Yunxiao Shang

Prevention and treatment of diarrhoea with Saccharomyces boulardii in children with acute lower respiratory tract infections

The aim of this study was to determine whether Saccharomyces boulardii prevents and treats diarrhoea and antibiotic-associated diarrhoea (AAD) in children. A total of 333 hospitalised children with acute lower respiratory tract infection were enrolled in a 2-phase open randomised controlled trial. During the 1st phase, all children received intravenous antibiotics (AB). They were randomly allocated to group A (S. boulardii 500 mg/day + AB, n=167) or group B (AB alone, n=166) and followed for 2 weeks. Diarrhoea was defined as ≥3 loose/watery stools/day during at least 2 days, occurring during treatment and/or up to 2 weeks after AB therapy had stopped. AAD was considered when diarrhoea was caused by Clostridium difficile or when stool cultures remained negative. In the 2nd phase of the study, group B patients who developed diarrhoea were randomly allocated to two sub-groups: group B1 (S. boulardii + oral rehydration solution (ORS)) and group B2 (ORS alone). Data from 283 patients were available for analysis. Diarrhoea prevalence was lower in group A than in group B (11/139 (7.9%) vs. 42/144 (29.2%); relative risk (RR): 0.27, 95% confidence interval (CI): 0.1-0.5). S. boulardii reduced the risk of AAD (6/139 (4.3%) vs. 28/144 (19.4%); RR: 0.22; 95% CI: 0.1-0.5). When group B patients developed diarrhoea (n=42), S. boulardii treatment during 5 days (group B1) resulted in lower stool frequency (P<0.05) and higher recovery rate (91.3% in group B1 vs. 21.1% in B2; P<0.001). The mean duration of diarrhoea in group B1 was shorter (2.31±0.95 vs. 8.97±1.07 days; P<0.001). No adverse effects related to S. boulardii were observed. S. boulardii appeared to be effective in the prevention and treatment of diarrhoea and AAD in children treated with intravenous antibiotics.

The effect of substance P on asthmatic rat airway smooth muscle cell proliferation, migration, and cytoplasmic calcium concentration in vitro

Airway remodeling and airway hyper-responsiveness are prominent features of asthma. Neurogenic inflammation participates in the development of asthma. Neurokinin substance P acts by binding to neurokinin-1 receptor (NK-1R). Airway smooth muscle cells (ASMC) are important effector cells in asthma. Increases in ASMC proliferation, migration, and cytoplasmic Ca2+ concentration are critical to airway remodeling and hyper-responsiveness. The effects of substance P on ASMC were investigated in Wistar rats challenged with a previously described asthmatic rat model. To exclude possible influences from other factors, the role of substance P was also investigated in primary cultured rat ASMC. Substance P and WIN62577-induced changes in cytoplasmic Ca2+ concentration were observed by fluorescence microscopy, and expression of Ca2+ homeostasis-regulating genes was assessed with real-time PCR. We found that cytoplasmic Ca2+ concentration increased in normal rat ASMC treated with substance P, but decreased in asthmatic rat ASMC treated with WIN62577, an antagonist of NK-1R. Real-time PCR analysis revealed increased Serca2 mRNA expression but decreased Ip3r mRNA expression after WIN62577 treatment in asthmatic rat ASMC. Flow cytometric analysis (FCM) revealed that most asthmatic rat ASMC stayed at G1 phase after combined treatment with WIN62577 and IL-13 in vitro. Transwell analysis suggested that ASMC migration was reduced after WIN62577 treatment. Therefore, we conclude that NK-1R is related to asthma mechanisms and a NK-1R antagonist downregulates calcium concentration in asthmatic ASMC by increasing Serca2 mRNA and decreasing Ip3r mRNA expression. The NK-1R antagonist WIN62577 inhibited ASMC IL-13-induced proliferation and ASMC migration in vitro and therefore may be a new therapeutic option in asthma.

Nerve growth factor exacerbates allergic lung inflammation and airway remodeling in a rat model of chronic asthma.

Nerve growth factor (NGF) is critical in the pathogenesis of allergic airway inflammation in vivo and induces proliferation of airway smooth muscle cells and matrix metalloproteinase-9 (MMP-9) expression in vitro. However, the effects of NGF on chronic pulmonary diseases of allergic origin remain unknown. To investigate the effects of NGF on lung inflammation and airway remodeling, 32 Wistar rats were randomly divided into four groups: control, NGF, ovalbumin (OVA) and anti-rat-β-NGF antibody (anti-NGF). Aerosolized OVA was administered to the rats in the NGF, OVA and anti-NGF groups to generate the asthmatic rat model, and NGF or anti-NGF was administered 3 h prior to OVA inhalation every two days. On day 70, bronchial responsiveness tests, bronchoalveolar lavage (BAL) and cell counting were conducted. The levels of serum OVA-specific immunoglobulin E (IgE) and of T-helper cell type-2 (Th2) cytokines [interleukin (IL)-4 and IL-13] in the BAL fluid were measured by enzyme-linked immunosorbent assay. The expression levels of NGF protein and MMP-9 mRNA, and the activity of MMP-9 in the lungs were detected by western blot analysis, quantitative polymerase chain reaction and gelatin zymography analysis, respectively. Our results showed that NGF significantly increased eosinophilic airway inflammation, persistent airway hyperresponsiveness (AHR), the serum levels of OVA-specific IgE and the levels of Th2 cytokines in the BAL fluid, and also increased the expression levels and activity of MMP-9. However, anti-NGF treatment significantly inhibited eosinophilic airway inflammation, persistent AHR and airway remodeling. The results showed that NGF may have exacerbated the development of airway inflammation, AHR and airway remodeling through a Th2 pathway and by increasing the level of MMP-9 expression. Therefore, anti-NGF is potentially beneficial for preventing and treating patients with asthma.

T Helper 17 Cells and Regulatory T-Cell Imbalance in Paediatric Patients with Asthma

Asthma is a chronic inflammatory disorder of the lung, which is thought to be determined by the balance between the T helper (Th)2 and Th1 responses. This study evaluated whether the balance between Th17 cells and regulatory T cells (Treg) was impaired in asthma patients. The proportion of peripheral blood Th17 cells of the total CD4+ cell population in asthma patients was significantly higher than in controls (mean ± SD 0.72 ± 0.5% versus 0.31 ± 0.4%, respectively). The proportion of peripheral Treg cells in asthma patients was significantly lower than in controls (mean ± SD 12.1 ± 4.6% versus 27.2 ± 7.5%, respectively). Analysis of mRNA generally confirmed the flow cytometry data, suggesting that the changes in cytokine levels were mediated at the transcription level. In paediatric asthma patients, the CD4+ T-cell phenotype was skewed toward the Th17 phenotype, suggesting that a Th17/Treg functional imbalance plays a role in asthma.

Gender and age affect the levels of exhaled nitric oxide in healthy children

Asthma is a chronic inflammatory disorder of the lung and diagnosis is difficult in children. The measurement of fractional exhaled nitric oxide (FeNO) may be useful in the diagnosis and monitoring of treatments. A number of factors affect FeNO levels and their influence varies across countries and regions. This study included 300 healthy students, aged from 6 to 14 years, who participated voluntarily. A comprehensive medical survey was used and measurements of FeNO levels and spirometric parameters were recorded in Shenyang, China. We observed that the median FeNO was 11 ppb (range, 8–16 ppb) in children from the northern areas of China. For males, the median level was 13 ppb (range, 9–18 ppb) and the median level was 10 ppb (range, 8–14 ppb) for females. There was a significant difference between males and females (P= 0.007) and age was correlated with FeNO (R2= 0.6554), while weight, height, body mass index (BMI), forced vital capacity (FVC), forced expiratory volume (FEV1), FEV1/FVC and peak expiratory flow (PEF) had no correlation with FeNO. In conclusion, the median FeNO is 11 ppb (range, 8–16 ppb) in male and female healthy children from northern areas of China and is affected by gender and age.

Epigallocatechin-3-gallate inhibits inflammation and epithelial‑mesenchymal transition through the PI3K/AKT pathway via upregulation of PTEN in asthma

Asthma is a chronic disease associated with hyper-responsiveness, obstruction and remodeling of the airways. Epithelial-mesenchymal transition (EMT) has an important role in these alterations and may account for the accumulation of subepithelial mesenchymal cells, thus contributing to airway hyperresponsiveness and remodeling. Epigallo-catechin-3-gallate (EGCG), which is a type of polyphenol, is the most potent ingredient in green tea, and exhibits antibacterial, antiviral, antioxidative, anticancer and chemopreventive activities. Recently, numerous studies have investigated the protective effects of EGCG against asthma and other lung diseases. In the present study, the role of EGCG in ovalbumin (OVA)-challenged asthmatic mice was determined. In addition, the inhibitory effects of EGCG against transforming growth factor (TGF)-β1-induced EMT and migration of 16HBE cells, and the underlying mechanisms of the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway, were investigated by immunofluorescence, Transwell, wound healing assay and western blot analysis, respectively. The results indicated that EGCG may suppress inflammation and inflammatory cell infiltration into the lungs of OVA-challenged asthmatic mice, and may also inhibit EMT via the PI3K/AKT signaling pathway through upregulating the expression of phosphatase and tensin homolog (PTEN) in vivo and in vitro. The present study also revealed the anti-migratory effects of EGCG in TGF-β1-induced 16HBE cells, thus suggesting it may reduce airway remodeling. The present study provides a novel insight into understanding the protective effects of EGCG on airway remodeling in asthma, and indicates that EGCG may be useful as an adjuvant therapy for bronchial asthma.

SMC3 may play an important role in atopic asthma development

As a common disease with a complex risk, including genetic and environmental factors, atopic asthma is prevalent but treatable. The aim of the study was to predict the underlying mechanism of asthma and identify target genes for the disease.

Vasoactive intestinal peptide inhibits airway smooth muscle cell proliferation in a mouse model of asthma via the ERK1/2 signaling pathway.

&NA; Asthma is a heterogeneous clinical syndrome characterized by airway inflammation, hyper‐responsiveness and remodeling. Airway remodeling is irreversible by current antiasthmatic drugs, and it is the main cause of severe asthma. Airway smooth muscle cells (ASMCs) act as the main effector cells for airway remodeling; the proliferation and hypertrophy of which are involved in airway remodeling. Caveolin (Cav)− 1 is present on the surface of ASMCs, which is involved in cell cycle and signal transduction regulation, allowing ASMCs to change from proliferation to apoptosis. The extracellular signal‐regulated kinase (ERK)1/2 signaling pathway is a common pathway regulated by various proliferative factors, which demonstrates a regulatory role in airway remodeling of asthma. There have been many studies on the correlation between vasoactive intestinal peptide (VIP) and airway reactivity and inflammation in asthma, but the functions and related mechanisms of ASMCs remain unclear. In this study, we established an airway remodeling model in asthmatic mice, and concluded that VIP inhibits airway remodeling in vivo. The in vitro effect of VIP on interleukin‐13‐induced proliferation of ASMCs was studied by examining the effects of VIP on expression of ERK1/2, phospho‐ERK1/2 and Cav‐1 in ASMCs, as well as changes in cell cycle distribution. VIP inhibited phosphorylation of the ERK1/2 signaling pathway and expression of Cav‐1 on ASMCs and decreased the proportion of S phase cells in the cell cycle, thus inhibiting the proliferation of ASMCs. This study provides a novel therapeutic mechanism for the treatment of asthma.

Expression of vitamin D receptor in bronchial asthma and its bioinformatics prediction

Vitamin D receptors (VDRs) are associated with the occurrence and development of asthma. The aim of the present study was to analyze the secondary structure and B-cell and T-cell epitopes of VDR using online prediction software and aid in the future development of a highly efficient epitope-based vaccine against asthma. Blood samples were collected from peripheral blood of asthmatic children. Reverse transcription quantitative-polymerase chain reaction (RT-qPCR) was performed to detect the expression of VDR in the peripheral blood. Mouse models of asthma were established. Hematoxylin and eosin staining was performed to observe the pathological alterations of the lungs of mice. Immunohistochemistry, western blot analysis and RT-qPCR were performed to detect the expression of VDR in the lungs of asthmatic mice. Online prediction software immune epitope database and analysis resource, SYFPEITHI and linear epitope prediction based on propensity scale and support vector machines were used to predict the B-cell and T-cell epitopes and the RasMol and 3DLigandSite were used to analyze the tertiary structure of VDR. RT-qPCR demonstrated that VDR expression in the peripheral blood of asthmatic children was decreased. Immunohistochemistry, western blotting and RT-qPCR demonstrated that VDR expression also decreased in the lungs of mouse models of asthma. VDR B-cell epitopes were identified at 37–45, 88–94, 123–131, 231–239, 286–294 and 342–350 positions of the amino acid sequence and VDR T-cell epitopes were identified at 125–130, 231–239 and 265–272 positions. A total of six B-cell epitopes and three T-cell epitopes for VDR were predicted by bioinformatics, which when validated, may in the future aid in immunological diagnosis and development of a targeted drug therapy for clinical asthma.

Epigallocatechin gallate improves airway inflammation through TGF‑β1 signaling pathway in asthmatic mice

The present study aimed to investigate the effect of epigallocatechin gallate (EGCG) on airway inflammation in mice with bronchial asthma, and the regulatory mechanism of transforming growth factor (TGF)-β1 signaling pathway, so as to provide theoretical basis for research and development of a novel drug for clinical treatment. Mouse models of bronchial asthma were established and injected with dexamethasone and EGCG via the caudal vein. 7 days later, bronchoalveolar tissue was collected for hematoxylin and eosin staining. Determination of airway resistance (AWR) and lung function in mice was detected. Serum was separated for cytometric bead array to detect the changes in inflammatory factors. Bronchoalveolar lavage fluid was collected for eosinophil and neutrophil counts. Fresh blood was obtained for flow cytometry to determine the percentages of Th17 and Treg cells. Bronchovesicular tissue was utilized for western blot assay and reverse transcription-quantitative polymerase chain reaction to determine the proteins and transcription factors in the TGF-β1 pathway. EGCG 20 mg/kg significantly reduced asthmatic symptoms, lung inflammatory cell infiltration, and the inflammatory factor levels of interleukin (IL)-2, IL-6 and tumor necrosis factor (TNF)-α. In addition, it increased the levels of inflammatory factors, including IL-10, diminished the percentage of Th17 cells, increased the percentage of Treg cells, and decreased the expression of TGF-β1 and phosphorylated (p)-Smad2/3 expression. Following the inhibition of the TGF-β1 receptor, the anti-inflammatory effect of EGCG disappeared, and the expression of TGF-β1 and p-Smad2/3 increased. EGCG attenuated airway inflammation in asthmatic mice, decreased the percentage of Th17 cells and increased the percentage of Treg cells. The anti-inflammatory effect of EGCG is achieved via the TGF-β1 signaling pathway.