title: Effects of lipopolysaccharide, multiwalled carbon nantoubes, and the combination on lung alveolar epithelial cells.
abstract: Multiwalled carbon nanotubes (MWCNT) have been shown to induce lung fibrosis in animal models, however the underlying molecular factors/mechanisms are still unclear. In this study, we investigated the effects of lipopolysaccharide (LPS), MWCNT, and the combination of LPS and MWCNT on the expression of matrix metalloproteinase-9 and metalloproteinase-12 (MMP-9, MMP-12), collagen 3A1 (Col3A1), and transforming growth factor beta (TGFβ) in alveolar epithelial A549 cells. MMPs are proteinases that degrade extracellular matrix and play a role in lung fibrosis. A549 cells were exposed to LPS (1 ng/mL), MWCNT (20 μg/mL), and the combination and analyzed for paracellular permeability, TGFβ, Col3A1, MMP-9, MMP-12, NF-κB activation, and cell migration by real-time PCR and immunofluorescence. LPS, the combination of LPS and MWCNT, and MWCNT only at the highest tested dose induced blue dextran extravasation. LPS and MWCNT increased the expression of TGFβ and its downstream target gene Col3A, and MMP-9 and MMP-12 mRNA. MWCNT potently induced cell migration toward wound healing, whereas LPS slightly induced cell migration. Both, LPS and MWCNT, induced NF-κB nuclear translocation. Our results indicate that MWCNT activated alveolar epithelial cells to promote fibrogenesis, and that LPS differentially primes molecular factors involved in lung remodeling. These findings suggest a role of alveolar epithelial cells in fibrogenesis and also may aid in the design and development of tests for screening of fibrogenic agents. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 445-455, 2017.
authors.affiliation: Biology Department, College of Science, Engineering, and Technology, Jackson State University, Jackson, MS, 39217.|NIH RCMI-Center for Environmental Health, College of Science, Engineering, and Technology, Jackson State University, Jackson, MS, 39217.
authors.forename: M
authors.initials: M
authors.lastname: Pacurari
authors.affiliation: University of Mississippi Medical Center, Jackson, MS, 39216.
authors.forename: I
authors.initials: I
authors.lastname: May
authors.affiliation: Biology Department, College of Science, Engineering, and Technology, Jackson State University, Jackson, MS, 39217.|NIH RCMI-Center for Environmental Health, College of Science, Engineering, and Technology, Jackson State University, Jackson, MS, 39217.
authors.forename: P B
authors.initials: PB
authors.lastname: Tchounwou
mesh_terms: D056809:Alveolar Epithelial Cells / Q000187:drug effects*; D002460:Cell Line; D002463:Cell Membrane Permeability / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D024061:Collagen Type III / Q000378:metabolism; D006801:Humans; D008070:Lipopolysaccharides / Q000633:toxicity*; D020782:Matrix Metalloproteinases / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D037742:Nanotubes, Carbon / Q000633:toxicity*; D015398:Signal Transduction; D016212:Transforming Growth Factor beta / Q000096:biosynthesis; D014945:Wound Healing / Q000187:drug effects
chemical_list: D024061:Collagen Type III; D008070:Lipopolysaccharides; D016328:NF-kappa B; D037742:Nanotubes, Carbon; D016212:Transforming Growth Factor beta; D020782:Matrix Metalloproteinases
keywords: ECM; LPS; MMP-12; MMP-9; MWCNT; NF-κB; TGFβ; alveolar epithelial cells; cell migration; collagen