Dexamethasone’s Influence On Thymus Activation Regulated Chemokine In Airway Smooth Muscle Cells Of Asthma Mice

Objective To observe the influence of expression of dexamethasone on thymus activation regulated chemokine (TARC) in asthma smooth muscle cells inasthmatic mice models. Methods Thirty-six male mice randomly divided into three groups: normal control group(group A), asthma model group(group B), and dexamethasone treated group (group C). The asthmatic mice models were established by OVA and AL (OH)3. BALF sediment total number of cells and eosinophils(EOS) count, HE-stained was used to observe the changes of pulmonary histopathology. The levels of TARC and IL-4in both serum and BALF were measured by enzyme-linked immunosorbent assay(ELISA),then the expression of TARC protein in airway smooth muscle cells was assessed with immunohistochemistry. Results The total cell numbers and EOS count of group B were significantly higher than those in group A and group C (P<0.01), EOS count of group C was higher than that of group A (P<0.05). The concentrations of TARC and IL-4in serum of group B were obviously higher than that in group A and group C (P<0.01). The concentrations of TARC and IL-4in BALF of group B was significantly higher than those in group A and group C (P<0.01); the concentrations of TARC in BALF of group C was higher than those in group A (P<0.01).The protein of TARC in airway smooth muscle cells of group B was significantly higher than that in group A and group C (P<0.01). In mice serum, strong positive correlations were found between TARC and IL-4(r=0.669, P<0.01); There were significant positive correlations between TARC and IL-4in BALF (r=0.845, P<0.01). Conclusions The expression of TARC in ASMC of asthma mice’ was significantly higher than those in normal control group, and may decrease after dexamethasone therapy. Dexamethasone may inhibit TARC expression through reducing secretion of IL-4.