The Experimental Study About The Effects Of Bone Marrow On The Pathogenesis Of Asthma

ObjectiveTo observe the expressions of CD34~+cell in bone marrow(BM),peripheral blood(PB) and lung of OVA sensitized and challenged mice and detect the levels of IL-5 in BALF,blood serum and BM of these mice.Study the effects of bone marrow on the pathogenesis of asthma.MethodsMale Kunming mice (18-22g) were randomly divided into three groups.①Asthmatic group: ten mice were sensitized by injecting 10μg OVA and 10mg aluminum hydroxide intraperitoneally and challenged by inhaling aerosol 1%OVA to establish asthma model.②Sensitized group: ten mice were sensitized by the same way and inhaled aerosol NS.③Control group: ten mice were sensitized and challenged with NS. Outcome measurements were made 24h following the final challenge.Sections from lung tissue were stained with HE and counted the number of EOS.PB was collected to count the percentage of EOS.The percentages of CD34~+ cell in PB and BM were counted by flow cytometry.The expression of CD34~+ cell in lung was evaluated by immunohistochemistry.The levels of IL-5 in BALF,blood serum and BM were detected by ELISA.Results1. The number of EOS in lung and the percentage of EOS in PB of mice from asthmatic group were increased than those in control group. Compared with control group,the proportion of CD34~+cell in BM of mice from sensitized group was increased and further increased in asthmatic group.The number of EOS in lung was closely correlated with the percentage of EOS in PB and the proportion of CD34~+cell in bone marrow.2. Compared with control group and sensitized group,the proportion of CD34~+cell in PB of mice from asthmatic group was higher.And the number of CD34~+cell in lung also increased in asthmatic group .3. There was an increase in the level of IL-5 in BALF of mice from asthmatic group.But this was not seen in sensitized group.The level of IL-5 in blood serum of mice from sensitized group was increased and further increased in asthmatic group.IL-5 can be detected by ELISA in BM of mice from three groups.But there was no difference in the level of IL-5 among three groups.Conclusion1. BM plays an important part in the pathogenesis of asthma. Hemopoietic progenitor cells in BM of sensitized mice and asthmatic mice were increased in different levels. The number of EOS in lung was closely correlated with the percentage of EOS in PB and the proportion of CD34~+cells in bone marrow.2. The expressions of CD34~+ cell in PB and lung of asthmatic mice were more evident than normal mice. Progenitors in BM may egress from bone marrow,home to lung and play some part in the development of allergic inflammatory .3. There was an increase in the level of IL-5 in BALF of asthmatic mice. The level of IL-5 in blood serum of sensitized mice was increased and this was further increased in asthmatic mice. There was no difference in the level of IL-5 in BM among sensitized,asthmatic and normal mice.Compared with IL-5 in BALF,IL-5 in blood serum plays an more important part.But this effect may not be critical.The effect of IL-5 in BM should be further studied.