Gene expression analysis in induced sputum from welders with and without airway-related symptoms.
OBJECTIVE
To identify changes in gene expression in the airways among welders, with and without lower airway symptoms, working in black steel.


METHODS
Included were 25 male, non-smoking welders. Each welder was sampled twice; before exposure (after vacation), and after 1 month of exposure. From the welders (14 symptomatic, of whom 7 had asthma-like symptoms), RNA from induced sputum was obtained for gene expression analysis. Messenger RNA from a subset of the samples (n = 7) was analysed with microarray technology to identify genes of interest. These genes were further analysed using quantitative PCR (qPCR; n = 22).


RESULTS
By comparing samples before and after exposure, the microarray analysis resulted in several functional annotation clusters: the one with the highest enrichment score contained "response to wounding", "inflammatory response" and "defence response". Seven genes were analysed by qPCR: granulocyte colony-stimulating factor 3 receptor (CSF3R), superoxide dismutase 2, interleukin 8, glutathione S-transferase pi 1, tumour necrosis factor alpha-induced protein 6 (TNFAIP6), interleukin 1 receptor type II and matrix metallopeptidase 25 (MMP25). Increased levels of CSF3R, TNFAIP6 and MMP25 were indicated among asthmatic subjects compared to non-symptomatic subjects, although the differences did not reach significance.


CONCLUSIONS
Workers' exposure to welding fumes changed gene expression in the lower airways in genes involved in inflammatory and defence response. Thus, microarray and qPCR technique can demonstrate markers of exposure to welding fumes and possible disease-related markers. However, further studies are needed to verify genes involved and to further characterise the mechanism for welding fumes-associated lower airway symptoms.
Jönsson
Lena S
LS
Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University Hospital, 221 85, Lund, Sweden.
Nielsen
Jørn
J
Broberg
Karin
K
D000328:Adult; D015870:Gene Expression / Q000235:genetics*; D006801:Humans; D007249:Inflammation / Q000235:genetics; D008297:Male; D046228:Microarray Analysis; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects*; D018384:Oxidative Stress; D016133:Polymerase Chain Reaction; D012131:Respiratory Insufficiency / Q000453:epidemiology / Q000209:etiology / Q000235:genetics*; D013183:Sputum; D013548:Sweden; D014896:Welding; D055815:Young Adult