Characterization of air-liquid interface culture of A549 alveolar epithelial cells

Alveolar epithelia play an essential role in maintaining the integrity and homeostasis of lungs, in which alveolar epithelial type II cells (AECII) are a cell type with stem cell potential for epithelial injury repair and regeneration. However, mechanisms behind the physiological and pathological roles of alveolar epithelia in human lungs remain largely unknown, partially owing to the difficulty of isolation and culture of primary human AECII cells. In the present study, we aimed to characterize alveolar epithelia generated from A549 lung adenocarcinoma cells that were cultured in an air-liquid interface (ALI) state. Morphological analysis demonstrated that A549 cells could reconstitute epithelial layers in ALI cultures as evaluated by histochemistry staining and electronic microscopy. Immunofluorescent staining further revealed an expression of alveolar epithelial type I cell (AECI) markers aquaporin-5 protein (AQP-5), and AECII cell marker surfactant protein C (SPC) in subpopulations of ALI cultured cells. Importantly, molecular analysis further revealed the expression of AQP-5, SPC, thyroid transcription factor-1, zonula occludens-1 and Mucin 5B in A549 ALI cultures as determined by both immunoblotting and quantitative RT-PCR assay. These results suggest that the ALI culture of A549 cells can partially mimic the property of alveolar epithelia, which may be a feasible and alternative model for investigating roles and mechanisms of alveolar epithelia in vitro.

Interleukin-1beta induces MUC2/MUC5B gene expression in human nasal epithelial cells / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To demonstrate the effects of IL-1beta on MUC2/MUC5B gene expression in cultured human nasal epithelial cells.@*METHOD@#In passage-2 cultured human nasal epithelial cells, the mRNA levels of MUC2/MUC5B gene expression induced by IL-1 beta were determined by fluorescent quantitative RT-PCR.@*RESULT@#MUC2/MUC5B mRNAs were detected after 24 h of exposure to IL-1beta. MUC2 mRNA levels in IL-1 beta treatment [(39.26 +/- 6.10) x 10(4) copy/microg] were significantly higher than control [(5.70 +/- 4.16) x 10(4) copy/microg] (P < 0.01). MUC5BmRNA levels in IL-1beta treatment [(5.7 +/- 2.06) x 10(5) copy/microg] were significantly higher than control [(1.11 +/- 0.72) 10(5) copy/microg] (P < 0.05).@*CONCLUSION@#IL-1 beta increased MUC2/MUC5B mRNA levels in human nasal epithelial cells. These results suggest that IL-1beta may enhance mucin gene expression in cultured human nasal epithelial cells.

The expression of mucins gene in the human nasal polyps and allergic rhinitis / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To detect the mucin gene (MUC2, MUC5AC, MUC5B, MUC18 and MUC19) expression in the nasal polyps, allergic rhinitis (AR) and the normal nasal mucosa in human. To investigate the role and clinical significance of mucin gene in the pathogenesis of nasal polyps and AR patients.@*METHOD@#We obtained samples from 35 cases of nasal polyps, 18 cases of AR inferior turbinate and 18 cases of simple nasal septum deviation inferior turbinate. Specimens were analyzed with RT-PCR and Real-time FQ-RT-PCR.@*RESULT@#The results of RT-PCR and FQ-RT-PCR showed that the expression of MUC5AC, MUC5B in nasal polyps and AR patients was significantly higher than that in normal mucosa (P0.05). The expression of MUC2, MUC18 in nasal polyps and AR was not significantly different from that in normal mucosa (P>0.05). And the results of RT-PCR for MUC19 expression in AR was higher than that in nasal polyps group and normal group (P<0.05 or P<0.01).@*CONCLUSION@#MUC5AC and MUC5B are highly expressed in epithelium of human nasal polyps and AR, and they take part in mucus over-secretion in nasal polyps and AR. The expression of MUC19 in AR was higher than that in nasal polyps group and normal group. It indicates that the secretion of MUC19 in allergic rhinitis was on high level. There was no difference of the expression of MUC2 and MUC18 in nasal polyps group, AR group and in normal group.

Significance of MUC5B antibody in differential diagnosis between Aspergillus species and Mucorales of fungal sinusitis / 中华病理学杂志

<p><b>OBJECTIVE</b>To differentiate between Aspergillus species and Mucorales of fungal sinusitis by immunohistochemistry.</p><p><b>METHODS</b>Formalin-fixed paraffin-embedded tissue blocks of 66 cases of fungal sinusitis were retrieved from the archival files of Department of Pathology of Beijing Tongren Hospital during the period from 2001 to 2006. The samples included 29 cases of fungal balls, 12 cases of allergic fungal sinusitis, 24 cases of chronic invasive fungal sinusitis and 1 case of acute invasive fungal sinusitis. The types of fungi were 44 Aspergillus species (31 cases of A. fumigatus, 7 cases of A. flavus and 6 cases of A. terreus) and 22 Mucorales (14 cases of Mucor species and 8 cases of Rhizopus species). Immunohistochemistry was performed with MUC2, MUC5AC and MUC5B antibodies. The results were compared with histochemical study for periodic acid-Schiff (PAS) and Grocott methenamine silver (GMS) stains.</p><p><b>RESULTS</b>Immunohistochemical study for MUC5B showed that the positive rate of Aspergillus species was 90.9%, in contrast to 4.5% in Mucorales (P < 0.001). The expression of MUC2 and MUC5AC was completely negative, whereas PAS and GMS stains were positive in all cases.</p><p><b>CONCLUSION</b>MUC5B antibody appears to be a useful immunohistochemical marker for identifying fungal types in tissue sections, especially in distinguishing between Aspergillus species and Mucorales in fungal sinusitis.</p>

MUC5B expression in middle ear effusions: the main gel-forming mucin responsible for viscous properties of middle ear effusions

Several mucin genes are expressed in the middle ear mucosa resulting in the development of middle ear effusion. However, the detailed mucin protein expression in middle ear effusions has not been studied in individual effusions. This study aimed to explore the expression patterns of the 3 main secretory mucins, known to be expressed in the air-ways, in individual middle ear effusions with studying the possible correlation with the effusion viscosity. Middle ear effusions were collected under general anesthesia from 30 children with otitis media with effusion. The viscosity of individual effusions was studied. Mucins were extracted from the individual effusions and their antigenic identity was studied with ELISA. Mucoid effusions have significantly higher viscosity and mucin content than serous effusions. MUCs2, 5AC and 5B were expressed in middle ear effusions within a wide range. MUC5B was the most abundant mucin with significantly strong positive correlation with the viscosity of middle ear effusions. Middle ear epithelium expresses MUC5B as the major secretory mucin which is likely to be the main determinant of the viscosity, and hence physical and biological characteristics, of middle ear effusions. A secondary role is played by MUC5AC and, to a small extent, by MUC2. This could have significant clinical implications. MUCsSB, 5AC and 2 are expressed in middle ear effusions with MUC5B representing the major secretory mucin which is also the main determinant of mucin viscosity. The clinical implications of these findings need further studies