Pattern changes of mucin gene expression with pneumococcal otitis media.
OBJECTIVE
mucins, known to be important components of the mucociliary transport system in the middle ear and Eustachian tube, are subject to changes under inflammatory conditions. Which mucin genes are up-regulated or activated during an inflammatory reaction of the middle ear and Eustachian tube, however, is poorly understood. The purpose of this study was to characterize mucin gene expression in middle ears and Eustachian tubes with pneumococcal ear infection.


METHODS
sixteen rats received intrabullar inoculation of Streptococcus pneumoniae type 6A at 2.5x10(6) colony forming units (CFU). Four animals were sacrificed on days 1, 3, 7, and 14, respectively. The profile of mucin gene expression in the middle ear and Eustachian tube was examined by reverse transcription polymerase chain reaction (RT-PCR) at the above time points. Sixteen rats that received intrabullar inoculation of phosphate-buffered saline (PBS) served as controls.


RESULTS
the Muc2 mucin gene was expressed in middle ear mucosa of the control rats. Following pneumococcal inoculation, Muc1-Muc5 mucin genes were expressed in the middle ear mucosa in a time-dependent manner. In the Eustachian tube, the Muc2, Muc4 and Muc5 mucin genes were expressed in both control and pneumococcal inoculation groups.


CONCLUSIONS
Muc1, Muc3, Muc4, and Muc5 mucin genes were activated in the middle ear mucosa by pneumococci, which may contribute to hyper-production of mucin in acute pneumococcal otitis media.
Tsuboi
Y
Y
Otitis Media Research Center, Department of Otolaryngology, School of Medicine, University of Minnesota, 2001 Sixth Street S.E., Rm. 216, Minneapolis, MN 55455, USA. tsubo001@tc.umn.edu
Kim
Y
Y
Paparella
M M
MM
Chen
N
N
Schachern
P A
PA
Lin
J
J
D000818:Animals; D004432:Ear, Middle / Q000378:metabolism; D005064:Eustachian Tube / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D023421:Models, Animal; D009077:Mucins / Q000235:genetics*; D010034:Otitis Media with Effusion / Q000235:genetics* / Q000378:metabolism; D011008:Pneumococcal Infections / Q000235:genetics* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013296:Streptococcus pneumoniae / Q000235:genetics*; D015854:Up-Regulation
D009077:Mucins