Transfection of Sox11 plasmid alleviates ventilator-induced lung injury via Sox11 and FAK

Ventilator-induced lung-injury in mouse models: Is there a trap?

Ventilator-induced lung injury (VILI) is a serious acute injury to the lung tissue that can develop during mechanical ventilation of patients. Due to the mechanical strain of ventilation, damage can occur in the bronchiolar and alveolar epithelium resulting in a cascade of events that may be fatal to the patients. Patients requiring mechanical ventilation are often critically ill, which limits the possibility of obtaining patient samples, making VILI research challenging. In vitro models are very important for VILI research, but the complexity of the cellular interactions in multi-organ animals, necessitates in vivo studies where the mouse model is a common choice. However, the settings and duration of ventilation used to create VILI in mice vary greatly, causing uncertainty in interpretation and comparison of results. This review examines approaches to induce VILI in mouse models for the last 10 years, to our best knowledge, summarizing methods and key parameters presented across the studies. The results imply that a more standardized approach is warranted.

Enhancement of FAK alleviates ventilator-induced alveolar epithelial cell injury

Mechanical ventilation induces lung injury by damaging alveolar epithelial cells (AECs), but the pathogenesis remains unknown. Focal adhesion kinase (FAK) is a cytoplasmic protein tyrosine kinase that is involved in cell growth and intracellular signal transduction pathways. This study explored the potential role of FAK in AECs during lung injury induced by mechanical ventilation. High-volume mechanical ventilation (HMV) was used to create a mouse lung injury model, which was validated by analysis of lung weight, bronchoalveolar lavage fluid and histological investigation. The expression of FAK and Akt in AECs were evaluated. In addition, recombinant FAK was administered to mice via the tail vein, and then the extent of lung injury was assessed. Mouse AECs were cultured in vitro, and FAK expression in cells under stretch was investigated. The effects of FAK on cell proliferation, migration and apoptosis were investigated. The results showed that HMV decreased FAK expression in AECs of mice, while FAK supplementation attenuated lung injury, reduced protein levels/cell counts in the bronchoalveolar lavage fluid and decreased histological lung injury and oedema. The protective effect of FAK promoted AEC proliferation and migration and prevented cells from undergoing apoptosis, which restored the integrity of the alveoli through Akt pathway. Therefore, the decrease in FAK expression by HMV is essential for injury to epithelial cells and the disruption of alveolar integrity. FAK supplementation can reduce AEC injury associated with HMV.