Diesel Exhaust Particles Upregulate Interleukins IL-6 and IL-8 in Nasal Fibroblasts.
BACKGROUND
Diesel exhaust particles (DEP) are a major source of air pollution. Nasal fibroblasts are known to produce various cytokines and chemokines. The aim of this study was to evaluate DEP-induced cytokines and chemokines in nasal fibroblasts and to identify the signaling pathway involved.


METHODS
A cytokine and chemokine array performed after stimulation of nasal fibroblasts with DEP revealed that levels of IL-6 and IL-8 were increased most significantly among various cytokines and chemokines. RT-PCR and ELISA were used to determine the mRNA and protein expression levels of IL-6 and IL-8. Signaling pathways of p-38, Akt, and NF-κB were analyzed by western blotting, luciferase assay, and ELISA. Organ cultures of nasal interior turbinate were also developed to demonstrate the ex vivo effect of DEP on the expression of IL-6 and IL-8 and the associated signaling pathway.


RESULTS
DEP increased the expressions of IL-6 and IL-8 in nasal fibroblasts at mRNA and protein levels. DEP induced phosphorylation of p38, Akt, and NF-κB, whereas inhibitors of p38, Akt, and NF-κB blocked these phophorylations and the expressions of IL-6 and IL-8. These findings were also observed in ex vivo organ culture of nasal inferior turbinate.


CONCLUSIONS
DEP induces expression of IL-6 and IL-8 via p38, Akt, and NF-κB signaling pathways in nasal fibroblasts. This finding suggests that air pollution might induce or aggravate allergic rhinitis or chronic rhinosinusitis.
Biomedical Science, Korea University, College of Medicine, Seoul, Korea.
Jin Ah
JA
Kim
Department of Otorhinolaryngology-Head and Neck Surgery, College of Medicine, Konkuk University, Seoul, Korea.
Jae Hoon
JH
Cho
Department of Otorhinolaryngology-Head and Neck Surgery, Korea University, College of Medicine, Seoul, Korea.
Il-Ho
IH
Park
Department of Otorhinolaryngology-Head and Neck Surgery, Korea University, College of Medicine, Seoul, Korea.
Jae-Min
JM
Shin
Institute for Medical Devices Clinical Trial Center, Guro Hospital, Seoul, Korea.
Seoung-Ae
SA
Lee
Biomedical Science, Korea University, College of Medicine, Seoul, Korea.|Department of Otorhinolaryngology-Head and Neck Surgery, Korea University, College of Medicine, Seoul, Korea.|Institute for Medical Devices Clinical Trial Center, Guro Hospital, Seoul, Korea.
Heung-Man
HM
Lee
D000328:Adult; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism; D005260:Female; D005347:Fibroblasts / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism*; D016209:Interleukin-8 / Q000378:metabolism*; D008297:Male; D009297:Nasal Mucosa / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D052638:Particulate Matter / Q000494:pharmacology*; D015398:Signal Transduction; D015854:Up-Regulation / Q000187:drug effects; D001335:Vehicle Emissions / Q000633:toxicity
D015850:Interleukin-6; D016209:Interleukin-8; D052638:Particulate Matter; D001335:Vehicle Emissions