithelium. A 2020 article in Nature emphasized that different cell subsets within the airway epithelium play distinct roles in maintaining respiratory homeostasis and responding to environmental challenges. The ALI system, by providing a more controlled environment, could facilitate investigations into the specific responses of these different cell types.
Even as current studies often utilize airway epithelial cell lines, the researchers acknowledge that these may not fully represent the complexity of the in vivo epithelium. Primary submerged cultures, they note, can respond differently to pollutants compared to ALI cultures. The new system aims to bridge this gap by offering a more realistic model for studying airway responses.
The University of Valencia team has not yet publicly announced specific applications of the system beyond its development and initial characterization. Further research is expected to explore the system’s utility in studying the effects of air pollution and other environmental factors on airway epithelial function.
