ABSTRACT
BACKGROUND: The nasal mucosa is characterized by a multirow high prismatic ciliated epithelium representing the first barrier of the immune defense system against microbial and other environmental pathogenic influences. A number of nonspecific defense mechanisms, including the presence of lactoferrin, peroxidases, proteases, interferons, and lysozymes in nasal secretions, act to counter inflammatory processes. The surfactant proteins (SPs) known from the lungs are important components of the innate immune system. They also influence the rheology of fluids and reduce the surface tension of gas-fluid interphases. The objective of this study was to investigate the protein expression of all four SPs. A specific aim was detection and characterization of SP-C, which had previously not been confirmed in human nasal mucosa. METHODS: The expression of mRNA for SP-A, -B, -C and -D was investigated using reverse transcriptase polymerase chain reaction on samples of both healthy nasal mucosa and nasal mucosa altered by inflammatory processes (allergic rhinitis and chronic rhinosinusitis). The distribution of all four proteins was determined with monoclonal antibodies using Western blot analysis as well as immunohistochemical methods. RESULTS: The results show that all four SPs, including SP-C not detected before this, are nasal mucosa components. A shift was also observed in the expression behavior of the SP-A, -B, and -D in nasal mucosa with inflammatory changes. CONCLUSION: Based on these results, SPs appear to have an important function in immunologic and rheological process of the nasal mucosa and support the prospective therapeutic use of liposomal nasal sprays.
Subject(s)
Nasal Polyps/immunology , Protein Precursors/metabolism , Proteolipids/metabolism , Pulmonary Surfactant-Associated Protein A/metabolism , Pulmonary Surfactant-Associated Protein C/metabolism , Pulmonary Surfactant-Associated Protein D/metabolism , Rhinitis/immunology , Sinusitis/immunology , Adolescent , Adult , Aged , Chronic Disease , Female , Gene Expression Regulation , Humans , Immunity, Innate , Immunohistochemistry , Male , Middle Aged , Nasal Polyps/complications , Protein Precursors/genetics , Proteolipids/genetics , Pulmonary Surfactant-Associated Protein A/genetics , Pulmonary Surfactant-Associated Protein C/genetics , Pulmonary Surfactant-Associated Protein D/genetics , Reverse Transcriptase Polymerase Chain Reaction , Rhinitis/complications , Sinusitis/complications , Young AdultABSTRACT
PURPOSE: To investigate the histomorphology of the canine tear drainage system and to show the distribution of mucin MUC5AC within the tissue. METHODS: Conjunctiva and tear drainage systems of 19 long-nosed dogs were investigated histologically and ultrastructurally. The tissues were stained with eight different antibodies reactive against less glycosylated and highly-glycosylated MUC5AC. Results were compared with findings in human tissue received from 12 body donors. RESULTS: Except for a distinctly longer nasolacrimal duct and several accessory openings of the duct into the nasal cavity, the morphology of the canine tear drainage system is very similar to that of humans. MUC5AC in less- and highly-glycosylated forms was present in the conjunctival tissue of dogs as well of humans. Within the tear sac and the nasolacrimal duct only less-glycosylated MUC5AC could be found in dogs and in human. CONCLUSIONS: These findings demonstrate that the canine tear drainage system is very similar to its human equivalent. In particular the distribution of MUC5AC, supposed to play an important role within the pathogenesis of dry eye syndrome (DES), is the same as in humans. Therefore the canine model seems to be an appropriate model for further DES research.
