Upregulation of MUC8 and downregulation of MUC5AC by inflammatory mediators in human nasal polyps and cultured nasal epithelium.
Polyps are believed to be the source of mucus hypersecretion in chronic inflammation of the sinus. However, it is not clear which mucins are responsible for the hypersecretion of mucus by nasal polyps. We describe the over-expression of MUC8 mRNA in nasal polyps and the upregulation of MUC8 mRNA expression and downregulation of MUC5AC mRNA expression by inflammatory mediators. We found that the level of MUC8 mRNA, but not the level of MUC5AC mRNA, increased in nasal polyps. We also found that there was an increase in intracellular mucin in nasal polyps, compared to the normal nasal inferior turbinate. A mixture of inflammatory mediators increased MUC8 mRNA expression and decreased MUC5AC mRNA expression in cultured normal human nasal epithelial cells. Among inflammatory mediators, IL-4 is responsible for the decrease in MUC5AC mRNA and MUC5AC mucin secretion. These results indicate that MUC8 may be one of the major mucins secreted from the polyp epithelium and that it may play an important role in the pathogenesis of mucus hypersecretion in chronic sinusitis with polyps.
Seong
Je-Kyung
JK
Division of Laboratory Animal Medicine, Yonsei University College of Medicine, Seodaemun-gu, Seoul, South Korea.
Koo
Ja Seok
JS
Lee
Won Jae
WJ
Kim
Hee-Nam
HN
Park
Ji-Young
JY
Song
Kyoung Seob
KS
Hong
Ji Hun
JH
Yoon
Joo-Heon
JH
D002478:Cells, Cultured; D002908:Chronic Disease; D006801:Humans; D055271:Mucin 5AC; D009077:Mucins / Q000235:genetics* / Q000378:metabolism; D009093:Mucus / Q000378:metabolism; D009297:Nasal Mucosa / Q000378:metabolism / Q000473:pathology; D009298:Nasal Polyps / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012852:Sinusitis / Q000473:pathology; D015854:Up-Regulation / Q000235:genetics*
C524678:MUC5AC protein, human; C105059:MUC8 protein, human; D055271:Mucin 5AC; D009077:Mucins; D012333:RNA, Messenger