[The increased expression of stromal cell-derived factor-1 (SDF-1) alleviates airway inflammation in asthmatic rats by promoting the migration of bone marrow mesenchymal stem cells (BMSCs)].

Abstract

Objective To observe the correlation of stromal cell-derived factor 1 (SDF-1) with bone marrow mesenchymal stem cell (BMSCs) migration and airway inflammation in asthmatic rats. Methods Twenty-four clean SD rats were randomly divided into normal control (NC) group, model control (MC) group, and BMSCs group. Asthma model was established by OVA. In the BMSCs group, 1×10⁶ BMSCs (1 mL) were transplanted into the tail vein on the day the model was completed. Pathological changes in lung tissues were evaluated by HE staining. The count of inflammatory cells in bronchoalveolar lavage fluid(BALF) was evaluated by Wright-Giemsa staining. The concentrations of IL-4, IL-5, IL-13, IgE, IgG1 and IgG2a in BALF were tested by ELISA. The expression of SDF-1 and STAT6 mRNA in lung tissue was measured by real time quantitative PCR. The expression of SDF-1 protein in bronchial epithelial cells were evaluated by Immunofluorescence staining. The expression of SDF-1 and STAT6 protein in lung tissue were measured by Western blot analysis. Results Compared with the normal group, the number of relative inflammatory cell counts and the concentrations of IL-4, IL-5, IL-13, IgE, IgG1, and IgG2a in BALF of the MC group increased significantly. The mRNA and protein expression of SDF-1 and STAT6 in lung tissue increased significantly. Compared with the MC group, inflammatory cells and inflammatory cytokines of BALF of BMSCs group were decreased in numbers, as was the expression of SDF-1 and STAT6 in lung tissues. Compared with the MC group, the expression of SDF-1 gene in lung tissues was increased, as was the expression of SDF-1 protein in bronchial epithelial cells. Conclusion In the process of asthmatic inflammation, the expression of chemokine SDF-1 in the damaged site increases, and promotes the migration of exogenous BMSCs to the lung tissue of asthmatic rats. BMSCs can regulate immune imbalance of Th1/Th2 cells by homing to damaged lung tissue, thus inhibiting asthmatic airway inflammation.