Introduction: Ventilator-induced lung injury (VILI) is an acute lung injury caused or exacerbated by mechanical ventilation. Despite advances in understanding the pathobiology of VILI, the initiation and regulation pathways of the associated inflammatory responses remain unclear. Additionally, genetic variations may increase the risk of lung injury, but no biomarkers or therapeutic targets are currently used. Moreover, there is currently no clear treatment method except preventive methods such as lung protection ventilation and use of muscle relaxants.
Methods: An in vitro model was developed using A549 cell lines, representing type II alveolar epithelial cells. The cells were divided into low pressure (20 mmHg) and high pressure (60 mmHg) groups. Flexible-bottomed culture plates with six wells each (BioFlex® Culture Plates) were used to simulate mechanical ventilation conditions. An electrical circuit was developed to inject air at a predetermined pressure and duration into the culture plates. The system included an Arduino board to control the airflow, pressure gauges for monitoring, and an acrylic chamber to ensure a sealed environment. Apoptosis levels were measured using Muse Annexin V & Dead cell assays, with statistical analysis conducted on results from all six wells in each group.
Results: The high-pressure group showed a significant increase in both total apoptosis (P=0.004875) and late apoptosis (P=0.040247) compared to the low-pressure group, while early apoptosis did not show a statistically significant difference (P=0.943211). The most pronounced differences were observed in wells located at the center of the culture plates.
Conclusions: The findings suggest that high-pressure mechanical ventilation may increase late apoptosis in VILI. However, this study has limitations, including the need for experiments using other cell lines and validation through different experimental methods. Further investigation is needed to elucidate the underlying mechanisms of this injury pathway. This study underscores the importance of pressure regulation in mechanical ventilation to mitigate lung injury and improve patient outcomes.
