Exosomes from bone marrow mesenchymal stem cells regulate the balance of Foxp3+ Treg/Th17 in asthmatic mice / 中国组织工程研究

BACKGROUND: Imbalance of Th1/Th2 immune response is an crucial pathophysiological manifestation of asthma, but recent studies have proved that asthma also has a close correlation with the imbalance of Foxp3+Treg/Th17. Accumulating evidence indicate that the immunoregulatory capacity of mesenchymal stem cells are mainly related to exosomes secreted by the cells. OBJECTIVE: To observe the effect of bone marrow mesenchymal stem cell exosomes on Foxp3+Treg cells, Th17 T cells and airway inflammation of asthmatic mice as well as cytokines in the bronchoalveolar lavage fluid. METHODS: Twenty-seven BALB/c mice of SPF grade were randomly divided into three groups: normal control group, asthmatic model group, and exosomes group. Except the normal control group, each mouse in the other groups was sensitized by ovalbumin to establish asthma models. In the exosomes group, each mouse was intravenously administrated with exosomes at 21 days of sensitization. At 24 hours after the final administration of ovalbumin, the proportion of Foxp3+Treg and Th17 in the sleep of asthmatic mice as well as the expression of CTLA-4 and PD-1 in Foxp3+Treg cells were detected by flow cytometry. The total number of inflammatory cells, and the number of eosinophils, lymphocytes, monocytes and neutrophils in the bronchoalveolar lavage fluid were counted to analyze the degree of airway inflammation in the combination with pathological observation. We also detected the expression of interleukin-4,5,13,10,17 and interferon-γ in the bronchoalveolar lavage fluid as well as p27kip1in CD4+T cells. RESULTS AND CONCLUSION: (1) The proportion of Foxp3+Treg in splenic lymphocytes and the CTLA-4 and PD-1 expression in Foxp3+Treg were significantly higher in the exosomes group than the asthmatic model group (P < 0.01). (2) The proportion of Th17 in splenic lymphocytes was ranked as follows: asthmatic model group > exosomes group > normal control group (P < 0.01). (3) The total number of inflammatory cells and the number of eosinophils, lymphocytes, neutrophils and monocytes in the bronchoalveolar lavage fluid were ranked as follows: asthmatic model group > exosomes group > normal control group (P < 0.01). (4) Pathological observation of the lung showed that the asthmatic mice appeared to have severest airway inflammation. However, mesenchymal stem cell exosomes could significantly alleviate the airway inflammation. (5) The detection of cytokines in the bronchoalveolar lavage fluid showed that levels of interleukin 13 and interleukin 17 were significantly reduced (P < 0.05, P < 0.01), while the level of interleukin 10 increased (P < 0.01). (6) The p27kip1expression in the CD4+T cells was obviously higher in the exosomes group than the asthmatic model group. In conclusion, exosomes from bone marrow mesenchymal stem cells can reverse the imbalance of Foxp3+Treg/Th17 and significantly inhibit the airway inflammation in asthmatic mice.

Asymptomatic patients of chronic obstructive pulmonary disease in China / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Chronic obstructive pulmonary disease (COPD) has a variable natural history and not all individuals follow the same course. This study aimed to identify the prevalence and characteristics of asymptomatic COPD patients from a population-based survey in China.</p><p><b>METHODS</b>A multistage cluster sampling strategy was used in a population from seven different provinces/cities. All residents (over 40 years old) were interviewed with a standardized questionnaire and spirometry. Post-bronchodilator forced expiratory volume in 1 second (FEV(1))/forced vital capacity (FVC) of less than 70% was defined as the diagnostic criterion of COPD. All COPD patients screened were divided into symptomatic group and asymptomatic group according to the presence or absence of chronic respiratory symptoms. Socio-demographic, personal and exposure variables were collected and analyzed.</p><p><b>RESULTS</b>Among the 1668 patients who were diagnosed with COPD from the 25 627 sampling subjects, 589 (35.3%) were asymptomatic. The age, sex, body mass index (BMI), rural and urban distributions, smoking habit and education levels were similar in the two groups. A total of 64.7% of the asymptomatic patients had no comorbidities. Cardiovascular diseases and lung cancer were more common among symptomatic COPD patients than asymptomatic group. Asymptomatic COPD group were less likely to present with poor ventilation in the kitchen, a family history of respiratory disease and recurrent childhood cough. Asymptomatic COPD patients had significantly higher FEV(1) (73.1% vs. 61.0%), FVC (91.9% vs. 82.0%), and a higher ratio of FEV(1)/FVC (62.9% vs. 58.7%) (all P < 0.001) than symptomatic group. More asymptomatic patients were underdiagnosed (91.9% vs. 54.3%, P < 0.001) than symptomatic patients.</p><p><b>CONCLUSIONS</b>This large population-based survey confirmed a high prevalence of asymptomatic COPD patients in China. More use of spirometry screening test may be important to the early detection of COPD.</p>

The oxidative stress enhanced adenoviral E1A-involved transactivation of nuclear factor-kappaB / 中国应用生理学杂志

<p><b>OBJECTIVE</b>The relationship between latent adenovirus infection and airway inflammation have not been well documented. The aim of this study is to illustrate the roles of adenovirus E1A protein on the level of glutathione (GSH) in response to oxidative stress and the effect of the oxidant/antioxidant imbalance upon the transactivation of NF-kappaB triggered by E1A protein.</p><p><b>METHODS</b>Rat alveolar epithelial cell stably expressing adenoviral E1A or control plasmid were developed. For isolation of nuclear extracts, 5 x 10(5) cells were plated and grown overnight in 60 mm dishes. Experiments were repeated three times. The cell model of stably expressing adenoviral E1A was stimulated by H2O2. The level of GSH were measured. E1A positive clone was stimulated by LPS or TNF-alpha and treated with L-Buthionine-sulfoximine (BSO). The expression of NF-kappaB was measured by Western blot. Differences between groups were assessed for significance by Student' t test; multiple comparisons by the one-way ANOVA.</p><p><b>RESULTS</b>There is no difference of GSH level without stimulation between E1A-positive clones and E1A-negative clones. For E1A-positive clones, the level of GSH did not increase in response to H2O2 as E1A-negative clones. The quantitation by densitometry of the NF-kappaB expression in E1A-positive clones were (79.3 +/- 4.6), (80.3 +/- 3.8) respectively without treatment and were (81.8 +/- 3.9) - (89.9 +/- 1.6) and (94.1 +/- 1.9) - (99.8 +/- 1.6) respectively under LPS or TNF-alpha stimulation, which were significantly higher than that of the control group (68.3 +/- 3.8), (69.4 +/- 4.3) respectively without stimulation and (70.1 +/- 2.8) - (80.8 +/- 3.6), (73.4 +/- 4.9) - (83.2 +/- 6.7) respectively under stimulation. The quantitation by densitometry of the NF-kappaB expression in E1A-negative clones were (1.25 +/- 0.18) and (1.69 +/- 0.19) respectively under LPS and TNF-alpha-stimulation and (1.22 +/- 0.16) and (1.75 +/- 0.13) respectively upon treatment for LPS and TNF-alpha with BSO preincubation. There did not show difference upon treatment with LPS or TNF-alpha with or without BSO in E1A-negative cell clone. The quantitation by densitometry of the NF-kappaB expression in E1A-positive clone were (1.75 +/- 0.10) and (2.26 +/- 0.21) respectively upon treatment for LPS and TNF-alpha with BSO preincubation which were significantly higher than that of LPS or TNF-alpha-stimulation alone (1.35 +/- 0.12), (1.80 +/- 0.14) respectively.</p><p><b>CONCLUSION</b>These results indicate that E1A protein decreased GSH levels in oxidant stress and upregulated NF-kappaB transcription activity. The oxidant/antioxidant imbalance in rat alveolar epithelial cells enhances E1A-modulated transcriptional activation of NF-kappaB. The mechanism underlying transactivation of NF-kappaB involved by E1A may be related to oxidative stress.</p>

A study on the methodology regarding the prevalence survey of chronic obstructive pulmonary disease in China / 中华流行病学杂志

<p><b>OBJECTIVE</b>To explore the methodology on prevalence study of chronic obstructive pulmonary disease (COPD) in line with the world, to obtain accurate epidemic data of COPD in China.</p><p><b>METHODS</b>A national multi-center cross-sectional survey on prevalence, risk factors and burden of COPD was conducted in China. In each area, a population-based cluster sample of approximately 1450 individuals aged 40 years or older was interviewed, using standardized questionnaires that were revised on the methodology of burden of lung diseases (BOLD) study and according under the context of China. All participants were submitted to pre-bronchodilator spirometry. Those with airflow limitation received post-bronchodilator spirometry, physical examination, X-rays of chest and EKG (electrocardiogram) tests. The post-bronchodialators FEV1/FVC < 70% was identified as having COPD.</p><p><b>RESULTS</b>Investigation has been completed with the same standardized procedures by all sites, up to the requirement of quality control. Over 85.0% of the spirometry tests and 95.0% of questionnaires had met the criteria of quality control in each area. Overall, 95.2% of the data was valid with acceptable spirometry and questionaire, and the valid response rate was 79.0%.</p><p><b>CONCLUSION</b>The protocol was in line with the international standards, by which the prevalence of COPD in China was of adequate quality and valid.</p>

DNA vaccine encoding Der p 2 allergen generates immunologic protection in recombinant Der p 2 allergen-induced allergic airway inflammation mice model / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>DNA immunization is a promising novel type of immunotherapy against allergy. An estimated 79.2% patients with asthma, wheezing and/or rhinitis suffer from Dermatophagoides pteronyssinus group 2 (Der p 2) allegen. The aim of the present study was to determine whether DNA vaccine encoding Der p 2 could generate immunologic protection in recombinant Der p 2 (rDer p 2) allergen-induced allergic airway inflammation mice model and to understand the role of DNA vaccination in specific-allergen immunotherapy for asthma.</p><p><b>METHODS</b>After DNA vaccination, BALB/c mice were sensitized by intraperitoneal injection (i.p) and challenged by intranasal instillation of rDer p 2. The lung tissues were assessed using hematoxylin and eosin. Mucus-producing goblet cells were identifed using periodic acid-Schiff (PAS)/alcian blue. The total cell number and composition of bronchoalveolar lavage samples were determined. The levels of the cytokines IL-4 and IFN-gamma, as well as IgE and IgG2a in the serum were determined by enzyme-linked immunosorbent assay. Allergen-specific IL-4 and IFN-gamma production by spleen cells were also measured by enzyme-linked immunosorbent assay. Expression of signal transducer and activator of transcription 6 (STAT6) in splenocytes were determined by Western blot.</p><p><b>RESULTS</b>DNA vaccine encoding Der p 2 allergen inhibited extensive infiltration of inflammatory cells and production of mucin induced by allergen. The influx of eosinophils into the lung interstitium was significantly reduced after administration of DNA vaccine. Significant reductions of IL-4 and increase in levels of IFN-gamma in bronchoalveolar lavage fluid were observed. The allergen-specific IgE was markedly decreased in mice receiving DNA vaccination. Allergen could induce higher IFN-gamma, weaker IL-4 in cultured spleen cells from mice receiving DNA vaccine. DNA vaccination inhibited STAT6 expression of spleen cells induced by allergen.</p><p><b>CONCLUSION</b>These results indicated that DNA vaccine encoding Der p 2 allergen generates immunologic protection in recombinant Der p 2 allergen-induced allergic airway inflammation mice model with regulating the immune response towards a Th1-type reaction.</p>

Study on the prevalence rate of chronic obstructive pulmonary disease in northern part of Guangdong province / 中华流行病学杂志

<p><b>OBJECTIVE</b>To investigate the prevalence of chronic obstructive pulmonary disease (COPD) and its risk factors in population over 40 years old in northern part of Guangdong province.</p><p><b>METHODS</b>Using uniform scheme, procedures and questionnaire, a cluster-randomized-sampling survey for the population aged over 40 years in a rural area of Shaoguan in the northern part of Guangdong province was performed. Spirometry was performed for every participant, followed by a bronchodilatation test when bronchial obstruction was present.</p><p><b>RESULTS</b>There were 1468 cases with complete data from 1498 people aged >or= 40 years including 640 males, 828 females with an average age of 54.3 years old. The total prevalence of COPD was 12.0%. The prevalence of COPD in males was significantly higher than that in females (18.3% vs. 7.1%, P < 0.01). Only 80.7% of the patients with COPD presented one or more symptoms as cough, phlegm, or dyspnoea. Underdiagnosis of COPD would be quite serious. Only 26.1% of the cases was previously diagnosed to have chronic bronchitis, emphysema, or COPD. Smoking was an important risk factor to COPD and 78.4% of the patients with COPD were smokers. However, relation of biomass and COPD called for further investigation.</p><p><b>CONCLUSION</b>Prevalence of COPD was much higher than expected in the northern part of Guangdong while smoking was an most important risk factor of COPD. Lung function test seemed to be of great importance to COPD diagnosis, especially in the earlier period of COPD.</p>