Effect of montelukast sodium intervention on airway remodeling and percentage of Th17 cells/CD4+CD25+ regulatory T cells in asthmatic mice / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the dynamic changes in the percentage of Th17 cells/CD4CD25regulatory T cells after intervention with montelukast sodium, a leukotriene receptor antagonist, in asthmatic mice and the association between them.</p><p><b>METHODS</b>Balb/c mice were randomly divided into blank group, asthma group, and montelukast sodium group. The asthmatic mouse model of airway remodeling was established by sensitization with intraperitoneal injection of chicken ovalbumin (OVA) and aluminum hydroxide suspension and aerosol inhalation of OVA. The mice in the blank group were given normal saline, and those in the montelukast sodium group were given montelukast sodium by gavage before aerosol inhalation. Eight mice were randomly sacrificed within 24 hours after 2, 4, and 8 weeks of aerosol inhalation. The pathological sections of lung tissue were used to observe the degree of airway remodeling. Flow cytometry was used to measure the percentages of Th17 cells and CD4CD25regulatory T cells in CD4T cells.</p><p><b>RESULTS</b>The asthma group and the montelukast sodium group had significantly higher bronchial wall thickness and smooth muscle thickness at all time points compared with the blank group (P<0.05). At 8 weeks of intervention, the montelukast sodium group had significantly greater improvements in the above changes compared with the asthma group (P<0.05). Compared with the blank group, the asthma group and the montelukast sodium group had significant increases in Th17 cells (positively correlated with airway remodeling) and significant reductions in CD4CD25regulatory T cells (negatively correlated to airway remodeling) at all time points (P<0.05). At 8 weeks of intervention, the montelukast sodium group had a significant reduction in the number of Th17 cells and a significant increase in the number of CD4CD25regulatory T cells compared with the asthma group (P<0.05).</p><p><b>CONCLUSIONS</b>Montelukast sodium intervention can alleviate airway remodeling and achieve better improvements over the time of intervention. The possible mechanism may be related to the improvement of immunologic derangement of CD4CD25regulatory T cells and inhibition of airway inflammation.</p>

Dynamic changes in percentages of CD4⁺ CD25⁺ regulatory T cells and Th17 cells in process of airway remodeling in mouse model of asthma / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the dynamic changes in Th17 cells and CD4⁺ CD25⁺ regulatory T cells (Treg) in the spleen and to analyze their relationship with airway remodeling.</p><p><b>METHODS</b>A total of 48 female specific pathogen-free Balb/c mice were randomly divided into control and asthmatic groups. To establish the asthmatic airway remodeling model, the mice were sensitized to ovalbumin (OVA) through intraperitoneal injection of OVA and aluminum hydroxide suspension and challenged by inhalation of aerosol OVA. The matched control group was treated with normal saline instead. In 24 hours after 2-week, 4-week, and 8-week aerosol inhalation, 8 mice were randomly selected from each group and sacrificed. Then histopathological examination of the left lung was performed to measure the degree of airway remodeling. The percentages of Th17 and CD4⁺ CD25⁺ Treg cells in total CD4(+) cells from the spleen were determined by flow cytometry.</p><p><b>RESULTS</b>In the asthmatic group, the ratios of total bronchial wall area to bronchial basement membrane perimeter (WAt/Pbm) and bronchial smooth muscle area to bronchial basement membrane perimeter (WAm/Pbm) significantly increased as the challenge proceeds (P<0.01). The percentage of Th17 cells derived from the cell suspension of the spleen gradually increased and it was positively correlated with the degree of asthmatic airway remodeling (P<0.01). The percentage of CD4⁺ CD25⁺ Treg cells from the suspension gradually decreased and it was negatively correlated with the degree of asthmatic airway remodeling (P<0.01).</p><p><b>CONCLUSIONS</b>In mice with asthma, as the challenge proceeds, the airway remodeling becomes more severe, the percentage of Th17 cells increases, and the percentage of CD4⁺ CD25⁺ Treg cells decreases. The immunological imbalance is possibly one of the important factors inducing airway remodeling.</p>