ABSTRACT
OBJECTIVE@#The aim of this study was to determine the expression of GATA-3 and the level of Th1 and Th2 cytokines upon repeated exposure to staphylococcal enterotoxin B(SEB) of different concentrations in the maxillary sinus mucosa of rabbits.@*METHOD@#The rabbits were randomly divided into 2 groups (24 rabbits per group): low-dose SEB group and high-dose SEB group. The low-dose SEB group and high-dose SEB group received daily injections of 0.6 ng of SEB (2 ml) and 60 ng of SEB (2 ml) into the left maxillary sinus of rabbits for 28 days, respectively. Concurrent treatment of the right maxillary sinus with normal saline was used as a control. Six rabbits chosen randomly in two groups were killed on days 3, 7, 14, and 28, and to obtain the sinus mucosa from the two-side maxillary sinuses for measurement. Mucosal levels of IL-2, IL-4, IL-5, and IFN-γ were measured using ABC-ELISA. Tissue expression of GATA-3 were examined using Real-time PCR and immunohistochemistry.@*RESULT@#IFN-γ and IL-2 levels were significantly elevated in the high-dose SEB group compared with the low-dose SEB and control groups on days 7, 14, and 28 (P 0.05).@*CONCLUSION@#SEB promoted Th1 cytokines production at high concentrations, and enhanced Th2 cytokines expression and Th2 immune response at low concentrations.
Subject(s)
Animals , Male , Rabbits , Cytokines , Metabolism , Enterotoxins , Pharmacology , Enzyme-Linked Immunosorbent Assay , Interferon-gamma , Metabolism , Interleukin-2 , Metabolism , Interleukin-4 , Metabolism , Interleukin-5 , Metabolism , Maxillary Sinus , Metabolism , Nasal Mucosa , Metabolism , RNA, Messenger , Metabolism , Th1 Cells , Th2 Cells , Transcription Factors , MetabolismABSTRACT
<p><b>OBJECTIVE</b>To investigate the ultrastructure of ciliated epithelia and inflammatory changes upon repeated exposure to staphylococcal enterotoxin A (SEA) of different concentrations in the maxillary sinus mucosa of rabbits.</p><p><b>METHODS</b>The rabbits were randomly divided into 2 groups (24 rabbits per group): low-dose SEA group and high-dose SEA group. The low-dose SEA group and high-dose SEA group received daily injections of 0.6 ng of SEA (2 ml) and 60 ng of SEA (2 ml) into the left maxillary sinus of rabbits for 28 days, respectively. Concurrent treatment of the right maxillary sinus with normal saline was used as control. Six rabbits chosen randomly in two groups were examined by computed tomography (CT) scans and then sacrificed to obtain the sinus mucosa from the two-side of maxillary sinuses for histological assessment on days 3, 7, 14 and 28. To characterize the inflammatory changes of the sinus mucosa examined using light microscope, hematoxylin and eosin (HE) and toluidine blue staining was performed. Scanning and transmission electron microscopy were performed to observe ultrastructure of ciliated epithelia in the maxillary sinus mucosa. SPSS 13.0 software was used to analyze the data.</p><p><b>RESULTS</b>On days 14 and 28, CT images showed opacification of the left maxillary sinus in the high-dose SEA group. The percentage of epithelial disruption was (22.73 ± 5.72) % and (30.79 ± 4.30)% in the high-dose SEA group respectively, and were significantly greater than those in the low-dose SEA group (5.12% ± 1.98% and 5.38% ± 1.64%, q value was 10.079 and 19.132) and control group (4.08% ± 1.29% and 4.81% ± 1.62%, q value was 11.016 and 19.592, respectively, all P < 0.01). The subepithelial thickness in the high-dose SEA group was (113.34 ± 14.81)µm and (120.86 ± 12.35) µm respectively, and were significantly different from those of the low-dose SEA group [(71.08 ± 10.39)µm and (81.63 ± 9.32)µm, q value was 8.090 and 8.782] and control group [(37.45 ± 7.67)µm and (38.79 ± 7.68)µm, q value was 15.759 and 19.541, all P < 0.01]. Viewed under the electron microscope, loss of cilia was observed, a few compound cilia and cytoplasmic protrusion were found, an obvious stretching of the endoplasmic reticulum and an obvious turgescence of the mitochondria was also observed. However, in the low-dose SEA group on days 14 and 28, CT scan of the left maxillary sinus showed transparency; light microscopy observations of the maxillary sinus mucosa showed the number of eosinophils was markedly increased as compared with the high-dose SEA and control groups, the differences were significant (q value was 5.871 and 6.766 on day 14, and q value was 7.572 and 8.970 on day 28, respectively, all P < 0.05). But no significant differences were observed in epithelial disruption between the low-dose SEA and the control groups on days 14 and 28 (q value was 1.512 and 0.859 respectively, all P > 0.05); inordinate array and adhesion of cilia was observed, but cilia loss, compound cilia, cytoplasmic protrusions, mitochondrial swelling and endoplasmic reticulum stretching were not found.</p><p><b>CONCLUSIONS</b>SEA may induce allergic inflammation of the sinus mucosa without damaging the structure of ciliated epithelia at low concentration. Whereas SEA impairs the structure of mitochondria and endoplasmic reticulum in ciliated epithelial cells at high concentration, and results in cilia loss and epithelial disruption, which may be one of the main reasons to induce acute sinusitis.</p>
Subject(s)
Animals , Rabbits , Cilia , Physiology , Cost of Illness , Enterotoxins , Toxicity , Eosinophils , Epithelial Cells , Physiology , Leukocyte Count , Maxillary Sinus , Metabolism , Mucous Membrane , Physiology , SinusitisABSTRACT
OBJECTIVE@#To observe ultrastructure of maxillary sinus mucosa of experimental acute sinusitis in rabbits.@*METHOD@#Twenty-five rabbits were randomly divided into experimental group (20 rabbits) and blank control group (5 rabbits). We established a rhinogenic model of experimental acute sinusitis in experimental group. Five rabbits chosen randomly in experimental group were sacrificed and dissected after 1, 2, 3, and 4 weeks, and the tissue (0.3 cm x 0.3 cm) of sinus mucosa were prepared for visualization by transmission electron microscope (TEM). Animals in blank control group were sacrificed after 1 week.@*RESULT@#Under the transmission electron microscope, in the blank control group, cilia of maxillary sinus mucosa lined up in order without ciliary loss, no stretched endoplasmic reticulum or turgescent mitochondria was observed. However, in the experimental group, inordinate array and loss of cilia was observed, a few compound cilia and cytoplasmic protrusion were also found. Both endoplasmic reticulum and mitochondria were swelling, and the lymphocytes were infiltrating with fibroblast proliferation in the submucosa. There was statistically significant difference between the experimental group and the blank control group (P < 0.05). In the experimental group, the number of compound cilia increased from 1 to 4 weeks, and the amount of compound cilia of the mucosa at 3 and 4 weeks was significantly higher than that at 1 week (P < 0.05). Swelling of mitochondria and endoplasmic reticulum was severe at 2 weeks and abated gradually with time, the results at 2 weeks were different from those of experimental group at 4 weeks (P < 0.05).@*CONCLUSION@#The obstruction of nasal sinuses and the bacterial infection might lead to ultrastructural changes of maxillary sinus mucosa, and these ultrastructural changes were believed to the important processes of pathological changes in acute sinusitis.