title: Gene-expression profiling using suppression-subtractive hybridization and cDNA microarray in rat mononuclear cells in response to welding-fume exposure.
abstract: Welders with radiographic pneumoconiosis abnormalities have shown a gradual clearing of the X-ray identified effects following removal from exposure. In some cases, the pulmonary fibrosis associated with welding fumes appears in a more severe form in welders. Accordingly, for the early detection of welding-fume-exposure-induced pulmonary fibrosis, the gene expression profiles of peripheral mononuclear cells from rats exposed to welding fumes were studied using suppression-subtractive hybridization (SSH) and a cDNA microarray. As such, Sprague-Dawley rats were exposed to a stainless steel arc welding fume for 2 h/day in an inhalation chamber with a 1107.5 +/- 2.6 mg/m3 concentration of total suspended particulate (TSP) for 30 days. Thereafter, the total RNA was extracted from the peripheral blood mononuclear cells, the cDNA synthesized from the total RNA using the SMART PCR cDNA method, and SSH performed to select the welding-fume-exposure-regulated genes. The cDNAs identified by the SSH were then cloned into a plasmid miniprep, sequenced and the sequences analysed using the NCBI BLAST programme. In the SSH cloned cDNA microarray analysis, five genes were found to increase their expression by 1.9-fold or more, including Rgs 14, which plays an important function in cellular signal transduction pathways; meanwhile 36 genes remained the same and 30 genes decreased their expression by more than 59%, including genes associated with the immune response, transcription factors and tyrosine kinases. Among the 5200 genes analysed, 256 genes (5.1%) were found to increase their gene expression, while 742 genes (15%) decreased their gene expression in response to the welding-fume exposure when tested using a commercial 5.0k DNA microarray. Therefore, unlike exposure to other toxic substances, prolonged welding-fume exposure was found to substantially downregulate many genes.
authors.affiliation: Center for Occupational Toxicology, Occupational Safety & Health Research Institute, KOSHA, Daejeon, Republic of Korea.
authors.forename: Kyung Taek
authors.initials: KT
authors.lastname: Rim
authors.forename: Kun Koo
authors.initials: KK
authors.lastname: Park
authors.forename: Jae Hyuck
authors.initials: JH
authors.lastname: Sung
authors.forename: Yong Hyun
authors.initials: YH
authors.lastname: Chung
authors.forename: Jeong Hee
authors.initials: JH
authors.lastname: Han
authors.forename: Key Seung
authors.initials: KS
authors.lastname: Cho
authors.forename: Kwang Jong
authors.initials: KJ
authors.lastname: Kim
authors.forename: Il Je
authors.initials: IJ
authors.lastname: Yu
mesh_terms: D000395:Air Pollutants, Occupational / Q000633:toxicity*; D000818:Animals; D004195:Disease Models, Animal; D015536:Down-Regulation; D005740:Gases / Q000737:chemistry / Q000633:toxicity; D015870:Gene Expression / Q000187:drug effects*; D020869:Gene Expression Profiling; D019570:Inhalation Exposure; D007963:Leukocytes, Mononuclear / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D011658:Pulmonary Fibrosis / Q000097:blood / Q000139:chemically induced / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013047:Specific Pathogen-Free Organisms; D013193:Stainless Steel / Q000633:toxicity*; D014896:Welding
chemical_list: D000395:Air Pollutants, Occupational; D005740:Gases; D012333:RNA, Messenger; D013193:Stainless Steel