Distinct Regulatory Profiles of Interleukins and Chemokines in Response to Cigarette Smoke Condensate in Normal Human Bronchial Epithelial (NHBE) Cells

Abstract

Bronchial epithelium is frequently exposed to air pollutants, and it is hypothesized that these cells elicit inflammatory responses as early elements in pulmonary defense. Our purpose was to evaluate changes in messenger RNA levels of 84 genes representing cytokines and receptors over a repetitive-exposure time course to further define the inflammatory responses associated with mainstream cigarette smoke (MSS) exposure in an in vitro lung model. Normal human bronchial epithelial cells were treated with mainstream cigarette smoke condensate (CSC) prepared from Kentucky 2R4F cigarettes (60 microg total particulate matter/mL media, 0.2% dimethylsulfoxide), and examined by quantitative real-time polymerase chain reaction. Applications of CSC were designed in seven groups to test immediate, early, intermediate, and late responses evaluated at the end of alternating exposure/recovery periods. Three predominant gene expression responses were observed: adaptive (return to baseline), sustained (maintained expression during treatment), and chronic (maintained expression posttreatment). Overall, 25 genes exhibited statistically significant changes: 14 genes exclusively elevated, 10 genes exclusively depressed, and 1, interleukin-8 (IL8), exhibiting both up- and downregulation in the seven groups. The most responsive genes were osteopontin (34-fold upregulation) and CXCL14 (23-fold downregulation). Our observations suggest that specific genes involved in inflammatory pathways respond to CSC in chronic, sustained, or adaptive patterns with the chronic pattern as the predominant behavior.

In vitro and clinical studies examining the expression of osteopontin in cigarette smoke-exposed endothelial cells and cigarette smokers

“…Here, we report that exposure of endothelial cells to cigarette smoke PM in vitro induced the expression of osteopontin, a previously undescribed effect which may have important implications for our understanding of the association of smoking with cardiovascular disease. While a similar effect has previously been reported in human bronchial epithelial cells [17], this is the first instance where osteopontin production has been reported in response to cigarette smoke exposure in endothelial cells. Thus, the endothelium is a potential source of smoke-induced inflammatory osteopontin protein and this may play a role in cardiovascular disease.…”

“…Cigarette smoke is both a source and a cause of the production of cellular reactive oxygen species. The pro-inflammatory effects of cigarette smoke have been well described [17-21] and these may occur through activation of oxidative stress-regulated transcription factors such as NFκB or AP-1, which regulate the expression levels of inflammatory mediators. Given our current data, we propose that endothelial-derived osteopontin may be a mediator of smoke- and oxidative stress-induced inflammation with a role in the development and/or progression of cardiovascular disease.…”

Interleukin-1 Family Member 9 Stimulates Chemokine Production and Neutrophil Influx in Mouse Lungs

“…Infection with rhinovirus also upregulated IL-1F9 mRNA expression in patients with asthma (23). Cigarette smoke condensate, tumor necrosis factor, IL-1b, IL-17, and double-stranded RNA are some of the other stimuli reported to increase mRNA expression in normal human bronchial epithelial cells (24,25).…”

Evaluation of cytotoxicity of different tobacco product preparations

“…Well-recognized cellular responses to smoke or smoke-constituent exposure include marked cytotoxicity and induction of inflammatory responses, as noted by increased secretion of IL8 and other proinflammatory cytokines Parsanejad et al, 2008). The chemokine IL8 mainly attracts neutrophils and lymphocytes and may result in neutrophilia (Goncalves et al, 2010;Kobayashi, 2008;Larsen et al, 1989;Tomita et al, 2003) and lymphocytosis (Jagels and Hugli, 1992;Terashima et al, 1998).…”