Objective To explore the effects of Aspergillus fumigatus（A. fumigatus） spores on airway inflammation and responsiveness in asthmatic rats.Methods Seventy male Wistar rats were randomly divided into Ⅰ and Ⅱ groups（n=35 in each group），then Group Ⅰ and Group Ⅱ were subdivided into a normal control group（n=5），an asthma group（n=10），a spores-treated control group（n=10），and a spores-treated asthma group（n=10）.The rats were sensitized to ovalbumin（OVA） and challenged with aerosol OVA to establish the asthma model.The effects of A. fumigatus spores on asthmatic rats before and after OVA aerosol challenging were investigated in Group Ⅰ and Group Ⅱ，respectively.The parameters associated with bronchial epithelial damage were observed by total protein concentration in BALF measured by BCA method.Total and differential cell counts in BALF were also counted.The airway resistance and airway responsiveness were calculated by transpulmonary pressure and gas flow rate.Results In Group Ⅰ，the total protein in BALF in the asthma group treated with A. fumigatus spores before OVA challenging（Group CA） was increased remarkably compared to the asthma group（Group A1）[（1.125±0.254）μg/mL vs（0.825±0.173）μg/mL，Plt;0.01].The nonspecific airway resistances induced by different concentration of acetylcholine in Group CA ［（0.997±0.196）cm H2O•mL-1•s-1，（1.123±0.142）cm H2O•mL-1•s-1，（1.130±0.197）cm H2O•mL-1•s-1］were increased significantly compared to Group A1 [（0.655±0.089）cm H2O•mL-1•s-1，（0.687±0.048）cm H2O•mL-1•s-1，（0.821±0.043）cm H2O•mL-1•s-1]（all Plt;0.05）.In Group Ⅱ，however，the above parameters in the asthma group treated with A. fumigatus spores after OVA challenging（Group AC） were not dramatically increased compared with the asthma group（Group A2）（all Pgt;0.05）.The differences in the total and differential cell counts in BALF in Group CA were not remarkable compared to other subgroups in Group Ⅰ（all Pgt;0.05）.But the BALF neutrophil count in Group AC was increased obviously compared to Group A2 ［（2.488±0.420）×106 vs （0.936±0.459）×106，Plt;0.05］.Conclusion These data indicate that exposure to A. fumigatus spores before challenging causes aggravated epithelial damage and increased airway resistance in an asthma rat model.
Objective To explore the effects of prolonged Aspergillus fumigatus spores inhalation on airway inflammation and remodeling in rats with chronic obstructive pulmonary disease（COPD）.Methods Fifty Wistar rats were randomly divided into group A，B，C，D and E，(n=10 in each group) and group E was served as normal control.In group A，B，C and D，COPD models were established by intratracheal administration of lipopolysaccharide (LPS) combined with cigarette smoke exposure.The rats in group A，B and C were given intranasal inhalation of 1×106cfu spores，1×103cfu spores and 100 mL saline twice a week for consecutive 5 weeks，respectively，while the rats in group D were given no treatment.Bronchoalveolar lavage fluid(BALF) were collected for total and differential cell count，and interleukin-8（IL-8） and transforming growth factor-b(TGF-b) concentration measurement.The pathologic changes of lung tissue were observed by HE，PAS and Masson stainings.Results Pathological changes characteristic of COPD were found in group D.The total cell count，the percentage of neutrophile and lymphocyte in BALF in group A and B were higher than those in group C and D(all Plt;0.01).IL-8 and TGF-b in BALF in group A and B were higher than those in group C and D(all Plt;0.01).The pathologic score of airway inflammation in group A was higher than those in group B，C and D(all Plt;0.01)：The thickness of airway wall(WAt/Pbm) and airway smooth muscles(WAm/Pbm)，the collagen deposition in the total airway wall(WCt/Pbm) and in the outer airway wall(WCo/Pbm) and the percentage of goblet cells to epithelial cells in group A and B were higher than those in group C and D(all Plt;0.01).In group A and B，IL-8 was positively correlated with the percentage of neutrophile(r=0.856，Plt;0.01)，the pathologic score of airway inflammation(r＝0.884，Plt;0.01)，and the percentage of goblet cells to epithelial cells (r=0.702，Plt;0.05)，respectively.TGF-b was positively correlated with WAt/Pbm，WCt/Pbm，WCo/Pbm and the ratio of goblet cells to epithelial cells (r=0.706，Plt;0.05：r=0.802，Plt;0.01：r=0.876，Plt;0.01：r=0.713，Plt;0.05).Conclusion Prolonged inhalation of Aspergillus fumigatus spores can aggravate the airway inflammation and remodeling in rats with COPD.
Objective To explore the effects of prolonged inhalation of Aspergillus fumigatus ( Af)spores on epithelial cell injury and expression of epidermal growth factor receptor( EGFR) in airways of asthmatic rats. Methods 64 male Wistar rats were randomly divided into 8 groups, ie. chronic asthma group ( group A) , chronic asthma plus Af spores inhalation for 1 week ( group B) , 3 weeks ( group C) and 5 weeks ( group D) , chronic asthma plus saline inhalation for 5 weeks ( group E) , OVA-sensitized and salinechallenged group ( group F) , and OVA-sensitized and saline-challenged plus Af spores inhalation for 5 weeks ( group G) ( each n =8) . The airway resistance ( Raw) and change of Raw after acetylcholine provocation were detected using a computerized system. The concentrations of epidermal growth factor ( EGF) andtransforming growth factor alpha( TGF-α) in BALF were measured by ELISA. The extents of epithelial cell injury and goblet cell hyperplasia were evaluated on hematoxylin and eosin-stained( HE) and periodic acidschiff ( PAS) stained lung sections. The expression of EGFR in airway epithelia was demonstrated byimmunohistochemistry, and the level of EGFR protein in the rat lung tissues was measured by western blot.Results The concentration of EGF( pg/mL) ( 51. 72 ±8. 54, 68. 12 ±7. 85, 86. 24 ±9. 12, respectively)and TGF-α( pg/mL) ( 55. 26 ±9. 30, 75. 58 ±11. 56, 96. 75 ±14. 66, respectively) , detached/ inner perimeter of epithelium( % ) ( 11. 25 ±3. 12, 26. 45 ±5. 56, 28. 50 ±7. 50, respectively) , the ratio of goblet cell area to epithelial cell area ( % ) ( 16. 42 ±5. 24, 22. 64 ±6. 82, 36. 38 ±9. 21, respectively) , the integrated optical density ( IOD) of EGFR positive stain in airway epithelial cells ( 82 ±15,120 ±19, 165 ±21, respectively) , and the EGFR protein levels in lung tissues ( 0. 91 ±0. 26, 1. 61 ±0. 52, 2. 52 ±0. 78,respectively) in group B, C, and D were higher than those in group A, E, F and G( P lt; 0. 05 or P lt;0. 01) .The change rates of Raw( % ) ( 61. 91 ±5. 26, 84. 69 ±6. 38) in group C and D were higher than those in group A, E, F and G ( P lt; 0. 05 or P lt;0. 01) . The IOD of EGFR was positively correlated with detached/inner perimeter of epithelium( % ) and the ratio of goblet cell area to epithelial cell area( % ) ( r = 0. 692,P lt;0. 01; r = 0. 657, P lt; 0. 01, respectively) . Conclusion Prolonged inhalation of Aspergillus fumigatus spores can aggravate airway epithelial cell injury, up-regulate the expression of EGFR in airway epithelial cell and induce goblet cell hyperplasia, thus increase the airway responsiveness in rats with chronic asthma.
随着免疫抑制人群的增多、检测技术的发展, 深部真菌感染日益受到人们的关注。真菌中的曲霉属成了这些免疫功能低下患者致病性感染的重要原因, 而烟曲霉在侵袭性曲霉病例中最常见。侵袭力是烟曲霉菌极为重要的致病原因;病原菌侵入上皮、内皮细胞等组织细胞后才导致了可怕的侵袭性感染。从上世纪90 年代来, 对于侵袭的研究已逐步深入, 为探讨复杂的致病机制打下了基础。侵袭性烟曲霉病一般的致病过程认为是烟曲霉孢子被宿主吸入下呼吸道, 侵入呼吸道上皮细胞后发育成菌丝, 菌丝进一步生长, 可侵入血管、进入血液, 造成全身播散[ 1] 。因此曲霉与宿主细胞( 上皮细胞、内皮细胞等) 的相互作用成了致病过程的重要环节。目前对病原体与宿主细胞作用的研究取得了一些进展, 对阐明致病机制、研究治疗靶点等有重要意义。
Objective To observe the levels of von Willebrand factor ( vWF) expressed by human umbilical vein endothelial cells ( HUVECs) infected by aspergillus fumigatus ( AF) alone or treatment with cytochalasin D, N-cadherin monoclonal antibody, dexamethasone, respectively, so as to explore the mechanism of angioinvasion in invasive aspergillosis. Methods An in vitro model of HUVECs infected by AF hypha was established. The experiment included six groups, ie. a sham control group, a TNF-αgroup, an AF hypha group, a cytochalasin D group, a N-cadherin antibody group, and a dexamethasone group. Cell supernatants were collected to detect the levels of vWF at 2 h, 6 h, 12 h, and 18 h by enzyme linked immunosorbent assay ( ELISA) . Results Compared with that of vWF at 2 h, the level was higher at 18 h in the sham controlgroup and the TNF-αgroup, and higher at 6 h, 12 h, and 18 h in the other groups( P lt; 0. 05) . Compared with the sham control group, the level of vWF in each experiment group increased at 2 h, 6 h, 12 h, and 18 h except that in the N-cadherin antibody group at 2 h ( P lt; 0. 05) . The level of vWF in TNF-α group was higher than that in the AF hypha group at 2 h, but lower at 18 h. ( P lt; 0. 05) . The level of vWF was not significantly different between the cytochalasin D group and the AF hypha group at each time point. The level of vWF was lower in the N-cadherin antibody group than that in the AF hypha group at 2 h and 6 h ( P lt;0. 05) . The level of vWF was not significantly different between the dexamethasone group and the AF hypha group at each time point. Conclusion HUVECs infected by AF hypha overexpress vWF. N-cadherinmonoclonal antibody can reduce the expression of vWF, but cytochalasin D or dexamethasone has no significant effect on it.
ObjectiveTo explore the effect of Aspergillus fumigatus on airway eosinophilia and hyperresponsiveness in rat model of chronic asthma. MethodsWistar rats were sensitized by intraperitoneal injections with ovalbumin (OVA) followed by chronic inhalation of nebulized OVA or physiologic saline. Rats were administered via the airways with placebo or aerosolized Aspergillus fumigatus spores suspension mimicking chronic Aspergillus fumigatus exposure. The Penh after acetylcholine provocation was detected using WBP system. The concentrations of IL-5 and eotaxin in BALF were measured by ELISA. The extents of eosinophil infiltration were evaluated on hematoxylin and eosin-stained(HE) and Wright-Giemsa stained BALF cells smear. ResultsAspergillus fumigatus worsened allergic airway inflammation in OVA-challenged rats,as evidenced by enhanced bronchial responsiveness to inhaled acetylcholine and increased bronchial eosinophilia. Elevated airway eosinophilia corresponded with higher levels of IL-5 and eotaxin in the Aspergillus Fumigatus exposure group. Aspergillus fumigatus,however,did not affect bronchial responses,numbers of eosinophils,IL-5 and eotaxin levels in saline challenged mice. ConclusionThe Results show that chronic Aspergillus fumigatus exposure aggravates eosinophilic airway inflammation in asthma rats by enhancing IL-5 and eotaxin production. Aspergillus fumigatus also increases bronchial hyperresponsiveness in asthma rats.
ObjectiveTo explore the effects of Aspergillus fumigatus (A. fumigatus) on airway inflammation, airway responsiveness and total serum IgE in asthmatic rats. MethodsEighteen male Wistar rats were divided into three groups randomly, ie. a normal control group, an asthmatic model group, and an A. fumigatus group. The rats in the model group and the A.fumigatus group were sensititized and challenged with ovalbumin to establish asthmatic model. After establishment of asthmatic model, the rats in the A. fumigatus group were treated with chronic A. fumigatus spores inhalation. Subsequently, airway responsiveness/sensitivity to methacholine(Ach), levels of serum IgE and airway inflammation were assessed and compared among three groups. ResultsCompared with the asthmatic rats, the rats treated with A. fumigatus showed higher airway responsiveness (Penh/baselin value was significantly increased at the Mch concentration of 12.5, 25 and 50 mg/mL), increased inflammatory cells infiltration in pulmonary tissue slices and increased serum IgE level (P < 0.05). Most importantly, serum IgE level was detected in close relationship with PC100 which was defined as the dose of Mch causing 100% increase of enhance pause (Penh) value without Mch challenge (r=-0.873, P < 0.01). Serum IgE level was also closely related to the percentage of eosinophils in bronchoalveolar lavage fluid (r=0.937, P < 0.01). ConclusionsChronic A. fumigatus inhalation aggravates airway inflammation, bronchial hyperresponsiveness and serum IgE level in asthma. IgE may play an important role in facilitating the development of bronchial responsiveness and eosinophilic inflammation.
Objective To explore the method of radiolabeling anti-Aspergillus monoclonal antibody (WF-AF-1)with 99mTc,and evaluate the in vitro and in vivo characteristics of 99mTc labeled WF-AF-1 (99mTc-WF-AF-1). Methods 99mTc-WF-AF-1 was prepared with indirect-labeling method.The labeled product was identified using thin layer chromatography.Suspensions of Aspergillus fumigatus,Staphylococcus aureus and Candida albicans were incubated with 99mTc-WF-AF-1 to evaluate the specificity of the labeled antibody.Mice were injected with 3.7MBq of labeled product.The biodistribution was measured at 40min,2h,4h and 7h after injection. Results The labeling efficiency of 99mTc-WF-AF-1 was over 95%,and the labeled product was stable in serum and phosphate buffer solution.In vitro binding of 99mTc-WF-AF-1 revealed that the labeled Mab-WF-AF-1 preferentially binds to Aspergillus fumigatus. Biodistrbution data showed that the labeled antibody was deposited mainly in liver,kidneys and spleen.The radioactivity uptake in blood at 40min and 7h was (2.51±0.23)%ID/g and (0.53±0.13)%ID/g,respectively. Conclusions The labeling efficiency and stability of 99mTc-WF-AF-1 are high.The labeled antibody is excreted mainly through the liver and kidneys with fast clearance in blood in normal mice.