Objective: To investigate the expression of Clara cell 10-KDa protein (CC010) in sinonasal mucosa of murine bacterial chronic rhinosinusitis (BCRS) model.
Method: A murine BCRS model was established by Streptococcus pneumoniae inoculation plus Merocel ostiomeatal obstruction. After 12 week's intervention, histological changes of sinonasal mucosa in BCRS model were examined by hematoxylin and eosin stain, periodic acid-schiff stain, and Masson-Trichrome stain. The mRNA and protein expression of CC10 in sinonasal mucosa were determined by reverse transcription polymerase chain reaction and immunohistochemistry methods. The number of CC10 positive cells in sinonasal epithelium was also counted.
Result: In BCRS model group, polymorphonuclear neutrophils (PMN), subepithelial collagen deposition, goblet cells, and epithelial thickness were significantly increased, compared with control group (P<0.01). However, CC10 positive cells, CC10 mRNA and protein expression in sinonasal mucosa of BCRS model group were significantly decreased, compared with control group (P<0.01). Moreover, the number of CC10 positive cells was significantly negatively correlated with PMN (r=-0.734, P<0.01), subepithelial collagen deposition (r=-0.776, P<0.01), epithelial goblet cells (r=-0.841, P<0.01), and epithelial thickness (r=-0.805, P<0.01), respectively. CC10 average grayscale value was significantly positively correlated with PMN (r=0.771, P<0.01), subepithelial collagen deposition (r=0.802, P<0.01), epithelial goblet cells (r=0.887, P<0.01), and epithelial thickness (r=0.855, P<0.01), respectively.
Conclusion: The expression of CC10 is downregulated in sinonasal mucosa in BCRS model. As an important endogenous modulin, CC10 might play a crucial role in the pathogenesis of chronic rhinosinusitis.