Asian Sand Dust Enhances the Inflammatory Response and Mucin Gene Expression in the Middle Ear.
OBJECTIVE
Asia sand dust (ASD) is known to cause various human diseases including respiratory infection. The aim of this study was to examine the effect of ASD on inflammatory response in human middle ear epithelial cells (HMEECs) in vitro and in vivo.


METHODS
Cell viability was assessed using the cell counting kit-8 assay. The mRNA levels of various genes including COX-2, TNF-a, MUC 5AC, MUC 5B, TP53, BAX, BCL-2, NOX4, and SOD1 were analyzed using semiquantitative realtime polymerase chain reaction. COX-2 protein levels were determined by western blot analysis. Sprague Dawley rats were used for in vivo investigations of inflammatory reactions in the middle ear epithelium as a result of ASD injection.


RESULTS
We observed dose-dependent decrease in HMEEC viability. ASD exposure significantly increased COX-2, TNF-a, MUC5AC, and MUC5B mRNA expression. Also, ASD affected the mRNA levels of apoptosis- and oxidative stress-related genes. Western blot analysis revealed a dose-dependent increase in COX-2 production. Animal studies also demonstrated an ASD-induced inflammatory response in the middle ear epithelium.


CONCLUSIONS
Environmental ASD exposure can result in the development of otitis media.
Department of Otolaryngology-Head and Neck Surgery, Hallym University College of Medicine, Seoul, Korea.
Jiwon
J
Chang
Department of Otorhinolaryngology-Head and Neck Surgery, Korea University College of Medicine, Seoul, Korea.
Yoon Young
YY
Go
Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University College of Medicine, Seoul, Korea.
Moo Kyun
MK
Park
Department of Otorhinolaryngology-Head and Neck Surgery, Korea University College of Medicine, Seoul, Korea.
Sung-Won
SW
Chae
Department of Nursing Science, College of Nursing, Gachon University, Incheon, Korea.
Seon-Heui
SH
Lee
Department of Otorhinolaryngology-Head and Neck Surgery, Korea University College of Medicine, Seoul, Korea.
Jae-Jun
JJ
Song
Asian Sand Dust; Cyclooxygenase 2; Muc5ac; Muc5b; Otitis Media