Objective To observe the effect of NLRP3 inflammasome inhibitor MCC950 intervention on airway Muc5ac level in asthmatic mice, and to explore the role and mechanism of NLRP3 inflammasome in asthmatic airway mucus hypersecretion. Methods A total of 50 SPF grade BALB/c female mice aged 6 - 8 weeks were randomly divided into normal control group (NS group), asthma model group (AS group), dexamethasone group (Dex group), MCC950 high-dose intervention group (MH group) and MCC950 low-dose intervention group (ML group), with 10 mice in each group. Furthermore, the bronchoalveolar lavage fluid (BALF) of mice in each group was counted by total cell count, associated with white blood cell different count. In addition, the concentrations of interleukin (IL)-18 and IL-1β in BALF were tested by enzyme-linked immunosorbent assay; The lung tissues were prepared into paraffin-embedded sections, which were then subject to hematoxylin-eosin (HE) staining, Alcian blue-periodic acid Schiff base staining and Masson staining to observe the pathological changes of lung tissues. Immunohistochemistry was used to detect the protein expression levels of Muc5ac, NLRP3 and caspase-1 in lung tissues. Real-time quantitative polymerase chain reaction was performed to detect the relative mRNA expressions of Muc5ac, NLRP3 and Caspase-1 in lung tissues. Results Compared with NS group, AS group showed significant increase in total cell count of BALF, the percentage of eosinophils, the infiltration score of inflammatory cells around the airway, the positive relative staining area of airway mucus and the deposition area of airway collagen fibers in mice (P<0.05), upregulated protein expression levels of Muc5ac, NLRP3 and Caspase-1 in lung tissues (P<0.05), elevated relative mRNA expressions of Muc5ac, NLRP3 and Caspase-1 in lung tissues (P<0.05), and raised concentrations of IL-18 and IL-1β in BALF (P<0.05). While compared with AS group, the above indicators were reduced in MH group and ML group (P<0.05). Moreover, in relative to Dex group, these indicators were increased in MH group ML group (P<0.05). In addition, no statistically significant difference was observed in the aforementioned indications between MH group and ML group.Conclusions MCC950 intervention can inhibit airway inflammation and airway mucus secretion in asthmatic mice. Its mechanism is speculated to be related to the suppression of NLRP3, Caspase-1, IL-18 and IL-1β expressions, downregulation of Muc5ac expression, and inhibition in airway mucus hypersecretion.
Objective To investigate the modulating roles of Clara cell secretory 16 kD protein ( CC-16) , transcription factor T-bet, and GATA-3 in airway inflammation of patients with asthma. Methods 25 patients with acute exacerbation of asthma were enrolled as an asthma group and 33 healthy volunteers were enrolled as control. The plasma levels of CC16, IFN-γ, and IL-4 were measured by enzyme-linked immunosorbent assay ( ELISA) . The mRNA expressions of T-bet and GATA-3 in the peripheral bloodmononuclear cells ( PBMCs) were measured by reverse transcription-polymerase chain reaction ( RT-PCR) .Results The levels of CC16 and IFN-γin the asthma group were lower than those in the control group [ ( 21. 96 ±7. 31 ) ng/mL vs. ( 64. 88 ±25. 27) ng/mL, ( 118. 73 ±22. 59) pg/mL vs. ( 145. 53 ±29. 50) pg/mL, both P lt;0. 01] . The IL-4 level in the asthma group was significantly higher than that in the control group [ ( 425. 22 ±4. 37) pg/mL vs. ( 69. 72 ±10. 15 ) pg/mL, P lt; 0. 01] . The T-bet mRNA expression and T-bet /GATA-3 ratio of PBMCs in the asthma group were significantly lower than those in the control group( both P lt; 0. 01) . The expression GATA-3 mRNA was significantly higher than that in the control group( P lt;0. 01) . The level of CC16 was positively correlated with T-bet mRNA expression and the ratio of T-bet /GATA-3 ( r =0. 792, 0. 761, respectively, P lt; 0. 01) . There was no correlation between CC16 and the GATA-3 mRNA expression ( P gt;0. 05) . Conclusions These results suggest that CC16 and T-bet play important protection roles in the pathogenesis of asthma. GATA-3, IFN-γ, and IL-4 also participate in the airway inflammation of asthma.
ObjectiveTo investigate the synergistic effect of cold stress plus particulate matter 2.5 (PM2.5) co-exposure on the occurrence of respiratory inflammation and the possible post-transcriptional regulation mechanism of cold inducible RNA-binding protein (CIRP).MethodsIn vivo and in vitro experiments were carried out, and the lung tissue specimens from human surgical resection were observed. The rat model and cultured airway epithelial cells 16HBE were respectively divided into four groups (n=8), namely blank control group, 5 °C/18 °C group, PM2.5 group and 5 °C/18 °C+PM2.5 group. The expression of mRNA and protein of representative inflammatory cytokines and CIRP of cultured airway epithelial cells and rat bronchial/pulmonary tissues were respectively detected by ELISA, qPCR, and Western blot. Furthermore, the temporal dynamics of CIRP distribution were observed by cellular immunofluorescence. Finally, immunohistochemical method was used to observe the localization and expression of CIRP in rat and human bronchial/pulmonary tissues at the same time.ResultsIn vivo experiments, the mRNA and protein expression levels of CIRP, interleukin-6, and tumor necrosis factor-α in 5 °C group and PM2.5 group were significantly higher than those in the control group (all P<0.05), while the expression level of mRNA and protein in 5 °C+PM2.5 group were increased most obviously (all P<0.01). The same rule also appeared in the experimental results of each group in the vitro experiment. In addition, CIRP was mainly located in the cell nucleus; compared with the control group, the intracellular shift of CIRP appeared in 18 °C group and PM2.5 group, while the migration phenomenon was most obvious in the 18 °C+PM2.5 group. In the immunohistochemistry of rat bronchus/pulmonary tissue, the expressions of CIRP in the 5 °C group and in the PM2.5 group were significantly higher than those in the control group, and the CIRP expression in 5 °C+PM2.5 group was increased most evidently. Moreover, CIRP was expressed in the bronchial epithelial mucosa of normal people and patients with chronic obstructive respiratory disease (COPD), and it is mainly located in the nucleus of airway mucosal epithelial cells. The CIRP expression of COPD patients was significantly higher than that in the normal population.ConclusionCold stress has a sensitizing effect on airway epithelial inflammatory response induced by PM2.5, and post-transcriptional regulation of CIRP translocation from nucleus to cytoplasm may be an important mechanism.
ObjectiveTo investigate the expressions of IL-10,tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) in serum and lung tissue of COPD rats in order to elucidate the potential mechanism of airway inflammation. MethodsForty-five healthy adult male SD rats were randomly divided into a COPD model group (n=30) and a normal control group (n=15). The COPD rat model was established by intratracheal instillation of lipopolysaccharide (LPS) and exposure to cigarette smoke for 28 days. The concentrations of IL-10,TNF-α and IFN-γ in serum and lung tissue were measured by ELISA. ResultsTNF-α level of serum and lung tissue in the COPD model group increased significantly compared with the control group(P<0.05),while the levels of IFN-γ and IL-10 decreased significantly[serum:(44.68±8.67) ng/L vs. (75.96±10.59) ng/L;lung tissue:(64.55±9.03) ng/L vs. (94.06±8.71) ng/L,P<0.01]. The level of IL-10 in serum and lung tissue was negatively correlated with TNF-α (serum:r=-0.67,lung tissue:r=-0.80,P<0.01). The level of IL-10 in serum and lung tissue was positively correlated with IFN-γ (serum:r=0.64,lung tissue:r=0.72,P<0.01). The level of IL-10 in serum and lung tissue was negatively correlated with the percentage of neutrophils(serum:r=-0.70,lung tissue:r=-0.67,P<0.01). ConclusionIn COPD rats,down regulation of IL-10 plays an important role in regulation of airway inflammation.
ObjectiveTo investigate the protecting effect of rosiglitazone for lung in airway-instillation- lipopolysaccharides and smoke-induced chronic obstructive pulmonary disease (COPD) rat models.MethodsFifty male Wistar rats with the SPF standard were randomly divided into 5 groups (n=10). The rats were treated by airway-instillation-lipopolysaccharides and exposing to smoking to establish COPD rat models excepted normal group, and the treatment groups were received gavage rosiglitazone of 0.1 mg/kg, 0.15 mg/kg, and 0.2 mg/kg rosiglitazone daily for 30 days, and the normal group or model group was received gavage normal saline. All rats were sacrificed after 30 days' treatment, and the lung tissue section was stained by hematoxylin and eosin. The mean linear intercept (MLI) and mean alveolar numbers (MAN) were measured in all groups. In addition, the protein levels of p-Stat3 and p-NF-κB were detected by immunohistochemistry.ResultsCompared with normal group, the inflammation and emphysema were observed in the lung of rats in model group, and the symptoms of the group treated with rosiglitazone were lighter than normal group. The lungs of rats treated with highest dose of rosiglitazone (0.2 mg/kg) were evaluated with lowest pathology assessment score among three treatment groups, but there was no significant difference of MLI or MAN among three treatment groups. Compared with normal group, the protein levels of p-Stat3 and p-NF-κB were increased in the lung and tracheal epithelium and lymphoid tissue of rats in model group, while the protein levels of p-NF-κB were decreased in these tissues and the protein levels of p-Stat3 were decreased in the lymphoid tissue after treatment with rosiglitazone, but the protein levels of p-Stat3 were not changed in the lung and tracheal epithelium.ConclusionRosiglitazone has a protective effect on the COPD rat models by inhibiting NF-κB pathway to reduce the inflammation of the lung parenchyma.
ObjectiveTo study immunodepression effect of bone marrow-derived mesenchymal stem cell (BMSC) on acute asthmatic airway inflammation by galectin-1 (gal-1) in vivo.MethodsEighty-five female BALB/c mice were equally randomized into normal control group, asthmatic group, BMSC treatment group, gal-1 treatment group and BMSC and gal-1 inhibitor group. Ovalbumin (OVA) was used to establish acute asthmatic model. Total cell number and differential cell analysis in each group in bronchoalveolar lavage fluid (BALF) were determined. Furthermore, hematoxylin-eosin and periodic-acid Schiff staining was used to compare airway inflammation among five groups. Measurement of cytokines, including interleukin (IL) -4, IL-5 and gal-1 in BALF and OVA specific IgE (OVA-IgE) in serum were evaluated by enzyme linked immunosorbent assay. Moreover, dendritic cell (DC) in lung tissue was sorted by immunomagnetic beads and its MAPK signal pathway was analyzed by western blotting among five groups.ResultsAccumulation of inflammation cells, particularly eosinophils around airway and in BALF was evident in asthmatic mouse model, meanwhile hyperplasia of Goblet cell was also obvious in asthmatic group. BMSC engraftment or gal-1 infusion significantly reduced airway inflammation and hyperplasia of Goblet cell and the number of inflammation cells in BALF, especially eosinophils attenuated dramatically. However, there was no effect on airway inflammation and hyperplasia of Goblet Cell by simultaneous infusion BMSC engraftment and gal-1 inhibitor. Compared to normal control group, the level of IL-4, IL-5 in BALF and OVA-IgE in serum was increased remarkably in asthmatic group, but the level of gal-1 reduced obviously. Moreover, infusion of BMSC or gal-1 could mitigate the level of IL-4, IL-5 in BALF and OVA-IgE in serum and increase the level of gal-1 in asthmatic mouse. However, infusion with both BMSC and gal-1 inhibitor exerted no effect on cytokine and OVA-IgE in asthmatic mouse. DC was sorted by immunomagnetic beads and western blotting was used to detect the expression of MAPK signal pathway among five groups. The expression of ERK phosphorylation in asthmatic group was much lower than that in normal control group. On the contrary, the expression of p38 phosphorylation was much higher than that in normal control group. BMSC engraftment or gal-1 infusion significantly activated the ERK pathway and inhibited the p38 MARP pathway on asthmatic mouse DC. Nevertheless, the expression of ERK phosphorylation and p38 phosphorylation for group with BMSC and gal-1 inhibitor infusion was between the level of asthmatic group and normal control group.ConclusionsBMSC infusion alleviates airway inflammation in asthmatic mouse, especially weakens eosinophils infiltration, and the underlying mechanism might be protective effect of gal-1 secreted by BMSC which plays a role in lung tissue DC and regulates the DC expression of MAPK signal pathway.
0bjective To study the effect of bacterial infection on acute exacerbation of chronic obstructive pulmonary disease(AECOPD)，and to compare the airway inflammation caused by different isolated bacteria．Methods A total of 159 sputum samples were collected from AECOPD patients diagnosed according to GOLD 2004 standard，in which conventional culture and identification of bacteria was conducted．The patients with purulent sputa were divided into different groups according to bacteria separated．Levels of IL-6．IL-8 and TNF-α in sputum supernatant were assayed and compared in different bacteria groups．the purulent sputum without isolated bacteria group(NG)and normal control group(NC)． Results One hundred and twenty-nine strains of bacteria were isolated in 159 qualified sputa，including 26 strains of Klebsiella pneumoniae(KB)，21 strains of Hemophilus influenza(Hi)，17 strains of Pseudomonas aeruginosa(PA)，37 strains of Haemophilus parainflb~enzae(HP)(mixed infection not included)and 28 strains of other bacteria．Among of all samples，20 were double infection of Haernophilus parainfluenzae with another bacterium．Ninety-seven purulent sputa were collected．According to bacteria isolated，these sputa were divided into five groups，named HP(24 samples)，Hi(20 samples)，PA(16 samples)，KB(19 samples)and NG(18 samples)．Contrast to NC，concentration of IL-8 and TNF-α rose in sputa from which PA，Hi，KB were isolated(Plt;0．05)．The level increased much more in sputa from which PA and Hi were isolated compared with KB(Plt;0．05)．Concentration of IL-6 rose in sputa of each group collected from AECOPD patients contrast to sputa collected from NC(Plt;0．05)，without significant differences among all other group except for NC．Conclusions Bacterial infection plays an important role in AECOPD characterized with high level of inflammatory factors especially when PA，Hi，KB were infected bacteria．This study provides evidence for antibacterial therapy in AECOPD patients．
Objective To investigate the expression of stromal cell derived factor-1 ( SDF-1) and the effects of budesonide suspension for inhalation ( Pulmicort Respules) in mice with asthma. Methods Thirty Kunming female mice were randomly divided into three groups, ie. a control group, an asthma group, and a pulmicort treatment group. The asthma group and the pulmicort treatment group were sensitized with ovalbumin ( OVA) by a combination of intraperitoneal injection and repeated OVA intranasal challenges to establish mouse asthma model. The pulmicort treatment group received 100μL pulmicort by intranasal administration before OVA challenge. The immunohistochemistry was used to estimate the expression of SDF-1 in lung tissues. HE staining and Wright-Giemsa staining method were used to assess inflammatory infiltration in the airway and bronchoalveolar lavage fluid ( BALF) respectively. Results The expression of SDF-1 in the asthma group increased significantly compared with the control group ( 0.48 ±0.03 vs. 0.21 ± 0.02, Plt;0.05) , and significantly decreased after the intervention with pulmicort ( 0.29 ±0.01 vs. 0.48 ± 0.03, Plt; 0.05 ) . Compared with control group, the infiltration of inflammatory cells in airway was significantly enhanced in the asthma group, and attenuated in the pulmicort treatment group. The total number of inflammatory cells and eosinophil, lymphocyte, neutrophil counts in BALF increased significantly in the asthma group compared with the control group, and decreased significantly after pulmicort intervention. Conclusion SDF-1 may play an important role in the recruitment of inflammatory cells in asthmatic airway and pulmicort may relieve airway inflammation by decreasing the expression of SDF-1.
ObjectiveExploring the potential causal effects and directions of insulin resistance (IR) and chronic airway inflammatory diseases, including asthma and chronic obstructive pulmonary disease (COPD), through two sample Mendelian randomization (MR). MethodsA total of 53 validated single nucleotide polymorphisms (SNPs) associated with IR were selected as instrumental variables. The inverse variance-weighted (IVW) method was used to model the causal association, and sensitivity analyses through leave-one-out analysis and pleiotropy testing were conducted to assess the relationship between IR and asthma and COPD. ResultsMR analysis revealed no significant causal effect of IR on asthma (IVW: OR=1.067, 95%CI 0.871 to 1.306, P=0.531) or COPD (IVW: OR=0.906, 95%CI 0.686 to 1.196, P=0.557). The results were consistent across sensitivity analyses and multiple pleiotropy tests, with no evidence of horizontal pleiotropy detected. ConclusionNo causal association was found between IR and the development of asthma or COPD. The relationship between these conditions may be influenced indirectly through complex interactions between metabolic and inflammatory pathways affecting disease progression.