title: Carbon black nanoparticles induce biphasic gene expression changes associated with inflammatory responses in the lungs of C57BL/6 mice following a single intratracheal instillation.
abstract: Inhalation of carbon black nanoparticles (CBNPs) causes pulmonary inflammation; however, time course data to evaluate the detailed evolution of lung inflammatory responses are lacking. Here we establish a time-series of lung inflammatory response to CBNPs. Female C57BL/6 mice were intratracheally instilled with 162 μg CBNPs alongside vehicle controls. Lung tissues were examined 3h, and 1, 2, 3, 4, 5, 14, and 42 days (d) post-exposure. Global gene expression and pulmonary inflammation were assessed. DNA damage was evaluated in bronchoalveolar lavage (BAL) cells and lung tissue using the comet assay. Increased neutrophil influx was observed at all time-points. DNA strand breaks were increased in BAL cells 3h post-exposure, and in lung tissues 2-5d post-exposure. Approximately 2600 genes were differentially expressed (± 1.5 fold; p ≤ 0.05) across all time-points in the lungs of exposed mice. Altered transcript levels were associated with immune-inflammatory response and acute phase response pathways, consistent with the BAL profiles and expression changes found in common respiratory infectious diseases. Genes involved in DNA repair, apoptosis, cell cycle regulation, and muscle contraction were also differentially expressed. Gene expression changes associated with inflammatory response followed a biphasic pattern, with initial changes at 3h post-exposure declining to base-levels by 3d, increasing again at 14 d, and then persisting to 42 d post-exposure. Thus, this single CBNP exposure that was equivalent to nine 8-h working days at the current Danish occupational exposure limit induced biphasic inflammatory response in gene expression that lasted until 42 d post-exposure, raising concern over the chronic effects of CBNP exposure.
authors.affiliation: Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, ON, Canada. Electronic address: mainul.husain@hc-sc.gc.ca.
authors.forename: Mainul
authors.initials: M
authors.lastname: Husain
authors.affiliation: National Research Centre for the Working Environment, Copenhagen, Denmark. Electronic address: zky@nrcwe.dk.
authors.forename: Zdenka O
authors.initials: ZO
authors.lastname: Kyjovska
authors.affiliation: Water and Air Quality Bureau, Safe Environments Directorate, HECSB, Health Canada, Ottawa, ON, Canada. Electronic address: julie.bourdon-lacombe@hc-sc.gc.ca.
authors.forename: Julie
authors.initials: J
authors.lastname: Bourdon-Lacombe
authors.affiliation: National Research Centre for the Working Environment, Copenhagen, Denmark. Electronic address: ats@nrcwe.dk.
authors.forename: Anne T
authors.initials: AT
authors.lastname: Saber
authors.affiliation: National Research Centre for the Working Environment, Copenhagen, Denmark. Electronic address: kaj@arbejdsmiljoforskning.dk.
authors.forename: Keld A
authors.initials: KA
authors.lastname: Jensen
authors.affiliation: National Research Centre for the Working Environment, Copenhagen, Denmark. Electronic address: nrj@nrcwe.dk.
authors.forename: Nicklas R
authors.initials: NR
authors.lastname: Jacobsen
authors.affiliation: Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, ON, Canada. Electronic address: andrew.williams@hc-sc.gc.ca.
authors.forename: Andrew
authors.initials: A
authors.lastname: Williams
authors.affiliation: National Research Centre for the Working Environment, Copenhagen, Denmark; Institute of Public Health, University of Copenhagen, Denmark. Electronic address: hwa@nrcwe.dk.
authors.forename: Håkan
authors.initials: H
authors.lastname: Wallin
authors.affiliation: Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, ON, Canada. Electronic address: sabina.halappanavar@hc-sc.gc.ca.
authors.forename: Sabina
authors.initials: S
authors.lastname: Halappanavar
authors.affiliation: National Research Centre for the Working Environment, Copenhagen, Denmark; Institute of Micro- and Nanotechnology, Technical University of Denmark, Lyngby, Denmark. Electronic address: ubv@nrcwe.dk.
authors.forename: Ulla
authors.initials: U
authors.lastname: Vogel
authors.affiliation: Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, ON, Canada. Electronic address: carole.yauk@hc-sc.gc.ca.
authors.forename: Carole L
authors.initials: CL
authors.lastname: Yauk
mesh_terms: D000280:Administration, Inhalation; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D002453:Cell Cycle / Q000187:drug effects / Q000235:genetics; D004249:DNA Damage / Q000187:drug effects / Q000235:genetics; D004260:DNA Repair / Q000187:drug effects / Q000235:genetics; D005260:Female; D015870:Gene Expression / Q000187:drug effects*; D008168:Lung / Q000187:drug effects*; D051379:Mice; D008810:Mice, Inbred C57BL; D053758:Nanoparticles / Q000009:adverse effects*; D016273:Occupational Exposure / Q000009:adverse effects; D011014:Pneumonia / Q000139:chemically induced* / Q000235:genetics; D053260:Soot / Q000009:adverse effects*; D014132:Trachea / Q000187:drug effects*
chemical_list: D053260:Soot
keywords: Biphasic response; Carbon black nanoparticles; Cell cycle regulation; DNA repair; Inflammation; Muscle contraction