Project description:Children have a lower incidence and mortality from acute lung injury than adults, and infections are the most common event associated with acute lung injury (ALI). To study the effects of age on susceptibility to ALI, we investigated the responses to microbial products combined with mechanical ventilation in juvenile (21 day) and adult (16 week-old) mice. We hypothesized that the increased incidence and severity of lung injury associated with increasing age is due in large part to acquired changes in the way in which inflammatory responses are activated in the lungs in response to microbial products and mechanical ventilation. Juvenile (21 day) and adult (16 week) C57BL/6 mice were treated with an aerosol of E. coli 0111:B4 lipopolysaccharide (LPS) (20 mL of 0.1 mg/mL) for 30 minutes in a sealed aerosol chamber, immediately followed by mechanical ventilation (LPS+MV) using tidal volume = 15 mL/kg, rate = 80 breaths/min, FiO2 = 30% and positive end expiratory pressure = 2 cm H2O for the duration of the study period time = 2 hours. Comparison groups included mice treated with LPS or mechanical ventilation (MV) alone, and untreated age-matched controls. There were N = 4 animals per group except the juvenile mice treated with MV alone and LPS+MV where there were N = 3. Each sample was an individual animal, therefore there were 30 samples. Mice treated with LPS alone were placed into a sealed aerosol chamber as stated above, and then allowed to breath spontaneously with free access to food and water for the duration of the study period time = 2 hours. Mice treated with MV alone were treated with the mechanical ventilation protocol stated above for the duration of the study period time = 2 hours. At the end of the study period, the mice were euthanized, and the lungs were immediately removed and placed into RNAlater (Ambion, Austin, TX) for at least 24 hr prior to isolation of total lung mRNA.
Project description:Rat model of ARDS was induced by saline lavage and mechanical ventilation. miRNA from rat lungs were used for dual color DNA microarray hybridization with 3DNA 50 kit version 2. Two-condition experiment, CON vs. ARDS lung tissues. replicates: 6 control, 6 ARDS. One replicate per array.
Project description:Rat model of ARDS was induced by saline lavage and mechanical ventilation. Total RNA from rat lungs were used for dual color DNA microarray hybridization with 3DNA 50 kit version 2. Two-condition experiment, CON vs. ARDS lung tissues. replicates: 5 control, 7 ARDS. One replicate per array.
Project description:Cyclic stretch of alveoli is characteristic of mechanical ventilation, and is postulated to be partly responsible for the lung injury and inflammation in ventilator induced lung injury. We propose that miRNAs may regulate some of the stretch response and, therefore, hypothesized that miRNAs would be differentially expressed between stretched and unstretched rat alveolar epithelial cells (RAECs). RAECs were isolated and cultured to express type I epithelial characteristics, after which they were equibiaxially stretched to 25% change in surface area at 15 cycles/minute for 1 or 6 hrs, or served as unstretched controls, and miRNA were extracted (n = 4 for all groups).
Project description:Cyclic stretch of alveoli is characteristic of mechanical ventilation, and is postulated to be partly responsible for the lung injury and inflammation in ventilator induced lung injury. We propose that miRNAs may regulate some of the stretch response and, therefore, hypothesized that miRNAs would be differentially expressed between stretched and unstretched rat alveolar epithelial cells (RAECs).
Project description:In the present study we seek to identify changes in lung gene expression under mechanical ventilation in uninjured as well as acutely and chronically injured lungs. A standard volume-controlled lung-protective ventilatory protocol is compared to a concept of mechanical ventilation using variable tidal volumes.