Studies on regulation mechanism of reconstructed IL-18 to hematopoietic system of mice with radiation lesions

To study the regulation effects of reconstructed IL-18 to hematopoietic system of mice with radiation lesions by the criteria of blood cellsnumber, expression of cell cycle progression (cyclinD1) and apoptosis-related genes (bcl-2 and bax) in bone marrow. Methods Before or after the radiation lesion mice model, induced by 4.0 Gy 60Co radiation, was established, the animals were injected with 0.5 mg IL-18. On the 14th day the periphery blood cells and bone morrow cells were counted and the cyclinDl, bcl-2 and bax mRNA expression levels in arrow mononuclear cell (MNC) of model mice were measured by in situ hybridization. Results in the IL-18 group, the bax mRNA expression was significantly decreased (P<0.01), but the number of periphery blood cells and bone marrow cells, cyclinDl and bcl-2 mRNA were significantly increased (P<0.01) than those in the control group. Conclusion IL-18 can restrain radiation lesion due to its enhancing effects on cyclinDl and bcl-2 mRNA expression, and show an inhibitory effect on bax mRNA expression. In this way, it prevents the blood cells from being injured, promotes immunity, and protects the organism.