Objective: To study the effect of macrophage inflammatory protein-1alpha(MIP-1alpha) and its mRNA on airway inflammation of mouse with induced asthma.
Methods: Seventy male BALB/C mice were randomly divided into the control group and asthma group (including 7 subgroups, 10 mice each). The control group included group A(24) (the lavaging subgroup was sacrificed 24 h after the last challenge) and group A(0) (the non-lavaging subgroup was sacrificed from 18 h to 24 h after the last challenge); asthma group included group B(3) (the lavaging subgroup was sacrificed 3 h after the last challenge), group B(8) (the lavaging subgroup was sacrificed 8 h after the last challenge), group B(24) (the lavaging subgroup was sacrificed 24 h after the last challenge), group B(36) (the lavaging subgroup was sacrificed 36 h after the last challenge) and group B(0) (the non-lavaging subgroup was sacrificed from 18 h to 24 h after the last challenge). In the experiment, the mice model of asthma was established by the ovalbumin (OVA) challenge methods. Eosinophils (EOS) numbers and differentiated cell numbers in bronchoalveolar lavage fluid (BALF) were counted; the concentrations of MIP-1alpha in serum and BALF were measured by sandwich enzyme-linked immunosorbent assay (sandwich ELISA); the protein expressions of MIP-1alpha were detected by immunohistochemical techniques; the mRNA expressions of MIP-1alpha were determined by in situ hybridization technique.
Results: (1) The concentrations of MIP-1alpha in BALF and serum of group B(3) [(30.2 +/- 4.2) pg/ml, (30.8 +/- 4.6) pg/ml], group B(8) [(35.3 +/- 4.9) pg/ml, (34.9 +/- 5.1) pg/ml], group B(24) [(42.9 +/- 5.8) pg/ml, (41.7 +/- 6.3) pg/ml] and group B(36) [(37.8 +/- 4.7) pg/ml, (35.7 +/- 4.9) pg/ml] were significantly higher than those of group A(24) [(20.9 +/- 3.8) pg/ml, (22.4 +/- 4.3) pg/ml] (P < 0.01); the concentrations of MIP-1alpha in BALF and serum went up at 3 h, reached peak at 24 h, and had descended at 36 h. (2) Immunohistochemistry showed that the protein expressions of MIP-1alpha around the bronchus of group B(0) [(26.4 +/- 6.2)%] were significantly elevated as compared to those of group A(0) [(10.3 +/- 2.5)%] (P < 0.01), the epithelial cell was the chief expression cell. (3) In situ hybridization showed that the mRNA expressions of MIP-1alpha around the bronchus of group B(0) [(23.9 +/- 4.2)%] were significantly increased when compared to those of group A(0) [(8.7 +/- 1.8)%] (P < 0.01), the epithelial cell was the chief expression cell. (4) There was a significant correlation between the concentrations of MIP-1alpha and the numbers of EOS in BALF and between the concentrations of MIP-1alpha and the percentage of EOS numbers in the total cell numbers (EOS%) in BALF.
Conclusions: MIP-1alpha protein and MIP-1alpha mRNA were found strongly expressed in mouse asthma model, the epithelial cell was the chief expression cell; the kinetic characteristic of MIP-1alpha showed that its level increased at 3 h, reached peak at 24 h and declined at 36 h; MIP-1alpha and EOS gathering had a significant correlation.