Objective To investigate the mRNA and protein expression of human β-defensin-2 (hBD-2) induced by lipopolysaccharide (LPS)，IL-1β and TNF-α in human airway primary epitheliums.Methods The bronchial primary epitheliums from human were stimulated with LPS，IL-1β and TNF-α respectively and then were harvested for hBD-2 expression detection.The mRNA expression of hBD-2 was detected by RT-PCR，and the protein expression by immunocytochemistry and western blot.Results There was a small expression of hBD-2 mRNA in human airway primary epitheliums before stimulation.The hBD-2 mRNA expression was significantly increased after 3 hours of LPS，IL-1β and TNF-α stimulation respectively and the expression increasement was in a dose dependent manner.The hBD-2 protein could be detected in cytoplasm after 4 hours of LPS (0.1 μg/mL)，IL-1β (1 ng/mL) and TNF-α (10 ng/mL) stimulation.Conclusions LPS and proinflammatory cytokines can induce the mRNA and protein expression of hBD-2 in a short time.The expression of hBD-2 may play an initial defense role against bacterial invasion.
【Abstract】 Objective To study the role of house dust mite ( HDM) induced airway epithelium TLR4 expression and T lymphocyte activation in asthmatic inflammation. Methods Thirty BALB/ c mice were randomly divided into an ovalbumin ( OVA) group, a HDMgroup, and a control group. The mice in the OVA group were sensitized with OVA and Al( OH) 3 , and repeatedly exposed to aerosolized OVA. The mice in the HDMgroup and the control group were sensitized and challenged with HDMand saline, respectively.Histopathology changes of pulmonary tissue and airway were observed under light microscope. Levels of IL-4, IL-5, IL-13, IL-17, and IFN-γin BALF were measured by ELISA. Total and differential cell counts in bronchoalveolar lavage fluid ( BALF) were also measured. The mRNA and protein expressions of TLR4 weredetected by quantitative real-time PCR and Western blot, respectively. Th1, Th2, and cells in the peripheral blood were detected by flow cytometry. Results Light microscope revealed eosinophil specific inflammatory cells infiltration around the peribronchovascular region,mucus gland hyperplasia, and airway mucous plug inthe OVA group. The HDM group showed more severe alveolar and intersititial congestion and neutrophils infiltration. The control group showed intact alveolus with few mucous plug and inflammatory cells.Compared with the OVA group, significant increases in the number of total cells and neutrophils, as well as significantly higher expression of IL-4, IL-5, IL-13, and IL-17 were detected in the HDMgroup ( P lt;0. 05) ,while IFN-γexpression had no significant change ( P gt;0. 05) . The expression of TLR4 mRNA and protein significantly increased in the HDMgroup( P lt; 0. 05) , and did not change significantly in the other two groups ( P gt;0. 05) . The percentages of Th2 and Th17 cells in peripheral blood in the HDMgroup were significantly higher than the OVA group ( P lt;0. 05) . Conclusion HDM may induce inflammatory cells infiltration andactivation of Th2 and Th17 lymphocyte cells via up-regulation of TLR4 expression in airway epithelium,which might play an important role in asthmatic inflammation.
ObjectiveTo observe repairing process of trachea epithelium cells in chlorine-induced airway epithelial injury.MethodsTwelve mice were exposed to chlorine gas and prepared the mice model of airway damage. Three mice were executed respectively on 2nd, 4th, 7th, 10th day after exposure to chlorine gas, and tracheal tissues were collected. In addition 3 normal mice served as control. Airway repair and cell proliferation were detected by EdU labeling method. The basal cell markers keratin 5 (K5), keratin 14 (K14) were adopted as the tracheal epithelial markers for locating the position of the proliferation of repairing cells. Morphological analysis was adopted to measure the proliferation rate as well as the recovery of the false stratified epithelium.ResultsIn the control group, cell proliferation rate was very low, all basal cells expressed K5, and most basal cells did not express K14. Most of epithelial cells shed from the trachea epithelium after exposure to chlorine gas. 2-4 days after chlorine exposure, K5 and K14 expression basal cells increased, K14 expression cells increased greatly. In the peak period of cell proliferation, only a small number of ciliated cells appeared in the repairing trachea area. Epithelial cells repaired fast and widely at the bottom of the trachea.ConclusionThe trachea residual basal cells play roles of progenitor cells and repair the airway epithelium after chlorine damage in mice.