miR-19b mediates lung epithelial-mesenchymal transition via PTEN signaling in response to mechanical stretch. Homo sapiens

Alveolar epithelial type II (AEII) cells are the first line host in response to mechanical ventilation. We tested the hypothesis that the modulation of microRNA on AEII cells in response to mechanical stretch may participate in the ventilator-induced lung injury. This experiment is designed to screen miRNAs that are deregulated during mechanical stretch of AEII cells. Overall design: primary human AEII cells were isolated from distal portions of normal lung tissues of three oncologic patients undergoing lung resection and characterized by the expression pro-SP-C, α-ENac and Green DND-26 staining. AEII cells were seeded into BioFlex Culture 6-well plates (Flexcell International Corporation, Hillsborough, NC) at a density 5×10^5 cells/well in small airway cell growth medium (SAGM, Lonza, Walkersville, MD) containing 1% FBS for 24 h. The cells were then subjected to cyclic stretch for 48 h at a frequency of 20 cycles/min and 20% elongation (FX-5000; Flexcell International Corporation, Hillsborough, NC). Static resting cells served as controls. After mechanical stretch, Stretched and static AEII were subjected to miRNA array (Exiqon miRCURY™ LNA Array v.18.0) analysis.