title: Assessing the in vitro toxicity of the lunar dust environment  using respiratory cells exposed to Al(2)O(3) or SiO(2)  fine dust particles.
abstract: Prior chemical and physical analysis of lunar soil suggests a composition of dust particles that may contribute to the development of acute and chronic respiratory disorders. In this study, fine Al(2)O(3) (0.7 μm) and fine SiO(2) (mean 1.6 μm) were used to assess the cellular uptake and cellular toxicity of lunar dust particle analogs. Respiratory cells, murine alveolar macrophages (RAW 264.7) and human type II epithelial (A549), were cultured as the in vitro model system. The phagocytic activity of both cell types using ultrafine (0.1 μm) and fine (0.5 μm) fluorescent polystyrene beads was determined. Following a 6-h exposure, RAW 264.7 cells had extended pseudopods with beads localized in the cytoplasmic region of cells. After 24 h, the macrophage cells were rounded and clumped and lacked pseudopods, which suggest impairment of phagocytosis. A549 cells did not contain beads, and after 24 h, the majority of the beads appeared to primarily coat the surface of the cells. Next, we investigated the cellular response to fine SiO(2) and Al(2)O(3) (up to 5 mg/ml). RAW 264.7 cells exposed to 1.0 mg/ml of fine SiO(2) for 6 h demonstrated pseudopods, cellular damage, apoptosis, and necrosis. A549 cells showed slight toxicity when exposed to fine SiO(2) for the same time and dose. A549 cells had particles clustered on the surface of the cells. Only a higher dose (5.0 mg/ml) of fine SiO(2) resulted in a significant cytotoxicity to A549 cells. Most importantly, both cell types showed minimal cytotoxicity following exposure to fine Al(2)O(3). Overall, this study suggests differential cellular toxicity associated with exposure to fine mineral dust particles.
authors.affiliation: Department of Natural Sciences, Clayton State University, Morrow, GA 30281, USA. jacquelinejordan@clayton.edu
authors.forename: Jacqueline A
authors.initials: JA
authors.lastname: Jordan
authors.forename: Ashley M
authors.initials: AM
authors.lastname: Verhoff
authors.forename: Julie E
authors.initials: JE
authors.lastname: Morgan
authors.forename: David G
authors.initials: DG
authors.lastname: Fischer
mesh_terms: D000537:Aluminum Oxide / Q000633:toxicity*; D017209:Apoptosis / Q000187:drug effects; D002478:Cells, Cultured; D005118:Extraterrestrial Environment / Q000737:chemistry; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008863:Microspheres; D016081:Moon; D010316:Particle Size; D010587:Phagocytosis; D011650:Pulmonary Alveoli / Q000166:cytology; D012822:Silicon Dioxide / Q000633:toxicity*; D018675:Toxicity Tests; D014481:United States; D018557:United States National Aeronautics and Space Administration
chemical_list: D012822:Silicon Dioxide; D007770:L-Lactate Dehydrogenase; D000537:Aluminum Oxide
references.citation: Respir Res. 2001;2(1):33-46
references.pmid: 11686863
references.citation: Part Fibre Toxicol. 2005 Oct 06;2:8
references.pmid: 16209704
references.citation: Environ Health Perspect. 2000 Aug;108 Suppl 4:675-84
references.pmid: 10931786
references.citation: Environ Health Perspect. 1997 Jul;105(7):706-11
references.pmid: 9294716
references.citation: Chem Res Toxicol. 2002 Sep;15(9):1166-73
references.pmid: 12230410
references.citation: Am J Respir Cell Mol Biol. 1998 May;18(5):687-95
references.pmid: 9569239
references.citation: Arch Toxicol. 2007 May;81(5):385-7
references.pmid: 17262219
references.citation: Occup Environ Med. 2004 May;61(5):442-7
references.pmid: 15090666
references.citation: Environ Res. 2004 Sep;96(1):62-71
references.pmid: 15261785
references.citation: Am J Respir Cell Mol Biol. 2002 Jul;27(1):91-8
references.pmid: 12091251
references.citation: Am J Respir Cell Mol Biol. 1998 Sep;19(3):426-36
references.pmid: 9730870
references.citation: Toxicol Sci. 2007 May;97(1):163-80
references.pmid: 17301066
references.citation: Mol Pharmacol. 1998 Mar;53(3):415-21
references.pmid: 9495806
references.citation: Environ Health Perspect. 1997 Sep;105 Suppl 5:1159-64
references.pmid: 9400717
references.citation: Am J Pathol. 1996 Nov;149(5):1627-37
references.pmid: 8909252
references.citation: J Immunol. 1999 Nov 15;163(10):5582-91
references.pmid: 10553087
references.citation: Am J Respir Cell Mol Biol. 2001 Feb;24(2):108-15
references.pmid: 11159043
references.citation: Environ Health Perspect. 2005 Nov;113(11):1555-60
references.pmid: 16263511
references.citation: Occup Environ Med. 2001 Mar;58(3):211-6, 199
references.pmid: 11171936
references.citation: Environ Health Perspect. 1997 Sep;105 Suppl 5:1013-20
references.pmid: 9400693
references.citation: Am J Respir Cell Mol Biol. 1999 Apr;20(4):631-42
references.pmid: 10100994
references.citation: Am Rev Respir Dis. 1984 Nov;130(5):778-82
references.pmid: 6093654
references.citation: Am J Respir Cell Mol Biol. 1990 Apr;2(4):381-90
references.pmid: 2157474
references.citation: Am J Pathol. 1998 Dec;153(6):1873-84
references.pmid: 9846977
references.citation: J Nanobiotechnology. 2004 Dec 08;2(1):12
references.pmid: 15588280
references.citation: Fundam Appl Toxicol. 1988 Apr;10(3):369-84
references.pmid: 3286345
references.citation: Environ Health Perspect. 2005 Jul;113(7):823-39
references.pmid: 16002369
references.citation: Environ Health Perspect. 1994 Dec;102 Suppl 10:149-54
references.pmid: 7705289
references.citation: Inhal Toxicol. 2002 Sep;14(9):901-16
references.pmid: 12396402
references.citation: Toxicol Sci. 2004 Jul;80(1):34-48
references.pmid: 15056807
references.citation: Exp Lung Res. 1990 Mar-Apr;16(2):83-99
references.pmid: 2328713
references.citation: Environ Health Perspect. 1997 Sep;105 Suppl 5:1139-42
references.pmid: 9400713
references.citation: Environ Health Perspect. 1974 Aug;8:3-95
references.pmid: 4470920
references.citation: Inhal Toxicol. 2002 Sep;14(9):917-28
references.pmid: 12396403
references.citation: Mol Cancer Res. 2005 Jul;3(7):373-9
references.pmid: 16046548
references.citation: Toxicol Appl Pharmacol. 1990 Feb;102(2):268-81
references.pmid: 2154066
references.citation: Am J Respir Cell Mol Biol. 2003 Aug;29(2):180-7
references.pmid: 12600817
references.citation: Toxicol Sci. 2006 Jan;89(1):42-50
references.pmid: 16177233