title: Intracellular storage of surfactant and proinflammatory cytokines in co-cultured alveolar epithelium and macrophages in response to increasing CO2 and cyclic cell stretch.
abstract: Cell stretch stimulates both surfactant and cytokine production. The authors proposed that stretch, through these effects, modifies the pathogenesis of lipopolysaccharide-induced acute lung injury (ALI), and that this is CO(2) dependent. Rat alveolar type II cells and macrophages were co-cultured with lipopolysaccharide in 5%, 10%, or 20% CO(2) +/- stretch (30%, 60 cycles/min) for 6 hours. Intracellular TNF-alpha and IL-6 increased whereas secreted cytokine and surfactant decreased with increasing CO(2). Stretch independently increased intracellular TNF-alpha and decreased IL-6 secretion. Elevated CO(2) may therefore diminish secretion of proinflammatory cytokines by alveolar cells, contributing to an explanation for protective hypercapnia in ALI.
authors.affiliation: Department of Critical Care Medicine, Flinders University, Adelaide, SA 5006, Australia. dani.bryan@flinders.edu.au
authors.forename: Dani-Louise
authors.initials: DL
authors.lastname: Dixon
authors.forename: Heather A
authors.initials: HA
authors.lastname: Barr
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Bersten
authors.forename: Ian R
authors.initials: IR
authors.lastname: Doyle
mesh_terms: D000818:Animals; D002245:Carbon Dioxide / Q000494:pharmacology*; D002453:Cell Cycle; D018920:Coculture Techniques; D016207:Cytokines / Q000096:biosynthesis / Q000378:metabolism*; D004847:Epithelial Cells; D007249:Inflammation; D015850:Interleukin-6 / Q000096:biosynthesis / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D016676:Macrophages, Alveolar / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D011650:Pulmonary Alveoli / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D011663:Pulmonary Surfactants / Q000378:metabolism*; D051381:Rats; D012128:Respiratory Distress Syndrome / Q000209:etiology; D013314:Stress, Mechanical; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000378:metabolism
chemical_list: D016207:Cytokines; D015850:Interleukin-6; D008070:Lipopolysaccharides; D011663:Pulmonary Surfactants; D014409:Tumor Necrosis Factor-alpha; D002245:Carbon Dioxide