Cyclic stretch upregulates interleukin-8 and transforming growth factor-beta1 production through a protein kinase C-dependent pathway in alveolar epithelial cells.
OBJECTIVE
Positive-pressure mechanical ventilation can injure the lung, causing oedema and alveolar inflammation, which is termed 'ventilator-induced lung injury' (VILI). We postulated that cyclic stretch upregulates the release of cytokines, which may cause lung damage, and explored which cytokines were released after cyclic stretch in type II alveolar epithelial cells (A549).


METHODS
To test this hypothesis, A549 cells were cultured on a silicoelastic membrane and interleukin (IL)-1beta, IL-8, granulocyte-macrophage colony stimulating factor, activin, transforming growth factor (TGF)-beta1, insulin-like growth factor-2 and tumour necrosis factor-alpha mRNA and protein were assessed after stimulation of the cells by cyclic stretch.


RESULTS
Cyclic stretch induced activation of protein kinase C and resulted in the release of IL-8 and TGF-beta1 from A549 cells.


CONCLUSIONS
The release of IL-8 and TGF-beta1 from alveolar epithelial cells may be a contributing factor in alveolitis associated with VILI.
Yamamoto
Hiroyuki
H
Third Department of Internal Medicine, Faculty of Medicine, Tottori University, Yonago, Japan.
Teramoto
Hidemi
H
Uetani
Kohsaku
K
Igawa
Katsutoshi
K
Shimizu
Eiji
E
D015153:Blotting, Western; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000378:metabolism*; D006801:Humans; D016209:Interleukin-8 / Q000378:metabolism*; D011650:Pulmonary Alveoli / Q000166:cytology* / Q000378:metabolism* / Q000473:pathology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000502:physiology; D013314:Stress, Mechanical; D016212:Transforming Growth Factor beta / Q000378:metabolism*; D053773:Transforming Growth Factor beta1; D015854:Up-Regulation
D016209:Interleukin-8; C508960:TGFB1 protein, human; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1