Divya D Nalayanda1, William B Fulton2, Paul M Colombani2, Tza-Huei Wang3, Fizan Abdullah4. 1. Division Pediatric Surgery, Johns Hopkins Medical Institutions, Baltimore MD; Department of Biomedical Engineering, Johns Hopkins University, Baltimore MD. 2. Division Pediatric Surgery, Johns Hopkins Medical Institutions, Baltimore MD. 3. Department of Biomedical Engineering, Johns Hopkins University, Baltimore MD; Department of Mechanical Engineering, Johns Hopkins University, Baltimore MD. 4. Division Pediatric Surgery, Johns Hopkins Medical Institutions, Baltimore MD. Electronic address: fa@jhmi.edu.
Abstract
PURPOSE: The lungs of infants born with congenital diaphragmatic hernia suffer from immaturity as well as the short and long term consequences of ventilator-induced lung injury, including chronic lung disease. Antenatal and postnatal steroids are among current strategies promoted to treat premature lungs and limit long term morbidity. Although studied in whole-animal models, insight into ventilator-induced injury at the alveolar-capillary interface as well as the benefits of steroids, remains limited. The present study utilizes a multi-fluidic in vitro model of the alveolar-interface to analyze membrane disruption from compressive aerodynamic forces in dexamethasone-treated cultures. METHODS: Human alveolar epithelial cell lines, H441 and A549, were cultured in a custom-built chamber under constant aerodynamic shear followed by introduction of pressure stimuli with and without dexamethasone (0.1μM). On-chip bioelectrical measurements were noted to track changes to the cellular surface and live-dead assay to ascertain cellular viability. RESULTS: Pressure-exposed alveolar cultures demonstrated a significant drop in TEER that was less prominent with an underlying extracellular-matrix coating. Addition of dexamethasone resulted in increased alveolar layer integrity demonstrated by higher TEER values. Furthermore, dexamethasone-treated cells exhibited faster recovery, and the effects of pressure appeared to be mitigated in both cell types. CONCLUSION: Using a novel in vitro model of the alveolus, we demonstrate a dose-response relationship between pressure application and loss of alveolar layer integrity. This effect appears to be alleviated by dexamethasone and matrix sub-coating.
PURPOSE: The lungs of infants born with congenital diaphragmatic hernia suffer from immaturity as well as the short and long term consequences of ventilator-induced lung injury, including chronic lung disease. Antenatal and postnatal steroids are among current strategies promoted to treat premature lungs and limit long term morbidity. Although studied in whole-animal models, insight into ventilator-induced injury at the alveolar-capillary interface as well as the benefits of steroids, remains limited. The present study utilizes a multi-fluidic in vitro model of the alveolar-interface to analyze membrane disruption from compressive aerodynamic forces in dexamethasone-treated cultures. METHODS:Human alveolar epithelial cell lines, H441 and A549, were cultured in a custom-built chamber under constant aerodynamic shear followed by introduction of pressure stimuli with and without dexamethasone (0.1μM). On-chip bioelectrical measurements were noted to track changes to the cellular surface and live-dead assay to ascertain cellular viability. RESULTS: Pressure-exposed alveolar cultures demonstrated a significant drop in TEER that was less prominent with an underlying extracellular-matrix coating. Addition of dexamethasone resulted in increased alveolar layer integrity demonstrated by higher TEER values. Furthermore, dexamethasone-treated cells exhibited faster recovery, and the effects of pressure appeared to be mitigated in both cell types. CONCLUSION: Using a novel in vitro model of the alveolus, we demonstrate a dose-response relationship between pressure application and loss of alveolar layer integrity. This effect appears to be alleviated by dexamethasone and matrix sub-coating.
Authors: Cornelia Blume; Riccardo Reale; Marie Held; Timothy M Millar; Jane E Collins; Donna E Davies; Hywel Morgan; Emily J Swindle Journal: PLoS One Date: 2015-10-05 Impact factor: 3.240