Effect of diesel exhaust particles on human middle ear epithelial cells.
OBJECTIVE
In the present study, we investigate whether diesel exhaust particles (DEPs) cause cytotoxicity and induce inflammation or increase the expression of mucin in immortalized human middle ear epithelial cell lines (HMEECs). Several publications have shown an association between traffic-related air pollutants and otitis media. Additionally, DEP have been shown to cause inflammation and an allergic response in the airways.


METHODS
Cell viability following DEP treatment was investigated in HMEECs using the MTT assay. We measured the expression of the inflammatory cytokines TNF-α and COX-2 and the mucin genes MUC5AC and MUC5B using semiquantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blotting.


RESULTS
Cell viability tests showed that exposure to more than 80 μg/mL of DEP caused a decrease in cell viability. DEP exposure also increased the expression of MUC5AC, but did not induce the expression of MUC5B in HMEECs.


CONCLUSIONS
DEP decreased cell viability, induced an inflammatory response, and increased mucin gene expression in HMEECs. These findings support the hypothesis that environmental diesel exposure is a risk factor for otitis media.
Department of Otolaryngology-Head and Neck Surgery, Dongguk University Ilsan Hospital, Ilsan, Republic of Korea.
Jae-Jun
JJ
Song
Jong Dae
JD
Lee
Byung Don
BD
Lee
Sung Won
SW
Chae
Moo Kyun
MK
Park
D000393:Air Pollutants / Q000494:pharmacology*; D018929:Cell Culture Techniques; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D051546:Cyclooxygenase 2 / Q000378:metabolism; D004432:Ear, Middle / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology*; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D055271:Mucin 5AC / Q000378:metabolism; D055257:Mucin-5B / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D001335:Vehicle Emissions / Q000633:toxicity*
D000393:Air Pollutants; C524678:MUC5AC protein, human; C524578:MUC5B protein, human; D055271:Mucin 5AC; D055257:Mucin-5B; D014409:Tumor Necrosis Factor-alpha; D001335:Vehicle Emissions; D051546:Cyclooxygenase 2